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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.5 12-Nov-07  Version 8.32
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).
76    Version 8.31 06-July-2012
77    -------------------------
79    1.  Fixing a wrong JIT test case and some compiler warnings.
81    2.  Removed a bashism from the RunTest script.
83    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
84        to unsigned type, result still unsigned" that was given by an MS compiler
85        on encountering the code "-sizeof(xxx)".
87    4.  Partial matching support is added to the JIT compiler.
89    5.  Fixed several bugs concerned with partial matching of items that consist
90        of more than one character:
92        (a) /^(..)\1/ did not partially match "aba" because checking references was
93            done on an "all or nothing" basis. This also applied to repeated
94            references.
96        (b) \R did not give a hard partial match if \r was found at the end of the
97            subject.
99        (c) \X did not give a hard partial match after matching one or more
100            characters at the end of the subject.
102        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
103            a partial match for the string "\r".
105        (e) When newline was set to CRLF, the metacharacter "." did not recognize
106            a partial match for a CR character at the end of the subject string.
108    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
109        running pcretest, the text "(JIT)" added to the output whenever JIT is
110        actually used to run the match.
112    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
113        or /S+[+] with a digit between 1 and 7.
115    8.  OP_NOT now supports any UTF character not just single-byte ones.
117    9.  (*MARK) control verb is now supported by the JIT compiler.
119    10. The command "./RunTest list" lists the available tests without actually
120        running any of them. (Because I keep forgetting what they all are.)
124    12. Applied a (slightly modified) user-supplied patch that improves performance
125        when the heap is used for recursion (compiled with --disable-stack-for-
126        recursion). Instead of malloc and free for each heap frame each time a
127        logical recursion happens, frames are retained on a chain and re-used where
128        possible. This sometimes gives as much as 30% improvement.
130    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
131        call.
133    14. As documented, (*COMMIT) is now confined to within a positive assertion.
135    15. It is now possible to link pcretest with libedit as an alternative to
136        libreadline.
138    16. (*COMMIT) control verb is now supported by the JIT compiler.
140    17. The Unicode data tables have been updated to Unicode 6.1.0.
142    18. Added --file-list option to pcregrep.
144    19. Added binary file support to pcregrep, including the -a, --binary-files,
145        -I, and --text options.
147    20. The madvise function is renamed for posix_madvise for QNX compatibility
148        reasons. Fixed by Giuseppe D'Angelo.
150    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
152    22. Changed the option for creating symbolic links for 16-bit man pages from
153        -s to -sf so that re-installing does not cause issues.
155    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
157    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
158        matches in certain environments (the workspace was not being correctly
159        retained). Also added to pcre_dfa_exec() a simple plausibility check on
160        some of the workspace data at the beginning of a restart.
162    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
163        was not doing so when it should - probably a typo introduced by SVN 528
164        (change 8.10/14).
166    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
167        \w+ when the character tables indicated that \x{c4} was a word character.
168        There were several related cases, all because the tests for doing a table
169        lookup were testing for characters less than 127 instead of 255.
171    27. If a pattern contains capturing parentheses that are not used in a match,
172        their slots in the ovector are set to -1. For those that are higher than
173        any matched groups, this happens at the end of processing. In the case when
174        there were back references that the ovector was too small to contain
175        (causing temporary malloc'd memory to be used during matching), and the
176        highest capturing number was not used, memory off the end of the ovector
177        was incorrectly being set to -1. (It was using the size of the temporary
178        memory instead of the true size.)
180    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
181        ovector size, it uses memory at the end of the block that it has got.
183    29. Check for an overlong MARK name and give an error at compile time. The
184        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
186    30. JIT compiler update.
188    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
189        Rill for the patch.
191    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
193    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
195    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
196        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
197        was enabled.
199    35. Improve JIT code generation for greedy plus quantifier.
201    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
202        1 to "aa" instead of to an empty string. The bug affected repeated groups
203        that could potentially match an empty string.
205    37. Optimizing single character iterators in JIT.
207    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
208        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
209        codepoints that are too big for the mode are faulted, and in a UTF mode,
210        disallowed codepoints are also faulted.
212    39. If PCRE was compiled with UTF support, in three places in the DFA
213        matcher there was code that should only have been obeyed in UTF mode, but
214        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
215        processing when bytes with values greater than 127 were present. In 16-bit
216        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
217        both cases the values are those that cannot be the first data item in a UTF
218        character. The three items that might have provoked this were recursions,
219        possessively repeated groups, and atomic groups.
221    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
222        and pcregrep, because some OS require shared objects to be explicitly
223        passed to ld, causing the link step to fail if they are not.
225    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
226        mode, patterns that started with \h* or \R* might be incorrectly matched.
229    Version 8.30 04-February-2012
230    -----------------------------
232    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
233        name is defined in ctype.h.
235    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
236        only in quite long subpatterns.
238    3.  Removed the function pcre_info(), which has been obsolete and deprecated
239        since it was replaced by pcre_fullinfo() in February 2000.
241    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
242        match a (*MARK), and the match failed at the start of the subject, a
243        reference to memory before the start of the subject could occur. This bug
244        was introduced by fix 17 of release 8.21.
246    5.  A reference to an unset group with zero minimum repetition was giving
247        totally wrong answers (in non-JavaScript-compatibility mode). For example,
248        /(another)?(\1?)test/ matched against "hello world test". This bug was
249        introduced in release 8.13.
251    6.  Add support for 16-bit character strings (a large amount of work involving
252        many changes and refactorings).
254    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
255        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
256        from a file.
258    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
259        rounding is not applied in this particular case).
261    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
262        if they appear, or are escaped, in patterns.
264    10. Get rid of a number of -Wunused-but-set-variable warnings.
266    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
267        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
268        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
269        also returns the mark "x". This bug applied to capturing parentheses,
270        non-capturing parentheses, and atomic parentheses. It also applied to some
271        assertions.
273    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
274        information out of configure.ac instead of relying on pcre.h.generic, which
275        is not stored in the repository.
277    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
278        -lreadline.
280    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
282    15. Applied Graycode's patch to put the top-level frame on the stack rather
283        than the heap when not using the stack for recursion. This gives a
284        performance improvement in many cases when recursion is not deep.
286    16. Experimental code added to "pcretest -C" to output the stack frame size.
289    Version 8.21 12-Dec-2011
290    ------------------------
292    1.  Updating the JIT compiler.
294    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
295        are added as well.
297    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
298        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
299        calling _pcre_jit_exec. Some extra comments are added.
301    4.  (*MARK) settings inside atomic groups that do not contain any capturing
302        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
303        was introduced by change 18 for 8.20.
305    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
306        ECMA-262 standard.
308    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
309        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
310        This bug was probably introduced by change 9 of 8.13.
312    7.  While fixing 6 above, I noticed that a number of other items were being
313        incorrectly rejected as "not fixed length". This arose partly because newer
314        opcodes had not been added to the fixed-length checking code. I have (a)
315        corrected the bug and added tests for these items, and (b) arranged for an
316        error to occur if an unknown opcode is encountered while checking for fixed
317        length instead of just assuming "not fixed length". The items that were
318        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
319        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
320        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
322    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
323        being incorrectly compiled and would have given unpredicatble results.
325    9.  A possessively repeated subpattern with minimum repeat count greater than
326        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
327        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
328        the first (A) could occur when it should not.
330    10. Add a cast and remove a redundant test from the code.
332    11. JIT should use pcre_malloc/pcre_free for allocation.
334    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
335        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
336        is anything other than /usr, -L is still shown).
338    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
340    14. Perl does not support \N without a following name in a [] class; PCRE now
341        also gives an error.
343    15. If a forward reference was repeated with an upper limit of around 2000,
344        it caused the error "internal error: overran compiling workspace". The
345        maximum number of forward references (including repeats) was limited by the
346        internal workspace, and dependent on the LINK_SIZE. The code has been
347        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
348        the default depends on LINK_SIZE. There is a new upper limit (for safety)
349        of around 200,000 forward references. While doing this, I also speeded up
350        the filling in of repeated forward references.
352    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
353        incorrectly expecting the subject to contain another "a" after the start.
355    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
356        in the match, the SKIP should be ignored. This was not happening; instead
357        the SKIP was being treated as NOMATCH. For patterns such as
358        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
359        tested.
361    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
362        now much more compatible with Perl, in particular in cases where the result
363        is a non-match for a non-anchored pattern. For example, if
364        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
365        "m", where previously it did not return a name. A side effect of this
366        change is that for partial matches, the last encountered mark name is
367        returned, as for non matches. A number of tests that were previously not
368        Perl-compatible have been moved into the Perl-compatible test files. The
369        refactoring has had the pleasing side effect of removing one argument from
370        the match() function, thus reducing its stack requirements.
372    19. If the /S+ option was used in pcretest to study a pattern using JIT,
373        subsequent uses of /S (without +) incorrectly behaved like /S+.
375    21. Retrieve executable code size support for the JIT compiler and fixing
376        some warnings.
378    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
379        not work when the shorter character appeared right at the end of the
380        subject string.
382    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
383        systems.
385    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
386        output it when the /M option is used in pcretest.
388    25. The CheckMan script was not being included in the distribution. Also, added
389        an explicit "perl" to run Perl scripts from the PrepareRelease script
390        because this is reportedly needed in Windows.
392    26. If study data was being save in a file and studying had not found a set of
393        "starts with" bytes for the pattern, the data written to the file (though
394        never used) was taken from uninitialized memory and so caused valgrind to
395        complain.
397    27. Updated RunTest.bat as provided by Sheri Pierce.
399    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
401    29. Computation of memory usage for the table of capturing group names was
402        giving an unnecessarily large value.
405    Version 8.20 21-Oct-2011
406    ------------------------
408    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
409        a POSIX class. After further experiments with Perl, which convinced me that
410        Perl has bugs and confusions, a closing square bracket is no longer allowed
411        in a POSIX name. This bug also affected patterns with classes that started
412        with full stops.
414    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
415        captured substring, but while checking the failing first alternative,
416        substring 1 is temporarily captured. If the output vector supplied to
417        pcre_exec() was not big enough for this capture, the yield of the function
418        was still zero ("insufficient space for captured substrings"). This cannot
419        be totally fixed without adding another stack variable, which seems a lot
420        of expense for a edge case. However, I have improved the situation in cases
421        such as /(a)(b)x|abc/ matched against "abc", where the return code
422        indicates that fewer than the maximum number of slots in the ovector have
423        been set.
425    3.  Related to (2) above: when there are more back references in a pattern than
426        slots in the output vector, pcre_exec() uses temporary memory during
427        matching, and copies in the captures as far as possible afterwards. It was
428        using the entire output vector, but this conflicts with the specification
429        that only 2/3 is used for passing back captured substrings. Now it uses
430        only the first 2/3, for compatibility. This is, of course, another edge
431        case.
433    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
434        main code base, and can be used by building with --enable-jit. When this is
435        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
436        runtime --no-jit option is given.
438    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
439        ovector, the return from the function was zero, implying that there were
440        other matches that did not fit. The correct "exactly full" value is now
441        returned.
443    6.  If a subpattern that was called recursively or as a subroutine contained
444        (*PRUNE) or any other control that caused it to give a non-standard return,
445        invalid errors such as "Error -26 (nested recursion at the same subject
446        position)" or even infinite loops could occur.
448    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
449        computing the minimum length on reaching *ACCEPT, and so ended up with the
450        wrong value of 1 rather than 0. Further investigation indicates that
451        computing a minimum subject length in the presence of *ACCEPT is difficult
452        (think back references, subroutine calls), and so I have changed the code
453        so that no minimum is registered for a pattern that contains *ACCEPT.
455    8.  If (*THEN) was present in the first (true) branch of a conditional group,
456        it was not handled as intended. [But see 16 below.]
458    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
459        Sheri Pierce.
461    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
462        the first byte in a match must be "a".
464    11. Change 17 for 8.13 increased the recursion depth for patterns like
465        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
466        pattern contains any instances of (*THEN). If it does not, the old
467        optimizations are restored. It would be nice to do this on a per-group
468        basis, but at the moment that is not feasible.
470    12. In some environments, the output of pcretest -C is CRLF terminated. This
471        broke RunTest's code that checks for the link size. A single white space
472        character after the value is now allowed for.
474    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
475        For "fr", it uses the Windows-specific input and output files.
477    14. If (*THEN) appeared in a group that was called recursively or as a
478        subroutine, it did not work as intended. [But see next item.]
480    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
481        pattern fragments (but not containing any | characters). If A and B are
482        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
483        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
484        D. In other words, Perl considers parentheses that do not contain any |
485        characters to be part of a surrounding alternative, whereas PCRE was
486        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
487        differently. PCRE now behaves in the same way as Perl, except in the case
488        of subroutine/recursion calls such as (?1) which have in any case always
489        been different (but PCRE had them first :-).
491    16. Related to 15 above: Perl does not treat the | in a conditional group as
492        creating alternatives. Such a group is treated in the same way as an
493        ordinary group without any | characters when processing (*THEN). PCRE has
494        been changed to match Perl's behaviour.
496    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
497        RunGrepTest script failed.
499    18. Change 22 for version 13 caused atomic groups to use more stack. This is
500        inevitable for groups that contain captures, but it can lead to a lot of
501        stack use in large patterns. The old behaviour has been restored for atomic
502        groups that do not contain any capturing parentheses.
504    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
505        suppress the check for a minimum subject length at run time. (If it was
506        given to pcre_exec() or pcre_dfa_exec() it did work.)
508    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
509        fail to work when decoding hex characters in data strings in EBCDIC
510        environments.
512    21. It appears that in at least one Mac OS environment, the isxdigit() function
513        is implemented as a macro that evaluates to its argument more than once,
514        contravening the C 90 Standard (I haven't checked a later standard). There
515        was an instance in pcretest which caused it to go wrong when processing
516        \x{...} escapes in subject strings. The has been rewritten to avoid using
517        things like p++ in the argument of isxdigit().
520    Version 8.13 16-Aug-2011
521    ------------------------
523    1.  The Unicode data tables have been updated to Unicode 6.0.0.
525    2.  Two minor typos in pcre_internal.h have been fixed.
527    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
528        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
529        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
531    4.  There were a number of related bugs in the code for matching backrefences
532        caselessly in UTF-8 mode when codes for the characters concerned were
533        different numbers of bytes. For example, U+023A and U+2C65 are an upper
534        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
535        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
536        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
537        2-byte code at the end of the subject (it thought there wasn't enough data
538        left).
540    5.  Comprehensive information about what went wrong is now returned by
541        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
542        as the output vector has at least 2 elements. The offset of the start of
543        the failing character and a reason code are placed in the vector.
545    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
546        now returned is for the first byte of the failing character, instead of the
547        last byte inspected. This is an incompatible change, but I hope it is small
548        enough not to be a problem. It makes the returned offset consistent with
549        pcre_exec() and pcre_dfa_exec().
551    7.  pcretest now gives a text phrase as well as the error number when
552        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
553        failure, the offset and reason code are output.
555    8.  When \R was used with a maximizing quantifier it failed to skip backwards
556        over a \r\n pair if the subsequent match failed. Instead, it just skipped
557        back over a single character (\n). This seems wrong (because it treated the
558        two characters as a single entity when going forwards), conflicts with the
559        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
560        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
561        has been changed.
563    9.  Some internal refactoring has changed the processing so that the handling
564        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
565        time (the PCRE_DOTALL option was changed this way some time ago: version
566        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
567        which was always a bit of a fudge. It also means that there is one less
568        argument for the match() function, which reduces its stack requirements
569        slightly. This change also fixes an incompatibility with Perl: the pattern
570        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
572    10. More internal refactoring has drastically reduced the number of recursive
573        calls to match() for possessively repeated groups such as (abc)++ when
574        using pcre_exec().
576    11. While implementing 10, a number of bugs in the handling of groups were
577        discovered and fixed:
579        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
580        (a|)*(?1) gave a compile-time internal error.
581        ((a|)+)+  did not notice that the outer group could match an empty string.
582        (^a|^)+   was not marked as anchored.
583        (.*a|.*)+ was not marked as matching at start or after a newline.
585    12. Yet more internal refactoring has removed another argument from the match()
586        function. Special calls to this function are now indicated by setting a
587        value in a variable in the "match data" data block.
589    13. Be more explicit in pcre_study() instead of relying on "default" for
590        opcodes that mean there is no starting character; this means that when new
591        ones are added and accidentally left out of pcre_study(), testing should
592        pick them up.
594    14. The -s option of pcretest has been documented for ages as being an old
595        synonym of -m (show memory usage). I have changed it to mean "force study
596        for every regex", that is, assume /S for every regex. This is similar to -i
597        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
598        using it. It makes it easier to run collections of tests with and without
599        study enabled, and thereby test pcre_study() more easily. All the standard
600        tests are now run with and without -s (but some patterns can be marked as
601        "never study" - see 20 below).
603    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
604        restoration of the capturing data to the outer values was not happening
605        correctly.
607    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
608        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
609        pattern had matched an empty string, and so incorrectly returned a no
610        match.
612    17. There was optimizing code for the last branch of non-capturing parentheses,
613        and also for the obeyed branch of a conditional subexpression, which used
614        tail recursion to cut down on stack usage. Unfortunately, now that there is
615        the possibility of (*THEN) occurring in these branches, tail recursion is
616        no longer possible because the return has to be checked for (*THEN). These
617        two optimizations have therefore been removed. [But see 8.20/11 above.]
619    18. If a pattern containing \R was studied, it was assumed that \R always
620        matched two bytes, thus causing the minimum subject length to be
621        incorrectly computed because \R can also match just one byte.
623    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
624        was incorrectly computed.
626    20. If /S is present twice on a test pattern in pcretest input, it now
627        *disables* studying, thereby overriding the use of -s on the command line
628        (see 14 above). This is necessary for one or two tests to keep the output
629        identical in both cases.
631    21. When (*ACCEPT) was used in an assertion that matched an empty string and
632        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
634    22. When an atomic group that contained a capturing parenthesis was
635        successfully matched, but the branch in which it appeared failed, the
636        capturing was not being forgotten if a higher numbered group was later
637        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
638        group 1 to "a", when in fact it should be unset. This applied to multi-
639        branched capturing and non-capturing groups, repeated or not, and also to
640        positive assertions (capturing in negative assertions does not happen
641        in PCRE) and also to nested atomic groups.
643    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
644        subject after a captured substring, to make it easier to tell which of a
645        number of identical substrings has been captured.
647    24. The way atomic groups are processed by pcre_exec() has been changed so that
648        if they are repeated, backtracking one repetition now resets captured
649        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
650        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
651        "aaa". Previously, it would have been "a". As part of this code
652        refactoring, the way recursive calls are handled has also been changed.
654    25. If an assertion condition captured any substrings, they were not passed
655        back unless some other capturing happened later. For example, if
656        (?(?=(a))a) was matched against "a", no capturing was returned.
658    26. When studying a pattern that contained subroutine calls or assertions,
659        the code for finding the minimum length of a possible match was handling
660        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
661        group 1 called group 2 while simultaneously a separate group 2 called group
662        1). A stack overflow occurred in this case. I have fixed this by limiting
663        the recursion depth to 10.
665    27. Updated RunTest.bat in the distribution to the version supplied by Tom
666        Fortmann. This supports explicit test numbers on the command line, and has
667        argument validation and error reporting.
669    28. An instance of \X with an unlimited repeat could fail if at any point the
670        first character it looked at was a mark character.
672    29. Some minor code refactoring concerning Unicode properties and scripts
673        should reduce the stack requirement of match() slightly.
675    30. Added the '=' option to pcretest to check the setting of unused capturing
676        slots at the end of the pattern, which are documented as being -1, but are
677        not included in the return count.
679    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
680        compiled something random. Now it gives a compile-time error (as does
681        Perl).
683    32. A *MARK encountered during the processing of a positive assertion is now
684        recorded and passed back (compatible with Perl).
686    33. If --only-matching or --colour was set on a pcregrep call whose pattern
687        had alternative anchored branches, the search for a second match in a line
688        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
689        matched the line "0102" twice. The same bug affected patterns that started
690        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
691        twice.
693    34. Previously, PCRE did not allow quantification of assertions. However, Perl
694        does, and because of capturing effects, quantifying parenthesized
695        assertions may at times be useful. Quantifiers are now allowed for
696        parenthesized assertions.
698    35. A minor code tidy in pcre_compile() when checking options for \R usage.
700    36. \g was being checked for fancy things in a character class, when it should
701        just be a literal "g".
703    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
704        appearance of a nested POSIX class supersedes an apparent external class.
705        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
706        unescaped square brackets may also appear as part of class names. For
707        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
708        more like Perl. (But see 8.20/1 above.)
710    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
711        was because it thought it was \N{name}, which is not supported).
713    39. Add minix to OS list not supporting the -S option in pcretest.
715    40. PCRE tries to detect cases of infinite recursion at compile time, but it
716        cannot analyze patterns in sufficient detail to catch mutual recursions
717        such as ((?1))((?2)). There is now a runtime test that gives an error if a
718        subgroup is called recursively as a subpattern for a second time at the
719        same position in the subject string. In previous releases this might have
720        been caught by the recursion limit, or it might have run out of stack.
722    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
723        happen only once. PCRE was, however incorrectly giving a compile time error
724        "recursive call could loop indefinitely" because it cannot analyze the
725        pattern in sufficient detail. The compile time test no longer happens when
726        PCRE is compiling a conditional subpattern, but actual runaway loops are
727        now caught at runtime (see 40 above).
729    42. It seems that Perl allows any characters other than a closing parenthesis
730        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
731        has been changed to be the same.
733    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
734        as not to get warnings when autogen.sh is called. Also changed
735        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
737    44. To help people who use pcregrep to scan files containing exceedingly long
738        lines, the following changes have been made:
740        (a) The default value of the buffer size parameter has been increased from
741            8K to 20K. (The actual buffer used is three times this size.)
743        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
744            PCRE is built.
746        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
747            to be set at run time.
749        (d) Numerical values in pcregrep options can be followed by K or M, for
750            example --buffer-size=50K.
752        (e) If a line being scanned overflows pcregrep's buffer, an error is now
753            given and the return code is set to 2.
755    45. Add a pointer to the latest mark to the callout data block.
757    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
758        partial match of an empty string instead of no match. This was specific to
759        the use of ".".
761    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
762        complete match instead of a partial match. This bug was dependent on both
763        the PCRE_UTF8 and PCRE_DOTALL options being set.
765    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
766        starting byte set, because \b was not being ignored.
769    Version 8.12 15-Jan-2011
770    ------------------------
772    1.  Fixed some typos in the markup of the man pages, and wrote a script that
773        checks for such things as part of the documentation building process.
775    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
776        --match-limit and --recursion-limit options (added for 8.11). In
777        particular, this made one of the standard tests fail. (The integer value
778        went into the wrong half of a long int.)
780    3.  If the --colour option was given to pcregrep with -v (invert match), it
781        did strange things, either producing crazy output, or crashing. It should,
782        of course, ignore a request for colour when reporting lines that do not
783        match.
785    4.  Another pcregrep bug caused similar problems if --colour was specified with
786        -M (multiline) and the pattern match finished with a line ending.
788    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
789        matched in multiline mode, the following line was shown as part of the
790        match. This seems wrong, so I have changed it.
792    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
793        the check for further matches in the same line (so they could be coloured)
794        to overrun the end of the current line. If another match was found, it was
795        incorrectly shown (and then shown again when found in the next line).
797    7.  If pcregrep was compiled under Windows, there was a reference to the
798        function pcregrep_exit() before it was defined. I am assuming this was
799        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
800        reported by a user. I've moved the definition above the reference.
803    Version 8.11 10-Dec-2010
804    ------------------------
806    1.  (*THEN) was not working properly if there were untried alternatives prior
807        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
808        backtracked to try for "b" instead of moving to the next alternative branch
809        at the same level (in this case, to look for "c"). The Perl documentation
810        is clear that when (*THEN) is backtracked onto, it goes to the "next
811        alternative in the innermost enclosing group".
813    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
814        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
815        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
816        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
817        (*THEN).
819    3.  If \s appeared in a character class, it removed the VT character from
820        the class, even if it had been included by some previous item, for example
821        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
822        of \s, but is part of the POSIX "space" class.)
824    4.  A partial match never returns an empty string (because you can always
825        match an empty string at the end of the subject); however the checking for
826        an empty string was starting at the "start of match" point. This has been
827        changed to the "earliest inspected character" point, because the returned
828        data for a partial match starts at this character. This means that, for
829        example, /(?<=abc)def/ gives a partial match for the subject "abc"
830        (previously it gave "no match").
832    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
833        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
834        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
835        has an implication that the given string is incomplete (because a partial
836        match is preferred over a full match). For this reason, these items now
837        give a partial match in this situation. [Aside: previously, the one case
838        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
839        match rather than a full match, which was wrong by the old rules, but is
840        now correct.]
842    6.  There was a bug in the handling of #-introduced comments, recognized when
843        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
844        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
845        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
846        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
847        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
848        places in pcre_compile().
850    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
851        comments when looking ahead for named forward references to subpatterns,
852        the only newline sequence it recognized was NL. It now handles newlines
853        according to the set newline convention.
855    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
856        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
857        cater for a lack of strerror(). These oversights have been fixed.
859    9.  Added --match-limit and --recursion-limit to pcregrep.
861    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
863    11. When the -o option was used, pcregrep was setting a return code of 1, even
864        when matches were found, and --line-buffered was not being honoured.
866    12. Added an optional parentheses number to the -o and --only-matching options
867        of pcregrep.
869    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
870        can match an empty string. The code to do it in pcretest and pcredemo
871        needed fixing:
873        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
874            only one byte after an empty string match just before CRLF (this case
875            just got forgotten; "any" and "anycrlf" were OK).
877        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
878            mode when an empty string match preceded an ASCII character followed by
879            a non-ASCII character. (The code for advancing by one character rather
880            than one byte was nonsense.)
882        (c) The pcredemo.c sample program did not have any code at all to handle
883            the cases when CRLF is a valid newline sequence.
885    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
886        as a starting offset was within the subject string. There is now a new
887        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
888        negative or greater than the length of the string. In order to test this,
889        pcretest is extended to allow the setting of negative starting offsets.
891    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
892        starting offset points to the beginning of a UTF-8 character was
893        unnecessarily clumsy. I tidied it up.
895    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
896        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
898    17. Nobody had reported that the --include_dir option, which was added in
899        release 7.7 should have been called --include-dir (hyphen, not underscore)
900        for compatibility with GNU grep. I have changed it to --include-dir, but
901        left --include_dir as an undocumented synonym, and the same for
902        --exclude-dir, though that is not available in GNU grep, at least as of
903        release 2.5.4.
905    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
906        characters from a string of bytes) have been redefined so as not to use
907        loops, in order to improve performance in some environments. At the same
908        time, I abstracted some of the common code into auxiliary macros to save
909        repetition (this should not affect the compiled code).
911    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
912        compile-time error is now given if \c is not followed by an ASCII
913        character, that is, a byte less than 128. (In EBCDIC mode, the code is
914        different, and any byte value is allowed.)
916    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
917        START_OPTIMIZE option, which is now allowed at compile time - but just
918        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
919        to pcregrep and other applications that have no direct access to PCRE
920        options. The new /Y option in pcretest sets this option when calling
921        pcre_compile().
923    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
924        back references. Groups containing recursive back references were forced to
925        be atomic by that change, but in the case of named groups, the amount of
926        memory required was incorrectly computed, leading to "Failed: internal
927        error: code overflow". This has been fixed.
929    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
930        pcretest.c, to avoid build problems in some Borland environments.
933    Version 8.10 25-Jun-2010
934    ------------------------
936    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
937        THEN.
939    2.  (*ACCEPT) was not working when inside an atomic group.
941    3.  Inside a character class, \B is treated as a literal by default, but
942        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
943        causes the error). The code is unchanged, but I tidied the documentation.
945    4.  Inside a character class, PCRE always treated \R and \X as literals,
946        whereas Perl faults them if its -w option is set. I have changed PCRE so
947        that it faults them when PCRE_EXTRA is set.
949    5.  Added support for \N, which always matches any character other than
950        newline. (It is the same as "." when PCRE_DOTALL is not set.)
952    6.  When compiling pcregrep with newer versions of gcc which may have
953        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
954        declared with attribute warn_unused_result" were given. Just casting the
955        result to (void) does not stop the warnings; a more elaborate fudge is
956        needed. I've used a macro to implement this.
958    7.  Minor change to pcretest.c to avoid a compiler warning.
960    8.  Added four artifical Unicode properties to help with an option to make
961        \s etc use properties (see next item). The new properties are: Xan
962        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
964    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
965        use Unicode properties. (*UCP) at the start of a pattern can be used to set
966        this option. Modified pcretest to add /W to test this facility. Added
967        REG_UCP to make it available via the POSIX interface.
969    10. Added --line-buffered to pcregrep.
971    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
972        studied, and the match started with a letter with a code point greater than
973        127 whose first byte was different to the first byte of the other case of
974        the letter, the other case of this starting letter was not recognized
975        (#976).
977    12. If a pattern that was studied started with a repeated Unicode property
978        test, for example, \p{Nd}+, there was the theoretical possibility of
979        setting up an incorrect bitmap of starting bytes, but fortunately it could
980        not have actually happened in practice until change 8 above was made (it
981        added property types that matched character-matching opcodes).
983    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
984        possible starting bytes for non-anchored patterns.
986    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
987        \R, and also a number of cases that involve Unicode properties, both
988        explicit and implicit when PCRE_UCP is set.
990    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
991        input, it could crash or give wrong results if characters with values
992        greater than 0xc0 were present in the subject string. (Detail: it assumed
993        UTF-8 input when processing these items.)
995    16. Added a lot of (int) casts to avoid compiler warnings in systems where
996        size_t is 64-bit (#991).
998    17. Added a check for running out of memory when PCRE is compiled with
999        --disable-stack-for-recursion (#990).
1001    18. If the last data line in a file for pcretest does not have a newline on
1002        the end, a newline was missing in the output.
1004    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1005        less than 128) in its various bitmaps. However, there is a facility for
1006        generating tables according to the current locale when PCRE is compiled. It
1007        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1008        characters, are recognized by isspace() and therefore were getting set in
1009        these tables, and indeed these tables seem to approximate to ISO 8859. This
1010        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1011        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1012        which of course cannot start UTF-8 characters. I have changed the code so
1013        that only real ASCII characters (less than 128) and the correct starting
1014        bytes for UTF-8 encodings are set for characters greater than 127 when in
1015        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1016        altogether.)
1018    20. Added the /T option to pcretest so as to be able to run tests with non-
1019        standard character tables, thus making it possible to include the tests
1020        used for 19 above in the standard set of tests.
1022    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1023        reference to a subpattern the other side of a comment that contains an
1024        opening parenthesis caused either an internal compiling error, or a
1025        reference to the wrong subpattern.
1028    Version 8.02 19-Mar-2010
1029    ------------------------
1031    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1033    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1034        configured.
1036    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1037        original author of that file, following a query about its status.
1039    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1040        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1042    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1043        quantifier applied to a forward-referencing subroutine call, could compile
1044        incorrect code or give the error "internal error: previously-checked
1045        referenced subpattern not found".
1047    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1048        variables to point to external functions. For these systems, therefore,
1049        pcre_malloc etc. are now initialized to local functions that call the
1050        relevant global functions.
1052    7.  There were two entries missing in the vectors called coptable and poptable
1053        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1054        I've fixed the data, and added a kludgy way of testing at compile time that
1055        the lengths are correct (equal to the number of opcodes).
1057    8.  Following on from 7, I added a similar kludge to check the length of the
1058        eint vector in pcreposix.c.
1060    9.  Error texts for pcre_compile() are held as one long string to avoid too
1061        much relocation at load time. To find a text, the string is searched,
1062        counting zeros. There was no check for running off the end of the string,
1063        which could happen if a new error number was added without updating the
1064        string.
1066    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1068    11. \K was not working if it appeared in an atomic group or in a group that
1069        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1070        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1071        the assertion is positive, but not if it is negative.
1073    12. Change 11 fortuitously reduced the size of the stack frame used in the
1074        "match()" function of pcre_exec.c by one pointer. Forthcoming
1075        implementation of support for (*MARK) will need an extra pointer on the
1076        stack; I have reserved it now, so that the stack frame size does not
1077        decrease.
1079    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1080        item in branch that calls a recursion is a subroutine call - as in the
1081        second branch in the above example - was incorrectly given the compile-
1082        time error "recursive call could loop indefinitely" because pcre_compile()
1083        was not correctly checking the subroutine for matching a non-empty string.
1085    14. The checks for overrunning compiling workspace could trigger after an
1086        overrun had occurred. This is a "should never occur" error, but it can be
1087        triggered by pathological patterns such as hundreds of nested parentheses.
1088        The checks now trigger 100 bytes before the end of the workspace.
1090    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1093    Version 8.01 19-Jan-2010
1094    ------------------------
1096    1.  If a pattern contained a conditional subpattern with only one branch (in
1097        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1098        computed the wrong minimum data length (which is of course zero for such
1099        subpatterns). This could cause incorrect "no match" results.
1101    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1102        the pattern is reset in the first branch, pcre_compile() failed with
1103        "internal error: code overflow at offset...". This happened only when
1104        the reset was to the original external option setting. (An optimization
1105        abstracts leading options settings into an external setting, which was the
1106        cause of this.)
1108    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1109        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1110        assertion pattern did not match (meaning that the assertion was true), it
1111        was incorrectly treated as false if the SKIP had been reached during the
1112        matching. This also applied to assertions used as conditions.
1114    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1115        assertion subpattern, including such a pattern used as a condition,
1116        unpredictable results occurred, instead of the error return
1119    5.  The C++ GlobalReplace function was not working like Perl for the special
1120        situation when an empty string is matched. It now does the fancy magic
1121        stuff that is necessary.
1123    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1124        removed. (These were left over from very, very early versions of PCRE.)
1126    7.  Some cosmetic changes to the code to make life easier when compiling it
1127        as part of something else:
1129        (a) Change DEBUG to PCRE_DEBUG.
1131        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1132            called "current" as "current_branch", to prevent a collision with the
1133            Linux macro when compiled as a kernel module.
1135        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1136            prevent a collision with the Linux macro when compiled as a kernel
1137            module.
1139    8.  In pcre_compile() there are some checks for integer overflows that used to
1140        cast potentially large values to (double). This has been changed to that
1141        when building, a check for int64_t is made, and if it is found, it is used
1142        instead, thus avoiding the use of floating point arithmetic. (There is no
1143        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1144        double.
1146    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1147        2005 (difference between two addresses compared to an unsigned value).
1149    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1150        custom one, because of the following reported problem in Windows:
1152          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1153              under Win32.
1154          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1155              therefore missing the function definition.
1156          - The compiler thus generates a "C" signature for the test function.
1157          - The linker fails to find the "C" function.
1158          - PCRE fails to configure if asked to do so against libbz2.
1160    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1161        messages were output:
1163          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1164          rerunning libtoolize, to keep the correct libtool macros in-tree.
1165          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1167        I have done both of these things.
1169    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1170        most of the time, it *can* run out if it is given a pattern that contains a
1171        runaway infinite recursion. I updated the discussion in the pcrestack man
1172        page.
1174    13. Now that we have gone to the x.xx style of version numbers, the minor
1175        version may start with zero. Using 08 or 09 is a bad idea because users
1176        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1177        interpreted as invalid octal numbers. I've updated the previous comment in
1178        configure.ac, and also added a check that gives an error if 08 or 09 are
1179        used.
1181    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1182        causing partial matching to fail when the end of the subject matched \W
1183        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1185    15. There were some discrepancies between the declarations in pcre_internal.h
1186        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1187        their definitions. The declarations used "const uschar *" and the
1188        definitions used USPTR. Even though USPTR is normally defined as "const
1189        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1190        reported that: "This difference in casting confuses some C++ compilers, for
1191        example, SunCC recognizes above declarations as different functions and
1192        generates broken code for hbpcre." I have changed the declarations to use
1193        USPTR.
1195    16. GNU libtool is named differently on some systems. The autogen.sh script now
1196        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1197        (FreeBSD).
1199    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1200        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1201        comment: "Figure out how to create a longlong from a string: strtoll and
1202        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1203        instance, but it only takes 2 args instead of 3!"
1205    18. A subtle bug concerned with back references has been fixed by a change of
1206        specification, with a corresponding code fix. A pattern such as
1207        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1208        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1209        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1210        same bug. Such groups have to be quantified to be useful, or contained
1211        inside another quantified group. (If there's no repetition, the reference
1212        can never match.) The problem arises because, having left the group and
1213        moved on to the rest of the pattern, a later failure that backtracks into
1214        the group uses the captured value from the final iteration of the group
1215        rather than the correct earlier one. I have fixed this in PCRE by forcing
1216        any group that contains a reference to itself to be an atomic group; that
1217        is, there cannot be any backtracking into it once it has completed. This is
1218        similar to recursive and subroutine calls.
1221    Version 8.00 19-Oct-09
1222    ----------------------
1224    1.  The table for translating pcre_compile() error codes into POSIX error codes
1225        was out-of-date, and there was no check on the pcre_compile() error code
1226        being within the table. This could lead to an OK return being given in
1227        error.
1229    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1230        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1231        in a Windows environment.
1233    3.  The pcregrep --count option prints the count for each file even when it is
1234        zero, as does GNU grep. However, pcregrep was also printing all files when
1235        --files-with-matches was added. Now, when both options are given, it prints
1236        counts only for those files that have at least one match. (GNU grep just
1237        prints the file name in this circumstance, but including the count seems
1238        more useful - otherwise, why use --count?) Also ensured that the
1239        combination -clh just lists non-zero counts, with no names.
1241    4.  The long form of the pcregrep -F option was incorrectly implemented as
1242        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1243        but it seems right to fix it, and I didn't think it was worth preserving
1244        the old behaviour.
1246    5.  The command line items --regex=pattern and --regexp=pattern were not
1247        recognized by pcregrep, which required --regex pattern or --regexp pattern
1248        (with a space rather than an '='). The man page documented the '=' forms,
1249        which are compatible with GNU grep; these now work.
1251    6.  No libpcreposix.pc file was created for pkg-config; there was just
1252        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1254    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1255        when UCP support is not needed, by modifying the Python script that
1256        generates it from Unicode data files. This should not matter if the module
1257        is correctly used as a library, but I received one complaint about 50K of
1258        unwanted data. My guess is that the person linked everything into his
1259        program rather than using a library. Anyway, it does no harm.
1261    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1262        was a minimum greater than 1 for a wide character in a possessive
1263        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1264        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1265        character. Chaos in the form of incorrect output or a compiling loop could
1266        result.
1268    9.  The restrictions on what a pattern can contain when partial matching is
1269        requested for pcre_exec() have been removed. All patterns can now be
1270        partially matched by this function. In addition, if there are at least two
1271        slots in the offset vector, the offset of the earliest inspected character
1272        for the match and the offset of the end of the subject are set in them when
1273        PCRE_ERROR_PARTIAL is returned.
1275    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1276        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1277        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1278        and may be more useful for multi-segment matching.
1280    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1281        used to be given if ever the end of the subject was reached; now it is
1282        given only if matching could not proceed because another character was
1283        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1284        string "Z", which now yields "no match" instead of "partial match". In the
1285        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1286        final character ended with (*FAIL).
1288    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1289        if the pattern had a "must contain" character that was already found in the
1290        earlier partial match, unless partial matching was again requested. For
1291        example, with the pattern /dog.(body)?/, the "must contain" character is
1292        "g". If the first part-match was for the string "dog", restarting with
1293        "sbody" failed. This bug has been fixed.
1295    13. The string returned by pcre_dfa_exec() after a partial match has been
1296        changed so that it starts at the first inspected character rather than the
1297        first character of the match. This makes a difference only if the pattern
1298        starts with a lookbehind assertion or \b or \B (\K is not supported by
1299        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1300        matching functions compatible, and I think it's the right thing to do.
1302    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1303        so that the demonstration program is easily available in environments where
1304        PCRE has not been installed from source.
1306    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1307        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1308        library.
1310    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1311        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1312        is not the first non-POSIX option to be added. Clearly some people find
1313        these options useful.
1315    17. If a caller to the POSIX matching function regexec() passes a non-zero
1316        value for nmatch with a NULL value for pmatch, the value of
1317        nmatch is forced to zero.
1319    18. RunGrepTest did not have a test for the availability of the -u option of
1320        the diff command, as RunTest does. It now checks in the same way as
1321        RunTest, and also checks for the -b option.
1323    19. If an odd number of negated classes containing just a single character
1324        interposed, within parentheses, between a forward reference to a named
1325        subpattern and the definition of the subpattern, compilation crashed with
1326        an internal error, complaining that it could not find the referenced
1327        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1328        [The bug was that it was starting one character too far in when skipping
1329        over the character class, thus treating the ] as data rather than
1330        terminating the class. This meant it could skip too much.]
1332    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1333        /g option in pcretest when the pattern contains \K, which makes it possible
1334        to have an empty string match not at the start, even when the pattern is
1335        anchored. Updated pcretest and pcredemo to use this option.
1337    21. If the maximum number of capturing subpatterns in a recursion was greater
1338        than the maximum at the outer level, the higher number was returned, but
1339        with unset values at the outer level. The correct (outer level) value is
1340        now given.
1342    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1343        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1344        make it do so. The string so far is captured, making this feature
1345        compatible with Perl.
1347    23. The tests have been re-organized, adding tests 11 and 12, to make it
1348        possible to check the Perl 5.10 features against Perl 5.10.
1350    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1351        pattern matches a fixed length string. PCRE did not allow this; now it
1352        does. Neither allows recursion.
1354    25. I finally figured out how to implement a request to provide the minimum
1355        length of subject string that was needed in order to match a given pattern.
1356        (It was back references and recursion that I had previously got hung up
1357        on.) This code has now been added to pcre_study(); it finds a lower bound
1358        to the length of subject needed. It is not necessarily the greatest lower
1359        bound, but using it to avoid searching strings that are too short does give
1360        some useful speed-ups. The value is available to calling programs via
1361        pcre_fullinfo().
1363    26. While implementing 25, I discovered to my embarrassment that pcretest had
1364        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1365        study optimizations had never been tested with that matching function.
1366        Oops. What is worse, even when it was passed study data, there was a bug in
1367        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1368        were also very few tests of studied patterns with pcre_dfa_exec().
1370    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1371        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1372        on the other side of the coin, they are no longer allowed to have different
1373        names, because these cannot be distinguished in PCRE, and this has caused
1374        confusion. (This is a difference from Perl.)
1376    28. When duplicate subpattern names are present (necessarily with different
1377        numbers, as required by 27 above), and a test is made by name in a
1378        conditional pattern, either for a subpattern having been matched, or for
1379        recursion in such a pattern, all the associated numbered subpatterns are
1380        tested, and the overall condition is true if the condition is true for any
1381        one of them. This is the way Perl works, and is also more like the way
1382        testing by number works.
1385    Version 7.9 11-Apr-09
1386    ---------------------
1388    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1389        (pcretest), all targets were linked against these libraries. This included
1390        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1391        libraries. This caused unwanted dependencies to be created. This problem
1392        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1393        pcretest is linked with readline.
1395    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1396        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1397        moved outside it again, because FALSE and TRUE are already defined in AIX,
1398        but BOOL is not.
1400    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1401        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1403    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1404        hyphens) following file names and line numbers when outputting matching
1405        lines. This is not true; no spaces are inserted. I have also clarified the
1406        wording for the --colour (or --color) option.
1408    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1409        was not coloured; this is different to GNU grep, so I have changed it to be
1410        the same.
1412    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1413        each matching line was coloured. Now it goes on to look for further matches
1414        of any of the test patterns, which is the same behaviour as GNU grep.
1416    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1417        doesn't make sense to accept an empty string match in pcregrep, so I have
1418        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1419        seems to be how GNU grep behaves.
1421    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1422        start or after a newline", because the conditional assertion was not being
1423        correctly handled. The rule now is that both the assertion and what follows
1424        in the first alternative must satisfy the test.
1426    9.  If auto-callout was enabled in a pattern with a conditional group whose
1427        condition was an assertion, PCRE could crash during matching, both with
1428        pcre_exec() and pcre_dfa_exec().
1430    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1431        used for matching.
1433    11. Unicode property support in character classes was not working for
1434        characters (bytes) greater than 127 when not in UTF-8 mode.
1436    12. Added the -M command line option to pcretest.
1438    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1440    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1442    16. Added comments and documentation about mis-use of no_arg in the C++
1443        wrapper.
1445    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1446        from Martin Jerabek that uses macro names for all relevant character and
1447        string constants.
1449    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1450        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1451        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1452        these, but not everybody uses configure.
1454    19. A conditional group that had only one branch was not being correctly
1455        recognized as an item that could match an empty string. This meant that an
1456        enclosing group might also not be so recognized, causing infinite looping
1457        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1458        with the subject "ab", where knowledge that the repeated group can match
1459        nothing is needed in order to break the loop.
1461    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1462        exec(), but without supplying a callout function, matching went wrong.
1464    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1465        leak if the size of the offset vector was greater than 30. When the vector
1466        is smaller, the saved offsets during recursion go onto a local stack
1467        vector, but for larger vectors malloc() is used. It was failing to free
1468        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1469        error, in fact).
1471    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1472        heapframe that is used only when UTF-8 support is enabled. This caused no
1473        problem, but was untidy.
1475    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1476        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1477        included within another project.
1479    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1480        slightly modified by me:
1482          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1483              not building pcregrep.
1485          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1486              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1488    25. Forward references, both numeric and by name, in patterns that made use of
1489        duplicate group numbers, could behave incorrectly or give incorrect errors,
1490        because when scanning forward to find the reference group, PCRE was not
1491        taking into account the duplicate group numbers. A pattern such as
1492        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1494    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1495        the feature of a custom pointer more persuasive (as requested by a user).
1497    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1498        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1499        pre-defined.
1501    28. Added support for (*UTF8) at the start of a pattern.
1503    29. Arrange for flags added by the "release type" setting in CMake to be shown
1504        in the configuration summary.
1507    Version 7.8 05-Sep-08
1508    ---------------------
1510    1.  Replaced UCP searching code with optimized version as implemented for Ad
1511        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1512        stage table and inline lookup instead of a function, giving speed ups of 2
1513        to 5 times on some simple patterns that I tested. Permission was given to
1514        distribute the MultiStage2.py script that generates the tables (it's not in
1515        the tarball, but is in the Subversion repository).
1517    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1518        scripts.
1520    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1521        a group with a zero qualifier. The result of the study could be incorrect,
1522        or the function might crash, depending on the pattern.
1524    4.  Caseless matching was not working for non-ASCII characters in back
1525        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1526        It now works when Unicode Property Support is available.
1528    5.  In pcretest, an escape such as \x{de} in the data was always generating
1529        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1530        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1531        truncation.
1533    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1535    7.  Added two (int) casts to pcregrep when printing the difference of two
1536        pointers, in case they are 64-bit values.
1538    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1539        test 2 if it fails.
1541    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1542        and a #define of that name to empty if it is not externally set. This is to
1543        allow users of MSVC to set it if necessary.
1545    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1546        the convenience functions in the pcre_get.c source file.
1548    11. An option change at the start of a pattern that had top-level alternatives
1549        could cause overwriting and/or a crash. This command provoked a crash in
1550        some environments:
1552          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1554        This potential security problem was recorded as CVE-2008-2371.
1556    12. For a pattern where the match had to start at the beginning or immediately
1557        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1558        pcre_dfa_exec() could read past the end of the passed subject if there was
1559        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1560        pcretest so that it places the subject at the end of its malloc-ed buffer.
1562    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1563        exec() might read past the end of the data buffer in UTF-8 mode.
1565    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1566        the data contained the byte 0x85 as part of a UTF-8 character within its
1567        first line. This applied both to normal and DFA matching.
1569    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1570        /^[^d]*?$/8 failed to match "abc".
1572    16. Added a missing copyright notice to pcrecpp_internal.h.
1574    17. Make it more clear in the documentation that values returned from
1575        pcre_exec() in ovector are byte offsets, not character counts.
1577    18. Tidied a few places to stop certain compilers from issuing warnings.
1579    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1580        supplied by Stefan Weber. I made a further small update for 7.8 because
1581        there is a change of source arrangements: the pcre_searchfuncs.c module is
1582        replaced by pcre_ucd.c.
1585    Version 7.7 07-May-08
1586    ---------------------
1588    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1589        a string to a long long, pretend we don't even have a long long." This is
1590        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1592    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1593        pre-7.6 versions, which defined a global no_arg variable instead of putting
1594        it in the RE class. (See also #8 below.)
1596    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1597        Lopes.
1599    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1601        (1) The include/exclude patterns were being applied to the whole pathnames
1602            of files, instead of just to the final components.
1604        (2) If there was more than one level of directory, the subdirectories were
1605            skipped unless they satisfied the include/exclude conditions. This is
1606            inconsistent with GNU grep (and could even be seen as contrary to the
1607            pcregrep specification - which I improved to make it absolutely clear).
1608            The action now is always to scan all levels of directory, and just
1609            apply the include/exclude patterns to regular files.
1611    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1612        --exclude_dir in the tests to avoid scanning .svn directories.
1614    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1615        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1616        doesn't support NULs in patterns.
1618    7.  Added some missing "const"s to declarations of static tables in
1619        pcre_compile.c and pcre_dfa_exec.c.
1621    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1622        caused by fix #2  above. (Subsequently also a second patch to fix the
1623        first patch. And a third patch - this was a messy problem.)
1625    9.  Applied Craig's patch to remove the use of push_back().
1627    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1628        matching function regexec().
1630    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1631        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1632        references. PCRE supports relative numbers with this syntax (I don't think
1633        Oniguruma does).
1635    12. Previously, a group with a zero repeat such as (...){0} was completely
1636        omitted from the compiled regex. However, this means that if the group
1637        was called as a subroutine from elsewhere in the pattern, things went wrong
1638        (an internal error was given). Such groups are now left in the compiled
1639        pattern, with a new opcode that causes them to be skipped at execution
1640        time.
1642    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1643        to the way PCRE behaves:
1645        (a) A lone ] character is dis-allowed (Perl treats it as data).
1647        (b) A back reference to an unmatched subpattern matches an empty string
1648            (Perl fails the current match path).
1650        (c) A data ] in a character class must be notated as \] because if the
1651            first data character in a class is ], it defines an empty class. (In
1652            Perl it is not possible to have an empty class.) The empty class []
1653            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1654            The negative empty class [^] matches any one character, independently
1655            of the DOTALL setting.
1657    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1658        non-existent subpattern following a character class starting with ']' and
1659        containing () gave an internal compiling error instead of "reference to
1660        non-existent subpattern". Fortunately, when the pattern did exist, the
1661        compiled code was correct. (When scanning forwards to check for the
1662        existencd of the subpattern, it was treating the data ']' as terminating
1663        the class, so got the count wrong. When actually compiling, the reference
1664        was subsequently set up correctly.)
1666    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1667        it was being rejected as not supported by pcre_dfa_exec(), even though
1668        other assertions are supported. I have made pcre_dfa_exec() support
1669        (*FAIL).
1671    16. The implementation of 13c above involved the invention of a new opcode,
1672        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1673        cannot be changed at match time, I realized I could make a small
1674        improvement to matching performance by compiling OP_ALLANY instead of
1675        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1676        on the OP_ANY path.
1678    17. Compiling pcretest on Windows with readline support failed without the
1679        following two fixes: (1) Make the unistd.h include conditional on
1680        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1682    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1683        ncurses library to be included for pcretest when ReadLine support is
1684        requested, but also to allow for it to be overridden. This patch came from
1685        Daniel Bergström.
1687    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1688        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1689        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1690        spotting this.
1693    Version 7.6 28-Jan-08
1694    ---------------------
1696    1.  A character class containing a very large number of characters with
1697        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1698        overflow.
1700    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1701        HAVE_LONG_LONG is not defined.
1703    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1704        bring them up to date and include new features. This patch includes:
1706        - Fixed PH's badly added libz and libbz2 support.
1707        - Fixed a problem with static linking.
1708        - Added pcredemo. [But later removed - see 7 below.]
1709        - Fixed dftables problem and added an option.
1710        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1711            HAVE_LONG_LONG.
1712        - Added readline support for pcretest.
1713        - Added an listing of the option settings after cmake has run.
1715    4.  A user submitted a patch to Makefile that makes it easy to create
1716        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1717        Makefile.am that cause it to include this special target, without
1718        affecting anything else. Note that the same mingw target plus all
1719        the other distribution libraries and programs are now supported
1720        when configuring with CMake (see 6 below) instead of with
1721        Configure/Make.
1723    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1724        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1725        exported in the Windows port". It has not yet been confirmed that the patch
1726        solves the problem, but it does no harm.
1728    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1729        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1730        with CMake, and also correct the comment about stack recursion.
1732    7.  Remove the automatic building of pcredemo from the ./configure system and
1733        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1734        of a program that users should build themselves after PCRE is installed, so
1735        building it automatically is not really right. What is more, it gave
1736        trouble in some build environments.
1738    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1741    Version 7.5 10-Jan-08
1742  ---------------------  ---------------------
1744  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1745      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1747  2.  Negative specials like \S did not work in character classes in UTF-8 mode.  2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1748      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1749      included.      included.
1751  3.  The same bug as (2) above applied to negated POSIX classes such as  3.  The same bug as (2) above applied to negated POSIX classes such as
1752      [:^space:].      [:^space:].
1754  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1755      defined or documented. It seems to have been a typo for PCRE_STATIC, so      defined or documented. It seems to have been a typo for PCRE_STATIC, so
1756      I have changed it.      I have changed it.
1758  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1759      first named subpattern) and a construct such as (?&a) would reference the      first named subpattern) and a construct such as (?&a) would reference the
1760      first named subpattern whose name started with "a" (in other words, the      first named subpattern whose name started with "a" (in other words, the
1761      length check was missing). Both these problems are fixed. "Subpattern name      length check was missing). Both these problems are fixed. "Subpattern name
1762      expected" is now given for (?&) (a zero-length name), and this patch also      expected" is now given for (?&) (a zero-length name), and this patch also
1763      makes it give the same error for \k'' (previously it complained that that      makes it give the same error for \k'' (previously it complained that that
1764      was a reference to a non-existent subpattern).      was a reference to a non-existent subpattern).
1766  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1767      this is right because (?- can be followed by option settings as well as by      this is right because (?- can be followed by option settings as well as by
1768      digits. I have, however, made the messages clearer.      digits. I have, however, made the messages clearer.
1770  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1771      than the number used in the conditional) now cause a compile-time error.      than the number used in the conditional) now cause a compile-time error.
1772      This is actually not compatible with Perl, which accepts such patterns, but      This is actually not compatible with Perl, which accepts such patterns, but
1773      treats the conditional as always being FALSE (as PCRE used to), but it      treats the conditional as always being FALSE (as PCRE used to), but it
1774      seems to me that giving a diagnostic is better.      seems to me that giving a diagnostic is better.
1776  8.  Change "alphameric" to the more common word "alphanumeric" in comments  8.  Change "alphameric" to the more common word "alphanumeric" in comments
1777      and messages.      and messages.
1779  9.  Fix two occurrences of "backslash" in comments that should have been  9.  Fix two occurrences of "backslash" in comments that should have been
1780      "backspace".      "backspace".
1782  10. Remove two redundant lines of code that can never be obeyed (their function  10. Remove two redundant lines of code that can never be obeyed (their function
1783      was moved elsewhere).      was moved elsewhere).
1785  11. The program that makes PCRE's Unicode character property table had a bug  11. The program that makes PCRE's Unicode character property table had a bug
1786      which caused it to generate incorrect table entries for sequences of      which caused it to generate incorrect table entries for sequences of
1787      characters that have the same character type, but are in different scripts.      characters that have the same character type, but are in different scripts.
1788      It amalgamated them into a single range, with the script of the first of      It amalgamated them into a single range, with the script of the first of
1789      them. In other words, some characters were in the wrong script. There were      them. In other words, some characters were in the wrong script. There were
1790      thirteen such cases, affecting characters in the following ranges:      thirteen such cases, affecting characters in the following ranges:
1792        U+002b0 - U+002c1        U+002b0 - U+002c1
1793        U+0060c - U+0060d        U+0060c - U+0060d
1794        U+0061e - U+00612        U+0061e - U+00612
1795        U+0064b - U+0065e        U+0064b - U+0065e
1796        U+0074d - U+0076d        U+0074d - U+0076d
1797        U+01800 - U+01805        U+01800 - U+01805
# Line 65  Version 7.5 12-Nov-07 Line 1802  Version 7.5 12-Nov-07
1802        U+03260 - U+0327f        U+03260 - U+0327f
1803        U+0fb46 - U+0fbb1        U+0fb46 - U+0fbb1
1804        U+10450 - U+1049d        U+10450 - U+1049d
1806  12. The -o option (show only the matching part of a line) for pcregrep was not  12. The -o option (show only the matching part of a line) for pcregrep was not
1807      compatible with GNU grep in that, if there was more than one match in a      compatible with GNU grep in that, if there was more than one match in a
1808      line, it showed only the first of them. It now behaves in the same way as      line, it showed only the first of them. It now behaves in the same way as
1809      GNU grep.      GNU grep.
1811  13. If the -o and -v options were combined for pcregrep, it printed a blank  13. If the -o and -v options were combined for pcregrep, it printed a blank
1812      line for every non-matching line. GNU grep prints nothing, and pcregrep now      line for every non-matching line. GNU grep prints nothing, and pcregrep now
1813      does the same. The return code can be used to tell if there were any      does the same. The return code can be used to tell if there were any
1814      non-matching lines.      non-matching lines.
1816  14. The pattern (?=something)(?R) was not being diagnosed as a potentially  14. Added --file-offsets and --line-offsets to pcregrep.
1818    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1819      infinitely looping recursion. The bug was that positive lookaheads were not      infinitely looping recursion. The bug was that positive lookaheads were not
1820      being skipped when checking for a possible empty match (negative lookaheads      being skipped when checking for a possible empty match (negative lookaheads
1821      and both kinds of lookbehind were skipped).      and both kinds of lookbehind were skipped).
1823    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1824        inclusion of <windows.h> to before rather than after the definition of
1825        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1827    17. Specifying a possessive quantifier with a specific limit for a Unicode
1828        character property caused pcre_compile() to compile bad code, which led at
1829        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1830        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1831        caused the error; without that there was no problem.
1833    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1835    19. Added --enable-pcretest-libreadline.
1837    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1838        RE::GlobalReplace(). As a result, the number of replacements returned was
1839        double what it should be. I removed one of the increments, but Craig sent a
1840        later patch that removed the other one (the right fix) and added unit tests
1841        that check the return values (which was not done before).
1843    21. Several CMake things:
1845        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1846            the names libpcre and libpcreposix, not just pcre and pcreposix.
1848        (2) The above change means that pcretest and pcregrep are now correctly
1849            linked with the newly-built libraries, not previously installed ones.
1853    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1854        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1855        UTF-8 newline character). The key issue is that the pattern starts .*;
1856        this means that the match must be either at the beginning, or after a
1857        newline. The bug was in the code for advancing after a failed match and
1858        checking that the new position followed a newline. It was not taking
1859        account of UTF-8 characters correctly.
1861    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1862        character classes. PCRE was not treating the sequence [:...:] as a
1863        character class unless the ... were all letters. Perl, however, seems to
1864        allow any characters between [: and :], though of course it rejects as
1865        unknown any "names" that contain non-letters, because all the known class
1866        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1867        for example, whereas PCRE did not - it did not recognize a POSIX character
1868        class. This seemed a bit dangerous, so the code has been changed to be
1869        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1870        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1871        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1872        Perl does, and where it didn't before.
1874    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1875        Windows environments %n is disabled by default.
1878  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07

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