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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    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.
77    
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.
82    
83    
84    Version 8.33 28-May-2013
85    ------------------------
86    
87    1.  Added 'U' to some constants that are compared to unsigned integers, to
88        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
89        variables that are added to signed variables, to ensure the result is
90        signed and can be negated.
91    
92    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
93        CMake config files.
94    
95    3.  Revise the creation of config.h.generic so that all boolean macros are
96        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
97        overriding via -D on the command line possible.
98    
99    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
100        to unsigned int is reported to make a quite noticeable speed difference in
101        a specific Windows environment. Testing on Linux did also appear to show
102        some benefit (and it is clearly not harmful). Also fixed the definition of
103        Xop which should be unsigned.
104    
105    5.  Related to (4), changing the definition of the intermediate variable cc
106        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
107        improvements.
108    
109    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
110        unnecessary spaces.
111    
112    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
113        and later.
114    
115    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
116    
117    9.  Optimizing fast_forward_start_bits in JIT.
118    
119    10. Adding support for callouts in JIT, and fixing some issues revealed
120        during this work. Namely:
121    
122        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
123    
124        (b) Minimum length was not checked before the matching is started.
125    
126    11. The value of capture_last that is passed to callouts was incorrect in some
127        cases when there was a capture on one path that was subsequently abandoned
128        after a backtrack. Also, the capture_last value is now reset after a
129        recursion, since all captures are also reset in this case.
130    
131    12. The interpreter no longer returns the "too many substrings" error in the
132        case when an overflowing capture is in a branch that is subsequently
133        abandoned after a backtrack.
134    
135    13. In the pathological case when an offset vector of size 2 is used, pcretest
136        now prints out the matched string after a yield of 0 or 1.
137    
138    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
139        Only supported by the JIT compiler at the moment.
140    
141    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
142    
143    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
144        offset of the starting point of the matching process, provided the offsets
145        vector is large enough.
146    
147    17. The \A escape now records a lookbehind value of 1, though its execution
148        does not actually inspect the previous character. This is to ensure that,
149        in partial multi-segment matching, at least one character from the old
150        segment is retained when a new segment is processed. Otherwise, if there
151        are no lookbehinds in the pattern, \A might match incorrectly at the start
152        of a new segment.
153    
154    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
155    
156    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
157        gives some modest performance improvement in 8-bit mode.
158    
159    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
160        be expressed in certain programming languages using Universal Character
161        Names.
162    
163    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
164        which points out that "non characters" are not "characters that may not
165        appear in Unicode strings" but rather "characters that are reserved for
166        internal use and have only local meaning".
167    
168    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
169        there was a conditional group that depended on an assertion, if the
170        assertion was false, the callout that immediately followed the alternation
171        in the condition was skipped when pcre_exec() was used for matching.
172    
173    23. Allow an explicit callout to be inserted before an assertion that is the
174        condition for a conditional group, for compatibility with automatic
175        callouts, which always insert a callout at this point.
176    
177    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
178        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
179    
180    25. (*PRUNE) is now supported by the JIT compiler.
181    
182    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
183    
184    27. Fix the case where there are two or more SKIPs with arguments that may be
185        ignored.
186    
187    28. (*SKIP) is now supported by the JIT compiler.
188    
189    29. (*THEN) is now supported by the JIT compiler.
190    
191    30. Update RunTest with additional test selector options.
192    
193    31. The way PCRE handles backtracking verbs has been changed in two ways.
194    
195        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
196        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
197        backtracking. In some cases this makes it more Perl-compatible, but Perl's
198        rather obscure rules do not always do the same thing.
199    
200        (2) Previously, backtracking verbs were confined within assertions. This is
201        no longer the case for positive assertions, except for (*ACCEPT). Again,
202        this sometimes improves Perl compatibility, and sometimes does not.
203    
204    32. A number of tests that were in test 2 because Perl did things differently
205        have been moved to test 1, because either Perl or PCRE has changed, and
206        these tests are now compatible.
207    
208    32. Backtracking control verbs are now handled in the same way in JIT and
209        interpreter.
210    
211    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
212        contained a forward subroutine reference caused a compile error.
213    
214    34. Auto-detect and optimize limited repetitions in JIT.
215    
216    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
217        blocking (*UTF) etc.
218    
219    36. In the interpreter, maximizing pattern repetitions for characters and
220        character types now use tail recursion, which reduces stack usage.
221    
222    37. The value of the max lookbehind was not correctly preserved if a compiled
223        and saved regex was reloaded on a host of different endianness.
224    
225    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
226        of the compiled pattern block, expand the flags field from 16 to 32 bits
227        because it was almost full.
228    
229    39. Try madvise first before posix_madvise.
230    
231    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
232        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
233        original change locked out all matches of empty strings. This has been
234        changed so that one match of an empty string per line is recognized.
235        Subsequent searches on the same line (for colouring or for --only-matching,
236        for example) do not recognize empty strings.
237    
238    41. Applied a user patch to fix a number of spelling mistakes in comments.
239    
240    42. Data lines longer than 65536 caused pcretest to crash.
241    
242    43. Clarified the data type for length and startoffset arguments for pcre_exec
243        and pcre_dfa_exec in the function-specific man pages, where they were
244        explicitly stated to be in bytes, never having been updated. I also added
245        some clarification to the pcreapi man page.
246    
247    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
248        a segmentation fault.
249    
250    
251    Version 8.32 30-November-2012
252    -----------------------------
253    
254    1.  Improved JIT compiler optimizations for first character search and single
255        character iterators.
256    
257    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
258        Patch by Daniel Richard G.
259    
260    3.  Single character iterator optimizations in the JIT compiler.
261    
262    4.  Improved JIT compiler optimizations for character ranges.
263    
264    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
265        Reported by Giuseppe D'Angelo.
266    
267    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
268        of a line, was being set incorrectly in cases where .* appeared inside
269        atomic brackets at the start of a pattern, or where there was a subsequent
270        *PRUNE or *SKIP.
271    
272    7.  Improved instruction cache flush for POWER/PowerPC.
273        Patch by Daniel Richard G.
274    
275    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
276        grep:
277    
278        (a) There is now no limit to the number of patterns to be matched.
279    
280        (b) An error is given if a pattern is too long.
281    
282        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
283            are now supported.
284    
285        (d) --exclude-from and --include-from (multiple use) have been added.
286    
287        (e) Exclusions and inclusions now apply to all files and directories, not
288            just to those obtained from scanning a directory recursively.
289    
290        (f) Multiple uses of -f and --file-list are now supported.
291    
292        (g) In a Windows environment, the default for -d has been changed from
293            "read" (the GNU grep default) to "skip", because otherwise the presence
294            of a directory in the file list provokes an error.
295    
296        (h) The documentation has been revised and clarified in places.
297    
298    9.  Improve the matching speed of capturing brackets.
299    
300    10. Changed the meaning of \X so that it now matches a Unicode extended
301        grapheme cluster.
302    
303    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
304        out POSIX threads when JIT support is configured.
305    
306    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
307    
308    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
309        structure could go wrong in environments where size_t is not the same size
310        as int.
311    
312    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
313        set.
314    
315    15. The EBCDIC support had decayed; later updates to the code had included
316        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
317        general tidy up of EBCDIC-related issues, and the documentation was also
318        not quite right. There is now a test that can be run on ASCII systems to
319        check some of the EBCDIC-related things (but is it not a full test).
320    
321    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
322        in a small tidy to the code.
323    
324    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
325    
326    18. If the --only-matching (-o) option in pcregrep is specified multiple
327        times, each one causes appropriate output. For example, -o1 -o2 outputs the
328        substrings matched by the 1st and 2nd capturing parentheses. A separating
329        string can be specified by --om-separator (default empty).
330    
331    19. Improving the first n character searches.
332    
333    20. Turn case lists for horizontal and vertical white space into macros so that
334        they are defined only once.
335    
336    21. This set of changes together give more compatible Unicode case-folding
337        behaviour for characters that have more than one other case when UCP
338        support is available.
339    
340        (a) The Unicode property table now has offsets into a new table of sets of
341            three or more characters that are case-equivalent. The MultiStage2.py
342            script that generates these tables (the pcre_ucd.c file) now scans
343            CaseFolding.txt instead of UnicodeData.txt for character case
344            information.
345    
346        (b) The code for adding characters or ranges of characters to a character
347            class has been abstracted into a generalized function that also handles
348            case-independence. In UTF-mode with UCP support, this uses the new data
349            to handle characters with more than one other case.
350    
351        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
352            whose other case is greater than 256 are now correctly matched
353            caselessly. Previously, the high codepoint matched the low one, but not
354            vice versa.
355    
356        (d) The processing of \h, \H, \v, and \ in character classes now makes use
357            of the new class addition function, using character lists defined as
358            macros alongside the case definitions of 20 above.
359    
360        (e) Caseless back references now work with characters that have more than
361            one other case.
362    
363        (f) General caseless matching of characters with more than one other case
364            is supported.
365    
366    22. Unicode character properties were updated from Unicode 6.2.0
367    
368    23. Improved CMake support under Windows. Patch by Daniel Richard G.
369    
370    24. Add support for 32-bit character strings, and UTF-32
371    
372    25. Major JIT compiler update (code refactoring and bugfixing).
373        Experimental Sparc 32 support is added.
374    
375    26. Applied a modified version of Daniel Richard G's patch to create
376        pcre.h.generic and config.h.generic by "make" instead of in the
377        PrepareRelease script.
378    
379    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
380        pcre_compile.c when checking for a zero character.
381    
382    28. Introducing a native interface for JIT. Through this interface, the compiled
383        machine code can be directly executed. The purpose of this interface is to
384        provide fast pattern matching, so several sanity checks are not performed.
385        However, feature tests are still performed. The new interface provides
386        1.4x speedup compared to the old one.
387    
388    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
389        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
390        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
391    
392    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
393        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
394        the "old" RFC 2279). Instead, it ended up passing a negative length to
395        pcre_exec().
396    
397    31. Add support for GCC's visibility feature to hide internal functions.
398    
399    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
400        "unknown -C option" after outputting 0 or 1.
401    
402    33. There is now support for generating a code coverage report for the test
403        suite in environments where gcc is the compiler and lcov is installed. This
404        is mainly for the benefit of the developers.
405    
406    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
407        unaddressable using valgrind annotations, allowing valgrind to detect
408        invalid memory accesses. This is mainly for the benefit of the developers.
409    
410    25. (*UTF) can now be used to start a pattern in any of the three libraries.
411    
412    26. Give configure error if --enable-cpp but no C++ compiler found.
413    
414    
415    Version 8.31 06-July-2012
416    -------------------------
417    
418    1.  Fixing a wrong JIT test case and some compiler warnings.
419    
420    2.  Removed a bashism from the RunTest script.
421    
422    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
423        to unsigned type, result still unsigned" that was given by an MS compiler
424        on encountering the code "-sizeof(xxx)".
425    
426    4.  Partial matching support is added to the JIT compiler.
427    
428    5.  Fixed several bugs concerned with partial matching of items that consist
429        of more than one character:
430    
431        (a) /^(..)\1/ did not partially match "aba" because checking references was
432            done on an "all or nothing" basis. This also applied to repeated
433            references.
434    
435        (b) \R did not give a hard partial match if \r was found at the end of the
436            subject.
437    
438        (c) \X did not give a hard partial match after matching one or more
439            characters at the end of the subject.
440    
441        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
442            a partial match for the string "\r".
443    
444        (e) When newline was set to CRLF, the metacharacter "." did not recognize
445            a partial match for a CR character at the end of the subject string.
446    
447    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
448        running pcretest, the text "(JIT)" added to the output whenever JIT is
449        actually used to run the match.
450    
451    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
452        or /S+[+] with a digit between 1 and 7.
453    
454    8.  OP_NOT now supports any UTF character not just single-byte ones.
455    
456    9.  (*MARK) control verb is now supported by the JIT compiler.
457    
458    10. The command "./RunTest list" lists the available tests without actually
459        running any of them. (Because I keep forgetting what they all are.)
460    
461    11. Add PCRE_INFO_MAXLOOKBEHIND.
462    
463    12. Applied a (slightly modified) user-supplied patch that improves performance
464        when the heap is used for recursion (compiled with --disable-stack-for-
465        recursion). Instead of malloc and free for each heap frame each time a
466        logical recursion happens, frames are retained on a chain and re-used where
467        possible. This sometimes gives as much as 30% improvement.
468    
469    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
470        call.
471    
472    14. As documented, (*COMMIT) is now confined to within a positive assertion.
473    
474    15. It is now possible to link pcretest with libedit as an alternative to
475        libreadline.
476    
477    16. (*COMMIT) control verb is now supported by the JIT compiler.
478    
479    17. The Unicode data tables have been updated to Unicode 6.1.0.
480    
481    18. Added --file-list option to pcregrep.
482    
483    19. Added binary file support to pcregrep, including the -a, --binary-files,
484        -I, and --text options.
485    
486    20. The madvise function is renamed for posix_madvise for QNX compatibility
487        reasons. Fixed by Giuseppe D'Angelo.
488    
489    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
490    
491    22. Changed the option for creating symbolic links for 16-bit man pages from
492        -s to -sf so that re-installing does not cause issues.
493    
494    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
495    
496    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
497        matches in certain environments (the workspace was not being correctly
498        retained). Also added to pcre_dfa_exec() a simple plausibility check on
499        some of the workspace data at the beginning of a restart.
500    
501    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
502        was not doing so when it should - probably a typo introduced by SVN 528
503        (change 8.10/14).
504    
505    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
506        \w+ when the character tables indicated that \x{c4} was a word character.
507        There were several related cases, all because the tests for doing a table
508        lookup were testing for characters less than 127 instead of 255.
509    
510    27. If a pattern contains capturing parentheses that are not used in a match,
511        their slots in the ovector are set to -1. For those that are higher than
512        any matched groups, this happens at the end of processing. In the case when
513        there were back references that the ovector was too small to contain
514        (causing temporary malloc'd memory to be used during matching), and the
515        highest capturing number was not used, memory off the end of the ovector
516        was incorrectly being set to -1. (It was using the size of the temporary
517        memory instead of the true size.)
518    
519    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
520        ovector size, it uses memory at the end of the block that it has got.
521    
522    29. Check for an overlong MARK name and give an error at compile time. The
523        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
524    
525    30. JIT compiler update.
526    
527    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
528        Rill for the patch.
529    
530    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
531    
532    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
533    
534    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
535        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
536        was enabled.
537    
538    35. Improve JIT code generation for greedy plus quantifier.
539    
540    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
541        1 to "aa" instead of to an empty string. The bug affected repeated groups
542        that could potentially match an empty string.
543    
544    37. Optimizing single character iterators in JIT.
545    
546    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
547        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
548        codepoints that are too big for the mode are faulted, and in a UTF mode,
549        disallowed codepoints are also faulted.
550    
551    39. If PCRE was compiled with UTF support, in three places in the DFA
552        matcher there was code that should only have been obeyed in UTF mode, but
553        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
554        processing when bytes with values greater than 127 were present. In 16-bit
555        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
556        both cases the values are those that cannot be the first data item in a UTF
557        character. The three items that might have provoked this were recursions,
558        possessively repeated groups, and atomic groups.
559    
560    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
561        and pcregrep, because some OS require shared objects to be explicitly
562        passed to ld, causing the link step to fail if they are not.
563    
564    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
565        mode, patterns that started with \h* or \R* might be incorrectly matched.
566    
567    
568    Version 8.30 04-February-2012
569    -----------------------------
570    
571    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
572        name is defined in ctype.h.
573    
574    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
575        only in quite long subpatterns.
576    
577    3.  Removed the function pcre_info(), which has been obsolete and deprecated
578        since it was replaced by pcre_fullinfo() in February 2000.
579    
580    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
581        match a (*MARK), and the match failed at the start of the subject, a
582        reference to memory before the start of the subject could occur. This bug
583        was introduced by fix 17 of release 8.21.
584    
585    5.  A reference to an unset group with zero minimum repetition was giving
586        totally wrong answers (in non-JavaScript-compatibility mode). For example,
587        /(another)?(\1?)test/ matched against "hello world test". This bug was
588        introduced in release 8.13.
589    
590    6.  Add support for 16-bit character strings (a large amount of work involving
591        many changes and refactorings).
592    
593    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
594        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
595        from a file.
596    
597    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
598        rounding is not applied in this particular case).
599    
600    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
601        if they appear, or are escaped, in patterns.
602    
603    10. Get rid of a number of -Wunused-but-set-variable warnings.
604    
605    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
606        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
607        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
608        also returns the mark "x". This bug applied to capturing parentheses,
609        non-capturing parentheses, and atomic parentheses. It also applied to some
610        assertions.
611    
612    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
613        information out of configure.ac instead of relying on pcre.h.generic, which
614        is not stored in the repository.
615    
616    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
617        -lreadline.
618    
619    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
620    
621    15. Applied Graycode's patch to put the top-level frame on the stack rather
622        than the heap when not using the stack for recursion. This gives a
623        performance improvement in many cases when recursion is not deep.
624    
625    16. Experimental code added to "pcretest -C" to output the stack frame size.
626    
627    
628    Version 8.21 12-Dec-2011
629    ------------------------
630    
631    1.  Updating the JIT compiler.
632    
633    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
634        are added as well.
635    
636    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
637        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
638        calling _pcre_jit_exec. Some extra comments are added.
639    
640    4.  (*MARK) settings inside atomic groups that do not contain any capturing
641        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
642        was introduced by change 18 for 8.20.
643    
644    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
645        ECMA-262 standard.
646    
647    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
648        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
649        This bug was probably introduced by change 9 of 8.13.
650    
651    7.  While fixing 6 above, I noticed that a number of other items were being
652        incorrectly rejected as "not fixed length". This arose partly because newer
653        opcodes had not been added to the fixed-length checking code. I have (a)
654        corrected the bug and added tests for these items, and (b) arranged for an
655        error to occur if an unknown opcode is encountered while checking for fixed
656        length instead of just assuming "not fixed length". The items that were
657        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
658        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
659        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
660    
661    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
662        being incorrectly compiled and would have given unpredicatble results.
663    
664    9.  A possessively repeated subpattern with minimum repeat count greater than
665        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
666        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
667        the first (A) could occur when it should not.
668    
669    10. Add a cast and remove a redundant test from the code.
670    
671    11. JIT should use pcre_malloc/pcre_free for allocation.
672    
673    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
674        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
675        is anything other than /usr, -L is still shown).
676    
677    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
678    
679    14. Perl does not support \N without a following name in a [] class; PCRE now
680        also gives an error.
681    
682    15. If a forward reference was repeated with an upper limit of around 2000,
683        it caused the error "internal error: overran compiling workspace". The
684        maximum number of forward references (including repeats) was limited by the
685        internal workspace, and dependent on the LINK_SIZE. The code has been
686        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
687        the default depends on LINK_SIZE. There is a new upper limit (for safety)
688        of around 200,000 forward references. While doing this, I also speeded up
689        the filling in of repeated forward references.
690    
691    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
692        incorrectly expecting the subject to contain another "a" after the start.
693    
694    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
695        in the match, the SKIP should be ignored. This was not happening; instead
696        the SKIP was being treated as NOMATCH. For patterns such as
697        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
698        tested.
699    
700    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
701        now much more compatible with Perl, in particular in cases where the result
702        is a non-match for a non-anchored pattern. For example, if
703        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
704        "m", where previously it did not return a name. A side effect of this
705        change is that for partial matches, the last encountered mark name is
706        returned, as for non matches. A number of tests that were previously not
707        Perl-compatible have been moved into the Perl-compatible test files. The
708        refactoring has had the pleasing side effect of removing one argument from
709        the match() function, thus reducing its stack requirements.
710    
711    19. If the /S+ option was used in pcretest to study a pattern using JIT,
712        subsequent uses of /S (without +) incorrectly behaved like /S+.
713    
714    21. Retrieve executable code size support for the JIT compiler and fixing
715        some warnings.
716    
717    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
718        not work when the shorter character appeared right at the end of the
719        subject string.
720    
721    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
722        systems.
723    
724    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
725        output it when the /M option is used in pcretest.
726    
727    25. The CheckMan script was not being included in the distribution. Also, added
728        an explicit "perl" to run Perl scripts from the PrepareRelease script
729        because this is reportedly needed in Windows.
730    
731    26. If study data was being save in a file and studying had not found a set of
732        "starts with" bytes for the pattern, the data written to the file (though
733        never used) was taken from uninitialized memory and so caused valgrind to
734        complain.
735    
736    27. Updated RunTest.bat as provided by Sheri Pierce.
737    
738    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
739    
740    29. Computation of memory usage for the table of capturing group names was
741        giving an unnecessarily large value.
742    
743    
744    Version 8.20 21-Oct-2011
745    ------------------------
746    
747    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
748        a POSIX class. After further experiments with Perl, which convinced me that
749        Perl has bugs and confusions, a closing square bracket is no longer allowed
750        in a POSIX name. This bug also affected patterns with classes that started
751        with full stops.
752    
753    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
754        captured substring, but while checking the failing first alternative,
755        substring 1 is temporarily captured. If the output vector supplied to
756        pcre_exec() was not big enough for this capture, the yield of the function
757        was still zero ("insufficient space for captured substrings"). This cannot
758        be totally fixed without adding another stack variable, which seems a lot
759        of expense for a edge case. However, I have improved the situation in cases
760        such as /(a)(b)x|abc/ matched against "abc", where the return code
761        indicates that fewer than the maximum number of slots in the ovector have
762        been set.
763    
764    3.  Related to (2) above: when there are more back references in a pattern than
765        slots in the output vector, pcre_exec() uses temporary memory during
766        matching, and copies in the captures as far as possible afterwards. It was
767        using the entire output vector, but this conflicts with the specification
768        that only 2/3 is used for passing back captured substrings. Now it uses
769        only the first 2/3, for compatibility. This is, of course, another edge
770        case.
771    
772    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
773        main code base, and can be used by building with --enable-jit. When this is
774        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
775        runtime --no-jit option is given.
776    
777    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
778        ovector, the return from the function was zero, implying that there were
779        other matches that did not fit. The correct "exactly full" value is now
780        returned.
781    
782    6.  If a subpattern that was called recursively or as a subroutine contained
783        (*PRUNE) or any other control that caused it to give a non-standard return,
784        invalid errors such as "Error -26 (nested recursion at the same subject
785        position)" or even infinite loops could occur.
786    
787    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
788        computing the minimum length on reaching *ACCEPT, and so ended up with the
789        wrong value of 1 rather than 0. Further investigation indicates that
790        computing a minimum subject length in the presence of *ACCEPT is difficult
791        (think back references, subroutine calls), and so I have changed the code
792        so that no minimum is registered for a pattern that contains *ACCEPT.
793    
794    8.  If (*THEN) was present in the first (true) branch of a conditional group,
795        it was not handled as intended. [But see 16 below.]
796    
797    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
798        Sheri Pierce.
799    
800    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
801        the first byte in a match must be "a".
802    
803    11. Change 17 for 8.13 increased the recursion depth for patterns like
804        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
805        pattern contains any instances of (*THEN). If it does not, the old
806        optimizations are restored. It would be nice to do this on a per-group
807        basis, but at the moment that is not feasible.
808    
809    12. In some environments, the output of pcretest -C is CRLF terminated. This
810        broke RunTest's code that checks for the link size. A single white space
811        character after the value is now allowed for.
812    
813    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
814        For "fr", it uses the Windows-specific input and output files.
815    
816    14. If (*THEN) appeared in a group that was called recursively or as a
817        subroutine, it did not work as intended. [But see next item.]
818    
819    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
820        pattern fragments (but not containing any | characters). If A and B are
821        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
822        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
823        D. In other words, Perl considers parentheses that do not contain any |
824        characters to be part of a surrounding alternative, whereas PCRE was
825        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
826        differently. PCRE now behaves in the same way as Perl, except in the case
827        of subroutine/recursion calls such as (?1) which have in any case always
828        been different (but PCRE had them first :-).
829    
830    16. Related to 15 above: Perl does not treat the | in a conditional group as
831        creating alternatives. Such a group is treated in the same way as an
832        ordinary group without any | characters when processing (*THEN). PCRE has
833        been changed to match Perl's behaviour.
834    
835    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
836        RunGrepTest script failed.
837    
838    18. Change 22 for version 13 caused atomic groups to use more stack. This is
839        inevitable for groups that contain captures, but it can lead to a lot of
840        stack use in large patterns. The old behaviour has been restored for atomic
841        groups that do not contain any capturing parentheses.
842    
843    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
844        suppress the check for a minimum subject length at run time. (If it was
845        given to pcre_exec() or pcre_dfa_exec() it did work.)
846    
847    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
848        fail to work when decoding hex characters in data strings in EBCDIC
849        environments.
850    
851    21. It appears that in at least one Mac OS environment, the isxdigit() function
852        is implemented as a macro that evaluates to its argument more than once,
853        contravening the C 90 Standard (I haven't checked a later standard). There
854        was an instance in pcretest which caused it to go wrong when processing
855        \x{...} escapes in subject strings. The has been rewritten to avoid using
856        things like p++ in the argument of isxdigit().
857    
858    
859    Version 8.13 16-Aug-2011
860  ------------------------  ------------------------
861    
862  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 875  Version 8.13 30-Apr-2011
875      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
876      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
877      left).      left).
878    
879  5.  Comprehensive information about what went wrong is now returned by  5.  Comprehensive information about what went wrong is now returned by
880      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
881      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
882      the failing character and a reason code are placed in the vector.      the failing character and a reason code are placed in the vector.
883    
884  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
885      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
886      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
887      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
888      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
889    
890  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
891      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
892      failure, the offset and reason code are output.      failure, the offset and reason code are output.
893    
894  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
895      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
896      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
897      two characters as a single entity when going forwards), conflicts with the      two characters as a single entity when going forwards), conflicts with the
898      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
899      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
900      has been changed.      has been changed.
901    
902  9.  Some internal refactoring has changed the processing so that the handling  9.  Some internal refactoring has changed the processing so that the handling
903      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
904      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
905      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,
906      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
907      argument for the match() function, which reduces its stack requirements      argument for the match() function, which reduces its stack requirements
908      slightly. This change also fixes an incompatibility with Perl: the pattern      slightly. This change also fixes an incompatibility with Perl: the pattern
909      (?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.
910    
911  10. More internal refactoring has drastically reduced the number of recursive  10. More internal refactoring has drastically reduced the number of recursive
912      calls to match() for possessively repeated groups such as (abc)++ when      calls to match() for possessively repeated groups such as (abc)++ when
913      using pcre_exec().      using pcre_exec().
914    
915  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
916      discovered and fixed:      discovered and fixed:
917    
918      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
919      (a|)*(?1) gave a compile-time internal error.      (a|)*(?1) gave a compile-time internal error.
920      ((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.
921      (^a|^)+   was not marked as anchored.      (^a|^)+   was not marked as anchored.
922      (.*a|.*)+ was not marked as matching at start or after a newline.      (.*a|.*)+ was not marked as matching at start or after a newline.
923    
924  12. Yet more internal refactoring has removed another argument from the match()  12. Yet more internal refactoring has removed another argument from the match()
925      function. Special calls to this function are now indicated by setting a      function. Special calls to this function are now indicated by setting a
926      value in a variable in the "match data" data block.      value in a variable in the "match data" data block.
927    
928  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
929      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
930      ones are added and accidentally left out of pcre_study(), testing should      ones are added and accidentally left out of pcre_study(), testing should
931      pick them up.      pick them up.
932    
933  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
934      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
935      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
936      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
937      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
938      and thereby test pcre_study() more easily.      study enabled, and thereby test pcre_study() more easily. All the standard
939        tests are now run with and without -s (but some patterns can be marked as
940        "never study" - see 20 below).
941    
942  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
943      restoration of the capturing data to the outer values was not happening      restoration of the capturing data to the outer values was not happening
944      correctly.      correctly.
945    
946  16. If a recursively called subpattern ended with (*ACCEPT) and matched an  16. If a recursively called subpattern ended with (*ACCEPT) and matched an
947      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
948      pattern had matched an empty string, and so incorrectly returned a no      pattern had matched an empty string, and so incorrectly returned a no
949      match.      match.
950    
951    17. There was optimizing code for the last branch of non-capturing parentheses,
952        and also for the obeyed branch of a conditional subexpression, which used
953        tail recursion to cut down on stack usage. Unfortunately, now that there is
954        the possibility of (*THEN) occurring in these branches, tail recursion is
955        no longer possible because the return has to be checked for (*THEN). These
956        two optimizations have therefore been removed. [But see 8.20/11 above.]
957    
958    18. If a pattern containing \R was studied, it was assumed that \R always
959        matched two bytes, thus causing the minimum subject length to be
960        incorrectly computed because \R can also match just one byte.
961    
962    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
963        was incorrectly computed.
964    
965    20. If /S is present twice on a test pattern in pcretest input, it now
966        *disables* studying, thereby overriding the use of -s on the command line
967        (see 14 above). This is necessary for one or two tests to keep the output
968        identical in both cases.
969    
970    21. When (*ACCEPT) was used in an assertion that matched an empty string and
971        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
972    
973    22. When an atomic group that contained a capturing parenthesis was
974        successfully matched, but the branch in which it appeared failed, the
975        capturing was not being forgotten if a higher numbered group was later
976        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
977        group 1 to "a", when in fact it should be unset. This applied to multi-
978        branched capturing and non-capturing groups, repeated or not, and also to
979        positive assertions (capturing in negative assertions does not happen
980        in PCRE) and also to nested atomic groups.
981    
982    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
983        subject after a captured substring, to make it easier to tell which of a
984        number of identical substrings has been captured.
985    
986    24. The way atomic groups are processed by pcre_exec() has been changed so that
987        if they are repeated, backtracking one repetition now resets captured
988        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
989        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
990        "aaa". Previously, it would have been "a". As part of this code
991        refactoring, the way recursive calls are handled has also been changed.
992    
993    25. If an assertion condition captured any substrings, they were not passed
994        back unless some other capturing happened later. For example, if
995        (?(?=(a))a) was matched against "a", no capturing was returned.
996    
997    26. When studying a pattern that contained subroutine calls or assertions,
998        the code for finding the minimum length of a possible match was handling
999        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1000        group 1 called group 2 while simultaneously a separate group 2 called group
1001        1). A stack overflow occurred in this case. I have fixed this by limiting
1002        the recursion depth to 10.
1003    
1004    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1005        Fortmann. This supports explicit test numbers on the command line, and has
1006        argument validation and error reporting.
1007    
1008    28. An instance of \X with an unlimited repeat could fail if at any point the
1009        first character it looked at was a mark character.
1010    
1011    29. Some minor code refactoring concerning Unicode properties and scripts
1012        should reduce the stack requirement of match() slightly.
1013    
1014    30. Added the '=' option to pcretest to check the setting of unused capturing
1015        slots at the end of the pattern, which are documented as being -1, but are
1016        not included in the return count.
1017    
1018    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1019        compiled something random. Now it gives a compile-time error (as does
1020        Perl).
1021    
1022    32. A *MARK encountered during the processing of a positive assertion is now
1023        recorded and passed back (compatible with Perl).
1024    
1025    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1026        had alternative anchored branches, the search for a second match in a line
1027        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1028        matched the line "0102" twice. The same bug affected patterns that started
1029        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1030        twice.
1031    
1032    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1033        does, and because of capturing effects, quantifying parenthesized
1034        assertions may at times be useful. Quantifiers are now allowed for
1035        parenthesized assertions.
1036    
1037    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1038    
1039    36. \g was being checked for fancy things in a character class, when it should
1040        just be a literal "g".
1041    
1042    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1043        appearance of a nested POSIX class supersedes an apparent external class.
1044        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1045        unescaped square brackets may also appear as part of class names. For
1046        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1047        more like Perl. (But see 8.20/1 above.)
1048    
1049    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1050        was because it thought it was \N{name}, which is not supported).
1051    
1052    39. Add minix to OS list not supporting the -S option in pcretest.
1053    
1054    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1055        cannot analyze patterns in sufficient detail to catch mutual recursions
1056        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1057        subgroup is called recursively as a subpattern for a second time at the
1058        same position in the subject string. In previous releases this might have
1059        been caught by the recursion limit, or it might have run out of stack.
1060    
1061    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1062        happen only once. PCRE was, however incorrectly giving a compile time error
1063        "recursive call could loop indefinitely" because it cannot analyze the
1064        pattern in sufficient detail. The compile time test no longer happens when
1065        PCRE is compiling a conditional subpattern, but actual runaway loops are
1066        now caught at runtime (see 40 above).
1067    
1068    42. It seems that Perl allows any characters other than a closing parenthesis
1069        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1070        has been changed to be the same.
1071    
1072    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1073        as not to get warnings when autogen.sh is called. Also changed
1074        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1075    
1076    44. To help people who use pcregrep to scan files containing exceedingly long
1077        lines, the following changes have been made:
1078    
1079        (a) The default value of the buffer size parameter has been increased from
1080            8K to 20K. (The actual buffer used is three times this size.)
1081    
1082        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1083            PCRE is built.
1084    
1085        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1086            to be set at run time.
1087    
1088        (d) Numerical values in pcregrep options can be followed by K or M, for
1089            example --buffer-size=50K.
1090    
1091        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1092            given and the return code is set to 2.
1093    
1094    45. Add a pointer to the latest mark to the callout data block.
1095    
1096    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1097        partial match of an empty string instead of no match. This was specific to
1098        the use of ".".
1099    
1100    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1101        complete match instead of a partial match. This bug was dependent on both
1102        the PCRE_UTF8 and PCRE_DOTALL options being set.
1103    
1104    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1105        starting byte set, because \b was not being ignored.
1106    
1107    
1108  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
1109  ------------------------  ------------------------
# Line 742  Version 7.9 11-Apr-09 Line 1755  Version 7.9 11-Apr-09
1755  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
1756      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
1757      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1758      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1759        8.33.]
1760    
1761  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
1762      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 1999  Version 7.7 07-May-08
1999      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2000      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2001      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2002      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2003      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2004      was subsequently set up correctly.)      was subsequently set up correctly.)
2005    

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