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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.4 10-Sep-07  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 captured
14       substring, but while checking the failing first alternative, substring 1 is
15       temporarily captured. If the output vector supplied to pcre_exec() was not
16       big enough for this capture, the yield of the function was still zero
17       ("insufficient space for captured substrings"). This cannot be totally fixed
18       without adding another stack variable, which seems a lot of expense for a
19       edge case. However, I have improved the situation in cases such as
20       /(a)(b)x|abc/ matched against "abc", where the return code indicates that
21       fewer than the maximum number of slots in the ovector have been set.
23    3. Related to (2) above: when there are more back references in a pattern than
24       slots in the output vector, pcre_exec() uses temporary memory during
25       matching, and copies in the captures as far as possible afterwards. It was
26       using the entire output vector, but this conflicts with the specification
27       that only 2/3 is used for passing back captured substrings. Now it uses only
28       the first 2/3, for compatibility. This is, of course, another edge case.
30    4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
31       main code base, and can be used by building with --enable-jit. When this is
32       done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
33       runtime --no-jit option is given.
35    5. When the number of matches in a pcre_dfa_exec() run exactly filled the
36       ovector, the return from the function was zero, implying that there were
37       other matches that did not fit. The correct "exactly full" value is now
38       returned.
40    6. If a subpattern that was called recursively or as a subroutine contained
41       (*PRUNE) or any other control that caused it to give a non-standard return,
42       invalid errors such as "Error -26 (nested recursion at the same subject
43       position)" or even infinite loops could occur.
45    7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
46       computing the minimum length on reaching *ACCEPT, and so ended up with the
47       wrong value of 1 rather than 0. Further investigation indicates that
48       computing a minimum subject length in the presence of *ACCEPT is difficult
49       (think back references, subroutine calls), and so I have changed the code so
50       that no minimum is registered for a pattern that contains *ACCEPT.
53    Version 8.13 16-Aug-2011
54    ------------------------
56    1.  The Unicode data tables have been updated to Unicode 6.0.0.
58    2.  Two minor typos in pcre_internal.h have been fixed.
60    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
61        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
62        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
64    4.  There were a number of related bugs in the code for matching backrefences
65        caselessly in UTF-8 mode when codes for the characters concerned were
66        different numbers of bytes. For example, U+023A and U+2C65 are an upper
67        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
68        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
69        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
70        2-byte code at the end of the subject (it thought there wasn't enough data
71        left).
73    5.  Comprehensive information about what went wrong is now returned by
74        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
75        as the output vector has at least 2 elements. The offset of the start of
76        the failing character and a reason code are placed in the vector.
78    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
79        now returned is for the first byte of the failing character, instead of the
80        last byte inspected. This is an incompatible change, but I hope it is small
81        enough not to be a problem. It makes the returned offset consistent with
82        pcre_exec() and pcre_dfa_exec().
84    7.  pcretest now gives a text phrase as well as the error number when
85        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
86        failure, the offset and reason code are output.
88    8.  When \R was used with a maximizing quantifier it failed to skip backwards
89        over a \r\n pair if the subsequent match failed. Instead, it just skipped
90        back over a single character (\n). This seems wrong (because it treated the
91        two characters as a single entity when going forwards), conflicts with the
92        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
93        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
94        has been changed.
96    9.  Some internal refactoring has changed the processing so that the handling
97        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
98        time (the PCRE_DOTALL option was changed this way some time ago: version
99        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
100        which was always a bit of a fudge. It also means that there is one less
101        argument for the match() function, which reduces its stack requirements
102        slightly. This change also fixes an incompatibility with Perl: the pattern
103        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
105    10. More internal refactoring has drastically reduced the number of recursive
106        calls to match() for possessively repeated groups such as (abc)++ when
107        using pcre_exec().
109    11. While implementing 10, a number of bugs in the handling of groups were
110        discovered and fixed:
112        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
113        (a|)*(?1) gave a compile-time internal error.
114        ((a|)+)+  did not notice that the outer group could match an empty string.
115        (^a|^)+   was not marked as anchored.
116        (.*a|.*)+ was not marked as matching at start or after a newline.
118    12. Yet more internal refactoring has removed another argument from the match()
119        function. Special calls to this function are now indicated by setting a
120        value in a variable in the "match data" data block.
122    13. Be more explicit in pcre_study() instead of relying on "default" for
123        opcodes that mean there is no starting character; this means that when new
124        ones are added and accidentally left out of pcre_study(), testing should
125        pick them up.
127    14. The -s option of pcretest has been documented for ages as being an old
128        synonym of -m (show memory usage). I have changed it to mean "force study
129        for every regex", that is, assume /S for every regex. This is similar to -i
130        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
131        using it. It makes it easier to run collections of tests with and without
132        study enabled, and thereby test pcre_study() more easily. All the standard
133        tests are now run with and without -s (but some patterns can be marked as
134        "never study" - see 20 below).
136    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
137        restoration of the capturing data to the outer values was not happening
138        correctly.
140    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
141        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
142        pattern had matched an empty string, and so incorrectly returned a no
143        match.
145    17. There was optimizing code for the last branch of non-capturing parentheses,
146        and also for the obeyed branch of a conditional subexpression, which used
147        tail recursion to cut down on stack usage. Unfortunately, now that there is
148        the possibility of (*THEN) occurring in these branches, tail recursion is
149        no longer possible because the return has to be checked for (*THEN). These
150        two optimizations have therefore been removed.
152    18. If a pattern containing \R was studied, it was assumed that \R always
153        matched two bytes, thus causing the minimum subject length to be
154        incorrectly computed because \R can also match just one byte.
156    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
157        was incorrectly computed.
159    20. If /S is present twice on a test pattern in pcretest input, it now
160        *disables* studying, thereby overriding the use of -s on the command line
161        (see 14 above). This is necessary for one or two tests to keep the output
162        identical in both cases.
164    21. When (*ACCEPT) was used in an assertion that matched an empty string and
165        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
167    22. When an atomic group that contained a capturing parenthesis was
168        successfully matched, but the branch in which it appeared failed, the
169        capturing was not being forgotten if a higher numbered group was later
170        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
171        group 1 to "a", when in fact it should be unset. This applied to multi-
172        branched capturing and non-capturing groups, repeated or not, and also to
173        positive assertions (capturing in negative assertions does not happen
174        in PCRE) and also to nested atomic groups.
176    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
177        subject after a captured substring, to make it easier to tell which of a
178        number of identical substrings has been captured.
180    24. The way atomic groups are processed by pcre_exec() has been changed so that
181        if they are repeated, backtracking one repetition now resets captured
182        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
183        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
184        "aaa". Previously, it would have been "a". As part of this code
185        refactoring, the way recursive calls are handled has also been changed.
187    25. If an assertion condition captured any substrings, they were not passed
188        back unless some other capturing happened later. For example, if
189        (?(?=(a))a) was matched against "a", no capturing was returned.
191    26. When studying a pattern that contained subroutine calls or assertions,
192        the code for finding the minimum length of a possible match was handling
193        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
194        group 1 called group 2 while simultaneously a separate group 2 called group
195        1). A stack overflow occurred in this case. I have fixed this by limiting
196        the recursion depth to 10.
198    27. Updated RunTest.bat in the distribution to the version supplied by Tom
199        Fortmann. This supports explicit test numbers on the command line, and has
200        argument validation and error reporting.
202    28. An instance of \X with an unlimited repeat could fail if at any point the
203        first character it looked at was a mark character.
205    29. Some minor code refactoring concerning Unicode properties and scripts
206        should reduce the stack requirement of match() slightly.
208    30. Added the '=' option to pcretest to check the setting of unused capturing
209        slots at the end of the pattern, which are documented as being -1, but are
210        not included in the return count.
212    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
213        compiled something random. Now it gives a compile-time error (as does
214        Perl).
216    32. A *MARK encountered during the processing of a positive assertion is now
217        recorded and passed back (compatible with Perl).
219    33. If --only-matching or --colour was set on a pcregrep call whose pattern
220        had alternative anchored branches, the search for a second match in a line
221        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
222        matched the line "0102" twice. The same bug affected patterns that started
223        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
224        twice.
226    34. Previously, PCRE did not allow quantification of assertions. However, Perl
227        does, and because of capturing effects, quantifying parenthesized
228        assertions may at times be useful. Quantifiers are now allowed for
229        parenthesized assertions.
231    35. A minor code tidy in pcre_compile() when checking options for \R usage.
233    36. \g was being checked for fancy things in a character class, when it should
234        just be a literal "g".
236    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
237        appearance of a nested POSIX class supersedes an apparent external class.
238        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
239        unescaped square brackets may also appear as part of class names. For
240        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
241        more like Perl. (But see 8.20/1 above.)
243    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
244        was because it thought it was \N{name}, which is not supported).
246    39. Add minix to OS list not supporting the -S option in pcretest.
248    40. PCRE tries to detect cases of infinite recursion at compile time, but it
249        cannot analyze patterns in sufficient detail to catch mutual recursions
250        such as ((?1))((?2)). There is now a runtime test that gives an error if a
251        subgroup is called recursively as a subpattern for a second time at the
252        same position in the subject string. In previous releases this might have
253        been caught by the recursion limit, or it might have run out of stack.
255    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
256        happen only once. PCRE was, however incorrectly giving a compile time error
257        "recursive call could loop indefinitely" because it cannot analyze the
258        pattern in sufficient detail. The compile time test no longer happens when
259        PCRE is compiling a conditional subpattern, but actual runaway loops are
260        now caught at runtime (see 40 above).
262    42. It seems that Perl allows any characters other than a closing parenthesis
263        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
264        has been changed to be the same.
266    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
267        as not to get warnings when autogen.sh is called. Also changed
268        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
270    44. To help people who use pcregrep to scan files containing exceedingly long
271        lines, the following changes have been made:
273        (a) The default value of the buffer size parameter has been increased from
274            8K to 20K. (The actual buffer used is three times this size.)
276        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
277            PCRE is built.
279        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
280            to be set at run time.
282        (d) Numerical values in pcregrep options can be followed by K or M, for
283            example --buffer-size=50K.
285        (e) If a line being scanned overflows pcregrep's buffer, an error is now
286            given and the return code is set to 2.
288    45. Add a pointer to the latest mark to the callout data block.
290    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
291        partial match of an empty string instead of no match. This was specific to
292        the use of ".".
294    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
295        complete match instead of a partial match. This bug was dependent on both
296        the PCRE_UTF8 and PCRE_DOTALL options being set.
298    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
299        starting byte set, because \b was not being ignored.
302    Version 8.12 15-Jan-2011
303    ------------------------
305    1.  Fixed some typos in the markup of the man pages, and wrote a script that
306        checks for such things as part of the documentation building process.
308    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
309        --match-limit and --recursion-limit options (added for 8.11). In
310        particular, this made one of the standard tests fail. (The integer value
311        went into the wrong half of a long int.)
313    3.  If the --colour option was given to pcregrep with -v (invert match), it
314        did strange things, either producing crazy output, or crashing. It should,
315        of course, ignore a request for colour when reporting lines that do not
316        match.
318    4.  Another pcregrep bug caused similar problems if --colour was specified with
319        -M (multiline) and the pattern match finished with a line ending.
321    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
322        matched in multiline mode, the following line was shown as part of the
323        match. This seems wrong, so I have changed it.
325    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
326        the check for further matches in the same line (so they could be coloured)
327        to overrun the end of the current line. If another match was found, it was
328        incorrectly shown (and then shown again when found in the next line).
330    7.  If pcregrep was compiled under Windows, there was a reference to the
331        function pcregrep_exit() before it was defined. I am assuming this was
332        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
333        reported by a user. I've moved the definition above the reference.
336    Version 8.11 10-Dec-2010
337    ------------------------
339    1.  (*THEN) was not working properly if there were untried alternatives prior
340        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
341        backtracked to try for "b" instead of moving to the next alternative branch
342        at the same level (in this case, to look for "c"). The Perl documentation
343        is clear that when (*THEN) is backtracked onto, it goes to the "next
344        alternative in the innermost enclosing group".
346    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
347        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
348        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
349        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
350        (*THEN).
352    3.  If \s appeared in a character class, it removed the VT character from
353        the class, even if it had been included by some previous item, for example
354        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
355        of \s, but is part of the POSIX "space" class.)
357    4.  A partial match never returns an empty string (because you can always
358        match an empty string at the end of the subject); however the checking for
359        an empty string was starting at the "start of match" point. This has been
360        changed to the "earliest inspected character" point, because the returned
361        data for a partial match starts at this character. This means that, for
362        example, /(?<=abc)def/ gives a partial match for the subject "abc"
363        (previously it gave "no match").
365    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
366        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
367        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
368        has an implication that the given string is incomplete (because a partial
369        match is preferred over a full match). For this reason, these items now
370        give a partial match in this situation. [Aside: previously, the one case
371        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
372        match rather than a full match, which was wrong by the old rules, but is
373        now correct.]
375    6.  There was a bug in the handling of #-introduced comments, recognized when
376        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
377        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
378        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
379        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
380        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
381        places in pcre_compile().
383    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
384        comments when looking ahead for named forward references to subpatterns,
385        the only newline sequence it recognized was NL. It now handles newlines
386        according to the set newline convention.
388    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
389        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
390        cater for a lack of strerror(). These oversights have been fixed.
392    9.  Added --match-limit and --recursion-limit to pcregrep.
394    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
396    11. When the -o option was used, pcregrep was setting a return code of 1, even
397        when matches were found, and --line-buffered was not being honoured.
399    12. Added an optional parentheses number to the -o and --only-matching options
400        of pcregrep.
402    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
403        can match an empty string. The code to do it in pcretest and pcredemo
404        needed fixing:
406        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
407            only one byte after an empty string match just before CRLF (this case
408            just got forgotten; "any" and "anycrlf" were OK).
410        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
411            mode when an empty string match preceded an ASCII character followed by
412            a non-ASCII character. (The code for advancing by one character rather
413            than one byte was nonsense.)
415        (c) The pcredemo.c sample program did not have any code at all to handle
416            the cases when CRLF is a valid newline sequence.
418    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
419        as a starting offset was within the subject string. There is now a new
420        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
421        negative or greater than the length of the string. In order to test this,
422        pcretest is extended to allow the setting of negative starting offsets.
424    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
425        starting offset points to the beginning of a UTF-8 character was
426        unnecessarily clumsy. I tidied it up.
428    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
429        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
431    17. Nobody had reported that the --include_dir option, which was added in
432        release 7.7 should have been called --include-dir (hyphen, not underscore)
433        for compatibility with GNU grep. I have changed it to --include-dir, but
434        left --include_dir as an undocumented synonym, and the same for
435        --exclude-dir, though that is not available in GNU grep, at least as of
436        release 2.5.4.
438    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
439        characters from a string of bytes) have been redefined so as not to use
440        loops, in order to improve performance in some environments. At the same
441        time, I abstracted some of the common code into auxiliary macros to save
442        repetition (this should not affect the compiled code).
444    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
445        compile-time error is now given if \c is not followed by an ASCII
446        character, that is, a byte less than 128. (In EBCDIC mode, the code is
447        different, and any byte value is allowed.)
449    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
450        START_OPTIMIZE option, which is now allowed at compile time - but just
451        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
452        to pcregrep and other applications that have no direct access to PCRE
453        options. The new /Y option in pcretest sets this option when calling
454        pcre_compile().
456    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
457        back references. Groups containing recursive back references were forced to
458        be atomic by that change, but in the case of named groups, the amount of
459        memory required was incorrectly computed, leading to "Failed: internal
460        error: code overflow". This has been fixed.
462    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
463        pcretest.c, to avoid build problems in some Borland environments.
466    Version 8.10 25-Jun-2010
467    ------------------------
469    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
470        THEN.
472    2.  (*ACCEPT) was not working when inside an atomic group.
474    3.  Inside a character class, \B is treated as a literal by default, but
475        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
476        causes the error). The code is unchanged, but I tidied the documentation.
478    4.  Inside a character class, PCRE always treated \R and \X as literals,
479        whereas Perl faults them if its -w option is set. I have changed PCRE so
480        that it faults them when PCRE_EXTRA is set.
482    5.  Added support for \N, which always matches any character other than
483        newline. (It is the same as "." when PCRE_DOTALL is not set.)
485    6.  When compiling pcregrep with newer versions of gcc which may have
486        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
487        declared with attribute warn_unused_result" were given. Just casting the
488        result to (void) does not stop the warnings; a more elaborate fudge is
489        needed. I've used a macro to implement this.
491    7.  Minor change to pcretest.c to avoid a compiler warning.
493    8.  Added four artifical Unicode properties to help with an option to make
494        \s etc use properties (see next item). The new properties are: Xan
495        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
497    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
498        use Unicode properties. (*UCP) at the start of a pattern can be used to set
499        this option. Modified pcretest to add /W to test this facility. Added
500        REG_UCP to make it available via the POSIX interface.
502    10. Added --line-buffered to pcregrep.
504    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
505        studied, and the match started with a letter with a code point greater than
506        127 whose first byte was different to the first byte of the other case of
507        the letter, the other case of this starting letter was not recognized
508        (#976).
510    12. If a pattern that was studied started with a repeated Unicode property
511        test, for example, \p{Nd}+, there was the theoretical possibility of
512        setting up an incorrect bitmap of starting bytes, but fortunately it could
513        not have actually happened in practice until change 8 above was made (it
514        added property types that matched character-matching opcodes).
516    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
517        possible starting bytes for non-anchored patterns.
519    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
520        \R, and also a number of cases that involve Unicode properties, both
521        explicit and implicit when PCRE_UCP is set.
523    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
524        input, it could crash or give wrong results if characters with values
525        greater than 0xc0 were present in the subject string. (Detail: it assumed
526        UTF-8 input when processing these items.)
528    16. Added a lot of (int) casts to avoid compiler warnings in systems where
529        size_t is 64-bit (#991).
531    17. Added a check for running out of memory when PCRE is compiled with
532        --disable-stack-for-recursion (#990).
534    18. If the last data line in a file for pcretest does not have a newline on
535        the end, a newline was missing in the output.
537    19. The default pcre_chartables.c file recognizes only ASCII characters (values
538        less than 128) in its various bitmaps. However, there is a facility for
539        generating tables according to the current locale when PCRE is compiled. It
540        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
541        characters, are recognized by isspace() and therefore were getting set in
542        these tables, and indeed these tables seem to approximate to ISO 8859. This
543        caused a problem in UTF-8 mode when pcre_study() was used to create a list
544        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
545        which of course cannot start UTF-8 characters. I have changed the code so
546        that only real ASCII characters (less than 128) and the correct starting
547        bytes for UTF-8 encodings are set for characters greater than 127 when in
548        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
549        altogether.)
551    20. Added the /T option to pcretest so as to be able to run tests with non-
552        standard character tables, thus making it possible to include the tests
553        used for 19 above in the standard set of tests.
555    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
556        reference to a subpattern the other side of a comment that contains an
557        opening parenthesis caused either an internal compiling error, or a
558        reference to the wrong subpattern.
561    Version 8.02 19-Mar-2010
562    ------------------------
564    1.  The Unicode data tables have been updated to Unicode 5.2.0.
566    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
567        configured.
569    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
570        original author of that file, following a query about its status.
572    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
573        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
575    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
576        quantifier applied to a forward-referencing subroutine call, could compile
577        incorrect code or give the error "internal error: previously-checked
578        referenced subpattern not found".
580    6.  Both MS Visual Studio and Symbian OS have problems with initializing
581        variables to point to external functions. For these systems, therefore,
582        pcre_malloc etc. are now initialized to local functions that call the
583        relevant global functions.
585    7.  There were two entries missing in the vectors called coptable and poptable
586        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
587        I've fixed the data, and added a kludgy way of testing at compile time that
588        the lengths are correct (equal to the number of opcodes).
590    8.  Following on from 7, I added a similar kludge to check the length of the
591        eint vector in pcreposix.c.
593    9.  Error texts for pcre_compile() are held as one long string to avoid too
594        much relocation at load time. To find a text, the string is searched,
595        counting zeros. There was no check for running off the end of the string,
596        which could happen if a new error number was added without updating the
597        string.
599    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
601    11. \K was not working if it appeared in an atomic group or in a group that
602        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
603        \K is "not well defined" if used in an assertion. PCRE now accepts it if
604        the assertion is positive, but not if it is negative.
606    12. Change 11 fortuitously reduced the size of the stack frame used in the
607        "match()" function of pcre_exec.c by one pointer. Forthcoming
608        implementation of support for (*MARK) will need an extra pointer on the
609        stack; I have reserved it now, so that the stack frame size does not
610        decrease.
612    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
613        item in branch that calls a recursion is a subroutine call - as in the
614        second branch in the above example - was incorrectly given the compile-
615        time error "recursive call could loop indefinitely" because pcre_compile()
616        was not correctly checking the subroutine for matching a non-empty string.
618    14. The checks for overrunning compiling workspace could trigger after an
619        overrun had occurred. This is a "should never occur" error, but it can be
620        triggered by pathological patterns such as hundreds of nested parentheses.
621        The checks now trigger 100 bytes before the end of the workspace.
623    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
626    Version 8.01 19-Jan-2010
627    ------------------------
629    1.  If a pattern contained a conditional subpattern with only one branch (in
630        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
631        computed the wrong minimum data length (which is of course zero for such
632        subpatterns). This could cause incorrect "no match" results.
634    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
635        the pattern is reset in the first branch, pcre_compile() failed with
636        "internal error: code overflow at offset...". This happened only when
637        the reset was to the original external option setting. (An optimization
638        abstracts leading options settings into an external setting, which was the
639        cause of this.)
641    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
642        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
643        assertion pattern did not match (meaning that the assertion was true), it
644        was incorrectly treated as false if the SKIP had been reached during the
645        matching. This also applied to assertions used as conditions.
647    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
648        assertion subpattern, including such a pattern used as a condition,
649        unpredictable results occurred, instead of the error return
652    5.  The C++ GlobalReplace function was not working like Perl for the special
653        situation when an empty string is matched. It now does the fancy magic
654        stuff that is necessary.
656    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
657        removed. (These were left over from very, very early versions of PCRE.)
659    7.  Some cosmetic changes to the code to make life easier when compiling it
660        as part of something else:
662        (a) Change DEBUG to PCRE_DEBUG.
664        (b) In pcre_compile(), rename the member of the "branch_chain" structure
665            called "current" as "current_branch", to prevent a collision with the
666            Linux macro when compiled as a kernel module.
668        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
669            prevent a collision with the Linux macro when compiled as a kernel
670            module.
672    8.  In pcre_compile() there are some checks for integer overflows that used to
673        cast potentially large values to (double). This has been changed to that
674        when building, a check for int64_t is made, and if it is found, it is used
675        instead, thus avoiding the use of floating point arithmetic. (There is no
676        other use of FP in PCRE.) If int64_t is not found, the fallback is to
677        double.
679    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
680        2005 (difference between two addresses compared to an unsigned value).
682    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
683        custom one, because of the following reported problem in Windows:
685          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
686              under Win32.
687          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
688              therefore missing the function definition.
689          - The compiler thus generates a "C" signature for the test function.
690          - The linker fails to find the "C" function.
691          - PCRE fails to configure if asked to do so against libbz2.
693    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
694        messages were output:
696          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
697          rerunning libtoolize, to keep the correct libtool macros in-tree.
698          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
700        I have done both of these things.
702    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
703        most of the time, it *can* run out if it is given a pattern that contains a
704        runaway infinite recursion. I updated the discussion in the pcrestack man
705        page.
707    13. Now that we have gone to the x.xx style of version numbers, the minor
708        version may start with zero. Using 08 or 09 is a bad idea because users
709        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
710        interpreted as invalid octal numbers. I've updated the previous comment in
711        configure.ac, and also added a check that gives an error if 08 or 09 are
712        used.
714    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
715        causing partial matching to fail when the end of the subject matched \W
716        in a UTF-8 pattern where \W was quantified with a minimum of 3.
718    15. There were some discrepancies between the declarations in pcre_internal.h
719        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
720        their definitions. The declarations used "const uschar *" and the
721        definitions used USPTR. Even though USPTR is normally defined as "const
722        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
723        reported that: "This difference in casting confuses some C++ compilers, for
724        example, SunCC recognizes above declarations as different functions and
725        generates broken code for hbpcre." I have changed the declarations to use
726        USPTR.
728    16. GNU libtool is named differently on some systems. The autogen.sh script now
729        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
730        (FreeBSD).
732    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
733        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
734        comment: "Figure out how to create a longlong from a string: strtoll and
735        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
736        instance, but it only takes 2 args instead of 3!"
738    18. A subtle bug concerned with back references has been fixed by a change of
739        specification, with a corresponding code fix. A pattern such as
740        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
741        refers, was giving matches when it shouldn't. For example, xa=xaaa would
742        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
743        same bug. Such groups have to be quantified to be useful, or contained
744        inside another quantified group. (If there's no repetition, the reference
745        can never match.) The problem arises because, having left the group and
746        moved on to the rest of the pattern, a later failure that backtracks into
747        the group uses the captured value from the final iteration of the group
748        rather than the correct earlier one. I have fixed this in PCRE by forcing
749        any group that contains a reference to itself to be an atomic group; that
750        is, there cannot be any backtracking into it once it has completed. This is
751        similar to recursive and subroutine calls.
754    Version 8.00 19-Oct-09
755    ----------------------
757    1.  The table for translating pcre_compile() error codes into POSIX error codes
758        was out-of-date, and there was no check on the pcre_compile() error code
759        being within the table. This could lead to an OK return being given in
760        error.
762    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
763        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
764        in a Windows environment.
766    3.  The pcregrep --count option prints the count for each file even when it is
767        zero, as does GNU grep. However, pcregrep was also printing all files when
768        --files-with-matches was added. Now, when both options are given, it prints
769        counts only for those files that have at least one match. (GNU grep just
770        prints the file name in this circumstance, but including the count seems
771        more useful - otherwise, why use --count?) Also ensured that the
772        combination -clh just lists non-zero counts, with no names.
774    4.  The long form of the pcregrep -F option was incorrectly implemented as
775        --fixed_strings instead of --fixed-strings. This is an incompatible change,
776        but it seems right to fix it, and I didn't think it was worth preserving
777        the old behaviour.
779    5.  The command line items --regex=pattern and --regexp=pattern were not
780        recognized by pcregrep, which required --regex pattern or --regexp pattern
781        (with a space rather than an '='). The man page documented the '=' forms,
782        which are compatible with GNU grep; these now work.
784    6.  No libpcreposix.pc file was created for pkg-config; there was just
785        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
787    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
788        when UCP support is not needed, by modifying the Python script that
789        generates it from Unicode data files. This should not matter if the module
790        is correctly used as a library, but I received one complaint about 50K of
791        unwanted data. My guess is that the person linked everything into his
792        program rather than using a library. Anyway, it does no harm.
794    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
795        was a minimum greater than 1 for a wide character in a possessive
796        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
797        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
798        character. Chaos in the form of incorrect output or a compiling loop could
799        result.
801    9.  The restrictions on what a pattern can contain when partial matching is
802        requested for pcre_exec() have been removed. All patterns can now be
803        partially matched by this function. In addition, if there are at least two
804        slots in the offset vector, the offset of the earliest inspected character
805        for the match and the offset of the end of the subject are set in them when
806        PCRE_ERROR_PARTIAL is returned.
808    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
809        synonymous with PCRE_PARTIAL, for backwards compatibility, and
810        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
811        and may be more useful for multi-segment matching.
813    11. Partial matching with pcre_exec() is now more intuitive. A partial match
814        used to be given if ever the end of the subject was reached; now it is
815        given only if matching could not proceed because another character was
816        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
817        string "Z", which now yields "no match" instead of "partial match". In the
818        case of pcre_dfa_exec(), "no match" is given if every matching path for the
819        final character ended with (*FAIL).
821    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
822        if the pattern had a "must contain" character that was already found in the
823        earlier partial match, unless partial matching was again requested. For
824        example, with the pattern /dog.(body)?/, the "must contain" character is
825        "g". If the first part-match was for the string "dog", restarting with
826        "sbody" failed. This bug has been fixed.
828    13. The string returned by pcre_dfa_exec() after a partial match has been
829        changed so that it starts at the first inspected character rather than the
830        first character of the match. This makes a difference only if the pattern
831        starts with a lookbehind assertion or \b or \B (\K is not supported by
832        pcre_dfa_exec()). It's an incompatible change, but it makes the two
833        matching functions compatible, and I think it's the right thing to do.
835    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
836        so that the demonstration program is easily available in environments where
837        PCRE has not been installed from source.
839    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
840        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
841        library.
843    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
844        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
845        is not the first non-POSIX option to be added. Clearly some people find
846        these options useful.
848    17. If a caller to the POSIX matching function regexec() passes a non-zero
849        value for nmatch with a NULL value for pmatch, the value of
850        nmatch is forced to zero.
852    18. RunGrepTest did not have a test for the availability of the -u option of
853        the diff command, as RunTest does. It now checks in the same way as
854        RunTest, and also checks for the -b option.
856    19. If an odd number of negated classes containing just a single character
857        interposed, within parentheses, between a forward reference to a named
858        subpattern and the definition of the subpattern, compilation crashed with
859        an internal error, complaining that it could not find the referenced
860        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
861        [The bug was that it was starting one character too far in when skipping
862        over the character class, thus treating the ] as data rather than
863        terminating the class. This meant it could skip too much.]
865    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
866        /g option in pcretest when the pattern contains \K, which makes it possible
867        to have an empty string match not at the start, even when the pattern is
868        anchored. Updated pcretest and pcredemo to use this option.
870    21. If the maximum number of capturing subpatterns in a recursion was greater
871        than the maximum at the outer level, the higher number was returned, but
872        with unset values at the outer level. The correct (outer level) value is
873        now given.
875    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
876        PCRE did not set those parentheses (unlike Perl). I have now found a way to
877        make it do so. The string so far is captured, making this feature
878        compatible with Perl.
880    23. The tests have been re-organized, adding tests 11 and 12, to make it
881        possible to check the Perl 5.10 features against Perl 5.10.
883    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
884        pattern matches a fixed length string. PCRE did not allow this; now it
885        does. Neither allows recursion.
887    25. I finally figured out how to implement a request to provide the minimum
888        length of subject string that was needed in order to match a given pattern.
889        (It was back references and recursion that I had previously got hung up
890        on.) This code has now been added to pcre_study(); it finds a lower bound
891        to the length of subject needed. It is not necessarily the greatest lower
892        bound, but using it to avoid searching strings that are too short does give
893        some useful speed-ups. The value is available to calling programs via
894        pcre_fullinfo().
896    26. While implementing 25, I discovered to my embarrassment that pcretest had
897        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
898        study optimizations had never been tested with that matching function.
899        Oops. What is worse, even when it was passed study data, there was a bug in
900        pcre_dfa_exec() that meant it never actually used it. Double oops. There
901        were also very few tests of studied patterns with pcre_dfa_exec().
903    27. If (?| is used to create subpatterns with duplicate numbers, they are now
904        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
905        on the other side of the coin, they are no longer allowed to have different
906        names, because these cannot be distinguished in PCRE, and this has caused
907        confusion. (This is a difference from Perl.)
909    28. When duplicate subpattern names are present (necessarily with different
910        numbers, as required by 27 above), and a test is made by name in a
911        conditional pattern, either for a subpattern having been matched, or for
912        recursion in such a pattern, all the associated numbered subpatterns are
913        tested, and the overall condition is true if the condition is true for any
914        one of them. This is the way Perl works, and is also more like the way
915        testing by number works.
918    Version 7.9 11-Apr-09
919    ---------------------
921    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
922        (pcretest), all targets were linked against these libraries. This included
923        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
924        libraries. This caused unwanted dependencies to be created. This problem
925        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
926        pcretest is linked with readline.
928    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
929        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
930        moved outside it again, because FALSE and TRUE are already defined in AIX,
931        but BOOL is not.
933    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
934        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
936    4.  The pcregrep documentation said spaces were inserted as well as colons (or
937        hyphens) following file names and line numbers when outputting matching
938        lines. This is not true; no spaces are inserted. I have also clarified the
939        wording for the --colour (or --color) option.
941    5.  In pcregrep, when --colour was used with -o, the list of matching strings
942        was not coloured; this is different to GNU grep, so I have changed it to be
943        the same.
945    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
946        each matching line was coloured. Now it goes on to look for further matches
947        of any of the test patterns, which is the same behaviour as GNU grep.
949    7.  A pattern that could match an empty string could cause pcregrep to loop; it
950        doesn't make sense to accept an empty string match in pcregrep, so I have
951        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
952        seems to be how GNU grep behaves.
954    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
955        start or after a newline", because the conditional assertion was not being
956        correctly handled. The rule now is that both the assertion and what follows
957        in the first alternative must satisfy the test.
959    9.  If auto-callout was enabled in a pattern with a conditional group whose
960        condition was an assertion, PCRE could crash during matching, both with
961        pcre_exec() and pcre_dfa_exec().
963    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
964        used for matching.
966    11. Unicode property support in character classes was not working for
967        characters (bytes) greater than 127 when not in UTF-8 mode.
969    12. Added the -M command line option to pcretest.
971    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
973    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
975    16. Added comments and documentation about mis-use of no_arg in the C++
976        wrapper.
978    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
979        from Martin Jerabek that uses macro names for all relevant character and
980        string constants.
982    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
983        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
984        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
985        these, but not everybody uses configure.
987    19. A conditional group that had only one branch was not being correctly
988        recognized as an item that could match an empty string. This meant that an
989        enclosing group might also not be so recognized, causing infinite looping
990        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
991        with the subject "ab", where knowledge that the repeated group can match
992        nothing is needed in order to break the loop.
994    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
995        exec(), but without supplying a callout function, matching went wrong.
997    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
998        leak if the size of the offset vector was greater than 30. When the vector
999        is smaller, the saved offsets during recursion go onto a local stack
1000        vector, but for larger vectors malloc() is used. It was failing to free
1001        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1002        error, in fact).
1004    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1005        heapframe that is used only when UTF-8 support is enabled. This caused no
1006        problem, but was untidy.
1008    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1009        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1010        included within another project.
1012    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1013        slightly modified by me:
1015          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1016              not building pcregrep.
1018          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1019              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1021    25. Forward references, both numeric and by name, in patterns that made use of
1022        duplicate group numbers, could behave incorrectly or give incorrect errors,
1023        because when scanning forward to find the reference group, PCRE was not
1024        taking into account the duplicate group numbers. A pattern such as
1025        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1027    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1028        the feature of a custom pointer more persuasive (as requested by a user).
1030    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1031        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1032        pre-defined.
1034    28. Added support for (*UTF8) at the start of a pattern.
1036    29. Arrange for flags added by the "release type" setting in CMake to be shown
1037        in the configuration summary.
1040    Version 7.8 05-Sep-08
1041    ---------------------
1043    1.  Replaced UCP searching code with optimized version as implemented for Ad
1044        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1045        stage table and inline lookup instead of a function, giving speed ups of 2
1046        to 5 times on some simple patterns that I tested. Permission was given to
1047        distribute the MultiStage2.py script that generates the tables (it's not in
1048        the tarball, but is in the Subversion repository).
1050    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1051        scripts.
1053    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1054        a group with a zero qualifier. The result of the study could be incorrect,
1055        or the function might crash, depending on the pattern.
1057    4.  Caseless matching was not working for non-ASCII characters in back
1058        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1059        It now works when Unicode Property Support is available.
1061    5.  In pcretest, an escape such as \x{de} in the data was always generating
1062        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1063        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1064        truncation.
1066    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1068    7.  Added two (int) casts to pcregrep when printing the difference of two
1069        pointers, in case they are 64-bit values.
1071    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1072        test 2 if it fails.
1074    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1075        and a #define of that name to empty if it is not externally set. This is to
1076        allow users of MSVC to set it if necessary.
1078    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1079        the convenience functions in the pcre_get.c source file.
1081    11. An option change at the start of a pattern that had top-level alternatives
1082        could cause overwriting and/or a crash. This command provoked a crash in
1083        some environments:
1085          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1087        This potential security problem was recorded as CVE-2008-2371.
1089    12. For a pattern where the match had to start at the beginning or immediately
1090        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1091        pcre_dfa_exec() could read past the end of the passed subject if there was
1092        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1093        pcretest so that it places the subject at the end of its malloc-ed buffer.
1095    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1096        exec() might read past the end of the data buffer in UTF-8 mode.
1098    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1099        the data contained the byte 0x85 as part of a UTF-8 character within its
1100        first line. This applied both to normal and DFA matching.
1102    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1103        /^[^d]*?$/8 failed to match "abc".
1105    16. Added a missing copyright notice to pcrecpp_internal.h.
1107    17. Make it more clear in the documentation that values returned from
1108        pcre_exec() in ovector are byte offsets, not character counts.
1110    18. Tidied a few places to stop certain compilers from issuing warnings.
1112    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1113        supplied by Stefan Weber. I made a further small update for 7.8 because
1114        there is a change of source arrangements: the pcre_searchfuncs.c module is
1115        replaced by pcre_ucd.c.
1118    Version 7.7 07-May-08
1119    ---------------------
1121    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1122        a string to a long long, pretend we don't even have a long long." This is
1123        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1125    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1126        pre-7.6 versions, which defined a global no_arg variable instead of putting
1127        it in the RE class. (See also #8 below.)
1129    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1130        Lopes.
1132    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1134        (1) The include/exclude patterns were being applied to the whole pathnames
1135            of files, instead of just to the final components.
1137        (2) If there was more than one level of directory, the subdirectories were
1138            skipped unless they satisfied the include/exclude conditions. This is
1139            inconsistent with GNU grep (and could even be seen as contrary to the
1140            pcregrep specification - which I improved to make it absolutely clear).
1141            The action now is always to scan all levels of directory, and just
1142            apply the include/exclude patterns to regular files.
1144    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1145        --exclude_dir in the tests to avoid scanning .svn directories.
1147    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1148        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1149        doesn't support NULs in patterns.
1151    7.  Added some missing "const"s to declarations of static tables in
1152        pcre_compile.c and pcre_dfa_exec.c.
1154    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1155        caused by fix #2  above. (Subsequently also a second patch to fix the
1156        first patch. And a third patch - this was a messy problem.)
1158    9.  Applied Craig's patch to remove the use of push_back().
1160    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1161        matching function regexec().
1163    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1164        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1165        references. PCRE supports relative numbers with this syntax (I don't think
1166        Oniguruma does).
1168    12. Previously, a group with a zero repeat such as (...){0} was completely
1169        omitted from the compiled regex. However, this means that if the group
1170        was called as a subroutine from elsewhere in the pattern, things went wrong
1171        (an internal error was given). Such groups are now left in the compiled
1172        pattern, with a new opcode that causes them to be skipped at execution
1173        time.
1175    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1176        to the way PCRE behaves:
1178        (a) A lone ] character is dis-allowed (Perl treats it as data).
1180        (b) A back reference to an unmatched subpattern matches an empty string
1181            (Perl fails the current match path).
1183        (c) A data ] in a character class must be notated as \] because if the
1184            first data character in a class is ], it defines an empty class. (In
1185            Perl it is not possible to have an empty class.) The empty class []
1186            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1187            The negative empty class [^] matches any one character, independently
1188            of the DOTALL setting.
1190    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1191        non-existent subpattern following a character class starting with ']' and
1192        containing () gave an internal compiling error instead of "reference to
1193        non-existent subpattern". Fortunately, when the pattern did exist, the
1194        compiled code was correct. (When scanning forwards to check for the
1195        existencd of the subpattern, it was treating the data ']' as terminating
1196        the class, so got the count wrong. When actually compiling, the reference
1197        was subsequently set up correctly.)
1199    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1200        it was being rejected as not supported by pcre_dfa_exec(), even though
1201        other assertions are supported. I have made pcre_dfa_exec() support
1202        (*FAIL).
1204    16. The implementation of 13c above involved the invention of a new opcode,
1205        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1206        cannot be changed at match time, I realized I could make a small
1207        improvement to matching performance by compiling OP_ALLANY instead of
1208        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1209        on the OP_ANY path.
1211    17. Compiling pcretest on Windows with readline support failed without the
1212        following two fixes: (1) Make the unistd.h include conditional on
1213        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1215    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1216        ncurses library to be included for pcretest when ReadLine support is
1217        requested, but also to allow for it to be overridden. This patch came from
1218        Daniel Bergström.
1220    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1221        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1222        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1223        spotting this.
1226    Version 7.6 28-Jan-08
1227    ---------------------
1229    1.  A character class containing a very large number of characters with
1230        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1231        overflow.
1233    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1234        HAVE_LONG_LONG is not defined.
1236    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1237        bring them up to date and include new features. This patch includes:
1239        - Fixed PH's badly added libz and libbz2 support.
1240        - Fixed a problem with static linking.
1241        - Added pcredemo. [But later removed - see 7 below.]
1242        - Fixed dftables problem and added an option.
1243        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1244            HAVE_LONG_LONG.
1245        - Added readline support for pcretest.
1246        - Added an listing of the option settings after cmake has run.
1248    4.  A user submitted a patch to Makefile that makes it easy to create
1249        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1250        Makefile.am that cause it to include this special target, without
1251        affecting anything else. Note that the same mingw target plus all
1252        the other distribution libraries and programs are now supported
1253        when configuring with CMake (see 6 below) instead of with
1254        Configure/Make.
1256    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1257        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1258        exported in the Windows port". It has not yet been confirmed that the patch
1259        solves the problem, but it does no harm.
1261    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1262        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1263        with CMake, and also correct the comment about stack recursion.
1265    7.  Remove the automatic building of pcredemo from the ./configure system and
1266        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1267        of a program that users should build themselves after PCRE is installed, so
1268        building it automatically is not really right. What is more, it gave
1269        trouble in some build environments.
1271    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1274    Version 7.5 10-Jan-08
1275    ---------------------
1277    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1278        values in parens when parsing an RE using the C++ wrapper."
1280    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1281        Characters greater than 255 were excluded from the class instead of being
1282        included.
1284    3.  The same bug as (2) above applied to negated POSIX classes such as
1285        [:^space:].
1287    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1288        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1289        I have changed it.
1291    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1292        first named subpattern) and a construct such as (?&a) would reference the
1293        first named subpattern whose name started with "a" (in other words, the
1294        length check was missing). Both these problems are fixed. "Subpattern name
1295        expected" is now given for (?&) (a zero-length name), and this patch also
1296        makes it give the same error for \k'' (previously it complained that that
1297        was a reference to a non-existent subpattern).
1299    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1300        this is right because (?- can be followed by option settings as well as by
1301        digits. I have, however, made the messages clearer.
1303    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1304        than the number used in the conditional) now cause a compile-time error.
1305        This is actually not compatible with Perl, which accepts such patterns, but
1306        treats the conditional as always being FALSE (as PCRE used to), but it
1307        seems to me that giving a diagnostic is better.
1309    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1310        and messages.
1312    9.  Fix two occurrences of "backslash" in comments that should have been
1313        "backspace".
1315    10. Remove two redundant lines of code that can never be obeyed (their function
1316        was moved elsewhere).
1318    11. The program that makes PCRE's Unicode character property table had a bug
1319        which caused it to generate incorrect table entries for sequences of
1320        characters that have the same character type, but are in different scripts.
1321        It amalgamated them into a single range, with the script of the first of
1322        them. In other words, some characters were in the wrong script. There were
1323        thirteen such cases, affecting characters in the following ranges:
1325          U+002b0 - U+002c1
1326          U+0060c - U+0060d
1327          U+0061e - U+00612
1328          U+0064b - U+0065e
1329          U+0074d - U+0076d
1330          U+01800 - U+01805
1331          U+01d00 - U+01d77
1332          U+01d9b - U+01dbf
1333          U+0200b - U+0200f
1334          U+030fc - U+030fe
1335          U+03260 - U+0327f
1336          U+0fb46 - U+0fbb1
1337          U+10450 - U+1049d
1339    12. The -o option (show only the matching part of a line) for pcregrep was not
1340        compatible with GNU grep in that, if there was more than one match in a
1341        line, it showed only the first of them. It now behaves in the same way as
1342        GNU grep.
1344    13. If the -o and -v options were combined for pcregrep, it printed a blank
1345        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1346        does the same. The return code can be used to tell if there were any
1347        non-matching lines.
1349    14. Added --file-offsets and --line-offsets to pcregrep.
1351    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1352        infinitely looping recursion. The bug was that positive lookaheads were not
1353        being skipped when checking for a possible empty match (negative lookaheads
1354        and both kinds of lookbehind were skipped).
1356    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1357        inclusion of <windows.h> to before rather than after the definition of
1358        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1360    17. Specifying a possessive quantifier with a specific limit for a Unicode
1361        character property caused pcre_compile() to compile bad code, which led at
1362        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1363        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1364        caused the error; without that there was no problem.
1366    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1368    19. Added --enable-pcretest-libreadline.
1370    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1371        RE::GlobalReplace(). As a result, the number of replacements returned was
1372        double what it should be. I removed one of the increments, but Craig sent a
1373        later patch that removed the other one (the right fix) and added unit tests
1374        that check the return values (which was not done before).
1376    21. Several CMake things:
1378        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1379            the names libpcre and libpcreposix, not just pcre and pcreposix.
1381        (2) The above change means that pcretest and pcregrep are now correctly
1382            linked with the newly-built libraries, not previously installed ones.
1386    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1387        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1388        UTF-8 newline character). The key issue is that the pattern starts .*;
1389        this means that the match must be either at the beginning, or after a
1390        newline. The bug was in the code for advancing after a failed match and
1391        checking that the new position followed a newline. It was not taking
1392        account of UTF-8 characters correctly.
1394    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1395        character classes. PCRE was not treating the sequence [:...:] as a
1396        character class unless the ... were all letters. Perl, however, seems to
1397        allow any characters between [: and :], though of course it rejects as
1398        unknown any "names" that contain non-letters, because all the known class
1399        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1400        for example, whereas PCRE did not - it did not recognize a POSIX character
1401        class. This seemed a bit dangerous, so the code has been changed to be
1402        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1403        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1404        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1405        Perl does, and where it didn't before.
1407    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1408        Windows environments %n is disabled by default.
1411    Version 7.4 21-Sep-07
1412  ---------------------  ---------------------
1414  1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This  1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
# Line 32  Version 7.4 10-Sep-07 Line 1439  Version 7.4 10-Sep-07
1439      compatibility, even though it is no longer used.      compatibility, even though it is no longer used.
1441  7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and  7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1442      strtoull to pcrecpp.cc to select the available functions in WIN32 when the      strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1443      windows.h file is present (where different names are used).      windows.h file is present (where different names are used). [This was
1444        reversed later after testing - see 16 below.]
1446  8.  Changed all #include <config.h> to #include "config.h". There were also  8.  Changed all #include <config.h> to #include "config.h". There were also
1447      some further <pcre.h> cases that I changed to "pcre.h".      some further <pcre.h> cases that I changed to "pcre.h".
# Line 60  Version 7.4 10-Sep-07 Line 1468  Version 7.4 10-Sep-07
1469  12. Updated the tests so that they work when \R is defaulted to ANYCRLF.  12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1471    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1472        checked only for CRLF.
1474    14. Added casts to pcretest.c to avoid compiler warnings.
1476    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1478    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1479        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1480        entirely. This removes changes made in 7 above.
1482    17. The CMake files have been updated, and there is now more information about
1483        building with CMake in the NON-UNIX-USE document.
1486  Version 7.3 28-Aug-07  Version 7.3 28-Aug-07
1487  ---------------------  ---------------------

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