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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.1 12-Mar-07  Version 8.32 11-November-2012
5    -----------------------------
7    1.  Improved JIT compiler optimizations for first character search and single
8        character iterators.
10    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11        Patch by Daniel Richard G.
13    3.  Single character iterator optimizations in the JIT compiler.
15    4.  Improved JIT compiler optimizations for character ranges.
17    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
18        Reported by Giuseppe D'Angelo.
20    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
21        of a line, was being set incorrectly in cases where .* appeared inside
22        atomic brackets at the start of a pattern, or where there was a subsequent
23        *PRUNE or *SKIP.
25    7.  Improved instruction cache flush for POWER/PowerPC.
26        Patch by Daniel Richard G.
28    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
29        grep:
31        (a) There is now no limit to the number of patterns to be matched.
33        (b) An error is given if a pattern is too long.
35        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
36            are now supported.
38        (d) --exclude-from and --include-from (multiple use) have been added.
40        (e) Exclusions and inclusions now apply to all files and directories, not
41            just to those obtained from scanning a directory recursively.
43        (f) Multiple uses of -f and --file-list are now supported.
45        (g) In a Windows environment, the default for -d has been changed from
46            "read" (the GNU grep default) to "skip", because otherwise the presence
47            of a directory in the file list provokes an error.
49        (h) The documentation has been revised and clarified in places.
51    9.  Improve the matching speed of capturing brackets.
53    10. Changed the meaning of \X so that it now matches a Unicode extended
54        grapheme cluster.
56    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
57        out POSIX threads when JIT support is configured.
59    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
61    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
62        structure could go wrong in environments where size_t is not the same size
63        as int.
65    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
66        set.
68    15. The EBCDIC support had decayed; later updates to the code had included
69        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
70        general tidy up of EBCDIC-related issues, and the documentation was also
71        not quite right. There is now a test that can be run on ASCII systems to
72        check some of the EBCDIC-related things (but is it not a full test).
74    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
75        in a small tidy to the code.
77    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
79    18. If the --only-matching (-o) option in pcregrep is specified multiple
80        times, each one causes appropriate output. For example, -o1 -o2 outputs the
81        substrings matched by the 1st and 2nd capturing parentheses. A separating
82        string can be specified by --om-separator (default empty).
84    19. Improving the first n character searches.
86    20. Turn case lists for horizontal and vertical white space into macros so that
87        they are defined only once.
89    21. This set of changes together give more compatible Unicode case-folding
90        behaviour for characters that have more than one other case when UCP
91        support is available.
93        (a) The Unicode property table now has offsets into a new table of sets of
94            three or more characters that are case-equivalent. The MultiStage2.py
95            script that generates these tables (the pcre_ucd.c file) now scans
96            CaseFolding.txt instead of UnicodeData.txt for character case
97            information.
99        (b) The code for adding characters or ranges of characters to a character
100            class has been abstracted into a generalized function that also handles
101            case-independence. In UTF-mode with UCP support, this uses the new data
102            to handle characters with more than one other case.
104        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
105            whose other case is greater than 256 are now correctly matched
106            caselessly. Previously, the high codepoint matched the low one, but not
107            vice versa.
109        (d) The processing of \h, \H, \v, and \ in character classes now makes use
110            of the new class addition function, using character lists defined as
111            macros alongside the case definitions of 20 above.
113        (e) Caseless back references now work with characters that have more than
114            one other case.
116        (f) General caseless matching of characters with more than one other case
117            is supported.
119    22. Unicode character properties were updated from Unicode 6.2.0
121    23. Improved CMake support under Windows. Patch by Daniel Richard G.
123    24. Add support for 32-bit character strings, and UTF-32
125    25. Major JIT compiler update (code refactoring and bugfixing).
126        Experimental Sparc 32 support is added.
128    26. Applied a modified version of Daniel Richard G's patch to create
129        pcre.h.generic and config.h.generic by "make" instead of in the
130        PrepareRelease script.
132    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
133        pcre_compile.c when checking for a zero character.
135    28. Introducing a native interface for JIT. Through this interface, the compiled
136        machine code can be directly executed. The purpose of this interface is to
137        provide fast pattern matching, so several sanity checks are not performed.
138        However, feature tests are still performed. The new interface provides
139        1.4x speedup compared to the old one.
141    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
142        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
143        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
145    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
146        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
147        the "old" RFC 2279). Instead, it ended up passing a negative length to
148        pcre_exec().
150    31. Add support for GCC's visibility feature to hide internal functions.
152    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
153        "unknown -C option" after outputting 0 or 1.
155    33. There is now support for generating a code coverage report for the test
156        suite in environments where gcc is the compiler and lcov is installed. This
157        is mainly for the benefit of the developers.
159    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
160        unaddressable using valgrind annotations, allowing valgrind to detect
161        invalid memory accesses. This is mainly for the benefit of the developers.
164    Version 8.31 06-July-2012
165    -------------------------
167    1.  Fixing a wrong JIT test case and some compiler warnings.
169    2.  Removed a bashism from the RunTest script.
171    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
172        to unsigned type, result still unsigned" that was given by an MS compiler
173        on encountering the code "-sizeof(xxx)".
175    4.  Partial matching support is added to the JIT compiler.
177    5.  Fixed several bugs concerned with partial matching of items that consist
178        of more than one character:
180        (a) /^(..)\1/ did not partially match "aba" because checking references was
181            done on an "all or nothing" basis. This also applied to repeated
182            references.
184        (b) \R did not give a hard partial match if \r was found at the end of the
185            subject.
187        (c) \X did not give a hard partial match after matching one or more
188            characters at the end of the subject.
190        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
191            a partial match for the string "\r".
193        (e) When newline was set to CRLF, the metacharacter "." did not recognize
194            a partial match for a CR character at the end of the subject string.
196    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
197        running pcretest, the text "(JIT)" added to the output whenever JIT is
198        actually used to run the match.
200    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
201        or /S+[+] with a digit between 1 and 7.
203    8.  OP_NOT now supports any UTF character not just single-byte ones.
205    9.  (*MARK) control verb is now supported by the JIT compiler.
207    10. The command "./RunTest list" lists the available tests without actually
208        running any of them. (Because I keep forgetting what they all are.)
212    12. Applied a (slightly modified) user-supplied patch that improves performance
213        when the heap is used for recursion (compiled with --disable-stack-for-
214        recursion). Instead of malloc and free for each heap frame each time a
215        logical recursion happens, frames are retained on a chain and re-used where
216        possible. This sometimes gives as much as 30% improvement.
218    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
219        call.
221    14. As documented, (*COMMIT) is now confined to within a positive assertion.
223    15. It is now possible to link pcretest with libedit as an alternative to
224        libreadline.
226    16. (*COMMIT) control verb is now supported by the JIT compiler.
228    17. The Unicode data tables have been updated to Unicode 6.1.0.
230    18. Added --file-list option to pcregrep.
232    19. Added binary file support to pcregrep, including the -a, --binary-files,
233        -I, and --text options.
235    20. The madvise function is renamed for posix_madvise for QNX compatibility
236        reasons. Fixed by Giuseppe D'Angelo.
238    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
240    22. Changed the option for creating symbolic links for 16-bit man pages from
241        -s to -sf so that re-installing does not cause issues.
243    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
245    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
246        matches in certain environments (the workspace was not being correctly
247        retained). Also added to pcre_dfa_exec() a simple plausibility check on
248        some of the workspace data at the beginning of a restart.
250    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
251        was not doing so when it should - probably a typo introduced by SVN 528
252        (change 8.10/14).
254    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
255        \w+ when the character tables indicated that \x{c4} was a word character.
256        There were several related cases, all because the tests for doing a table
257        lookup were testing for characters less than 127 instead of 255.
259    27. If a pattern contains capturing parentheses that are not used in a match,
260        their slots in the ovector are set to -1. For those that are higher than
261        any matched groups, this happens at the end of processing. In the case when
262        there were back references that the ovector was too small to contain
263        (causing temporary malloc'd memory to be used during matching), and the
264        highest capturing number was not used, memory off the end of the ovector
265        was incorrectly being set to -1. (It was using the size of the temporary
266        memory instead of the true size.)
268    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
269        ovector size, it uses memory at the end of the block that it has got.
271    29. Check for an overlong MARK name and give an error at compile time. The
272        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
274    30. JIT compiler update.
276    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
277        Rill for the patch.
279    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
281    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
283    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
284        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
285        was enabled.
287    35. Improve JIT code generation for greedy plus quantifier.
289    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
290        1 to "aa" instead of to an empty string. The bug affected repeated groups
291        that could potentially match an empty string.
293    37. Optimizing single character iterators in JIT.
295    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
296        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
297        codepoints that are too big for the mode are faulted, and in a UTF mode,
298        disallowed codepoints are also faulted.
300    39. If PCRE was compiled with UTF support, in three places in the DFA
301        matcher there was code that should only have been obeyed in UTF mode, but
302        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
303        processing when bytes with values greater than 127 were present. In 16-bit
304        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
305        both cases the values are those that cannot be the first data item in a UTF
306        character. The three items that might have provoked this were recursions,
307        possessively repeated groups, and atomic groups.
309    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
310        and pcregrep, because some OS require shared objects to be explicitly
311        passed to ld, causing the link step to fail if they are not.
313    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
314        mode, patterns that started with \h* or \R* might be incorrectly matched.
317    Version 8.30 04-February-2012
318    -----------------------------
320    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
321        name is defined in ctype.h.
323    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
324        only in quite long subpatterns.
326    3.  Removed the function pcre_info(), which has been obsolete and deprecated
327        since it was replaced by pcre_fullinfo() in February 2000.
329    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
330        match a (*MARK), and the match failed at the start of the subject, a
331        reference to memory before the start of the subject could occur. This bug
332        was introduced by fix 17 of release 8.21.
334    5.  A reference to an unset group with zero minimum repetition was giving
335        totally wrong answers (in non-JavaScript-compatibility mode). For example,
336        /(another)?(\1?)test/ matched against "hello world test". This bug was
337        introduced in release 8.13.
339    6.  Add support for 16-bit character strings (a large amount of work involving
340        many changes and refactorings).
342    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
343        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
344        from a file.
346    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
347        rounding is not applied in this particular case).
349    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
350        if they appear, or are escaped, in patterns.
352    10. Get rid of a number of -Wunused-but-set-variable warnings.
354    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
355        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
356        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
357        also returns the mark "x". This bug applied to capturing parentheses,
358        non-capturing parentheses, and atomic parentheses. It also applied to some
359        assertions.
361    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
362        information out of configure.ac instead of relying on pcre.h.generic, which
363        is not stored in the repository.
365    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
366        -lreadline.
368    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
370    15. Applied Graycode's patch to put the top-level frame on the stack rather
371        than the heap when not using the stack for recursion. This gives a
372        performance improvement in many cases when recursion is not deep.
374    16. Experimental code added to "pcretest -C" to output the stack frame size.
377    Version 8.21 12-Dec-2011
378    ------------------------
380    1.  Updating the JIT compiler.
382    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
383        are added as well.
385    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
386        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
387        calling _pcre_jit_exec. Some extra comments are added.
389    4.  (*MARK) settings inside atomic groups that do not contain any capturing
390        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
391        was introduced by change 18 for 8.20.
393    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
394        ECMA-262 standard.
396    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
397        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
398        This bug was probably introduced by change 9 of 8.13.
400    7.  While fixing 6 above, I noticed that a number of other items were being
401        incorrectly rejected as "not fixed length". This arose partly because newer
402        opcodes had not been added to the fixed-length checking code. I have (a)
403        corrected the bug and added tests for these items, and (b) arranged for an
404        error to occur if an unknown opcode is encountered while checking for fixed
405        length instead of just assuming "not fixed length". The items that were
406        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
407        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
408        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
410    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
411        being incorrectly compiled and would have given unpredicatble results.
413    9.  A possessively repeated subpattern with minimum repeat count greater than
414        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
415        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
416        the first (A) could occur when it should not.
418    10. Add a cast and remove a redundant test from the code.
420    11. JIT should use pcre_malloc/pcre_free for allocation.
422    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
423        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
424        is anything other than /usr, -L is still shown).
426    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
428    14. Perl does not support \N without a following name in a [] class; PCRE now
429        also gives an error.
431    15. If a forward reference was repeated with an upper limit of around 2000,
432        it caused the error "internal error: overran compiling workspace". The
433        maximum number of forward references (including repeats) was limited by the
434        internal workspace, and dependent on the LINK_SIZE. The code has been
435        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
436        the default depends on LINK_SIZE. There is a new upper limit (for safety)
437        of around 200,000 forward references. While doing this, I also speeded up
438        the filling in of repeated forward references.
440    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
441        incorrectly expecting the subject to contain another "a" after the start.
443    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
444        in the match, the SKIP should be ignored. This was not happening; instead
445        the SKIP was being treated as NOMATCH. For patterns such as
446        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
447        tested.
449    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
450        now much more compatible with Perl, in particular in cases where the result
451        is a non-match for a non-anchored pattern. For example, if
452        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
453        "m", where previously it did not return a name. A side effect of this
454        change is that for partial matches, the last encountered mark name is
455        returned, as for non matches. A number of tests that were previously not
456        Perl-compatible have been moved into the Perl-compatible test files. The
457        refactoring has had the pleasing side effect of removing one argument from
458        the match() function, thus reducing its stack requirements.
460    19. If the /S+ option was used in pcretest to study a pattern using JIT,
461        subsequent uses of /S (without +) incorrectly behaved like /S+.
463    21. Retrieve executable code size support for the JIT compiler and fixing
464        some warnings.
466    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
467        not work when the shorter character appeared right at the end of the
468        subject string.
470    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
471        systems.
473    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
474        output it when the /M option is used in pcretest.
476    25. The CheckMan script was not being included in the distribution. Also, added
477        an explicit "perl" to run Perl scripts from the PrepareRelease script
478        because this is reportedly needed in Windows.
480    26. If study data was being save in a file and studying had not found a set of
481        "starts with" bytes for the pattern, the data written to the file (though
482        never used) was taken from uninitialized memory and so caused valgrind to
483        complain.
485    27. Updated RunTest.bat as provided by Sheri Pierce.
487    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
489    29. Computation of memory usage for the table of capturing group names was
490        giving an unnecessarily large value.
493    Version 8.20 21-Oct-2011
494    ------------------------
496    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
497        a POSIX class. After further experiments with Perl, which convinced me that
498        Perl has bugs and confusions, a closing square bracket is no longer allowed
499        in a POSIX name. This bug also affected patterns with classes that started
500        with full stops.
502    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
503        captured substring, but while checking the failing first alternative,
504        substring 1 is temporarily captured. If the output vector supplied to
505        pcre_exec() was not big enough for this capture, the yield of the function
506        was still zero ("insufficient space for captured substrings"). This cannot
507        be totally fixed without adding another stack variable, which seems a lot
508        of expense for a edge case. However, I have improved the situation in cases
509        such as /(a)(b)x|abc/ matched against "abc", where the return code
510        indicates that fewer than the maximum number of slots in the ovector have
511        been set.
513    3.  Related to (2) above: when there are more back references in a pattern than
514        slots in the output vector, pcre_exec() uses temporary memory during
515        matching, and copies in the captures as far as possible afterwards. It was
516        using the entire output vector, but this conflicts with the specification
517        that only 2/3 is used for passing back captured substrings. Now it uses
518        only the first 2/3, for compatibility. This is, of course, another edge
519        case.
521    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
522        main code base, and can be used by building with --enable-jit. When this is
523        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
524        runtime --no-jit option is given.
526    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
527        ovector, the return from the function was zero, implying that there were
528        other matches that did not fit. The correct "exactly full" value is now
529        returned.
531    6.  If a subpattern that was called recursively or as a subroutine contained
532        (*PRUNE) or any other control that caused it to give a non-standard return,
533        invalid errors such as "Error -26 (nested recursion at the same subject
534        position)" or even infinite loops could occur.
536    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
537        computing the minimum length on reaching *ACCEPT, and so ended up with the
538        wrong value of 1 rather than 0. Further investigation indicates that
539        computing a minimum subject length in the presence of *ACCEPT is difficult
540        (think back references, subroutine calls), and so I have changed the code
541        so that no minimum is registered for a pattern that contains *ACCEPT.
543    8.  If (*THEN) was present in the first (true) branch of a conditional group,
544        it was not handled as intended. [But see 16 below.]
546    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
547        Sheri Pierce.
549    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
550        the first byte in a match must be "a".
552    11. Change 17 for 8.13 increased the recursion depth for patterns like
553        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
554        pattern contains any instances of (*THEN). If it does not, the old
555        optimizations are restored. It would be nice to do this on a per-group
556        basis, but at the moment that is not feasible.
558    12. In some environments, the output of pcretest -C is CRLF terminated. This
559        broke RunTest's code that checks for the link size. A single white space
560        character after the value is now allowed for.
562    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
563        For "fr", it uses the Windows-specific input and output files.
565    14. If (*THEN) appeared in a group that was called recursively or as a
566        subroutine, it did not work as intended. [But see next item.]
568    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
569        pattern fragments (but not containing any | characters). If A and B are
570        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
571        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
572        D. In other words, Perl considers parentheses that do not contain any |
573        characters to be part of a surrounding alternative, whereas PCRE was
574        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
575        differently. PCRE now behaves in the same way as Perl, except in the case
576        of subroutine/recursion calls such as (?1) which have in any case always
577        been different (but PCRE had them first :-).
579    16. Related to 15 above: Perl does not treat the | in a conditional group as
580        creating alternatives. Such a group is treated in the same way as an
581        ordinary group without any | characters when processing (*THEN). PCRE has
582        been changed to match Perl's behaviour.
584    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
585        RunGrepTest script failed.
587    18. Change 22 for version 13 caused atomic groups to use more stack. This is
588        inevitable for groups that contain captures, but it can lead to a lot of
589        stack use in large patterns. The old behaviour has been restored for atomic
590        groups that do not contain any capturing parentheses.
592    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
593        suppress the check for a minimum subject length at run time. (If it was
594        given to pcre_exec() or pcre_dfa_exec() it did work.)
596    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
597        fail to work when decoding hex characters in data strings in EBCDIC
598        environments.
600    21. It appears that in at least one Mac OS environment, the isxdigit() function
601        is implemented as a macro that evaluates to its argument more than once,
602        contravening the C 90 Standard (I haven't checked a later standard). There
603        was an instance in pcretest which caused it to go wrong when processing
604        \x{...} escapes in subject strings. The has been rewritten to avoid using
605        things like p++ in the argument of isxdigit().
608    Version 8.13 16-Aug-2011
609    ------------------------
611    1.  The Unicode data tables have been updated to Unicode 6.0.0.
613    2.  Two minor typos in pcre_internal.h have been fixed.
615    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
616        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
617        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
619    4.  There were a number of related bugs in the code for matching backrefences
620        caselessly in UTF-8 mode when codes for the characters concerned were
621        different numbers of bytes. For example, U+023A and U+2C65 are an upper
622        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
623        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
624        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
625        2-byte code at the end of the subject (it thought there wasn't enough data
626        left).
628    5.  Comprehensive information about what went wrong is now returned by
629        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
630        as the output vector has at least 2 elements. The offset of the start of
631        the failing character and a reason code are placed in the vector.
633    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
634        now returned is for the first byte of the failing character, instead of the
635        last byte inspected. This is an incompatible change, but I hope it is small
636        enough not to be a problem. It makes the returned offset consistent with
637        pcre_exec() and pcre_dfa_exec().
639    7.  pcretest now gives a text phrase as well as the error number when
640        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
641        failure, the offset and reason code are output.
643    8.  When \R was used with a maximizing quantifier it failed to skip backwards
644        over a \r\n pair if the subsequent match failed. Instead, it just skipped
645        back over a single character (\n). This seems wrong (because it treated the
646        two characters as a single entity when going forwards), conflicts with the
647        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
648        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
649        has been changed.
651    9.  Some internal refactoring has changed the processing so that the handling
652        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
653        time (the PCRE_DOTALL option was changed this way some time ago: version
654        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
655        which was always a bit of a fudge. It also means that there is one less
656        argument for the match() function, which reduces its stack requirements
657        slightly. This change also fixes an incompatibility with Perl: the pattern
658        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
660    10. More internal refactoring has drastically reduced the number of recursive
661        calls to match() for possessively repeated groups such as (abc)++ when
662        using pcre_exec().
664    11. While implementing 10, a number of bugs in the handling of groups were
665        discovered and fixed:
667        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
668        (a|)*(?1) gave a compile-time internal error.
669        ((a|)+)+  did not notice that the outer group could match an empty string.
670        (^a|^)+   was not marked as anchored.
671        (.*a|.*)+ was not marked as matching at start or after a newline.
673    12. Yet more internal refactoring has removed another argument from the match()
674        function. Special calls to this function are now indicated by setting a
675        value in a variable in the "match data" data block.
677    13. Be more explicit in pcre_study() instead of relying on "default" for
678        opcodes that mean there is no starting character; this means that when new
679        ones are added and accidentally left out of pcre_study(), testing should
680        pick them up.
682    14. The -s option of pcretest has been documented for ages as being an old
683        synonym of -m (show memory usage). I have changed it to mean "force study
684        for every regex", that is, assume /S for every regex. This is similar to -i
685        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
686        using it. It makes it easier to run collections of tests with and without
687        study enabled, and thereby test pcre_study() more easily. All the standard
688        tests are now run with and without -s (but some patterns can be marked as
689        "never study" - see 20 below).
691    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
692        restoration of the capturing data to the outer values was not happening
693        correctly.
695    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
696        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
697        pattern had matched an empty string, and so incorrectly returned a no
698        match.
700    17. There was optimizing code for the last branch of non-capturing parentheses,
701        and also for the obeyed branch of a conditional subexpression, which used
702        tail recursion to cut down on stack usage. Unfortunately, now that there is
703        the possibility of (*THEN) occurring in these branches, tail recursion is
704        no longer possible because the return has to be checked for (*THEN). These
705        two optimizations have therefore been removed. [But see 8.20/11 above.]
707    18. If a pattern containing \R was studied, it was assumed that \R always
708        matched two bytes, thus causing the minimum subject length to be
709        incorrectly computed because \R can also match just one byte.
711    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
712        was incorrectly computed.
714    20. If /S is present twice on a test pattern in pcretest input, it now
715        *disables* studying, thereby overriding the use of -s on the command line
716        (see 14 above). This is necessary for one or two tests to keep the output
717        identical in both cases.
719    21. When (*ACCEPT) was used in an assertion that matched an empty string and
720        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
722    22. When an atomic group that contained a capturing parenthesis was
723        successfully matched, but the branch in which it appeared failed, the
724        capturing was not being forgotten if a higher numbered group was later
725        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
726        group 1 to "a", when in fact it should be unset. This applied to multi-
727        branched capturing and non-capturing groups, repeated or not, and also to
728        positive assertions (capturing in negative assertions does not happen
729        in PCRE) and also to nested atomic groups.
731    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
732        subject after a captured substring, to make it easier to tell which of a
733        number of identical substrings has been captured.
735    24. The way atomic groups are processed by pcre_exec() has been changed so that
736        if they are repeated, backtracking one repetition now resets captured
737        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
738        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
739        "aaa". Previously, it would have been "a". As part of this code
740        refactoring, the way recursive calls are handled has also been changed.
742    25. If an assertion condition captured any substrings, they were not passed
743        back unless some other capturing happened later. For example, if
744        (?(?=(a))a) was matched against "a", no capturing was returned.
746    26. When studying a pattern that contained subroutine calls or assertions,
747        the code for finding the minimum length of a possible match was handling
748        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
749        group 1 called group 2 while simultaneously a separate group 2 called group
750        1). A stack overflow occurred in this case. I have fixed this by limiting
751        the recursion depth to 10.
753    27. Updated RunTest.bat in the distribution to the version supplied by Tom
754        Fortmann. This supports explicit test numbers on the command line, and has
755        argument validation and error reporting.
757    28. An instance of \X with an unlimited repeat could fail if at any point the
758        first character it looked at was a mark character.
760    29. Some minor code refactoring concerning Unicode properties and scripts
761        should reduce the stack requirement of match() slightly.
763    30. Added the '=' option to pcretest to check the setting of unused capturing
764        slots at the end of the pattern, which are documented as being -1, but are
765        not included in the return count.
767    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
768        compiled something random. Now it gives a compile-time error (as does
769        Perl).
771    32. A *MARK encountered during the processing of a positive assertion is now
772        recorded and passed back (compatible with Perl).
774    33. If --only-matching or --colour was set on a pcregrep call whose pattern
775        had alternative anchored branches, the search for a second match in a line
776        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
777        matched the line "0102" twice. The same bug affected patterns that started
778        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
779        twice.
781    34. Previously, PCRE did not allow quantification of assertions. However, Perl
782        does, and because of capturing effects, quantifying parenthesized
783        assertions may at times be useful. Quantifiers are now allowed for
784        parenthesized assertions.
786    35. A minor code tidy in pcre_compile() when checking options for \R usage.
788    36. \g was being checked for fancy things in a character class, when it should
789        just be a literal "g".
791    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
792        appearance of a nested POSIX class supersedes an apparent external class.
793        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
794        unescaped square brackets may also appear as part of class names. For
795        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
796        more like Perl. (But see 8.20/1 above.)
798    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
799        was because it thought it was \N{name}, which is not supported).
801    39. Add minix to OS list not supporting the -S option in pcretest.
803    40. PCRE tries to detect cases of infinite recursion at compile time, but it
804        cannot analyze patterns in sufficient detail to catch mutual recursions
805        such as ((?1))((?2)). There is now a runtime test that gives an error if a
806        subgroup is called recursively as a subpattern for a second time at the
807        same position in the subject string. In previous releases this might have
808        been caught by the recursion limit, or it might have run out of stack.
810    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
811        happen only once. PCRE was, however incorrectly giving a compile time error
812        "recursive call could loop indefinitely" because it cannot analyze the
813        pattern in sufficient detail. The compile time test no longer happens when
814        PCRE is compiling a conditional subpattern, but actual runaway loops are
815        now caught at runtime (see 40 above).
817    42. It seems that Perl allows any characters other than a closing parenthesis
818        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
819        has been changed to be the same.
821    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
822        as not to get warnings when autogen.sh is called. Also changed
823        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
825    44. To help people who use pcregrep to scan files containing exceedingly long
826        lines, the following changes have been made:
828        (a) The default value of the buffer size parameter has been increased from
829            8K to 20K. (The actual buffer used is three times this size.)
831        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
832            PCRE is built.
834        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
835            to be set at run time.
837        (d) Numerical values in pcregrep options can be followed by K or M, for
838            example --buffer-size=50K.
840        (e) If a line being scanned overflows pcregrep's buffer, an error is now
841            given and the return code is set to 2.
843    45. Add a pointer to the latest mark to the callout data block.
845    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
846        partial match of an empty string instead of no match. This was specific to
847        the use of ".".
849    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
850        complete match instead of a partial match. This bug was dependent on both
851        the PCRE_UTF8 and PCRE_DOTALL options being set.
853    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
854        starting byte set, because \b was not being ignored.
857    Version 8.12 15-Jan-2011
858    ------------------------
860    1.  Fixed some typos in the markup of the man pages, and wrote a script that
861        checks for such things as part of the documentation building process.
863    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
864        --match-limit and --recursion-limit options (added for 8.11). In
865        particular, this made one of the standard tests fail. (The integer value
866        went into the wrong half of a long int.)
868    3.  If the --colour option was given to pcregrep with -v (invert match), it
869        did strange things, either producing crazy output, or crashing. It should,
870        of course, ignore a request for colour when reporting lines that do not
871        match.
873    4.  Another pcregrep bug caused similar problems if --colour was specified with
874        -M (multiline) and the pattern match finished with a line ending.
876    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
877        matched in multiline mode, the following line was shown as part of the
878        match. This seems wrong, so I have changed it.
880    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
881        the check for further matches in the same line (so they could be coloured)
882        to overrun the end of the current line. If another match was found, it was
883        incorrectly shown (and then shown again when found in the next line).
885    7.  If pcregrep was compiled under Windows, there was a reference to the
886        function pcregrep_exit() before it was defined. I am assuming this was
887        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
888        reported by a user. I've moved the definition above the reference.
891    Version 8.11 10-Dec-2010
892    ------------------------
894    1.  (*THEN) was not working properly if there were untried alternatives prior
895        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
896        backtracked to try for "b" instead of moving to the next alternative branch
897        at the same level (in this case, to look for "c"). The Perl documentation
898        is clear that when (*THEN) is backtracked onto, it goes to the "next
899        alternative in the innermost enclosing group".
901    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
902        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
903        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
904        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
905        (*THEN).
907    3.  If \s appeared in a character class, it removed the VT character from
908        the class, even if it had been included by some previous item, for example
909        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
910        of \s, but is part of the POSIX "space" class.)
912    4.  A partial match never returns an empty string (because you can always
913        match an empty string at the end of the subject); however the checking for
914        an empty string was starting at the "start of match" point. This has been
915        changed to the "earliest inspected character" point, because the returned
916        data for a partial match starts at this character. This means that, for
917        example, /(?<=abc)def/ gives a partial match for the subject "abc"
918        (previously it gave "no match").
920    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
921        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
922        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
923        has an implication that the given string is incomplete (because a partial
924        match is preferred over a full match). For this reason, these items now
925        give a partial match in this situation. [Aside: previously, the one case
926        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
927        match rather than a full match, which was wrong by the old rules, but is
928        now correct.]
930    6.  There was a bug in the handling of #-introduced comments, recognized when
931        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
932        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
933        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
934        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
935        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
936        places in pcre_compile().
938    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
939        comments when looking ahead for named forward references to subpatterns,
940        the only newline sequence it recognized was NL. It now handles newlines
941        according to the set newline convention.
943    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
944        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
945        cater for a lack of strerror(). These oversights have been fixed.
947    9.  Added --match-limit and --recursion-limit to pcregrep.
949    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
951    11. When the -o option was used, pcregrep was setting a return code of 1, even
952        when matches were found, and --line-buffered was not being honoured.
954    12. Added an optional parentheses number to the -o and --only-matching options
955        of pcregrep.
957    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
958        can match an empty string. The code to do it in pcretest and pcredemo
959        needed fixing:
961        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
962            only one byte after an empty string match just before CRLF (this case
963            just got forgotten; "any" and "anycrlf" were OK).
965        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
966            mode when an empty string match preceded an ASCII character followed by
967            a non-ASCII character. (The code for advancing by one character rather
968            than one byte was nonsense.)
970        (c) The pcredemo.c sample program did not have any code at all to handle
971            the cases when CRLF is a valid newline sequence.
973    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
974        as a starting offset was within the subject string. There is now a new
975        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
976        negative or greater than the length of the string. In order to test this,
977        pcretest is extended to allow the setting of negative starting offsets.
979    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
980        starting offset points to the beginning of a UTF-8 character was
981        unnecessarily clumsy. I tidied it up.
983    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
984        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
986    17. Nobody had reported that the --include_dir option, which was added in
987        release 7.7 should have been called --include-dir (hyphen, not underscore)
988        for compatibility with GNU grep. I have changed it to --include-dir, but
989        left --include_dir as an undocumented synonym, and the same for
990        --exclude-dir, though that is not available in GNU grep, at least as of
991        release 2.5.4.
993    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
994        characters from a string of bytes) have been redefined so as not to use
995        loops, in order to improve performance in some environments. At the same
996        time, I abstracted some of the common code into auxiliary macros to save
997        repetition (this should not affect the compiled code).
999    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1000        compile-time error is now given if \c is not followed by an ASCII
1001        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1002        different, and any byte value is allowed.)
1004    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1005        START_OPTIMIZE option, which is now allowed at compile time - but just
1006        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1007        to pcregrep and other applications that have no direct access to PCRE
1008        options. The new /Y option in pcretest sets this option when calling
1009        pcre_compile().
1011    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1012        back references. Groups containing recursive back references were forced to
1013        be atomic by that change, but in the case of named groups, the amount of
1014        memory required was incorrectly computed, leading to "Failed: internal
1015        error: code overflow". This has been fixed.
1017    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1018        pcretest.c, to avoid build problems in some Borland environments.
1021    Version 8.10 25-Jun-2010
1022    ------------------------
1024    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1025        THEN.
1027    2.  (*ACCEPT) was not working when inside an atomic group.
1029    3.  Inside a character class, \B is treated as a literal by default, but
1030        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1031        causes the error). The code is unchanged, but I tidied the documentation.
1033    4.  Inside a character class, PCRE always treated \R and \X as literals,
1034        whereas Perl faults them if its -w option is set. I have changed PCRE so
1035        that it faults them when PCRE_EXTRA is set.
1037    5.  Added support for \N, which always matches any character other than
1038        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1040    6.  When compiling pcregrep with newer versions of gcc which may have
1041        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1042        declared with attribute warn_unused_result" were given. Just casting the
1043        result to (void) does not stop the warnings; a more elaborate fudge is
1044        needed. I've used a macro to implement this.
1046    7.  Minor change to pcretest.c to avoid a compiler warning.
1048    8.  Added four artifical Unicode properties to help with an option to make
1049        \s etc use properties (see next item). The new properties are: Xan
1050        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1052    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1053        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1054        this option. Modified pcretest to add /W to test this facility. Added
1055        REG_UCP to make it available via the POSIX interface.
1057    10. Added --line-buffered to pcregrep.
1059    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1060        studied, and the match started with a letter with a code point greater than
1061        127 whose first byte was different to the first byte of the other case of
1062        the letter, the other case of this starting letter was not recognized
1063        (#976).
1065    12. If a pattern that was studied started with a repeated Unicode property
1066        test, for example, \p{Nd}+, there was the theoretical possibility of
1067        setting up an incorrect bitmap of starting bytes, but fortunately it could
1068        not have actually happened in practice until change 8 above was made (it
1069        added property types that matched character-matching opcodes).
1071    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1072        possible starting bytes for non-anchored patterns.
1074    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1075        \R, and also a number of cases that involve Unicode properties, both
1076        explicit and implicit when PCRE_UCP is set.
1078    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1079        input, it could crash or give wrong results if characters with values
1080        greater than 0xc0 were present in the subject string. (Detail: it assumed
1081        UTF-8 input when processing these items.)
1083    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1084        size_t is 64-bit (#991).
1086    17. Added a check for running out of memory when PCRE is compiled with
1087        --disable-stack-for-recursion (#990).
1089    18. If the last data line in a file for pcretest does not have a newline on
1090        the end, a newline was missing in the output.
1092    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1093        less than 128) in its various bitmaps. However, there is a facility for
1094        generating tables according to the current locale when PCRE is compiled. It
1095        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1096        characters, are recognized by isspace() and therefore were getting set in
1097        these tables, and indeed these tables seem to approximate to ISO 8859. This
1098        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1099        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1100        which of course cannot start UTF-8 characters. I have changed the code so
1101        that only real ASCII characters (less than 128) and the correct starting
1102        bytes for UTF-8 encodings are set for characters greater than 127 when in
1103        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1104        altogether.)
1106    20. Added the /T option to pcretest so as to be able to run tests with non-
1107        standard character tables, thus making it possible to include the tests
1108        used for 19 above in the standard set of tests.
1110    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1111        reference to a subpattern the other side of a comment that contains an
1112        opening parenthesis caused either an internal compiling error, or a
1113        reference to the wrong subpattern.
1116    Version 8.02 19-Mar-2010
1117    ------------------------
1119    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1121    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1122        configured.
1124    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1125        original author of that file, following a query about its status.
1127    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1128        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1130    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1131        quantifier applied to a forward-referencing subroutine call, could compile
1132        incorrect code or give the error "internal error: previously-checked
1133        referenced subpattern not found".
1135    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1136        variables to point to external functions. For these systems, therefore,
1137        pcre_malloc etc. are now initialized to local functions that call the
1138        relevant global functions.
1140    7.  There were two entries missing in the vectors called coptable and poptable
1141        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1142        I've fixed the data, and added a kludgy way of testing at compile time that
1143        the lengths are correct (equal to the number of opcodes).
1145    8.  Following on from 7, I added a similar kludge to check the length of the
1146        eint vector in pcreposix.c.
1148    9.  Error texts for pcre_compile() are held as one long string to avoid too
1149        much relocation at load time. To find a text, the string is searched,
1150        counting zeros. There was no check for running off the end of the string,
1151        which could happen if a new error number was added without updating the
1152        string.
1154    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1156    11. \K was not working if it appeared in an atomic group or in a group that
1157        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1158        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1159        the assertion is positive, but not if it is negative.
1161    12. Change 11 fortuitously reduced the size of the stack frame used in the
1162        "match()" function of pcre_exec.c by one pointer. Forthcoming
1163        implementation of support for (*MARK) will need an extra pointer on the
1164        stack; I have reserved it now, so that the stack frame size does not
1165        decrease.
1167    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1168        item in branch that calls a recursion is a subroutine call - as in the
1169        second branch in the above example - was incorrectly given the compile-
1170        time error "recursive call could loop indefinitely" because pcre_compile()
1171        was not correctly checking the subroutine for matching a non-empty string.
1173    14. The checks for overrunning compiling workspace could trigger after an
1174        overrun had occurred. This is a "should never occur" error, but it can be
1175        triggered by pathological patterns such as hundreds of nested parentheses.
1176        The checks now trigger 100 bytes before the end of the workspace.
1178    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1181    Version 8.01 19-Jan-2010
1182    ------------------------
1184    1.  If a pattern contained a conditional subpattern with only one branch (in
1185        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1186        computed the wrong minimum data length (which is of course zero for such
1187        subpatterns). This could cause incorrect "no match" results.
1189    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1190        the pattern is reset in the first branch, pcre_compile() failed with
1191        "internal error: code overflow at offset...". This happened only when
1192        the reset was to the original external option setting. (An optimization
1193        abstracts leading options settings into an external setting, which was the
1194        cause of this.)
1196    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1197        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1198        assertion pattern did not match (meaning that the assertion was true), it
1199        was incorrectly treated as false if the SKIP had been reached during the
1200        matching. This also applied to assertions used as conditions.
1202    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1203        assertion subpattern, including such a pattern used as a condition,
1204        unpredictable results occurred, instead of the error return
1207    5.  The C++ GlobalReplace function was not working like Perl for the special
1208        situation when an empty string is matched. It now does the fancy magic
1209        stuff that is necessary.
1211    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1212        removed. (These were left over from very, very early versions of PCRE.)
1214    7.  Some cosmetic changes to the code to make life easier when compiling it
1215        as part of something else:
1217        (a) Change DEBUG to PCRE_DEBUG.
1219        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1220            called "current" as "current_branch", to prevent a collision with the
1221            Linux macro when compiled as a kernel module.
1223        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1224            prevent a collision with the Linux macro when compiled as a kernel
1225            module.
1227    8.  In pcre_compile() there are some checks for integer overflows that used to
1228        cast potentially large values to (double). This has been changed to that
1229        when building, a check for int64_t is made, and if it is found, it is used
1230        instead, thus avoiding the use of floating point arithmetic. (There is no
1231        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1232        double.
1234    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1235        2005 (difference between two addresses compared to an unsigned value).
1237    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1238        custom one, because of the following reported problem in Windows:
1240          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1241              under Win32.
1242          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1243              therefore missing the function definition.
1244          - The compiler thus generates a "C" signature for the test function.
1245          - The linker fails to find the "C" function.
1246          - PCRE fails to configure if asked to do so against libbz2.
1248    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1249        messages were output:
1251          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1252          rerunning libtoolize, to keep the correct libtool macros in-tree.
1253          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1255        I have done both of these things.
1257    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1258        most of the time, it *can* run out if it is given a pattern that contains a
1259        runaway infinite recursion. I updated the discussion in the pcrestack man
1260        page.
1262    13. Now that we have gone to the x.xx style of version numbers, the minor
1263        version may start with zero. Using 08 or 09 is a bad idea because users
1264        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1265        interpreted as invalid octal numbers. I've updated the previous comment in
1266        configure.ac, and also added a check that gives an error if 08 or 09 are
1267        used.
1269    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1270        causing partial matching to fail when the end of the subject matched \W
1271        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1273    15. There were some discrepancies between the declarations in pcre_internal.h
1274        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1275        their definitions. The declarations used "const uschar *" and the
1276        definitions used USPTR. Even though USPTR is normally defined as "const
1277        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1278        reported that: "This difference in casting confuses some C++ compilers, for
1279        example, SunCC recognizes above declarations as different functions and
1280        generates broken code for hbpcre." I have changed the declarations to use
1281        USPTR.
1283    16. GNU libtool is named differently on some systems. The autogen.sh script now
1284        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1285        (FreeBSD).
1287    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1288        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1289        comment: "Figure out how to create a longlong from a string: strtoll and
1290        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1291        instance, but it only takes 2 args instead of 3!"
1293    18. A subtle bug concerned with back references has been fixed by a change of
1294        specification, with a corresponding code fix. A pattern such as
1295        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1296        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1297        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1298        same bug. Such groups have to be quantified to be useful, or contained
1299        inside another quantified group. (If there's no repetition, the reference
1300        can never match.) The problem arises because, having left the group and
1301        moved on to the rest of the pattern, a later failure that backtracks into
1302        the group uses the captured value from the final iteration of the group
1303        rather than the correct earlier one. I have fixed this in PCRE by forcing
1304        any group that contains a reference to itself to be an atomic group; that
1305        is, there cannot be any backtracking into it once it has completed. This is
1306        similar to recursive and subroutine calls.
1309    Version 8.00 19-Oct-09
1310    ----------------------
1312    1.  The table for translating pcre_compile() error codes into POSIX error codes
1313        was out-of-date, and there was no check on the pcre_compile() error code
1314        being within the table. This could lead to an OK return being given in
1315        error.
1317    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1318        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1319        in a Windows environment.
1321    3.  The pcregrep --count option prints the count for each file even when it is
1322        zero, as does GNU grep. However, pcregrep was also printing all files when
1323        --files-with-matches was added. Now, when both options are given, it prints
1324        counts only for those files that have at least one match. (GNU grep just
1325        prints the file name in this circumstance, but including the count seems
1326        more useful - otherwise, why use --count?) Also ensured that the
1327        combination -clh just lists non-zero counts, with no names.
1329    4.  The long form of the pcregrep -F option was incorrectly implemented as
1330        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1331        but it seems right to fix it, and I didn't think it was worth preserving
1332        the old behaviour.
1334    5.  The command line items --regex=pattern and --regexp=pattern were not
1335        recognized by pcregrep, which required --regex pattern or --regexp pattern
1336        (with a space rather than an '='). The man page documented the '=' forms,
1337        which are compatible with GNU grep; these now work.
1339    6.  No libpcreposix.pc file was created for pkg-config; there was just
1340        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1342    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1343        when UCP support is not needed, by modifying the Python script that
1344        generates it from Unicode data files. This should not matter if the module
1345        is correctly used as a library, but I received one complaint about 50K of
1346        unwanted data. My guess is that the person linked everything into his
1347        program rather than using a library. Anyway, it does no harm.
1349    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1350        was a minimum greater than 1 for a wide character in a possessive
1351        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1352        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1353        character. Chaos in the form of incorrect output or a compiling loop could
1354        result.
1356    9.  The restrictions on what a pattern can contain when partial matching is
1357        requested for pcre_exec() have been removed. All patterns can now be
1358        partially matched by this function. In addition, if there are at least two
1359        slots in the offset vector, the offset of the earliest inspected character
1360        for the match and the offset of the end of the subject are set in them when
1361        PCRE_ERROR_PARTIAL is returned.
1363    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1364        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1365        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1366        and may be more useful for multi-segment matching.
1368    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1369        used to be given if ever the end of the subject was reached; now it is
1370        given only if matching could not proceed because another character was
1371        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1372        string "Z", which now yields "no match" instead of "partial match". In the
1373        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1374        final character ended with (*FAIL).
1376    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1377        if the pattern had a "must contain" character that was already found in the
1378        earlier partial match, unless partial matching was again requested. For
1379        example, with the pattern /dog.(body)?/, the "must contain" character is
1380        "g". If the first part-match was for the string "dog", restarting with
1381        "sbody" failed. This bug has been fixed.
1383    13. The string returned by pcre_dfa_exec() after a partial match has been
1384        changed so that it starts at the first inspected character rather than the
1385        first character of the match. This makes a difference only if the pattern
1386        starts with a lookbehind assertion or \b or \B (\K is not supported by
1387        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1388        matching functions compatible, and I think it's the right thing to do.
1390    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1391        so that the demonstration program is easily available in environments where
1392        PCRE has not been installed from source.
1394    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1395        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1396        library.
1398    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1399        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1400        is not the first non-POSIX option to be added. Clearly some people find
1401        these options useful.
1403    17. If a caller to the POSIX matching function regexec() passes a non-zero
1404        value for nmatch with a NULL value for pmatch, the value of
1405        nmatch is forced to zero.
1407    18. RunGrepTest did not have a test for the availability of the -u option of
1408        the diff command, as RunTest does. It now checks in the same way as
1409        RunTest, and also checks for the -b option.
1411    19. If an odd number of negated classes containing just a single character
1412        interposed, within parentheses, between a forward reference to a named
1413        subpattern and the definition of the subpattern, compilation crashed with
1414        an internal error, complaining that it could not find the referenced
1415        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1416        [The bug was that it was starting one character too far in when skipping
1417        over the character class, thus treating the ] as data rather than
1418        terminating the class. This meant it could skip too much.]
1420    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1421        /g option in pcretest when the pattern contains \K, which makes it possible
1422        to have an empty string match not at the start, even when the pattern is
1423        anchored. Updated pcretest and pcredemo to use this option.
1425    21. If the maximum number of capturing subpatterns in a recursion was greater
1426        than the maximum at the outer level, the higher number was returned, but
1427        with unset values at the outer level. The correct (outer level) value is
1428        now given.
1430    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1431        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1432        make it do so. The string so far is captured, making this feature
1433        compatible with Perl.
1435    23. The tests have been re-organized, adding tests 11 and 12, to make it
1436        possible to check the Perl 5.10 features against Perl 5.10.
1438    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1439        pattern matches a fixed length string. PCRE did not allow this; now it
1440        does. Neither allows recursion.
1442    25. I finally figured out how to implement a request to provide the minimum
1443        length of subject string that was needed in order to match a given pattern.
1444        (It was back references and recursion that I had previously got hung up
1445        on.) This code has now been added to pcre_study(); it finds a lower bound
1446        to the length of subject needed. It is not necessarily the greatest lower
1447        bound, but using it to avoid searching strings that are too short does give
1448        some useful speed-ups. The value is available to calling programs via
1449        pcre_fullinfo().
1451    26. While implementing 25, I discovered to my embarrassment that pcretest had
1452        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1453        study optimizations had never been tested with that matching function.
1454        Oops. What is worse, even when it was passed study data, there was a bug in
1455        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1456        were also very few tests of studied patterns with pcre_dfa_exec().
1458    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1459        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1460        on the other side of the coin, they are no longer allowed to have different
1461        names, because these cannot be distinguished in PCRE, and this has caused
1462        confusion. (This is a difference from Perl.)
1464    28. When duplicate subpattern names are present (necessarily with different
1465        numbers, as required by 27 above), and a test is made by name in a
1466        conditional pattern, either for a subpattern having been matched, or for
1467        recursion in such a pattern, all the associated numbered subpatterns are
1468        tested, and the overall condition is true if the condition is true for any
1469        one of them. This is the way Perl works, and is also more like the way
1470        testing by number works.
1473    Version 7.9 11-Apr-09
1474    ---------------------
1476    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1477        (pcretest), all targets were linked against these libraries. This included
1478        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1479        libraries. This caused unwanted dependencies to be created. This problem
1480        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1481        pcretest is linked with readline.
1483    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1484        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1485        moved outside it again, because FALSE and TRUE are already defined in AIX,
1486        but BOOL is not.
1488    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1489        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1491    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1492        hyphens) following file names and line numbers when outputting matching
1493        lines. This is not true; no spaces are inserted. I have also clarified the
1494        wording for the --colour (or --color) option.
1496    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1497        was not coloured; this is different to GNU grep, so I have changed it to be
1498        the same.
1500    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1501        each matching line was coloured. Now it goes on to look for further matches
1502        of any of the test patterns, which is the same behaviour as GNU grep.
1504    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1505        doesn't make sense to accept an empty string match in pcregrep, so I have
1506        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1507        seems to be how GNU grep behaves.
1509    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1510        start or after a newline", because the conditional assertion was not being
1511        correctly handled. The rule now is that both the assertion and what follows
1512        in the first alternative must satisfy the test.
1514    9.  If auto-callout was enabled in a pattern with a conditional group whose
1515        condition was an assertion, PCRE could crash during matching, both with
1516        pcre_exec() and pcre_dfa_exec().
1518    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1519        used for matching.
1521    11. Unicode property support in character classes was not working for
1522        characters (bytes) greater than 127 when not in UTF-8 mode.
1524    12. Added the -M command line option to pcretest.
1526    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1528    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1530    16. Added comments and documentation about mis-use of no_arg in the C++
1531        wrapper.
1533    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1534        from Martin Jerabek that uses macro names for all relevant character and
1535        string constants.
1537    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1538        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1539        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1540        these, but not everybody uses configure.
1542    19. A conditional group that had only one branch was not being correctly
1543        recognized as an item that could match an empty string. This meant that an
1544        enclosing group might also not be so recognized, causing infinite looping
1545        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1546        with the subject "ab", where knowledge that the repeated group can match
1547        nothing is needed in order to break the loop.
1549    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1550        exec(), but without supplying a callout function, matching went wrong.
1552    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1553        leak if the size of the offset vector was greater than 30. When the vector
1554        is smaller, the saved offsets during recursion go onto a local stack
1555        vector, but for larger vectors malloc() is used. It was failing to free
1556        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1557        error, in fact).
1559    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1560        heapframe that is used only when UTF-8 support is enabled. This caused no
1561        problem, but was untidy.
1563    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1564        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1565        included within another project.
1567    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1568        slightly modified by me:
1570          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1571              not building pcregrep.
1573          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1574              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1576    25. Forward references, both numeric and by name, in patterns that made use of
1577        duplicate group numbers, could behave incorrectly or give incorrect errors,
1578        because when scanning forward to find the reference group, PCRE was not
1579        taking into account the duplicate group numbers. A pattern such as
1580        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1582    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1583        the feature of a custom pointer more persuasive (as requested by a user).
1585    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1586        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1587        pre-defined.
1589    28. Added support for (*UTF8) at the start of a pattern.
1591    29. Arrange for flags added by the "release type" setting in CMake to be shown
1592        in the configuration summary.
1595    Version 7.8 05-Sep-08
1596    ---------------------
1598    1.  Replaced UCP searching code with optimized version as implemented for Ad
1599        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1600        stage table and inline lookup instead of a function, giving speed ups of 2
1601        to 5 times on some simple patterns that I tested. Permission was given to
1602        distribute the MultiStage2.py script that generates the tables (it's not in
1603        the tarball, but is in the Subversion repository).
1605    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1606        scripts.
1608    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1609        a group with a zero qualifier. The result of the study could be incorrect,
1610        or the function might crash, depending on the pattern.
1612    4.  Caseless matching was not working for non-ASCII characters in back
1613        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1614        It now works when Unicode Property Support is available.
1616    5.  In pcretest, an escape such as \x{de} in the data was always generating
1617        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1618        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1619        truncation.
1621    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1623    7.  Added two (int) casts to pcregrep when printing the difference of two
1624        pointers, in case they are 64-bit values.
1626    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1627        test 2 if it fails.
1629    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1630        and a #define of that name to empty if it is not externally set. This is to
1631        allow users of MSVC to set it if necessary.
1633    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1634        the convenience functions in the pcre_get.c source file.
1636    11. An option change at the start of a pattern that had top-level alternatives
1637        could cause overwriting and/or a crash. This command provoked a crash in
1638        some environments:
1640          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1642        This potential security problem was recorded as CVE-2008-2371.
1644    12. For a pattern where the match had to start at the beginning or immediately
1645        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1646        pcre_dfa_exec() could read past the end of the passed subject if there was
1647        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1648        pcretest so that it places the subject at the end of its malloc-ed buffer.
1650    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1651        exec() might read past the end of the data buffer in UTF-8 mode.
1653    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1654        the data contained the byte 0x85 as part of a UTF-8 character within its
1655        first line. This applied both to normal and DFA matching.
1657    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1658        /^[^d]*?$/8 failed to match "abc".
1660    16. Added a missing copyright notice to pcrecpp_internal.h.
1662    17. Make it more clear in the documentation that values returned from
1663        pcre_exec() in ovector are byte offsets, not character counts.
1665    18. Tidied a few places to stop certain compilers from issuing warnings.
1667    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1668        supplied by Stefan Weber. I made a further small update for 7.8 because
1669        there is a change of source arrangements: the pcre_searchfuncs.c module is
1670        replaced by pcre_ucd.c.
1673    Version 7.7 07-May-08
1674    ---------------------
1676    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1677        a string to a long long, pretend we don't even have a long long." This is
1678        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1680    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1681        pre-7.6 versions, which defined a global no_arg variable instead of putting
1682        it in the RE class. (See also #8 below.)
1684    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1685        Lopes.
1687    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1689        (1) The include/exclude patterns were being applied to the whole pathnames
1690            of files, instead of just to the final components.
1692        (2) If there was more than one level of directory, the subdirectories were
1693            skipped unless they satisfied the include/exclude conditions. This is
1694            inconsistent with GNU grep (and could even be seen as contrary to the
1695            pcregrep specification - which I improved to make it absolutely clear).
1696            The action now is always to scan all levels of directory, and just
1697            apply the include/exclude patterns to regular files.
1699    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1700        --exclude_dir in the tests to avoid scanning .svn directories.
1702    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1703        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1704        doesn't support NULs in patterns.
1706    7.  Added some missing "const"s to declarations of static tables in
1707        pcre_compile.c and pcre_dfa_exec.c.
1709    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1710        caused by fix #2  above. (Subsequently also a second patch to fix the
1711        first patch. And a third patch - this was a messy problem.)
1713    9.  Applied Craig's patch to remove the use of push_back().
1715    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1716        matching function regexec().
1718    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1719        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1720        references. PCRE supports relative numbers with this syntax (I don't think
1721        Oniguruma does).
1723    12. Previously, a group with a zero repeat such as (...){0} was completely
1724        omitted from the compiled regex. However, this means that if the group
1725        was called as a subroutine from elsewhere in the pattern, things went wrong
1726        (an internal error was given). Such groups are now left in the compiled
1727        pattern, with a new opcode that causes them to be skipped at execution
1728        time.
1730    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1731        to the way PCRE behaves:
1733        (a) A lone ] character is dis-allowed (Perl treats it as data).
1735        (b) A back reference to an unmatched subpattern matches an empty string
1736            (Perl fails the current match path).
1738        (c) A data ] in a character class must be notated as \] because if the
1739            first data character in a class is ], it defines an empty class. (In
1740            Perl it is not possible to have an empty class.) The empty class []
1741            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1742            The negative empty class [^] matches any one character, independently
1743            of the DOTALL setting.
1745    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1746        non-existent subpattern following a character class starting with ']' and
1747        containing () gave an internal compiling error instead of "reference to
1748        non-existent subpattern". Fortunately, when the pattern did exist, the
1749        compiled code was correct. (When scanning forwards to check for the
1750        existencd of the subpattern, it was treating the data ']' as terminating
1751        the class, so got the count wrong. When actually compiling, the reference
1752        was subsequently set up correctly.)
1754    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1755        it was being rejected as not supported by pcre_dfa_exec(), even though
1756        other assertions are supported. I have made pcre_dfa_exec() support
1757        (*FAIL).
1759    16. The implementation of 13c above involved the invention of a new opcode,
1760        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1761        cannot be changed at match time, I realized I could make a small
1762        improvement to matching performance by compiling OP_ALLANY instead of
1763        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1764        on the OP_ANY path.
1766    17. Compiling pcretest on Windows with readline support failed without the
1767        following two fixes: (1) Make the unistd.h include conditional on
1768        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1770    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1771        ncurses library to be included for pcretest when ReadLine support is
1772        requested, but also to allow for it to be overridden. This patch came from
1773        Daniel Bergström.
1775    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1776        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1777        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1778        spotting this.
1781    Version 7.6 28-Jan-08
1782    ---------------------
1784    1.  A character class containing a very large number of characters with
1785        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1786        overflow.
1788    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1789        HAVE_LONG_LONG is not defined.
1791    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1792        bring them up to date and include new features. This patch includes:
1794        - Fixed PH's badly added libz and libbz2 support.
1795        - Fixed a problem with static linking.
1796        - Added pcredemo. [But later removed - see 7 below.]
1797        - Fixed dftables problem and added an option.
1798        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1799            HAVE_LONG_LONG.
1800        - Added readline support for pcretest.
1801        - Added an listing of the option settings after cmake has run.
1803    4.  A user submitted a patch to Makefile that makes it easy to create
1804        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1805        Makefile.am that cause it to include this special target, without
1806        affecting anything else. Note that the same mingw target plus all
1807        the other distribution libraries and programs are now supported
1808        when configuring with CMake (see 6 below) instead of with
1809        Configure/Make.
1811    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1812        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1813        exported in the Windows port". It has not yet been confirmed that the patch
1814        solves the problem, but it does no harm.
1816    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1817        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1818        with CMake, and also correct the comment about stack recursion.
1820    7.  Remove the automatic building of pcredemo from the ./configure system and
1821        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1822        of a program that users should build themselves after PCRE is installed, so
1823        building it automatically is not really right. What is more, it gave
1824        trouble in some build environments.
1826    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1829    Version 7.5 10-Jan-08
1830    ---------------------
1832    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1833        values in parens when parsing an RE using the C++ wrapper."
1835    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1836        Characters greater than 255 were excluded from the class instead of being
1837        included.
1839    3.  The same bug as (2) above applied to negated POSIX classes such as
1840        [:^space:].
1842    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1843        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1844        I have changed it.
1846    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1847        first named subpattern) and a construct such as (?&a) would reference the
1848        first named subpattern whose name started with "a" (in other words, the
1849        length check was missing). Both these problems are fixed. "Subpattern name
1850        expected" is now given for (?&) (a zero-length name), and this patch also
1851        makes it give the same error for \k'' (previously it complained that that
1852        was a reference to a non-existent subpattern).
1854    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1855        this is right because (?- can be followed by option settings as well as by
1856        digits. I have, however, made the messages clearer.
1858    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1859        than the number used in the conditional) now cause a compile-time error.
1860        This is actually not compatible with Perl, which accepts such patterns, but
1861        treats the conditional as always being FALSE (as PCRE used to), but it
1862        seems to me that giving a diagnostic is better.
1864    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1865        and messages.
1867    9.  Fix two occurrences of "backslash" in comments that should have been
1868        "backspace".
1870    10. Remove two redundant lines of code that can never be obeyed (their function
1871        was moved elsewhere).
1873    11. The program that makes PCRE's Unicode character property table had a bug
1874        which caused it to generate incorrect table entries for sequences of
1875        characters that have the same character type, but are in different scripts.
1876        It amalgamated them into a single range, with the script of the first of
1877        them. In other words, some characters were in the wrong script. There were
1878        thirteen such cases, affecting characters in the following ranges:
1880          U+002b0 - U+002c1
1881          U+0060c - U+0060d
1882          U+0061e - U+00612
1883          U+0064b - U+0065e
1884          U+0074d - U+0076d
1885          U+01800 - U+01805
1886          U+01d00 - U+01d77
1887          U+01d9b - U+01dbf
1888          U+0200b - U+0200f
1889          U+030fc - U+030fe
1890          U+03260 - U+0327f
1891          U+0fb46 - U+0fbb1
1892          U+10450 - U+1049d
1894    12. The -o option (show only the matching part of a line) for pcregrep was not
1895        compatible with GNU grep in that, if there was more than one match in a
1896        line, it showed only the first of them. It now behaves in the same way as
1897        GNU grep.
1899    13. If the -o and -v options were combined for pcregrep, it printed a blank
1900        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1901        does the same. The return code can be used to tell if there were any
1902        non-matching lines.
1904    14. Added --file-offsets and --line-offsets to pcregrep.
1906    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1907        infinitely looping recursion. The bug was that positive lookaheads were not
1908        being skipped when checking for a possible empty match (negative lookaheads
1909        and both kinds of lookbehind were skipped).
1911    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1912        inclusion of <windows.h> to before rather than after the definition of
1913        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1915    17. Specifying a possessive quantifier with a specific limit for a Unicode
1916        character property caused pcre_compile() to compile bad code, which led at
1917        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1918        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1919        caused the error; without that there was no problem.
1921    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1923    19. Added --enable-pcretest-libreadline.
1925    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1926        RE::GlobalReplace(). As a result, the number of replacements returned was
1927        double what it should be. I removed one of the increments, but Craig sent a
1928        later patch that removed the other one (the right fix) and added unit tests
1929        that check the return values (which was not done before).
1931    21. Several CMake things:
1933        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1934            the names libpcre and libpcreposix, not just pcre and pcreposix.
1936        (2) The above change means that pcretest and pcregrep are now correctly
1937            linked with the newly-built libraries, not previously installed ones.
1941    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1942        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1943        UTF-8 newline character). The key issue is that the pattern starts .*;
1944        this means that the match must be either at the beginning, or after a
1945        newline. The bug was in the code for advancing after a failed match and
1946        checking that the new position followed a newline. It was not taking
1947        account of UTF-8 characters correctly.
1949    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1950        character classes. PCRE was not treating the sequence [:...:] as a
1951        character class unless the ... were all letters. Perl, however, seems to
1952        allow any characters between [: and :], though of course it rejects as
1953        unknown any "names" that contain non-letters, because all the known class
1954        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1955        for example, whereas PCRE did not - it did not recognize a POSIX character
1956        class. This seemed a bit dangerous, so the code has been changed to be
1957        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1958        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1959        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1960        Perl does, and where it didn't before.
1962    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1963        Windows environments %n is disabled by default.
1966    Version 7.4 21-Sep-07
1967    ---------------------
1969    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1970        means that a class such as [\s] counted as "explicit reference to CR or
1971        LF". That isn't really right - the whole point of the change was to try to
1972        help when there was an actual mention of one of the two characters. So now
1973        the change happens only if \r or \n (or a literal CR or LF) character is
1974        encountered.
1976    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1977        of both had grown to the point where there were only 3 bits left.
1978        Fortunately, there was spare space in the data structure, and so I have
1979        moved the internal flags into a new 16-bit field to free up more option
1980        bits.
1982    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1983        but did not set the internal JCHANGED flag - either of these is enough to
1984        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1985        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1986        start sets both bits.
1988    4.  Added options (at build time, compile time, exec time) to change \R from
1989        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1991    5.  doc/pcresyntax.html was missing from the distribution.
1993    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1994        compatibility, even though it is no longer used.
1996    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1997        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1998        windows.h file is present (where different names are used). [This was
1999        reversed later after testing - see 16 below.]
2001    8.  Changed all #include <config.h> to #include "config.h". There were also
2002        some further <pcre.h> cases that I changed to "pcre.h".
2004    9.  When pcregrep was used with the --colour option, it missed the line ending
2005        sequence off the lines that it output.
2007    10. It was pointed out to me that arrays of string pointers cause lots of
2008        relocations when a shared library is dynamically loaded. A technique of
2009        using a single long string with a table of offsets can drastically reduce
2010        these. I have refactored PCRE in four places to do this. The result is
2011        dramatic:
2013          Originally:                          290
2014          After changing UCP table:            187
2015          After changing error message table:   43
2016          After changing table of "verbs"       36
2017          After changing table of Posix names   22
2019        Thanks to the folks working on Gregex for glib for this insight.
2021    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2022        unicode-properties was also set.
2024    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2026    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2027        checked only for CRLF.
2029    14. Added casts to pcretest.c to avoid compiler warnings.
2031    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2033    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2034        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2035        entirely. This removes changes made in 7 above.
2037    17. The CMake files have been updated, and there is now more information about
2038        building with CMake in the NON-UNIX-USE document.
2041    Version 7.3 28-Aug-07
2042    ---------------------
2044     1. In the rejigging of the build system that eventually resulted in 7.1, the
2045        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2046        brackets there is not right, since it causes compilers to look for an
2047        installed pcre.h, not the version that is in the source that is being
2048        compiled (which of course may be different). I have changed it back to:
2050          #include "pcre.h"
2052        I have a vague recollection that the change was concerned with compiling in
2053        different directories, but in the new build system, that is taken care of
2054        by the VPATH setting the Makefile.
2056     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2057        when the subject happened to end in the byte 0x85 (e.g. if the last
2058        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2059        characters but of course it shouldn't be taken as a newline when it is part
2060        of another character. The bug was that, for an unlimited repeat of . in
2061        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2062        characters when looking for a newline.
2064     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2066     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2067        in debug output.
2069     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2070        long printing in the pcrecpp unittest when running under MinGW.
2072     6. ESC_K was left out of the EBCDIC table.
2074     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2075        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2076        limit also applies to "virtual nesting" when a pattern is recursive, and in
2077        this case 1000 isn't so big. I have been able to remove this limit at the
2078        expense of backing off one optimization in certain circumstances. Normally,
2079        when pcre_exec() would call its internal match() function recursively and
2080        immediately return the result unconditionally, it uses a "tail recursion"
2081        feature to save stack. However, when a subpattern that can match an empty
2082        string has an unlimited repetition quantifier, it no longer makes this
2083        optimization. That gives it a stack frame in which to save the data for
2084        checking that an empty string has been matched. Previously this was taken
2085        from the 1000-entry workspace that had been reserved. So now there is no
2086        explicit limit, but more stack is used.
2088     8. Applied Daniel's patches to solve problems with the import/export magic
2089        syntax that is required for Windows, and which was going wrong for the
2090        pcreposix and pcrecpp parts of the library. These were overlooked when this
2091        problem was solved for the main library.
2093     9. There were some crude static tests to avoid integer overflow when computing
2094        the size of patterns that contain repeated groups with explicit upper
2095        limits. As the maximum quantifier is 65535, the maximum group length was
2096        set at 30,000 so that the product of these two numbers did not overflow a
2097        32-bit integer. However, it turns out that people want to use groups that
2098        are longer than 30,000 bytes (though not repeat them that many times).
2099        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2100        made it possible to implement the integer overflow checks in a much more
2101        dynamic way, which I have now done. The artificial limitation on group
2102        length has been removed - we now have only the limit on the total length of
2103        the compiled pattern, which depends on the LINK_SIZE setting.
2105    10. Fixed a bug in the documentation for get/copy named substring when
2106        duplicate names are permitted. If none of the named substrings are set, the
2107        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2108        empty string.
2110    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2111        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2112        because the ] is interpreted as the first data character and the
2113        terminating ] is not found. PCRE has been made compatible with Perl in this
2114        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2115        cause memory overwriting.
2117    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2118        string has been matched (to stop an infinite loop). It was not recognizing
2119        a conditional subpattern that could match an empty string if that
2120        subpattern was within another subpattern. For example, it looped when
2121        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
2122        condition was not nested. This bug has been fixed.
2124    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2125        past the start of the subject in the presence of bytes with the top bit
2126        set, for example "\x8aBCD".
2128    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2129        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2131    14. Optimized (?!) to (*FAIL).
2133    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2134        This restricts code points to be within the range 0 to 0x10FFFF, excluding
2135        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2136        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2137        does: it's just the validity check that is more restrictive.
2139    16. Inserted checks for integer overflows during escape sequence (backslash)
2140        processing, and also fixed erroneous offset values for syntax errors during
2141        backslash processing.
2143    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2144        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2146    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2147        caused an overrun.
2149    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2150        something other than just ASCII characters) inside a group that had an
2151        unlimited repeat caused a loop at compile time (while checking to see
2152        whether the group could match an empty string).
2154    20. Debugging a pattern containing \p or \P could cause a crash. For example,
2155        [\P{Any}] did so. (Error in the code for printing property names.)
2157    21. An orphan \E inside a character class could cause a crash.
2159    22. A repeated capturing bracket such as (A)? could cause a wild memory
2160        reference during compilation.
2162    23. There are several functions in pcre_compile() that scan along a compiled
2163        expression for various reasons (e.g. to see if it's fixed length for look
2164        behind). There were bugs in these functions when a repeated \p or \P was
2165        present in the pattern. These operators have additional parameters compared
2166        with \d, etc, and these were not being taken into account when moving along
2167        the compiled data. Specifically:
2169        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2170            length.
2172        (b) An item such as \pL+ within a repeated group could cause crashes or
2173            loops.
2175        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2176            "reference to non-existent subpattern" error.
2178        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2180    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2181        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2183    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2185    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2186        character were causing crashes (broken optimization).
2188    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2189        \p or \P) caused a compile-time loop.
2191    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2192        break. For example, the unstudied pattern [\r\n]A does not match the string
2193        "\r\nA" because change 7.0/46 below moves the current point on by two
2194        characters after failing to match at the start. However, the pattern \nA
2195        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2196        the same is true. There doesn't seem any very clean way out of this, but
2197        what I have chosen to do makes the common cases work: PCRE now takes note
2198        of whether there can be an explicit match for \r or \n anywhere in the
2199        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2200        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2201        pattern has explicit CR or LF references.
2203    29. Added (*CR) etc for changing newline setting at start of pattern.
2206    Version 7.2 19-Jun-07
2207    ---------------------
2209     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2210        which is apparently normally available under Windows.
2212     2. Re-jig the pcregrep tests with different newline settings in an attempt
2213        to make them independent of the local environment's newline setting.
2215     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2217     4. Some of the "internals" tests were previously cut out when the link size
2218        was not 2, because the output contained actual offsets. The recent new
2219        "Z" feature of pcretest means that these can be cut out, making the tests
2220        usable with all link sizes.
2222     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2223        stack recursion. This gives a massive performance boost under BSD, but just
2224        a small improvement under Linux. However, it saves one field in the frame
2225        in all cases.
2227     6. Added more features from the forthcoming Perl 5.10:
2229        (a) (?-n) (where n is a string of digits) is a relative subroutine or
2230            recursion call. It refers to the nth most recently opened parentheses.
2232        (b) (?+n) is also a relative subroutine call; it refers to the nth next
2233            to be opened parentheses.
2235        (c) Conditions that refer to capturing parentheses can be specified
2236            relatively, for example, (?(-2)... or (?(+3)...
2238        (d) \K resets the start of the current match so that everything before
2239            is not part of it.
2241        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2243        (f) \g{name} is another synonym - part of Perl 5.10's unification of
2244            reference syntax.
2246        (g) (?| introduces a group in which the numbering of parentheses in each
2247            alternative starts with the same number.
2249        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2251     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2254     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
2255        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2256        for detecting groups that can match an empty string.
2258     9. A pattern with a very large number of alternatives (more than several
2259        hundred) was running out of internal workspace during the pre-compile
2260        phase, where pcre_compile() figures out how much memory will be needed. A
2261        bit of new cunning has reduced the workspace needed for groups with
2262        alternatives. The 1000-alternative test pattern now uses 12 bytes of
2263        workspace instead of running out of the 4096 that are available.
2265    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2267    11. Applied patch from Google to remove an optimization that didn't quite work.
2268        The report of the bug said:
2270          pcrecpp::RE("a*").FullMatch("aaa") matches, while
2271          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2272          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2274    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2275        it matched the wrong number of bytes.
2278    Version 7.1 24-Apr-07
2279  ---------------------  ---------------------
2281   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
# Line 136  Version 7.1 12-Mar-07 Line 2410  Version 7.1 12-Mar-07
2410      string at the end of a line did not allow for this case. They now check for      string at the end of a line did not allow for this case. They now check for
2411      it specially.      it specially.
2413    20. pcretest is supposed to handle patterns and data of any length, by
2414        extending its buffers when necessary. It was getting this wrong when the
2415        buffer for a data line had to be extended.
2417    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2418        CRLF as a newline sequence.
2420    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2421        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2422        I have nevertheless tidied it up.
2424    23. Added some casts to kill warnings from HP-UX ia64 compiler.
2426    24. Added a man page for pcre-config.
2429  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
2430  ---------------------  ---------------------

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