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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 05-June-07  Version 8.35-RC1 xx-xxxx-201x
5    -----------------------------
7    1.  A new flag is set, when property checks are present in an XCLASS.
8        When this flag is not set, PCRE can perform certain optimizations
9        such as studying these XCLASS-es.
12    Version 8.34 15-December-2013
13    -----------------------------
15    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
16        executable memory. Patch inspired by Carsten Klein.
18    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
19        this macro is never tested and has no effect, because the work to support
20        coverage involves only compiling and linking options and special targets in
21        the Makefile. The comment in config.h implied that defining the macro would
22        enable coverage support, which is totally false. There was also support for
23        setting this macro in the CMake files (my fault, I just copied it from
24        configure). SUPPORT_GCOV has now been removed.
26    3.  Make a small performance improvement in strlen16() and strlen32() in
27        pcretest.
29    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
30        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
31        these cases). There was also one in pcretest.c.
33    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
35    6.  In UTF mode, the code for checking whether a group could match an empty
36        string (which is used for indefinitely repeated groups to allow for
37        breaking an infinite loop) was broken when the group contained a repeated
38        negated single-character class with a character that occupied more than one
39        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
40        UTF-8 mode). The effect was undefined: the group might or might not be
41        deemed as matching an empty string, or the program might have crashed.
43    7.  The code for checking whether a group could match an empty string was not
44        recognizing that \h, \H, \v, \V, and \R must match a character.
46    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
47        an empty string. If it can, pcretest shows this in its information output.
49    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
50        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
51        matched by pcre_exec() without using JIT:
53        (a) If the rest of the pattern did not match after a maximal run of
54            grapheme clusters, the code for backing up to try with fewer of them
55            did not always back up over a full grapheme when characters that do not
56            have the modifier quality were involved, e.g. Hangul syllables.
58        (b) If the match point in a subject started with modifier character, and
59            there was no match, the code could incorrectly back up beyond the match
60            point, and potentially beyond the first character in the subject,
61            leading to a segfault or an incorrect match result.
63    10. A conditional group with an assertion condition could lead to PCRE
64        recording an incorrect first data item for a match if no other first data
65        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
66        first data item, and therefore matched "ca" after "c" instead of at the
67        start.
69    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
70        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
72    12. The source of pcregrep now includes z/OS-specific code so that it can be
73        compiled for z/OS as part of the special z/OS distribution.
75    13. Added the -T and -TM options to pcretest.
77    14. The code in pcre_compile.c for creating the table of named capturing groups
78        has been refactored. Instead of creating the table dynamically during the
79        actual compiling pass, the information is remembered during the pre-compile
80        pass (on the stack unless there are more than 20 named groups, in which
81        case malloc() is used) and the whole table is created before the actual
82        compile happens. This has simplified the code (it is now nearly 150 lines
83        shorter) and prepared the way for better handling of references to groups
84        with duplicate names.
86    15. A back reference to a named subpattern when there is more than one of the
87        same name now checks them in the order in which they appear in the pattern.
88        The first one that is set is used for the reference. Previously only the
89        first one was inspected. This change makes PCRE more compatible with Perl.
91    16. Unicode character properties were updated from Unicode 6.3.0.
93    17. The compile-time code for auto-possessification has been refactored, based
94        on a patch by Zoltan Herczeg. It now happens after instead of during
95        compilation. The code is cleaner, and more cases are handled. The option
96        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
97        options in pcretest are provided to set it. It can also be set by
98        (*NO_AUTO_POSSESS) at the start of a pattern.
100    18. The character VT has been added to the default ("C" locale) set of
101        characters that match \s and are generally treated as white space,
102        following this same change in Perl 5.18. There is now no difference between
103        "Perl space" and "POSIX space". Whether VT is treated as white space in
104        other locales depends on the locale.
106    19. The code for checking named groups as conditions, either for being set or
107        for being recursed, has been refactored (this is related to 14 and 15
108        above). Processing unduplicated named groups should now be as fast at
109        numerical groups, and processing duplicated groups should be faster than
110        before.
112    20. Two patches to the CMake build system, by Alexander Barkov:
114          (1) Replace the "source" command by "." in CMakeLists.txt because
115              "source" is a bash-ism.
117          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
118              without these the CMake build does not work on Solaris.
120    21. Perl has changed its handling of \8 and \9. If there is no previously
121        encountered capturing group of those numbers, they are treated as the
122        literal characters 8 and 9 instead of a binary zero followed by the
123        literals. PCRE now does the same.
125    22. Following Perl, added \o{} to specify codepoints in octal, making it
126        possible to specify values greater than 0777 and also making them
127        unambiguous.
129    23. Perl now gives an error for missing closing braces after \x{... instead of
130        treating the string as literal. PCRE now does the same.
132    24. RunTest used to grumble if an inappropriate test was selected explicitly,
133        but just skip it when running all tests. This make it awkward to run ranges
134        of tests when one of them was inappropriate. Now it just skips any
135        inappropriate tests, as it always did when running all tests.
137    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
138        character types such as \d or \w, too many callouts were inserted, and the
139        data that they returned was rubbish.
141    26. In UCP mode, \s was not matching two of the characters that Perl matches,
142        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
143        were matched by \h. The code has now been refactored so that the lists of
144        the horizontal and vertical whitespace characters used for \h and \v (which
145        are defined only in one place) are now also used for \s.
147    27. Add JIT support for the 64 bit TileGX architecture.
148        Patch by Jiong Wang (Tilera Corporation).
150    28. Possessive quantifiers for classes (both explicit and automatically
151        generated) now use special opcodes instead of wrapping in ONCE brackets.
153    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
154        (because it's meaningless), this was not happening when PCRE_CASELESS was
155        set. Not wrong, but inefficient.
157    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
158        properties for \w, \d, etc) is present in a test regex. Otherwise if the
159        test contains no characters greater than 255, Perl doesn't realise it
160        should be using Unicode semantics.
162    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
163        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
164        does in Unicode mode.
166    32. Added the "forbid" facility to pcretest so that putting tests into the
167        wrong test files can sometimes be quickly detected.
169    33. There is now a limit (default 250) on the depth of nesting of parentheses.
170        This limit is imposed to control the amount of system stack used at compile
171        time. It can be changed at build time by --with-parens-nest-limit=xxx or
172        the equivalent in CMake.
174    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
175        errors. Perl warns for these when in warning mode, but PCRE has no facility
176        for giving warnings.
178    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
179        However, this was not working for (?!) because it is optimized to (*FAIL),
180        for which PCRE does not allow quantifiers. The optimization is now disabled
181        when a quantifier follows (?!). I can't see any use for this, but it makes
182        things uniform.
184    36. Perl no longer allows group names to start with digits, so I have made this
185        change also in PCRE. It simplifies the code a bit.
187    37. In extended mode, Perl ignores spaces before a + that indicates a
188        possessive quantifier. PCRE allowed a space before the quantifier, but not
189        before the possessive +. It now does.
191    38. The use of \K (reset reported match start) within a repeated possessive
192        group such as (a\Kb)*+ was not working.
194    40. Document that the same character tables must be used at compile time and
195        run time, and that the facility to pass tables to pcre_exec() and
196        pcre_dfa_exec() is for use only with saved/restored patterns.
198    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
199        features for Builds with MSVC:
201        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
202           builds). The .rc files can be used to set FileDescription and many other
203           attributes.
205        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
206           This allows higher-level build scripts which want .pdb files to avoid
207           hard-coding the exact files needed."
209    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
210        mean "start of word" and "end of word", respectively, as a transition aid.
212    43. A minimizing repeat of a class containing codepoints greater than 255 in
213        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
214        compiled to use the heap for recursion.
216    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
217        is configured.
220    Version 8.33 28-May-2013
221    ------------------------
223    1.  Added 'U' to some constants that are compared to unsigned integers, to
224        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
225        variables that are added to signed variables, to ensure the result is
226        signed and can be negated.
228    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
229        CMake config files.
231    3.  Revise the creation of config.h.generic so that all boolean macros are
232        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
233        overriding via -D on the command line possible.
235    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
236        to unsigned int is reported to make a quite noticeable speed difference in
237        a specific Windows environment. Testing on Linux did also appear to show
238        some benefit (and it is clearly not harmful). Also fixed the definition of
239        Xop which should be unsigned.
241    5.  Related to (4), changing the definition of the intermediate variable cc
242        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
243        improvements.
245    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
246        unnecessary spaces.
248    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
249        and later.
251    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
253    9.  Optimizing fast_forward_start_bits in JIT.
255    10. Adding support for callouts in JIT, and fixing some issues revealed
256        during this work. Namely:
258        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
260        (b) Minimum length was not checked before the matching is started.
262    11. The value of capture_last that is passed to callouts was incorrect in some
263        cases when there was a capture on one path that was subsequently abandoned
264        after a backtrack. Also, the capture_last value is now reset after a
265        recursion, since all captures are also reset in this case.
267    12. The interpreter no longer returns the "too many substrings" error in the
268        case when an overflowing capture is in a branch that is subsequently
269        abandoned after a backtrack.
271    13. In the pathological case when an offset vector of size 2 is used, pcretest
272        now prints out the matched string after a yield of 0 or 1.
274    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
275        Only supported by the JIT compiler at the moment.
277    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
279    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
280        offset of the starting point of the matching process, provided the offsets
281        vector is large enough.
283    17. The \A escape now records a lookbehind value of 1, though its execution
284        does not actually inspect the previous character. This is to ensure that,
285        in partial multi-segment matching, at least one character from the old
286        segment is retained when a new segment is processed. Otherwise, if there
287        are no lookbehinds in the pattern, \A might match incorrectly at the start
288        of a new segment.
290    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
292    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
293        gives some modest performance improvement in 8-bit mode.
295    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
296        be expressed in certain programming languages using Universal Character
297        Names.
299    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
300        which points out that "non characters" are not "characters that may not
301        appear in Unicode strings" but rather "characters that are reserved for
302        internal use and have only local meaning".
304    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
305        there was a conditional group that depended on an assertion, if the
306        assertion was false, the callout that immediately followed the alternation
307        in the condition was skipped when pcre_exec() was used for matching.
309    23. Allow an explicit callout to be inserted before an assertion that is the
310        condition for a conditional group, for compatibility with automatic
311        callouts, which always insert a callout at this point.
313    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
314        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
316    25. (*PRUNE) is now supported by the JIT compiler.
318    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
320    27. Fix the case where there are two or more SKIPs with arguments that may be
321        ignored.
323    28. (*SKIP) is now supported by the JIT compiler.
325    29. (*THEN) is now supported by the JIT compiler.
327    30. Update RunTest with additional test selector options.
329    31. The way PCRE handles backtracking verbs has been changed in two ways.
331        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
332        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
333        backtracking. In some cases this makes it more Perl-compatible, but Perl's
334        rather obscure rules do not always do the same thing.
336        (2) Previously, backtracking verbs were confined within assertions. This is
337        no longer the case for positive assertions, except for (*ACCEPT). Again,
338        this sometimes improves Perl compatibility, and sometimes does not.
340    32. A number of tests that were in test 2 because Perl did things differently
341        have been moved to test 1, because either Perl or PCRE has changed, and
342        these tests are now compatible.
344    32. Backtracking control verbs are now handled in the same way in JIT and
345        interpreter.
347    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
348        contained a forward subroutine reference caused a compile error.
350    34. Auto-detect and optimize limited repetitions in JIT.
352    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
353        blocking (*UTF) etc.
355    36. In the interpreter, maximizing pattern repetitions for characters and
356        character types now use tail recursion, which reduces stack usage.
358    37. The value of the max lookbehind was not correctly preserved if a compiled
359        and saved regex was reloaded on a host of different endianness.
361    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
362        of the compiled pattern block, expand the flags field from 16 to 32 bits
363        because it was almost full.
365    39. Try madvise first before posix_madvise.
367    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
368        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
369        original change locked out all matches of empty strings. This has been
370        changed so that one match of an empty string per line is recognized.
371        Subsequent searches on the same line (for colouring or for --only-matching,
372        for example) do not recognize empty strings.
374    41. Applied a user patch to fix a number of spelling mistakes in comments.
376    42. Data lines longer than 65536 caused pcretest to crash.
378    43. Clarified the data type for length and startoffset arguments for pcre_exec
379        and pcre_dfa_exec in the function-specific man pages, where they were
380        explicitly stated to be in bytes, never having been updated. I also added
381        some clarification to the pcreapi man page.
383    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
384        a segmentation fault.
387    Version 8.32 30-November-2012
388    -----------------------------
390    1.  Improved JIT compiler optimizations for first character search and single
391        character iterators.
393    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
394        Patch by Daniel Richard G.
396    3.  Single character iterator optimizations in the JIT compiler.
398    4.  Improved JIT compiler optimizations for character ranges.
400    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
401        Reported by Giuseppe D'Angelo.
403    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
404        of a line, was being set incorrectly in cases where .* appeared inside
405        atomic brackets at the start of a pattern, or where there was a subsequent
406        *PRUNE or *SKIP.
408    7.  Improved instruction cache flush for POWER/PowerPC.
409        Patch by Daniel Richard G.
411    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
412        grep:
414        (a) There is now no limit to the number of patterns to be matched.
416        (b) An error is given if a pattern is too long.
418        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
419            are now supported.
421        (d) --exclude-from and --include-from (multiple use) have been added.
423        (e) Exclusions and inclusions now apply to all files and directories, not
424            just to those obtained from scanning a directory recursively.
426        (f) Multiple uses of -f and --file-list are now supported.
428        (g) In a Windows environment, the default for -d has been changed from
429            "read" (the GNU grep default) to "skip", because otherwise the presence
430            of a directory in the file list provokes an error.
432        (h) The documentation has been revised and clarified in places.
434    9.  Improve the matching speed of capturing brackets.
436    10. Changed the meaning of \X so that it now matches a Unicode extended
437        grapheme cluster.
439    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
440        out POSIX threads when JIT support is configured.
442    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
444    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
445        structure could go wrong in environments where size_t is not the same size
446        as int.
448    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
449        set.
451    15. The EBCDIC support had decayed; later updates to the code had included
452        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
453        general tidy up of EBCDIC-related issues, and the documentation was also
454        not quite right. There is now a test that can be run on ASCII systems to
455        check some of the EBCDIC-related things (but is it not a full test).
457    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
458        in a small tidy to the code.
460    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
462    18. If the --only-matching (-o) option in pcregrep is specified multiple
463        times, each one causes appropriate output. For example, -o1 -o2 outputs the
464        substrings matched by the 1st and 2nd capturing parentheses. A separating
465        string can be specified by --om-separator (default empty).
467    19. Improving the first n character searches.
469    20. Turn case lists for horizontal and vertical white space into macros so that
470        they are defined only once.
472    21. This set of changes together give more compatible Unicode case-folding
473        behaviour for characters that have more than one other case when UCP
474        support is available.
476        (a) The Unicode property table now has offsets into a new table of sets of
477            three or more characters that are case-equivalent. The MultiStage2.py
478            script that generates these tables (the pcre_ucd.c file) now scans
479            CaseFolding.txt instead of UnicodeData.txt for character case
480            information.
482        (b) The code for adding characters or ranges of characters to a character
483            class has been abstracted into a generalized function that also handles
484            case-independence. In UTF-mode with UCP support, this uses the new data
485            to handle characters with more than one other case.
487        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
488            whose other case is greater than 256 are now correctly matched
489            caselessly. Previously, the high codepoint matched the low one, but not
490            vice versa.
492        (d) The processing of \h, \H, \v, and \ in character classes now makes use
493            of the new class addition function, using character lists defined as
494            macros alongside the case definitions of 20 above.
496        (e) Caseless back references now work with characters that have more than
497            one other case.
499        (f) General caseless matching of characters with more than one other case
500            is supported.
502    22. Unicode character properties were updated from Unicode 6.2.0
504    23. Improved CMake support under Windows. Patch by Daniel Richard G.
506    24. Add support for 32-bit character strings, and UTF-32
508    25. Major JIT compiler update (code refactoring and bugfixing).
509        Experimental Sparc 32 support is added.
511    26. Applied a modified version of Daniel Richard G's patch to create
512        pcre.h.generic and config.h.generic by "make" instead of in the
513        PrepareRelease script.
515    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
516        pcre_compile.c when checking for a zero character.
518    28. Introducing a native interface for JIT. Through this interface, the compiled
519        machine code can be directly executed. The purpose of this interface is to
520        provide fast pattern matching, so several sanity checks are not performed.
521        However, feature tests are still performed. The new interface provides
522        1.4x speedup compared to the old one.
524    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
525        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
526        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
528    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
529        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
530        the "old" RFC 2279). Instead, it ended up passing a negative length to
531        pcre_exec().
533    31. Add support for GCC's visibility feature to hide internal functions.
535    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
536        "unknown -C option" after outputting 0 or 1.
538    33. There is now support for generating a code coverage report for the test
539        suite in environments where gcc is the compiler and lcov is installed. This
540        is mainly for the benefit of the developers.
542    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
543        unaddressable using valgrind annotations, allowing valgrind to detect
544        invalid memory accesses. This is mainly for the benefit of the developers.
546    25. (*UTF) can now be used to start a pattern in any of the three libraries.
548    26. Give configure error if --enable-cpp but no C++ compiler found.
551    Version 8.31 06-July-2012
552    -------------------------
554    1.  Fixing a wrong JIT test case and some compiler warnings.
556    2.  Removed a bashism from the RunTest script.
558    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
559        to unsigned type, result still unsigned" that was given by an MS compiler
560        on encountering the code "-sizeof(xxx)".
562    4.  Partial matching support is added to the JIT compiler.
564    5.  Fixed several bugs concerned with partial matching of items that consist
565        of more than one character:
567        (a) /^(..)\1/ did not partially match "aba" because checking references was
568            done on an "all or nothing" basis. This also applied to repeated
569            references.
571        (b) \R did not give a hard partial match if \r was found at the end of the
572            subject.
574        (c) \X did not give a hard partial match after matching one or more
575            characters at the end of the subject.
577        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
578            a partial match for the string "\r".
580        (e) When newline was set to CRLF, the metacharacter "." did not recognize
581            a partial match for a CR character at the end of the subject string.
583    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
584        running pcretest, the text "(JIT)" added to the output whenever JIT is
585        actually used to run the match.
587    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
588        or /S+[+] with a digit between 1 and 7.
590    8.  OP_NOT now supports any UTF character not just single-byte ones.
592    9.  (*MARK) control verb is now supported by the JIT compiler.
594    10. The command "./RunTest list" lists the available tests without actually
595        running any of them. (Because I keep forgetting what they all are.)
599    12. Applied a (slightly modified) user-supplied patch that improves performance
600        when the heap is used for recursion (compiled with --disable-stack-for-
601        recursion). Instead of malloc and free for each heap frame each time a
602        logical recursion happens, frames are retained on a chain and re-used where
603        possible. This sometimes gives as much as 30% improvement.
605    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
606        call.
608    14. As documented, (*COMMIT) is now confined to within a positive assertion.
610    15. It is now possible to link pcretest with libedit as an alternative to
611        libreadline.
613    16. (*COMMIT) control verb is now supported by the JIT compiler.
615    17. The Unicode data tables have been updated to Unicode 6.1.0.
617    18. Added --file-list option to pcregrep.
619    19. Added binary file support to pcregrep, including the -a, --binary-files,
620        -I, and --text options.
622    20. The madvise function is renamed for posix_madvise for QNX compatibility
623        reasons. Fixed by Giuseppe D'Angelo.
625    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
627    22. Changed the option for creating symbolic links for 16-bit man pages from
628        -s to -sf so that re-installing does not cause issues.
630    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
632    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
633        matches in certain environments (the workspace was not being correctly
634        retained). Also added to pcre_dfa_exec() a simple plausibility check on
635        some of the workspace data at the beginning of a restart.
637    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
638        was not doing so when it should - probably a typo introduced by SVN 528
639        (change 8.10/14).
641    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
642        \w+ when the character tables indicated that \x{c4} was a word character.
643        There were several related cases, all because the tests for doing a table
644        lookup were testing for characters less than 127 instead of 255.
646    27. If a pattern contains capturing parentheses that are not used in a match,
647        their slots in the ovector are set to -1. For those that are higher than
648        any matched groups, this happens at the end of processing. In the case when
649        there were back references that the ovector was too small to contain
650        (causing temporary malloc'd memory to be used during matching), and the
651        highest capturing number was not used, memory off the end of the ovector
652        was incorrectly being set to -1. (It was using the size of the temporary
653        memory instead of the true size.)
655    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
656        ovector size, it uses memory at the end of the block that it has got.
658    29. Check for an overlong MARK name and give an error at compile time. The
659        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
661    30. JIT compiler update.
663    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
664        Rill for the patch.
666    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
668    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
670    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
671        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
672        was enabled.
674    35. Improve JIT code generation for greedy plus quantifier.
676    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
677        1 to "aa" instead of to an empty string. The bug affected repeated groups
678        that could potentially match an empty string.
680    37. Optimizing single character iterators in JIT.
682    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
683        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
684        codepoints that are too big for the mode are faulted, and in a UTF mode,
685        disallowed codepoints are also faulted.
687    39. If PCRE was compiled with UTF support, in three places in the DFA
688        matcher there was code that should only have been obeyed in UTF mode, but
689        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
690        processing when bytes with values greater than 127 were present. In 16-bit
691        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
692        both cases the values are those that cannot be the first data item in a UTF
693        character. The three items that might have provoked this were recursions,
694        possessively repeated groups, and atomic groups.
696    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
697        and pcregrep, because some OS require shared objects to be explicitly
698        passed to ld, causing the link step to fail if they are not.
700    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
701        mode, patterns that started with \h* or \R* might be incorrectly matched.
704    Version 8.30 04-February-2012
705    -----------------------------
707    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
708        name is defined in ctype.h.
710    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
711        only in quite long subpatterns.
713    3.  Removed the function pcre_info(), which has been obsolete and deprecated
714        since it was replaced by pcre_fullinfo() in February 2000.
716    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
717        match a (*MARK), and the match failed at the start of the subject, a
718        reference to memory before the start of the subject could occur. This bug
719        was introduced by fix 17 of release 8.21.
721    5.  A reference to an unset group with zero minimum repetition was giving
722        totally wrong answers (in non-JavaScript-compatibility mode). For example,
723        /(another)?(\1?)test/ matched against "hello world test". This bug was
724        introduced in release 8.13.
726    6.  Add support for 16-bit character strings (a large amount of work involving
727        many changes and refactorings).
729    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
730        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
731        from a file.
733    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
734        rounding is not applied in this particular case).
736    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
737        if they appear, or are escaped, in patterns.
739    10. Get rid of a number of -Wunused-but-set-variable warnings.
741    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
742        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
743        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
744        also returns the mark "x". This bug applied to capturing parentheses,
745        non-capturing parentheses, and atomic parentheses. It also applied to some
746        assertions.
748    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
749        information out of configure.ac instead of relying on pcre.h.generic, which
750        is not stored in the repository.
752    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
753        -lreadline.
755    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
757    15. Applied Graycode's patch to put the top-level frame on the stack rather
758        than the heap when not using the stack for recursion. This gives a
759        performance improvement in many cases when recursion is not deep.
761    16. Experimental code added to "pcretest -C" to output the stack frame size.
764    Version 8.21 12-Dec-2011
765    ------------------------
767    1.  Updating the JIT compiler.
769    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
770        are added as well.
772    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
773        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
774        calling _pcre_jit_exec. Some extra comments are added.
776    4.  (*MARK) settings inside atomic groups that do not contain any capturing
777        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
778        was introduced by change 18 for 8.20.
780    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
781        ECMA-262 standard.
783    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
784        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
785        This bug was probably introduced by change 9 of 8.13.
787    7.  While fixing 6 above, I noticed that a number of other items were being
788        incorrectly rejected as "not fixed length". This arose partly because newer
789        opcodes had not been added to the fixed-length checking code. I have (a)
790        corrected the bug and added tests for these items, and (b) arranged for an
791        error to occur if an unknown opcode is encountered while checking for fixed
792        length instead of just assuming "not fixed length". The items that were
793        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
794        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
795        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
797    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
798        being incorrectly compiled and would have given unpredicatble results.
800    9.  A possessively repeated subpattern with minimum repeat count greater than
801        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
802        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
803        the first (A) could occur when it should not.
805    10. Add a cast and remove a redundant test from the code.
807    11. JIT should use pcre_malloc/pcre_free for allocation.
809    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
810        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
811        is anything other than /usr, -L is still shown).
813    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
815    14. Perl does not support \N without a following name in a [] class; PCRE now
816        also gives an error.
818    15. If a forward reference was repeated with an upper limit of around 2000,
819        it caused the error "internal error: overran compiling workspace". The
820        maximum number of forward references (including repeats) was limited by the
821        internal workspace, and dependent on the LINK_SIZE. The code has been
822        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
823        the default depends on LINK_SIZE. There is a new upper limit (for safety)
824        of around 200,000 forward references. While doing this, I also speeded up
825        the filling in of repeated forward references.
827    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
828        incorrectly expecting the subject to contain another "a" after the start.
830    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
831        in the match, the SKIP should be ignored. This was not happening; instead
832        the SKIP was being treated as NOMATCH. For patterns such as
833        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
834        tested.
836    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
837        now much more compatible with Perl, in particular in cases where the result
838        is a non-match for a non-anchored pattern. For example, if
839        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
840        "m", where previously it did not return a name. A side effect of this
841        change is that for partial matches, the last encountered mark name is
842        returned, as for non matches. A number of tests that were previously not
843        Perl-compatible have been moved into the Perl-compatible test files. The
844        refactoring has had the pleasing side effect of removing one argument from
845        the match() function, thus reducing its stack requirements.
847    19. If the /S+ option was used in pcretest to study a pattern using JIT,
848        subsequent uses of /S (without +) incorrectly behaved like /S+.
850    21. Retrieve executable code size support for the JIT compiler and fixing
851        some warnings.
853    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
854        not work when the shorter character appeared right at the end of the
855        subject string.
857    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
858        systems.
860    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
861        output it when the /M option is used in pcretest.
863    25. The CheckMan script was not being included in the distribution. Also, added
864        an explicit "perl" to run Perl scripts from the PrepareRelease script
865        because this is reportedly needed in Windows.
867    26. If study data was being save in a file and studying had not found a set of
868        "starts with" bytes for the pattern, the data written to the file (though
869        never used) was taken from uninitialized memory and so caused valgrind to
870        complain.
872    27. Updated RunTest.bat as provided by Sheri Pierce.
874    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
876    29. Computation of memory usage for the table of capturing group names was
877        giving an unnecessarily large value.
880    Version 8.20 21-Oct-2011
881    ------------------------
883    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
884        a POSIX class. After further experiments with Perl, which convinced me that
885        Perl has bugs and confusions, a closing square bracket is no longer allowed
886        in a POSIX name. This bug also affected patterns with classes that started
887        with full stops.
889    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
890        captured substring, but while checking the failing first alternative,
891        substring 1 is temporarily captured. If the output vector supplied to
892        pcre_exec() was not big enough for this capture, the yield of the function
893        was still zero ("insufficient space for captured substrings"). This cannot
894        be totally fixed without adding another stack variable, which seems a lot
895        of expense for a edge case. However, I have improved the situation in cases
896        such as /(a)(b)x|abc/ matched against "abc", where the return code
897        indicates that fewer than the maximum number of slots in the ovector have
898        been set.
900    3.  Related to (2) above: when there are more back references in a pattern than
901        slots in the output vector, pcre_exec() uses temporary memory during
902        matching, and copies in the captures as far as possible afterwards. It was
903        using the entire output vector, but this conflicts with the specification
904        that only 2/3 is used for passing back captured substrings. Now it uses
905        only the first 2/3, for compatibility. This is, of course, another edge
906        case.
908    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
909        main code base, and can be used by building with --enable-jit. When this is
910        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
911        runtime --no-jit option is given.
913    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
914        ovector, the return from the function was zero, implying that there were
915        other matches that did not fit. The correct "exactly full" value is now
916        returned.
918    6.  If a subpattern that was called recursively or as a subroutine contained
919        (*PRUNE) or any other control that caused it to give a non-standard return,
920        invalid errors such as "Error -26 (nested recursion at the same subject
921        position)" or even infinite loops could occur.
923    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
924        computing the minimum length on reaching *ACCEPT, and so ended up with the
925        wrong value of 1 rather than 0. Further investigation indicates that
926        computing a minimum subject length in the presence of *ACCEPT is difficult
927        (think back references, subroutine calls), and so I have changed the code
928        so that no minimum is registered for a pattern that contains *ACCEPT.
930    8.  If (*THEN) was present in the first (true) branch of a conditional group,
931        it was not handled as intended. [But see 16 below.]
933    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
934        Sheri Pierce.
936    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
937        the first byte in a match must be "a".
939    11. Change 17 for 8.13 increased the recursion depth for patterns like
940        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
941        pattern contains any instances of (*THEN). If it does not, the old
942        optimizations are restored. It would be nice to do this on a per-group
943        basis, but at the moment that is not feasible.
945    12. In some environments, the output of pcretest -C is CRLF terminated. This
946        broke RunTest's code that checks for the link size. A single white space
947        character after the value is now allowed for.
949    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
950        For "fr", it uses the Windows-specific input and output files.
952    14. If (*THEN) appeared in a group that was called recursively or as a
953        subroutine, it did not work as intended. [But see next item.]
955    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
956        pattern fragments (but not containing any | characters). If A and B are
957        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
958        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
959        D. In other words, Perl considers parentheses that do not contain any |
960        characters to be part of a surrounding alternative, whereas PCRE was
961        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
962        differently. PCRE now behaves in the same way as Perl, except in the case
963        of subroutine/recursion calls such as (?1) which have in any case always
964        been different (but PCRE had them first :-).
966    16. Related to 15 above: Perl does not treat the | in a conditional group as
967        creating alternatives. Such a group is treated in the same way as an
968        ordinary group without any | characters when processing (*THEN). PCRE has
969        been changed to match Perl's behaviour.
971    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
972        RunGrepTest script failed.
974    18. Change 22 for version 13 caused atomic groups to use more stack. This is
975        inevitable for groups that contain captures, but it can lead to a lot of
976        stack use in large patterns. The old behaviour has been restored for atomic
977        groups that do not contain any capturing parentheses.
979    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
980        suppress the check for a minimum subject length at run time. (If it was
981        given to pcre_exec() or pcre_dfa_exec() it did work.)
983    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
984        fail to work when decoding hex characters in data strings in EBCDIC
985        environments.
987    21. It appears that in at least one Mac OS environment, the isxdigit() function
988        is implemented as a macro that evaluates to its argument more than once,
989        contravening the C 90 Standard (I haven't checked a later standard). There
990        was an instance in pcretest which caused it to go wrong when processing
991        \x{...} escapes in subject strings. The has been rewritten to avoid using
992        things like p++ in the argument of isxdigit().
995    Version 8.13 16-Aug-2011
996    ------------------------
998    1.  The Unicode data tables have been updated to Unicode 6.0.0.
1000    2.  Two minor typos in pcre_internal.h have been fixed.
1002    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1003        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1004        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1006    4.  There were a number of related bugs in the code for matching backrefences
1007        caselessly in UTF-8 mode when codes for the characters concerned were
1008        different numbers of bytes. For example, U+023A and U+2C65 are an upper
1009        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1010        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1011        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1012        2-byte code at the end of the subject (it thought there wasn't enough data
1013        left).
1015    5.  Comprehensive information about what went wrong is now returned by
1016        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1017        as the output vector has at least 2 elements. The offset of the start of
1018        the failing character and a reason code are placed in the vector.
1020    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
1021        now returned is for the first byte of the failing character, instead of the
1022        last byte inspected. This is an incompatible change, but I hope it is small
1023        enough not to be a problem. It makes the returned offset consistent with
1024        pcre_exec() and pcre_dfa_exec().
1026    7.  pcretest now gives a text phrase as well as the error number when
1027        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1028        failure, the offset and reason code are output.
1030    8.  When \R was used with a maximizing quantifier it failed to skip backwards
1031        over a \r\n pair if the subsequent match failed. Instead, it just skipped
1032        back over a single character (\n). This seems wrong (because it treated the
1033        two characters as a single entity when going forwards), conflicts with the
1034        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1035        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1036        has been changed.
1038    9.  Some internal refactoring has changed the processing so that the handling
1039        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1040        time (the PCRE_DOTALL option was changed this way some time ago: version
1041        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1042        which was always a bit of a fudge. It also means that there is one less
1043        argument for the match() function, which reduces its stack requirements
1044        slightly. This change also fixes an incompatibility with Perl: the pattern
1045        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1047    10. More internal refactoring has drastically reduced the number of recursive
1048        calls to match() for possessively repeated groups such as (abc)++ when
1049        using pcre_exec().
1051    11. While implementing 10, a number of bugs in the handling of groups were
1052        discovered and fixed:
1054        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1055        (a|)*(?1) gave a compile-time internal error.
1056        ((a|)+)+  did not notice that the outer group could match an empty string.
1057        (^a|^)+   was not marked as anchored.
1058        (.*a|.*)+ was not marked as matching at start or after a newline.
1060    12. Yet more internal refactoring has removed another argument from the match()
1061        function. Special calls to this function are now indicated by setting a
1062        value in a variable in the "match data" data block.
1064    13. Be more explicit in pcre_study() instead of relying on "default" for
1065        opcodes that mean there is no starting character; this means that when new
1066        ones are added and accidentally left out of pcre_study(), testing should
1067        pick them up.
1069    14. The -s option of pcretest has been documented for ages as being an old
1070        synonym of -m (show memory usage). I have changed it to mean "force study
1071        for every regex", that is, assume /S for every regex. This is similar to -i
1072        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1073        using it. It makes it easier to run collections of tests with and without
1074        study enabled, and thereby test pcre_study() more easily. All the standard
1075        tests are now run with and without -s (but some patterns can be marked as
1076        "never study" - see 20 below).
1078    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1079        restoration of the capturing data to the outer values was not happening
1080        correctly.
1082    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1083        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1084        pattern had matched an empty string, and so incorrectly returned a no
1085        match.
1087    17. There was optimizing code for the last branch of non-capturing parentheses,
1088        and also for the obeyed branch of a conditional subexpression, which used
1089        tail recursion to cut down on stack usage. Unfortunately, now that there is
1090        the possibility of (*THEN) occurring in these branches, tail recursion is
1091        no longer possible because the return has to be checked for (*THEN). These
1092        two optimizations have therefore been removed. [But see 8.20/11 above.]
1094    18. If a pattern containing \R was studied, it was assumed that \R always
1095        matched two bytes, thus causing the minimum subject length to be
1096        incorrectly computed because \R can also match just one byte.
1098    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1099        was incorrectly computed.
1101    20. If /S is present twice on a test pattern in pcretest input, it now
1102        *disables* studying, thereby overriding the use of -s on the command line
1103        (see 14 above). This is necessary for one or two tests to keep the output
1104        identical in both cases.
1106    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1107        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1109    22. When an atomic group that contained a capturing parenthesis was
1110        successfully matched, but the branch in which it appeared failed, the
1111        capturing was not being forgotten if a higher numbered group was later
1112        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1113        group 1 to "a", when in fact it should be unset. This applied to multi-
1114        branched capturing and non-capturing groups, repeated or not, and also to
1115        positive assertions (capturing in negative assertions does not happen
1116        in PCRE) and also to nested atomic groups.
1118    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1119        subject after a captured substring, to make it easier to tell which of a
1120        number of identical substrings has been captured.
1122    24. The way atomic groups are processed by pcre_exec() has been changed so that
1123        if they are repeated, backtracking one repetition now resets captured
1124        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1125        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1126        "aaa". Previously, it would have been "a". As part of this code
1127        refactoring, the way recursive calls are handled has also been changed.
1129    25. If an assertion condition captured any substrings, they were not passed
1130        back unless some other capturing happened later. For example, if
1131        (?(?=(a))a) was matched against "a", no capturing was returned.
1133    26. When studying a pattern that contained subroutine calls or assertions,
1134        the code for finding the minimum length of a possible match was handling
1135        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1136        group 1 called group 2 while simultaneously a separate group 2 called group
1137        1). A stack overflow occurred in this case. I have fixed this by limiting
1138        the recursion depth to 10.
1140    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1141        Fortmann. This supports explicit test numbers on the command line, and has
1142        argument validation and error reporting.
1144    28. An instance of \X with an unlimited repeat could fail if at any point the
1145        first character it looked at was a mark character.
1147    29. Some minor code refactoring concerning Unicode properties and scripts
1148        should reduce the stack requirement of match() slightly.
1150    30. Added the '=' option to pcretest to check the setting of unused capturing
1151        slots at the end of the pattern, which are documented as being -1, but are
1152        not included in the return count.
1154    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1155        compiled something random. Now it gives a compile-time error (as does
1156        Perl).
1158    32. A *MARK encountered during the processing of a positive assertion is now
1159        recorded and passed back (compatible with Perl).
1161    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1162        had alternative anchored branches, the search for a second match in a line
1163        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1164        matched the line "0102" twice. The same bug affected patterns that started
1165        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1166        twice.
1168    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1169        does, and because of capturing effects, quantifying parenthesized
1170        assertions may at times be useful. Quantifiers are now allowed for
1171        parenthesized assertions.
1173    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1175    36. \g was being checked for fancy things in a character class, when it should
1176        just be a literal "g".
1178    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1179        appearance of a nested POSIX class supersedes an apparent external class.
1180        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1181        unescaped square brackets may also appear as part of class names. For
1182        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1183        more like Perl. (But see 8.20/1 above.)
1185    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1186        was because it thought it was \N{name}, which is not supported).
1188    39. Add minix to OS list not supporting the -S option in pcretest.
1190    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1191        cannot analyze patterns in sufficient detail to catch mutual recursions
1192        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1193        subgroup is called recursively as a subpattern for a second time at the
1194        same position in the subject string. In previous releases this might have
1195        been caught by the recursion limit, or it might have run out of stack.
1197    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1198        happen only once. PCRE was, however incorrectly giving a compile time error
1199        "recursive call could loop indefinitely" because it cannot analyze the
1200        pattern in sufficient detail. The compile time test no longer happens when
1201        PCRE is compiling a conditional subpattern, but actual runaway loops are
1202        now caught at runtime (see 40 above).
1204    42. It seems that Perl allows any characters other than a closing parenthesis
1205        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1206        has been changed to be the same.
1208    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1209        as not to get warnings when autogen.sh is called. Also changed
1210        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1212    44. To help people who use pcregrep to scan files containing exceedingly long
1213        lines, the following changes have been made:
1215        (a) The default value of the buffer size parameter has been increased from
1216            8K to 20K. (The actual buffer used is three times this size.)
1218        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1219            PCRE is built.
1221        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1222            to be set at run time.
1224        (d) Numerical values in pcregrep options can be followed by K or M, for
1225            example --buffer-size=50K.
1227        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1228            given and the return code is set to 2.
1230    45. Add a pointer to the latest mark to the callout data block.
1232    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1233        partial match of an empty string instead of no match. This was specific to
1234        the use of ".".
1236    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1237        complete match instead of a partial match. This bug was dependent on both
1238        the PCRE_UTF8 and PCRE_DOTALL options being set.
1240    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1241        starting byte set, because \b was not being ignored.
1244    Version 8.12 15-Jan-2011
1245    ------------------------
1247    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1248        checks for such things as part of the documentation building process.
1250    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1251        --match-limit and --recursion-limit options (added for 8.11). In
1252        particular, this made one of the standard tests fail. (The integer value
1253        went into the wrong half of a long int.)
1255    3.  If the --colour option was given to pcregrep with -v (invert match), it
1256        did strange things, either producing crazy output, or crashing. It should,
1257        of course, ignore a request for colour when reporting lines that do not
1258        match.
1260    4.  Another pcregrep bug caused similar problems if --colour was specified with
1261        -M (multiline) and the pattern match finished with a line ending.
1263    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1264        matched in multiline mode, the following line was shown as part of the
1265        match. This seems wrong, so I have changed it.
1267    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1268        the check for further matches in the same line (so they could be coloured)
1269        to overrun the end of the current line. If another match was found, it was
1270        incorrectly shown (and then shown again when found in the next line).
1272    7.  If pcregrep was compiled under Windows, there was a reference to the
1273        function pcregrep_exit() before it was defined. I am assuming this was
1274        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1275        reported by a user. I've moved the definition above the reference.
1278    Version 8.11 10-Dec-2010
1279    ------------------------
1281    1.  (*THEN) was not working properly if there were untried alternatives prior
1282        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1283        backtracked to try for "b" instead of moving to the next alternative branch
1284        at the same level (in this case, to look for "c"). The Perl documentation
1285        is clear that when (*THEN) is backtracked onto, it goes to the "next
1286        alternative in the innermost enclosing group".
1288    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1289        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1290        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1291        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1292        (*THEN).
1294    3.  If \s appeared in a character class, it removed the VT character from
1295        the class, even if it had been included by some previous item, for example
1296        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1297        of \s, but is part of the POSIX "space" class.)
1299    4.  A partial match never returns an empty string (because you can always
1300        match an empty string at the end of the subject); however the checking for
1301        an empty string was starting at the "start of match" point. This has been
1302        changed to the "earliest inspected character" point, because the returned
1303        data for a partial match starts at this character. This means that, for
1304        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1305        (previously it gave "no match").
1307    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1308        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1309        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1310        has an implication that the given string is incomplete (because a partial
1311        match is preferred over a full match). For this reason, these items now
1312        give a partial match in this situation. [Aside: previously, the one case
1313        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1314        match rather than a full match, which was wrong by the old rules, but is
1315        now correct.]
1317    6.  There was a bug in the handling of #-introduced comments, recognized when
1318        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1319        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1320        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1321        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1322        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1323        places in pcre_compile().
1325    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1326        comments when looking ahead for named forward references to subpatterns,
1327        the only newline sequence it recognized was NL. It now handles newlines
1328        according to the set newline convention.
1330    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1331        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1332        cater for a lack of strerror(). These oversights have been fixed.
1334    9.  Added --match-limit and --recursion-limit to pcregrep.
1336    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1338    11. When the -o option was used, pcregrep was setting a return code of 1, even
1339        when matches were found, and --line-buffered was not being honoured.
1341    12. Added an optional parentheses number to the -o and --only-matching options
1342        of pcregrep.
1344    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1345        can match an empty string. The code to do it in pcretest and pcredemo
1346        needed fixing:
1348        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1349            only one byte after an empty string match just before CRLF (this case
1350            just got forgotten; "any" and "anycrlf" were OK).
1352        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1353            mode when an empty string match preceded an ASCII character followed by
1354            a non-ASCII character. (The code for advancing by one character rather
1355            than one byte was nonsense.)
1357        (c) The pcredemo.c sample program did not have any code at all to handle
1358            the cases when CRLF is a valid newline sequence.
1360    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1361        as a starting offset was within the subject string. There is now a new
1362        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1363        negative or greater than the length of the string. In order to test this,
1364        pcretest is extended to allow the setting of negative starting offsets.
1366    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1367        starting offset points to the beginning of a UTF-8 character was
1368        unnecessarily clumsy. I tidied it up.
1370    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1371        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1373    17. Nobody had reported that the --include_dir option, which was added in
1374        release 7.7 should have been called --include-dir (hyphen, not underscore)
1375        for compatibility with GNU grep. I have changed it to --include-dir, but
1376        left --include_dir as an undocumented synonym, and the same for
1377        --exclude-dir, though that is not available in GNU grep, at least as of
1378        release 2.5.4.
1380    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1381        characters from a string of bytes) have been redefined so as not to use
1382        loops, in order to improve performance in some environments. At the same
1383        time, I abstracted some of the common code into auxiliary macros to save
1384        repetition (this should not affect the compiled code).
1386    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1387        compile-time error is now given if \c is not followed by an ASCII
1388        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1389        different, and any byte value is allowed.)
1391    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1392        START_OPTIMIZE option, which is now allowed at compile time - but just
1393        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1394        to pcregrep and other applications that have no direct access to PCRE
1395        options. The new /Y option in pcretest sets this option when calling
1396        pcre_compile().
1398    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1399        back references. Groups containing recursive back references were forced to
1400        be atomic by that change, but in the case of named groups, the amount of
1401        memory required was incorrectly computed, leading to "Failed: internal
1402        error: code overflow". This has been fixed.
1404    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1405        pcretest.c, to avoid build problems in some Borland environments.
1408    Version 8.10 25-Jun-2010
1409    ------------------------
1411    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1412        THEN.
1414    2.  (*ACCEPT) was not working when inside an atomic group.
1416    3.  Inside a character class, \B is treated as a literal by default, but
1417        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1418        causes the error). The code is unchanged, but I tidied the documentation.
1420    4.  Inside a character class, PCRE always treated \R and \X as literals,
1421        whereas Perl faults them if its -w option is set. I have changed PCRE so
1422        that it faults them when PCRE_EXTRA is set.
1424    5.  Added support for \N, which always matches any character other than
1425        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1427    6.  When compiling pcregrep with newer versions of gcc which may have
1428        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1429        declared with attribute warn_unused_result" were given. Just casting the
1430        result to (void) does not stop the warnings; a more elaborate fudge is
1431        needed. I've used a macro to implement this.
1433    7.  Minor change to pcretest.c to avoid a compiler warning.
1435    8.  Added four artifical Unicode properties to help with an option to make
1436        \s etc use properties (see next item). The new properties are: Xan
1437        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1439    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1440        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1441        this option. Modified pcretest to add /W to test this facility. Added
1442        REG_UCP to make it available via the POSIX interface.
1444    10. Added --line-buffered to pcregrep.
1446    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1447        studied, and the match started with a letter with a code point greater than
1448        127 whose first byte was different to the first byte of the other case of
1449        the letter, the other case of this starting letter was not recognized
1450        (#976).
1452    12. If a pattern that was studied started with a repeated Unicode property
1453        test, for example, \p{Nd}+, there was the theoretical possibility of
1454        setting up an incorrect bitmap of starting bytes, but fortunately it could
1455        not have actually happened in practice until change 8 above was made (it
1456        added property types that matched character-matching opcodes).
1458    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1459        possible starting bytes for non-anchored patterns.
1461    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1462        \R, and also a number of cases that involve Unicode properties, both
1463        explicit and implicit when PCRE_UCP is set.
1465    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1466        input, it could crash or give wrong results if characters with values
1467        greater than 0xc0 were present in the subject string. (Detail: it assumed
1468        UTF-8 input when processing these items.)
1470    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1471        size_t is 64-bit (#991).
1473    17. Added a check for running out of memory when PCRE is compiled with
1474        --disable-stack-for-recursion (#990).
1476    18. If the last data line in a file for pcretest does not have a newline on
1477        the end, a newline was missing in the output.
1479    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1480        less than 128) in its various bitmaps. However, there is a facility for
1481        generating tables according to the current locale when PCRE is compiled. It
1482        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1483        characters, are recognized by isspace() and therefore were getting set in
1484        these tables, and indeed these tables seem to approximate to ISO 8859. This
1485        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1486        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1487        which of course cannot start UTF-8 characters. I have changed the code so
1488        that only real ASCII characters (less than 128) and the correct starting
1489        bytes for UTF-8 encodings are set for characters greater than 127 when in
1490        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1491        altogether.)
1493    20. Added the /T option to pcretest so as to be able to run tests with non-
1494        standard character tables, thus making it possible to include the tests
1495        used for 19 above in the standard set of tests.
1497    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1498        reference to a subpattern the other side of a comment that contains an
1499        opening parenthesis caused either an internal compiling error, or a
1500        reference to the wrong subpattern.
1503    Version 8.02 19-Mar-2010
1504    ------------------------
1506    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1508    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1509        configured.
1511    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1512        original author of that file, following a query about its status.
1514    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1515        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1517    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1518        quantifier applied to a forward-referencing subroutine call, could compile
1519        incorrect code or give the error "internal error: previously-checked
1520        referenced subpattern not found".
1522    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1523        variables to point to external functions. For these systems, therefore,
1524        pcre_malloc etc. are now initialized to local functions that call the
1525        relevant global functions.
1527    7.  There were two entries missing in the vectors called coptable and poptable
1528        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1529        I've fixed the data, and added a kludgy way of testing at compile time that
1530        the lengths are correct (equal to the number of opcodes).
1532    8.  Following on from 7, I added a similar kludge to check the length of the
1533        eint vector in pcreposix.c.
1535    9.  Error texts for pcre_compile() are held as one long string to avoid too
1536        much relocation at load time. To find a text, the string is searched,
1537        counting zeros. There was no check for running off the end of the string,
1538        which could happen if a new error number was added without updating the
1539        string.
1541    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1543    11. \K was not working if it appeared in an atomic group or in a group that
1544        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1545        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1546        the assertion is positive, but not if it is negative.
1548    12. Change 11 fortuitously reduced the size of the stack frame used in the
1549        "match()" function of pcre_exec.c by one pointer. Forthcoming
1550        implementation of support for (*MARK) will need an extra pointer on the
1551        stack; I have reserved it now, so that the stack frame size does not
1552        decrease.
1554    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1555        item in branch that calls a recursion is a subroutine call - as in the
1556        second branch in the above example - was incorrectly given the compile-
1557        time error "recursive call could loop indefinitely" because pcre_compile()
1558        was not correctly checking the subroutine for matching a non-empty string.
1560    14. The checks for overrunning compiling workspace could trigger after an
1561        overrun had occurred. This is a "should never occur" error, but it can be
1562        triggered by pathological patterns such as hundreds of nested parentheses.
1563        The checks now trigger 100 bytes before the end of the workspace.
1565    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1568    Version 8.01 19-Jan-2010
1569    ------------------------
1571    1.  If a pattern contained a conditional subpattern with only one branch (in
1572        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1573        computed the wrong minimum data length (which is of course zero for such
1574        subpatterns). This could cause incorrect "no match" results.
1576    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1577        the pattern is reset in the first branch, pcre_compile() failed with
1578        "internal error: code overflow at offset...". This happened only when
1579        the reset was to the original external option setting. (An optimization
1580        abstracts leading options settings into an external setting, which was the
1581        cause of this.)
1583    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1584        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1585        assertion pattern did not match (meaning that the assertion was true), it
1586        was incorrectly treated as false if the SKIP had been reached during the
1587        matching. This also applied to assertions used as conditions.
1589    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1590        assertion subpattern, including such a pattern used as a condition,
1591        unpredictable results occurred, instead of the error return
1594    5.  The C++ GlobalReplace function was not working like Perl for the special
1595        situation when an empty string is matched. It now does the fancy magic
1596        stuff that is necessary.
1598    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1599        removed. (These were left over from very, very early versions of PCRE.)
1601    7.  Some cosmetic changes to the code to make life easier when compiling it
1602        as part of something else:
1604        (a) Change DEBUG to PCRE_DEBUG.
1606        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1607            called "current" as "current_branch", to prevent a collision with the
1608            Linux macro when compiled as a kernel module.
1610        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1611            prevent a collision with the Linux macro when compiled as a kernel
1612            module.
1614    8.  In pcre_compile() there are some checks for integer overflows that used to
1615        cast potentially large values to (double). This has been changed to that
1616        when building, a check for int64_t is made, and if it is found, it is used
1617        instead, thus avoiding the use of floating point arithmetic. (There is no
1618        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1619        double.
1621    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1622        2005 (difference between two addresses compared to an unsigned value).
1624    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1625        custom one, because of the following reported problem in Windows:
1627          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1628              under Win32.
1629          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1630              therefore missing the function definition.
1631          - The compiler thus generates a "C" signature for the test function.
1632          - The linker fails to find the "C" function.
1633          - PCRE fails to configure if asked to do so against libbz2.
1635    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1636        messages were output:
1638          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1639          rerunning libtoolize, to keep the correct libtool macros in-tree.
1640          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1642        I have done both of these things.
1644    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1645        most of the time, it *can* run out if it is given a pattern that contains a
1646        runaway infinite recursion. I updated the discussion in the pcrestack man
1647        page.
1649    13. Now that we have gone to the x.xx style of version numbers, the minor
1650        version may start with zero. Using 08 or 09 is a bad idea because users
1651        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1652        interpreted as invalid octal numbers. I've updated the previous comment in
1653        configure.ac, and also added a check that gives an error if 08 or 09 are
1654        used.
1656    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1657        causing partial matching to fail when the end of the subject matched \W
1658        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1660    15. There were some discrepancies between the declarations in pcre_internal.h
1661        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1662        their definitions. The declarations used "const uschar *" and the
1663        definitions used USPTR. Even though USPTR is normally defined as "const
1664        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1665        reported that: "This difference in casting confuses some C++ compilers, for
1666        example, SunCC recognizes above declarations as different functions and
1667        generates broken code for hbpcre." I have changed the declarations to use
1668        USPTR.
1670    16. GNU libtool is named differently on some systems. The autogen.sh script now
1671        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1672        (FreeBSD).
1674    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1675        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1676        comment: "Figure out how to create a longlong from a string: strtoll and
1677        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1678        instance, but it only takes 2 args instead of 3!"
1680    18. A subtle bug concerned with back references has been fixed by a change of
1681        specification, with a corresponding code fix. A pattern such as
1682        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1683        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1684        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1685        same bug. Such groups have to be quantified to be useful, or contained
1686        inside another quantified group. (If there's no repetition, the reference
1687        can never match.) The problem arises because, having left the group and
1688        moved on to the rest of the pattern, a later failure that backtracks into
1689        the group uses the captured value from the final iteration of the group
1690        rather than the correct earlier one. I have fixed this in PCRE by forcing
1691        any group that contains a reference to itself to be an atomic group; that
1692        is, there cannot be any backtracking into it once it has completed. This is
1693        similar to recursive and subroutine calls.
1696    Version 8.00 19-Oct-09
1697    ----------------------
1699    1.  The table for translating pcre_compile() error codes into POSIX error codes
1700        was out-of-date, and there was no check on the pcre_compile() error code
1701        being within the table. This could lead to an OK return being given in
1702        error.
1704    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1705        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1706        in a Windows environment.
1708    3.  The pcregrep --count option prints the count for each file even when it is
1709        zero, as does GNU grep. However, pcregrep was also printing all files when
1710        --files-with-matches was added. Now, when both options are given, it prints
1711        counts only for those files that have at least one match. (GNU grep just
1712        prints the file name in this circumstance, but including the count seems
1713        more useful - otherwise, why use --count?) Also ensured that the
1714        combination -clh just lists non-zero counts, with no names.
1716    4.  The long form of the pcregrep -F option was incorrectly implemented as
1717        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1718        but it seems right to fix it, and I didn't think it was worth preserving
1719        the old behaviour.
1721    5.  The command line items --regex=pattern and --regexp=pattern were not
1722        recognized by pcregrep, which required --regex pattern or --regexp pattern
1723        (with a space rather than an '='). The man page documented the '=' forms,
1724        which are compatible with GNU grep; these now work.
1726    6.  No libpcreposix.pc file was created for pkg-config; there was just
1727        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1729    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1730        when UCP support is not needed, by modifying the Python script that
1731        generates it from Unicode data files. This should not matter if the module
1732        is correctly used as a library, but I received one complaint about 50K of
1733        unwanted data. My guess is that the person linked everything into his
1734        program rather than using a library. Anyway, it does no harm.
1736    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1737        was a minimum greater than 1 for a wide character in a possessive
1738        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1739        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1740        character. Chaos in the form of incorrect output or a compiling loop could
1741        result.
1743    9.  The restrictions on what a pattern can contain when partial matching is
1744        requested for pcre_exec() have been removed. All patterns can now be
1745        partially matched by this function. In addition, if there are at least two
1746        slots in the offset vector, the offset of the earliest inspected character
1747        for the match and the offset of the end of the subject are set in them when
1748        PCRE_ERROR_PARTIAL is returned.
1750    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1751        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1752        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1753        and may be more useful for multi-segment matching.
1755    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1756        used to be given if ever the end of the subject was reached; now it is
1757        given only if matching could not proceed because another character was
1758        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1759        string "Z", which now yields "no match" instead of "partial match". In the
1760        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1761        final character ended with (*FAIL).
1763    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1764        if the pattern had a "must contain" character that was already found in the
1765        earlier partial match, unless partial matching was again requested. For
1766        example, with the pattern /dog.(body)?/, the "must contain" character is
1767        "g". If the first part-match was for the string "dog", restarting with
1768        "sbody" failed. This bug has been fixed.
1770    13. The string returned by pcre_dfa_exec() after a partial match has been
1771        changed so that it starts at the first inspected character rather than the
1772        first character of the match. This makes a difference only if the pattern
1773        starts with a lookbehind assertion or \b or \B (\K is not supported by
1774        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1775        matching functions compatible, and I think it's the right thing to do.
1777    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1778        so that the demonstration program is easily available in environments where
1779        PCRE has not been installed from source.
1781    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1782        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1783        library.
1785    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1786        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1787        is not the first non-POSIX option to be added. Clearly some people find
1788        these options useful.
1790    17. If a caller to the POSIX matching function regexec() passes a non-zero
1791        value for nmatch with a NULL value for pmatch, the value of
1792        nmatch is forced to zero.
1794    18. RunGrepTest did not have a test for the availability of the -u option of
1795        the diff command, as RunTest does. It now checks in the same way as
1796        RunTest, and also checks for the -b option.
1798    19. If an odd number of negated classes containing just a single character
1799        interposed, within parentheses, between a forward reference to a named
1800        subpattern and the definition of the subpattern, compilation crashed with
1801        an internal error, complaining that it could not find the referenced
1802        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1803        [The bug was that it was starting one character too far in when skipping
1804        over the character class, thus treating the ] as data rather than
1805        terminating the class. This meant it could skip too much.]
1807    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1808        /g option in pcretest when the pattern contains \K, which makes it possible
1809        to have an empty string match not at the start, even when the pattern is
1810        anchored. Updated pcretest and pcredemo to use this option.
1812    21. If the maximum number of capturing subpatterns in a recursion was greater
1813        than the maximum at the outer level, the higher number was returned, but
1814        with unset values at the outer level. The correct (outer level) value is
1815        now given.
1817    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1818        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1819        make it do so. The string so far is captured, making this feature
1820        compatible with Perl.
1822    23. The tests have been re-organized, adding tests 11 and 12, to make it
1823        possible to check the Perl 5.10 features against Perl 5.10.
1825    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1826        pattern matches a fixed length string. PCRE did not allow this; now it
1827        does. Neither allows recursion.
1829    25. I finally figured out how to implement a request to provide the minimum
1830        length of subject string that was needed in order to match a given pattern.
1831        (It was back references and recursion that I had previously got hung up
1832        on.) This code has now been added to pcre_study(); it finds a lower bound
1833        to the length of subject needed. It is not necessarily the greatest lower
1834        bound, but using it to avoid searching strings that are too short does give
1835        some useful speed-ups. The value is available to calling programs via
1836        pcre_fullinfo().
1838    26. While implementing 25, I discovered to my embarrassment that pcretest had
1839        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1840        study optimizations had never been tested with that matching function.
1841        Oops. What is worse, even when it was passed study data, there was a bug in
1842        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1843        were also very few tests of studied patterns with pcre_dfa_exec().
1845    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1846        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1847        on the other side of the coin, they are no longer allowed to have different
1848        names, because these cannot be distinguished in PCRE, and this has caused
1849        confusion. (This is a difference from Perl.)
1851    28. When duplicate subpattern names are present (necessarily with different
1852        numbers, as required by 27 above), and a test is made by name in a
1853        conditional pattern, either for a subpattern having been matched, or for
1854        recursion in such a pattern, all the associated numbered subpatterns are
1855        tested, and the overall condition is true if the condition is true for any
1856        one of them. This is the way Perl works, and is also more like the way
1857        testing by number works.
1860    Version 7.9 11-Apr-09
1861    ---------------------
1863    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1864        (pcretest), all targets were linked against these libraries. This included
1865        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1866        libraries. This caused unwanted dependencies to be created. This problem
1867        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1868        pcretest is linked with readline.
1870    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1871        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1872        moved outside it again, because FALSE and TRUE are already defined in AIX,
1873        but BOOL is not.
1875    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1876        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1878    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1879        hyphens) following file names and line numbers when outputting matching
1880        lines. This is not true; no spaces are inserted. I have also clarified the
1881        wording for the --colour (or --color) option.
1883    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1884        was not coloured; this is different to GNU grep, so I have changed it to be
1885        the same.
1887    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1888        each matching line was coloured. Now it goes on to look for further matches
1889        of any of the test patterns, which is the same behaviour as GNU grep.
1891    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1892        doesn't make sense to accept an empty string match in pcregrep, so I have
1893        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1894        seems to be how GNU grep behaves. [But see later change 40 for release
1895        8.33.]
1897    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1898        start or after a newline", because the conditional assertion was not being
1899        correctly handled. The rule now is that both the assertion and what follows
1900        in the first alternative must satisfy the test.
1902    9.  If auto-callout was enabled in a pattern with a conditional group whose
1903        condition was an assertion, PCRE could crash during matching, both with
1904        pcre_exec() and pcre_dfa_exec().
1906    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1907        used for matching.
1909    11. Unicode property support in character classes was not working for
1910        characters (bytes) greater than 127 when not in UTF-8 mode.
1912    12. Added the -M command line option to pcretest.
1914    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1916    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1918    16. Added comments and documentation about mis-use of no_arg in the C++
1919        wrapper.
1921    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1922        from Martin Jerabek that uses macro names for all relevant character and
1923        string constants.
1925    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1926        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1927        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1928        these, but not everybody uses configure.
1930    19. A conditional group that had only one branch was not being correctly
1931        recognized as an item that could match an empty string. This meant that an
1932        enclosing group might also not be so recognized, causing infinite looping
1933        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1934        with the subject "ab", where knowledge that the repeated group can match
1935        nothing is needed in order to break the loop.
1937    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1938        exec(), but without supplying a callout function, matching went wrong.
1940    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1941        leak if the size of the offset vector was greater than 30. When the vector
1942        is smaller, the saved offsets during recursion go onto a local stack
1943        vector, but for larger vectors malloc() is used. It was failing to free
1944        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1945        error, in fact).
1947    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1948        heapframe that is used only when UTF-8 support is enabled. This caused no
1949        problem, but was untidy.
1951    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1952        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1953        included within another project.
1955    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1956        slightly modified by me:
1958          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1959              not building pcregrep.
1961          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1962              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1964    25. Forward references, both numeric and by name, in patterns that made use of
1965        duplicate group numbers, could behave incorrectly or give incorrect errors,
1966        because when scanning forward to find the reference group, PCRE was not
1967        taking into account the duplicate group numbers. A pattern such as
1968        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1970    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1971        the feature of a custom pointer more persuasive (as requested by a user).
1973    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1974        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1975        pre-defined.
1977    28. Added support for (*UTF8) at the start of a pattern.
1979    29. Arrange for flags added by the "release type" setting in CMake to be shown
1980        in the configuration summary.
1983    Version 7.8 05-Sep-08
1984    ---------------------
1986    1.  Replaced UCP searching code with optimized version as implemented for Ad
1987        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1988        stage table and inline lookup instead of a function, giving speed ups of 2
1989        to 5 times on some simple patterns that I tested. Permission was given to
1990        distribute the MultiStage2.py script that generates the tables (it's not in
1991        the tarball, but is in the Subversion repository).
1993    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1994        scripts.
1996    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1997        a group with a zero qualifier. The result of the study could be incorrect,
1998        or the function might crash, depending on the pattern.
2000    4.  Caseless matching was not working for non-ASCII characters in back
2001        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2002        It now works when Unicode Property Support is available.
2004    5.  In pcretest, an escape such as \x{de} in the data was always generating
2005        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2006        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2007        truncation.
2009    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2011    7.  Added two (int) casts to pcregrep when printing the difference of two
2012        pointers, in case they are 64-bit values.
2014    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
2015        test 2 if it fails.
2017    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2018        and a #define of that name to empty if it is not externally set. This is to
2019        allow users of MSVC to set it if necessary.
2021    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2022        the convenience functions in the pcre_get.c source file.
2024    11. An option change at the start of a pattern that had top-level alternatives
2025        could cause overwriting and/or a crash. This command provoked a crash in
2026        some environments:
2028          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2030        This potential security problem was recorded as CVE-2008-2371.
2032    12. For a pattern where the match had to start at the beginning or immediately
2033        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2034        pcre_dfa_exec() could read past the end of the passed subject if there was
2035        no match. To help with detecting such bugs (e.g. with valgrind), I modified
2036        pcretest so that it places the subject at the end of its malloc-ed buffer.
2038    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2039        exec() might read past the end of the data buffer in UTF-8 mode.
2041    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2042        the data contained the byte 0x85 as part of a UTF-8 character within its
2043        first line. This applied both to normal and DFA matching.
2045    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2046        /^[^d]*?$/8 failed to match "abc".
2048    16. Added a missing copyright notice to pcrecpp_internal.h.
2050    17. Make it more clear in the documentation that values returned from
2051        pcre_exec() in ovector are byte offsets, not character counts.
2053    18. Tidied a few places to stop certain compilers from issuing warnings.
2055    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2056        supplied by Stefan Weber. I made a further small update for 7.8 because
2057        there is a change of source arrangements: the pcre_searchfuncs.c module is
2058        replaced by pcre_ucd.c.
2061    Version 7.7 07-May-08
2062    ---------------------
2064    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
2065        a string to a long long, pretend we don't even have a long long." This is
2066        done by checking for the strtoq, strtoll, and _strtoi64 functions.
2068    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2069        pre-7.6 versions, which defined a global no_arg variable instead of putting
2070        it in the RE class. (See also #8 below.)
2072    3.  Remove a line of dead code, identified by coverity and reported by Nuno
2073        Lopes.
2075    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
2077        (1) The include/exclude patterns were being applied to the whole pathnames
2078            of files, instead of just to the final components.
2080        (2) If there was more than one level of directory, the subdirectories were
2081            skipped unless they satisfied the include/exclude conditions. This is
2082            inconsistent with GNU grep (and could even be seen as contrary to the
2083            pcregrep specification - which I improved to make it absolutely clear).
2084            The action now is always to scan all levels of directory, and just
2085            apply the include/exclude patterns to regular files.
2087    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2088        --exclude_dir in the tests to avoid scanning .svn directories.
2090    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
2091        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2092        doesn't support NULs in patterns.
2094    7.  Added some missing "const"s to declarations of static tables in
2095        pcre_compile.c and pcre_dfa_exec.c.
2097    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2098        caused by fix #2  above. (Subsequently also a second patch to fix the
2099        first patch. And a third patch - this was a messy problem.)
2101    9.  Applied Craig's patch to remove the use of push_back().
2103    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2104        matching function regexec().
2106    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2107        which, however, unlike Perl's \g{...}, are subroutine calls, not back
2108        references. PCRE supports relative numbers with this syntax (I don't think
2109        Oniguruma does).
2111    12. Previously, a group with a zero repeat such as (...){0} was completely
2112        omitted from the compiled regex. However, this means that if the group
2113        was called as a subroutine from elsewhere in the pattern, things went wrong
2114        (an internal error was given). Such groups are now left in the compiled
2115        pattern, with a new opcode that causes them to be skipped at execution
2116        time.
2118    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2119        to the way PCRE behaves:
2121        (a) A lone ] character is dis-allowed (Perl treats it as data).
2123        (b) A back reference to an unmatched subpattern matches an empty string
2124            (Perl fails the current match path).
2126        (c) A data ] in a character class must be notated as \] because if the
2127            first data character in a class is ], it defines an empty class. (In
2128            Perl it is not possible to have an empty class.) The empty class []
2129            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2130            The negative empty class [^] matches any one character, independently
2131            of the DOTALL setting.
2133    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2134        non-existent subpattern following a character class starting with ']' and
2135        containing () gave an internal compiling error instead of "reference to
2136        non-existent subpattern". Fortunately, when the pattern did exist, the
2137        compiled code was correct. (When scanning forwards to check for the
2138        existence of the subpattern, it was treating the data ']' as terminating
2139        the class, so got the count wrong. When actually compiling, the reference
2140        was subsequently set up correctly.)
2142    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2143        it was being rejected as not supported by pcre_dfa_exec(), even though
2144        other assertions are supported. I have made pcre_dfa_exec() support
2145        (*FAIL).
2147    16. The implementation of 13c above involved the invention of a new opcode,
2148        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2149        cannot be changed at match time, I realized I could make a small
2150        improvement to matching performance by compiling OP_ALLANY instead of
2151        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2152        on the OP_ANY path.
2154    17. Compiling pcretest on Windows with readline support failed without the
2155        following two fixes: (1) Make the unistd.h include conditional on
2156        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2158    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2159        ncurses library to be included for pcretest when ReadLine support is
2160        requested, but also to allow for it to be overridden. This patch came from
2161        Daniel Bergström.
2163    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2164        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2165        any errors with the current Unicode tables. Thanks to Peter Kankowski for
2166        spotting this.
2169    Version 7.6 28-Jan-08
2170    ---------------------
2172    1.  A character class containing a very large number of characters with
2173        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2174        overflow.
2176    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
2177        HAVE_LONG_LONG is not defined.
2179    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
2180        bring them up to date and include new features. This patch includes:
2182        - Fixed PH's badly added libz and libbz2 support.
2183        - Fixed a problem with static linking.
2184        - Added pcredemo. [But later removed - see 7 below.]
2185        - Fixed dftables problem and added an option.
2186        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2187            HAVE_LONG_LONG.
2188        - Added readline support for pcretest.
2189        - Added an listing of the option settings after cmake has run.
2191    4.  A user submitted a patch to Makefile that makes it easy to create
2192        "pcre.dll" under mingw when using Configure/Make. I added stuff to
2193        Makefile.am that cause it to include this special target, without
2194        affecting anything else. Note that the same mingw target plus all
2195        the other distribution libraries and programs are now supported
2196        when configuring with CMake (see 6 below) instead of with
2197        Configure/Make.
2199    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2200        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2201        exported in the Windows port". It has not yet been confirmed that the patch
2202        solves the problem, but it does no harm.
2204    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2205        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2206        with CMake, and also correct the comment about stack recursion.
2208    7.  Remove the automatic building of pcredemo from the ./configure system and
2209        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2210        of a program that users should build themselves after PCRE is installed, so
2211        building it automatically is not really right. What is more, it gave
2212        trouble in some build environments.
2214    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
2217    Version 7.5 10-Jan-08
2218    ---------------------
2220    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
2221        values in parens when parsing an RE using the C++ wrapper."
2223    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
2224        Characters greater than 255 were excluded from the class instead of being
2225        included.
2227    3.  The same bug as (2) above applied to negated POSIX classes such as
2228        [:^space:].
2230    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2231        defined or documented. It seems to have been a typo for PCRE_STATIC, so
2232        I have changed it.
2234    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
2235        first named subpattern) and a construct such as (?&a) would reference the
2236        first named subpattern whose name started with "a" (in other words, the
2237        length check was missing). Both these problems are fixed. "Subpattern name
2238        expected" is now given for (?&) (a zero-length name), and this patch also
2239        makes it give the same error for \k'' (previously it complained that that
2240        was a reference to a non-existent subpattern).
2242    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
2243        this is right because (?- can be followed by option settings as well as by
2244        digits. I have, however, made the messages clearer.
2246    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2247        than the number used in the conditional) now cause a compile-time error.
2248        This is actually not compatible with Perl, which accepts such patterns, but
2249        treats the conditional as always being FALSE (as PCRE used to), but it
2250        seems to me that giving a diagnostic is better.
2252    8.  Change "alphameric" to the more common word "alphanumeric" in comments
2253        and messages.
2255    9.  Fix two occurrences of "backslash" in comments that should have been
2256        "backspace".
2258    10. Remove two redundant lines of code that can never be obeyed (their function
2259        was moved elsewhere).
2261    11. The program that makes PCRE's Unicode character property table had a bug
2262        which caused it to generate incorrect table entries for sequences of
2263        characters that have the same character type, but are in different scripts.
2264        It amalgamated them into a single range, with the script of the first of
2265        them. In other words, some characters were in the wrong script. There were
2266        thirteen such cases, affecting characters in the following ranges:
2268          U+002b0 - U+002c1
2269          U+0060c - U+0060d
2270          U+0061e - U+00612
2271          U+0064b - U+0065e
2272          U+0074d - U+0076d
2273          U+01800 - U+01805
2274          U+01d00 - U+01d77
2275          U+01d9b - U+01dbf
2276          U+0200b - U+0200f
2277          U+030fc - U+030fe
2278          U+03260 - U+0327f
2279          U+0fb46 - U+0fbb1
2280          U+10450 - U+1049d
2282    12. The -o option (show only the matching part of a line) for pcregrep was not
2283        compatible with GNU grep in that, if there was more than one match in a
2284        line, it showed only the first of them. It now behaves in the same way as
2285        GNU grep.
2287    13. If the -o and -v options were combined for pcregrep, it printed a blank
2288        line for every non-matching line. GNU grep prints nothing, and pcregrep now
2289        does the same. The return code can be used to tell if there were any
2290        non-matching lines.
2292    14. Added --file-offsets and --line-offsets to pcregrep.
2294    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2295        infinitely looping recursion. The bug was that positive lookaheads were not
2296        being skipped when checking for a possible empty match (negative lookaheads
2297        and both kinds of lookbehind were skipped).
2299    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2300        inclusion of <windows.h> to before rather than after the definition of
2301        INVALID_FILE_ATTRIBUTES (patch from David Byron).
2303    17. Specifying a possessive quantifier with a specific limit for a Unicode
2304        character property caused pcre_compile() to compile bad code, which led at
2305        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2306        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2307        caused the error; without that there was no problem.
2309    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2311    19. Added --enable-pcretest-libreadline.
2313    20. In pcrecpp.cc, the variable 'count' was incremented twice in
2314        RE::GlobalReplace(). As a result, the number of replacements returned was
2315        double what it should be. I removed one of the increments, but Craig sent a
2316        later patch that removed the other one (the right fix) and added unit tests
2317        that check the return values (which was not done before).
2319    21. Several CMake things:
2321        (1) Arranged that, when cmake is used on Unix, the libraries end up with
2322            the names libpcre and libpcreposix, not just pcre and pcreposix.
2324        (2) The above change means that pcretest and pcregrep are now correctly
2325            linked with the newly-built libraries, not previously installed ones.
2329    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2330        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2331        UTF-8 newline character). The key issue is that the pattern starts .*;
2332        this means that the match must be either at the beginning, or after a
2333        newline. The bug was in the code for advancing after a failed match and
2334        checking that the new position followed a newline. It was not taking
2335        account of UTF-8 characters correctly.
2337    23. PCRE was behaving differently from Perl in the way it recognized POSIX
2338        character classes. PCRE was not treating the sequence [:...:] as a
2339        character class unless the ... were all letters. Perl, however, seems to
2340        allow any characters between [: and :], though of course it rejects as
2341        unknown any "names" that contain non-letters, because all the known class
2342        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2343        for example, whereas PCRE did not - it did not recognize a POSIX character
2344        class. This seemed a bit dangerous, so the code has been changed to be
2345        closer to Perl. The behaviour is not identical to Perl, because PCRE will
2346        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2347        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2348        Perl does, and where it didn't before.
2350    24. Rewrite so as to remove the single use of %n from pcregrep because in some
2351        Windows environments %n is disabled by default.
2354    Version 7.4 21-Sep-07
2355    ---------------------
2357    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
2358        means that a class such as [\s] counted as "explicit reference to CR or
2359        LF". That isn't really right - the whole point of the change was to try to
2360        help when there was an actual mention of one of the two characters. So now
2361        the change happens only if \r or \n (or a literal CR or LF) character is
2362        encountered.
2364    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
2365        of both had grown to the point where there were only 3 bits left.
2366        Fortunately, there was spare space in the data structure, and so I have
2367        moved the internal flags into a new 16-bit field to free up more option
2368        bits.
2370    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2371        but did not set the internal JCHANGED flag - either of these is enough to
2372        control the way the "get" function works - but the PCRE_INFO_JCHANGED
2373        facility is supposed to tell if (?J) was ever used, so now (?J) at the
2374        start sets both bits.
2376    4.  Added options (at build time, compile time, exec time) to change \R from
2377        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2379    5.  doc/pcresyntax.html was missing from the distribution.
2381    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2382        compatibility, even though it is no longer used.
2384    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2385        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2386        windows.h file is present (where different names are used). [This was
2387        reversed later after testing - see 16 below.]
2389    8.  Changed all #include <config.h> to #include "config.h". There were also
2390        some further <pcre.h> cases that I changed to "pcre.h".
2392    9.  When pcregrep was used with the --colour option, it missed the line ending
2393        sequence off the lines that it output.
2395    10. It was pointed out to me that arrays of string pointers cause lots of
2396        relocations when a shared library is dynamically loaded. A technique of
2397        using a single long string with a table of offsets can drastically reduce
2398        these. I have refactored PCRE in four places to do this. The result is
2399        dramatic:
2401          Originally:                          290
2402          After changing UCP table:            187
2403          After changing error message table:   43
2404          After changing table of "verbs"       36
2405          After changing table of Posix names   22
2407        Thanks to the folks working on Gregex for glib for this insight.
2409    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2410        unicode-properties was also set.
2412    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2414    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2415        checked only for CRLF.
2417    14. Added casts to pcretest.c to avoid compiler warnings.
2419    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2421    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2422        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2423        entirely. This removes changes made in 7 above.
2425    17. The CMake files have been updated, and there is now more information about
2426        building with CMake in the NON-UNIX-USE document.
2429    Version 7.3 28-Aug-07
2430    ---------------------
2432     1. In the rejigging of the build system that eventually resulted in 7.1, the
2433        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2434        brackets there is not right, since it causes compilers to look for an
2435        installed pcre.h, not the version that is in the source that is being
2436        compiled (which of course may be different). I have changed it back to:
2438          #include "pcre.h"
2440        I have a vague recollection that the change was concerned with compiling in
2441        different directories, but in the new build system, that is taken care of
2442        by the VPATH setting the Makefile.
2444     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2445        when the subject happened to end in the byte 0x85 (e.g. if the last
2446        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2447        characters but of course it shouldn't be taken as a newline when it is part
2448        of another character. The bug was that, for an unlimited repeat of . in
2449        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2450        characters when looking for a newline.
2452     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2454     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2455        in debug output.
2457     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2458        long printing in the pcrecpp unittest when running under MinGW.
2460     6. ESC_K was left out of the EBCDIC table.
2462     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2463        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2464        limit also applies to "virtual nesting" when a pattern is recursive, and in
2465        this case 1000 isn't so big. I have been able to remove this limit at the
2466        expense of backing off one optimization in certain circumstances. Normally,
2467        when pcre_exec() would call its internal match() function recursively and
2468        immediately return the result unconditionally, it uses a "tail recursion"
2469        feature to save stack. However, when a subpattern that can match an empty
2470        string has an unlimited repetition quantifier, it no longer makes this
2471        optimization. That gives it a stack frame in which to save the data for
2472        checking that an empty string has been matched. Previously this was taken
2473        from the 1000-entry workspace that had been reserved. So now there is no
2474        explicit limit, but more stack is used.
2476     8. Applied Daniel's patches to solve problems with the import/export magic
2477        syntax that is required for Windows, and which was going wrong for the
2478        pcreposix and pcrecpp parts of the library. These were overlooked when this
2479        problem was solved for the main library.
2481     9. There were some crude static tests to avoid integer overflow when computing
2482        the size of patterns that contain repeated groups with explicit upper
2483        limits. As the maximum quantifier is 65535, the maximum group length was
2484        set at 30,000 so that the product of these two numbers did not overflow a
2485        32-bit integer. However, it turns out that people want to use groups that
2486        are longer than 30,000 bytes (though not repeat them that many times).
2487        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2488        made it possible to implement the integer overflow checks in a much more
2489        dynamic way, which I have now done. The artificial limitation on group
2490        length has been removed - we now have only the limit on the total length of
2491        the compiled pattern, which depends on the LINK_SIZE setting.
2493    10. Fixed a bug in the documentation for get/copy named substring when
2494        duplicate names are permitted. If none of the named substrings are set, the
2495        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2496        empty string.
2498    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2499        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2500        because the ] is interpreted as the first data character and the
2501        terminating ] is not found. PCRE has been made compatible with Perl in this
2502        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2503        cause memory overwriting.
2505    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2506        string has been matched (to stop an infinite loop). It was not recognizing
2507        a conditional subpattern that could match an empty string if that
2508        subpattern was within another subpattern. For example, it looped when
2509        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
2510        condition was not nested. This bug has been fixed.
2512    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2513        past the start of the subject in the presence of bytes with the top bit
2514        set, for example "\x8aBCD".
2516    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2517        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2519    14. Optimized (?!) to (*FAIL).
2521    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2522        This restricts code points to be within the range 0 to 0x10FFFF, excluding
2523        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2524        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2525        does: it's just the validity check that is more restrictive.
2527    16. Inserted checks for integer overflows during escape sequence (backslash)
2528        processing, and also fixed erroneous offset values for syntax errors during
2529        backslash processing.
2531    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2532        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2534    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2535        caused an overrun.
2537    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2538        something other than just ASCII characters) inside a group that had an
2539        unlimited repeat caused a loop at compile time (while checking to see
2540        whether the group could match an empty string).
2542    20. Debugging a pattern containing \p or \P could cause a crash. For example,
2543        [\P{Any}] did so. (Error in the code for printing property names.)
2545    21. An orphan \E inside a character class could cause a crash.
2547    22. A repeated capturing bracket such as (A)? could cause a wild memory
2548        reference during compilation.
2550    23. There are several functions in pcre_compile() that scan along a compiled
2551        expression for various reasons (e.g. to see if it's fixed length for look
2552        behind). There were bugs in these functions when a repeated \p or \P was
2553        present in the pattern. These operators have additional parameters compared
2554        with \d, etc, and these were not being taken into account when moving along
2555        the compiled data. Specifically:
2557        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2558            length.
2560        (b) An item such as \pL+ within a repeated group could cause crashes or
2561            loops.
2563        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2564            "reference to non-existent subpattern" error.
2566        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2568    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2569        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2571    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2573    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2574        character were causing crashes (broken optimization).
2576    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2577        \p or \P) caused a compile-time loop.
2579    28. More problems have arisen in unanchored patterns when CRLF is a valid line
2580        break. For example, the unstudied pattern [\r\n]A does not match the string
2581        "\r\nA" because change 7.0/46 below moves the current point on by two
2582        characters after failing to match at the start. However, the pattern \nA
2583        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2584        the same is true. There doesn't seem any very clean way out of this, but
2585        what I have chosen to do makes the common cases work: PCRE now takes note
2586        of whether there can be an explicit match for \r or \n anywhere in the
2587        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2588        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2589        pattern has explicit CR or LF references.
2591    29. Added (*CR) etc for changing newline setting at start of pattern.
2594    Version 7.2 19-Jun-07
2595  ---------------------  ---------------------
2597   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 40  Version 7.2 05-June-07 Line 2630  Version 7.2 05-June-07
2631      (f) \g{name} is another synonym - part of Perl 5.10's unification of      (f) \g{name} is another synonym - part of Perl 5.10's unification of
2632          reference syntax.          reference syntax.
2634      (g) (?| introduces a group in which the numbering of parentheses in each      (g) (?| introduces a group in which the numbering of parentheses in each
2635          alternative starts with the same number.          alternative starts with the same number.
2637        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2639   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
# Line 58  Version 7.2 05-June-07 Line 2650  Version 7.2 05-June-07
2650      alternatives. The 1000-alternative test pattern now uses 12 bytes of      alternatives. The 1000-alternative test pattern now uses 12 bytes of
2651      workspace instead of running out of the 4096 that are available.      workspace instead of running out of the 4096 that are available.
2653    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2655    11. Applied patch from Google to remove an optimization that didn't quite work.
2656        The report of the bug said:
2658          pcrecpp::RE("a*").FullMatch("aaa") matches, while
2659          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2660          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2662    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2663        it matched the wrong number of bytes.
2666  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
2667  ---------------------  ---------------------

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