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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.01 06-Jan-10  Version 8.34 xx-xxxx-201x
5  ----------------------  --------------------------
7    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8        executable memory. Patch inspired by Carsten Klein.
10    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
11        this macro is never tested and has no effect, because the work to support
12        coverage involves only compiling and linking options and special targets in
13        the Makefile. The comment in config.h implied that defining the macro would
14        enable coverage support, which is totally false. There was also support for
15        setting this macro in the CMake files (my fault, I just copied it from
16        configure). SUPPORT_GCOV has now been removed.
18    3.  Make a small performance improvement in strlen16() and strlen32() in
19        pcretest.
21    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
22        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
23        these cases). There was also one in pcretest.c.
25    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
27    6.  In UTF mode, the code for checking whether a group could match an empty
28        string (which is used for indefinitely repeated groups to allow for
29        breaking an infinite loop) was broken when the group contained a repeated
30        negated single-character class with a character that occupied more than one
31        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
32        UTF-8 mode). The effect was undefined: the group might or might not be
33        deemed as matching an empty string, or the program might have crashed.
35    7.  The code for checking whether a group could match an empty string was not
36        recognizing that \h, \H, \v, \V, and \R must match a character.
38    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
39        an empty string. If it can, pcretest shows this in its information output.
41    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
42        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
43        matched by pcre_exec() without using JIT:
45        (a) If the rest of the pattern did not match after a maximal run of
46            grapheme clusters, the code for backing up to try with fewer of them
47            did not always back up over a full grapheme when characters that do not
48            have the modifier quality were involved, e.g. Hangul syllables.
50        (b) If the match point in a subject started with modifier character, and
51            there was no match, the code could incorrectly back up beyond the match
52            point, and potentially beyond the first character in the subject,
53            leading to a segfault or an incorrect match result.
55    10. A conditional group with an assertion condition could lead to PCRE
56        recording an incorrect first data item for a match if no other first data
57        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
58        first data item, and therefore matched "ca" after "c" instead of at the
59        start.
61    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
62        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
64    12. The source of pcregrep now includes z/OS-specific code so that it can be
65        compiled for z/OS as part of the special z/OS distribution.
67    13. Added the -T and -TM options to pcretest.
69    14. The code in pcre_compile.c for creating the table of named capturing groups
70        has been refactored. Instead of creating the table dynamically during the
71        actual compiling pass, the information is remembered during the pre-compile
72        pass (on the stack unless there are more than 20 named groups, in which
73        case malloc() is used) and the whole table is created before the actual
74        compile happens. This has simplified the code (it is now nearly 150 lines
75        shorter) and prepared the way for better handling of references to groups
76        with duplicate names.
78    15. A back reference to a named subpattern when there is more than one of the
79        same name now checks them in the order in which they appear in the pattern.
80        The first one that is set is used for the reference. Previously only the
81        first one was inspected. This change makes PCRE more compatible with Perl.
83    16. Unicode character properties were updated from Unicode 6.3.0.
85    17. The compile-time code for auto-possessification has been refactored, based
86        on a patch by Zoltan Herczeg. It now happens after instead of during
87        compilation. The code is cleaner, and more cases are handled. The option
88        PCRE_NO_AUTO_POSSESSIFY is added for testing purposes, and the -O and /O
89        options in pcretest are provided to set it.
91    18. The character VT has been added to the set of characters that match \s and
92        are generally treated as white space, following this same change in Perl
93        5.18. There is now no difference between "Perl space" and "POSIX space".
95    19. The code for checking named groups as conditions, either for being set or
96        for being recursed, has been refactored (this is related to 14 and 15
97        above). Processing unduplicated named groups should now be as fast at
98        numerical groups, and processing duplicated groups should be faster than
99        before.
101    20. Two patches to the CMake build system, by Alexander Barkov:
103          (1) Replace the "source" command by "." in CMakeLists.txt because
104              "source" is a bash-ism.
106          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
107              without these the CMake build does not work on Solaris.
109    21. Perl has changed its handling of \8 and \9. If there is no previously
110        encountered capturing group of those numbers, they are treated as the
111        literal characters 8 and 9 instead of a binary zero followed by the
112        literals. PCRE now does the same.
114    22. Following Perl, added \o{} to specify codepoints in octal, making it
115        possible to specify values greater than 0777 and also making them
116        unambiguous.
118    23. Perl now gives an error for missing closing braces after \x{... instead of
119        treating the string as literal. PCRE now does the same.
121    24. RunTest used to grumble if an inappropriate test was selected explicitly,
122        but just skip it when running all tests. This make it awkward to run ranges
123        of tests when one of them was inappropriate. Now it just skips any
124        inappropriate tests, as it always did when running all tests.
126    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
127        character types such as \d or \w, too many callouts were inserted, and the
128        data that they returned was rubbish.
130    26. In UCP mode, \s was not matching two of the characters that Perl matches,
131        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
132        were matched by \h. The code has now been refactored so that the lists of
133        the horizontal and vertical whitespace characters used for \h and \v (which
134        are defined only in one place) are now also used for \s.
136    27. Add JIT support for the 64 bit TileGX architecture.
137        Patch by Jiong Wang (Tilera Corporation).
139    28. Possessive quantifiers for classes (both explicit and automatically
140        generated) now use special opcodes instead of wrapping in ONCE brackets.
142    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
143        (because it's meaningless), this was not happening when PCRE_CASELESS was
144        set. Not wrong, but inefficient.
146    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
147        properties for \w, \d, etc) is present in a test regex. Otherwise if the
148        test contains no characters greater than 255, Perl doesn't realise it
149        should be using Unicode semantics.
151    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
152        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
153        does in Unicode mode.
155    32. Added the "forbid" facility to pcretest so that putting tests into the
156        wrong test files can sometimes be quickly detected.
158    33. There is now a limit (default 250) on the depth of nesting of parentheses.
159        This limit is imposed to control the amount of system stack used at compile
160        time. It can be changed at build time by --with-parens-nest-limit=xxx or
161        the equivalent in CMake.
163    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
164        errors. Perl warns for these when in warning mode, but PCRE has no facility
165        for giving warnings.
168    Version 8.33 28-May-2013
169    ------------------------
171    1.  Added 'U' to some constants that are compared to unsigned integers, to
172        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
173        variables that are added to signed variables, to ensure the result is
174        signed and can be negated.
176    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
177        CMake config files.
179    3.  Revise the creation of config.h.generic so that all boolean macros are
180        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
181        overriding via -D on the command line possible.
183    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
184        to unsigned int is reported to make a quite noticeable speed difference in
185        a specific Windows environment. Testing on Linux did also appear to show
186        some benefit (and it is clearly not harmful). Also fixed the definition of
187        Xop which should be unsigned.
189    5.  Related to (4), changing the definition of the intermediate variable cc
190        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
191        improvements.
193    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
194        unnecessary spaces.
196    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
197        and later.
199    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
201    9.  Optimizing fast_forward_start_bits in JIT.
203    10. Adding support for callouts in JIT, and fixing some issues revealed
204        during this work. Namely:
206        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
208        (b) Minimum length was not checked before the matching is started.
210    11. The value of capture_last that is passed to callouts was incorrect in some
211        cases when there was a capture on one path that was subsequently abandoned
212        after a backtrack. Also, the capture_last value is now reset after a
213        recursion, since all captures are also reset in this case.
215    12. The interpreter no longer returns the "too many substrings" error in the
216        case when an overflowing capture is in a branch that is subsequently
217        abandoned after a backtrack.
219    13. In the pathological case when an offset vector of size 2 is used, pcretest
220        now prints out the matched string after a yield of 0 or 1.
222    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
223        Only supported by the JIT compiler at the moment.
225    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
227    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
228        offset of the starting point of the matching process, provided the offsets
229        vector is large enough.
231    17. The \A escape now records a lookbehind value of 1, though its execution
232        does not actually inspect the previous character. This is to ensure that,
233        in partial multi-segment matching, at least one character from the old
234        segment is retained when a new segment is processed. Otherwise, if there
235        are no lookbehinds in the pattern, \A might match incorrectly at the start
236        of a new segment.
238    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
240    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
241        gives some modest performance improvement in 8-bit mode.
243    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
244        be expressed in certain programming languages using Universal Character
245        Names.
247    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
248        which points out that "non characters" are not "characters that may not
249        appear in Unicode strings" but rather "characters that are reserved for
250        internal use and have only local meaning".
252    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
253        there was a conditional group that depended on an assertion, if the
254        assertion was false, the callout that immediately followed the alternation
255        in the condition was skipped when pcre_exec() was used for matching.
257    23. Allow an explicit callout to be inserted before an assertion that is the
258        condition for a conditional group, for compatibility with automatic
259        callouts, which always insert a callout at this point.
261    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
262        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
264    25. (*PRUNE) is now supported by the JIT compiler.
266    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
268    27. Fix the case where there are two or more SKIPs with arguments that may be
269        ignored.
271    28. (*SKIP) is now supported by the JIT compiler.
273    29. (*THEN) is now supported by the JIT compiler.
275    30. Update RunTest with additional test selector options.
277    31. The way PCRE handles backtracking verbs has been changed in two ways.
279        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
280        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
281        backtracking. In some cases this makes it more Perl-compatible, but Perl's
282        rather obscure rules do not always do the same thing.
284        (2) Previously, backtracking verbs were confined within assertions. This is
285        no longer the case for positive assertions, except for (*ACCEPT). Again,
286        this sometimes improves Perl compatibility, and sometimes does not.
288    32. A number of tests that were in test 2 because Perl did things differently
289        have been moved to test 1, because either Perl or PCRE has changed, and
290        these tests are now compatible.
292    32. Backtracking control verbs are now handled in the same way in JIT and
293        interpreter.
295    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
296        contained a forward subroutine reference caused a compile error.
298    34. Auto-detect and optimize limited repetitions in JIT.
300    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
301        blocking (*UTF) etc.
303    36. In the interpreter, maximizing pattern repetitions for characters and
304        character types now use tail recursion, which reduces stack usage.
306    37. The value of the max lookbehind was not correctly preserved if a compiled
307        and saved regex was reloaded on a host of different endianness.
309    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
310        of the compiled pattern block, expand the flags field from 16 to 32 bits
311        because it was almost full.
313    39. Try madvise first before posix_madvise.
315    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
316        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
317        original change locked out all matches of empty strings. This has been
318        changed so that one match of an empty string per line is recognized.
319        Subsequent searches on the same line (for colouring or for --only-matching,
320        for example) do not recognize empty strings.
322    41. Applied a user patch to fix a number of spelling mistakes in comments.
324    42. Data lines longer than 65536 caused pcretest to crash.
326    43. Clarified the data type for length and startoffset arguments for pcre_exec
327        and pcre_dfa_exec in the function-specific man pages, where they were
328        explicitly stated to be in bytes, never having been updated. I also added
329        some clarification to the pcreapi man page.
331    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
332        a segmentation fault.
335    Version 8.32 30-November-2012
336    -----------------------------
338    1.  Improved JIT compiler optimizations for first character search and single
339        character iterators.
341    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
342        Patch by Daniel Richard G.
344    3.  Single character iterator optimizations in the JIT compiler.
346    4.  Improved JIT compiler optimizations for character ranges.
348    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
349        Reported by Giuseppe D'Angelo.
351    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
352        of a line, was being set incorrectly in cases where .* appeared inside
353        atomic brackets at the start of a pattern, or where there was a subsequent
354        *PRUNE or *SKIP.
356    7.  Improved instruction cache flush for POWER/PowerPC.
357        Patch by Daniel Richard G.
359    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
360        grep:
362        (a) There is now no limit to the number of patterns to be matched.
364        (b) An error is given if a pattern is too long.
366        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
367            are now supported.
369        (d) --exclude-from and --include-from (multiple use) have been added.
371        (e) Exclusions and inclusions now apply to all files and directories, not
372            just to those obtained from scanning a directory recursively.
374        (f) Multiple uses of -f and --file-list are now supported.
376        (g) In a Windows environment, the default for -d has been changed from
377            "read" (the GNU grep default) to "skip", because otherwise the presence
378            of a directory in the file list provokes an error.
380        (h) The documentation has been revised and clarified in places.
382    9.  Improve the matching speed of capturing brackets.
384    10. Changed the meaning of \X so that it now matches a Unicode extended
385        grapheme cluster.
387    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
388        out POSIX threads when JIT support is configured.
390    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
392    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
393        structure could go wrong in environments where size_t is not the same size
394        as int.
396    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
397        set.
399    15. The EBCDIC support had decayed; later updates to the code had included
400        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
401        general tidy up of EBCDIC-related issues, and the documentation was also
402        not quite right. There is now a test that can be run on ASCII systems to
403        check some of the EBCDIC-related things (but is it not a full test).
405    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
406        in a small tidy to the code.
408    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
410    18. If the --only-matching (-o) option in pcregrep is specified multiple
411        times, each one causes appropriate output. For example, -o1 -o2 outputs the
412        substrings matched by the 1st and 2nd capturing parentheses. A separating
413        string can be specified by --om-separator (default empty).
415    19. Improving the first n character searches.
417    20. Turn case lists for horizontal and vertical white space into macros so that
418        they are defined only once.
420    21. This set of changes together give more compatible Unicode case-folding
421        behaviour for characters that have more than one other case when UCP
422        support is available.
424        (a) The Unicode property table now has offsets into a new table of sets of
425            three or more characters that are case-equivalent. The MultiStage2.py
426            script that generates these tables (the pcre_ucd.c file) now scans
427            CaseFolding.txt instead of UnicodeData.txt for character case
428            information.
430        (b) The code for adding characters or ranges of characters to a character
431            class has been abstracted into a generalized function that also handles
432            case-independence. In UTF-mode with UCP support, this uses the new data
433            to handle characters with more than one other case.
435        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
436            whose other case is greater than 256 are now correctly matched
437            caselessly. Previously, the high codepoint matched the low one, but not
438            vice versa.
440        (d) The processing of \h, \H, \v, and \ in character classes now makes use
441            of the new class addition function, using character lists defined as
442            macros alongside the case definitions of 20 above.
444        (e) Caseless back references now work with characters that have more than
445            one other case.
447        (f) General caseless matching of characters with more than one other case
448            is supported.
450    22. Unicode character properties were updated from Unicode 6.2.0
452    23. Improved CMake support under Windows. Patch by Daniel Richard G.
454    24. Add support for 32-bit character strings, and UTF-32
456    25. Major JIT compiler update (code refactoring and bugfixing).
457        Experimental Sparc 32 support is added.
459    26. Applied a modified version of Daniel Richard G's patch to create
460        pcre.h.generic and config.h.generic by "make" instead of in the
461        PrepareRelease script.
463    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
464        pcre_compile.c when checking for a zero character.
466    28. Introducing a native interface for JIT. Through this interface, the compiled
467        machine code can be directly executed. The purpose of this interface is to
468        provide fast pattern matching, so several sanity checks are not performed.
469        However, feature tests are still performed. The new interface provides
470        1.4x speedup compared to the old one.
472    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
473        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
474        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
476    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
477        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
478        the "old" RFC 2279). Instead, it ended up passing a negative length to
479        pcre_exec().
481    31. Add support for GCC's visibility feature to hide internal functions.
483    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
484        "unknown -C option" after outputting 0 or 1.
486    33. There is now support for generating a code coverage report for the test
487        suite in environments where gcc is the compiler and lcov is installed. This
488        is mainly for the benefit of the developers.
490    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
491        unaddressable using valgrind annotations, allowing valgrind to detect
492        invalid memory accesses. This is mainly for the benefit of the developers.
494    25. (*UTF) can now be used to start a pattern in any of the three libraries.
496    26. Give configure error if --enable-cpp but no C++ compiler found.
499    Version 8.31 06-July-2012
500    -------------------------
502    1.  Fixing a wrong JIT test case and some compiler warnings.
504    2.  Removed a bashism from the RunTest script.
506    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
507        to unsigned type, result still unsigned" that was given by an MS compiler
508        on encountering the code "-sizeof(xxx)".
510    4.  Partial matching support is added to the JIT compiler.
512    5.  Fixed several bugs concerned with partial matching of items that consist
513        of more than one character:
515        (a) /^(..)\1/ did not partially match "aba" because checking references was
516            done on an "all or nothing" basis. This also applied to repeated
517            references.
519        (b) \R did not give a hard partial match if \r was found at the end of the
520            subject.
522        (c) \X did not give a hard partial match after matching one or more
523            characters at the end of the subject.
525        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
526            a partial match for the string "\r".
528        (e) When newline was set to CRLF, the metacharacter "." did not recognize
529            a partial match for a CR character at the end of the subject string.
531    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
532        running pcretest, the text "(JIT)" added to the output whenever JIT is
533        actually used to run the match.
535    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
536        or /S+[+] with a digit between 1 and 7.
538    8.  OP_NOT now supports any UTF character not just single-byte ones.
540    9.  (*MARK) control verb is now supported by the JIT compiler.
542    10. The command "./RunTest list" lists the available tests without actually
543        running any of them. (Because I keep forgetting what they all are.)
547    12. Applied a (slightly modified) user-supplied patch that improves performance
548        when the heap is used for recursion (compiled with --disable-stack-for-
549        recursion). Instead of malloc and free for each heap frame each time a
550        logical recursion happens, frames are retained on a chain and re-used where
551        possible. This sometimes gives as much as 30% improvement.
553    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
554        call.
556    14. As documented, (*COMMIT) is now confined to within a positive assertion.
558    15. It is now possible to link pcretest with libedit as an alternative to
559        libreadline.
561    16. (*COMMIT) control verb is now supported by the JIT compiler.
563    17. The Unicode data tables have been updated to Unicode 6.1.0.
565    18. Added --file-list option to pcregrep.
567    19. Added binary file support to pcregrep, including the -a, --binary-files,
568        -I, and --text options.
570    20. The madvise function is renamed for posix_madvise for QNX compatibility
571        reasons. Fixed by Giuseppe D'Angelo.
573    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
575    22. Changed the option for creating symbolic links for 16-bit man pages from
576        -s to -sf so that re-installing does not cause issues.
578    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
580    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
581        matches in certain environments (the workspace was not being correctly
582        retained). Also added to pcre_dfa_exec() a simple plausibility check on
583        some of the workspace data at the beginning of a restart.
585    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
586        was not doing so when it should - probably a typo introduced by SVN 528
587        (change 8.10/14).
589    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
590        \w+ when the character tables indicated that \x{c4} was a word character.
591        There were several related cases, all because the tests for doing a table
592        lookup were testing for characters less than 127 instead of 255.
594    27. If a pattern contains capturing parentheses that are not used in a match,
595        their slots in the ovector are set to -1. For those that are higher than
596        any matched groups, this happens at the end of processing. In the case when
597        there were back references that the ovector was too small to contain
598        (causing temporary malloc'd memory to be used during matching), and the
599        highest capturing number was not used, memory off the end of the ovector
600        was incorrectly being set to -1. (It was using the size of the temporary
601        memory instead of the true size.)
603    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
604        ovector size, it uses memory at the end of the block that it has got.
606    29. Check for an overlong MARK name and give an error at compile time. The
607        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
609    30. JIT compiler update.
611    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
612        Rill for the patch.
614    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
616    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
618    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
619        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
620        was enabled.
622    35. Improve JIT code generation for greedy plus quantifier.
624    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
625        1 to "aa" instead of to an empty string. The bug affected repeated groups
626        that could potentially match an empty string.
628    37. Optimizing single character iterators in JIT.
630    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
631        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
632        codepoints that are too big for the mode are faulted, and in a UTF mode,
633        disallowed codepoints are also faulted.
635    39. If PCRE was compiled with UTF support, in three places in the DFA
636        matcher there was code that should only have been obeyed in UTF mode, but
637        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
638        processing when bytes with values greater than 127 were present. In 16-bit
639        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
640        both cases the values are those that cannot be the first data item in a UTF
641        character. The three items that might have provoked this were recursions,
642        possessively repeated groups, and atomic groups.
644    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
645        and pcregrep, because some OS require shared objects to be explicitly
646        passed to ld, causing the link step to fail if they are not.
648    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
649        mode, patterns that started with \h* or \R* might be incorrectly matched.
652    Version 8.30 04-February-2012
653    -----------------------------
655    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
656        name is defined in ctype.h.
658    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
659        only in quite long subpatterns.
661    3.  Removed the function pcre_info(), which has been obsolete and deprecated
662        since it was replaced by pcre_fullinfo() in February 2000.
664    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
665        match a (*MARK), and the match failed at the start of the subject, a
666        reference to memory before the start of the subject could occur. This bug
667        was introduced by fix 17 of release 8.21.
669    5.  A reference to an unset group with zero minimum repetition was giving
670        totally wrong answers (in non-JavaScript-compatibility mode). For example,
671        /(another)?(\1?)test/ matched against "hello world test". This bug was
672        introduced in release 8.13.
674    6.  Add support for 16-bit character strings (a large amount of work involving
675        many changes and refactorings).
677    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
678        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
679        from a file.
681    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
682        rounding is not applied in this particular case).
684    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
685        if they appear, or are escaped, in patterns.
687    10. Get rid of a number of -Wunused-but-set-variable warnings.
689    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
690        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
691        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
692        also returns the mark "x". This bug applied to capturing parentheses,
693        non-capturing parentheses, and atomic parentheses. It also applied to some
694        assertions.
696    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
697        information out of configure.ac instead of relying on pcre.h.generic, which
698        is not stored in the repository.
700    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
701        -lreadline.
703    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
705    15. Applied Graycode's patch to put the top-level frame on the stack rather
706        than the heap when not using the stack for recursion. This gives a
707        performance improvement in many cases when recursion is not deep.
709    16. Experimental code added to "pcretest -C" to output the stack frame size.
712    Version 8.21 12-Dec-2011
713    ------------------------
715    1.  Updating the JIT compiler.
717    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
718        are added as well.
720    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
721        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
722        calling _pcre_jit_exec. Some extra comments are added.
724    4.  (*MARK) settings inside atomic groups that do not contain any capturing
725        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
726        was introduced by change 18 for 8.20.
728    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
729        ECMA-262 standard.
731    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
732        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
733        This bug was probably introduced by change 9 of 8.13.
735    7.  While fixing 6 above, I noticed that a number of other items were being
736        incorrectly rejected as "not fixed length". This arose partly because newer
737        opcodes had not been added to the fixed-length checking code. I have (a)
738        corrected the bug and added tests for these items, and (b) arranged for an
739        error to occur if an unknown opcode is encountered while checking for fixed
740        length instead of just assuming "not fixed length". The items that were
741        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
742        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
743        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
745    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
746        being incorrectly compiled and would have given unpredicatble results.
748    9.  A possessively repeated subpattern with minimum repeat count greater than
749        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
750        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
751        the first (A) could occur when it should not.
753    10. Add a cast and remove a redundant test from the code.
755    11. JIT should use pcre_malloc/pcre_free for allocation.
757    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
758        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
759        is anything other than /usr, -L is still shown).
761    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
763    14. Perl does not support \N without a following name in a [] class; PCRE now
764        also gives an error.
766    15. If a forward reference was repeated with an upper limit of around 2000,
767        it caused the error "internal error: overran compiling workspace". The
768        maximum number of forward references (including repeats) was limited by the
769        internal workspace, and dependent on the LINK_SIZE. The code has been
770        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
771        the default depends on LINK_SIZE. There is a new upper limit (for safety)
772        of around 200,000 forward references. While doing this, I also speeded up
773        the filling in of repeated forward references.
775    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
776        incorrectly expecting the subject to contain another "a" after the start.
778    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
779        in the match, the SKIP should be ignored. This was not happening; instead
780        the SKIP was being treated as NOMATCH. For patterns such as
781        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
782        tested.
784    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
785        now much more compatible with Perl, in particular in cases where the result
786        is a non-match for a non-anchored pattern. For example, if
787        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
788        "m", where previously it did not return a name. A side effect of this
789        change is that for partial matches, the last encountered mark name is
790        returned, as for non matches. A number of tests that were previously not
791        Perl-compatible have been moved into the Perl-compatible test files. The
792        refactoring has had the pleasing side effect of removing one argument from
793        the match() function, thus reducing its stack requirements.
795    19. If the /S+ option was used in pcretest to study a pattern using JIT,
796        subsequent uses of /S (without +) incorrectly behaved like /S+.
798    21. Retrieve executable code size support for the JIT compiler and fixing
799        some warnings.
801    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
802        not work when the shorter character appeared right at the end of the
803        subject string.
805    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
806        systems.
808    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
809        output it when the /M option is used in pcretest.
811    25. The CheckMan script was not being included in the distribution. Also, added
812        an explicit "perl" to run Perl scripts from the PrepareRelease script
813        because this is reportedly needed in Windows.
815    26. If study data was being save in a file and studying had not found a set of
816        "starts with" bytes for the pattern, the data written to the file (though
817        never used) was taken from uninitialized memory and so caused valgrind to
818        complain.
820    27. Updated RunTest.bat as provided by Sheri Pierce.
822    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
824    29. Computation of memory usage for the table of capturing group names was
825        giving an unnecessarily large value.
828    Version 8.20 21-Oct-2011
829    ------------------------
831    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
832        a POSIX class. After further experiments with Perl, which convinced me that
833        Perl has bugs and confusions, a closing square bracket is no longer allowed
834        in a POSIX name. This bug also affected patterns with classes that started
835        with full stops.
837    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
838        captured substring, but while checking the failing first alternative,
839        substring 1 is temporarily captured. If the output vector supplied to
840        pcre_exec() was not big enough for this capture, the yield of the function
841        was still zero ("insufficient space for captured substrings"). This cannot
842        be totally fixed without adding another stack variable, which seems a lot
843        of expense for a edge case. However, I have improved the situation in cases
844        such as /(a)(b)x|abc/ matched against "abc", where the return code
845        indicates that fewer than the maximum number of slots in the ovector have
846        been set.
848    3.  Related to (2) above: when there are more back references in a pattern than
849        slots in the output vector, pcre_exec() uses temporary memory during
850        matching, and copies in the captures as far as possible afterwards. It was
851        using the entire output vector, but this conflicts with the specification
852        that only 2/3 is used for passing back captured substrings. Now it uses
853        only the first 2/3, for compatibility. This is, of course, another edge
854        case.
856    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
857        main code base, and can be used by building with --enable-jit. When this is
858        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
859        runtime --no-jit option is given.
861    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
862        ovector, the return from the function was zero, implying that there were
863        other matches that did not fit. The correct "exactly full" value is now
864        returned.
866    6.  If a subpattern that was called recursively or as a subroutine contained
867        (*PRUNE) or any other control that caused it to give a non-standard return,
868        invalid errors such as "Error -26 (nested recursion at the same subject
869        position)" or even infinite loops could occur.
871    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
872        computing the minimum length on reaching *ACCEPT, and so ended up with the
873        wrong value of 1 rather than 0. Further investigation indicates that
874        computing a minimum subject length in the presence of *ACCEPT is difficult
875        (think back references, subroutine calls), and so I have changed the code
876        so that no minimum is registered for a pattern that contains *ACCEPT.
878    8.  If (*THEN) was present in the first (true) branch of a conditional group,
879        it was not handled as intended. [But see 16 below.]
881    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
882        Sheri Pierce.
884    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
885        the first byte in a match must be "a".
887    11. Change 17 for 8.13 increased the recursion depth for patterns like
888        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
889        pattern contains any instances of (*THEN). If it does not, the old
890        optimizations are restored. It would be nice to do this on a per-group
891        basis, but at the moment that is not feasible.
893    12. In some environments, the output of pcretest -C is CRLF terminated. This
894        broke RunTest's code that checks for the link size. A single white space
895        character after the value is now allowed for.
897    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
898        For "fr", it uses the Windows-specific input and output files.
900    14. If (*THEN) appeared in a group that was called recursively or as a
901        subroutine, it did not work as intended. [But see next item.]
903    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
904        pattern fragments (but not containing any | characters). If A and B are
905        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
906        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
907        D. In other words, Perl considers parentheses that do not contain any |
908        characters to be part of a surrounding alternative, whereas PCRE was
909        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
910        differently. PCRE now behaves in the same way as Perl, except in the case
911        of subroutine/recursion calls such as (?1) which have in any case always
912        been different (but PCRE had them first :-).
914    16. Related to 15 above: Perl does not treat the | in a conditional group as
915        creating alternatives. Such a group is treated in the same way as an
916        ordinary group without any | characters when processing (*THEN). PCRE has
917        been changed to match Perl's behaviour.
919    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
920        RunGrepTest script failed.
922    18. Change 22 for version 13 caused atomic groups to use more stack. This is
923        inevitable for groups that contain captures, but it can lead to a lot of
924        stack use in large patterns. The old behaviour has been restored for atomic
925        groups that do not contain any capturing parentheses.
927    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
928        suppress the check for a minimum subject length at run time. (If it was
929        given to pcre_exec() or pcre_dfa_exec() it did work.)
931    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
932        fail to work when decoding hex characters in data strings in EBCDIC
933        environments.
935    21. It appears that in at least one Mac OS environment, the isxdigit() function
936        is implemented as a macro that evaluates to its argument more than once,
937        contravening the C 90 Standard (I haven't checked a later standard). There
938        was an instance in pcretest which caused it to go wrong when processing
939        \x{...} escapes in subject strings. The has been rewritten to avoid using
940        things like p++ in the argument of isxdigit().
943    Version 8.13 16-Aug-2011
944    ------------------------
946    1.  The Unicode data tables have been updated to Unicode 6.0.0.
948    2.  Two minor typos in pcre_internal.h have been fixed.
950    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
951        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
952        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
954    4.  There were a number of related bugs in the code for matching backrefences
955        caselessly in UTF-8 mode when codes for the characters concerned were
956        different numbers of bytes. For example, U+023A and U+2C65 are an upper
957        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
958        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
959        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
960        2-byte code at the end of the subject (it thought there wasn't enough data
961        left).
963    5.  Comprehensive information about what went wrong is now returned by
964        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
965        as the output vector has at least 2 elements. The offset of the start of
966        the failing character and a reason code are placed in the vector.
968    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
969        now returned is for the first byte of the failing character, instead of the
970        last byte inspected. This is an incompatible change, but I hope it is small
971        enough not to be a problem. It makes the returned offset consistent with
972        pcre_exec() and pcre_dfa_exec().
974    7.  pcretest now gives a text phrase as well as the error number when
975        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
976        failure, the offset and reason code are output.
978    8.  When \R was used with a maximizing quantifier it failed to skip backwards
979        over a \r\n pair if the subsequent match failed. Instead, it just skipped
980        back over a single character (\n). This seems wrong (because it treated the
981        two characters as a single entity when going forwards), conflicts with the
982        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
983        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
984        has been changed.
986    9.  Some internal refactoring has changed the processing so that the handling
987        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
988        time (the PCRE_DOTALL option was changed this way some time ago: version
989        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
990        which was always a bit of a fudge. It also means that there is one less
991        argument for the match() function, which reduces its stack requirements
992        slightly. This change also fixes an incompatibility with Perl: the pattern
993        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
995    10. More internal refactoring has drastically reduced the number of recursive
996        calls to match() for possessively repeated groups such as (abc)++ when
997        using pcre_exec().
999    11. While implementing 10, a number of bugs in the handling of groups were
1000        discovered and fixed:
1002        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1003        (a|)*(?1) gave a compile-time internal error.
1004        ((a|)+)+  did not notice that the outer group could match an empty string.
1005        (^a|^)+   was not marked as anchored.
1006        (.*a|.*)+ was not marked as matching at start or after a newline.
1008    12. Yet more internal refactoring has removed another argument from the match()
1009        function. Special calls to this function are now indicated by setting a
1010        value in a variable in the "match data" data block.
1012    13. Be more explicit in pcre_study() instead of relying on "default" for
1013        opcodes that mean there is no starting character; this means that when new
1014        ones are added and accidentally left out of pcre_study(), testing should
1015        pick them up.
1017    14. The -s option of pcretest has been documented for ages as being an old
1018        synonym of -m (show memory usage). I have changed it to mean "force study
1019        for every regex", that is, assume /S for every regex. This is similar to -i
1020        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1021        using it. It makes it easier to run collections of tests with and without
1022        study enabled, and thereby test pcre_study() more easily. All the standard
1023        tests are now run with and without -s (but some patterns can be marked as
1024        "never study" - see 20 below).
1026    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1027        restoration of the capturing data to the outer values was not happening
1028        correctly.
1030    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1031        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1032        pattern had matched an empty string, and so incorrectly returned a no
1033        match.
1035    17. There was optimizing code for the last branch of non-capturing parentheses,
1036        and also for the obeyed branch of a conditional subexpression, which used
1037        tail recursion to cut down on stack usage. Unfortunately, now that there is
1038        the possibility of (*THEN) occurring in these branches, tail recursion is
1039        no longer possible because the return has to be checked for (*THEN). These
1040        two optimizations have therefore been removed. [But see 8.20/11 above.]
1042    18. If a pattern containing \R was studied, it was assumed that \R always
1043        matched two bytes, thus causing the minimum subject length to be
1044        incorrectly computed because \R can also match just one byte.
1046    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1047        was incorrectly computed.
1049    20. If /S is present twice on a test pattern in pcretest input, it now
1050        *disables* studying, thereby overriding the use of -s on the command line
1051        (see 14 above). This is necessary for one or two tests to keep the output
1052        identical in both cases.
1054    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1055        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1057    22. When an atomic group that contained a capturing parenthesis was
1058        successfully matched, but the branch in which it appeared failed, the
1059        capturing was not being forgotten if a higher numbered group was later
1060        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1061        group 1 to "a", when in fact it should be unset. This applied to multi-
1062        branched capturing and non-capturing groups, repeated or not, and also to
1063        positive assertions (capturing in negative assertions does not happen
1064        in PCRE) and also to nested atomic groups.
1066    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1067        subject after a captured substring, to make it easier to tell which of a
1068        number of identical substrings has been captured.
1070    24. The way atomic groups are processed by pcre_exec() has been changed so that
1071        if they are repeated, backtracking one repetition now resets captured
1072        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1073        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1074        "aaa". Previously, it would have been "a". As part of this code
1075        refactoring, the way recursive calls are handled has also been changed.
1077    25. If an assertion condition captured any substrings, they were not passed
1078        back unless some other capturing happened later. For example, if
1079        (?(?=(a))a) was matched against "a", no capturing was returned.
1081    26. When studying a pattern that contained subroutine calls or assertions,
1082        the code for finding the minimum length of a possible match was handling
1083        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1084        group 1 called group 2 while simultaneously a separate group 2 called group
1085        1). A stack overflow occurred in this case. I have fixed this by limiting
1086        the recursion depth to 10.
1088    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1089        Fortmann. This supports explicit test numbers on the command line, and has
1090        argument validation and error reporting.
1092    28. An instance of \X with an unlimited repeat could fail if at any point the
1093        first character it looked at was a mark character.
1095    29. Some minor code refactoring concerning Unicode properties and scripts
1096        should reduce the stack requirement of match() slightly.
1098    30. Added the '=' option to pcretest to check the setting of unused capturing
1099        slots at the end of the pattern, which are documented as being -1, but are
1100        not included in the return count.
1102    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1103        compiled something random. Now it gives a compile-time error (as does
1104        Perl).
1106    32. A *MARK encountered during the processing of a positive assertion is now
1107        recorded and passed back (compatible with Perl).
1109    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1110        had alternative anchored branches, the search for a second match in a line
1111        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1112        matched the line "0102" twice. The same bug affected patterns that started
1113        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1114        twice.
1116    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1117        does, and because of capturing effects, quantifying parenthesized
1118        assertions may at times be useful. Quantifiers are now allowed for
1119        parenthesized assertions.
1121    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1123    36. \g was being checked for fancy things in a character class, when it should
1124        just be a literal "g".
1126    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1127        appearance of a nested POSIX class supersedes an apparent external class.
1128        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1129        unescaped square brackets may also appear as part of class names. For
1130        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1131        more like Perl. (But see 8.20/1 above.)
1133    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1134        was because it thought it was \N{name}, which is not supported).
1136    39. Add minix to OS list not supporting the -S option in pcretest.
1138    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1139        cannot analyze patterns in sufficient detail to catch mutual recursions
1140        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1141        subgroup is called recursively as a subpattern for a second time at the
1142        same position in the subject string. In previous releases this might have
1143        been caught by the recursion limit, or it might have run out of stack.
1145    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1146        happen only once. PCRE was, however incorrectly giving a compile time error
1147        "recursive call could loop indefinitely" because it cannot analyze the
1148        pattern in sufficient detail. The compile time test no longer happens when
1149        PCRE is compiling a conditional subpattern, but actual runaway loops are
1150        now caught at runtime (see 40 above).
1152    42. It seems that Perl allows any characters other than a closing parenthesis
1153        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1154        has been changed to be the same.
1156    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1157        as not to get warnings when autogen.sh is called. Also changed
1158        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1160    44. To help people who use pcregrep to scan files containing exceedingly long
1161        lines, the following changes have been made:
1163        (a) The default value of the buffer size parameter has been increased from
1164            8K to 20K. (The actual buffer used is three times this size.)
1166        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1167            PCRE is built.
1169        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1170            to be set at run time.
1172        (d) Numerical values in pcregrep options can be followed by K or M, for
1173            example --buffer-size=50K.
1175        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1176            given and the return code is set to 2.
1178    45. Add a pointer to the latest mark to the callout data block.
1180    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1181        partial match of an empty string instead of no match. This was specific to
1182        the use of ".".
1184    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1185        complete match instead of a partial match. This bug was dependent on both
1186        the PCRE_UTF8 and PCRE_DOTALL options being set.
1188    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1189        starting byte set, because \b was not being ignored.
1192    Version 8.12 15-Jan-2011
1193    ------------------------
1195    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1196        checks for such things as part of the documentation building process.
1198    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1199        --match-limit and --recursion-limit options (added for 8.11). In
1200        particular, this made one of the standard tests fail. (The integer value
1201        went into the wrong half of a long int.)
1203    3.  If the --colour option was given to pcregrep with -v (invert match), it
1204        did strange things, either producing crazy output, or crashing. It should,
1205        of course, ignore a request for colour when reporting lines that do not
1206        match.
1208    4.  Another pcregrep bug caused similar problems if --colour was specified with
1209        -M (multiline) and the pattern match finished with a line ending.
1211    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1212        matched in multiline mode, the following line was shown as part of the
1213        match. This seems wrong, so I have changed it.
1215    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1216        the check for further matches in the same line (so they could be coloured)
1217        to overrun the end of the current line. If another match was found, it was
1218        incorrectly shown (and then shown again when found in the next line).
1220    7.  If pcregrep was compiled under Windows, there was a reference to the
1221        function pcregrep_exit() before it was defined. I am assuming this was
1222        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1223        reported by a user. I've moved the definition above the reference.
1226    Version 8.11 10-Dec-2010
1227    ------------------------
1229    1.  (*THEN) was not working properly if there were untried alternatives prior
1230        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1231        backtracked to try for "b" instead of moving to the next alternative branch
1232        at the same level (in this case, to look for "c"). The Perl documentation
1233        is clear that when (*THEN) is backtracked onto, it goes to the "next
1234        alternative in the innermost enclosing group".
1236    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1237        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1238        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1239        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1240        (*THEN).
1242    3.  If \s appeared in a character class, it removed the VT character from
1243        the class, even if it had been included by some previous item, for example
1244        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1245        of \s, but is part of the POSIX "space" class.)
1247    4.  A partial match never returns an empty string (because you can always
1248        match an empty string at the end of the subject); however the checking for
1249        an empty string was starting at the "start of match" point. This has been
1250        changed to the "earliest inspected character" point, because the returned
1251        data for a partial match starts at this character. This means that, for
1252        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1253        (previously it gave "no match").
1255    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1256        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1257        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1258        has an implication that the given string is incomplete (because a partial
1259        match is preferred over a full match). For this reason, these items now
1260        give a partial match in this situation. [Aside: previously, the one case
1261        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1262        match rather than a full match, which was wrong by the old rules, but is
1263        now correct.]
1265    6.  There was a bug in the handling of #-introduced comments, recognized when
1266        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1267        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1268        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1269        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1270        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1271        places in pcre_compile().
1273    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1274        comments when looking ahead for named forward references to subpatterns,
1275        the only newline sequence it recognized was NL. It now handles newlines
1276        according to the set newline convention.
1278    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1279        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1280        cater for a lack of strerror(). These oversights have been fixed.
1282    9.  Added --match-limit and --recursion-limit to pcregrep.
1284    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1286    11. When the -o option was used, pcregrep was setting a return code of 1, even
1287        when matches were found, and --line-buffered was not being honoured.
1289    12. Added an optional parentheses number to the -o and --only-matching options
1290        of pcregrep.
1292    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1293        can match an empty string. The code to do it in pcretest and pcredemo
1294        needed fixing:
1296        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1297            only one byte after an empty string match just before CRLF (this case
1298            just got forgotten; "any" and "anycrlf" were OK).
1300        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1301            mode when an empty string match preceded an ASCII character followed by
1302            a non-ASCII character. (The code for advancing by one character rather
1303            than one byte was nonsense.)
1305        (c) The pcredemo.c sample program did not have any code at all to handle
1306            the cases when CRLF is a valid newline sequence.
1308    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1309        as a starting offset was within the subject string. There is now a new
1310        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1311        negative or greater than the length of the string. In order to test this,
1312        pcretest is extended to allow the setting of negative starting offsets.
1314    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1315        starting offset points to the beginning of a UTF-8 character was
1316        unnecessarily clumsy. I tidied it up.
1318    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1319        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1321    17. Nobody had reported that the --include_dir option, which was added in
1322        release 7.7 should have been called --include-dir (hyphen, not underscore)
1323        for compatibility with GNU grep. I have changed it to --include-dir, but
1324        left --include_dir as an undocumented synonym, and the same for
1325        --exclude-dir, though that is not available in GNU grep, at least as of
1326        release 2.5.4.
1328    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1329        characters from a string of bytes) have been redefined so as not to use
1330        loops, in order to improve performance in some environments. At the same
1331        time, I abstracted some of the common code into auxiliary macros to save
1332        repetition (this should not affect the compiled code).
1334    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1335        compile-time error is now given if \c is not followed by an ASCII
1336        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1337        different, and any byte value is allowed.)
1339    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1340        START_OPTIMIZE option, which is now allowed at compile time - but just
1341        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1342        to pcregrep and other applications that have no direct access to PCRE
1343        options. The new /Y option in pcretest sets this option when calling
1344        pcre_compile().
1346    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1347        back references. Groups containing recursive back references were forced to
1348        be atomic by that change, but in the case of named groups, the amount of
1349        memory required was incorrectly computed, leading to "Failed: internal
1350        error: code overflow". This has been fixed.
1352    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1353        pcretest.c, to avoid build problems in some Borland environments.
1356    Version 8.10 25-Jun-2010
1357    ------------------------
1359    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1360        THEN.
1362    2.  (*ACCEPT) was not working when inside an atomic group.
1364    3.  Inside a character class, \B is treated as a literal by default, but
1365        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1366        causes the error). The code is unchanged, but I tidied the documentation.
1368    4.  Inside a character class, PCRE always treated \R and \X as literals,
1369        whereas Perl faults them if its -w option is set. I have changed PCRE so
1370        that it faults them when PCRE_EXTRA is set.
1372    5.  Added support for \N, which always matches any character other than
1373        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1375    6.  When compiling pcregrep with newer versions of gcc which may have
1376        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1377        declared with attribute warn_unused_result" were given. Just casting the
1378        result to (void) does not stop the warnings; a more elaborate fudge is
1379        needed. I've used a macro to implement this.
1381    7.  Minor change to pcretest.c to avoid a compiler warning.
1383    8.  Added four artifical Unicode properties to help with an option to make
1384        \s etc use properties (see next item). The new properties are: Xan
1385        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1387    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1388        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1389        this option. Modified pcretest to add /W to test this facility. Added
1390        REG_UCP to make it available via the POSIX interface.
1392    10. Added --line-buffered to pcregrep.
1394    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1395        studied, and the match started with a letter with a code point greater than
1396        127 whose first byte was different to the first byte of the other case of
1397        the letter, the other case of this starting letter was not recognized
1398        (#976).
1400    12. If a pattern that was studied started with a repeated Unicode property
1401        test, for example, \p{Nd}+, there was the theoretical possibility of
1402        setting up an incorrect bitmap of starting bytes, but fortunately it could
1403        not have actually happened in practice until change 8 above was made (it
1404        added property types that matched character-matching opcodes).
1406    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1407        possible starting bytes for non-anchored patterns.
1409    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1410        \R, and also a number of cases that involve Unicode properties, both
1411        explicit and implicit when PCRE_UCP is set.
1413    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1414        input, it could crash or give wrong results if characters with values
1415        greater than 0xc0 were present in the subject string. (Detail: it assumed
1416        UTF-8 input when processing these items.)
1418    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1419        size_t is 64-bit (#991).
1421    17. Added a check for running out of memory when PCRE is compiled with
1422        --disable-stack-for-recursion (#990).
1424    18. If the last data line in a file for pcretest does not have a newline on
1425        the end, a newline was missing in the output.
1427    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1428        less than 128) in its various bitmaps. However, there is a facility for
1429        generating tables according to the current locale when PCRE is compiled. It
1430        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1431        characters, are recognized by isspace() and therefore were getting set in
1432        these tables, and indeed these tables seem to approximate to ISO 8859. This
1433        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1434        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1435        which of course cannot start UTF-8 characters. I have changed the code so
1436        that only real ASCII characters (less than 128) and the correct starting
1437        bytes for UTF-8 encodings are set for characters greater than 127 when in
1438        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1439        altogether.)
1441    20. Added the /T option to pcretest so as to be able to run tests with non-
1442        standard character tables, thus making it possible to include the tests
1443        used for 19 above in the standard set of tests.
1445    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1446        reference to a subpattern the other side of a comment that contains an
1447        opening parenthesis caused either an internal compiling error, or a
1448        reference to the wrong subpattern.
1451    Version 8.02 19-Mar-2010
1452    ------------------------
1454    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1456    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1457        configured.
1459    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1460        original author of that file, following a query about its status.
1462    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1463        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1465    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1466        quantifier applied to a forward-referencing subroutine call, could compile
1467        incorrect code or give the error "internal error: previously-checked
1468        referenced subpattern not found".
1470    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1471        variables to point to external functions. For these systems, therefore,
1472        pcre_malloc etc. are now initialized to local functions that call the
1473        relevant global functions.
1475    7.  There were two entries missing in the vectors called coptable and poptable
1476        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1477        I've fixed the data, and added a kludgy way of testing at compile time that
1478        the lengths are correct (equal to the number of opcodes).
1480    8.  Following on from 7, I added a similar kludge to check the length of the
1481        eint vector in pcreposix.c.
1483    9.  Error texts for pcre_compile() are held as one long string to avoid too
1484        much relocation at load time. To find a text, the string is searched,
1485        counting zeros. There was no check for running off the end of the string,
1486        which could happen if a new error number was added without updating the
1487        string.
1489    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1491    11. \K was not working if it appeared in an atomic group or in a group that
1492        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1493        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1494        the assertion is positive, but not if it is negative.
1496    12. Change 11 fortuitously reduced the size of the stack frame used in the
1497        "match()" function of pcre_exec.c by one pointer. Forthcoming
1498        implementation of support for (*MARK) will need an extra pointer on the
1499        stack; I have reserved it now, so that the stack frame size does not
1500        decrease.
1502    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1503        item in branch that calls a recursion is a subroutine call - as in the
1504        second branch in the above example - was incorrectly given the compile-
1505        time error "recursive call could loop indefinitely" because pcre_compile()
1506        was not correctly checking the subroutine for matching a non-empty string.
1508    14. The checks for overrunning compiling workspace could trigger after an
1509        overrun had occurred. This is a "should never occur" error, but it can be
1510        triggered by pathological patterns such as hundreds of nested parentheses.
1511        The checks now trigger 100 bytes before the end of the workspace.
1513    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1516    Version 8.01 19-Jan-2010
1517    ------------------------
1519  1.  If a pattern contained a conditional subpattern with only one branch (in  1.  If a pattern contained a conditional subpattern with only one branch (in
1520      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1521      computed the wrong minimum data length (which is of course zero for such      computed the wrong minimum data length (which is of course zero for such
1522      subpatterns).      subpatterns). This could cause incorrect "no match" results.
1524  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1525      the pattern is reset in the first branch, pcre_compile() failed with      the pattern is reset in the first branch, pcre_compile() failed with
# Line 61  Version 8.01 06-Jan-10 Line 1573  Version 8.01 06-Jan-10
1573      custom one, because of the following reported problem in Windows:      custom one, because of the following reported problem in Windows:
1575        - libbz2 uses the Pascal calling convention (WINAPI) for the functions        - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1576          under Win32.            under Win32.
1577        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1578          therefore missing the function definition.            therefore missing the function definition.
1579        - The compiler thus generates a "C" signature for the test function.        - The compiler thus generates a "C" signature for the test function.
1580        - The linker fails to find the "C" function.        - The linker fails to find the "C" function.
1581        - PCRE fails to configure if asked to do so against libbz2.        - PCRE fails to configure if asked to do so against libbz2.
# Line 113  Version 8.01 06-Jan-10 Line 1625  Version 8.01 06-Jan-10
1625      equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for      equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1626      instance, but it only takes 2 args instead of 3!"      instance, but it only takes 2 args instead of 3!"
1628    18. A subtle bug concerned with back references has been fixed by a change of
1629        specification, with a corresponding code fix. A pattern such as
1630        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1631        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1632        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1633        same bug. Such groups have to be quantified to be useful, or contained
1634        inside another quantified group. (If there's no repetition, the reference
1635        can never match.) The problem arises because, having left the group and
1636        moved on to the rest of the pattern, a later failure that backtracks into
1637        the group uses the captured value from the final iteration of the group
1638        rather than the correct earlier one. I have fixed this in PCRE by forcing
1639        any group that contains a reference to itself to be an atomic group; that
1640        is, there cannot be any backtracking into it once it has completed. This is
1641        similar to recursive and subroutine calls.
1644  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09
1645  ----------------------  ----------------------
# Line 312  Version 7.9 11-Apr-09 Line 1839  Version 7.9 11-Apr-09
1839  7.  A pattern that could match an empty string could cause pcregrep to loop; it  7.  A pattern that could match an empty string could cause pcregrep to loop; it
1840      doesn't make sense to accept an empty string match in pcregrep, so I have      doesn't make sense to accept an empty string match in pcregrep, so I have
1841      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1842      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1843        8.33.]
1845  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1846      start or after a newline", because the conditional assertion was not being      start or after a newline", because the conditional assertion was not being
# Line 555  Version 7.7 07-May-08 Line 2083  Version 7.7 07-May-08
2083      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2084      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2085      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2086      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2087      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2088      was subsequently set up correctly.)      was subsequently set up correctly.)

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