ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 73 by nigel, Sat Feb 24 21:40:30 2007 UTC revision 701 by ph10, Tue Sep 20 11:30:56 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.20 12-Sep-2011
5    ------------------------
7    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
8        a POSIX class. After further experiments with Perl, which convinced me that
9        Perl has bugs and confusions, a closing square bracket is no longer allowed
10        in a POSIX name. This bug also affected patterns with classes that started
11        with full stops.
13    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
14        captured substring, but while checking the failing first alternative,
15        substring 1 is temporarily captured. If the output vector supplied to
16        pcre_exec() was not big enough for this capture, the yield of the function
17        was still zero ("insufficient space for captured substrings"). This cannot
18        be totally fixed without adding another stack variable, which seems a lot
19        of expense for a edge case. However, I have improved the situation in cases
20        such as /(a)(b)x|abc/ matched against "abc", where the return code
21        indicates that fewer than the maximum number of slots in the ovector have
22        been set.
24    3.  Related to (2) above: when there are more back references in a pattern than
25        slots in the output vector, pcre_exec() uses temporary memory during
26        matching, and copies in the captures as far as possible afterwards. It was
27        using the entire output vector, but this conflicts with the specification
28        that only 2/3 is used for passing back captured substrings. Now it uses
29        only the first 2/3, for compatibility. This is, of course, another edge
30        case.
32    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
33        main code base, and can be used by building with --enable-jit. When this is
34        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
35        runtime --no-jit option is given.
37    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
38        ovector, the return from the function was zero, implying that there were
39        other matches that did not fit. The correct "exactly full" value is now
40        returned.
42    6.  If a subpattern that was called recursively or as a subroutine contained
43        (*PRUNE) or any other control that caused it to give a non-standard return,
44        invalid errors such as "Error -26 (nested recursion at the same subject
45        position)" or even infinite loops could occur.
47    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
48        computing the minimum length on reaching *ACCEPT, and so ended up with the
49        wrong value of 1 rather than 0. Further investigation indicates that
50        computing a minimum subject length in the presence of *ACCEPT is difficult
51        (think back references, subroutine calls), and so I have changed the code
52        so that no minimum is registered for a pattern that contains *ACCEPT.
54    8.  If (*THEN) was present in the first (true) branch of a conditional group,
55        it was not handled as intended.
57    9.  Replaced RunTest.bat with the much improved version provided by Sheri
58        Pierce.
60    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
61        the first byte in a match must be "a".
64    Version 8.13 16-Aug-2011
65    ------------------------
67    1.  The Unicode data tables have been updated to Unicode 6.0.0.
69    2.  Two minor typos in pcre_internal.h have been fixed.
71    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
72        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
73        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
75    4.  There were a number of related bugs in the code for matching backrefences
76        caselessly in UTF-8 mode when codes for the characters concerned were
77        different numbers of bytes. For example, U+023A and U+2C65 are an upper
78        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
79        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
80        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
81        2-byte code at the end of the subject (it thought there wasn't enough data
82        left).
84    5.  Comprehensive information about what went wrong is now returned by
85        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
86        as the output vector has at least 2 elements. The offset of the start of
87        the failing character and a reason code are placed in the vector.
89    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
90        now returned is for the first byte of the failing character, instead of the
91        last byte inspected. This is an incompatible change, but I hope it is small
92        enough not to be a problem. It makes the returned offset consistent with
93        pcre_exec() and pcre_dfa_exec().
95    7.  pcretest now gives a text phrase as well as the error number when
96        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
97        failure, the offset and reason code are output.
99    8.  When \R was used with a maximizing quantifier it failed to skip backwards
100        over a \r\n pair if the subsequent match failed. Instead, it just skipped
101        back over a single character (\n). This seems wrong (because it treated the
102        two characters as a single entity when going forwards), conflicts with the
103        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
104        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
105        has been changed.
107    9.  Some internal refactoring has changed the processing so that the handling
108        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
109        time (the PCRE_DOTALL option was changed this way some time ago: version
110        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
111        which was always a bit of a fudge. It also means that there is one less
112        argument for the match() function, which reduces its stack requirements
113        slightly. This change also fixes an incompatibility with Perl: the pattern
114        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
116    10. More internal refactoring has drastically reduced the number of recursive
117        calls to match() for possessively repeated groups such as (abc)++ when
118        using pcre_exec().
120    11. While implementing 10, a number of bugs in the handling of groups were
121        discovered and fixed:
123        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
124        (a|)*(?1) gave a compile-time internal error.
125        ((a|)+)+  did not notice that the outer group could match an empty string.
126        (^a|^)+   was not marked as anchored.
127        (.*a|.*)+ was not marked as matching at start or after a newline.
129    12. Yet more internal refactoring has removed another argument from the match()
130        function. Special calls to this function are now indicated by setting a
131        value in a variable in the "match data" data block.
133    13. Be more explicit in pcre_study() instead of relying on "default" for
134        opcodes that mean there is no starting character; this means that when new
135        ones are added and accidentally left out of pcre_study(), testing should
136        pick them up.
138    14. The -s option of pcretest has been documented for ages as being an old
139        synonym of -m (show memory usage). I have changed it to mean "force study
140        for every regex", that is, assume /S for every regex. This is similar to -i
141        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
142        using it. It makes it easier to run collections of tests with and without
143        study enabled, and thereby test pcre_study() more easily. All the standard
144        tests are now run with and without -s (but some patterns can be marked as
145        "never study" - see 20 below).
147    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
148        restoration of the capturing data to the outer values was not happening
149        correctly.
151    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
152        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
153        pattern had matched an empty string, and so incorrectly returned a no
154        match.
156    17. There was optimizing code for the last branch of non-capturing parentheses,
157        and also for the obeyed branch of a conditional subexpression, which used
158        tail recursion to cut down on stack usage. Unfortunately, now that there is
159        the possibility of (*THEN) occurring in these branches, tail recursion is
160        no longer possible because the return has to be checked for (*THEN). These
161        two optimizations have therefore been removed.
163    18. If a pattern containing \R was studied, it was assumed that \R always
164        matched two bytes, thus causing the minimum subject length to be
165        incorrectly computed because \R can also match just one byte.
167    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
168        was incorrectly computed.
170    20. If /S is present twice on a test pattern in pcretest input, it now
171        *disables* studying, thereby overriding the use of -s on the command line
172        (see 14 above). This is necessary for one or two tests to keep the output
173        identical in both cases.
175    21. When (*ACCEPT) was used in an assertion that matched an empty string and
176        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
178    22. When an atomic group that contained a capturing parenthesis was
179        successfully matched, but the branch in which it appeared failed, the
180        capturing was not being forgotten if a higher numbered group was later
181        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
182        group 1 to "a", when in fact it should be unset. This applied to multi-
183        branched capturing and non-capturing groups, repeated or not, and also to
184        positive assertions (capturing in negative assertions does not happen
185        in PCRE) and also to nested atomic groups.
187    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
188        subject after a captured substring, to make it easier to tell which of a
189        number of identical substrings has been captured.
191    24. The way atomic groups are processed by pcre_exec() has been changed so that
192        if they are repeated, backtracking one repetition now resets captured
193        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
194        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
195        "aaa". Previously, it would have been "a". As part of this code
196        refactoring, the way recursive calls are handled has also been changed.
198    25. If an assertion condition captured any substrings, they were not passed
199        back unless some other capturing happened later. For example, if
200        (?(?=(a))a) was matched against "a", no capturing was returned.
202    26. When studying a pattern that contained subroutine calls or assertions,
203        the code for finding the minimum length of a possible match was handling
204        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
205        group 1 called group 2 while simultaneously a separate group 2 called group
206        1). A stack overflow occurred in this case. I have fixed this by limiting
207        the recursion depth to 10.
209    27. Updated RunTest.bat in the distribution to the version supplied by Tom
210        Fortmann. This supports explicit test numbers on the command line, and has
211        argument validation and error reporting.
213    28. An instance of \X with an unlimited repeat could fail if at any point the
214        first character it looked at was a mark character.
216    29. Some minor code refactoring concerning Unicode properties and scripts
217        should reduce the stack requirement of match() slightly.
219    30. Added the '=' option to pcretest to check the setting of unused capturing
220        slots at the end of the pattern, which are documented as being -1, but are
221        not included in the return count.
223    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
224        compiled something random. Now it gives a compile-time error (as does
225        Perl).
227    32. A *MARK encountered during the processing of a positive assertion is now
228        recorded and passed back (compatible with Perl).
230    33. If --only-matching or --colour was set on a pcregrep call whose pattern
231        had alternative anchored branches, the search for a second match in a line
232        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
233        matched the line "0102" twice. The same bug affected patterns that started
234        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
235        twice.
237    34. Previously, PCRE did not allow quantification of assertions. However, Perl
238        does, and because of capturing effects, quantifying parenthesized
239        assertions may at times be useful. Quantifiers are now allowed for
240        parenthesized assertions.
242    35. A minor code tidy in pcre_compile() when checking options for \R usage.
244    36. \g was being checked for fancy things in a character class, when it should
245        just be a literal "g".
247    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
248        appearance of a nested POSIX class supersedes an apparent external class.
249        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
250        unescaped square brackets may also appear as part of class names. For
251        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
252        more like Perl. (But see 8.20/1 above.)
254    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
255        was because it thought it was \N{name}, which is not supported).
257    39. Add minix to OS list not supporting the -S option in pcretest.
259    40. PCRE tries to detect cases of infinite recursion at compile time, but it
260        cannot analyze patterns in sufficient detail to catch mutual recursions
261        such as ((?1))((?2)). There is now a runtime test that gives an error if a
262        subgroup is called recursively as a subpattern for a second time at the
263        same position in the subject string. In previous releases this might have
264        been caught by the recursion limit, or it might have run out of stack.
266    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
267        happen only once. PCRE was, however incorrectly giving a compile time error
268        "recursive call could loop indefinitely" because it cannot analyze the
269        pattern in sufficient detail. The compile time test no longer happens when
270        PCRE is compiling a conditional subpattern, but actual runaway loops are
271        now caught at runtime (see 40 above).
273    42. It seems that Perl allows any characters other than a closing parenthesis
274        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
275        has been changed to be the same.
277    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
278        as not to get warnings when autogen.sh is called. Also changed
279        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
281    44. To help people who use pcregrep to scan files containing exceedingly long
282        lines, the following changes have been made:
284        (a) The default value of the buffer size parameter has been increased from
285            8K to 20K. (The actual buffer used is three times this size.)
287        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
288            PCRE is built.
290        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
291            to be set at run time.
293        (d) Numerical values in pcregrep options can be followed by K or M, for
294            example --buffer-size=50K.
296        (e) If a line being scanned overflows pcregrep's buffer, an error is now
297            given and the return code is set to 2.
299    45. Add a pointer to the latest mark to the callout data block.
301    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
302        partial match of an empty string instead of no match. This was specific to
303        the use of ".".
305    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
306        complete match instead of a partial match. This bug was dependent on both
307        the PCRE_UTF8 and PCRE_DOTALL options being set.
309    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
310        starting byte set, because \b was not being ignored.
313    Version 8.12 15-Jan-2011
314    ------------------------
316    1.  Fixed some typos in the markup of the man pages, and wrote a script that
317        checks for such things as part of the documentation building process.
319    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
320        --match-limit and --recursion-limit options (added for 8.11). In
321        particular, this made one of the standard tests fail. (The integer value
322        went into the wrong half of a long int.)
324    3.  If the --colour option was given to pcregrep with -v (invert match), it
325        did strange things, either producing crazy output, or crashing. It should,
326        of course, ignore a request for colour when reporting lines that do not
327        match.
329    4.  Another pcregrep bug caused similar problems if --colour was specified with
330        -M (multiline) and the pattern match finished with a line ending.
332    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
333        matched in multiline mode, the following line was shown as part of the
334        match. This seems wrong, so I have changed it.
336    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
337        the check for further matches in the same line (so they could be coloured)
338        to overrun the end of the current line. If another match was found, it was
339        incorrectly shown (and then shown again when found in the next line).
341    7.  If pcregrep was compiled under Windows, there was a reference to the
342        function pcregrep_exit() before it was defined. I am assuming this was
343        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
344        reported by a user. I've moved the definition above the reference.
347    Version 8.11 10-Dec-2010
348    ------------------------
350    1.  (*THEN) was not working properly if there were untried alternatives prior
351        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
352        backtracked to try for "b" instead of moving to the next alternative branch
353        at the same level (in this case, to look for "c"). The Perl documentation
354        is clear that when (*THEN) is backtracked onto, it goes to the "next
355        alternative in the innermost enclosing group".
357    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
358        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
359        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
360        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
361        (*THEN).
363    3.  If \s appeared in a character class, it removed the VT character from
364        the class, even if it had been included by some previous item, for example
365        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
366        of \s, but is part of the POSIX "space" class.)
368    4.  A partial match never returns an empty string (because you can always
369        match an empty string at the end of the subject); however the checking for
370        an empty string was starting at the "start of match" point. This has been
371        changed to the "earliest inspected character" point, because the returned
372        data for a partial match starts at this character. This means that, for
373        example, /(?<=abc)def/ gives a partial match for the subject "abc"
374        (previously it gave "no match").
376    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
377        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
378        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
379        has an implication that the given string is incomplete (because a partial
380        match is preferred over a full match). For this reason, these items now
381        give a partial match in this situation. [Aside: previously, the one case
382        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
383        match rather than a full match, which was wrong by the old rules, but is
384        now correct.]
386    6.  There was a bug in the handling of #-introduced comments, recognized when
387        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
388        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
389        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
390        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
391        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
392        places in pcre_compile().
394    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
395        comments when looking ahead for named forward references to subpatterns,
396        the only newline sequence it recognized was NL. It now handles newlines
397        according to the set newline convention.
399    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
400        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
401        cater for a lack of strerror(). These oversights have been fixed.
403    9.  Added --match-limit and --recursion-limit to pcregrep.
405    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
407    11. When the -o option was used, pcregrep was setting a return code of 1, even
408        when matches were found, and --line-buffered was not being honoured.
410    12. Added an optional parentheses number to the -o and --only-matching options
411        of pcregrep.
413    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
414        can match an empty string. The code to do it in pcretest and pcredemo
415        needed fixing:
417        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
418            only one byte after an empty string match just before CRLF (this case
419            just got forgotten; "any" and "anycrlf" were OK).
421        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
422            mode when an empty string match preceded an ASCII character followed by
423            a non-ASCII character. (The code for advancing by one character rather
424            than one byte was nonsense.)
426        (c) The pcredemo.c sample program did not have any code at all to handle
427            the cases when CRLF is a valid newline sequence.
429    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
430        as a starting offset was within the subject string. There is now a new
431        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
432        negative or greater than the length of the string. In order to test this,
433        pcretest is extended to allow the setting of negative starting offsets.
435    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
436        starting offset points to the beginning of a UTF-8 character was
437        unnecessarily clumsy. I tidied it up.
439    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
440        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
442    17. Nobody had reported that the --include_dir option, which was added in
443        release 7.7 should have been called --include-dir (hyphen, not underscore)
444        for compatibility with GNU grep. I have changed it to --include-dir, but
445        left --include_dir as an undocumented synonym, and the same for
446        --exclude-dir, though that is not available in GNU grep, at least as of
447        release 2.5.4.
449    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
450        characters from a string of bytes) have been redefined so as not to use
451        loops, in order to improve performance in some environments. At the same
452        time, I abstracted some of the common code into auxiliary macros to save
453        repetition (this should not affect the compiled code).
455    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
456        compile-time error is now given if \c is not followed by an ASCII
457        character, that is, a byte less than 128. (In EBCDIC mode, the code is
458        different, and any byte value is allowed.)
460    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
461        START_OPTIMIZE option, which is now allowed at compile time - but just
462        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
463        to pcregrep and other applications that have no direct access to PCRE
464        options. The new /Y option in pcretest sets this option when calling
465        pcre_compile().
467    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
468        back references. Groups containing recursive back references were forced to
469        be atomic by that change, but in the case of named groups, the amount of
470        memory required was incorrectly computed, leading to "Failed: internal
471        error: code overflow". This has been fixed.
473    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
474        pcretest.c, to avoid build problems in some Borland environments.
477    Version 8.10 25-Jun-2010
478    ------------------------
480    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
481        THEN.
483    2.  (*ACCEPT) was not working when inside an atomic group.
485    3.  Inside a character class, \B is treated as a literal by default, but
486        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
487        causes the error). The code is unchanged, but I tidied the documentation.
489    4.  Inside a character class, PCRE always treated \R and \X as literals,
490        whereas Perl faults them if its -w option is set. I have changed PCRE so
491        that it faults them when PCRE_EXTRA is set.
493    5.  Added support for \N, which always matches any character other than
494        newline. (It is the same as "." when PCRE_DOTALL is not set.)
496    6.  When compiling pcregrep with newer versions of gcc which may have
497        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
498        declared with attribute warn_unused_result" were given. Just casting the
499        result to (void) does not stop the warnings; a more elaborate fudge is
500        needed. I've used a macro to implement this.
502    7.  Minor change to pcretest.c to avoid a compiler warning.
504    8.  Added four artifical Unicode properties to help with an option to make
505        \s etc use properties (see next item). The new properties are: Xan
506        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
508    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
509        use Unicode properties. (*UCP) at the start of a pattern can be used to set
510        this option. Modified pcretest to add /W to test this facility. Added
511        REG_UCP to make it available via the POSIX interface.
513    10. Added --line-buffered to pcregrep.
515    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
516        studied, and the match started with a letter with a code point greater than
517        127 whose first byte was different to the first byte of the other case of
518        the letter, the other case of this starting letter was not recognized
519        (#976).
521    12. If a pattern that was studied started with a repeated Unicode property
522        test, for example, \p{Nd}+, there was the theoretical possibility of
523        setting up an incorrect bitmap of starting bytes, but fortunately it could
524        not have actually happened in practice until change 8 above was made (it
525        added property types that matched character-matching opcodes).
527    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
528        possible starting bytes for non-anchored patterns.
530    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
531        \R, and also a number of cases that involve Unicode properties, both
532        explicit and implicit when PCRE_UCP is set.
534    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
535        input, it could crash or give wrong results if characters with values
536        greater than 0xc0 were present in the subject string. (Detail: it assumed
537        UTF-8 input when processing these items.)
539    16. Added a lot of (int) casts to avoid compiler warnings in systems where
540        size_t is 64-bit (#991).
542    17. Added a check for running out of memory when PCRE is compiled with
543        --disable-stack-for-recursion (#990).
545    18. If the last data line in a file for pcretest does not have a newline on
546        the end, a newline was missing in the output.
548    19. The default pcre_chartables.c file recognizes only ASCII characters (values
549        less than 128) in its various bitmaps. However, there is a facility for
550        generating tables according to the current locale when PCRE is compiled. It
551        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
552        characters, are recognized by isspace() and therefore were getting set in
553        these tables, and indeed these tables seem to approximate to ISO 8859. This
554        caused a problem in UTF-8 mode when pcre_study() was used to create a list
555        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
556        which of course cannot start UTF-8 characters. I have changed the code so
557        that only real ASCII characters (less than 128) and the correct starting
558        bytes for UTF-8 encodings are set for characters greater than 127 when in
559        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
560        altogether.)
562    20. Added the /T option to pcretest so as to be able to run tests with non-
563        standard character tables, thus making it possible to include the tests
564        used for 19 above in the standard set of tests.
566    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
567        reference to a subpattern the other side of a comment that contains an
568        opening parenthesis caused either an internal compiling error, or a
569        reference to the wrong subpattern.
572    Version 8.02 19-Mar-2010
573    ------------------------
575    1.  The Unicode data tables have been updated to Unicode 5.2.0.
577    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
578        configured.
580    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
581        original author of that file, following a query about its status.
583    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
584        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
586    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
587        quantifier applied to a forward-referencing subroutine call, could compile
588        incorrect code or give the error "internal error: previously-checked
589        referenced subpattern not found".
591    6.  Both MS Visual Studio and Symbian OS have problems with initializing
592        variables to point to external functions. For these systems, therefore,
593        pcre_malloc etc. are now initialized to local functions that call the
594        relevant global functions.
596    7.  There were two entries missing in the vectors called coptable and poptable
597        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
598        I've fixed the data, and added a kludgy way of testing at compile time that
599        the lengths are correct (equal to the number of opcodes).
601    8.  Following on from 7, I added a similar kludge to check the length of the
602        eint vector in pcreposix.c.
604    9.  Error texts for pcre_compile() are held as one long string to avoid too
605        much relocation at load time. To find a text, the string is searched,
606        counting zeros. There was no check for running off the end of the string,
607        which could happen if a new error number was added without updating the
608        string.
610    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
612    11. \K was not working if it appeared in an atomic group or in a group that
613        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
614        \K is "not well defined" if used in an assertion. PCRE now accepts it if
615        the assertion is positive, but not if it is negative.
617    12. Change 11 fortuitously reduced the size of the stack frame used in the
618        "match()" function of pcre_exec.c by one pointer. Forthcoming
619        implementation of support for (*MARK) will need an extra pointer on the
620        stack; I have reserved it now, so that the stack frame size does not
621        decrease.
623    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
624        item in branch that calls a recursion is a subroutine call - as in the
625        second branch in the above example - was incorrectly given the compile-
626        time error "recursive call could loop indefinitely" because pcre_compile()
627        was not correctly checking the subroutine for matching a non-empty string.
629    14. The checks for overrunning compiling workspace could trigger after an
630        overrun had occurred. This is a "should never occur" error, but it can be
631        triggered by pathological patterns such as hundreds of nested parentheses.
632        The checks now trigger 100 bytes before the end of the workspace.
634    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
637    Version 8.01 19-Jan-2010
638    ------------------------
640    1.  If a pattern contained a conditional subpattern with only one branch (in
641        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
642        computed the wrong minimum data length (which is of course zero for such
643        subpatterns). This could cause incorrect "no match" results.
645    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
646        the pattern is reset in the first branch, pcre_compile() failed with
647        "internal error: code overflow at offset...". This happened only when
648        the reset was to the original external option setting. (An optimization
649        abstracts leading options settings into an external setting, which was the
650        cause of this.)
652    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
653        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
654        assertion pattern did not match (meaning that the assertion was true), it
655        was incorrectly treated as false if the SKIP had been reached during the
656        matching. This also applied to assertions used as conditions.
658    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
659        assertion subpattern, including such a pattern used as a condition,
660        unpredictable results occurred, instead of the error return
663    5.  The C++ GlobalReplace function was not working like Perl for the special
664        situation when an empty string is matched. It now does the fancy magic
665        stuff that is necessary.
667    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
668        removed. (These were left over from very, very early versions of PCRE.)
670    7.  Some cosmetic changes to the code to make life easier when compiling it
671        as part of something else:
673        (a) Change DEBUG to PCRE_DEBUG.
675        (b) In pcre_compile(), rename the member of the "branch_chain" structure
676            called "current" as "current_branch", to prevent a collision with the
677            Linux macro when compiled as a kernel module.
679        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
680            prevent a collision with the Linux macro when compiled as a kernel
681            module.
683    8.  In pcre_compile() there are some checks for integer overflows that used to
684        cast potentially large values to (double). This has been changed to that
685        when building, a check for int64_t is made, and if it is found, it is used
686        instead, thus avoiding the use of floating point arithmetic. (There is no
687        other use of FP in PCRE.) If int64_t is not found, the fallback is to
688        double.
690    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
691        2005 (difference between two addresses compared to an unsigned value).
693    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
694        custom one, because of the following reported problem in Windows:
696          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
697              under Win32.
698          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
699              therefore missing the function definition.
700          - The compiler thus generates a "C" signature for the test function.
701          - The linker fails to find the "C" function.
702          - PCRE fails to configure if asked to do so against libbz2.
704    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
705        messages were output:
707          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
708          rerunning libtoolize, to keep the correct libtool macros in-tree.
709          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
711        I have done both of these things.
713    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
714        most of the time, it *can* run out if it is given a pattern that contains a
715        runaway infinite recursion. I updated the discussion in the pcrestack man
716        page.
718    13. Now that we have gone to the x.xx style of version numbers, the minor
719        version may start with zero. Using 08 or 09 is a bad idea because users
720        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
721        interpreted as invalid octal numbers. I've updated the previous comment in
722        configure.ac, and also added a check that gives an error if 08 or 09 are
723        used.
725    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
726        causing partial matching to fail when the end of the subject matched \W
727        in a UTF-8 pattern where \W was quantified with a minimum of 3.
729    15. There were some discrepancies between the declarations in pcre_internal.h
730        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
731        their definitions. The declarations used "const uschar *" and the
732        definitions used USPTR. Even though USPTR is normally defined as "const
733        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
734        reported that: "This difference in casting confuses some C++ compilers, for
735        example, SunCC recognizes above declarations as different functions and
736        generates broken code for hbpcre." I have changed the declarations to use
737        USPTR.
739    16. GNU libtool is named differently on some systems. The autogen.sh script now
740        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
741        (FreeBSD).
743    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
744        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
745        comment: "Figure out how to create a longlong from a string: strtoll and
746        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
747        instance, but it only takes 2 args instead of 3!"
749    18. A subtle bug concerned with back references has been fixed by a change of
750        specification, with a corresponding code fix. A pattern such as
751        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
752        refers, was giving matches when it shouldn't. For example, xa=xaaa would
753        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
754        same bug. Such groups have to be quantified to be useful, or contained
755        inside another quantified group. (If there's no repetition, the reference
756        can never match.) The problem arises because, having left the group and
757        moved on to the rest of the pattern, a later failure that backtracks into
758        the group uses the captured value from the final iteration of the group
759        rather than the correct earlier one. I have fixed this in PCRE by forcing
760        any group that contains a reference to itself to be an atomic group; that
761        is, there cannot be any backtracking into it once it has completed. This is
762        similar to recursive and subroutine calls.
765    Version 8.00 19-Oct-09
766    ----------------------
768    1.  The table for translating pcre_compile() error codes into POSIX error codes
769        was out-of-date, and there was no check on the pcre_compile() error code
770        being within the table. This could lead to an OK return being given in
771        error.
773    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
774        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
775        in a Windows environment.
777    3.  The pcregrep --count option prints the count for each file even when it is
778        zero, as does GNU grep. However, pcregrep was also printing all files when
779        --files-with-matches was added. Now, when both options are given, it prints
780        counts only for those files that have at least one match. (GNU grep just
781        prints the file name in this circumstance, but including the count seems
782        more useful - otherwise, why use --count?) Also ensured that the
783        combination -clh just lists non-zero counts, with no names.
785    4.  The long form of the pcregrep -F option was incorrectly implemented as
786        --fixed_strings instead of --fixed-strings. This is an incompatible change,
787        but it seems right to fix it, and I didn't think it was worth preserving
788        the old behaviour.
790    5.  The command line items --regex=pattern and --regexp=pattern were not
791        recognized by pcregrep, which required --regex pattern or --regexp pattern
792        (with a space rather than an '='). The man page documented the '=' forms,
793        which are compatible with GNU grep; these now work.
795    6.  No libpcreposix.pc file was created for pkg-config; there was just
796        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
798    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
799        when UCP support is not needed, by modifying the Python script that
800        generates it from Unicode data files. This should not matter if the module
801        is correctly used as a library, but I received one complaint about 50K of
802        unwanted data. My guess is that the person linked everything into his
803        program rather than using a library. Anyway, it does no harm.
805    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
806        was a minimum greater than 1 for a wide character in a possessive
807        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
808        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
809        character. Chaos in the form of incorrect output or a compiling loop could
810        result.
812    9.  The restrictions on what a pattern can contain when partial matching is
813        requested for pcre_exec() have been removed. All patterns can now be
814        partially matched by this function. In addition, if there are at least two
815        slots in the offset vector, the offset of the earliest inspected character
816        for the match and the offset of the end of the subject are set in them when
817        PCRE_ERROR_PARTIAL is returned.
819    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
820        synonymous with PCRE_PARTIAL, for backwards compatibility, and
821        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
822        and may be more useful for multi-segment matching.
824    11. Partial matching with pcre_exec() is now more intuitive. A partial match
825        used to be given if ever the end of the subject was reached; now it is
826        given only if matching could not proceed because another character was
827        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
828        string "Z", which now yields "no match" instead of "partial match". In the
829        case of pcre_dfa_exec(), "no match" is given if every matching path for the
830        final character ended with (*FAIL).
832    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
833        if the pattern had a "must contain" character that was already found in the
834        earlier partial match, unless partial matching was again requested. For
835        example, with the pattern /dog.(body)?/, the "must contain" character is
836        "g". If the first part-match was for the string "dog", restarting with
837        "sbody" failed. This bug has been fixed.
839    13. The string returned by pcre_dfa_exec() after a partial match has been
840        changed so that it starts at the first inspected character rather than the
841        first character of the match. This makes a difference only if the pattern
842        starts with a lookbehind assertion or \b or \B (\K is not supported by
843        pcre_dfa_exec()). It's an incompatible change, but it makes the two
844        matching functions compatible, and I think it's the right thing to do.
846    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
847        so that the demonstration program is easily available in environments where
848        PCRE has not been installed from source.
850    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
851        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
852        library.
854    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
855        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
856        is not the first non-POSIX option to be added. Clearly some people find
857        these options useful.
859    17. If a caller to the POSIX matching function regexec() passes a non-zero
860        value for nmatch with a NULL value for pmatch, the value of
861        nmatch is forced to zero.
863    18. RunGrepTest did not have a test for the availability of the -u option of
864        the diff command, as RunTest does. It now checks in the same way as
865        RunTest, and also checks for the -b option.
867    19. If an odd number of negated classes containing just a single character
868        interposed, within parentheses, between a forward reference to a named
869        subpattern and the definition of the subpattern, compilation crashed with
870        an internal error, complaining that it could not find the referenced
871        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
872        [The bug was that it was starting one character too far in when skipping
873        over the character class, thus treating the ] as data rather than
874        terminating the class. This meant it could skip too much.]
876    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
877        /g option in pcretest when the pattern contains \K, which makes it possible
878        to have an empty string match not at the start, even when the pattern is
879        anchored. Updated pcretest and pcredemo to use this option.
881    21. If the maximum number of capturing subpatterns in a recursion was greater
882        than the maximum at the outer level, the higher number was returned, but
883        with unset values at the outer level. The correct (outer level) value is
884        now given.
886    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
887        PCRE did not set those parentheses (unlike Perl). I have now found a way to
888        make it do so. The string so far is captured, making this feature
889        compatible with Perl.
891    23. The tests have been re-organized, adding tests 11 and 12, to make it
892        possible to check the Perl 5.10 features against Perl 5.10.
894    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
895        pattern matches a fixed length string. PCRE did not allow this; now it
896        does. Neither allows recursion.
898    25. I finally figured out how to implement a request to provide the minimum
899        length of subject string that was needed in order to match a given pattern.
900        (It was back references and recursion that I had previously got hung up
901        on.) This code has now been added to pcre_study(); it finds a lower bound
902        to the length of subject needed. It is not necessarily the greatest lower
903        bound, but using it to avoid searching strings that are too short does give
904        some useful speed-ups. The value is available to calling programs via
905        pcre_fullinfo().
907    26. While implementing 25, I discovered to my embarrassment that pcretest had
908        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
909        study optimizations had never been tested with that matching function.
910        Oops. What is worse, even when it was passed study data, there was a bug in
911        pcre_dfa_exec() that meant it never actually used it. Double oops. There
912        were also very few tests of studied patterns with pcre_dfa_exec().
914    27. If (?| is used to create subpatterns with duplicate numbers, they are now
915        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
916        on the other side of the coin, they are no longer allowed to have different
917        names, because these cannot be distinguished in PCRE, and this has caused
918        confusion. (This is a difference from Perl.)
920    28. When duplicate subpattern names are present (necessarily with different
921        numbers, as required by 27 above), and a test is made by name in a
922        conditional pattern, either for a subpattern having been matched, or for
923        recursion in such a pattern, all the associated numbered subpatterns are
924        tested, and the overall condition is true if the condition is true for any
925        one of them. This is the way Perl works, and is also more like the way
926        testing by number works.
929    Version 7.9 11-Apr-09
930    ---------------------
932    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
933        (pcretest), all targets were linked against these libraries. This included
934        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
935        libraries. This caused unwanted dependencies to be created. This problem
936        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
937        pcretest is linked with readline.
939    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
940        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
941        moved outside it again, because FALSE and TRUE are already defined in AIX,
942        but BOOL is not.
944    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
945        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
947    4.  The pcregrep documentation said spaces were inserted as well as colons (or
948        hyphens) following file names and line numbers when outputting matching
949        lines. This is not true; no spaces are inserted. I have also clarified the
950        wording for the --colour (or --color) option.
952    5.  In pcregrep, when --colour was used with -o, the list of matching strings
953        was not coloured; this is different to GNU grep, so I have changed it to be
954        the same.
956    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
957        each matching line was coloured. Now it goes on to look for further matches
958        of any of the test patterns, which is the same behaviour as GNU grep.
960    7.  A pattern that could match an empty string could cause pcregrep to loop; it
961        doesn't make sense to accept an empty string match in pcregrep, so I have
962        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
963        seems to be how GNU grep behaves.
965    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
966        start or after a newline", because the conditional assertion was not being
967        correctly handled. The rule now is that both the assertion and what follows
968        in the first alternative must satisfy the test.
970    9.  If auto-callout was enabled in a pattern with a conditional group whose
971        condition was an assertion, PCRE could crash during matching, both with
972        pcre_exec() and pcre_dfa_exec().
974    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
975        used for matching.
977    11. Unicode property support in character classes was not working for
978        characters (bytes) greater than 127 when not in UTF-8 mode.
980    12. Added the -M command line option to pcretest.
982    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
984    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
986    16. Added comments and documentation about mis-use of no_arg in the C++
987        wrapper.
989    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
990        from Martin Jerabek that uses macro names for all relevant character and
991        string constants.
993    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
994        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
995        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
996        these, but not everybody uses configure.
998    19. A conditional group that had only one branch was not being correctly
999        recognized as an item that could match an empty string. This meant that an
1000        enclosing group might also not be so recognized, causing infinite looping
1001        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1002        with the subject "ab", where knowledge that the repeated group can match
1003        nothing is needed in order to break the loop.
1005    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1006        exec(), but without supplying a callout function, matching went wrong.
1008    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1009        leak if the size of the offset vector was greater than 30. When the vector
1010        is smaller, the saved offsets during recursion go onto a local stack
1011        vector, but for larger vectors malloc() is used. It was failing to free
1012        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1013        error, in fact).
1015    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1016        heapframe that is used only when UTF-8 support is enabled. This caused no
1017        problem, but was untidy.
1019    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1020        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1021        included within another project.
1023    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1024        slightly modified by me:
1026          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1027              not building pcregrep.
1029          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1030              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1032    25. Forward references, both numeric and by name, in patterns that made use of
1033        duplicate group numbers, could behave incorrectly or give incorrect errors,
1034        because when scanning forward to find the reference group, PCRE was not
1035        taking into account the duplicate group numbers. A pattern such as
1036        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1038    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1039        the feature of a custom pointer more persuasive (as requested by a user).
1041    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1042        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1043        pre-defined.
1045    28. Added support for (*UTF8) at the start of a pattern.
1047    29. Arrange for flags added by the "release type" setting in CMake to be shown
1048        in the configuration summary.
1051    Version 7.8 05-Sep-08
1052    ---------------------
1054    1.  Replaced UCP searching code with optimized version as implemented for Ad
1055        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1056        stage table and inline lookup instead of a function, giving speed ups of 2
1057        to 5 times on some simple patterns that I tested. Permission was given to
1058        distribute the MultiStage2.py script that generates the tables (it's not in
1059        the tarball, but is in the Subversion repository).
1061    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1062        scripts.
1064    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1065        a group with a zero qualifier. The result of the study could be incorrect,
1066        or the function might crash, depending on the pattern.
1068    4.  Caseless matching was not working for non-ASCII characters in back
1069        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1070        It now works when Unicode Property Support is available.
1072    5.  In pcretest, an escape such as \x{de} in the data was always generating
1073        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1074        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1075        truncation.
1077    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1079    7.  Added two (int) casts to pcregrep when printing the difference of two
1080        pointers, in case they are 64-bit values.
1082    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1083        test 2 if it fails.
1085    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1086        and a #define of that name to empty if it is not externally set. This is to
1087        allow users of MSVC to set it if necessary.
1089    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1090        the convenience functions in the pcre_get.c source file.
1092    11. An option change at the start of a pattern that had top-level alternatives
1093        could cause overwriting and/or a crash. This command provoked a crash in
1094        some environments:
1096          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1098        This potential security problem was recorded as CVE-2008-2371.
1100    12. For a pattern where the match had to start at the beginning or immediately
1101        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1102        pcre_dfa_exec() could read past the end of the passed subject if there was
1103        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1104        pcretest so that it places the subject at the end of its malloc-ed buffer.
1106    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1107        exec() might read past the end of the data buffer in UTF-8 mode.
1109    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1110        the data contained the byte 0x85 as part of a UTF-8 character within its
1111        first line. This applied both to normal and DFA matching.
1113    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1114        /^[^d]*?$/8 failed to match "abc".
1116    16. Added a missing copyright notice to pcrecpp_internal.h.
1118    17. Make it more clear in the documentation that values returned from
1119        pcre_exec() in ovector are byte offsets, not character counts.
1121    18. Tidied a few places to stop certain compilers from issuing warnings.
1123    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1124        supplied by Stefan Weber. I made a further small update for 7.8 because
1125        there is a change of source arrangements: the pcre_searchfuncs.c module is
1126        replaced by pcre_ucd.c.
1129    Version 7.7 07-May-08
1130    ---------------------
1132    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1133        a string to a long long, pretend we don't even have a long long." This is
1134        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1136    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1137        pre-7.6 versions, which defined a global no_arg variable instead of putting
1138        it in the RE class. (See also #8 below.)
1140    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1141        Lopes.
1143    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1145        (1) The include/exclude patterns were being applied to the whole pathnames
1146            of files, instead of just to the final components.
1148        (2) If there was more than one level of directory, the subdirectories were
1149            skipped unless they satisfied the include/exclude conditions. This is
1150            inconsistent with GNU grep (and could even be seen as contrary to the
1151            pcregrep specification - which I improved to make it absolutely clear).
1152            The action now is always to scan all levels of directory, and just
1153            apply the include/exclude patterns to regular files.
1155    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1156        --exclude_dir in the tests to avoid scanning .svn directories.
1158    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1159        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1160        doesn't support NULs in patterns.
1162    7.  Added some missing "const"s to declarations of static tables in
1163        pcre_compile.c and pcre_dfa_exec.c.
1165    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1166        caused by fix #2  above. (Subsequently also a second patch to fix the
1167        first patch. And a third patch - this was a messy problem.)
1169    9.  Applied Craig's patch to remove the use of push_back().
1171    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1172        matching function regexec().
1174    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1175        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1176        references. PCRE supports relative numbers with this syntax (I don't think
1177        Oniguruma does).
1179    12. Previously, a group with a zero repeat such as (...){0} was completely
1180        omitted from the compiled regex. However, this means that if the group
1181        was called as a subroutine from elsewhere in the pattern, things went wrong
1182        (an internal error was given). Such groups are now left in the compiled
1183        pattern, with a new opcode that causes them to be skipped at execution
1184        time.
1186    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1187        to the way PCRE behaves:
1189        (a) A lone ] character is dis-allowed (Perl treats it as data).
1191        (b) A back reference to an unmatched subpattern matches an empty string
1192            (Perl fails the current match path).
1194        (c) A data ] in a character class must be notated as \] because if the
1195            first data character in a class is ], it defines an empty class. (In
1196            Perl it is not possible to have an empty class.) The empty class []
1197            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1198            The negative empty class [^] matches any one character, independently
1199            of the DOTALL setting.
1201    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1202        non-existent subpattern following a character class starting with ']' and
1203        containing () gave an internal compiling error instead of "reference to
1204        non-existent subpattern". Fortunately, when the pattern did exist, the
1205        compiled code was correct. (When scanning forwards to check for the
1206        existencd of the subpattern, it was treating the data ']' as terminating
1207        the class, so got the count wrong. When actually compiling, the reference
1208        was subsequently set up correctly.)
1210    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1211        it was being rejected as not supported by pcre_dfa_exec(), even though
1212        other assertions are supported. I have made pcre_dfa_exec() support
1213        (*FAIL).
1215    16. The implementation of 13c above involved the invention of a new opcode,
1216        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1217        cannot be changed at match time, I realized I could make a small
1218        improvement to matching performance by compiling OP_ALLANY instead of
1219        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1220        on the OP_ANY path.
1222    17. Compiling pcretest on Windows with readline support failed without the
1223        following two fixes: (1) Make the unistd.h include conditional on
1224        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1226    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1227        ncurses library to be included for pcretest when ReadLine support is
1228        requested, but also to allow for it to be overridden. This patch came from
1229        Daniel Bergström.
1231    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1232        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1233        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1234        spotting this.
1237    Version 7.6 28-Jan-08
1238    ---------------------
1240    1.  A character class containing a very large number of characters with
1241        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1242        overflow.
1244    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1245        HAVE_LONG_LONG is not defined.
1247    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1248        bring them up to date and include new features. This patch includes:
1250        - Fixed PH's badly added libz and libbz2 support.
1251        - Fixed a problem with static linking.
1252        - Added pcredemo. [But later removed - see 7 below.]
1253        - Fixed dftables problem and added an option.
1254        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1255            HAVE_LONG_LONG.
1256        - Added readline support for pcretest.
1257        - Added an listing of the option settings after cmake has run.
1259    4.  A user submitted a patch to Makefile that makes it easy to create
1260        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1261        Makefile.am that cause it to include this special target, without
1262        affecting anything else. Note that the same mingw target plus all
1263        the other distribution libraries and programs are now supported
1264        when configuring with CMake (see 6 below) instead of with
1265        Configure/Make.
1267    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1268        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1269        exported in the Windows port". It has not yet been confirmed that the patch
1270        solves the problem, but it does no harm.
1272    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1273        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1274        with CMake, and also correct the comment about stack recursion.
1276    7.  Remove the automatic building of pcredemo from the ./configure system and
1277        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1278        of a program that users should build themselves after PCRE is installed, so
1279        building it automatically is not really right. What is more, it gave
1280        trouble in some build environments.
1282    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1285    Version 7.5 10-Jan-08
1286    ---------------------
1288    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1289        values in parens when parsing an RE using the C++ wrapper."
1291    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1292        Characters greater than 255 were excluded from the class instead of being
1293        included.
1295    3.  The same bug as (2) above applied to negated POSIX classes such as
1296        [:^space:].
1298    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1299        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1300        I have changed it.
1302    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1303        first named subpattern) and a construct such as (?&a) would reference the
1304        first named subpattern whose name started with "a" (in other words, the
1305        length check was missing). Both these problems are fixed. "Subpattern name
1306        expected" is now given for (?&) (a zero-length name), and this patch also
1307        makes it give the same error for \k'' (previously it complained that that
1308        was a reference to a non-existent subpattern).
1310    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1311        this is right because (?- can be followed by option settings as well as by
1312        digits. I have, however, made the messages clearer.
1314    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1315        than the number used in the conditional) now cause a compile-time error.
1316        This is actually not compatible with Perl, which accepts such patterns, but
1317        treats the conditional as always being FALSE (as PCRE used to), but it
1318        seems to me that giving a diagnostic is better.
1320    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1321        and messages.
1323    9.  Fix two occurrences of "backslash" in comments that should have been
1324        "backspace".
1326    10. Remove two redundant lines of code that can never be obeyed (their function
1327        was moved elsewhere).
1329    11. The program that makes PCRE's Unicode character property table had a bug
1330        which caused it to generate incorrect table entries for sequences of
1331        characters that have the same character type, but are in different scripts.
1332        It amalgamated them into a single range, with the script of the first of
1333        them. In other words, some characters were in the wrong script. There were
1334        thirteen such cases, affecting characters in the following ranges:
1336          U+002b0 - U+002c1
1337          U+0060c - U+0060d
1338          U+0061e - U+00612
1339          U+0064b - U+0065e
1340          U+0074d - U+0076d
1341          U+01800 - U+01805
1342          U+01d00 - U+01d77
1343          U+01d9b - U+01dbf
1344          U+0200b - U+0200f
1345          U+030fc - U+030fe
1346          U+03260 - U+0327f
1347          U+0fb46 - U+0fbb1
1348          U+10450 - U+1049d
1350    12. The -o option (show only the matching part of a line) for pcregrep was not
1351        compatible with GNU grep in that, if there was more than one match in a
1352        line, it showed only the first of them. It now behaves in the same way as
1353        GNU grep.
1355    13. If the -o and -v options were combined for pcregrep, it printed a blank
1356        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1357        does the same. The return code can be used to tell if there were any
1358        non-matching lines.
1360    14. Added --file-offsets and --line-offsets to pcregrep.
1362    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1363        infinitely looping recursion. The bug was that positive lookaheads were not
1364        being skipped when checking for a possible empty match (negative lookaheads
1365        and both kinds of lookbehind were skipped).
1367    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1368        inclusion of <windows.h> to before rather than after the definition of
1369        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1371    17. Specifying a possessive quantifier with a specific limit for a Unicode
1372        character property caused pcre_compile() to compile bad code, which led at
1373        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1374        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1375        caused the error; without that there was no problem.
1377    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1379    19. Added --enable-pcretest-libreadline.
1381    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1382        RE::GlobalReplace(). As a result, the number of replacements returned was
1383        double what it should be. I removed one of the increments, but Craig sent a
1384        later patch that removed the other one (the right fix) and added unit tests
1385        that check the return values (which was not done before).
1387    21. Several CMake things:
1389        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1390            the names libpcre and libpcreposix, not just pcre and pcreposix.
1392        (2) The above change means that pcretest and pcregrep are now correctly
1393            linked with the newly-built libraries, not previously installed ones.
1397    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1398        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1399        UTF-8 newline character). The key issue is that the pattern starts .*;
1400        this means that the match must be either at the beginning, or after a
1401        newline. The bug was in the code for advancing after a failed match and
1402        checking that the new position followed a newline. It was not taking
1403        account of UTF-8 characters correctly.
1405    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1406        character classes. PCRE was not treating the sequence [:...:] as a
1407        character class unless the ... were all letters. Perl, however, seems to
1408        allow any characters between [: and :], though of course it rejects as
1409        unknown any "names" that contain non-letters, because all the known class
1410        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1411        for example, whereas PCRE did not - it did not recognize a POSIX character
1412        class. This seemed a bit dangerous, so the code has been changed to be
1413        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1414        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1415        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1416        Perl does, and where it didn't before.
1418    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1419        Windows environments %n is disabled by default.
1422    Version 7.4 21-Sep-07
1423    ---------------------
1425    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1426        means that a class such as [\s] counted as "explicit reference to CR or
1427        LF". That isn't really right - the whole point of the change was to try to
1428        help when there was an actual mention of one of the two characters. So now
1429        the change happens only if \r or \n (or a literal CR or LF) character is
1430        encountered.
1432    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1433        of both had grown to the point where there were only 3 bits left.
1434        Fortunately, there was spare space in the data structure, and so I have
1435        moved the internal flags into a new 16-bit field to free up more option
1436        bits.
1438    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1439        but did not set the internal JCHANGED flag - either of these is enough to
1440        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1441        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1442        start sets both bits.
1444    4.  Added options (at build time, compile time, exec time) to change \R from
1445        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1447    5.  doc/pcresyntax.html was missing from the distribution.
1449    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1450        compatibility, even though it is no longer used.
1452    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1453        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1454        windows.h file is present (where different names are used). [This was
1455        reversed later after testing - see 16 below.]
1457    8.  Changed all #include <config.h> to #include "config.h". There were also
1458        some further <pcre.h> cases that I changed to "pcre.h".
1460    9.  When pcregrep was used with the --colour option, it missed the line ending
1461        sequence off the lines that it output.
1463    10. It was pointed out to me that arrays of string pointers cause lots of
1464        relocations when a shared library is dynamically loaded. A technique of
1465        using a single long string with a table of offsets can drastically reduce
1466        these. I have refactored PCRE in four places to do this. The result is
1467        dramatic:
1469          Originally:                          290
1470          After changing UCP table:            187
1471          After changing error message table:   43
1472          After changing table of "verbs"       36
1473          After changing table of Posix names   22
1475        Thanks to the folks working on Gregex for glib for this insight.
1477    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1478        unicode-properties was also set.
1480    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1482    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1483        checked only for CRLF.
1485    14. Added casts to pcretest.c to avoid compiler warnings.
1487    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1489    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1490        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1491        entirely. This removes changes made in 7 above.
1493    17. The CMake files have been updated, and there is now more information about
1494        building with CMake in the NON-UNIX-USE document.
1497    Version 7.3 28-Aug-07
1498    ---------------------
1500     1. In the rejigging of the build system that eventually resulted in 7.1, the
1501        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1502        brackets there is not right, since it causes compilers to look for an
1503        installed pcre.h, not the version that is in the source that is being
1504        compiled (which of course may be different). I have changed it back to:
1506          #include "pcre.h"
1508        I have a vague recollection that the change was concerned with compiling in
1509        different directories, but in the new build system, that is taken care of
1510        by the VPATH setting the Makefile.
1512     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1513        when the subject happened to end in the byte 0x85 (e.g. if the last
1514        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1515        characters but of course it shouldn't be taken as a newline when it is part
1516        of another character. The bug was that, for an unlimited repeat of . in
1517        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1518        characters when looking for a newline.
1520     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1522     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1523        in debug output.
1525     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1526        long printing in the pcrecpp unittest when running under MinGW.
1528     6. ESC_K was left out of the EBCDIC table.
1530     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1531        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1532        limit also applies to "virtual nesting" when a pattern is recursive, and in
1533        this case 1000 isn't so big. I have been able to remove this limit at the
1534        expense of backing off one optimization in certain circumstances. Normally,
1535        when pcre_exec() would call its internal match() function recursively and
1536        immediately return the result unconditionally, it uses a "tail recursion"
1537        feature to save stack. However, when a subpattern that can match an empty
1538        string has an unlimited repetition quantifier, it no longer makes this
1539        optimization. That gives it a stack frame in which to save the data for
1540        checking that an empty string has been matched. Previously this was taken
1541        from the 1000-entry workspace that had been reserved. So now there is no
1542        explicit limit, but more stack is used.
1544     8. Applied Daniel's patches to solve problems with the import/export magic
1545        syntax that is required for Windows, and which was going wrong for the
1546        pcreposix and pcrecpp parts of the library. These were overlooked when this
1547        problem was solved for the main library.
1549     9. There were some crude static tests to avoid integer overflow when computing
1550        the size of patterns that contain repeated groups with explicit upper
1551        limits. As the maximum quantifier is 65535, the maximum group length was
1552        set at 30,000 so that the product of these two numbers did not overflow a
1553        32-bit integer. However, it turns out that people want to use groups that
1554        are longer than 30,000 bytes (though not repeat them that many times).
1555        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1556        made it possible to implement the integer overflow checks in a much more
1557        dynamic way, which I have now done. The artificial limitation on group
1558        length has been removed - we now have only the limit on the total length of
1559        the compiled pattern, which depends on the LINK_SIZE setting.
1561    10. Fixed a bug in the documentation for get/copy named substring when
1562        duplicate names are permitted. If none of the named substrings are set, the
1563        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1564        empty string.
1566    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1567        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1568        because the ] is interpreted as the first data character and the
1569        terminating ] is not found. PCRE has been made compatible with Perl in this
1570        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1571        cause memory overwriting.
1573    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1574        string has been matched (to stop an infinite loop). It was not recognizing
1575        a conditional subpattern that could match an empty string if that
1576        subpattern was within another subpattern. For example, it looped when
1577        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1578        condition was not nested. This bug has been fixed.
1580    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1581        past the start of the subject in the presence of bytes with the top bit
1582        set, for example "\x8aBCD".
1584    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1585        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1587    14. Optimized (?!) to (*FAIL).
1589    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1590        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1591        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1592        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1593        does: it's just the validity check that is more restrictive.
1595    16. Inserted checks for integer overflows during escape sequence (backslash)
1596        processing, and also fixed erroneous offset values for syntax errors during
1597        backslash processing.
1599    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1600        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1602    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1603        caused an overrun.
1605    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1606        something other than just ASCII characters) inside a group that had an
1607        unlimited repeat caused a loop at compile time (while checking to see
1608        whether the group could match an empty string).
1610    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1611        [\P{Any}] did so. (Error in the code for printing property names.)
1613    21. An orphan \E inside a character class could cause a crash.
1615    22. A repeated capturing bracket such as (A)? could cause a wild memory
1616        reference during compilation.
1618    23. There are several functions in pcre_compile() that scan along a compiled
1619        expression for various reasons (e.g. to see if it's fixed length for look
1620        behind). There were bugs in these functions when a repeated \p or \P was
1621        present in the pattern. These operators have additional parameters compared
1622        with \d, etc, and these were not being taken into account when moving along
1623        the compiled data. Specifically:
1625        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1626            length.
1628        (b) An item such as \pL+ within a repeated group could cause crashes or
1629            loops.
1631        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1632            "reference to non-existent subpattern" error.
1634        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1636    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1637        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1639    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1641    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1642        character were causing crashes (broken optimization).
1644    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1645        \p or \P) caused a compile-time loop.
1647    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1648        break. For example, the unstudied pattern [\r\n]A does not match the string
1649        "\r\nA" because change 7.0/46 below moves the current point on by two
1650        characters after failing to match at the start. However, the pattern \nA
1651        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1652        the same is true. There doesn't seem any very clean way out of this, but
1653        what I have chosen to do makes the common cases work: PCRE now takes note
1654        of whether there can be an explicit match for \r or \n anywhere in the
1655        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1656        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1657        pattern has explicit CR or LF references.
1659    29. Added (*CR) etc for changing newline setting at start of pattern.
1662    Version 7.2 19-Jun-07
1663    ---------------------
1665     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1666        which is apparently normally available under Windows.
1668     2. Re-jig the pcregrep tests with different newline settings in an attempt
1669        to make them independent of the local environment's newline setting.
1671     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1673     4. Some of the "internals" tests were previously cut out when the link size
1674        was not 2, because the output contained actual offsets. The recent new
1675        "Z" feature of pcretest means that these can be cut out, making the tests
1676        usable with all link sizes.
1678     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1679        stack recursion. This gives a massive performance boost under BSD, but just
1680        a small improvement under Linux. However, it saves one field in the frame
1681        in all cases.
1683     6. Added more features from the forthcoming Perl 5.10:
1685        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1686            recursion call. It refers to the nth most recently opened parentheses.
1688        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1689            to be opened parentheses.
1691        (c) Conditions that refer to capturing parentheses can be specified
1692            relatively, for example, (?(-2)... or (?(+3)...
1694        (d) \K resets the start of the current match so that everything before
1695            is not part of it.
1697        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1699        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1700            reference syntax.
1702        (g) (?| introduces a group in which the numbering of parentheses in each
1703            alternative starts with the same number.
1705        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1707     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1710     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1711        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1712        for detecting groups that can match an empty string.
1714     9. A pattern with a very large number of alternatives (more than several
1715        hundred) was running out of internal workspace during the pre-compile
1716        phase, where pcre_compile() figures out how much memory will be needed. A
1717        bit of new cunning has reduced the workspace needed for groups with
1718        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1719        workspace instead of running out of the 4096 that are available.
1721    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1723    11. Applied patch from Google to remove an optimization that didn't quite work.
1724        The report of the bug said:
1726          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1727          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1728          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1730    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1731        it matched the wrong number of bytes.
1734    Version 7.1 24-Apr-07
1735    ---------------------
1737     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1738        that is more "standard", making use of automake and other Autotools. There
1739        is some re-arrangement of the files and adjustment of comments consequent
1740        on this.
1742     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1743        for recursive directory scanning broke on some systems because the files
1744        are not scanned in any specific order and on different systems the order
1745        was different. A call to "sort" has been inserted into RunGrepTest for the
1746        approprate test as a short-term fix. In the longer term there may be an
1747        alternative.
1749     3. I had an email from Eric Raymond about problems translating some of PCRE's
1750        man pages to HTML (despite the fact that I distribute HTML pages, some
1751        people do their own conversions for various reasons). The problems
1752        concerned the use of low-level troff macros .br and .in. I have therefore
1753        removed all such uses from the man pages (some were redundant, some could
1754        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1755        HTML has been updated to handle .nf/.fi and to complain if it encounters
1756        .br or .in.
1758     4. Updated comments in configure.ac that get placed in config.h.in and also
1759        arranged for config.h to be included in the distribution, with the name
1760        config.h.generic, for the benefit of those who have to compile without
1761        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1763     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1764        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1765        makevp.bat for the current PCRE, using the additional files
1766        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1768     6. A Windows user reported a minor discrepancy with test 2, which turned out
1769        to be caused by a trailing space on an input line that had got lost in his
1770        copy. The trailing space was an accident, so I've just removed it.
1772     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1773        that is needed.
1775     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1776        as "const" (a) because they are and (b) because it helps the PHP
1777        maintainers who have recently made a script to detect big data structures
1778        in the php code that should be moved to the .rodata section. I remembered
1779        to update Builducptable as well, so it won't revert if ucptable.h is ever
1780        re-created.
1782     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1783        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1784        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1785        support is not required. This saves 1.5-2K of code, which is important in
1786        some applications.
1788        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1789        so as not to refer to the tables, even though these functions will never be
1790        called when UTF-8 support is disabled. Otherwise there are problems with a
1791        shared library.
1793    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1795        (a) It was defining its arguments as char * instead of void *.
1797        (b) It was assuming that all moves were upwards in memory; this was true
1798            a long time ago when I wrote it, but is no longer the case.
1800        The emulated memove() is provided for those environments that have neither
1801        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1802        is clearly not the case, as these two bugs were recently reported.
1804    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1805        and Detrail to create the HTML documentation, the .txt form of the man
1806        pages, and it removes trailing spaces from listed files. It also creates
1807        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1808        case, it wraps all the #defines with #ifndefs. This script should be run
1809        before "make dist".
1811    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1812        with Unicode property support.
1814        (a) For a maximizing quantifier, if the two different cases of the
1815            character were of different lengths in their UTF-8 codings (there are
1816            some cases like this - I found 11), and the matching function had to
1817            back up over a mixture of the two cases, it incorrectly assumed they
1818            were both the same length.
1820        (b) When PCRE was configured to use the heap rather than the stack for
1821            recursion during matching, it was not correctly preserving the data for
1822            the other case of a UTF-8 character when checking ahead for a match
1823            while processing a minimizing repeat. If the check also involved
1824            matching a wide character, but failed, corruption could cause an
1825            erroneous result when trying to check for a repeat of the original
1826            character.
1828    13. Some tidying changes to the testing mechanism:
1830        (a) The RunTest script now detects the internal link size and whether there
1831            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1832            values substituted by "configure". (The RunGrepTest script already did
1833            this for UTF-8.) The configure.ac script no longer substitutes the
1834            relevant variables.
1836        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1837            with length and offset values. This means that the output is different
1838            for different internal link sizes. Test 2 is skipped for link sizes
1839            other than 2 because of this, bypassing the problem. Unfortunately,
1840            there was also a test in test 3 (the locale tests) that used /B and
1841            failed for link sizes other than 2. Rather than cut the whole test out,
1842            I have added a new /Z option to pcretest that replaces the length and
1843            offset values with spaces. This is now used to make test 3 independent
1844            of link size. (Test 2 will be tidied up later.)
1846    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1847        segmentation fault instead of returning the appropriate error message.
1849    15. In multiline mode when the newline sequence was set to "any", the pattern
1850        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1851        This doesn't seem right; it now treats the CRLF combination as the line
1852        ending, and so does not match in that case. It's only a pattern such as ^$
1853        that would hit this one: something like ^ABC$ would have failed after \r
1854        and then tried again after \r\n.
1856    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1857        in an attempt to make files that differ only in their line terminators
1858        compare equal. This works on Linux.
1860    17. Under certain error circumstances pcregrep might try to free random memory
1861        as it exited. This is now fixed, thanks to valgrind.
1863    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1864        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1865        was because its rules for how to advance for /g after matching an empty
1866        string at the end of a line did not allow for this case. They now check for
1867        it specially.
1869    20. pcretest is supposed to handle patterns and data of any length, by
1870        extending its buffers when necessary. It was getting this wrong when the
1871        buffer for a data line had to be extended.
1873    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1874        CRLF as a newline sequence.
1876    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1877        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1878        I have nevertheless tidied it up.
1880    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1882    24. Added a man page for pcre-config.
1885    Version 7.0 19-Dec-06
1886    ---------------------
1888     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1889        moving to gcc 4.1.1.
1891     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1892        sys/time.h, which is documented as needed for this function. It doesn't
1893        seem to matter on Linux, but it showed up on some releases of OS X.
1895     3. It seems that there are systems where bytes whose values are greater than
1896        127 match isprint() in the "C" locale. The "C" locale should be the
1897        default when a C program starts up. In most systems, only ASCII printing
1898        characters match isprint(). This difference caused the output from pcretest
1899        to vary, making some of the tests fail. I have changed pcretest so that:
1901        (a) When it is outputting text in the compiled version of a pattern, bytes
1902            other than 32-126 are always shown as hex escapes.
1904        (b) When it is outputting text that is a matched part of a subject string,
1905            it does the same, unless a different locale has been set for the match
1906            (using the /L modifier). In this case, it uses isprint() to decide.
1908     4. Fixed a major bug that caused incorrect computation of the amount of memory
1909        required for a compiled pattern when options that changed within the
1910        pattern affected the logic of the preliminary scan that determines the
1911        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1912        that the computed length was too small. The symptoms of this bug were
1913        either the PCRE error "internal error: code overflow" from pcre_compile(),
1914        or a glibc crash with a message such as "pcretest: free(): invalid next
1915        size (fast)". Examples of patterns that provoked this bug (shown in
1916        pcretest format) are:
1918          /(?-x: )/x
1919          /(?x)(?-x: \s*#\s*)/
1920          /((?i)[\x{c0}])/8
1921          /(?i:[\x{c0}])/8
1923        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1924        is now done differently.
1926     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1927        wrapper classes; (b) implement a new function in the C++ scanner that is
1928        more efficient than the old way of doing things because it avoids levels of
1929        recursion in the regex matching; (c) add a paragraph to the documentation
1930        for the FullMatch() function.
1932     6. The escape sequence \n was being treated as whatever was defined as
1933        "newline". Not only was this contrary to the documentation, which states
1934        that \n is character 10 (hex 0A), but it also went horribly wrong when
1935        "newline" was defined as CRLF. This has been fixed.
1937     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1938        was being set to -1 for the "end of line" case (supposedly a value that no
1939        character can have). Though this value is never used (the check for end of
1940        line is "zero bytes in current character"), it caused compiler complaints.
1941        I've changed it to 0xffffffff.
1943     8. In pcre_version.c, the version string was being built by a sequence of
1944        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1945        string (as it is for production releases) called a macro with an empty
1946        argument. The C standard says the result of this is undefined. The gcc
1947        compiler treats it as an empty string (which was what was wanted) but it is
1948        reported that Visual C gives an error. The source has been hacked around to
1949        avoid this problem.
1951     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1952        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1953        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1954        of them did).
1956    10. Originally, pcretest opened its input and output without "b"; then I was
1957        told that "b" was needed in some environments, so it was added for release
1958        5.0 to both the input and output. (It makes no difference on Unix-like
1959        systems.) Later I was told that it is wrong for the input on Windows. I've
1960        now abstracted the modes into two macros, to make it easier to fiddle with
1961        them, and removed "b" from the input mode under Windows.
1963    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1965    12. Added -help and --help to pcretest as an official way of being reminded
1966        of the options.
1968    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1969        and pcrecpp.cc because they annoy compilers at high warning levels.
1971    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1973    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1974        scripts are not C programs :-) and which was not noticed because it works
1975        on Linux.
1977    16. pcretest is supposed to handle any length of pattern and data line (as one
1978        line or as a continued sequence of lines) by extending its input buffer if
1979        necessary. This feature was broken for very long pattern lines, leading to
1980        a string of junk being passed to pcre_compile() if the pattern was longer
1981        than about 50K.
1983    17. I have done a major re-factoring of the way pcre_compile() computes the
1984        amount of memory needed for a compiled pattern. Previously, there was code
1985        that made a preliminary scan of the pattern in order to do this. That was
1986        OK when PCRE was new, but as the facilities have expanded, it has become
1987        harder and harder to keep it in step with the real compile phase, and there
1988        have been a number of bugs (see for example, 4 above). I have now found a
1989        cunning way of running the real compile function in a "fake" mode that
1990        enables it to compute how much memory it would need, while actually only
1991        ever using a few hundred bytes of working memory and without too many
1992        tests of the mode. This should make future maintenance and development
1993        easier. A side effect of this work is that the limit of 200 on the nesting
1994        depth of parentheses has been removed (though this was never a serious
1995        limitation, I suspect). However, there is a downside: pcre_compile() now
1996        runs more slowly than before (30% or more, depending on the pattern). I
1997        hope this isn't a big issue. There is no effect on runtime performance.
1999    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2000        newline (only possible for the last line of a file) and it was a
2001        pattern that set a locale (followed by /Lsomething), pcretest crashed.
2003    19. Added additional timing features to pcretest. (1) The -tm option now times
2004        matching only, not compiling. (2) Both -t and -tm can be followed, as a
2005        separate command line item, by a number that specifies the number of
2006        repeats to use when timing. The default is 50000; this gives better
2007        precision, but takes uncomfortably long for very large patterns.
2009    20. Extended pcre_study() to be more clever in cases where a branch of a
2010        subpattern has no definite first character. For example, (a*|b*)[cd] would
2011        previously give no result from pcre_study(). Now it recognizes that the
2012        first character must be a, b, c, or d.
2014    21. There was an incorrect error "recursive call could loop indefinitely" if
2015        a subpattern (or the entire pattern) that was being tested for matching an
2016        empty string contained only one non-empty item after a nested subpattern.
2017        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2018        incorrectly, because the \d was being skipped in the check.
2020    22. The pcretest program now has a new pattern option /B and a command line
2021        option -b, which is equivalent to adding /B to every pattern. This causes
2022        it to show the compiled bytecode, without the additional information that
2023        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2024        is the same as /B/I).
2026    23. A new optimization is now able automatically to treat some sequences such
2027        as a*b as a*+b. More specifically, if something simple (such as a character
2028        or a simple class like \d) has an unlimited quantifier, and is followed by
2029        something that cannot possibly match the quantified thing, the quantifier
2030        is automatically "possessified".
2032    24. A recursive reference to a subpattern whose number was greater than 39
2033        went wrong under certain circumstances in UTF-8 mode. This bug could also
2034        have affected the operation of pcre_study().
2036    25. Realized that a little bit of performance could be had by replacing
2037        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2039    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2041    27. Possessive quantifiers such as a++ were previously implemented by turning
2042        them into atomic groups such as ($>a+). Now they have their own opcodes,
2043        which improves performance. This includes the automatically created ones
2044        from 23 above.
2046    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2047        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2048        the first matched character to be a colon. This applied both to named and
2049        numbered groups.
2051    29. The ucpinternal.h header file was missing its idempotency #ifdef.
2053    30. I was sent a "project" file called libpcre.a.dev which I understand makes
2054        building PCRE on Windows easier, so I have included it in the distribution.
2056    31. There is now a check in pcretest against a ridiculously large number being
2057        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2058        loop, the loop is abandoned.
2060    32. Forward references to subpatterns in conditions such as (?(2)...) where
2061        subpattern 2 is defined later cause pcre_compile() to search forwards in
2062        the pattern for the relevant set of parentheses. This search went wrong
2063        when there were unescaped parentheses in a character class, parentheses
2064        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2066    33. "Subroutine" calls and backreferences were previously restricted to
2067        referencing subpatterns earlier in the regex. This restriction has now
2068        been removed.
2070    34. Added a number of extra features that are going to be in Perl 5.10. On the
2071        whole, these are just syntactic alternatives for features that PCRE had
2072        previously implemented using the Python syntax or my own invention. The
2073        other formats are all retained for compatibility.
2075        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2076            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2077            also .NET compatible.
2079        (b) A recursion or subroutine call to a named group can now be defined as
2080            (?&name) as well as (?P>name).
2082        (c) A backreference to a named group can now be defined as \k<name> or
2083            \k'name' as well as (?P=name). The new forms, as well as being in Perl
2084            5.10, are also .NET compatible.
2086        (d) A conditional reference to a named group can now use the syntax
2087            (?(<name>) or (?('name') as well as (?(name).
2089        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2090            groups (named and numbered) that are never evaluated inline, but can be
2091            called as "subroutines" from elsewhere. In effect, the DEFINE condition
2092            is always false. There may be only one alternative in such a group.
2094        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2095            as the simple (?(R). The condition is true only if the most recent
2096            recursion is that of the given number or name. It does not search out
2097            through the entire recursion stack.
2099        (g) The escape \gN or \g{N} has been added, where N is a positive or
2100            negative number, specifying an absolute or relative reference.
2102    35. Tidied to get rid of some further signed/unsigned compiler warnings and
2103        some "unreachable code" warnings.
2105    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2106        things, this adds five new scripts.
2108    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2109        There were also incompatibilities regarding the handling of \Q..\E inside
2110        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2111        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2113    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2114        matches an empty string, and forcibly breaks the loop. There were bugs in
2115        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
2116        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
2117        separate and independent bugs (that affected different cases) have been
2118        fixed.
2120    39. Refactored the code to abolish the use of different opcodes for small
2121        capturing bracket numbers. This is a tidy that I avoided doing when I
2122        removed the limit on the number of capturing brackets for 3.5 back in 2001.
2123        The new approach is not only tidier, it makes it possible to reduce the
2124        memory needed to fix the previous bug (38).
2126    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2127        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2128        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2129        mode.
2131    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2132        report.
2134    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2135        copy construction and assignment in the C++ wrapper.
2137    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2138        couple of bugs that could have given wrong results in the "--newline=crlf"
2139        case.
2141    44. Added a number of casts and did some reorganization of signed/unsigned int
2142        variables following suggestions from Dair Grant. Also renamed the variable
2143        "this" as "item" because it is a C++ keyword.
2145    45. Arranged for dftables to add
2147          #include "pcre_internal.h"
2149        to pcre_chartables.c because without it, gcc 4.x may remove the array
2150        definition from the final binary if PCRE is built into a static library and
2151        dead code stripping is activated.
2153    46. For an unanchored pattern, if a match attempt fails at the start of a
2154        newline sequence, and the newline setting is CRLF or ANY, and the next two
2155        characters are CRLF, advance by two characters instead of one.
2158    Version 6.7 04-Jul-06
2159    ---------------------
2161     1. In order to handle tests when input lines are enormously long, pcretest has
2162        been re-factored so that it automatically extends its buffers when
2163        necessary. The code is crude, but this _is_ just a test program. The
2164        default size has been increased from 32K to 50K.
2166     2. The code in pcre_study() was using the value of the re argument before
2167        testing it for NULL. (Of course, in any sensible call of the function, it
2168        won't be NULL.)
2170     3. The memmove() emulation function in pcre_internal.h, which is used on
2171        systems that lack both memmove() and bcopy() - that is, hardly ever -
2172        was missing a "static" storage class specifier.
2174     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2175        containing an extended class (one that cannot be represented by a bitmap
2176        because it contains high-valued characters or Unicode property items, e.g.
2177        [\pZ]). Almost always one would set UTF-8 mode when processing such a
2178        pattern, but PCRE should not loop if you do not (it no longer does).
2179        [Detail: two cases were found: (a) a repeated subpattern containing an
2180        extended class; (b) a recursive reference to a subpattern that followed a
2181        previous extended class. It wasn't skipping over the extended class
2182        correctly when UTF-8 mode was not set.]
2184     5. A negated single-character class was not being recognized as fixed-length
2185        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2186        compile error "lookbehind assertion is not fixed length".
2188     6. The RunPerlTest auxiliary script was showing an unexpected difference
2189        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2190        write a Perl script that can interpret lines of an input file either as
2191        byte characters or as UTF-8, which is what "perltest" was being required to
2192        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2193        can't do is switch easily at run time between having the "use utf8;" pragma
2194        or not. In the end, I fudged it by using the RunPerlTest script to insert
2195        "use utf8;" explicitly for the UTF-8 tests.
2197     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2198        the end of the subject string, contrary to the documentation and to what
2199        Perl does. This was true of both matching functions. Now it matches only at
2200        the start of the subject and immediately after *internal* newlines.
2202     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2203        a pointer to an int instead of a pointer to an unsigned long int. This
2204        caused problems on 64-bit systems.
2206     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2207        instance of the 'standard' template library not being so standard".
2209    10. There was no check on the number of named subpatterns nor the maximum
2210        length of a subpattern name. The product of these values is used to compute
2211        the size of the memory block for a compiled pattern. By supplying a very
2212        long subpattern name and a large number of named subpatterns, the size
2213        computation could be caused to overflow. This is now prevented by limiting
2214        the length of names to 32 characters, and the number of named subpatterns
2215        to 10,000.
2217    11. Subpatterns that are repeated with specific counts have to be replicated in
2218        the compiled pattern. The size of memory for this was computed from the
2219        length of the subpattern and the repeat count. The latter is limited to
2220        65535, but there was no limit on the former, meaning that integer overflow
2221        could in principle occur. The compiled length of a repeated subpattern is
2222        now limited to 30,000 bytes in order to prevent this.
2224    12. Added the optional facility to have named substrings with the same name.
2226    13. Added the ability to use a named substring as a condition, using the
2227        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2228        are numbers (not recommended). Forward references are permitted.
2230    14. Added forward references in named backreferences (if you see what I mean).
2232    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2233        pattern could run off the end of the subject. For example, the pattern
2234        "(?s)(.{1,5})"8 did this with the subject "ab".
2236    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2237        PCRE_CASELESS was set when matching characters that were quantified with ?
2238        or *.
2240    17. A character class other than a single negated character that had a minimum
2241        but no maximum quantifier - for example [ab]{6,} - was not handled
2242        correctly by pce_dfa_exec(). It would match only one character.
2244    18. A valid (though odd) pattern that looked like a POSIX character
2245        class but used an invalid character after [ (for example [[,abc,]]) caused
2246        pcre_compile() to give the error "Failed: internal error: code overflow" or
2247        in some cases to crash with a glibc free() error. This could even happen if
2248        the pattern terminated after [[ but there just happened to be a sequence of
2249        letters, a binary zero, and a closing ] in the memory that followed.
2251    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2252        over the years. Originally (before any Unicode support), just the bottom 8
2253        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2254        output from "man perlunicode" includes this:
2256          The regular expression compiler produces polymorphic opcodes.  That
2257          is, the pattern adapts to the data and automatically switches to
2258          the Unicode character scheme when presented with Unicode data--or
2259          instead uses a traditional byte scheme when presented with byte
2260          data.
2262        Sadly, a wide octal escape does not cause a switch, and in a string with
2263        no other multibyte characters, these octal escapes are treated as before.
2264        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
2265        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2266        Unicode string.
2268        I have not perpetrated such confusion in PCRE. Up till now, it took just
2269        the bottom 8 bits, as in old Perl. I have now made octal escapes with
2270        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2271        translate to the appropriate multibyte character.
2273    29. Applied some refactoring to reduce the number of warnings from Microsoft
2274        and Borland compilers. This has included removing the fudge introduced
2275        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2276        a warning about an unused variable.
2278    21. PCRE has not included VT (character 0x0b) in the set of whitespace
2279        characters since release 4.0, because Perl (from release 5.004) does not.
2280        [Or at least, is documented not to: some releases seem to be in conflict
2281        with the documentation.] However, when a pattern was studied with
2282        pcre_study() and all its branches started with \s, PCRE still included VT
2283        as a possible starting character. Of course, this did no harm; it just
2284        caused an unnecessary match attempt.
2286    22. Removed a now-redundant internal flag bit that recorded the fact that case
2287        dependency changed within the pattern. This was once needed for "required
2288        byte" processing, but is no longer used. This recovers a now-scarce options
2289        bit. Also moved the least significant internal flag bit to the most-
2290        significant bit of the word, which was not previously used (hangover from
2291        the days when it was an int rather than a uint) to free up another bit for
2292        the future.
2294    23. Added support for CRLF line endings as well as CR and LF. As well as the
2295        default being selectable at build time, it can now be changed at runtime
2296        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2297        specify that it is scanning data with non-default line endings.
2299    24. Changed the definition of CXXLINK to make it agree with the definition of
2300        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2302    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2303        recursions. This makes a big different to stack usage for some patterns.
2305    26. If a subpattern containing a named recursion or subroutine reference such
2306        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2307        the space required for the compiled pattern went wrong and gave too small a
2308        value. Depending on the environment, this could lead to "Failed: internal
2309        error: code overflow at offset 49" or "glibc detected double free or
2310        corruption" errors.
2312    27. Applied patches from Google (a) to support the new newline modes and (b) to
2313        advance over multibyte UTF-8 characters in GlobalReplace.
2315    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2316        difference for some implementation of PCRE in some Windows version.
2318    29. Added some extra testing facilities to pcretest:
2320        \q<number>   in a data line sets the "match limit" value
2321        \Q<number>   in a data line sets the "match recursion limt" value
2322        -S <number>  sets the stack size, where <number> is in megabytes
2324        The -S option isn't available for Windows.
2327    Version 6.6 06-Feb-06
2328    ---------------------
2330     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2331        in pcreposix.h. I have copied the definition from pcre.h.
2333     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2334        because pcre.h is no longer a built file.
2336     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2337        not normally included in the compiled code.
2340    Version 6.5 01-Feb-06
2341    ---------------------
2343     1. When using the partial match feature with pcre_dfa_exec(), it was not
2344        anchoring the second and subsequent partial matches at the new starting
2345        point. This could lead to incorrect results. For example, with the pattern
2346        /1234/, partially matching against "123" and then "a4" gave a match.
2348     2. Changes to pcregrep:
2350        (a) All non-match returns from pcre_exec() were being treated as failures
2351            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2352            error message is output. Some extra information is given for the
2353            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2354            probably the only errors that are likely to be caused by users (by
2355            specifying a regex that has nested indefinite repeats, for instance).
2356            If there are more than 20 of these errors, pcregrep is abandoned.
2358        (b) A binary zero was treated as data while matching, but terminated the
2359            output line if it was written out. This has been fixed: binary zeroes
2360            are now no different to any other data bytes.
2362        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2363            used to set a locale for matching. The --locale=xxxx long option has
2364            been added (no short equivalent) to specify a locale explicitly on the
2365            pcregrep command, overriding the environment variables.
2367        (d) When -B was used with -n, some line numbers in the output were one less
2368            than they should have been.
2370        (e) Added the -o (--only-matching) option.
2372        (f) If -A or -C was used with -c (count only), some lines of context were
2373            accidentally printed for the final match.
2375        (g) Added the -H (--with-filename) option.
2377        (h) The combination of options -rh failed to suppress file names for files
2378            that were found from directory arguments.
2380        (i) Added the -D (--devices) and -d (--directories) options.
2382        (j) Added the -F (--fixed-strings) option.
2384        (k) Allow "-" to be used as a file name for -f as well as for a data file.
2386        (l) Added the --colo(u)r option.
2388        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2389            is not present by default.
2391     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2392        items such as (?R) or (?1), when the recursion could match a number of
2393        alternatives. If it matched one of the alternatives, but subsequently,
2394        outside the recursion, there was a failure, the code tried to back up into
2395        the recursion. However, because of the way PCRE is implemented, this is not
2396        possible, and the result was an incorrect result from the match.
2398        In order to prevent this happening, the specification of recursion has
2399        been changed so that all such subpatterns are automatically treated as
2400        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2402     4. I had overlooked the fact that, in some locales, there are characters for
2403        which isalpha() is true but neither isupper() nor islower() are true. In
2404        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2405        and ordfeminine) are like this. This affected the treatment of \w and \W
2406        when they appeared in character classes, but not when they appeared outside
2407        a character class. The bit map for "word" characters is now created
2408        separately from the results of isalnum() instead of just taking it from the
2409        upper, lower, and digit maps. (Plus the underscore character, of course.)
2411     5. The above bug also affected the handling of POSIX character classes such as
2412        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2413        permanent tables. Instead, the bit maps for such a class were previously
2414        created as the appropriate unions of the upper, lower, and digit bitmaps.
2415        Now they are created by subtraction from the [[:word:]] class, which has
2416        its own bitmap.
2418     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2419        It is created by subtracting the vertical space characters (\x09, \x0a,
2420        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2421        subtraction was done in the overall bitmap for a character class, meaning
2422        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2423        be recognized. This bug has been fixed.
2425     7. Patches from the folks at Google:
2427          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2428          real life, but is still worth protecting against".
2430          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2431          regular expressions".
2433          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2434          have it.
2436          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2437          "configure" and the latter not, in order to fix a problem somebody had
2438          with compiling the Arg class on HP-UX.
2440          (e) Improve the error-handling of the C++ wrapper a little bit.
2442          (f) New tests for checking recursion limiting.
2444     8. The pcre_memmove() function, which is used only if the environment does not
2445        have a standard memmove() function (and is therefore rarely compiled),
2446        contained two bugs: (a) use of int instead of size_t, and (b) it was not
2447        returning a result (though PCRE never actually uses the result).
2449     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2450        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2451        returned instead of calling malloc() with an overflowing number that would
2452        most likely cause subsequent chaos.
2454    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2456    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2457        with this option is matched, the nmatch and pmatch options of regexec() are
2458        ignored.
2460    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2461        provided in case anyone wants to the the POSIX interface with UTF-8
2462        strings.
2464    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2465        C++ linking (needed for some HP-UX environments).
2467    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2468        (unused parameter) and in the pcre_printint() function (omitted "default"
2469        switch label when the default is to do nothing).
2471    15. Added some code to make it possible, when PCRE is compiled as a C++
2472        library, to replace subject pointers for pcre_exec() with a smart pointer
2473        class, thus making it possible to process discontinuous strings.
2475    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2476        much the same function. They were added by different people who were trying
2477        to make PCRE easy to compile on non-Unix systems. It has been suggested
2478        that PCRE_EXPORT be abolished now that there is more automatic apparatus
2479        for compiling on Windows systems. I have therefore replaced it with
2480        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2481        defaults to "extern" for C or "extern C" for C++, which works fine on
2482        Unix-like systems. It is now possible to override the value of PCRE_DATA_
2483        SCOPE with something explicit in config.h. In addition:
2485        (a) pcreposix.h still had just "extern" instead of either of these macros;
2486            I have replaced it with PCRE_DATA_SCOPE.
2488        (b) Functions such as _pcre_xclass(), which are internal to the library,
2489            but external in the C sense, all had PCRE_EXPORT in their definitions.
2490            This is apparently wrong for the Windows case, so I have removed it.
2491            (It makes no difference on Unix-like systems.)
2493    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2494        of recursive calls to match(). This is different to MATCH_LIMIT because
2495        that limits the total number of calls to match(), not all of which increase
2496        the depth of recursion. Limiting the recursion depth limits the amount of
2497        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2498        when PCRE is compiled, and changed at run time. A patch from Google adds
2499        this functionality to the C++ interface.
2501    18. Changes to the handling of Unicode character properties:
2503        (a) Updated the table to Unicode 4.1.0.
2505        (b) Recognize characters that are not in the table as "Cn" (undefined).
2507        (c) I revised the way the table is implemented to a much improved format
2508            which includes recognition of ranges. It now supports the ranges that
2509            are defined in UnicodeData.txt, and it also amalgamates other
2510            characters into ranges. This has reduced the number of entries in the
2511            table from around 16,000 to around 3,000, thus reducing its size
2512            considerably. I realized I did not need to use a tree structure after
2513            all - a binary chop search is just as efficient. Having reduced the
2514            number of entries, I extended their size from 6 bytes to 8 bytes to
2515            allow for more data.
2517        (d) Added support for Unicode script names via properties such as \p{Han}.
2519    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2520        matching that character.
2522    20. When matching a repeated Unicode property with a minimum greater than zero,
2523        (for example \pL{2,}), PCRE could look past the end of the subject if it
2524        reached it while seeking the minimum number of characters. This could
2525        happen only if some of the characters were more than one byte long, because
2526        there is a check for at least the minimum number of bytes.
2528    21. Refactored the implementation of \p and \P so as to be more general, to
2529        allow for more different types of property in future. This has changed the
2530        compiled form incompatibly. Anybody with saved compiled patterns that use
2531        \p or \P will have to recompile them.
2533    22. Added "Any" and "L&" to the supported property types.
2535    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2536        but give a compile time error if the value is greater than 0xff.
2538    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2539        accidentally not being installed or uninstalled.
2541    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2542        made were to insert the current release number. This seemed silly, because
2543        it made things harder for people building PCRE on systems that don't run
2544        "configure". I have turned pcre.h into a distributed file, no longer built
2545        by "configure", with the version identification directly included. There is
2546        no longer a pcre.h.in file.
2548        However, this change necessitated a change to the pcre-config script as
2549        well. It is built from pcre-config.in, and one of the substitutions was the
2550        release number. I have updated configure.ac so that ./configure now finds
2551        the release number by grepping pcre.h.
2553    26. Added the ability to run the tests under valgrind.
2556    Version 6.4 05-Sep-05
2557    ---------------------
2559     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2560        "--" to be printed when multiple files were scanned, even when none of the
2561        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2562        consider it to be a bug, and have restored the previous behaviour.
2564     2. A couple of code tidies to get rid of compiler warnings.
2566     3. The pcretest program used to cheat by referring to symbols in the library
2567        whose names begin with _pcre_. These are internal symbols that are not
2568        really supposed to be visible externally, and in some environments it is
2569        possible to suppress them. The cheating is now confined to including
2570        certain files from the library's source, which is a bit cleaner.
2572     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2573        file's purpose clearer.
2575     5. Reorganized pcre_ucp_findchar().
2578    Version 6.3 15-Aug-05
2579    ---------------------
2581     1. The file libpcre.pc.in did not have general read permission in the tarball.
2583     2. There were some problems when building without C++ support:
2585        (a) If C++ support was not built, "make install" and "make test" still
2586            tried to test it.
2588        (b) There were problems when the value of CXX was explicitly set. Some
2589            changes have been made to try to fix these, and ...
2591        (c) --disable-cpp can now be used to explicitly disable C++ support.
2593        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2594            backslash in a target when C++ was disabled. This confuses some
2595            versions of "make", apparently. Using an intermediate variable solves
2596            this. (Same for CPP_LOBJ.)
2598     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2599        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2600        necessary on certain architectures.
2602     4. Added a setting of -export-symbols-regex to the link command to remove
2603        those symbols that are exported in the C sense, but actually are local
2604        within the library, and not documented. Their names all begin with
2605        "_pcre_". This is not a perfect job, because (a) we have to except some
2606        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2607        available (and never for static libraries). I have made a note to try to
2608        find a way round (a) in the future.
2611    Version 6.2 01-Aug-05
2612    ---------------------
2614     1. There was no test for integer overflow of quantifier values. A construction
2615        such as {1111111111111111} would give undefined results. What is worse, if
2616        a minimum quantifier for a parenthesized subpattern overflowed and became
2617        negative, the calculation of the memory size went wrong. This could have
2618        led to memory overwriting.
2620     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2622     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2623        operating environments where this matters.
2625     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2626        PCRE options from within the C++ wrapper.
2628     5. Named capturing subpatterns were not being correctly counted when a pattern
2629        was compiled. This caused two problems: (a) If there were more than 100
2630        such subpatterns, the calculation of the memory needed for the whole
2631        compiled pattern went wrong, leading to an overflow error. (b) Numerical
2632        back references of the form \12, where the number was greater than 9, were
2633        not recognized as back references, even though there were sufficient
2634        previous subpatterns.
2636     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2637        versions of gcc, e.g. 2.95.4.
2640    Version 6.1 21-Jun-05
2641    ---------------------
2643     1. There was one reference to the variable "posix" in pcretest.c that was not
2644        surrounded by "#if !defined NOPOSIX".
2646     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2647        the cross-check on the old pcre_info() function, for the benefit of the
2648        cut-down version of PCRE that is currently imported into Exim.
2650     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2651        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2652        patterns that start (?i) but I don't think that matters. The use of (?i) is
2653        just an example; this all applies to the other options as well.
2655     4. Since libtool seems to echo the compile commands it is issuing, the output
2656        from "make" can be reduced a bit by putting "@" in front of each libtool
2657        compile command.
2659     5. Patch from the folks at Google for configure.in to be a bit more thorough
2660        in checking for a suitable C++ installation before trying to compile the
2661        C++ stuff. This should fix a reported problem when a compiler was present,
2662        but no suitable headers.
2664     6. The man pages all had just "PCRE" as their title. I have changed them to
2665        be the relevant file name. I have also arranged that these names are
2666        retained in the file doc/pcre.txt, which is a concatenation in text format
2667        of all the man pages except the little individual ones for each function.
2669     7. The NON-UNIX-USE file had not been updated for the different set of source
2670        files that come with release 6. I also added a few comments about the C++
2671        wrapper.
2674    Version 6.0 07-Jun-05
2675    ---------------------
2677     1. Some minor internal re-organization to help with my DFA experiments.
2679     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2680        didn't matter for the library itself when fully configured, but did matter
2681        when compiling without UCP support, or within Exim, where the ucp files are
2682        not imported.
2684     3. Refactoring of the library code to split up the various functions into
2685        different source modules. The addition of the new DFA matching code (see
2686        below) to a single monolithic source would have made it really too
2687        unwieldy, quite apart from causing all the code to be include in a
2688        statically linked application, when only some functions are used. This is
2689        relevant even without the DFA addition now that patterns can be compiled in
2690        one application and matched in another.
2692        The downside of splitting up is that there have to be some external
2693        functions and data tables that are used internally in different modules of
2694        the library but which are not part of the API. These have all had their
2695        names changed to start with "_pcre_" so that they are unlikely to clash
2696        with other external names.
2698     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2699        a different (DFA) algorithm. Although it is slower than the original
2700        function, it does have some advantages for certain types of matching
2701        problem.
2703     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2704        including restarting after a partial match.
2706     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2707        defined when compiling for Windows was sent to me. I have put it into the
2708        code, though I have no means of testing or verifying it.
2710     7. Added the pcre_refcount() auxiliary function.
2712     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2713        match before or at the first newline in the subject string. In pcretest,
2714        the /f option on a pattern can be used to set this.
2716     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2717        would behave wrongly. This has been present in PCRE since release 4.0.
2719    10. A number of changes to the pcregrep command:
2721        (a) Refactored how -x works; insert ^(...)$ instead of setting
2722            PCRE_ANCHORED and checking the length, in preparation for adding
2723            something similar for -w.
2725        (b) Added the -w (match as a word) option.
2727        (c) Refactored the way lines are read and buffered so as to have more
2728            than one at a time available.
2730        (d) Implemented a pcregrep test script.
2732        (e) Added the -M (multiline match) option. This allows patterns to match
2733            over several lines of the subject. The buffering ensures that at least
2734            8K, or the rest of the document (whichever is the shorter) is available
2735            for matching (and similarly the previous 8K for lookbehind assertions).
2737        (f) Changed the --help output so that it now says
2739              -w, --word-regex(p)
2741            instead of two lines, one with "regex" and the other with "regexp"
2742            because that confused at least one person since the short forms are the
2743            same. (This required a bit of code, as the output is generated
2744            automatically from a table. It wasn't just a text change.)
2746        (g) -- can be used to terminate pcregrep options if the next thing isn't an
2747            option but starts with a hyphen. Could be a pattern or a path name
2748            starting with a hyphen, for instance.
2750        (h) "-" can be given as a file name to represent stdin.
2752        (i) When file names are being printed, "(standard input)" is used for
2753            the standard input, for compatibility with GNU grep. Previously
2754            "<stdin>" was used.
2756        (j) The option --label=xxx can be used to supply a name to be used for
2757            stdin when file names are being printed. There is no short form.
2759        (k) Re-factored the options decoding logic because we are going to add
2760            two more options that take data. Such options can now be given in four
2761            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2763        (l) Added the -A, -B, and -C options for requesting that lines of context
2764            around matches be printed.
2766        (m) Added the -L option to print the names of files that do not contain
2767            any matching lines, that is, the complement of -l.
2769        (n) The return code is 2 if any file cannot be opened, but pcregrep does
2770            continue to scan other files.
2772        (o) The -s option was incorrectly implemented. For compatibility with other
2773            greps, it now suppresses the error message for a non-existent or non-
2774            accessible file (but not the return code). There is a new option called
2775            -q that suppresses the output of matching lines, which was what -s was
2776            previously doing.
2778        (p) Added --include and --exclude options to specify files for inclusion
2779            and exclusion when recursing.
2781    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2782        Hopefully, it now does.
2784    12. Missing cast in pcre_study().
2786    13. Added an "uninstall" target to the makefile.
2788    14. Replaced "extern" in the function prototypes in Makefile.in with
2789        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2790        world, but is set differently for Windows.
2792    15. Added a second compiling function called pcre_compile2(). The only
2793        difference is that it has an extra argument, which is a pointer to an
2794        integer error code. When there is a compile-time failure, this is set
2795        non-zero, in addition to the error test pointer being set to point to an
2796        error message. The new argument may be NULL if no error number is required
2797        (but then you may as well call pcre_compile(), which is now just a
2798        wrapper). This facility is provided because some applications need a
2799        numeric error indication, but it has also enabled me to tidy up the way
2800        compile-time errors are handled in the POSIX wrapper.
2802    16. Added VPATH=.libs to the makefile; this should help when building with one
2803        prefix path and installing with another. (Or so I'm told by someone who
2804        knows more about this stuff than I do.)
2806    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2807        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2808        match everything, including newlines. This is not POSIX-compatible, but
2809        somebody wanted the feature. From pcretest it can be activated by using
2810        both the P and the s flags.
2812    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2814    19. libpcre.pc was being incorrectly installed as executable.
2816    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2817        it now also looks for '\r' so that it will work unmodified on Windows.
2819    21. Added Google's contributed C++ wrapper to the distribution.
2821    22. Added some untidy missing memory free() calls in pcretest, to keep
2822        Electric Fence happy when testing.
2826    Version 5.0 13-Sep-04
2827    ---------------------
2829     1. Internal change: literal characters are no longer packed up into items
2830        containing multiple characters in a single byte-string. Each character
2831        is now matched using a separate opcode. However, there may be more than one
2832        byte in the character in UTF-8 mode.
2834     2. The pcre_callout_block structure has two new fields: pattern_position and
2835        next_item_length. These contain the offset in the pattern to the next match
2836        item, and its length, respectively.
2838     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2839        insertion of callouts before each pattern item. Added the /C option to
2840        pcretest to make use of this.
2842     4. On the advice of a Windows user, the lines
2844          #if defined(_WIN32) || defined(WIN32)
2845          _setmode( _fileno( stdout ), 0x8000 );
2846          #endif  /* defined(_WIN32) || defined(WIN32) */
2848        have been added to the source of pcretest. This apparently does useful
2849        magic in relation to line terminators.
2851     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2852        for the benefit of those environments where the "b" makes a difference.
2854     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2855        to know about it. I have put a hack into configure.in that adds in code
2856        to set GCC=yes if CC=icc. This seems to end up at a point in the
2857        generated configure script that is early enough to affect the setting of
2858        compiler options, which is what is needed, but I have no means of testing
2859        whether it really works. (The user who reported this had patched the
2860        generated configure script, which of course I cannot do.)
2862        LATER: After change 22 below (new libtool files), the configure script
2863        seems to know about icc (and also ecc). Therefore, I have commented out
2864        this hack in configure.in.
2866     7. Added support for pkg-config (2 patches were sent in).
2868     8. Negated POSIX character classes that used a combination of internal tables
2869        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2870        [[:^ascii]]. Typically, they would match almost any characters. The other
2871        POSIX classes were not broken in this way.
2873     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2874        to find the match, as PCRE was deluded into thinking that the match had to
2875        start at the start point or following a newline. The same bug applied to
2876        patterns with negative forward assertions or any backward assertions
2877        preceding ".*" at the start, unless the pattern required a fixed first
2878        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2880    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2881        starting at the last subject character, bytes beyond the end of the subject
2882        string were read.
2884    11. Renamed the variable "class" as "classbits" to make life easier for C++
2885        users. (Previously there was a macro definition, but it apparently wasn't
2886        enough.)
2888    12. Added the new field "tables" to the extra data so that tables can be passed
2889        in at exec time, or the internal tables can be re-selected. This allows
2890        a compiled regex to be saved and re-used at a later time by a different
2891        program that might have everything at different addresses.
2893    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2894        -R library as well as a -L library.
2896    14. The debugging options of pcretest (-d on the command line or D on a
2897        pattern) showed incorrect output for anything following an extended class
2898        that contained multibyte characters and which was followed by a quantifier.
2900    15. Added optional support for general category Unicode character properties
2901        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2902        support. It adds about 90K to the size of the library. The meanings of the
2903        inbuilt class escapes such as \d and \s have NOT been changed.
2905    16. Updated pcredemo.c to include calls to free() to release the memory for the
2906        compiled pattern.
2908    17. The generated file chartables.c was being created in the source directory
2909        instead of in the building directory. This caused the build to fail if the
2910        source directory was different from the building directory, and was
2911        read-only.
2913    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2914        file. No doubt somebody will tell me if they don't make sense... Also added
2915        Dan Mooney's comments about building on OpenVMS.
2917    19. Added support for partial matching via the PCRE_PARTIAL option for
2918        pcre_exec() and the \P data escape in pcretest.
2920    20. Extended pcretest with 3 new pattern features:
2922        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2923              write the compiled pattern to the file whose name is "rest-of-line".
2924              This is a straight binary dump of the data, with the saved pointer to
2925              the character tables forced to be NULL. The study data, if any, is
2926              written too. After writing, pcretest reads a new pattern.
2928        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2929              compiled pattern from the given file. There must not be any
2930              occurrences of "<" in the file name (pretty unlikely); if there are,
2931              pcretest will instead treat the initial "<" as a pattern delimiter.
2932              After reading in the pattern, pcretest goes on to read data lines as
2933              usual.
2935        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2936              and 16-bit fields in a compiled pattern, to simulate a pattern that
2937              was compiled on a host of opposite endianness.
2939    21. The pcre-exec() function can now cope with patterns that were compiled on
2940        hosts of opposite endianness, with this restriction:
2942          As for any compiled expression that is saved and used later, the tables
2943          pointer field cannot be preserved; the extra_data field in the arguments
2944          to pcre_exec() should be used to pass in a tables address if a value
2945          other than the default internal tables were used at compile time.
2947    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2948        now diagnosed as an error. Previously, most of the time, a negative number
2949        would have been treated as zero, but if in addition "ovector" was passed as
2950        NULL, a crash could occur.
2952    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2953        new versions from the libtool 1.5 distribution (the last one is a copy of
2954        a file called libtool.m4). This seems to have fixed the need to patch
2955        "configure" to support Darwin 1.3 (which I used to do). However, I still
2956        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2957        workstation).
2959    24. Changed the PCRE licence to be the more standard "BSD" licence.
2962  Version 4.5 01-Dec-03  Version 4.5 01-Dec-03
2963  ---------------------  ---------------------

Removed from v.73  
changed lines
  Added in v.701

  ViewVC Help
Powered by ViewVC 1.1.5