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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.13 02-Aug-2011
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
9    2.  Two minor typos in pcre_internal.h have been fixed.
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, now that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
110    20. If /S is present twice on a test pattern in pcretest input, it now
111        *disables* studying, thereby overriding the use of -s on the command line
112        (see 14 above). This is necessary for one or two tests to keep the output
113        identical in both cases.
115    21. When (*ACCEPT) was used in an assertion that matched an empty string and
116        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
118    22. When an atomic group that contained a capturing parenthesis was
119        successfully matched, but the branch in which it appeared failed, the
120        capturing was not being forgotten if a higher numbered group was later
121        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
122        group 1 to "a", when in fact it should be unset. This applied to multi-
123        branched capturing and non-capturing groups, repeated or not, and also to
124        positive assertions (capturing in negative assertions does not happen
125        in PCRE) and also to nested atomic groups.
127    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
128        subject after a captured substring, to make it easier to tell which of a
129        number of identical substrings has been captured.
131    24. The way atomic groups are processed by pcre_exec() has been changed so that
132        if they are repeated, backtracking one repetition now resets captured
133        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
134        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
135        "aaa". Previously, it would have been "a". As part of this code
136        refactoring, the way recursive calls are handled has also been changed.
138    25. If an assertion condition captured any substrings, they were not passed
139        back unless some other capturing happened later. For example, if
140        (?(?=(a))a) was matched against "a", no capturing was returned.
142    26. When studying a pattern that contained subroutine calls or assertions,
143        the code for finding the minimum length of a possible match was handling
144        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
145        group 1 called group 2 while simultaneously a separate group 2 called group
146        1). A stack overflow occurred in this case. I have fixed this by limiting
147        the recursion depth to 10.
149    27. Updated RunTest.bat in the distribution to the version supplied by Tom
150        Fortmann. This supports explicit test numbers on the command line, and has
151        argument validation and error reporting.
153    28. An instance of \X with an unlimited repeat could fail if at any point the
154        first character it looked at was a mark character.
156    29. Some minor code refactoring concerning Unicode properties and scripts
157        should reduce the stack requirement of match() slightly.
159    30. Added the '=' option to pcretest to check the setting of unused capturing
160        slots at the end of the pattern, which are documented as being -1, but are
161        not included in the return count.
163    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
164        compiled something random. Now it gives a compile-time error (as does
165        Perl).
167    32. A *MARK encountered during the processing of a positive assertion is now
168        recorded and passed back (compatible with Perl).
170    33. If --only-matching or --colour was set on a pcregrep call whose pattern
171        had alternative anchored branches, the search for a second match in a line
172        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
173        matched the line "0102" twice. The same bug affected patterns that started
174        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
175        twice.
177    34. Previously, PCRE did not allow quantification of assertions. However, Perl
178        does, and because of capturing effects, quantifying parenthesized
179        assertions may at times be useful. Quantifiers are now allowed for
180        parenthesized assertions.
182    35. A minor code tidy in pcre_compile() when checking options for \R usage.
184    36. \g was being checked for fancy things in a character class, when it should
185        just be a literal "g".
187    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
188        appearance of a nested POSIX class supersedes an apparent external class.
189        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
190        unescaped square brackets may also appear as part of class names. For
191        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
192        more like Perl.
194    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
195        was because it thought it was \N{name}, which is not supported).
197    39. Add minix to OS list not supporting the -S option in pcretest.
199    40. PCRE tries to detect cases of infinite recursion at compile time, but it
200        cannot analyze patterns in sufficient detail to catch mutual recursions
201        such as ((?1))((?2)). There is now a runtime test that gives an error if a
202        subgroup is called recursively as a subpattern for a second time at the
203        same position in the subject string. In previous releases this might have
204        been caught by the recursion limit, or it might have run out of stack.
206    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
207        happen only once. PCRE was, however incorrectly giving a compile time error
208        "recursive call could loop indefinitely" because it cannot analyze the
209        pattern in sufficient detail. The compile time test no longer happens when
210        PCRE is compiling a conditional subpattern, but actual runaway loops are
211        now caught at runtime (see 40 above).
213    42. It seems that Perl allows any characters other than a closing parenthesis
214        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
215        has been changed to be the same.
217    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
218        as not to get warnings when autogen.sh is called. Also changed
219        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
221    44. To help people who use pcregrep to scan files containing exceedingly long
222        lines, the following changes have been made:
224        (a) The default value of the buffer size parameter has been increased from
225            8K to 20K. (The actual buffer used is three times this size.)
227        (b) The default can be changed by ./configure --with-pcregrep-bufsiz when
228            PCRE is built.
230        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
231            to be set at run time.
233        (d) Numerical values in pcregrep options can be followed by K or M, for
234            example --buffer-size=50K.
236        (e) If a line being scanned overflows pcregrep's buffer, an error is now
237            given and the return code is set to 2.
239    45. Add a pointer to the latest mark to the callout data block.
241    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
242        partial match of an empty string instead of no match. This was specific to
243        the use of ".".
245    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
246        complete match instead of a partial match. This bug was dependent on both
247        the PCRE_UTF8 and PCRE_DOTALL options being set.
250    Version 8.12 15-Jan-2011
251    ------------------------
253    1.  Fixed some typos in the markup of the man pages, and wrote a script that
254        checks for such things as part of the documentation building process.
256    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
257        --match-limit and --recursion-limit options (added for 8.11). In
258        particular, this made one of the standard tests fail. (The integer value
259        went into the wrong half of a long int.)
261    3.  If the --colour option was given to pcregrep with -v (invert match), it
262        did strange things, either producing crazy output, or crashing. It should,
263        of course, ignore a request for colour when reporting lines that do not
264        match.
266    4.  Another pcregrep bug caused similar problems if --colour was specified with
267        -M (multiline) and the pattern match finished with a line ending.
269    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
270        matched in multiline mode, the following line was shown as part of the
271        match. This seems wrong, so I have changed it.
273    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
274        the check for further matches in the same line (so they could be coloured)
275        to overrun the end of the current line. If another match was found, it was
276        incorrectly shown (and then shown again when found in the next line).
278    7.  If pcregrep was compiled under Windows, there was a reference to the
279        function pcregrep_exit() before it was defined. I am assuming this was
280        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
281        reported by a user. I've moved the definition above the reference.
284    Version 8.11 10-Dec-2010
285    ------------------------
287    1.  (*THEN) was not working properly if there were untried alternatives prior
288        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
289        backtracked to try for "b" instead of moving to the next alternative branch
290        at the same level (in this case, to look for "c"). The Perl documentation
291        is clear that when (*THEN) is backtracked onto, it goes to the "next
292        alternative in the innermost enclosing group".
294    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
295        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
296        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
297        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
298        (*THEN).
300    3.  If \s appeared in a character class, it removed the VT character from
301        the class, even if it had been included by some previous item, for example
302        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
303        of \s, but is part of the POSIX "space" class.)
305    4.  A partial match never returns an empty string (because you can always
306        match an empty string at the end of the subject); however the checking for
307        an empty string was starting at the "start of match" point. This has been
308        changed to the "earliest inspected character" point, because the returned
309        data for a partial match starts at this character. This means that, for
310        example, /(?<=abc)def/ gives a partial match for the subject "abc"
311        (previously it gave "no match").
313    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
314        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
315        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
316        has an implication that the given string is incomplete (because a partial
317        match is preferred over a full match). For this reason, these items now
318        give a partial match in this situation. [Aside: previously, the one case
319        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
320        match rather than a full match, which was wrong by the old rules, but is
321        now correct.]
323    6.  There was a bug in the handling of #-introduced comments, recognized when
324        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
325        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
326        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
327        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
328        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
329        places in pcre_compile().
331    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
332        comments when looking ahead for named forward references to subpatterns,
333        the only newline sequence it recognized was NL. It now handles newlines
334        according to the set newline convention.
336    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
337        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
338        cater for a lack of strerror(). These oversights have been fixed.
340    9.  Added --match-limit and --recursion-limit to pcregrep.
342    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
344    11. When the -o option was used, pcregrep was setting a return code of 1, even
345        when matches were found, and --line-buffered was not being honoured.
347    12. Added an optional parentheses number to the -o and --only-matching options
348        of pcregrep.
350    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
351        can match an empty string. The code to do it in pcretest and pcredemo
352        needed fixing:
354        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
355            only one byte after an empty string match just before CRLF (this case
356            just got forgotten; "any" and "anycrlf" were OK).
358        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
359            mode when an empty string match preceded an ASCII character followed by
360            a non-ASCII character. (The code for advancing by one character rather
361            than one byte was nonsense.)
363        (c) The pcredemo.c sample program did not have any code at all to handle
364            the cases when CRLF is a valid newline sequence.
366    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
367        as a starting offset was within the subject string. There is now a new
368        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
369        negative or greater than the length of the string. In order to test this,
370        pcretest is extended to allow the setting of negative starting offsets.
372    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
373        starting offset points to the beginning of a UTF-8 character was
374        unnecessarily clumsy. I tidied it up.
376    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
377        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
379    17. Nobody had reported that the --include_dir option, which was added in
380        release 7.7 should have been called --include-dir (hyphen, not underscore)
381        for compatibility with GNU grep. I have changed it to --include-dir, but
382        left --include_dir as an undocumented synonym, and the same for
383        --exclude-dir, though that is not available in GNU grep, at least as of
384        release 2.5.4.
386    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
387        characters from a string of bytes) have been redefined so as not to use
388        loops, in order to improve performance in some environments. At the same
389        time, I abstracted some of the common code into auxiliary macros to save
390        repetition (this should not affect the compiled code).
392    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
393        compile-time error is now given if \c is not followed by an ASCII
394        character, that is, a byte less than 128. (In EBCDIC mode, the code is
395        different, and any byte value is allowed.)
397    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
398        START_OPTIMIZE option, which is now allowed at compile time - but just
399        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
400        to pcregrep and other applications that have no direct access to PCRE
401        options. The new /Y option in pcretest sets this option when calling
402        pcre_compile().
404    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
405        back references. Groups containing recursive back references were forced to
406        be atomic by that change, but in the case of named groups, the amount of
407        memory required was incorrectly computed, leading to "Failed: internal
408        error: code overflow". This has been fixed.
410    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
411        pcretest.c, to avoid build problems in some Borland environments.
414    Version 8.10 25-Jun-2010
415    ------------------------
417    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
418        THEN.
420    2.  (*ACCEPT) was not working when inside an atomic group.
422    3.  Inside a character class, \B is treated as a literal by default, but
423        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
424        causes the error). The code is unchanged, but I tidied the documentation.
426    4.  Inside a character class, PCRE always treated \R and \X as literals,
427        whereas Perl faults them if its -w option is set. I have changed PCRE so
428        that it faults them when PCRE_EXTRA is set.
430    5.  Added support for \N, which always matches any character other than
431        newline. (It is the same as "." when PCRE_DOTALL is not set.)
433    6.  When compiling pcregrep with newer versions of gcc which may have
434        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
435        declared with attribute warn_unused_result" were given. Just casting the
436        result to (void) does not stop the warnings; a more elaborate fudge is
437        needed. I've used a macro to implement this.
439    7.  Minor change to pcretest.c to avoid a compiler warning.
441    8.  Added four artifical Unicode properties to help with an option to make
442        \s etc use properties (see next item). The new properties are: Xan
443        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
445    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
446        use Unicode properties. (*UCP) at the start of a pattern can be used to set
447        this option. Modified pcretest to add /W to test this facility. Added
448        REG_UCP to make it available via the POSIX interface.
450    10. Added --line-buffered to pcregrep.
452    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
453        studied, and the match started with a letter with a code point greater than
454        127 whose first byte was different to the first byte of the other case of
455        the letter, the other case of this starting letter was not recognized
456        (#976).
458    12. If a pattern that was studied started with a repeated Unicode property
459        test, for example, \p{Nd}+, there was the theoretical possibility of
460        setting up an incorrect bitmap of starting bytes, but fortunately it could
461        not have actually happened in practice until change 8 above was made (it
462        added property types that matched character-matching opcodes).
464    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
465        possible starting bytes for non-anchored patterns.
467    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
468        \R, and also a number of cases that involve Unicode properties, both
469        explicit and implicit when PCRE_UCP is set.
471    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
472        input, it could crash or give wrong results if characters with values
473        greater than 0xc0 were present in the subject string. (Detail: it assumed
474        UTF-8 input when processing these items.)
476    16. Added a lot of (int) casts to avoid compiler warnings in systems where
477        size_t is 64-bit (#991).
479    17. Added a check for running out of memory when PCRE is compiled with
480        --disable-stack-for-recursion (#990).
482    18. If the last data line in a file for pcretest does not have a newline on
483        the end, a newline was missing in the output.
485    19. The default pcre_chartables.c file recognizes only ASCII characters (values
486        less than 128) in its various bitmaps. However, there is a facility for
487        generating tables according to the current locale when PCRE is compiled. It
488        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
489        characters, are recognized by isspace() and therefore were getting set in
490        these tables, and indeed these tables seem to approximate to ISO 8859. This
491        caused a problem in UTF-8 mode when pcre_study() was used to create a list
492        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
493        which of course cannot start UTF-8 characters. I have changed the code so
494        that only real ASCII characters (less than 128) and the correct starting
495        bytes for UTF-8 encodings are set for characters greater than 127 when in
496        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
497        altogether.)
499    20. Added the /T option to pcretest so as to be able to run tests with non-
500        standard character tables, thus making it possible to include the tests
501        used for 19 above in the standard set of tests.
503    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
504        reference to a subpattern the other side of a comment that contains an
505        opening parenthesis caused either an internal compiling error, or a
506        reference to the wrong subpattern.
509    Version 8.02 19-Mar-2010
510    ------------------------
512    1.  The Unicode data tables have been updated to Unicode 5.2.0.
514    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
515        configured.
517    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
518        original author of that file, following a query about its status.
520    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
521        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
523    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
524        quantifier applied to a forward-referencing subroutine call, could compile
525        incorrect code or give the error "internal error: previously-checked
526        referenced subpattern not found".
528    6.  Both MS Visual Studio and Symbian OS have problems with initializing
529        variables to point to external functions. For these systems, therefore,
530        pcre_malloc etc. are now initialized to local functions that call the
531        relevant global functions.
533    7.  There were two entries missing in the vectors called coptable and poptable
534        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
535        I've fixed the data, and added a kludgy way of testing at compile time that
536        the lengths are correct (equal to the number of opcodes).
538    8.  Following on from 7, I added a similar kludge to check the length of the
539        eint vector in pcreposix.c.
541    9.  Error texts for pcre_compile() are held as one long string to avoid too
542        much relocation at load time. To find a text, the string is searched,
543        counting zeros. There was no check for running off the end of the string,
544        which could happen if a new error number was added without updating the
545        string.
547    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
549    11. \K was not working if it appeared in an atomic group or in a group that
550        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
551        \K is "not well defined" if used in an assertion. PCRE now accepts it if
552        the assertion is positive, but not if it is negative.
554    12. Change 11 fortuitously reduced the size of the stack frame used in the
555        "match()" function of pcre_exec.c by one pointer. Forthcoming
556        implementation of support for (*MARK) will need an extra pointer on the
557        stack; I have reserved it now, so that the stack frame size does not
558        decrease.
560    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
561        item in branch that calls a recursion is a subroutine call - as in the
562        second branch in the above example - was incorrectly given the compile-
563        time error "recursive call could loop indefinitely" because pcre_compile()
564        was not correctly checking the subroutine for matching a non-empty string.
566    14. The checks for overrunning compiling workspace could trigger after an
567        overrun had occurred. This is a "should never occur" error, but it can be
568        triggered by pathological patterns such as hundreds of nested parentheses.
569        The checks now trigger 100 bytes before the end of the workspace.
571    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
574    Version 8.01 19-Jan-2010
575    ------------------------
577    1.  If a pattern contained a conditional subpattern with only one branch (in
578        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
579        computed the wrong minimum data length (which is of course zero for such
580        subpatterns). This could cause incorrect "no match" results.
582    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
583        the pattern is reset in the first branch, pcre_compile() failed with
584        "internal error: code overflow at offset...". This happened only when
585        the reset was to the original external option setting. (An optimization
586        abstracts leading options settings into an external setting, which was the
587        cause of this.)
589    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
590        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
591        assertion pattern did not match (meaning that the assertion was true), it
592        was incorrectly treated as false if the SKIP had been reached during the
593        matching. This also applied to assertions used as conditions.
595    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
596        assertion subpattern, including such a pattern used as a condition,
597        unpredictable results occurred, instead of the error return
600    5.  The C++ GlobalReplace function was not working like Perl for the special
601        situation when an empty string is matched. It now does the fancy magic
602        stuff that is necessary.
604    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
605        removed. (These were left over from very, very early versions of PCRE.)
607    7.  Some cosmetic changes to the code to make life easier when compiling it
608        as part of something else:
610        (a) Change DEBUG to PCRE_DEBUG.
612        (b) In pcre_compile(), rename the member of the "branch_chain" structure
613            called "current" as "current_branch", to prevent a collision with the
614            Linux macro when compiled as a kernel module.
616        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
617            prevent a collision with the Linux macro when compiled as a kernel
618            module.
620    8.  In pcre_compile() there are some checks for integer overflows that used to
621        cast potentially large values to (double). This has been changed to that
622        when building, a check for int64_t is made, and if it is found, it is used
623        instead, thus avoiding the use of floating point arithmetic. (There is no
624        other use of FP in PCRE.) If int64_t is not found, the fallback is to
625        double.
627    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
628        2005 (difference between two addresses compared to an unsigned value).
630    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
631        custom one, because of the following reported problem in Windows:
633          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
634              under Win32.
635          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
636              therefore missing the function definition.
637          - The compiler thus generates a "C" signature for the test function.
638          - The linker fails to find the "C" function.
639          - PCRE fails to configure if asked to do so against libbz2.
641    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
642        messages were output:
644          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
645          rerunning libtoolize, to keep the correct libtool macros in-tree.
646          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
648        I have done both of these things.
650    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
651        most of the time, it *can* run out if it is given a pattern that contains a
652        runaway infinite recursion. I updated the discussion in the pcrestack man
653        page.
655    13. Now that we have gone to the x.xx style of version numbers, the minor
656        version may start with zero. Using 08 or 09 is a bad idea because users
657        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
658        interpreted as invalid octal numbers. I've updated the previous comment in
659        configure.ac, and also added a check that gives an error if 08 or 09 are
660        used.
662    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
663        causing partial matching to fail when the end of the subject matched \W
664        in a UTF-8 pattern where \W was quantified with a minimum of 3.
666    15. There were some discrepancies between the declarations in pcre_internal.h
667        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
668        their definitions. The declarations used "const uschar *" and the
669        definitions used USPTR. Even though USPTR is normally defined as "const
670        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
671        reported that: "This difference in casting confuses some C++ compilers, for
672        example, SunCC recognizes above declarations as different functions and
673        generates broken code for hbpcre." I have changed the declarations to use
674        USPTR.
676    16. GNU libtool is named differently on some systems. The autogen.sh script now
677        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
678        (FreeBSD).
680    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
681        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
682        comment: "Figure out how to create a longlong from a string: strtoll and
683        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
684        instance, but it only takes 2 args instead of 3!"
686    18. A subtle bug concerned with back references has been fixed by a change of
687        specification, with a corresponding code fix. A pattern such as
688        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
689        refers, was giving matches when it shouldn't. For example, xa=xaaa would
690        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
691        same bug. Such groups have to be quantified to be useful, or contained
692        inside another quantified group. (If there's no repetition, the reference
693        can never match.) The problem arises because, having left the group and
694        moved on to the rest of the pattern, a later failure that backtracks into
695        the group uses the captured value from the final iteration of the group
696        rather than the correct earlier one. I have fixed this in PCRE by forcing
697        any group that contains a reference to itself to be an atomic group; that
698        is, there cannot be any backtracking into it once it has completed. This is
699        similar to recursive and subroutine calls.
702    Version 8.00 19-Oct-09
703    ----------------------
705    1.  The table for translating pcre_compile() error codes into POSIX error codes
706        was out-of-date, and there was no check on the pcre_compile() error code
707        being within the table. This could lead to an OK return being given in
708        error.
710    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
711        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
712        in a Windows environment.
714    3.  The pcregrep --count option prints the count for each file even when it is
715        zero, as does GNU grep. However, pcregrep was also printing all files when
716        --files-with-matches was added. Now, when both options are given, it prints
717        counts only for those files that have at least one match. (GNU grep just
718        prints the file name in this circumstance, but including the count seems
719        more useful - otherwise, why use --count?) Also ensured that the
720        combination -clh just lists non-zero counts, with no names.
722    4.  The long form of the pcregrep -F option was incorrectly implemented as
723        --fixed_strings instead of --fixed-strings. This is an incompatible change,
724        but it seems right to fix it, and I didn't think it was worth preserving
725        the old behaviour.
727    5.  The command line items --regex=pattern and --regexp=pattern were not
728        recognized by pcregrep, which required --regex pattern or --regexp pattern
729        (with a space rather than an '='). The man page documented the '=' forms,
730        which are compatible with GNU grep; these now work.
732    6.  No libpcreposix.pc file was created for pkg-config; there was just
733        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
735    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
736        when UCP support is not needed, by modifying the Python script that
737        generates it from Unicode data files. This should not matter if the module
738        is correctly used as a library, but I received one complaint about 50K of
739        unwanted data. My guess is that the person linked everything into his
740        program rather than using a library. Anyway, it does no harm.
742    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
743        was a minimum greater than 1 for a wide character in a possessive
744        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
745        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
746        character. Chaos in the form of incorrect output or a compiling loop could
747        result.
749    9.  The restrictions on what a pattern can contain when partial matching is
750        requested for pcre_exec() have been removed. All patterns can now be
751        partially matched by this function. In addition, if there are at least two
752        slots in the offset vector, the offset of the earliest inspected character
753        for the match and the offset of the end of the subject are set in them when
754        PCRE_ERROR_PARTIAL is returned.
756    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
757        synonymous with PCRE_PARTIAL, for backwards compatibility, and
758        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
759        and may be more useful for multi-segment matching.
761    11. Partial matching with pcre_exec() is now more intuitive. A partial match
762        used to be given if ever the end of the subject was reached; now it is
763        given only if matching could not proceed because another character was
764        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
765        string "Z", which now yields "no match" instead of "partial match". In the
766        case of pcre_dfa_exec(), "no match" is given if every matching path for the
767        final character ended with (*FAIL).
769    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
770        if the pattern had a "must contain" character that was already found in the
771        earlier partial match, unless partial matching was again requested. For
772        example, with the pattern /dog.(body)?/, the "must contain" character is
773        "g". If the first part-match was for the string "dog", restarting with
774        "sbody" failed. This bug has been fixed.
776    13. The string returned by pcre_dfa_exec() after a partial match has been
777        changed so that it starts at the first inspected character rather than the
778        first character of the match. This makes a difference only if the pattern
779        starts with a lookbehind assertion or \b or \B (\K is not supported by
780        pcre_dfa_exec()). It's an incompatible change, but it makes the two
781        matching functions compatible, and I think it's the right thing to do.
783    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
784        so that the demonstration program is easily available in environments where
785        PCRE has not been installed from source.
787    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
788        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
789        library.
791    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
792        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
793        is not the first non-POSIX option to be added. Clearly some people find
794        these options useful.
796    17. If a caller to the POSIX matching function regexec() passes a non-zero
797        value for nmatch with a NULL value for pmatch, the value of
798        nmatch is forced to zero.
800    18. RunGrepTest did not have a test for the availability of the -u option of
801        the diff command, as RunTest does. It now checks in the same way as
802        RunTest, and also checks for the -b option.
804    19. If an odd number of negated classes containing just a single character
805        interposed, within parentheses, between a forward reference to a named
806        subpattern and the definition of the subpattern, compilation crashed with
807        an internal error, complaining that it could not find the referenced
808        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
809        [The bug was that it was starting one character too far in when skipping
810        over the character class, thus treating the ] as data rather than
811        terminating the class. This meant it could skip too much.]
813    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
814        /g option in pcretest when the pattern contains \K, which makes it possible
815        to have an empty string match not at the start, even when the pattern is
816        anchored. Updated pcretest and pcredemo to use this option.
818    21. If the maximum number of capturing subpatterns in a recursion was greater
819        than the maximum at the outer level, the higher number was returned, but
820        with unset values at the outer level. The correct (outer level) value is
821        now given.
823    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
824        PCRE did not set those parentheses (unlike Perl). I have now found a way to
825        make it do so. The string so far is captured, making this feature
826        compatible with Perl.
828    23. The tests have been re-organized, adding tests 11 and 12, to make it
829        possible to check the Perl 5.10 features against Perl 5.10.
831    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
832        pattern matches a fixed length string. PCRE did not allow this; now it
833        does. Neither allows recursion.
835    25. I finally figured out how to implement a request to provide the minimum
836        length of subject string that was needed in order to match a given pattern.
837        (It was back references and recursion that I had previously got hung up
838        on.) This code has now been added to pcre_study(); it finds a lower bound
839        to the length of subject needed. It is not necessarily the greatest lower
840        bound, but using it to avoid searching strings that are too short does give
841        some useful speed-ups. The value is available to calling programs via
842        pcre_fullinfo().
844    26. While implementing 25, I discovered to my embarrassment that pcretest had
845        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
846        study optimizations had never been tested with that matching function.
847        Oops. What is worse, even when it was passed study data, there was a bug in
848        pcre_dfa_exec() that meant it never actually used it. Double oops. There
849        were also very few tests of studied patterns with pcre_dfa_exec().
851    27. If (?| is used to create subpatterns with duplicate numbers, they are now
852        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
853        on the other side of the coin, they are no longer allowed to have different
854        names, because these cannot be distinguished in PCRE, and this has caused
855        confusion. (This is a difference from Perl.)
857    28. When duplicate subpattern names are present (necessarily with different
858        numbers, as required by 27 above), and a test is made by name in a
859        conditional pattern, either for a subpattern having been matched, or for
860        recursion in such a pattern, all the associated numbered subpatterns are
861        tested, and the overall condition is true if the condition is true for any
862        one of them. This is the way Perl works, and is also more like the way
863        testing by number works.
866    Version 7.9 11-Apr-09
867    ---------------------
869    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
870        (pcretest), all targets were linked against these libraries. This included
871        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
872        libraries. This caused unwanted dependencies to be created. This problem
873        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
874        pcretest is linked with readline.
876    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
877        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
878        moved outside it again, because FALSE and TRUE are already defined in AIX,
879        but BOOL is not.
881    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
882        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
884    4.  The pcregrep documentation said spaces were inserted as well as colons (or
885        hyphens) following file names and line numbers when outputting matching
886        lines. This is not true; no spaces are inserted. I have also clarified the
887        wording for the --colour (or --color) option.
889    5.  In pcregrep, when --colour was used with -o, the list of matching strings
890        was not coloured; this is different to GNU grep, so I have changed it to be
891        the same.
893    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
894        each matching line was coloured. Now it goes on to look for further matches
895        of any of the test patterns, which is the same behaviour as GNU grep.
897    7.  A pattern that could match an empty string could cause pcregrep to loop; it
898        doesn't make sense to accept an empty string match in pcregrep, so I have
899        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
900        seems to be how GNU grep behaves.
902    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
903        start or after a newline", because the conditional assertion was not being
904        correctly handled. The rule now is that both the assertion and what follows
905        in the first alternative must satisfy the test.
907    9.  If auto-callout was enabled in a pattern with a conditional group whose
908        condition was an assertion, PCRE could crash during matching, both with
909        pcre_exec() and pcre_dfa_exec().
911    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
912        used for matching.
914    11. Unicode property support in character classes was not working for
915        characters (bytes) greater than 127 when not in UTF-8 mode.
917    12. Added the -M command line option to pcretest.
919    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
921    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
923    16. Added comments and documentation about mis-use of no_arg in the C++
924        wrapper.
926    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
927        from Martin Jerabek that uses macro names for all relevant character and
928        string constants.
930    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
931        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
932        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
933        these, but not everybody uses configure.
935    19. A conditional group that had only one branch was not being correctly
936        recognized as an item that could match an empty string. This meant that an
937        enclosing group might also not be so recognized, causing infinite looping
938        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
939        with the subject "ab", where knowledge that the repeated group can match
940        nothing is needed in order to break the loop.
942    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
943        exec(), but without supplying a callout function, matching went wrong.
945    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
946        leak if the size of the offset vector was greater than 30. When the vector
947        is smaller, the saved offsets during recursion go onto a local stack
948        vector, but for larger vectors malloc() is used. It was failing to free
949        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
950        error, in fact).
952    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
953        heapframe that is used only when UTF-8 support is enabled. This caused no
954        problem, but was untidy.
956    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
957        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
958        included within another project.
960    24. Steven Van Ingelgem's patches to add more options to the CMake support,
961        slightly modified by me:
963          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
964              not building pcregrep.
966          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
967              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
969    25. Forward references, both numeric and by name, in patterns that made use of
970        duplicate group numbers, could behave incorrectly or give incorrect errors,
971        because when scanning forward to find the reference group, PCRE was not
972        taking into account the duplicate group numbers. A pattern such as
973        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
975    26. Changed a few more instances of "const unsigned char *" to USPTR, making
976        the feature of a custom pointer more persuasive (as requested by a user).
978    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
979        pcretest.c, inside #ifndefs, because it seems they are sometimes already
980        pre-defined.
982    28. Added support for (*UTF8) at the start of a pattern.
984    29. Arrange for flags added by the "release type" setting in CMake to be shown
985        in the configuration summary.
988    Version 7.8 05-Sep-08
989    ---------------------
991    1.  Replaced UCP searching code with optimized version as implemented for Ad
992        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
993        stage table and inline lookup instead of a function, giving speed ups of 2
994        to 5 times on some simple patterns that I tested. Permission was given to
995        distribute the MultiStage2.py script that generates the tables (it's not in
996        the tarball, but is in the Subversion repository).
998    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
999        scripts.
1001    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1002        a group with a zero qualifier. The result of the study could be incorrect,
1003        or the function might crash, depending on the pattern.
1005    4.  Caseless matching was not working for non-ASCII characters in back
1006        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1007        It now works when Unicode Property Support is available.
1009    5.  In pcretest, an escape such as \x{de} in the data was always generating
1010        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1011        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1012        truncation.
1014    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1016    7.  Added two (int) casts to pcregrep when printing the difference of two
1017        pointers, in case they are 64-bit values.
1019    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1020        test 2 if it fails.
1022    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1023        and a #define of that name to empty if it is not externally set. This is to
1024        allow users of MSVC to set it if necessary.
1026    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1027        the convenience functions in the pcre_get.c source file.
1029    11. An option change at the start of a pattern that had top-level alternatives
1030        could cause overwriting and/or a crash. This command provoked a crash in
1031        some environments:
1033          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1035        This potential security problem was recorded as CVE-2008-2371.
1037    12. For a pattern where the match had to start at the beginning or immediately
1038        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1039        pcre_dfa_exec() could read past the end of the passed subject if there was
1040        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1041        pcretest so that it places the subject at the end of its malloc-ed buffer.
1043    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1044        exec() might read past the end of the data buffer in UTF-8 mode.
1046    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1047        the data contained the byte 0x85 as part of a UTF-8 character within its
1048        first line. This applied both to normal and DFA matching.
1050    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1051        /^[^d]*?$/8 failed to match "abc".
1053    16. Added a missing copyright notice to pcrecpp_internal.h.
1055    17. Make it more clear in the documentation that values returned from
1056        pcre_exec() in ovector are byte offsets, not character counts.
1058    18. Tidied a few places to stop certain compilers from issuing warnings.
1060    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1061        supplied by Stefan Weber. I made a further small update for 7.8 because
1062        there is a change of source arrangements: the pcre_searchfuncs.c module is
1063        replaced by pcre_ucd.c.
1066    Version 7.7 07-May-08
1067    ---------------------
1069    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1070        a string to a long long, pretend we don't even have a long long." This is
1071        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1073    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1074        pre-7.6 versions, which defined a global no_arg variable instead of putting
1075        it in the RE class. (See also #8 below.)
1077    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1078        Lopes.
1080    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1082        (1) The include/exclude patterns were being applied to the whole pathnames
1083            of files, instead of just to the final components.
1085        (2) If there was more than one level of directory, the subdirectories were
1086            skipped unless they satisfied the include/exclude conditions. This is
1087            inconsistent with GNU grep (and could even be seen as contrary to the
1088            pcregrep specification - which I improved to make it absolutely clear).
1089            The action now is always to scan all levels of directory, and just
1090            apply the include/exclude patterns to regular files.
1092    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1093        --exclude_dir in the tests to avoid scanning .svn directories.
1095    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1096        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1097        doesn't support NULs in patterns.
1099    7.  Added some missing "const"s to declarations of static tables in
1100        pcre_compile.c and pcre_dfa_exec.c.
1102    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1103        caused by fix #2  above. (Subsequently also a second patch to fix the
1104        first patch. And a third patch - this was a messy problem.)
1106    9.  Applied Craig's patch to remove the use of push_back().
1108    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1109        matching function regexec().
1111    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1112        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1113        references. PCRE supports relative numbers with this syntax (I don't think
1114        Oniguruma does).
1116    12. Previously, a group with a zero repeat such as (...){0} was completely
1117        omitted from the compiled regex. However, this means that if the group
1118        was called as a subroutine from elsewhere in the pattern, things went wrong
1119        (an internal error was given). Such groups are now left in the compiled
1120        pattern, with a new opcode that causes them to be skipped at execution
1121        time.
1123    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1124        to the way PCRE behaves:
1126        (a) A lone ] character is dis-allowed (Perl treats it as data).
1128        (b) A back reference to an unmatched subpattern matches an empty string
1129            (Perl fails the current match path).
1131        (c) A data ] in a character class must be notated as \] because if the
1132            first data character in a class is ], it defines an empty class. (In
1133            Perl it is not possible to have an empty class.) The empty class []
1134            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1135            The negative empty class [^] matches any one character, independently
1136            of the DOTALL setting.
1138    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1139        non-existent subpattern following a character class starting with ']' and
1140        containing () gave an internal compiling error instead of "reference to
1141        non-existent subpattern". Fortunately, when the pattern did exist, the
1142        compiled code was correct. (When scanning forwards to check for the
1143        existencd of the subpattern, it was treating the data ']' as terminating
1144        the class, so got the count wrong. When actually compiling, the reference
1145        was subsequently set up correctly.)
1147    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1148        it was being rejected as not supported by pcre_dfa_exec(), even though
1149        other assertions are supported. I have made pcre_dfa_exec() support
1150        (*FAIL).
1152    16. The implementation of 13c above involved the invention of a new opcode,
1153        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1154        cannot be changed at match time, I realized I could make a small
1155        improvement to matching performance by compiling OP_ALLANY instead of
1156        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1157        on the OP_ANY path.
1159    17. Compiling pcretest on Windows with readline support failed without the
1160        following two fixes: (1) Make the unistd.h include conditional on
1161        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1163    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1164        ncurses library to be included for pcretest when ReadLine support is
1165        requested, but also to allow for it to be overridden. This patch came from
1166        Daniel Bergström.
1168    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1169        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1170        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1171        spotting this.
1174    Version 7.6 28-Jan-08
1175    ---------------------
1177    1.  A character class containing a very large number of characters with
1178        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1179        overflow.
1181    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1182        HAVE_LONG_LONG is not defined.
1184    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1185        bring them up to date and include new features. This patch includes:
1187        - Fixed PH's badly added libz and libbz2 support.
1188        - Fixed a problem with static linking.
1189        - Added pcredemo. [But later removed - see 7 below.]
1190        - Fixed dftables problem and added an option.
1191        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1192            HAVE_LONG_LONG.
1193        - Added readline support for pcretest.
1194        - Added an listing of the option settings after cmake has run.
1196    4.  A user submitted a patch to Makefile that makes it easy to create
1197        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1198        Makefile.am that cause it to include this special target, without
1199        affecting anything else. Note that the same mingw target plus all
1200        the other distribution libraries and programs are now supported
1201        when configuring with CMake (see 6 below) instead of with
1202        Configure/Make.
1204    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1205        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1206        exported in the Windows port". It has not yet been confirmed that the patch
1207        solves the problem, but it does no harm.
1209    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1210        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1211        with CMake, and also correct the comment about stack recursion.
1213    7.  Remove the automatic building of pcredemo from the ./configure system and
1214        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1215        of a program that users should build themselves after PCRE is installed, so
1216        building it automatically is not really right. What is more, it gave
1217        trouble in some build environments.
1219    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1222    Version 7.5 10-Jan-08
1223    ---------------------
1225    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1226        values in parens when parsing an RE using the C++ wrapper."
1228    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1229        Characters greater than 255 were excluded from the class instead of being
1230        included.
1232    3.  The same bug as (2) above applied to negated POSIX classes such as
1233        [:^space:].
1235    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1236        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1237        I have changed it.
1239    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1240        first named subpattern) and a construct such as (?&a) would reference the
1241        first named subpattern whose name started with "a" (in other words, the
1242        length check was missing). Both these problems are fixed. "Subpattern name
1243        expected" is now given for (?&) (a zero-length name), and this patch also
1244        makes it give the same error for \k'' (previously it complained that that
1245        was a reference to a non-existent subpattern).
1247    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1248        this is right because (?- can be followed by option settings as well as by
1249        digits. I have, however, made the messages clearer.
1251    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1252        than the number used in the conditional) now cause a compile-time error.
1253        This is actually not compatible with Perl, which accepts such patterns, but
1254        treats the conditional as always being FALSE (as PCRE used to), but it
1255        seems to me that giving a diagnostic is better.
1257    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1258        and messages.
1260    9.  Fix two occurrences of "backslash" in comments that should have been
1261        "backspace".
1263    10. Remove two redundant lines of code that can never be obeyed (their function
1264        was moved elsewhere).
1266    11. The program that makes PCRE's Unicode character property table had a bug
1267        which caused it to generate incorrect table entries for sequences of
1268        characters that have the same character type, but are in different scripts.
1269        It amalgamated them into a single range, with the script of the first of
1270        them. In other words, some characters were in the wrong script. There were
1271        thirteen such cases, affecting characters in the following ranges:
1273          U+002b0 - U+002c1
1274          U+0060c - U+0060d
1275          U+0061e - U+00612
1276          U+0064b - U+0065e
1277          U+0074d - U+0076d
1278          U+01800 - U+01805
1279          U+01d00 - U+01d77
1280          U+01d9b - U+01dbf
1281          U+0200b - U+0200f
1282          U+030fc - U+030fe
1283          U+03260 - U+0327f
1284          U+0fb46 - U+0fbb1
1285          U+10450 - U+1049d
1287    12. The -o option (show only the matching part of a line) for pcregrep was not
1288        compatible with GNU grep in that, if there was more than one match in a
1289        line, it showed only the first of them. It now behaves in the same way as
1290        GNU grep.
1292    13. If the -o and -v options were combined for pcregrep, it printed a blank
1293        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1294        does the same. The return code can be used to tell if there were any
1295        non-matching lines.
1297    14. Added --file-offsets and --line-offsets to pcregrep.
1299    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1300        infinitely looping recursion. The bug was that positive lookaheads were not
1301        being skipped when checking for a possible empty match (negative lookaheads
1302        and both kinds of lookbehind were skipped).
1304    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1305        inclusion of <windows.h> to before rather than after the definition of
1306        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1308    17. Specifying a possessive quantifier with a specific limit for a Unicode
1309        character property caused pcre_compile() to compile bad code, which led at
1310        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1311        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1312        caused the error; without that there was no problem.
1314    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1316    19. Added --enable-pcretest-libreadline.
1318    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1319        RE::GlobalReplace(). As a result, the number of replacements returned was
1320        double what it should be. I removed one of the increments, but Craig sent a
1321        later patch that removed the other one (the right fix) and added unit tests
1322        that check the return values (which was not done before).
1324    21. Several CMake things:
1326        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1327            the names libpcre and libpcreposix, not just pcre and pcreposix.
1329        (2) The above change means that pcretest and pcregrep are now correctly
1330            linked with the newly-built libraries, not previously installed ones.
1334    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1335        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1336        UTF-8 newline character). The key issue is that the pattern starts .*;
1337        this means that the match must be either at the beginning, or after a
1338        newline. The bug was in the code for advancing after a failed match and
1339        checking that the new position followed a newline. It was not taking
1340        account of UTF-8 characters correctly.
1342    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1343        character classes. PCRE was not treating the sequence [:...:] as a
1344        character class unless the ... were all letters. Perl, however, seems to
1345        allow any characters between [: and :], though of course it rejects as
1346        unknown any "names" that contain non-letters, because all the known class
1347        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1348        for example, whereas PCRE did not - it did not recognize a POSIX character
1349        class. This seemed a bit dangerous, so the code has been changed to be
1350        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1351        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1352        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1353        Perl does, and where it didn't before.
1355    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1356        Windows environments %n is disabled by default.
1359    Version 7.4 21-Sep-07
1360    ---------------------
1362    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1363        means that a class such as [\s] counted as "explicit reference to CR or
1364        LF". That isn't really right - the whole point of the change was to try to
1365        help when there was an actual mention of one of the two characters. So now
1366        the change happens only if \r or \n (or a literal CR or LF) character is
1367        encountered.
1369    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1370        of both had grown to the point where there were only 3 bits left.
1371        Fortunately, there was spare space in the data structure, and so I have
1372        moved the internal flags into a new 16-bit field to free up more option
1373        bits.
1375    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1376        but did not set the internal JCHANGED flag - either of these is enough to
1377        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1378        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1379        start sets both bits.
1381    4.  Added options (at build time, compile time, exec time) to change \R from
1382        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1384    5.  doc/pcresyntax.html was missing from the distribution.
1386    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1387        compatibility, even though it is no longer used.
1389    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1390        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1391        windows.h file is present (where different names are used). [This was
1392        reversed later after testing - see 16 below.]
1394    8.  Changed all #include <config.h> to #include "config.h". There were also
1395        some further <pcre.h> cases that I changed to "pcre.h".
1397    9.  When pcregrep was used with the --colour option, it missed the line ending
1398        sequence off the lines that it output.
1400    10. It was pointed out to me that arrays of string pointers cause lots of
1401        relocations when a shared library is dynamically loaded. A technique of
1402        using a single long string with a table of offsets can drastically reduce
1403        these. I have refactored PCRE in four places to do this. The result is
1404        dramatic:
1406          Originally:                          290
1407          After changing UCP table:            187
1408          After changing error message table:   43
1409          After changing table of "verbs"       36
1410          After changing table of Posix names   22
1412        Thanks to the folks working on Gregex for glib for this insight.
1414    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1415        unicode-properties was also set.
1417    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1419    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1420        checked only for CRLF.
1422    14. Added casts to pcretest.c to avoid compiler warnings.
1424    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1426    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1427        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1428        entirely. This removes changes made in 7 above.
1430    17. The CMake files have been updated, and there is now more information about
1431        building with CMake in the NON-UNIX-USE document.
1434    Version 7.3 28-Aug-07
1435    ---------------------
1437     1. In the rejigging of the build system that eventually resulted in 7.1, the
1438        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1439        brackets there is not right, since it causes compilers to look for an
1440        installed pcre.h, not the version that is in the source that is being
1441        compiled (which of course may be different). I have changed it back to:
1443          #include "pcre.h"
1445        I have a vague recollection that the change was concerned with compiling in
1446        different directories, but in the new build system, that is taken care of
1447        by the VPATH setting the Makefile.
1449     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1450        when the subject happened to end in the byte 0x85 (e.g. if the last
1451        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1452        characters but of course it shouldn't be taken as a newline when it is part
1453        of another character. The bug was that, for an unlimited repeat of . in
1454        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1455        characters when looking for a newline.
1457     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1459     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1460        in debug output.
1462     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1463        long printing in the pcrecpp unittest when running under MinGW.
1465     6. ESC_K was left out of the EBCDIC table.
1467     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1468        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1469        limit also applies to "virtual nesting" when a pattern is recursive, and in
1470        this case 1000 isn't so big. I have been able to remove this limit at the
1471        expense of backing off one optimization in certain circumstances. Normally,
1472        when pcre_exec() would call its internal match() function recursively and
1473        immediately return the result unconditionally, it uses a "tail recursion"
1474        feature to save stack. However, when a subpattern that can match an empty
1475        string has an unlimited repetition quantifier, it no longer makes this
1476        optimization. That gives it a stack frame in which to save the data for
1477        checking that an empty string has been matched. Previously this was taken
1478        from the 1000-entry workspace that had been reserved. So now there is no
1479        explicit limit, but more stack is used.
1481     8. Applied Daniel's patches to solve problems with the import/export magic
1482        syntax that is required for Windows, and which was going wrong for the
1483        pcreposix and pcrecpp parts of the library. These were overlooked when this
1484        problem was solved for the main library.
1486     9. There were some crude static tests to avoid integer overflow when computing
1487        the size of patterns that contain repeated groups with explicit upper
1488        limits. As the maximum quantifier is 65535, the maximum group length was
1489        set at 30,000 so that the product of these two numbers did not overflow a
1490        32-bit integer. However, it turns out that people want to use groups that
1491        are longer than 30,000 bytes (though not repeat them that many times).
1492        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1493        made it possible to implement the integer overflow checks in a much more
1494        dynamic way, which I have now done. The artificial limitation on group
1495        length has been removed - we now have only the limit on the total length of
1496        the compiled pattern, which depends on the LINK_SIZE setting.
1498    10. Fixed a bug in the documentation for get/copy named substring when
1499        duplicate names are permitted. If none of the named substrings are set, the
1500        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1501        empty string.
1503    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1504        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1505        because the ] is interpreted as the first data character and the
1506        terminating ] is not found. PCRE has been made compatible with Perl in this
1507        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1508        cause memory overwriting.
1510    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1511        string has been matched (to stop an infinite loop). It was not recognizing
1512        a conditional subpattern that could match an empty string if that
1513        subpattern was within another subpattern. For example, it looped when
1514        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1515        condition was not nested. This bug has been fixed.
1517    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1518        past the start of the subject in the presence of bytes with the top bit
1519        set, for example "\x8aBCD".
1521    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1522        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1524    14. Optimized (?!) to (*FAIL).
1526    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1527        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1528        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1529        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1530        does: it's just the validity check that is more restrictive.
1532    16. Inserted checks for integer overflows during escape sequence (backslash)
1533        processing, and also fixed erroneous offset values for syntax errors during
1534        backslash processing.
1536    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1537        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1539    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1540        caused an overrun.
1542    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1543        something other than just ASCII characters) inside a group that had an
1544        unlimited repeat caused a loop at compile time (while checking to see
1545        whether the group could match an empty string).
1547    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1548        [\P{Any}] did so. (Error in the code for printing property names.)
1550    21. An orphan \E inside a character class could cause a crash.
1552    22. A repeated capturing bracket such as (A)? could cause a wild memory
1553        reference during compilation.
1555    23. There are several functions in pcre_compile() that scan along a compiled
1556        expression for various reasons (e.g. to see if it's fixed length for look
1557        behind). There were bugs in these functions when a repeated \p or \P was
1558        present in the pattern. These operators have additional parameters compared
1559        with \d, etc, and these were not being taken into account when moving along
1560        the compiled data. Specifically:
1562        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1563            length.
1565        (b) An item such as \pL+ within a repeated group could cause crashes or
1566            loops.
1568        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1569            "reference to non-existent subpattern" error.
1571        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1573    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1574        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1576    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1578    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1579        character were causing crashes (broken optimization).
1581    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1582        \p or \P) caused a compile-time loop.
1584    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1585        break. For example, the unstudied pattern [\r\n]A does not match the string
1586        "\r\nA" because change 7.0/46 below moves the current point on by two
1587        characters after failing to match at the start. However, the pattern \nA
1588        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1589        the same is true. There doesn't seem any very clean way out of this, but
1590        what I have chosen to do makes the common cases work: PCRE now takes note
1591        of whether there can be an explicit match for \r or \n anywhere in the
1592        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1593        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1594        pattern has explicit CR or LF references.
1596    29. Added (*CR) etc for changing newline setting at start of pattern.
1599    Version 7.2 19-Jun-07
1600    ---------------------
1602     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1603        which is apparently normally available under Windows.
1605     2. Re-jig the pcregrep tests with different newline settings in an attempt
1606        to make them independent of the local environment's newline setting.
1608     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1610     4. Some of the "internals" tests were previously cut out when the link size
1611        was not 2, because the output contained actual offsets. The recent new
1612        "Z" feature of pcretest means that these can be cut out, making the tests
1613        usable with all link sizes.
1615     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1616        stack recursion. This gives a massive performance boost under BSD, but just
1617        a small improvement under Linux. However, it saves one field in the frame
1618        in all cases.
1620     6. Added more features from the forthcoming Perl 5.10:
1622        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1623            recursion call. It refers to the nth most recently opened parentheses.
1625        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1626            to be opened parentheses.
1628        (c) Conditions that refer to capturing parentheses can be specified
1629            relatively, for example, (?(-2)... or (?(+3)...
1631        (d) \K resets the start of the current match so that everything before
1632            is not part of it.
1634        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1636        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1637            reference syntax.
1639        (g) (?| introduces a group in which the numbering of parentheses in each
1640            alternative starts with the same number.
1642        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1644     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1647     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1648        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1649        for detecting groups that can match an empty string.
1651     9. A pattern with a very large number of alternatives (more than several
1652        hundred) was running out of internal workspace during the pre-compile
1653        phase, where pcre_compile() figures out how much memory will be needed. A
1654        bit of new cunning has reduced the workspace needed for groups with
1655        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1656        workspace instead of running out of the 4096 that are available.
1658    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1660    11. Applied patch from Google to remove an optimization that didn't quite work.
1661        The report of the bug said:
1663          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1664          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1665          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1667    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1668        it matched the wrong number of bytes.
1671    Version 7.1 24-Apr-07
1672    ---------------------
1674     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1675        that is more "standard", making use of automake and other Autotools. There
1676        is some re-arrangement of the files and adjustment of comments consequent
1677        on this.
1679     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1680        for recursive directory scanning broke on some systems because the files
1681        are not scanned in any specific order and on different systems the order
1682        was different. A call to "sort" has been inserted into RunGrepTest for the
1683        approprate test as a short-term fix. In the longer term there may be an
1684        alternative.
1686     3. I had an email from Eric Raymond about problems translating some of PCRE's
1687        man pages to HTML (despite the fact that I distribute HTML pages, some
1688        people do their own conversions for various reasons). The problems
1689        concerned the use of low-level troff macros .br and .in. I have therefore
1690        removed all such uses from the man pages (some were redundant, some could
1691        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1692        HTML has been updated to handle .nf/.fi and to complain if it encounters
1693        .br or .in.
1695     4. Updated comments in configure.ac that get placed in config.h.in and also
1696        arranged for config.h to be included in the distribution, with the name
1697        config.h.generic, for the benefit of those who have to compile without
1698        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1700     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1701        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1702        makevp.bat for the current PCRE, using the additional files
1703        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1705     6. A Windows user reported a minor discrepancy with test 2, which turned out
1706        to be caused by a trailing space on an input line that had got lost in his
1707        copy. The trailing space was an accident, so I've just removed it.
1709     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1710        that is needed.
1712     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1713        as "const" (a) because they are and (b) because it helps the PHP
1714        maintainers who have recently made a script to detect big data structures
1715        in the php code that should be moved to the .rodata section. I remembered
1716        to update Builducptable as well, so it won't revert if ucptable.h is ever
1717        re-created.
1719     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1720        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1721        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1722        support is not required. This saves 1.5-2K of code, which is important in
1723        some applications.
1725        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1726        so as not to refer to the tables, even though these functions will never be
1727        called when UTF-8 support is disabled. Otherwise there are problems with a
1728        shared library.
1730    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1732        (a) It was defining its arguments as char * instead of void *.
1734        (b) It was assuming that all moves were upwards in memory; this was true
1735            a long time ago when I wrote it, but is no longer the case.
1737        The emulated memove() is provided for those environments that have neither
1738        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1739        is clearly not the case, as these two bugs were recently reported.
1741    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1742        and Detrail to create the HTML documentation, the .txt form of the man
1743        pages, and it removes trailing spaces from listed files. It also creates
1744        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1745        case, it wraps all the #defines with #ifndefs. This script should be run
1746        before "make dist".
1748    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1749        with Unicode property support.
1751        (a) For a maximizing quantifier, if the two different cases of the
1752            character were of different lengths in their UTF-8 codings (there are
1753            some cases like this - I found 11), and the matching function had to
1754            back up over a mixture of the two cases, it incorrectly assumed they
1755            were both the same length.
1757        (b) When PCRE was configured to use the heap rather than the stack for
1758            recursion during matching, it was not correctly preserving the data for
1759            the other case of a UTF-8 character when checking ahead for a match
1760            while processing a minimizing repeat. If the check also involved
1761            matching a wide character, but failed, corruption could cause an
1762            erroneous result when trying to check for a repeat of the original
1763            character.
1765    13. Some tidying changes to the testing mechanism:
1767        (a) The RunTest script now detects the internal link size and whether there
1768            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1769            values substituted by "configure". (The RunGrepTest script already did
1770            this for UTF-8.) The configure.ac script no longer substitutes the
1771            relevant variables.
1773        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1774            with length and offset values. This means that the output is different
1775            for different internal link sizes. Test 2 is skipped for link sizes
1776            other than 2 because of this, bypassing the problem. Unfortunately,
1777            there was also a test in test 3 (the locale tests) that used /B and
1778            failed for link sizes other than 2. Rather than cut the whole test out,
1779            I have added a new /Z option to pcretest that replaces the length and
1780            offset values with spaces. This is now used to make test 3 independent
1781            of link size. (Test 2 will be tidied up later.)
1783    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1784        segmentation fault instead of returning the appropriate error message.
1786    15. In multiline mode when the newline sequence was set to "any", the pattern
1787        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1788        This doesn't seem right; it now treats the CRLF combination as the line
1789        ending, and so does not match in that case. It's only a pattern such as ^$
1790        that would hit this one: something like ^ABC$ would have failed after \r
1791        and then tried again after \r\n.
1793    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1794        in an attempt to make files that differ only in their line terminators
1795        compare equal. This works on Linux.
1797    17. Under certain error circumstances pcregrep might try to free random memory
1798        as it exited. This is now fixed, thanks to valgrind.
1800    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1801        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1802        was because its rules for how to advance for /g after matching an empty
1803        string at the end of a line did not allow for this case. They now check for
1804        it specially.
1806    20. pcretest is supposed to handle patterns and data of any length, by
1807        extending its buffers when necessary. It was getting this wrong when the
1808        buffer for a data line had to be extended.
1810    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1811        CRLF as a newline sequence.
1813    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1814        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1815        I have nevertheless tidied it up.
1817    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1819    24. Added a man page for pcre-config.
1822    Version 7.0 19-Dec-06
1823    ---------------------
1825     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1826        moving to gcc 4.1.1.
1828     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1829        sys/time.h, which is documented as needed for this function. It doesn't
1830        seem to matter on Linux, but it showed up on some releases of OS X.
1832     3. It seems that there are systems where bytes whose values are greater than
1833        127 match isprint() in the "C" locale. The "C" locale should be the
1834        default when a C program starts up. In most systems, only ASCII printing
1835        characters match isprint(). This difference caused the output from pcretest
1836        to vary, making some of the tests fail. I have changed pcretest so that:
1838        (a) When it is outputting text in the compiled version of a pattern, bytes
1839            other than 32-126 are always shown as hex escapes.
1841        (b) When it is outputting text that is a matched part of a subject string,
1842            it does the same, unless a different locale has been set for the match
1843            (using the /L modifier). In this case, it uses isprint() to decide.
1845     4. Fixed a major bug that caused incorrect computation of the amount of memory
1846        required for a compiled pattern when options that changed within the
1847        pattern affected the logic of the preliminary scan that determines the
1848        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1849        that the computed length was too small. The symptoms of this bug were
1850        either the PCRE error "internal error: code overflow" from pcre_compile(),
1851        or a glibc crash with a message such as "pcretest: free(): invalid next
1852        size (fast)". Examples of patterns that provoked this bug (shown in
1853        pcretest format) are:
1855          /(?-x: )/x
1856          /(?x)(?-x: \s*#\s*)/
1857          /((?i)[\x{c0}])/8
1858          /(?i:[\x{c0}])/8
1860        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1861        is now done differently.
1863     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1864        wrapper classes; (b) implement a new function in the C++ scanner that is
1865        more efficient than the old way of doing things because it avoids levels of
1866        recursion in the regex matching; (c) add a paragraph to the documentation
1867        for the FullMatch() function.
1869     6. The escape sequence \n was being treated as whatever was defined as
1870        "newline". Not only was this contrary to the documentation, which states
1871        that \n is character 10 (hex 0A), but it also went horribly wrong when
1872        "newline" was defined as CRLF. This has been fixed.
1874     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1875        was being set to -1 for the "end of line" case (supposedly a value that no
1876        character can have). Though this value is never used (the check for end of
1877        line is "zero bytes in current character"), it caused compiler complaints.
1878        I've changed it to 0xffffffff.
1880     8. In pcre_version.c, the version string was being built by a sequence of
1881        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1882        string (as it is for production releases) called a macro with an empty
1883        argument. The C standard says the result of this is undefined. The gcc
1884        compiler treats it as an empty string (which was what was wanted) but it is
1885        reported that Visual C gives an error. The source has been hacked around to
1886        avoid this problem.
1888     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1889        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1890        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1891        of them did).
1893    10. Originally, pcretest opened its input and output without "b"; then I was
1894        told that "b" was needed in some environments, so it was added for release
1895        5.0 to both the input and output. (It makes no difference on Unix-like
1896        systems.) Later I was told that it is wrong for the input on Windows. I've
1897        now abstracted the modes into two macros, to make it easier to fiddle with
1898        them, and removed "b" from the input mode under Windows.
1900    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1902    12. Added -help and --help to pcretest as an official way of being reminded
1903        of the options.
1905    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1906        and pcrecpp.cc because they annoy compilers at high warning levels.
1908    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1910    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1911        scripts are not C programs :-) and which was not noticed because it works
1912        on Linux.
1914    16. pcretest is supposed to handle any length of pattern and data line (as one
1915        line or as a continued sequence of lines) by extending its input buffer if
1916        necessary. This feature was broken for very long pattern lines, leading to
1917        a string of junk being passed to pcre_compile() if the pattern was longer
1918        than about 50K.
1920    17. I have done a major re-factoring of the way pcre_compile() computes the
1921        amount of memory needed for a compiled pattern. Previously, there was code
1922        that made a preliminary scan of the pattern in order to do this. That was
1923        OK when PCRE was new, but as the facilities have expanded, it has become
1924        harder and harder to keep it in step with the real compile phase, and there
1925        have been a number of bugs (see for example, 4 above). I have now found a
1926        cunning way of running the real compile function in a "fake" mode that
1927        enables it to compute how much memory it would need, while actually only
1928        ever using a few hundred bytes of working memory and without too many
1929        tests of the mode. This should make future maintenance and development
1930        easier. A side effect of this work is that the limit of 200 on the nesting
1931        depth of parentheses has been removed (though this was never a serious
1932        limitation, I suspect). However, there is a downside: pcre_compile() now
1933        runs more slowly than before (30% or more, depending on the pattern). I
1934        hope this isn't a big issue. There is no effect on runtime performance.
1936    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1937        newline (only possible for the last line of a file) and it was a
1938        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1940    19. Added additional timing features to pcretest. (1) The -tm option now times
1941        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1942        separate command line item, by a number that specifies the number of
1943        repeats to use when timing. The default is 50000; this gives better
1944        precision, but takes uncomfortably long for very large patterns.
1946    20. Extended pcre_study() to be more clever in cases where a branch of a
1947        subpattern has no definite first character. For example, (a*|b*)[cd] would
1948        previously give no result from pcre_study(). Now it recognizes that the
1949        first character must be a, b, c, or d.
1951    21. There was an incorrect error "recursive call could loop indefinitely" if
1952        a subpattern (or the entire pattern) that was being tested for matching an
1953        empty string contained only one non-empty item after a nested subpattern.
1954        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1955        incorrectly, because the \d was being skipped in the check.
1957    22. The pcretest program now has a new pattern option /B and a command line
1958        option -b, which is equivalent to adding /B to every pattern. This causes
1959        it to show the compiled bytecode, without the additional information that
1960        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1961        is the same as /B/I).
1963    23. A new optimization is now able automatically to treat some sequences such
1964        as a*b as a*+b. More specifically, if something simple (such as a character
1965        or a simple class like \d) has an unlimited quantifier, and is followed by
1966        something that cannot possibly match the quantified thing, the quantifier
1967        is automatically "possessified".
1969    24. A recursive reference to a subpattern whose number was greater than 39
1970        went wrong under certain circumstances in UTF-8 mode. This bug could also
1971        have affected the operation of pcre_study().
1973    25. Realized that a little bit of performance could be had by replacing
1974        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1976    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1978    27. Possessive quantifiers such as a++ were previously implemented by turning
1979        them into atomic groups such as ($>a+). Now they have their own opcodes,
1980        which improves performance. This includes the automatically created ones
1981        from 23 above.
1983    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1984        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1985        the first matched character to be a colon. This applied both to named and
1986        numbered groups.
1988    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1990    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1991        building PCRE on Windows easier, so I have included it in the distribution.
1993    31. There is now a check in pcretest against a ridiculously large number being
1994        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1995        loop, the loop is abandoned.
1997    32. Forward references to subpatterns in conditions such as (?(2)...) where
1998        subpattern 2 is defined later cause pcre_compile() to search forwards in
1999        the pattern for the relevant set of parentheses. This search went wrong
2000        when there were unescaped parentheses in a character class, parentheses
2001        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2003    33. "Subroutine" calls and backreferences were previously restricted to
2004        referencing subpatterns earlier in the regex. This restriction has now
2005        been removed.
2007    34. Added a number of extra features that are going to be in Perl 5.10. On the
2008        whole, these are just syntactic alternatives for features that PCRE had
2009        previously implemented using the Python syntax or my own invention. The
2010        other formats are all retained for compatibility.
2012        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2013            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2014            also .NET compatible.
2016        (b) A recursion or subroutine call to a named group can now be defined as
2017            (?&name) as well as (?P>name).
2019        (c) A backreference to a named group can now be defined as \k<name> or
2020            \k'name' as well as (?P=name). The new forms, as well as being in Perl
2021            5.10, are also .NET compatible.
2023        (d) A conditional reference to a named group can now use the syntax
2024            (?(<name>) or (?('name') as well as (?(name).
2026        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2027            groups (named and numbered) that are never evaluated inline, but can be
2028            called as "subroutines" from elsewhere. In effect, the DEFINE condition
2029            is always false. There may be only one alternative in such a group.
2031        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2032            as the simple (?(R). The condition is true only if the most recent
2033            recursion is that of the given number or name. It does not search out
2034            through the entire recursion stack.
2036        (g) The escape \gN or \g{N} has been added, where N is a positive or
2037            negative number, specifying an absolute or relative reference.
2039    35. Tidied to get rid of some further signed/unsigned compiler warnings and
2040        some "unreachable code" warnings.
2042    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2043        things, this adds five new scripts.
2045    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2046        There were also incompatibilities regarding the handling of \Q..\E inside
2047        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2048        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2050    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2051        matches an empty string, and forcibly breaks the loop. There were bugs in
2052        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
2053        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
2054        separate and independent bugs (that affected different cases) have been
2055        fixed.
2057    39. Refactored the code to abolish the use of different opcodes for small
2058        capturing bracket numbers. This is a tidy that I avoided doing when I
2059        removed the limit on the number of capturing brackets for 3.5 back in 2001.
2060        The new approach is not only tidier, it makes it possible to reduce the
2061        memory needed to fix the previous bug (38).
2063    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2064        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2065        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2066        mode.
2068    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2069        report.
2071    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2072        copy construction and assignment in the C++ wrapper.
2074    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2075        couple of bugs that could have given wrong results in the "--newline=crlf"
2076        case.
2078    44. Added a number of casts and did some reorganization of signed/unsigned int
2079        variables following suggestions from Dair Grant. Also renamed the variable
2080        "this" as "item" because it is a C++ keyword.
2082    45. Arranged for dftables to add
2084          #include "pcre_internal.h"
2086        to pcre_chartables.c because without it, gcc 4.x may remove the array
2087        definition from the final binary if PCRE is built into a static library and
2088        dead code stripping is activated.
2090    46. For an unanchored pattern, if a match attempt fails at the start of a
2091        newline sequence, and the newline setting is CRLF or ANY, and the next two
2092        characters are CRLF, advance by two characters instead of one.
2095    Version 6.7 04-Jul-06
2096    ---------------------
2098     1. In order to handle tests when input lines are enormously long, pcretest has
2099        been re-factored so that it automatically extends its buffers when
2100        necessary. The code is crude, but this _is_ just a test program. The
2101        default size has been increased from 32K to 50K.
2103     2. The code in pcre_study() was using the value of the re argument before
2104        testing it for NULL. (Of course, in any sensible call of the function, it
2105        won't be NULL.)
2107     3. The memmove() emulation function in pcre_internal.h, which is used on
2108        systems that lack both memmove() and bcopy() - that is, hardly ever -
2109        was missing a "static" storage class specifier.
2111     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2112        containing an extended class (one that cannot be represented by a bitmap
2113        because it contains high-valued characters or Unicode property items, e.g.
2114        [\pZ]). Almost always one would set UTF-8 mode when processing such a
2115        pattern, but PCRE should not loop if you do not (it no longer does).
2116        [Detail: two cases were found: (a) a repeated subpattern containing an
2117        extended class; (b) a recursive reference to a subpattern that followed a
2118        previous extended class. It wasn't skipping over the extended class
2119        correctly when UTF-8 mode was not set.]
2121     5. A negated single-character class was not being recognized as fixed-length
2122        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2123        compile error "lookbehind assertion is not fixed length".
2125     6. The RunPerlTest auxiliary script was showing an unexpected difference
2126        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2127        write a Perl script that can interpret lines of an input file either as
2128        byte characters or as UTF-8, which is what "perltest" was being required to
2129        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2130        can't do is switch easily at run time between having the "use utf8;" pragma
2131        or not. In the end, I fudged it by using the RunPerlTest script to insert
2132        "use utf8;" explicitly for the UTF-8 tests.
2134     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2135        the end of the subject string, contrary to the documentation and to what
2136        Perl does. This was true of both matching functions. Now it matches only at
2137        the start of the subject and immediately after *internal* newlines.
2139     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2140        a pointer to an int instead of a pointer to an unsigned long int. This
2141        caused problems on 64-bit systems.
2143     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2144        instance of the 'standard' template library not being so standard".
2146    10. There was no check on the number of named subpatterns nor the maximum
2147        length of a subpattern name. The product of these values is used to compute
2148        the size of the memory block for a compiled pattern. By supplying a very
2149        long subpattern name and a large number of named subpatterns, the size
2150        computation could be caused to overflow. This is now prevented by limiting
2151        the length of names to 32 characters, and the number of named subpatterns
2152        to 10,000.
2154    11. Subpatterns that are repeated with specific counts have to be replicated in
2155        the compiled pattern. The size of memory for this was computed from the
2156        length of the subpattern and the repeat count. The latter is limited to
2157        65535, but there was no limit on the former, meaning that integer overflow
2158        could in principle occur. The compiled length of a repeated subpattern is
2159        now limited to 30,000 bytes in order to prevent this.
2161    12. Added the optional facility to have named substrings with the same name.
2163    13. Added the ability to use a named substring as a condition, using the
2164        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2165        are numbers (not recommended). Forward references are permitted.
2167    14. Added forward references in named backreferences (if you see what I mean).
2169    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2170        pattern could run off the end of the subject. For example, the pattern
2171        "(?s)(.{1,5})"8 did this with the subject "ab".
2173    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2174        PCRE_CASELESS was set when matching characters that were quantified with ?
2175        or *.
2177    17. A character class other than a single negated character that had a minimum
2178        but no maximum quantifier - for example [ab]{6,} - was not handled
2179        correctly by pce_dfa_exec(). It would match only one character.
2181    18. A valid (though odd) pattern that looked like a POSIX character
2182        class but used an invalid character after [ (for example [[,abc,]]) caused
2183        pcre_compile() to give the error "Failed: internal error: code overflow" or
2184        in some cases to crash with a glibc free() error. This could even happen if
2185        the pattern terminated after [[ but there just happened to be a sequence of
2186        letters, a binary zero, and a closing ] in the memory that followed.
2188    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2189        over the years. Originally (before any Unicode support), just the bottom 8
2190        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2191        output from "man perlunicode" includes this:
2193          The regular expression compiler produces polymorphic opcodes.  That
2194          is, the pattern adapts to the data and automatically switches to
2195          the Unicode character scheme when presented with Unicode data--or
2196          instead uses a traditional byte scheme when presented with byte
2197          data.
2199        Sadly, a wide octal escape does not cause a switch, and in a string with
2200        no other multibyte characters, these octal escapes are treated as before.
2201        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
2202        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2203        Unicode string.
2205        I have not perpetrated such confusion in PCRE. Up till now, it took just
2206        the bottom 8 bits, as in old Perl. I have now made octal escapes with
2207        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2208        translate to the appropriate multibyte character.
2210    29. Applied some refactoring to reduce the number of warnings from Microsoft
2211        and Borland compilers. This has included removing the fudge introduced
2212        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2213        a warning about an unused variable.
2215    21. PCRE has not included VT (character 0x0b) in the set of whitespace
2216        characters since release 4.0, because Perl (from release 5.004) does not.
2217        [Or at least, is documented not to: some releases seem to be in conflict
2218        with the documentation.] However, when a pattern was studied with
2219        pcre_study() and all its branches started with \s, PCRE still included VT
2220        as a possible starting character. Of course, this did no harm; it just
2221        caused an unnecessary match attempt.
2223    22. Removed a now-redundant internal flag bit that recorded the fact that case
2224        dependency changed within the pattern. This was once needed for "required
2225        byte" processing, but is no longer used. This recovers a now-scarce options
2226        bit. Also moved the least significant internal flag bit to the most-
2227        significant bit of the word, which was not previously used (hangover from
2228        the days when it was an int rather than a uint) to free up another bit for
2229        the future.
2231    23. Added support for CRLF line endings as well as CR and LF. As well as the
2232        default being selectable at build time, it can now be changed at runtime
2233        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2234        specify that it is scanning data with non-default line endings.
2236    24. Changed the definition of CXXLINK to make it agree with the definition of
2237        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2239    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2240        recursions. This makes a big different to stack usage for some patterns.
2242    26. If a subpattern containing a named recursion or subroutine reference such
2243        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2244        the space required for the compiled pattern went wrong and gave too small a
2245        value. Depending on the environment, this could lead to "Failed: internal
2246        error: code overflow at offset 49" or "glibc detected double free or
2247        corruption" errors.
2249    27. Applied patches from Google (a) to support the new newline modes and (b) to
2250        advance over multibyte UTF-8 characters in GlobalReplace.
2252    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2253        difference for some implementation of PCRE in some Windows version.
2255    29. Added some extra testing facilities to pcretest:
2257        \q<number>   in a data line sets the "match limit" value
2258        \Q<number>   in a data line sets the "match recursion limt" value
2259        -S <number>  sets the stack size, where <number> is in megabytes
2261        The -S option isn't available for Windows.
2264    Version 6.6 06-Feb-06
2265    ---------------------
2267     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2268        in pcreposix.h. I have copied the definition from pcre.h.
2270     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2271        because pcre.h is no longer a built file.
2273     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2274        not normally included in the compiled code.
2277    Version 6.5 01-Feb-06
2278    ---------------------
2280     1. When using the partial match feature with pcre_dfa_exec(), it was not
2281        anchoring the second and subsequent partial matches at the new starting
2282        point. This could lead to incorrect results. For example, with the pattern
2283        /1234/, partially matching against "123" and then "a4" gave a match.
2285     2. Changes to pcregrep:
2287        (a) All non-match returns from pcre_exec() were being treated as failures
2288            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2289            error message is output. Some extra information is given for the
2290            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2291            probably the only errors that are likely to be caused by users (by
2292            specifying a regex that has nested indefinite repeats, for instance).
2293            If there are more than 20 of these errors, pcregrep is abandoned.
2295        (b) A binary zero was treated as data while matching, but terminated the
2296            output line if it was written out. This has been fixed: binary zeroes
2297            are now no different to any other data bytes.
2299        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2300            used to set a locale for matching. The --locale=xxxx long option has
2301            been added (no short equivalent) to specify a locale explicitly on the
2302            pcregrep command, overriding the environment variables.
2304        (d) When -B was used with -n, some line numbers in the output were one less
2305            than they should have been.
2307        (e) Added the -o (--only-matching) option.
2309        (f) If -A or -C was used with -c (count only), some lines of context were
2310            accidentally printed for the final match.
2312        (g) Added the -H (--with-filename) option.
2314        (h) The combination of options -rh failed to suppress file names for files
2315            that were found from directory arguments.
2317        (i) Added the -D (--devices) and -d (--directories) options.
2319        (j) Added the -F (--fixed-strings) option.
2321        (k) Allow "-" to be used as a file name for -f as well as for a data file.
2323        (l) Added the --colo(u)r option.
2325        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2326            is not present by default.
2328     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2329        items such as (?R) or (?1), when the recursion could match a number of
2330        alternatives. If it matched one of the alternatives, but subsequently,
2331        outside the recursion, there was a failure, the code tried to back up into
2332        the recursion. However, because of the way PCRE is implemented, this is not
2333        possible, and the result was an incorrect result from the match.
2335        In order to prevent this happening, the specification of recursion has
2336        been changed so that all such subpatterns are automatically treated as
2337        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2339     4. I had overlooked the fact that, in some locales, there are characters for
2340        which isalpha() is true but neither isupper() nor islower() are true. In
2341        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2342        and ordfeminine) are like this. This affected the treatment of \w and \W
2343        when they appeared in character classes, but not when they appeared outside
2344        a character class. The bit map for "word" characters is now created
2345        separately from the results of isalnum() instead of just taking it from the
2346        upper, lower, and digit maps. (Plus the underscore character, of course.)
2348     5. The above bug also affected the handling of POSIX character classes such as
2349        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2350        permanent tables. Instead, the bit maps for such a class were previously
2351        created as the appropriate unions of the upper, lower, and digit bitmaps.
2352        Now they are created by subtraction from the [[:word:]] class, which has
2353        its own bitmap.
2355     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2356        It is created by subtracting the vertical space characters (\x09, \x0a,
2357        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2358        subtraction was done in the overall bitmap for a character class, meaning
2359        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2360        be recognized. This bug has been fixed.
2362     7. Patches from the folks at Google:
2364          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2365          real life, but is still worth protecting against".
2367          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2368          regular expressions".
2370          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2371          have it.
2373          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2374          "configure" and the latter not, in order to fix a problem somebody had
2375          with compiling the Arg class on HP-UX.
2377          (e) Improve the error-handling of the C++ wrapper a little bit.
2379          (f) New tests for checking recursion limiting.
2381     8. The pcre_memmove() function, which is used only if the environment does not
2382        have a standard memmove() function (and is therefore rarely compiled),
2383        contained two bugs: (a) use of int instead of size_t, and (b) it was not
2384        returning a result (though PCRE never actually uses the result).
2386     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2387        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2388        returned instead of calling malloc() with an overflowing number that would
2389        most likely cause subsequent chaos.
2391    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2393    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2394        with this option is matched, the nmatch and pmatch options of regexec() are
2395        ignored.
2397    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2398        provided in case anyone wants to the the POSIX interface with UTF-8
2399        strings.
2401    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2402        C++ linking (needed for some HP-UX environments).
2404    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2405        (unused parameter) and in the pcre_printint() function (omitted "default"
2406        switch label when the default is to do nothing).
2408    15. Added some code to make it possible, when PCRE is compiled as a C++
2409        library, to replace subject pointers for pcre_exec() with a smart pointer
2410        class, thus making it possible to process discontinuous strings.
2412    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2413        much the same function. They were added by different people who were trying
2414        to make PCRE easy to compile on non-Unix systems. It has been suggested
2415        that PCRE_EXPORT be abolished now that there is more automatic apparatus
2416        for compiling on Windows systems. I have therefore replaced it with
2417        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2418        defaults to "extern" for C or "extern C" for C++, which works fine on
2419        Unix-like systems. It is now possible to override the value of PCRE_DATA_
2420        SCOPE with something explicit in config.h. In addition:
2422        (a) pcreposix.h still had just "extern" instead of either of these macros;
2423            I have replaced it with PCRE_DATA_SCOPE.
2425        (b) Functions such as _pcre_xclass(), which are internal to the library,
2426            but external in the C sense, all had PCRE_EXPORT in their definitions.
2427            This is apparently wrong for the Windows case, so I have removed it.
2428            (It makes no difference on Unix-like systems.)
2430    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2431        of recursive calls to match(). This is different to MATCH_LIMIT because
2432        that limits the total number of calls to match(), not all of which increase
2433        the depth of recursion. Limiting the recursion depth limits the amount of
2434        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2435        when PCRE is compiled, and changed at run time. A patch from Google adds
2436        this functionality to the C++ interface.
2438    18. Changes to the handling of Unicode character properties:
2440        (a) Updated the table to Unicode 4.1.0.
2442        (b) Recognize characters that are not in the table as "Cn" (undefined).
2444        (c) I revised the way the table is implemented to a much improved format
2445            which includes recognition of ranges. It now supports the ranges that
2446            are defined in UnicodeData.txt, and it also amalgamates other
2447            characters into ranges. This has reduced the number of entries in the
2448            table from around 16,000 to around 3,000, thus reducing its size
2449            considerably. I realized I did not need to use a tree structure after
2450            all - a binary chop search is just as efficient. Having reduced the
2451            number of entries, I extended their size from 6 bytes to 8 bytes to
2452            allow for more data.
2454        (d) Added support for Unicode script names via properties such as \p{Han}.
2456    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2457        matching that character.
2459    20. When matching a repeated Unicode property with a minimum greater than zero,
2460        (for example \pL{2,}), PCRE could look past the end of the subject if it
2461        reached it while seeking the minimum number of characters. This could
2462        happen only if some of the characters were more than one byte long, because
2463        there is a check for at least the minimum number of bytes.
2465    21. Refactored the implementation of \p and \P so as to be more general, to
2466        allow for more different types of property in future. This has changed the
2467        compiled form incompatibly. Anybody with saved compiled patterns that use
2468        \p or \P will have to recompile them.
2470    22. Added "Any" and "L&" to the supported property types.
2472    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2473        but give a compile time error if the value is greater than 0xff.
2475    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2476        accidentally not being installed or uninstalled.
2478    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2479        made were to insert the current release number. This seemed silly, because
2480        it made things harder for people building PCRE on systems that don't run
2481        "configure". I have turned pcre.h into a distributed file, no longer built
2482        by "configure", with the version identification directly included. There is
2483        no longer a pcre.h.in file.
2485        However, this change necessitated a change to the pcre-config script as
2486        well. It is built from pcre-config.in, and one of the substitutions was the
2487        release number. I have updated configure.ac so that ./configure now finds
2488        the release number by grepping pcre.h.
2490    26. Added the ability to run the tests under valgrind.
2493    Version 6.4 05-Sep-05
2494    ---------------------
2496     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2497        "--" to be printed when multiple files were scanned, even when none of the
2498        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2499        consider it to be a bug, and have restored the previous behaviour.
2501     2. A couple of code tidies to get rid of compiler warnings.
2503     3. The pcretest program used to cheat by referring to symbols in the library
2504        whose names begin with _pcre_. These are internal symbols that are not
2505        really supposed to be visible externally, and in some environments it is
2506        possible to suppress them. The cheating is now confined to including
2507        certain files from the library's source, which is a bit cleaner.
2509     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2510        file's purpose clearer.
2512     5. Reorganized pcre_ucp_findchar().
2515    Version 6.3 15-Aug-05
2516    ---------------------
2518     1. The file libpcre.pc.in did not have general read permission in the tarball.
2520     2. There were some problems when building without C++ support:
2522        (a) If C++ support was not built, "make install" and "make test" still
2523            tried to test it.
2525        (b) There were problems when the value of CXX was explicitly set. Some
2526            changes have been made to try to fix these, and ...
2528        (c) --disable-cpp can now be used to explicitly disable C++ support.
2530        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2531            backslash in a target when C++ was disabled. This confuses some
2532            versions of "make", apparently. Using an intermediate variable solves
2533            this. (Same for CPP_LOBJ.)
2535     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2536        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2537        necessary on certain architectures.
2539     4. Added a setting of -export-symbols-regex to the link command to remove
2540        those symbols that are exported in the C sense, but actually are local
2541        within the library, and not documented. Their names all begin with
2542        "_pcre_". This is not a perfect job, because (a) we have to except some
2543        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2544        available (and never for static libraries). I have made a note to try to
2545        find a way round (a) in the future.
2548    Version 6.2 01-Aug-05
2549    ---------------------
2551     1. There was no test for integer overflow of quantifier values. A construction
2552        such as {1111111111111111} would give undefined results. What is worse, if
2553        a minimum quantifier for a parenthesized subpattern overflowed and became
2554        negative, the calculation of the memory size went wrong. This could have
2555        led to memory overwriting.
2557     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2559     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2560        operating environments where this matters.
2562     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2563        PCRE options from within the C++ wrapper.
2565     5. Named capturing subpatterns were not being correctly counted when a pattern
2566        was compiled. This caused two problems: (a) If there were more than 100
2567        such subpatterns, the calculation of the memory needed for the whole
2568        compiled pattern went wrong, leading to an overflow error. (b) Numerical
2569        back references of the form \12, where the number was greater than 9, were
2570        not recognized as back references, even though there were sufficient
2571        previous subpatterns.
2573     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2574        versions of gcc, e.g. 2.95.4.
2577    Version 6.1 21-Jun-05
2578    ---------------------
2580     1. There was one reference to the variable "posix" in pcretest.c that was not
2581        surrounded by "#if !defined NOPOSIX".
2583     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2584        the cross-check on the old pcre_info() function, for the benefit of the
2585        cut-down version of PCRE that is currently imported into Exim.
2587     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2588        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2589        patterns that start (?i) but I don't think that matters. The use of (?i) is
2590        just an example; this all applies to the other options as well.
2592     4. Since libtool seems to echo the compile commands it is issuing, the output
2593        from "make" can be reduced a bit by putting "@" in front of each libtool
2594        compile command.
2596     5. Patch from the folks at Google for configure.in to be a bit more thorough
2597        in checking for a suitable C++ installation before trying to compile the
2598        C++ stuff. This should fix a reported problem when a compiler was present,
2599        but no suitable headers.
2601     6. The man pages all had just "PCRE" as their title. I have changed them to
2602        be the relevant file name. I have also arranged that these names are
2603        retained in the file doc/pcre.txt, which is a concatenation in text format
2604        of all the man pages except the little individual ones for each function.
2606     7. The NON-UNIX-USE file had not been updated for the different set of source
2607        files that come with release 6. I also added a few comments about the C++
2608        wrapper.
2611    Version 6.0 07-Jun-05
2612    ---------------------
2614     1. Some minor internal re-organization to help with my DFA experiments.
2616     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2617        didn't matter for the library itself when fully configured, but did matter
2618        when compiling without UCP support, or within Exim, where the ucp files are
2619        not imported.
2621     3. Refactoring of the library code to split up the various functions into
2622        different source modules. The addition of the new DFA matching code (see
2623        below) to a single monolithic source would have made it really too
2624        unwieldy, quite apart from causing all the code to be include in a
2625        statically linked application, when only some functions are used. This is
2626        relevant even without the DFA addition now that patterns can be compiled in
2627        one application and matched in another.
2629        The downside of splitting up is that there have to be some external
2630        functions and data tables that are used internally in different modules of
2631        the library but which are not part of the API. These have all had their
2632        names changed to start with "_pcre_" so that they are unlikely to clash
2633        with other external names.
2635     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2636        a different (DFA) algorithm. Although it is slower than the original
2637        function, it does have some advantages for certain types of matching
2638        problem.
2640     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2641        including restarting after a partial match.
2643     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2644        defined when compiling for Windows was sent to me. I have put it into the
2645        code, though I have no means of testing or verifying it.
2647     7. Added the pcre_refcount() auxiliary function.
2649     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2650        match before or at the first newline in the subject string. In pcretest,
2651        the /f option on a pattern can be used to set this.
2653     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2654        would behave wrongly. This has been present in PCRE since release 4.0.
2656    10. A number of changes to the pcregrep command:
2658        (a) Refactored how -x works; insert ^(...)$ instead of setting
2659            PCRE_ANCHORED and checking the length, in preparation for adding
2660            something similar for -w.
2662        (b) Added the -w (match as a word) option.
2664        (c) Refactored the way lines are read and buffered so as to have more
2665            than one at a time available.
2667        (d) Implemented a pcregrep test script.
2669        (e) Added the -M (multiline match) option. This allows patterns to match
2670            over several lines of the subject. The buffering ensures that at least
2671            8K, or the rest of the document (whichever is the shorter) is available
2672            for matching (and similarly the previous 8K for lookbehind assertions).
2674        (f) Changed the --help output so that it now says
2676              -w, --word-regex(p)
2678            instead of two lines, one with "regex" and the other with "regexp"
2679            because that confused at least one person since the short forms are the
2680            same. (This required a bit of code, as the output is generated
2681            automatically from a table. It wasn't just a text change.)
2683        (g) -- can be used to terminate pcregrep options if the next thing isn't an
2684            option but starts with a hyphen. Could be a pattern or a path name
2685            starting with a hyphen, for instance.
2687        (h) "-" can be given as a file name to represent stdin.
2689        (i) When file names are being printed, "(standard input)" is used for
2690            the standard input, for compatibility with GNU grep. Previously
2691            "<stdin>" was used.
2693        (j) The option --label=xxx can be used to supply a name to be used for
2694            stdin when file names are being printed. There is no short form.
2696        (k) Re-factored the options decoding logic because we are going to add
2697            two more options that take data. Such options can now be given in four
2698            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2700        (l) Added the -A, -B, and -C options for requesting that lines of context
2701            around matches be printed.
2703        (m) Added the -L option to print the names of files that do not contain
2704            any matching lines, that is, the complement of -l.
2706        (n) The return code is 2 if any file cannot be opened, but pcregrep does
2707            continue to scan other files.
2709        (o) The -s option was incorrectly implemented. For compatibility with other
2710            greps, it now suppresses the error message for a non-existent or non-
2711            accessible file (but not the return code). There is a new option called
2712            -q that suppresses the output of matching lines, which was what -s was
2713            previously doing.
2715        (p) Added --include and --exclude options to specify files for inclusion
2716            and exclusion when recursing.
2718    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2719        Hopefully, it now does.
2721    12. Missing cast in pcre_study().
2723    13. Added an "uninstall" target to the makefile.
2725    14. Replaced "extern" in the function prototypes in Makefile.in with
2726        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2727        world, but is set differently for Windows.
2729    15. Added a second compiling function called pcre_compile2(). The only
2730        difference is that it has an extra argument, which is a pointer to an
2731        integer error code. When there is a compile-time failure, this is set
2732        non-zero, in addition to the error test pointer being set to point to an
2733        error message. The new argument may be NULL if no error number is required
2734        (but then you may as well call pcre_compile(), which is now just a
2735        wrapper). This facility is provided because some applications need a
2736        numeric error indication, but it has also enabled me to tidy up the way
2737        compile-time errors are handled in the POSIX wrapper.
2739    16. Added VPATH=.libs to the makefile; this should help when building with one
2740        prefix path and installing with another. (Or so I'm told by someone who
2741        knows more about this stuff than I do.)
2743    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2744        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2745        match everything, including newlines. This is not POSIX-compatible, but
2746        somebody wanted the feature. From pcretest it can be activated by using
2747        both the P and the s flags.
2749    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2751    19. libpcre.pc was being incorrectly installed as executable.
2753    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2754        it now also looks for '\r' so that it will work unmodified on Windows.
2756    21. Added Google's contributed C++ wrapper to the distribution.
2758    22. Added some untidy missing memory free() calls in pcretest, to keep
2759        Electric Fence happy when testing.
2763    Version 5.0 13-Sep-04
2764    ---------------------
2766     1. Internal change: literal characters are no longer packed up into items
2767        containing multiple characters in a single byte-string. Each character
2768        is now matched using a separate opcode. However, there may be more than one
2769        byte in the character in UTF-8 mode.
2771     2. The pcre_callout_block structure has two new fields: pattern_position and
2772        next_item_length. These contain the offset in the pattern to the next match
2773        item, and its length, respectively.
2775     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2776        insertion of callouts before each pattern item. Added the /C option to
2777        pcretest to make use of this.
2779     4. On the advice of a Windows user, the lines
2781          #if defined(_WIN32) || defined(WIN32)
2782          _setmode( _fileno( stdout ), 0x8000 );
2783          #endif  /* defined(_WIN32) || defined(WIN32) */
2785        have been added to the source of pcretest. This apparently does useful
2786        magic in relation to line terminators.
2788     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2789        for the benefit of those environments where the "b" makes a difference.
2791     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2792        to know about it. I have put a hack into configure.in that adds in code
2793        to set GCC=yes if CC=icc. This seems to end up at a point in the
2794        generated configure script that is early enough to affect the setting of
2795        compiler options, which is what is needed, but I have no means of testing
2796        whether it really works. (The user who reported this had patched the
2797        generated configure script, which of course I cannot do.)
2799        LATER: After change 22 below (new libtool files), the configure script
2800        seems to know about icc (and also ecc). Therefore, I have commented out
2801        this hack in configure.in.
2803     7. Added support for pkg-config (2 patches were sent in).
2805     8. Negated POSIX character classes that used a combination of internal tables
2806        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2807        [[:^ascii]]. Typically, they would match almost any characters. The other
2808        POSIX classes were not broken in this way.
2810     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2811        to find the match, as PCRE was deluded into thinking that the match had to
2812        start at the start point or following a newline. The same bug applied to
2813        patterns with negative forward assertions or any backward assertions
2814        preceding ".*" at the start, unless the pattern required a fixed first
2815        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2817    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2818        starting at the last subject character, bytes beyond the end of the subject
2819        string were read.
2821    11. Renamed the variable "class" as "classbits" to make life easier for C++
2822        users. (Previously there was a macro definition, but it apparently wasn't
2823        enough.)
2825    12. Added the new field "tables" to the extra data so that tables can be passed
2826        in at exec time, or the internal tables can be re-selected. This allows
2827        a compiled regex to be saved and re-used at a later time by a different
2828        program that might have everything at different addresses.
2830    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2831        -R library as well as a -L library.
2833    14. The debugging options of pcretest (-d on the command line or D on a
2834        pattern) showed incorrect output for anything following an extended class
2835        that contained multibyte characters and which was followed by a quantifier.
2837    15. Added optional support for general category Unicode character properties
2838        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2839        support. It adds about 90K to the size of the library. The meanings of the
2840        inbuilt class escapes such as \d and \s have NOT been changed.
2842    16. Updated pcredemo.c to include calls to free() to release the memory for the
2843        compiled pattern.
2845    17. The generated file chartables.c was being created in the source directory
2846        instead of in the building directory. This caused the build to fail if the
2847        source directory was different from the building directory, and was
2848        read-only.
2850    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2851        file. No doubt somebody will tell me if they don't make sense... Also added
2852        Dan Mooney's comments about building on OpenVMS.
2854    19. Added support for partial matching via the PCRE_PARTIAL option for
2855        pcre_exec() and the \P data escape in pcretest.
2857    20. Extended pcretest with 3 new pattern features:
2859        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2860              write the compiled pattern to the file whose name is "rest-of-line".
2861              This is a straight binary dump of the data, with the saved pointer to
2862              the character tables forced to be NULL. The study data, if any, is
2863              written too. After writing, pcretest reads a new pattern.
2865        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2866              compiled pattern from the given file. There must not be any
2867              occurrences of "<" in the file name (pretty unlikely); if there are,
2868              pcretest will instead treat the initial "<" as a pattern delimiter.
2869              After reading in the pattern, pcretest goes on to read data lines as
2870              usual.
2872        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2873              and 16-bit fields in a compiled pattern, to simulate a pattern that
2874              was compiled on a host of opposite endianness.
2876    21. The pcre-exec() function can now cope with patterns that were compiled on
2877        hosts of opposite endianness, with this restriction:
2879          As for any compiled expression that is saved and used later, the tables
2880          pointer field cannot be preserved; the extra_data field in the arguments
2881          to pcre_exec() should be used to pass in a tables address if a value
2882          other than the default internal tables were used at compile time.
2884    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2885        now diagnosed as an error. Previously, most of the time, a negative number
2886        would have been treated as zero, but if in addition "ovector" was passed as
2887        NULL, a crash could occur.
2889    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2890        new versions from the libtool 1.5 distribution (the last one is a copy of
2891        a file called libtool.m4). This seems to have fixed the need to patch
2892        "configure" to support Darwin 1.3 (which I used to do). However, I still
2893        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2894        workstation).
2896    24. Changed the PCRE licence to be the more standard "BSD" licence.
2899    Version 4.5 01-Dec-03
2900    ---------------------
2902     1. There has been some re-arrangement of the code for the match() function so
2903        that it can be compiled in a version that does not call itself recursively.
2904        Instead, it keeps those local variables that need separate instances for
2905        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2906        needs to "recurse". Keeping track of where control must go is done by means
2907        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2908        hide most of the details from the main code, and operates only if
2909        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2910        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2911        operating.
2913        To make it easier for callers to provide specially tailored get/free
2914        functions for this usage, two new functions, pcre_stack_malloc, and
2915        pcre_stack_free, are used. They are always called in strict stacking order,
2916        and the size of block requested is always the same.
2918        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2919        PCRE has been compiled to use the stack or the heap for recursion. The
2920        -C option of pcretest uses this to show which version is compiled.
2922        A new data escape \S, is added to pcretest; it causes the amounts of store
2923        obtained and freed by both kinds of malloc/free at match time to be added
2924        to the output.
2926     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2927        what's available on my current Linux desktop machine.
2929     3. When matching a UTF-8 string, the test for a valid string at the start has
2930        been extended. If start_offset is not zero, PCRE now checks that it points
2931        to a byte that is the start of a UTF-8 character. If not, it returns
2932        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2933        this is necessary because there may be backward assertions in the pattern.
2934        When matching the same subject several times, it may save resources to use
2935        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2937     4. The code for checking the validity of UTF-8 strings has been tightened so
2938        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2939        containing "overlong sequences".
2941     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2942        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2943        should have been "&", but it just so happened that all the cases this let
2944        through by mistake were picked up later in the function.
2946     6. I had used a variable called "isblank" - this is a C99 function, causing
2947        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2949     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2950        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2951        so the version is shown; (c) stop "make test" echoing "./RunTest".
2953     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2955     9. The prototype for memmove() for systems that don't have it was using
2956        size_t, but the inclusion of the header that defines size_t was later. I've
2957        moved the #includes for the C headers earlier to avoid this.
2959    10. Added some adjustments to the code to make it easier to compiler on certain
2960        special systems:
2962          (a) Some "const" qualifiers were missing.
2963          (b) Added the macro EXPORT before all exported functions; by default this
2964              is defined to be empty.
2965          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2966              that it reads its output file name as an argument instead of writing
2967              to the standard output and assuming this can be redirected.
2969    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2970        class containing characters with values greater than 255, PCRE compilation
2971        went into a loop.
2973    12. A recursive reference to a subpattern that was within another subpattern
2974        that had a minimum quantifier of zero caused PCRE to crash. For example,
2975        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2976        recursion. If the recursively-called subpattern itself had a zero repeat,
2977        that was OK.
2979    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2980        buffer into which it was copied (for escape processing) was still set at
2981        1024, so long lines caused crashes.
2983    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2984        "internal error: code overflow...". This applied to any character class
2985        that was followed by a possessive quantifier.
2987    15. Modified the Makefile to add libpcre.la as a prerequisite for
2988        libpcreposix.la because I was told this is needed for a parallel build to
2989        work.
2991    16. If a pattern that contained .* following optional items at the start was
2992        studied, the wrong optimizing data was generated, leading to matching
2993        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2994        matching string must start with a or b or c. The correct conclusion for
2995        this pattern is that a match can start with any character.
2998    Version 4.4 13-Aug-03
2999    ---------------------
3001     1. In UTF-8 mode, a character class containing characters with values between
3002        127 and 255 was not handled correctly if the compiled pattern was studied.
3003        In fixing this, I have also improved the studying algorithm for such
3004        classes (slightly).
3006     2. Three internal functions had redundant arguments passed to them. Removal
3007        might give a very teeny performance improvement.
3009     3. Documentation bug: the value of the capture_top field in a callout is *one
3010        more than* the number of the hightest numbered captured substring.
3012     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3013        in incorrectly linking with a previously installed version. They now link
3014        explicitly with libpcre.la.
3016     5. configure.in no longer needs to recognize Cygwin specially.
3018     6. A problem in pcre.in for Windows platforms is fixed.
3020     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3021        pcretest, it used to include the size of the study block as part of its
3022        output. Unfortunately, the structure contains a field that has a different
3023        size on different hardware architectures. This meant that the tests that
3024        showed this size failed. As the block is currently always of a fixed size,
3025        this information isn't actually particularly useful in pcretest output, so
3026        I have just removed it.
3028     8. Three pre-processor statements accidentally did not start in column 1.
3029        Sadly, there are *still* compilers around that complain, even though
3030        standard C has not required this for well over a decade. Sigh.
3032     9. In pcretest, the code for checking callouts passed small integers in the
3033        callout_data field, which is a void * field. However, some picky compilers
3034        complained about the casts involved for this on 64-bit systems. Now
3035        pcretest passes the address of the small integer instead, which should get
3036        rid of the warnings.
3038    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3039        both compile and run time, and gives an error if an invalid UTF-8 sequence
3040        is found. There is a option for disabling this check in cases where the
3041        string is known to be correct and/or the maximum performance is wanted.
3043    11. In response to a bug report, I changed one line in Makefile.in from
3045            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3046        to
3047            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3049        to look similar to other lines, but I have no way of telling whether this
3050        is the right thing to do, as I do not use Windows. No doubt I'll get told
3051        if it's wrong...
3054    Version 4.3 21-May-03
3055    ---------------------
3057    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3058       Makefile.
3060    2. Some refactoring to improve the quality of the code:
3062       (i)   The utf8_table... variables are now declared "const".
3064       (ii)  The code for \cx, which used the "case flipping" table to upper case
3065             lower case letters, now just substracts 32. This is ASCII-specific,
3066             but the whole concept of \cx is ASCII-specific, so it seems
3067             reasonable.
3069       (iii) PCRE was using its character types table to recognize decimal and
3070             hexadecimal digits in the pattern. This is silly, because it handles
3071             only 0-9, a-f, and A-F, but the character types table is locale-
3072             specific, which means strange things might happen. A private
3073             table is now used for this - though it costs 256 bytes, a table is
3074             much faster than multiple explicit tests. Of course, the standard
3075             character types table is still used for matching digits in subject
3076             strings against \d.
3078       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3079             ending in _t are). So I've renamed it as ESC_tee.
3081    3. The first argument for regexec() in the POSIX wrapper should have been
3082       defined as "const".
3084    4. Changed pcretest to use malloc() for its buffers so that they can be
3085       Electric Fenced for debugging.
3087    5. There were several places in the code where, in UTF-8 mode, PCRE would try
3088       to read one or more bytes before the start of the subject string. Often this
3089       had no effect on PCRE's behaviour, but in some circumstances it could
3090       provoke a segmentation fault.
3092    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3093       to try to read one or more bytes before the start of the subject string.
3095    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3096       UTF-8 support could misbehave in various ways if the subject string
3097       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3098       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3099       back over UTF-8 characters.)
3102    Version 4.2 14-Apr-03
3103    ---------------------
3105    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3107    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3108         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3109         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3110         [WIN_PREFIX]: new variable, "cyg" for Cygwin
3111         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3112           and BUILD_EXEEXT
3113         Note: automatic setting of the BUILD variables is not yet working
3114         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3115           compile-time but not at link-time
3116         [LINK]: use for linking executables only
3117         make different versions for Windows and non-Windows
3118         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3119           libraries
3120         [LINK_FOR_BUILD]: new variable
3121         [OBJEXT]: use throughout
3122         [EXEEXT]: use throughout
3123         <winshared>: new target
3124         <wininstall>: new target
3125         <dftables.o>: use native compiler
3126         <dftables>: use native linker
3127         <install>: handle Windows platform correctly
3128         <clean>: ditto
3129         <check>: ditto
3130         copy DLL to top builddir before testing
3132       As part of these changes, -no-undefined was removed again. This was reported
3133       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3134       in any case.
3136    3. Some tidies to get rid of compiler warnings:
3138       . In the match_data structure, match_limit was an unsigned long int, whereas
3139         match_call_count was an int. I've made them both unsigned long ints.
3141       . In pcretest the fact that a const uschar * doesn't automatically cast to
3142         a void * provoked a warning.
3144       . Turning on some more compiler warnings threw up some "shadow" variables
3145         and a few more missing casts.
3147    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3148       option, a class that contained a single character with a value between 128
3149       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3151    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3152       option, a class that contained several characters, but with at least one
3153       whose value was between 128 and 255 caused PCRE to crash.
3156    Version 4.1 12-Mar-03
3157    ---------------------
3159    1. Compiling with gcc -pedantic found a couple of places where casts were
3160    needed, and a string in dftables.c that was longer than standard compilers are
3161    required to support.
3163    2. Compiling with Sun's compiler found a few more places where the code could
3164    be tidied up in order to avoid warnings.
3166    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3167    first of these names is deprecated in the latest Autoconf in favour of the name
3168    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3169    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3170    analogy I have changed it to CFLAGS_FOR_BUILD.
3172    4. Added -no-undefined to the linking command in the Makefile, because this is
3173    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3174    linking step for the pcreposix library.
3176    5. PCRE was failing to diagnose the case of two named groups with the same
3177    name.
3179    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3180    literal character that is needed in the subject for a match, and scans along to
3181    ensure that it is present before embarking on the full matching process. This
3182    saves time in cases of nested unlimited repeats that are never going to match.
3183    Problem: the scan can take a lot of time if the subject is very long (e.g.
3184    megabytes), thus penalizing straightforward matches. It is now done only if the
3185    amount of subject to be scanned is less than 1000 bytes.
3187    7. A lesser problem with the same optimization is that it was recording the
3188    first character of an anchored pattern as "needed", thus provoking a search
3189    right along the subject, even when the first match of the pattern was going to
3190    fail. The "needed" character is now not set for anchored patterns, unless it
3191    follows something in the pattern that is of non-fixed length. Thus, it still
3192    fulfils its original purpose of finding quick non-matches in cases of nested
3193    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3196    Version 4.0 17-Feb-03
3197    ---------------------
3199    1. If a comment in an extended regex that started immediately after a meta-item
3200    extended to the end of string, PCRE compiled incorrect data. This could lead to
3201    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3203    2. Moved to autoconf 2.53 and libtool 1.4.2.
3205    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3206    the special perltest8 script is no longer needed - all the tests can be run
3207    from a single perltest script.
3209    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3210    by \s. It has now been removed in PCRE. This means it isn't recognized as
3211    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3212    class [:space:] *does* include VT, thereby creating a mess.
3214    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3215    space and tab.
3217    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3218    its new features into the main test script, reducing the number of scripts.
3220    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3221    were backward compatible, and made the (?i) apply to the whole pattern, as if
3222    /i were given. Now it behaves more logically, and applies the option setting
3223    only to what follows. PCRE has been changed to follow suit. However, if it
3224    finds options settings right at the start of the pattern, it extracts them into
3225    the global options, as before. Thus, they show up in the info data.
3227    8. Added support for the \Q...\E escape sequence. Characters in between are
3228    treated as literals. This is slightly different from Perl in that $ and @ are
3229    also handled as literals inside the quotes. In Perl, they will cause variable
3230    interpolation. Note the following examples:
3232        Pattern            PCRE matches      Perl matches
3234        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
3235        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
3236        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
3238    For compatibility with Perl, \Q...\E sequences are recognized inside character
3239    classes as well as outside them.
3241    9. Re-organized 3 code statements in pcretest to avoid "overflow in
3242    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3243    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3244    signed/unsigned warnings.
3246    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3247    option for pcretest, so I've replaced it by a simple function that does just
3248    that job.
3250    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3251    "pcregrep -".
3253    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3254    Java package. This provides some syntactic sugar for simple cases of what my
3255    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3256    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3257    item, you can use this simplified notation. Note that only makes sense with
3258    greedy quantifiers. Consequently, the use of the possessive quantifier forces
3259    greediness, whatever the setting of the PCRE_UNGREEDY option.
3261    13. A change of greediness default within a pattern was not taking effect at
3262    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3263    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3264    was abstracted outside.
3266    14. PCRE now supports the \G assertion. It is true when the current matching
3267    position is at the start point of the match. This differs from \A when the
3268    starting offset is non-zero. Used with the /g option of pcretest (or similar
3269    code), it works in the same way as it does for Perl's /g option. If all
3270    alternatives of a regex begin with \G, the expression is anchored to the start
3271    match position, and the "anchored" flag is set in the compiled expression.
3273    15. Some bugs concerning the handling of certain option changes within patterns
3274    have been fixed. These applied to options other than (?ims). For example,
3275    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3276    been the other way round. Some of this was related to change 7 above.
3278    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3279    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3280    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3281    POSIX classes only within a class (e.g. /[[:alpha:]]/).
3283    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3284    mode. Unlike ".", it always matches newline, whatever the setting of
3285    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3286    assertions. Perl allows it, but it doesn't (in general) work because it can't
3287    calculate the length of the lookbehind. At least, that's the case for Perl
3288    5.8.0 - I've been told they are going to document that it doesn't work in
3289    future.
3291    18. Added an error diagnosis for escapes that PCRE does not support: these are
3292    \L, \l, \N, \P, \p, \U, \u, and \X.
3294    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3295    reading past the end of the pattern in cases such as /[abcd/.
3297    20. PCRE was getting more memory than necessary for patterns with classes that
3298    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3300    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3301    compiling PCRE for use with Virtual Pascal.
3303    22. Small fix to the Makefile to make it work properly if the build is done
3304    outside the source tree.
3306    23. Added a new extension: a condition to go with recursion. If a conditional
3307    subpattern starts with (?(R) the "true" branch is used if recursion has
3308    happened, whereas the "false" branch is used only at the top level.
3310    24. When there was a very long string of literal characters (over 255 bytes
3311    without UTF support, over 250 bytes with UTF support), the computation of how
3312    much memory was required could be incorrect, leading to segfaults or other
3313    strange effects.
3315    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3316    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3317    there was a subsequent back reference to those brackets. This meant that, for
3318    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3319    possible to check for precisely this case. All we can do is abandon the
3320    optimization if .* occurs inside capturing brackets when there are any back
3321    references whatsoever. (See below for a better fix that came later.)
3323    26. The handling of the optimization for finding the first character of a
3324    non-anchored pattern, and for finding a character that is required later in the
3325    match were failing in some cases. This didn't break the matching; it just
3326    failed to optimize when it could. The way this is done has been re-implemented.
3328    27. Fixed typo in error message for invalid (?R item (it said "(?p").
3330    28. Added a new feature that provides some of the functionality that Perl
3331    provides with (?{...}). The facility is termed a "callout". The way it is done
3332    in PCRE is for the caller to provide an optional function, by setting
3333    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3334    global variable. By default it is unset, which disables all calling out. To get
3335    the function called, the regex must include (?C) at appropriate points. This
3336    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3337    This provides a means of identifying different callout points. When PCRE
3338    reaches such a point in the regex, if pcre_callout has been set, the external
3339    function is called. It is provided with data in a structure called
3340    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3341    matching continues; if it returns a non-zero value, the match at the current
3342    point fails. However, backtracking will occur if possible. [This was changed
3343    later and other features added - see item 49 below.]
3345    29. pcretest is upgraded to test the callout functionality. It provides a
3346    callout function that displays information. By default, it shows the start of
3347    the match and the current position in the text. There are some new data escapes
3348    to vary what happens:
3350        \C+         in addition, show current contents of captured substrings
3351        \C-         do not supply a callout function
3352        \C!n        return 1 when callout number n is reached
3353        \C!n!m      return 1 when callout number n is reached for the mth time
3355    30. If pcregrep was called with the -l option and just a single file name, it
3356    output "<stdin>" if a match was found, instead of the file name.
3358    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3359    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3360    pcre_exec(). This saves a malloc/free per call. The default value of
3361    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3362    when configuring.
3364    32. The default maximum size of a compiled pattern is 64K. There have been a
3365    few cases of people hitting this limit. The code now uses macros to handle the
3366    storing of links as offsets within the compiled pattern. It defaults to 2-byte
3367    links, but this can be changed to 3 or 4 bytes by --with-link-size when
3368    configuring. Tests 2 and 5 work only with 2-byte links because they output
3369    debugging information about compiled patterns.
3371    33. Internal code re-arrangements:
3373    (a) Moved the debugging function for printing out a compiled regex into
3374        its own source file (printint.c) and used #include to pull it into
3375        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3376        separate copies.
3378    (b) Defined the list of op-code names for debugging as a macro in
3379        internal.h so that it is next to the definition of the opcodes.
3381    (c) Defined a table of op-code lengths for simpler skipping along compiled
3382        code. This is again a macro in internal.h so that it is next to the
3383        definition of the opcodes.
3385    34. Added support for recursive calls to individual subpatterns, along the
3386    lines of Robin Houston's patch (but implemented somewhat differently).
3388    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3389    allow it to read and process whole directories in Win32. This code was
3390    contributed by Lionel Fourquaux; it has not been tested by me.
3392    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3393    used to name a group. Names consist of alphanumerics and underscores, and must
3394    be unique. Back references use the syntax (?P=name) and recursive calls use
3395    (?P>name) which is a PCRE extension to the Python extension. Groups still have
3396    numbers. The function pcre_fullinfo() can be used after compilation to extract
3397    a name/number map. There are three relevant calls:
3399      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
3400      PCRE_INFO_NAMECOUNT            yields the number of entries
3401      PCRE_INFO_NAMETABLE            yields a pointer to the map.
3403    The map is a vector of fixed-size entries. The size of each entry depends on
3404    the length of the longest name used. The first two bytes of each entry are the
3405    group number, most significant byte first. There follows the corresponding
3406    name, zero terminated. The names are in alphabetical order.
3408    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3409    case instead of 255. Making it the same both with and without UTF-8 support
3410    means that the same test output works with both.
3412    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3413    calling malloc() with a zero argument.
3415    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3416    optimization. I've improved things by keeping a bitmap of backreferences with
3417    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3418    fact referenced, the optimization can be applied. It is unlikely that a
3419    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3420    the match to follow \n) will appear inside brackets with a number greater than
3421    31, but if it does, any back reference > 31 suppresses the optimization.
3423    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3424    of disabling numbered capturing parentheses. Any opening parenthesis that is
3425    not followed by ? behaves as if it were followed by ?: but named parentheses
3426    can still be used for capturing (and they will acquire numbers in the usual
3427    way).
3429    41. Redesigned the return codes from the match() function into yes/no/error so
3430    that errors can be passed back from deep inside the nested calls. A malloc
3431    failure while inside a recursive subpattern call now causes the
3432    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3434    42. It is now possible to set a limit on the number of times the match()
3435    function is called in a call to pcre_exec(). This facility makes it possible to
3436    limit the amount of recursion and backtracking, though not in a directly
3437    obvious way, because the match() function is used in a number of different
3438    circumstances. The count starts from zero for each position in the subject
3439    string (for non-anchored patterns). The default limit is, for compatibility, a
3440    large number, namely 10 000 000. You can change this in two ways:
3442    (a) When configuring PCRE before making, you can use --with-match-limit=n
3443        to set a default value for the compiled library.
3445    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3446        a different value is set. See 45 below.
3448    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3450    43. Added a new function pcre_config(int, void *) to enable run-time extraction
3451    of things that can be changed at compile time. The first argument specifies
3452    what is wanted and the second points to where the information is to be placed.
3453    The current list of available information is:
3455      PCRE_CONFIG_UTF8
3457    The output is an integer that is set to one if UTF-8 support is available;
3458    otherwise it is set to zero.
3462    The output is an integer that it set to the value of the code that is used for
3463    newline. It is either LF (10) or CR (13).
3467    The output is an integer that contains the number of bytes used for internal
3468    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3472    The output is an integer that contains the threshold above which the POSIX
3473    interface uses malloc() for output vectors. See item 31 above.
3477    The output is an unsigned integer that contains the default limit of the number
3478    of match() calls in a pcre_exec() execution. See 42 above.
3480    44. pcretest has been upgraded by the addition of the -C option. This causes it
3481    to extract all the available output from the new pcre_config() function, and to
3482    output it. The program then exits immediately.
3484    45. A need has arisen to pass over additional data with calls to pcre_exec() in
3485    order to support additional features. One way would have been to define
3486    pcre_exec2() (for example) with extra arguments, but this would not have been
3487    extensible, and would also have required all calls to the original function to
3488    be mapped to the new one. Instead, I have chosen to extend the mechanism that
3489    is used for passing in "extra" data from pcre_study().
3491    The pcre_extra structure is now exposed and defined in pcre.h. It currently
3492    contains the following fields:
3494      flags         a bitmap indicating which of the following fields are set
3495      study_data    opaque data from pcre_study()
3496      match_limit   a way of specifying a limit on match() calls for a specific
3497                      call to pcre_exec()
3498      callout_data  data for callouts (see 49 below)
3500    The flag bits are also defined in pcre.h, and are
3506    The pcre_study() function now returns one of these new pcre_extra blocks, with
3507    the actual study data pointed to by the study_data field, and the
3508    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3509    before. That is, this change is entirely upwards-compatible and requires no
3510    change to existing code.
3512    If you want to pass in additional data to pcre_exec(), you can either place it
3513    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3514    block.
3516    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3517    data string contains the escape sequence \M, pcretest calls pcre_exec() several
3518    times with different match limits, until it finds the minimum value needed for
3519    pcre_exec() to complete. The value is then output. This can be instructive; for
3520    most simple matches the number is quite small, but for pathological cases it
3521    gets very large very quickly.
3523    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3524    returns the size of the data block pointed to by the study_data field in a
3525    pcre_extra block, that is, the value that was passed as the argument to
3526    pcre_malloc() when PCRE was getting memory in which to place the information
3527    created by pcre_study(). The fourth argument should point to a size_t variable.
3528    pcretest has been extended so that this information is shown after a successful
3529    pcre_study() call when information about the compiled regex is being displayed.
3531    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3532    because what follows is always an absolute path. (Later: it turns out that this
3533    is more than cosmetic for MinGW, because it doesn't like empty path
3534    components.)
3536    49. Some changes have been made to the callout feature (see 28 above):
3538    (i)  A callout function now has three choices for what it returns:
3540           0  =>  success, carry on matching
3541         > 0  =>  failure at this point, but backtrack if possible
3542         < 0  =>  serious error, return this value from pcre_exec()
3544         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3545         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3546         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3547         use by callout functions. It will never be used by PCRE itself.
3549    (ii) The pcre_extra structure (see 45 above) has a void * field called
3550         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3551         pcre_callout_block structure has a field of the same name. The contents of
3552         the field passed in the pcre_extra structure are passed to the callout
3553         function in the corresponding field in the callout block. This makes it
3554         easier to use the same callout-containing regex from multiple threads. For
3555         testing, the pcretest program has a new data escape
3557           \C*n        pass the number n (may be negative) as callout_data
3559         If the callout function in pcretest receives a non-zero value as
3560         callout_data, it returns that value.
3562    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3563    there were some redundant $(CFLAGS) in commands that are now specified as
3564    $(LINK), which already includes $(CFLAGS).
3566    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3567    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3568    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3569    one-byte characters throughout. Note that case-insensitive matching applies
3570    only to characters whose values are less than 256. PCRE doesn't support the
3571    notion of cases for higher-valued characters.
3573    (i)   A character class whose characters are all within 0-255 is handled as
3574          a bit map, and the map is inverted for negative classes. Previously, a
3575          character > 255 always failed to match such a class; however it should
3576          match if the class was a negative one (e.g. [^ab]). This has been fixed.
3578    (ii)  A negated character class with a single character < 255 is coded as
3579          "not this character" (OP_NOT). This wasn't working properly when the test
3580          character was multibyte, either singly or repeated.
3582    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3583          mode, for example: \x{100}{2,3}.
3585    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3586          singly or repeated) now correctly test multibyte characters. However,
3587          PCRE doesn't recognize any characters with values greater than 255 as
3588          digits, spaces, or word characters. Such characters always match \D, \S,
3589          and \W, and never match \d, \s, or \w.
3591    (v)   Classes may now contain characters and character ranges with values
3592          greater than 255. For example: [ab\x{100}-\x{400}].
3594    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
3595          PCRE in UTF-8 mode.
3597    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3598    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3599    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3600    value.)
3602    53. The single man page has become too large. I have therefore split it up into
3603    a number of separate man pages. These also give rise to individual HTML pages;
3604    these are now put in a separate directory, and there is an index.html page that
3605    lists them all. Some hyperlinking between the pages has been installed.
3607    54. Added convenience functions for handling named capturing parentheses.
3609    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3610    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3611    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3612    are faulted.
3614    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3615    calling configure. These values are used when compiling the dftables.c program
3616    which is run to generate the source of the default character tables. They
3617    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3618    you will need to set these values.
3620    57. Updated the building process for Windows DLL, as provided by Fred Cox.
3623    Version 3.9 02-Jan-02
3624    ---------------------
3626    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3628    2. If --disable-static was given, the building process failed when trying to
3629    build pcretest and pcregrep. (For some reason it was using libtool to compile
3630    them, which is not right, as they aren't part of the library.)
3633    Version 3.8 18-Dec-01
3634    ---------------------
3636    1. The experimental UTF-8 code was completely screwed up. It was packing the
3637    bytes in the wrong order. How dumb can you get?
3640    Version 3.7 29-Oct-01
3641    ---------------------
3643    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3644    This caused pcretest, when used on the test data, to segfault. Unfortunately,
3645    this didn't happen under Solaris 8, where I normally test things.
3647    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3648    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3649    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3650    this fix an hour or so after the initial 3.7 release.)
3653    Version 3.6 23-Oct-01
3654    ---------------------
3656    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3657    offsets passed as NULL with zero offset count.
3659    2. The config.guess and config.sub files had not been updated when I moved to
3660    the latest autoconf.
3663    Version 3.5 15-Aug-01
3664    ---------------------
3666    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3667    had been forgotten.
3669    2. By using declared but undefined structures, we can avoid using "void"
3670    definitions in pcre.h while keeping the internal definitions of the structures
3671    private.
3673    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3674    user point of view, this means that both static and shared libraries are built
3675    by default, but this can be individually controlled. More of the work of
3676    handling this static/shared cases is now inside libtool instead of PCRE's make
3677    file.
3679    4. The pcretest utility is now installed along with pcregrep because it is
3680    useful for users (to test regexs) and by doing this, it automatically gets
3681    relinked by libtool. The documentation has been turned into a man page, so
3682    there are now .1, .txt, and .html versions in /doc.
3684    5. Upgrades to pcregrep:
3685       (i)   Added long-form option names like gnu grep.
3686       (ii)  Added --help to list all options with an explanatory phrase.
3687       (iii) Added -r, --recursive to recurse into sub-directories.
3688       (iv)  Added -f, --file to read patterns from a file.
3690    6. pcre_exec() was referring to its "code" argument before testing that
3691    argument for NULL (and giving an error if it was NULL).
3693    7. Upgraded Makefile.in to allow for compiling in a different directory from
3694    the source directory.
3696    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3697    options bits, the pointer it was passed was to an int instead of to an unsigned
3698    long int. This mattered only on 64-bit systems.
3700    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3701    generated) instead of pcre.in, which it its source. Also made the same change
3702    in several of the .c files.
3704    10. A new release of gcc defines printf() as a macro, which broke pcretest
3705    because it had an ifdef in the middle of a string argument for printf(). Fixed
3706    by using separate calls to printf().
3708    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3709    script, to force use of CR or LF instead of \n in the source. On non-Unix
3710    systems, the value can be set in config.h.
3712    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3713    absolute limit. Changed the text of the error message to make this clear, and
3714    likewise updated the man page.
3716    13. The limit of 99 on the number of capturing subpatterns has been removed.
3717    The new limit is 65535, which I hope will not be a "real" limit.
3720    Version 3.4 22-Aug-00
3721    ---------------------
3723    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3725    2. Diagnose condition (?(0) as an error instead of crashing on matching.
3728    Version 3.3 01-Aug-00
3729    ---------------------
3731    1. If an octal character was given, but the value was greater than \377, it
3732    was not getting masked to the least significant bits, as documented. This could
3733    lead to crashes in some systems.
3735    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3736    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3738    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3739    These just pass their arguments on to (pcre_free)(), but they are provided
3740    because some uses of PCRE bind it to non-C systems that can call its functions,
3741    but cannot call free() or pcre_free() directly.
3743    4. Add "make test" as a synonym for "make check". Corrected some comments in
3744    the Makefile.
3746    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3747    Makefile.
3749    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3750    command called pgrep for grepping around the active processes.
3752    7. Added the beginnings of support for UTF-8 character strings.
3754    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3755    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3756    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3757    out for the ar command.)
3760    Version 3.2 12-May-00
3761    ---------------------
3763    This is purely a bug fixing release.
3765    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3766    of ZA. This was just one example of several cases that could provoke this bug,
3767    which was introduced by change 9 of version 2.00. The code for breaking
3768    infinite loops after an iteration that matches an empty string was't working
3769    correctly.
3771    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3772    when matched against abbab (for example). After matching an empty string, it
3773    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3774    caused it to match further down the string than it should.
3776    3. The code contained an inclusion of sys/types.h. It isn't clear why this
3777    was there because it doesn't seem to be needed, and it causes trouble on some
3778    systems, as it is not a Standard C header. It has been removed.
3780    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3781    were reported on the Macintosh. The changes were from
3783      while ((c = *(++ptr)) != 0 && c != '\n');
3784    to
3785      while ((c = *(++ptr)) != 0 && c != '\n') ;
3787    Totally extraordinary, but if that's what it takes...
3789    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3790    available. Added HAVE_BCOPY and an autoconf test for it; if neither
3791    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3792    assumes the way PCRE uses memmove() (always moving upwards).
3794    6. PCRE is being used in one environment where strchr() is not available. There
3795    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3796    faster code anyway.
3799    Version 3.1 09-Feb-00
3800    ---------------------
3802    The only change in this release is the fixing of some bugs in Makefile.in for
3803    the "install" target:
3805    (1) It was failing to install pcreposix.h.
3807    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3810    Version 3.0 01-Feb-00
3811    ---------------------
3813    1. Add support for the /+ modifier to perltest (to output $` like it does in
3814    pcretest).
3816    2. Add support for the /g modifier to perltest.
3818    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3819    matches null strings.
3821    4. Fix perltest so that it doesn't do unwanted things when fed an empty
3822    pattern. Perl treats empty patterns specially - it reuses the most recent
3823    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3824  <