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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 30-Apr-2011  Version 8.34 xx-xxxx-201x
5    --------------------------
6    
7    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8        executable memory. Patch inspired by Carsten Klein.
9    
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.
17    
18    3.  Make a small performance improvement in strlen16() and strlen32() in
19        pcretest.
20    
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.
24    
25    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
26    
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.
34    
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.
37    
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.
40    
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:
44    
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.
49    
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.
54    
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.
60    
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.
63    
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.
66    
67    13. Added the -T and -TM options to pcretest.
68    
69    
70    Version 8.33 28-May-2013
71    ------------------------
72    
73    1.  Added 'U' to some constants that are compared to unsigned integers, to
74        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
75        variables that are added to signed variables, to ensure the result is
76        signed and can be negated.
77    
78    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
79        CMake config files.
80    
81    3.  Revise the creation of config.h.generic so that all boolean macros are
82        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
83        overriding via -D on the command line possible.
84    
85    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
86        to unsigned int is reported to make a quite noticeable speed difference in
87        a specific Windows environment. Testing on Linux did also appear to show
88        some benefit (and it is clearly not harmful). Also fixed the definition of
89        Xop which should be unsigned.
90    
91    5.  Related to (4), changing the definition of the intermediate variable cc
92        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
93        improvements.
94    
95    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
96        unnecessary spaces.
97    
98    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
99        and later.
100    
101    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
102    
103    9.  Optimizing fast_forward_start_bits in JIT.
104    
105    10. Adding support for callouts in JIT, and fixing some issues revealed
106        during this work. Namely:
107    
108        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
109    
110        (b) Minimum length was not checked before the matching is started.
111    
112    11. The value of capture_last that is passed to callouts was incorrect in some
113        cases when there was a capture on one path that was subsequently abandoned
114        after a backtrack. Also, the capture_last value is now reset after a
115        recursion, since all captures are also reset in this case.
116    
117    12. The interpreter no longer returns the "too many substrings" error in the
118        case when an overflowing capture is in a branch that is subsequently
119        abandoned after a backtrack.
120    
121    13. In the pathological case when an offset vector of size 2 is used, pcretest
122        now prints out the matched string after a yield of 0 or 1.
123    
124    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
125        Only supported by the JIT compiler at the moment.
126    
127    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
128    
129    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
130        offset of the starting point of the matching process, provided the offsets
131        vector is large enough.
132    
133    17. The \A escape now records a lookbehind value of 1, though its execution
134        does not actually inspect the previous character. This is to ensure that,
135        in partial multi-segment matching, at least one character from the old
136        segment is retained when a new segment is processed. Otherwise, if there
137        are no lookbehinds in the pattern, \A might match incorrectly at the start
138        of a new segment.
139    
140    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
141    
142    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
143        gives some modest performance improvement in 8-bit mode.
144    
145    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
146        be expressed in certain programming languages using Universal Character
147        Names.
148    
149    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
150        which points out that "non characters" are not "characters that may not
151        appear in Unicode strings" but rather "characters that are reserved for
152        internal use and have only local meaning".
153    
154    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
155        there was a conditional group that depended on an assertion, if the
156        assertion was false, the callout that immediately followed the alternation
157        in the condition was skipped when pcre_exec() was used for matching.
158    
159    23. Allow an explicit callout to be inserted before an assertion that is the
160        condition for a conditional group, for compatibility with automatic
161        callouts, which always insert a callout at this point.
162    
163    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
164        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
165    
166    25. (*PRUNE) is now supported by the JIT compiler.
167    
168    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
169    
170    27. Fix the case where there are two or more SKIPs with arguments that may be
171        ignored.
172    
173    28. (*SKIP) is now supported by the JIT compiler.
174    
175    29. (*THEN) is now supported by the JIT compiler.
176    
177    30. Update RunTest with additional test selector options.
178    
179    31. The way PCRE handles backtracking verbs has been changed in two ways.
180    
181        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
182        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
183        backtracking. In some cases this makes it more Perl-compatible, but Perl's
184        rather obscure rules do not always do the same thing.
185    
186        (2) Previously, backtracking verbs were confined within assertions. This is
187        no longer the case for positive assertions, except for (*ACCEPT). Again,
188        this sometimes improves Perl compatibility, and sometimes does not.
189    
190    32. A number of tests that were in test 2 because Perl did things differently
191        have been moved to test 1, because either Perl or PCRE has changed, and
192        these tests are now compatible.
193    
194    32. Backtracking control verbs are now handled in the same way in JIT and
195        interpreter.
196    
197    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
198        contained a forward subroutine reference caused a compile error.
199    
200    34. Auto-detect and optimize limited repetitions in JIT.
201    
202    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
203        blocking (*UTF) etc.
204    
205    36. In the interpreter, maximizing pattern repetitions for characters and
206        character types now use tail recursion, which reduces stack usage.
207    
208    37. The value of the max lookbehind was not correctly preserved if a compiled
209        and saved regex was reloaded on a host of different endianness.
210    
211    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
212        of the compiled pattern block, expand the flags field from 16 to 32 bits
213        because it was almost full.
214    
215    39. Try madvise first before posix_madvise.
216    
217    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
218        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
219        original change locked out all matches of empty strings. This has been
220        changed so that one match of an empty string per line is recognized.
221        Subsequent searches on the same line (for colouring or for --only-matching,
222        for example) do not recognize empty strings.
223    
224    41. Applied a user patch to fix a number of spelling mistakes in comments.
225    
226    42. Data lines longer than 65536 caused pcretest to crash.
227    
228    43. Clarified the data type for length and startoffset arguments for pcre_exec
229        and pcre_dfa_exec in the function-specific man pages, where they were
230        explicitly stated to be in bytes, never having been updated. I also added
231        some clarification to the pcreapi man page.
232    
233    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
234        a segmentation fault.
235    
236    
237    Version 8.32 30-November-2012
238    -----------------------------
239    
240    1.  Improved JIT compiler optimizations for first character search and single
241        character iterators.
242    
243    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
244        Patch by Daniel Richard G.
245    
246    3.  Single character iterator optimizations in the JIT compiler.
247    
248    4.  Improved JIT compiler optimizations for character ranges.
249    
250    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
251        Reported by Giuseppe D'Angelo.
252    
253    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
254        of a line, was being set incorrectly in cases where .* appeared inside
255        atomic brackets at the start of a pattern, or where there was a subsequent
256        *PRUNE or *SKIP.
257    
258    7.  Improved instruction cache flush for POWER/PowerPC.
259        Patch by Daniel Richard G.
260    
261    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
262        grep:
263    
264        (a) There is now no limit to the number of patterns to be matched.
265    
266        (b) An error is given if a pattern is too long.
267    
268        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
269            are now supported.
270    
271        (d) --exclude-from and --include-from (multiple use) have been added.
272    
273        (e) Exclusions and inclusions now apply to all files and directories, not
274            just to those obtained from scanning a directory recursively.
275    
276        (f) Multiple uses of -f and --file-list are now supported.
277    
278        (g) In a Windows environment, the default for -d has been changed from
279            "read" (the GNU grep default) to "skip", because otherwise the presence
280            of a directory in the file list provokes an error.
281    
282        (h) The documentation has been revised and clarified in places.
283    
284    9.  Improve the matching speed of capturing brackets.
285    
286    10. Changed the meaning of \X so that it now matches a Unicode extended
287        grapheme cluster.
288    
289    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
290        out POSIX threads when JIT support is configured.
291    
292    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
293    
294    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
295        structure could go wrong in environments where size_t is not the same size
296        as int.
297    
298    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
299        set.
300    
301    15. The EBCDIC support had decayed; later updates to the code had included
302        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
303        general tidy up of EBCDIC-related issues, and the documentation was also
304        not quite right. There is now a test that can be run on ASCII systems to
305        check some of the EBCDIC-related things (but is it not a full test).
306    
307    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
308        in a small tidy to the code.
309    
310    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
311    
312    18. If the --only-matching (-o) option in pcregrep is specified multiple
313        times, each one causes appropriate output. For example, -o1 -o2 outputs the
314        substrings matched by the 1st and 2nd capturing parentheses. A separating
315        string can be specified by --om-separator (default empty).
316    
317    19. Improving the first n character searches.
318    
319    20. Turn case lists for horizontal and vertical white space into macros so that
320        they are defined only once.
321    
322    21. This set of changes together give more compatible Unicode case-folding
323        behaviour for characters that have more than one other case when UCP
324        support is available.
325    
326        (a) The Unicode property table now has offsets into a new table of sets of
327            three or more characters that are case-equivalent. The MultiStage2.py
328            script that generates these tables (the pcre_ucd.c file) now scans
329            CaseFolding.txt instead of UnicodeData.txt for character case
330            information.
331    
332        (b) The code for adding characters or ranges of characters to a character
333            class has been abstracted into a generalized function that also handles
334            case-independence. In UTF-mode with UCP support, this uses the new data
335            to handle characters with more than one other case.
336    
337        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
338            whose other case is greater than 256 are now correctly matched
339            caselessly. Previously, the high codepoint matched the low one, but not
340            vice versa.
341    
342        (d) The processing of \h, \H, \v, and \ in character classes now makes use
343            of the new class addition function, using character lists defined as
344            macros alongside the case definitions of 20 above.
345    
346        (e) Caseless back references now work with characters that have more than
347            one other case.
348    
349        (f) General caseless matching of characters with more than one other case
350            is supported.
351    
352    22. Unicode character properties were updated from Unicode 6.2.0
353    
354    23. Improved CMake support under Windows. Patch by Daniel Richard G.
355    
356    24. Add support for 32-bit character strings, and UTF-32
357    
358    25. Major JIT compiler update (code refactoring and bugfixing).
359        Experimental Sparc 32 support is added.
360    
361    26. Applied a modified version of Daniel Richard G's patch to create
362        pcre.h.generic and config.h.generic by "make" instead of in the
363        PrepareRelease script.
364    
365    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
366        pcre_compile.c when checking for a zero character.
367    
368    28. Introducing a native interface for JIT. Through this interface, the compiled
369        machine code can be directly executed. The purpose of this interface is to
370        provide fast pattern matching, so several sanity checks are not performed.
371        However, feature tests are still performed. The new interface provides
372        1.4x speedup compared to the old one.
373    
374    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
375        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
376        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
377    
378    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
379        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
380        the "old" RFC 2279). Instead, it ended up passing a negative length to
381        pcre_exec().
382    
383    31. Add support for GCC's visibility feature to hide internal functions.
384    
385    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
386        "unknown -C option" after outputting 0 or 1.
387    
388    33. There is now support for generating a code coverage report for the test
389        suite in environments where gcc is the compiler and lcov is installed. This
390        is mainly for the benefit of the developers.
391    
392    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
393        unaddressable using valgrind annotations, allowing valgrind to detect
394        invalid memory accesses. This is mainly for the benefit of the developers.
395    
396    25. (*UTF) can now be used to start a pattern in any of the three libraries.
397    
398    26. Give configure error if --enable-cpp but no C++ compiler found.
399    
400    
401    Version 8.31 06-July-2012
402    -------------------------
403    
404    1.  Fixing a wrong JIT test case and some compiler warnings.
405    
406    2.  Removed a bashism from the RunTest script.
407    
408    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
409        to unsigned type, result still unsigned" that was given by an MS compiler
410        on encountering the code "-sizeof(xxx)".
411    
412    4.  Partial matching support is added to the JIT compiler.
413    
414    5.  Fixed several bugs concerned with partial matching of items that consist
415        of more than one character:
416    
417        (a) /^(..)\1/ did not partially match "aba" because checking references was
418            done on an "all or nothing" basis. This also applied to repeated
419            references.
420    
421        (b) \R did not give a hard partial match if \r was found at the end of the
422            subject.
423    
424        (c) \X did not give a hard partial match after matching one or more
425            characters at the end of the subject.
426    
427        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
428            a partial match for the string "\r".
429    
430        (e) When newline was set to CRLF, the metacharacter "." did not recognize
431            a partial match for a CR character at the end of the subject string.
432    
433    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
434        running pcretest, the text "(JIT)" added to the output whenever JIT is
435        actually used to run the match.
436    
437    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
438        or /S+[+] with a digit between 1 and 7.
439    
440    8.  OP_NOT now supports any UTF character not just single-byte ones.
441    
442    9.  (*MARK) control verb is now supported by the JIT compiler.
443    
444    10. The command "./RunTest list" lists the available tests without actually
445        running any of them. (Because I keep forgetting what they all are.)
446    
447    11. Add PCRE_INFO_MAXLOOKBEHIND.
448    
449    12. Applied a (slightly modified) user-supplied patch that improves performance
450        when the heap is used for recursion (compiled with --disable-stack-for-
451        recursion). Instead of malloc and free for each heap frame each time a
452        logical recursion happens, frames are retained on a chain and re-used where
453        possible. This sometimes gives as much as 30% improvement.
454    
455    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
456        call.
457    
458    14. As documented, (*COMMIT) is now confined to within a positive assertion.
459    
460    15. It is now possible to link pcretest with libedit as an alternative to
461        libreadline.
462    
463    16. (*COMMIT) control verb is now supported by the JIT compiler.
464    
465    17. The Unicode data tables have been updated to Unicode 6.1.0.
466    
467    18. Added --file-list option to pcregrep.
468    
469    19. Added binary file support to pcregrep, including the -a, --binary-files,
470        -I, and --text options.
471    
472    20. The madvise function is renamed for posix_madvise for QNX compatibility
473        reasons. Fixed by Giuseppe D'Angelo.
474    
475    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
476    
477    22. Changed the option for creating symbolic links for 16-bit man pages from
478        -s to -sf so that re-installing does not cause issues.
479    
480    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
481    
482    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
483        matches in certain environments (the workspace was not being correctly
484        retained). Also added to pcre_dfa_exec() a simple plausibility check on
485        some of the workspace data at the beginning of a restart.
486    
487    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
488        was not doing so when it should - probably a typo introduced by SVN 528
489        (change 8.10/14).
490    
491    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
492        \w+ when the character tables indicated that \x{c4} was a word character.
493        There were several related cases, all because the tests for doing a table
494        lookup were testing for characters less than 127 instead of 255.
495    
496    27. If a pattern contains capturing parentheses that are not used in a match,
497        their slots in the ovector are set to -1. For those that are higher than
498        any matched groups, this happens at the end of processing. In the case when
499        there were back references that the ovector was too small to contain
500        (causing temporary malloc'd memory to be used during matching), and the
501        highest capturing number was not used, memory off the end of the ovector
502        was incorrectly being set to -1. (It was using the size of the temporary
503        memory instead of the true size.)
504    
505    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
506        ovector size, it uses memory at the end of the block that it has got.
507    
508    29. Check for an overlong MARK name and give an error at compile time. The
509        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
510    
511    30. JIT compiler update.
512    
513    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
514        Rill for the patch.
515    
516    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
517    
518    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
519    
520    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
521        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
522        was enabled.
523    
524    35. Improve JIT code generation for greedy plus quantifier.
525    
526    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
527        1 to "aa" instead of to an empty string. The bug affected repeated groups
528        that could potentially match an empty string.
529    
530    37. Optimizing single character iterators in JIT.
531    
532    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
533        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
534        codepoints that are too big for the mode are faulted, and in a UTF mode,
535        disallowed codepoints are also faulted.
536    
537    39. If PCRE was compiled with UTF support, in three places in the DFA
538        matcher there was code that should only have been obeyed in UTF mode, but
539        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
540        processing when bytes with values greater than 127 were present. In 16-bit
541        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
542        both cases the values are those that cannot be the first data item in a UTF
543        character. The three items that might have provoked this were recursions,
544        possessively repeated groups, and atomic groups.
545    
546    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
547        and pcregrep, because some OS require shared objects to be explicitly
548        passed to ld, causing the link step to fail if they are not.
549    
550    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
551        mode, patterns that started with \h* or \R* might be incorrectly matched.
552    
553    
554    Version 8.30 04-February-2012
555    -----------------------------
556    
557    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
558        name is defined in ctype.h.
559    
560    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
561        only in quite long subpatterns.
562    
563    3.  Removed the function pcre_info(), which has been obsolete and deprecated
564        since it was replaced by pcre_fullinfo() in February 2000.
565    
566    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
567        match a (*MARK), and the match failed at the start of the subject, a
568        reference to memory before the start of the subject could occur. This bug
569        was introduced by fix 17 of release 8.21.
570    
571    5.  A reference to an unset group with zero minimum repetition was giving
572        totally wrong answers (in non-JavaScript-compatibility mode). For example,
573        /(another)?(\1?)test/ matched against "hello world test". This bug was
574        introduced in release 8.13.
575    
576    6.  Add support for 16-bit character strings (a large amount of work involving
577        many changes and refactorings).
578    
579    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
580        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
581        from a file.
582    
583    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
584        rounding is not applied in this particular case).
585    
586    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
587        if they appear, or are escaped, in patterns.
588    
589    10. Get rid of a number of -Wunused-but-set-variable warnings.
590    
591    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
592        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
593        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
594        also returns the mark "x". This bug applied to capturing parentheses,
595        non-capturing parentheses, and atomic parentheses. It also applied to some
596        assertions.
597    
598    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
599        information out of configure.ac instead of relying on pcre.h.generic, which
600        is not stored in the repository.
601    
602    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
603        -lreadline.
604    
605    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
606    
607    15. Applied Graycode's patch to put the top-level frame on the stack rather
608        than the heap when not using the stack for recursion. This gives a
609        performance improvement in many cases when recursion is not deep.
610    
611    16. Experimental code added to "pcretest -C" to output the stack frame size.
612    
613    
614    Version 8.21 12-Dec-2011
615    ------------------------
616    
617    1.  Updating the JIT compiler.
618    
619    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
620        are added as well.
621    
622    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
623        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
624        calling _pcre_jit_exec. Some extra comments are added.
625    
626    4.  (*MARK) settings inside atomic groups that do not contain any capturing
627        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
628        was introduced by change 18 for 8.20.
629    
630    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
631        ECMA-262 standard.
632    
633    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
634        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
635        This bug was probably introduced by change 9 of 8.13.
636    
637    7.  While fixing 6 above, I noticed that a number of other items were being
638        incorrectly rejected as "not fixed length". This arose partly because newer
639        opcodes had not been added to the fixed-length checking code. I have (a)
640        corrected the bug and added tests for these items, and (b) arranged for an
641        error to occur if an unknown opcode is encountered while checking for fixed
642        length instead of just assuming "not fixed length". The items that were
643        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
644        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
645        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
646    
647    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
648        being incorrectly compiled and would have given unpredicatble results.
649    
650    9.  A possessively repeated subpattern with minimum repeat count greater than
651        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
652        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
653        the first (A) could occur when it should not.
654    
655    10. Add a cast and remove a redundant test from the code.
656    
657    11. JIT should use pcre_malloc/pcre_free for allocation.
658    
659    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
660        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
661        is anything other than /usr, -L is still shown).
662    
663    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
664    
665    14. Perl does not support \N without a following name in a [] class; PCRE now
666        also gives an error.
667    
668    15. If a forward reference was repeated with an upper limit of around 2000,
669        it caused the error "internal error: overran compiling workspace". The
670        maximum number of forward references (including repeats) was limited by the
671        internal workspace, and dependent on the LINK_SIZE. The code has been
672        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
673        the default depends on LINK_SIZE. There is a new upper limit (for safety)
674        of around 200,000 forward references. While doing this, I also speeded up
675        the filling in of repeated forward references.
676    
677    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
678        incorrectly expecting the subject to contain another "a" after the start.
679    
680    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
681        in the match, the SKIP should be ignored. This was not happening; instead
682        the SKIP was being treated as NOMATCH. For patterns such as
683        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
684        tested.
685    
686    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
687        now much more compatible with Perl, in particular in cases where the result
688        is a non-match for a non-anchored pattern. For example, if
689        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
690        "m", where previously it did not return a name. A side effect of this
691        change is that for partial matches, the last encountered mark name is
692        returned, as for non matches. A number of tests that were previously not
693        Perl-compatible have been moved into the Perl-compatible test files. The
694        refactoring has had the pleasing side effect of removing one argument from
695        the match() function, thus reducing its stack requirements.
696    
697    19. If the /S+ option was used in pcretest to study a pattern using JIT,
698        subsequent uses of /S (without +) incorrectly behaved like /S+.
699    
700    21. Retrieve executable code size support for the JIT compiler and fixing
701        some warnings.
702    
703    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
704        not work when the shorter character appeared right at the end of the
705        subject string.
706    
707    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
708        systems.
709    
710    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
711        output it when the /M option is used in pcretest.
712    
713    25. The CheckMan script was not being included in the distribution. Also, added
714        an explicit "perl" to run Perl scripts from the PrepareRelease script
715        because this is reportedly needed in Windows.
716    
717    26. If study data was being save in a file and studying had not found a set of
718        "starts with" bytes for the pattern, the data written to the file (though
719        never used) was taken from uninitialized memory and so caused valgrind to
720        complain.
721    
722    27. Updated RunTest.bat as provided by Sheri Pierce.
723    
724    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
725    
726    29. Computation of memory usage for the table of capturing group names was
727        giving an unnecessarily large value.
728    
729    
730    Version 8.20 21-Oct-2011
731    ------------------------
732    
733    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
734        a POSIX class. After further experiments with Perl, which convinced me that
735        Perl has bugs and confusions, a closing square bracket is no longer allowed
736        in a POSIX name. This bug also affected patterns with classes that started
737        with full stops.
738    
739    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
740        captured substring, but while checking the failing first alternative,
741        substring 1 is temporarily captured. If the output vector supplied to
742        pcre_exec() was not big enough for this capture, the yield of the function
743        was still zero ("insufficient space for captured substrings"). This cannot
744        be totally fixed without adding another stack variable, which seems a lot
745        of expense for a edge case. However, I have improved the situation in cases
746        such as /(a)(b)x|abc/ matched against "abc", where the return code
747        indicates that fewer than the maximum number of slots in the ovector have
748        been set.
749    
750    3.  Related to (2) above: when there are more back references in a pattern than
751        slots in the output vector, pcre_exec() uses temporary memory during
752        matching, and copies in the captures as far as possible afterwards. It was
753        using the entire output vector, but this conflicts with the specification
754        that only 2/3 is used for passing back captured substrings. Now it uses
755        only the first 2/3, for compatibility. This is, of course, another edge
756        case.
757    
758    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
759        main code base, and can be used by building with --enable-jit. When this is
760        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
761        runtime --no-jit option is given.
762    
763    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
764        ovector, the return from the function was zero, implying that there were
765        other matches that did not fit. The correct "exactly full" value is now
766        returned.
767    
768    6.  If a subpattern that was called recursively or as a subroutine contained
769        (*PRUNE) or any other control that caused it to give a non-standard return,
770        invalid errors such as "Error -26 (nested recursion at the same subject
771        position)" or even infinite loops could occur.
772    
773    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
774        computing the minimum length on reaching *ACCEPT, and so ended up with the
775        wrong value of 1 rather than 0. Further investigation indicates that
776        computing a minimum subject length in the presence of *ACCEPT is difficult
777        (think back references, subroutine calls), and so I have changed the code
778        so that no minimum is registered for a pattern that contains *ACCEPT.
779    
780    8.  If (*THEN) was present in the first (true) branch of a conditional group,
781        it was not handled as intended. [But see 16 below.]
782    
783    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
784        Sheri Pierce.
785    
786    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
787        the first byte in a match must be "a".
788    
789    11. Change 17 for 8.13 increased the recursion depth for patterns like
790        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
791        pattern contains any instances of (*THEN). If it does not, the old
792        optimizations are restored. It would be nice to do this on a per-group
793        basis, but at the moment that is not feasible.
794    
795    12. In some environments, the output of pcretest -C is CRLF terminated. This
796        broke RunTest's code that checks for the link size. A single white space
797        character after the value is now allowed for.
798    
799    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
800        For "fr", it uses the Windows-specific input and output files.
801    
802    14. If (*THEN) appeared in a group that was called recursively or as a
803        subroutine, it did not work as intended. [But see next item.]
804    
805    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
806        pattern fragments (but not containing any | characters). If A and B are
807        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
808        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
809        D. In other words, Perl considers parentheses that do not contain any |
810        characters to be part of a surrounding alternative, whereas PCRE was
811        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
812        differently. PCRE now behaves in the same way as Perl, except in the case
813        of subroutine/recursion calls such as (?1) which have in any case always
814        been different (but PCRE had them first :-).
815    
816    16. Related to 15 above: Perl does not treat the | in a conditional group as
817        creating alternatives. Such a group is treated in the same way as an
818        ordinary group without any | characters when processing (*THEN). PCRE has
819        been changed to match Perl's behaviour.
820    
821    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
822        RunGrepTest script failed.
823    
824    18. Change 22 for version 13 caused atomic groups to use more stack. This is
825        inevitable for groups that contain captures, but it can lead to a lot of
826        stack use in large patterns. The old behaviour has been restored for atomic
827        groups that do not contain any capturing parentheses.
828    
829    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
830        suppress the check for a minimum subject length at run time. (If it was
831        given to pcre_exec() or pcre_dfa_exec() it did work.)
832    
833    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
834        fail to work when decoding hex characters in data strings in EBCDIC
835        environments.
836    
837    21. It appears that in at least one Mac OS environment, the isxdigit() function
838        is implemented as a macro that evaluates to its argument more than once,
839        contravening the C 90 Standard (I haven't checked a later standard). There
840        was an instance in pcretest which caused it to go wrong when processing
841        \x{...} escapes in subject strings. The has been rewritten to avoid using
842        things like p++ in the argument of isxdigit().
843    
844    
845    Version 8.13 16-Aug-2011
846  ------------------------  ------------------------
847    
848  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 20  Version 8.13 30-Apr-2011 Line 861  Version 8.13 30-Apr-2011
861      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
862      2-byte code at the end of the subject (it thought there wasn't enough data      2-byte code at the end of the subject (it thought there wasn't enough data
863      left).      left).
864    
865  5.  Comprehensive information about what went wrong is now returned by  5.  Comprehensive information about what went wrong is now returned by
866      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
867      as the output vector has at least 2 elements. The offset of the start of      as the output vector has at least 2 elements. The offset of the start of
868      the failing character and a reason code are placed in the vector.      the failing character and a reason code are placed in the vector.
869    
870  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
871      now returned is for the first byte of the failing character, instead of the      now returned is for the first byte of the failing character, instead of the
872      last byte inspected. This is an incompatible change, but I hope it is small      last byte inspected. This is an incompatible change, but I hope it is small
873      enough not to be a problem. It makes the returned offset consistent with      enough not to be a problem. It makes the returned offset consistent with
874      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
875    
876  7.  pcretest now gives a text phrase as well as the error number when  7.  pcretest now gives a text phrase as well as the error number when
877      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
878      failure, the offset and reason code are output.      failure, the offset and reason code are output.
879    
880  8.  When \R was used with a maximizing quantifier it failed to skip backwards  8.  When \R was used with a maximizing quantifier it failed to skip backwards
881      over a \r\n pair if the subsequent match failed. Instead, it just skipped      over a \r\n pair if the subsequent match failed. Instead, it just skipped
882      back over a single character (\n). This seems wrong (because it treated the      back over a single character (\n). This seems wrong (because it treated the
883      two characters as a single entity when going forwards), conflicts with the      two characters as a single entity when going forwards), conflicts with the
884      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
885      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
886      has been changed.      has been changed.
887    
888  9.  Some internal refactoring has changed the processing so that the handling  9.  Some internal refactoring has changed the processing so that the handling
889      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
890      time (the PCRE_DOTALL option was changed this way some time ago: version      time (the PCRE_DOTALL option was changed this way some time ago: version
891      7.7 change 16). This has made it possible to abolish the OP_OPT op code,      7.7 change 16). This has made it possible to abolish the OP_OPT op code,
892      which was always a bit of a fudge. It also means that there is one less      which was always a bit of a fudge. It also means that there is one less
893      argument for the match() function, which reduces its stack requirements      argument for the match() function, which reduces its stack requirements
894      slightly. This change also fixes an incompatibility with Perl: the pattern      slightly. This change also fixes an incompatibility with Perl: the pattern
895      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
896    
897  10. More internal refactoring has drastically reduced the number of recursive  10. More internal refactoring has drastically reduced the number of recursive
898      calls to match() for possessively repeated groups such as (abc)++ when      calls to match() for possessively repeated groups such as (abc)++ when
899      using pcre_exec().      using pcre_exec().
900    
901  11. While implementing 10, a number of bugs in the handling of groups were  11. While implementing 10, a number of bugs in the handling of groups were
902      discovered and fixed:      discovered and fixed:
903    
904      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
905      (a|)*(?1) gave a compile-time internal error.      (a|)*(?1) gave a compile-time internal error.
906      ((a|)+)+  did not notice that the outer group could match an empty string.      ((a|)+)+  did not notice that the outer group could match an empty string.
907      (^a|^)+   was not marked as anchored.      (^a|^)+   was not marked as anchored.
908      (.*a|.*)+ was not marked as matching at start or after a newline.      (.*a|.*)+ was not marked as matching at start or after a newline.
909    
910  12. Yet more internal refactoring has removed another argument from the match()  12. Yet more internal refactoring has removed another argument from the match()
911      function. Special calls to this function are now indicated by setting a      function. Special calls to this function are now indicated by setting a
912      value in a variable in the "match data" data block.      value in a variable in the "match data" data block.
913    
914  13. Be more explicit in pcre_study() instead of relying on "default" for  13. Be more explicit in pcre_study() instead of relying on "default" for
915      opcodes that mean there is no starting character; this means that when new      opcodes that mean there is no starting character; this means that when new
916      ones are added and accidentally left out of pcre_study(), testing should      ones are added and accidentally left out of pcre_study(), testing should
917      pick them up.      pick them up.
918    
919  14. The -s option of pcretest has been documented for ages as being an old  14. The -s option of pcretest has been documented for ages as being an old
920      synonym of -m (show memory usage). I have changed it to mean "force study      synonym of -m (show memory usage). I have changed it to mean "force study
921      for every regex", that is, assume /S for every regex. This is similar to -i      for every regex", that is, assume /S for every regex. This is similar to -i
922      and -d etc. It's slightly incompatible, but I'm hoping nobody is still      and -d etc. It's slightly incompatible, but I'm hoping nobody is still
923      using it. It makes it easier to run collection of tests with study enabled,      using it. It makes it easier to run collections of tests with and without
924      and thereby test pcre_study() more easily.      study enabled, and thereby test pcre_study() more easily. All the standard
925        tests are now run with and without -s (but some patterns can be marked as
926        "never study" - see 20 below).
927    
928  15. When (*ACCEPT) was used in a subpattern that was called recursively, the  15. When (*ACCEPT) was used in a subpattern that was called recursively, the
929      restoration of the capturing data to the outer values was not happening      restoration of the capturing data to the outer values was not happening
930      correctly.      correctly.
931    
932  16. If a recursively called subpattern ended with (*ACCEPT) and matched an  16. If a recursively called subpattern ended with (*ACCEPT) and matched an
933      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
934      pattern had matched an empty string, and so incorrectly returned a no      pattern had matched an empty string, and so incorrectly returned a no
935      match.      match.
936    
937    17. There was optimizing code for the last branch of non-capturing parentheses,
938        and also for the obeyed branch of a conditional subexpression, which used
939        tail recursion to cut down on stack usage. Unfortunately, now that there is
940        the possibility of (*THEN) occurring in these branches, tail recursion is
941        no longer possible because the return has to be checked for (*THEN). These
942        two optimizations have therefore been removed. [But see 8.20/11 above.]
943    
944    18. If a pattern containing \R was studied, it was assumed that \R always
945        matched two bytes, thus causing the minimum subject length to be
946        incorrectly computed because \R can also match just one byte.
947    
948    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
949        was incorrectly computed.
950    
951    20. If /S is present twice on a test pattern in pcretest input, it now
952        *disables* studying, thereby overriding the use of -s on the command line
953        (see 14 above). This is necessary for one or two tests to keep the output
954        identical in both cases.
955    
956    21. When (*ACCEPT) was used in an assertion that matched an empty string and
957        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
958    
959    22. When an atomic group that contained a capturing parenthesis was
960        successfully matched, but the branch in which it appeared failed, the
961        capturing was not being forgotten if a higher numbered group was later
962        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
963        group 1 to "a", when in fact it should be unset. This applied to multi-
964        branched capturing and non-capturing groups, repeated or not, and also to
965        positive assertions (capturing in negative assertions does not happen
966        in PCRE) and also to nested atomic groups.
967    
968    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
969        subject after a captured substring, to make it easier to tell which of a
970        number of identical substrings has been captured.
971    
972    24. The way atomic groups are processed by pcre_exec() has been changed so that
973        if they are repeated, backtracking one repetition now resets captured
974        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
975        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
976        "aaa". Previously, it would have been "a". As part of this code
977        refactoring, the way recursive calls are handled has also been changed.
978    
979    25. If an assertion condition captured any substrings, they were not passed
980        back unless some other capturing happened later. For example, if
981        (?(?=(a))a) was matched against "a", no capturing was returned.
982    
983    26. When studying a pattern that contained subroutine calls or assertions,
984        the code for finding the minimum length of a possible match was handling
985        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
986        group 1 called group 2 while simultaneously a separate group 2 called group
987        1). A stack overflow occurred in this case. I have fixed this by limiting
988        the recursion depth to 10.
989    
990    27. Updated RunTest.bat in the distribution to the version supplied by Tom
991        Fortmann. This supports explicit test numbers on the command line, and has
992        argument validation and error reporting.
993    
994    28. An instance of \X with an unlimited repeat could fail if at any point the
995        first character it looked at was a mark character.
996    
997    29. Some minor code refactoring concerning Unicode properties and scripts
998        should reduce the stack requirement of match() slightly.
999    
1000    30. Added the '=' option to pcretest to check the setting of unused capturing
1001        slots at the end of the pattern, which are documented as being -1, but are
1002        not included in the return count.
1003    
1004    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1005        compiled something random. Now it gives a compile-time error (as does
1006        Perl).
1007    
1008    32. A *MARK encountered during the processing of a positive assertion is now
1009        recorded and passed back (compatible with Perl).
1010    
1011    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1012        had alternative anchored branches, the search for a second match in a line
1013        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1014        matched the line "0102" twice. The same bug affected patterns that started
1015        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1016        twice.
1017    
1018    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1019        does, and because of capturing effects, quantifying parenthesized
1020        assertions may at times be useful. Quantifiers are now allowed for
1021        parenthesized assertions.
1022    
1023    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1024    
1025    36. \g was being checked for fancy things in a character class, when it should
1026        just be a literal "g".
1027    
1028    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1029        appearance of a nested POSIX class supersedes an apparent external class.
1030        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1031        unescaped square brackets may also appear as part of class names. For
1032        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1033        more like Perl. (But see 8.20/1 above.)
1034    
1035    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1036        was because it thought it was \N{name}, which is not supported).
1037    
1038    39. Add minix to OS list not supporting the -S option in pcretest.
1039    
1040    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1041        cannot analyze patterns in sufficient detail to catch mutual recursions
1042        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1043        subgroup is called recursively as a subpattern for a second time at the
1044        same position in the subject string. In previous releases this might have
1045        been caught by the recursion limit, or it might have run out of stack.
1046    
1047    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1048        happen only once. PCRE was, however incorrectly giving a compile time error
1049        "recursive call could loop indefinitely" because it cannot analyze the
1050        pattern in sufficient detail. The compile time test no longer happens when
1051        PCRE is compiling a conditional subpattern, but actual runaway loops are
1052        now caught at runtime (see 40 above).
1053    
1054    42. It seems that Perl allows any characters other than a closing parenthesis
1055        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1056        has been changed to be the same.
1057    
1058    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1059        as not to get warnings when autogen.sh is called. Also changed
1060        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1061    
1062    44. To help people who use pcregrep to scan files containing exceedingly long
1063        lines, the following changes have been made:
1064    
1065        (a) The default value of the buffer size parameter has been increased from
1066            8K to 20K. (The actual buffer used is three times this size.)
1067    
1068        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1069            PCRE is built.
1070    
1071        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1072            to be set at run time.
1073    
1074        (d) Numerical values in pcregrep options can be followed by K or M, for
1075            example --buffer-size=50K.
1076    
1077        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1078            given and the return code is set to 2.
1079    
1080    45. Add a pointer to the latest mark to the callout data block.
1081    
1082    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1083        partial match of an empty string instead of no match. This was specific to
1084        the use of ".".
1085    
1086    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1087        complete match instead of a partial match. This bug was dependent on both
1088        the PCRE_UTF8 and PCRE_DOTALL options being set.
1089    
1090    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1091        starting byte set, because \b was not being ignored.
1092    
1093    
1094  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
1095  ------------------------  ------------------------
# Line 742  Version 7.9 11-Apr-09 Line 1741  Version 7.9 11-Apr-09
1741  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
1742      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
1743      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1744      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1745        8.33.]
1746    
1747  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
1748      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 985  Version 7.7 07-May-08 Line 1985  Version 7.7 07-May-08
1985      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
1986      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
1987      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
1988      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
1989      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
1990      was subsequently set up correctly.)      was subsequently set up correctly.)
1991    

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