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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  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    16. Unicode character properties were updated from Unicode 6.3.0.
84    
85    17. The compile-time code for auto-possessification has been refactored, based
86        on a patch by Zoltan Herczeg. It now happens after instead of during
87        compilation. The code is cleaner, and more cases are handled. The option
88        PCRE_NO_AUTO_POSSESSIFY is added for testing purposes, and the -O and /O
89        options in pcretest are provided to set it.
90    
91    18. The character VT has been added to the set of characters that match \s and
92        are generally treated as white space, following this same change in Perl
93        5.18. There is now no difference between "Perl space" and "POSIX space".
94    
95    19. The code for checking named groups as conditions, either for being set or
96        for being recursed, has been refactored (this is related to 14 and 15
97        above). Processing unduplicated named groups should now be as fast at
98        numerical groups, and processing duplicated groups should be faster than
99        before.
100    
101    20. Two patches to the CMake build system, by Alexander Barkov:
102    
103          (1) Replace the "source" command by "." in CMakeLists.txt because
104              "source" is a bash-ism.
105    
106          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
107              without these the CMake build does not work on Solaris.
108    
109    21. Perl has changed its handling of \8 and \9. If there is no previously
110        encountered capturing group of those numbers, they are treated as the
111        literal characters 8 and 9 instead of a binary zero followed by the
112        literals. PCRE now does the same.
113    
114    22. Following Perl, added \o{} to specify codepoints in octal, making it
115        possible to specify values greater than 0777 and also making them
116        unambiguous.
117    
118    23. Perl now gives an error for missing closing braces after \x{... instead of
119        treating the string as literal. PCRE now does the same.
120    
121    24. RunTest used to grumble if an inappropriate test was selected explicitly,
122        but just skip it when running all tests. This make it awkward to run ranges
123        of tests when one of them was inappropriate. Now it just skips any
124        inappropriate tests, as it always did when running all tests.
125    
126    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
127        character types such as \d or \w, too many callouts were inserted, and the
128        data that they returned was rubbish.
129    
130    26. In UCP mode, \s was not matching two of the characters that Perl matches,
131        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
132        were matched by \h. The code has now been refactored so that the lists of
133        the horizontal and vertical whitespace characters used for \h and \v (which
134        are defined only in one place) are now also used for \s.
135    
136    27. Add JIT support for the 64 bit TileGX architecture.
137        Patch by Jiong Wang (Tilera Corporation).
138    
139    28. Possessive quantifiers for classes (both explicit and automatically
140        generated) now use special opcodes instead of wrapping in ONCE brackets.
141    
142    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
143        (because it's meaningless), this was not happening when PCRE_CASELESS was
144        set. Not wrong, but inefficient.
145    
146    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
147        properties for \w, \d, etc) is present in a test regex. Otherwise if the
148        test contains no characters greater than 255, Perl doesn't realise it
149        should be using Unicode semantics.
150    
151    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
152        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
153        does in Unicode mode.
154    
155    32. Added the "forbid" facility to pcretest so that putting tests into the
156        wrong test files can sometimes be quickly detected.
157    
158    33. There is now a limit (default 250) on the depth of nesting of parentheses.
159        This limit is imposed to control the amount of system stack used at compile
160        time. It can be changed at build time by --with-parens-nest-limit=xxx or
161        the equivalent in CMake.
162    
163    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
164        errors. Perl warns for these when in warning mode, but PCRE has no facility
165        for giving warnings.
166    
167    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
168        However, this was not working for (?!) because it is optimized to (*FAIL),
169        for which PCRE does not allow quantifiers. The optimization is now disabled
170        when a quantifier follows (?!). I can't see any use for this, but it makes
171        things uniform.
172    
173    36. Perl no longer allows group names to start with digits, so I have made this
174        change also in PCRE. It simplifies the code a bit.
175    
176    
177    Version 8.33 28-May-2013
178    ------------------------
179    
180    1.  Added 'U' to some constants that are compared to unsigned integers, to
181        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
182        variables that are added to signed variables, to ensure the result is
183        signed and can be negated.
184    
185    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
186        CMake config files.
187    
188    3.  Revise the creation of config.h.generic so that all boolean macros are
189        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
190        overriding via -D on the command line possible.
191    
192    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
193        to unsigned int is reported to make a quite noticeable speed difference in
194        a specific Windows environment. Testing on Linux did also appear to show
195        some benefit (and it is clearly not harmful). Also fixed the definition of
196        Xop which should be unsigned.
197    
198    5.  Related to (4), changing the definition of the intermediate variable cc
199        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
200        improvements.
201    
202    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
203        unnecessary spaces.
204    
205    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
206        and later.
207    
208    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
209    
210    9.  Optimizing fast_forward_start_bits in JIT.
211    
212    10. Adding support for callouts in JIT, and fixing some issues revealed
213        during this work. Namely:
214    
215        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
216    
217        (b) Minimum length was not checked before the matching is started.
218    
219    11. The value of capture_last that is passed to callouts was incorrect in some
220        cases when there was a capture on one path that was subsequently abandoned
221        after a backtrack. Also, the capture_last value is now reset after a
222        recursion, since all captures are also reset in this case.
223    
224    12. The interpreter no longer returns the "too many substrings" error in the
225        case when an overflowing capture is in a branch that is subsequently
226        abandoned after a backtrack.
227    
228    13. In the pathological case when an offset vector of size 2 is used, pcretest
229        now prints out the matched string after a yield of 0 or 1.
230    
231    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
232        Only supported by the JIT compiler at the moment.
233    
234    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
235    
236    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
237        offset of the starting point of the matching process, provided the offsets
238        vector is large enough.
239    
240    17. The \A escape now records a lookbehind value of 1, though its execution
241        does not actually inspect the previous character. This is to ensure that,
242        in partial multi-segment matching, at least one character from the old
243        segment is retained when a new segment is processed. Otherwise, if there
244        are no lookbehinds in the pattern, \A might match incorrectly at the start
245        of a new segment.
246    
247    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
248    
249    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
250        gives some modest performance improvement in 8-bit mode.
251    
252    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
253        be expressed in certain programming languages using Universal Character
254        Names.
255    
256    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
257        which points out that "non characters" are not "characters that may not
258        appear in Unicode strings" but rather "characters that are reserved for
259        internal use and have only local meaning".
260    
261    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
262        there was a conditional group that depended on an assertion, if the
263        assertion was false, the callout that immediately followed the alternation
264        in the condition was skipped when pcre_exec() was used for matching.
265    
266    23. Allow an explicit callout to be inserted before an assertion that is the
267        condition for a conditional group, for compatibility with automatic
268        callouts, which always insert a callout at this point.
269    
270    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
271        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
272    
273    25. (*PRUNE) is now supported by the JIT compiler.
274    
275    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
276    
277    27. Fix the case where there are two or more SKIPs with arguments that may be
278        ignored.
279    
280    28. (*SKIP) is now supported by the JIT compiler.
281    
282    29. (*THEN) is now supported by the JIT compiler.
283    
284    30. Update RunTest with additional test selector options.
285    
286    31. The way PCRE handles backtracking verbs has been changed in two ways.
287    
288        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
289        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
290        backtracking. In some cases this makes it more Perl-compatible, but Perl's
291        rather obscure rules do not always do the same thing.
292    
293        (2) Previously, backtracking verbs were confined within assertions. This is
294        no longer the case for positive assertions, except for (*ACCEPT). Again,
295        this sometimes improves Perl compatibility, and sometimes does not.
296    
297    32. A number of tests that were in test 2 because Perl did things differently
298        have been moved to test 1, because either Perl or PCRE has changed, and
299        these tests are now compatible.
300    
301    32. Backtracking control verbs are now handled in the same way in JIT and
302        interpreter.
303    
304    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
305        contained a forward subroutine reference caused a compile error.
306    
307    34. Auto-detect and optimize limited repetitions in JIT.
308    
309    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
310        blocking (*UTF) etc.
311    
312    36. In the interpreter, maximizing pattern repetitions for characters and
313        character types now use tail recursion, which reduces stack usage.
314    
315    37. The value of the max lookbehind was not correctly preserved if a compiled
316        and saved regex was reloaded on a host of different endianness.
317    
318    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
319        of the compiled pattern block, expand the flags field from 16 to 32 bits
320        because it was almost full.
321    
322    39. Try madvise first before posix_madvise.
323    
324    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
325        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
326        original change locked out all matches of empty strings. This has been
327        changed so that one match of an empty string per line is recognized.
328        Subsequent searches on the same line (for colouring or for --only-matching,
329        for example) do not recognize empty strings.
330    
331    41. Applied a user patch to fix a number of spelling mistakes in comments.
332    
333    42. Data lines longer than 65536 caused pcretest to crash.
334    
335    43. Clarified the data type for length and startoffset arguments for pcre_exec
336        and pcre_dfa_exec in the function-specific man pages, where they were
337        explicitly stated to be in bytes, never having been updated. I also added
338        some clarification to the pcreapi man page.
339    
340    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
341        a segmentation fault.
342    
343    
344    Version 8.32 30-November-2012
345    -----------------------------
346    
347    1.  Improved JIT compiler optimizations for first character search and single
348        character iterators.
349    
350    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
351        Patch by Daniel Richard G.
352    
353    3.  Single character iterator optimizations in the JIT compiler.
354    
355    4.  Improved JIT compiler optimizations for character ranges.
356    
357    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
358        Reported by Giuseppe D'Angelo.
359    
360    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
361        of a line, was being set incorrectly in cases where .* appeared inside
362        atomic brackets at the start of a pattern, or where there was a subsequent
363        *PRUNE or *SKIP.
364    
365    7.  Improved instruction cache flush for POWER/PowerPC.
366        Patch by Daniel Richard G.
367    
368    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
369        grep:
370    
371        (a) There is now no limit to the number of patterns to be matched.
372    
373        (b) An error is given if a pattern is too long.
374    
375        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
376            are now supported.
377    
378        (d) --exclude-from and --include-from (multiple use) have been added.
379    
380        (e) Exclusions and inclusions now apply to all files and directories, not
381            just to those obtained from scanning a directory recursively.
382    
383        (f) Multiple uses of -f and --file-list are now supported.
384    
385        (g) In a Windows environment, the default for -d has been changed from
386            "read" (the GNU grep default) to "skip", because otherwise the presence
387            of a directory in the file list provokes an error.
388    
389        (h) The documentation has been revised and clarified in places.
390    
391    9.  Improve the matching speed of capturing brackets.
392    
393    10. Changed the meaning of \X so that it now matches a Unicode extended
394        grapheme cluster.
395    
396    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
397        out POSIX threads when JIT support is configured.
398    
399    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
400    
401    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
402        structure could go wrong in environments where size_t is not the same size
403        as int.
404    
405    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
406        set.
407    
408    15. The EBCDIC support had decayed; later updates to the code had included
409        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
410        general tidy up of EBCDIC-related issues, and the documentation was also
411        not quite right. There is now a test that can be run on ASCII systems to
412        check some of the EBCDIC-related things (but is it not a full test).
413    
414    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
415        in a small tidy to the code.
416    
417    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
418    
419    18. If the --only-matching (-o) option in pcregrep is specified multiple
420        times, each one causes appropriate output. For example, -o1 -o2 outputs the
421        substrings matched by the 1st and 2nd capturing parentheses. A separating
422        string can be specified by --om-separator (default empty).
423    
424    19. Improving the first n character searches.
425    
426    20. Turn case lists for horizontal and vertical white space into macros so that
427        they are defined only once.
428    
429    21. This set of changes together give more compatible Unicode case-folding
430        behaviour for characters that have more than one other case when UCP
431        support is available.
432    
433        (a) The Unicode property table now has offsets into a new table of sets of
434            three or more characters that are case-equivalent. The MultiStage2.py
435            script that generates these tables (the pcre_ucd.c file) now scans
436            CaseFolding.txt instead of UnicodeData.txt for character case
437            information.
438    
439        (b) The code for adding characters or ranges of characters to a character
440            class has been abstracted into a generalized function that also handles
441            case-independence. In UTF-mode with UCP support, this uses the new data
442            to handle characters with more than one other case.
443    
444        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
445            whose other case is greater than 256 are now correctly matched
446            caselessly. Previously, the high codepoint matched the low one, but not
447            vice versa.
448    
449        (d) The processing of \h, \H, \v, and \ in character classes now makes use
450            of the new class addition function, using character lists defined as
451            macros alongside the case definitions of 20 above.
452    
453        (e) Caseless back references now work with characters that have more than
454            one other case.
455    
456        (f) General caseless matching of characters with more than one other case
457            is supported.
458    
459    22. Unicode character properties were updated from Unicode 6.2.0
460    
461    23. Improved CMake support under Windows. Patch by Daniel Richard G.
462    
463    24. Add support for 32-bit character strings, and UTF-32
464    
465    25. Major JIT compiler update (code refactoring and bugfixing).
466        Experimental Sparc 32 support is added.
467    
468    26. Applied a modified version of Daniel Richard G's patch to create
469        pcre.h.generic and config.h.generic by "make" instead of in the
470        PrepareRelease script.
471    
472    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
473        pcre_compile.c when checking for a zero character.
474    
475    28. Introducing a native interface for JIT. Through this interface, the compiled
476        machine code can be directly executed. The purpose of this interface is to
477        provide fast pattern matching, so several sanity checks are not performed.
478        However, feature tests are still performed. The new interface provides
479        1.4x speedup compared to the old one.
480    
481    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
482        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
483        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
484    
485    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
486        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
487        the "old" RFC 2279). Instead, it ended up passing a negative length to
488        pcre_exec().
489    
490    31. Add support for GCC's visibility feature to hide internal functions.
491    
492    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
493        "unknown -C option" after outputting 0 or 1.
494    
495    33. There is now support for generating a code coverage report for the test
496        suite in environments where gcc is the compiler and lcov is installed. This
497        is mainly for the benefit of the developers.
498    
499    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
500        unaddressable using valgrind annotations, allowing valgrind to detect
501        invalid memory accesses. This is mainly for the benefit of the developers.
502    
503    25. (*UTF) can now be used to start a pattern in any of the three libraries.
504    
505    26. Give configure error if --enable-cpp but no C++ compiler found.
506    
507    
508    Version 8.31 06-July-2012
509    -------------------------
510    
511    1.  Fixing a wrong JIT test case and some compiler warnings.
512    
513    2.  Removed a bashism from the RunTest script.
514    
515    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
516        to unsigned type, result still unsigned" that was given by an MS compiler
517        on encountering the code "-sizeof(xxx)".
518    
519    4.  Partial matching support is added to the JIT compiler.
520    
521    5.  Fixed several bugs concerned with partial matching of items that consist
522        of more than one character:
523    
524        (a) /^(..)\1/ did not partially match "aba" because checking references was
525            done on an "all or nothing" basis. This also applied to repeated
526            references.
527    
528        (b) \R did not give a hard partial match if \r was found at the end of the
529            subject.
530    
531        (c) \X did not give a hard partial match after matching one or more
532            characters at the end of the subject.
533    
534        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
535            a partial match for the string "\r".
536    
537        (e) When newline was set to CRLF, the metacharacter "." did not recognize
538            a partial match for a CR character at the end of the subject string.
539    
540    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
541        running pcretest, the text "(JIT)" added to the output whenever JIT is
542        actually used to run the match.
543    
544    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
545        or /S+[+] with a digit between 1 and 7.
546    
547    8.  OP_NOT now supports any UTF character not just single-byte ones.
548    
549    9.  (*MARK) control verb is now supported by the JIT compiler.
550    
551    10. The command "./RunTest list" lists the available tests without actually
552        running any of them. (Because I keep forgetting what they all are.)
553    
554    11. Add PCRE_INFO_MAXLOOKBEHIND.
555    
556    12. Applied a (slightly modified) user-supplied patch that improves performance
557        when the heap is used for recursion (compiled with --disable-stack-for-
558        recursion). Instead of malloc and free for each heap frame each time a
559        logical recursion happens, frames are retained on a chain and re-used where
560        possible. This sometimes gives as much as 30% improvement.
561    
562    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
563        call.
564    
565    14. As documented, (*COMMIT) is now confined to within a positive assertion.
566    
567    15. It is now possible to link pcretest with libedit as an alternative to
568        libreadline.
569    
570    16. (*COMMIT) control verb is now supported by the JIT compiler.
571    
572    17. The Unicode data tables have been updated to Unicode 6.1.0.
573    
574    18. Added --file-list option to pcregrep.
575    
576    19. Added binary file support to pcregrep, including the -a, --binary-files,
577        -I, and --text options.
578    
579    20. The madvise function is renamed for posix_madvise for QNX compatibility
580        reasons. Fixed by Giuseppe D'Angelo.
581    
582    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
583    
584    22. Changed the option for creating symbolic links for 16-bit man pages from
585        -s to -sf so that re-installing does not cause issues.
586    
587    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
588    
589    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
590        matches in certain environments (the workspace was not being correctly
591        retained). Also added to pcre_dfa_exec() a simple plausibility check on
592        some of the workspace data at the beginning of a restart.
593    
594    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
595        was not doing so when it should - probably a typo introduced by SVN 528
596        (change 8.10/14).
597    
598    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
599        \w+ when the character tables indicated that \x{c4} was a word character.
600        There were several related cases, all because the tests for doing a table
601        lookup were testing for characters less than 127 instead of 255.
602    
603    27. If a pattern contains capturing parentheses that are not used in a match,
604        their slots in the ovector are set to -1. For those that are higher than
605        any matched groups, this happens at the end of processing. In the case when
606        there were back references that the ovector was too small to contain
607        (causing temporary malloc'd memory to be used during matching), and the
608        highest capturing number was not used, memory off the end of the ovector
609        was incorrectly being set to -1. (It was using the size of the temporary
610        memory instead of the true size.)
611    
612    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
613        ovector size, it uses memory at the end of the block that it has got.
614    
615    29. Check for an overlong MARK name and give an error at compile time. The
616        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
617    
618    30. JIT compiler update.
619    
620    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
621        Rill for the patch.
622    
623    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
624    
625    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
626    
627    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
628        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
629        was enabled.
630    
631    35. Improve JIT code generation for greedy plus quantifier.
632    
633    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
634        1 to "aa" instead of to an empty string. The bug affected repeated groups
635        that could potentially match an empty string.
636    
637    37. Optimizing single character iterators in JIT.
638    
639    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
640        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
641        codepoints that are too big for the mode are faulted, and in a UTF mode,
642        disallowed codepoints are also faulted.
643    
644    39. If PCRE was compiled with UTF support, in three places in the DFA
645        matcher there was code that should only have been obeyed in UTF mode, but
646        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
647        processing when bytes with values greater than 127 were present. In 16-bit
648        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
649        both cases the values are those that cannot be the first data item in a UTF
650        character. The three items that might have provoked this were recursions,
651        possessively repeated groups, and atomic groups.
652    
653    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
654        and pcregrep, because some OS require shared objects to be explicitly
655        passed to ld, causing the link step to fail if they are not.
656    
657    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
658        mode, patterns that started with \h* or \R* might be incorrectly matched.
659    
660    
661    Version 8.30 04-February-2012
662    -----------------------------
663    
664    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
665        name is defined in ctype.h.
666    
667    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
668        only in quite long subpatterns.
669    
670    3.  Removed the function pcre_info(), which has been obsolete and deprecated
671        since it was replaced by pcre_fullinfo() in February 2000.
672    
673    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
674        match a (*MARK), and the match failed at the start of the subject, a
675        reference to memory before the start of the subject could occur. This bug
676        was introduced by fix 17 of release 8.21.
677    
678    5.  A reference to an unset group with zero minimum repetition was giving
679        totally wrong answers (in non-JavaScript-compatibility mode). For example,
680        /(another)?(\1?)test/ matched against "hello world test". This bug was
681        introduced in release 8.13.
682    
683    6.  Add support for 16-bit character strings (a large amount of work involving
684        many changes and refactorings).
685    
686    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
687        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
688        from a file.
689    
690    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
691        rounding is not applied in this particular case).
692    
693    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
694        if they appear, or are escaped, in patterns.
695    
696    10. Get rid of a number of -Wunused-but-set-variable warnings.
697    
698    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
699        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
700        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
701        also returns the mark "x". This bug applied to capturing parentheses,
702        non-capturing parentheses, and atomic parentheses. It also applied to some
703        assertions.
704    
705    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
706        information out of configure.ac instead of relying on pcre.h.generic, which
707        is not stored in the repository.
708    
709    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
710        -lreadline.
711    
712    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
713    
714    15. Applied Graycode's patch to put the top-level frame on the stack rather
715        than the heap when not using the stack for recursion. This gives a
716        performance improvement in many cases when recursion is not deep.
717    
718    16. Experimental code added to "pcretest -C" to output the stack frame size.
719    
720    
721    Version 8.21 12-Dec-2011
722    ------------------------
723    
724    1.  Updating the JIT compiler.
725    
726    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
727        are added as well.
728    
729    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
730        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
731        calling _pcre_jit_exec. Some extra comments are added.
732    
733    4.  (*MARK) settings inside atomic groups that do not contain any capturing
734        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
735        was introduced by change 18 for 8.20.
736    
737    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
738        ECMA-262 standard.
739    
740    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
741        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
742        This bug was probably introduced by change 9 of 8.13.
743    
744    7.  While fixing 6 above, I noticed that a number of other items were being
745        incorrectly rejected as "not fixed length". This arose partly because newer
746        opcodes had not been added to the fixed-length checking code. I have (a)
747        corrected the bug and added tests for these items, and (b) arranged for an
748        error to occur if an unknown opcode is encountered while checking for fixed
749        length instead of just assuming "not fixed length". The items that were
750        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
751        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
752        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
753    
754    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
755        being incorrectly compiled and would have given unpredicatble results.
756    
757    9.  A possessively repeated subpattern with minimum repeat count greater than
758        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
759        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
760        the first (A) could occur when it should not.
761    
762    10. Add a cast and remove a redundant test from the code.
763    
764    11. JIT should use pcre_malloc/pcre_free for allocation.
765    
766    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
767        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
768        is anything other than /usr, -L is still shown).
769    
770    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
771    
772    14. Perl does not support \N without a following name in a [] class; PCRE now
773        also gives an error.
774    
775    15. If a forward reference was repeated with an upper limit of around 2000,
776        it caused the error "internal error: overran compiling workspace". The
777        maximum number of forward references (including repeats) was limited by the
778        internal workspace, and dependent on the LINK_SIZE. The code has been
779        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
780        the default depends on LINK_SIZE. There is a new upper limit (for safety)
781        of around 200,000 forward references. While doing this, I also speeded up
782        the filling in of repeated forward references.
783    
784    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
785        incorrectly expecting the subject to contain another "a" after the start.
786    
787    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
788        in the match, the SKIP should be ignored. This was not happening; instead
789        the SKIP was being treated as NOMATCH. For patterns such as
790        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
791        tested.
792    
793    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
794        now much more compatible with Perl, in particular in cases where the result
795        is a non-match for a non-anchored pattern. For example, if
796        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
797        "m", where previously it did not return a name. A side effect of this
798        change is that for partial matches, the last encountered mark name is
799        returned, as for non matches. A number of tests that were previously not
800        Perl-compatible have been moved into the Perl-compatible test files. The
801        refactoring has had the pleasing side effect of removing one argument from
802        the match() function, thus reducing its stack requirements.
803    
804    19. If the /S+ option was used in pcretest to study a pattern using JIT,
805        subsequent uses of /S (without +) incorrectly behaved like /S+.
806    
807    21. Retrieve executable code size support for the JIT compiler and fixing
808        some warnings.
809    
810    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
811        not work when the shorter character appeared right at the end of the
812        subject string.
813    
814    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
815        systems.
816    
817    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
818        output it when the /M option is used in pcretest.
819    
820    25. The CheckMan script was not being included in the distribution. Also, added
821        an explicit "perl" to run Perl scripts from the PrepareRelease script
822        because this is reportedly needed in Windows.
823    
824    26. If study data was being save in a file and studying had not found a set of
825        "starts with" bytes for the pattern, the data written to the file (though
826        never used) was taken from uninitialized memory and so caused valgrind to
827        complain.
828    
829    27. Updated RunTest.bat as provided by Sheri Pierce.
830    
831    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
832    
833    29. Computation of memory usage for the table of capturing group names was
834        giving an unnecessarily large value.
835    
836    
837    Version 8.20 21-Oct-2011
838    ------------------------
839    
840    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
841        a POSIX class. After further experiments with Perl, which convinced me that
842        Perl has bugs and confusions, a closing square bracket is no longer allowed
843        in a POSIX name. This bug also affected patterns with classes that started
844        with full stops.
845    
846    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
847        captured substring, but while checking the failing first alternative,
848        substring 1 is temporarily captured. If the output vector supplied to
849        pcre_exec() was not big enough for this capture, the yield of the function
850        was still zero ("insufficient space for captured substrings"). This cannot
851        be totally fixed without adding another stack variable, which seems a lot
852        of expense for a edge case. However, I have improved the situation in cases
853        such as /(a)(b)x|abc/ matched against "abc", where the return code
854        indicates that fewer than the maximum number of slots in the ovector have
855        been set.
856    
857    3.  Related to (2) above: when there are more back references in a pattern than
858        slots in the output vector, pcre_exec() uses temporary memory during
859        matching, and copies in the captures as far as possible afterwards. It was
860        using the entire output vector, but this conflicts with the specification
861        that only 2/3 is used for passing back captured substrings. Now it uses
862        only the first 2/3, for compatibility. This is, of course, another edge
863        case.
864    
865    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
866        main code base, and can be used by building with --enable-jit. When this is
867        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
868        runtime --no-jit option is given.
869    
870    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
871        ovector, the return from the function was zero, implying that there were
872        other matches that did not fit. The correct "exactly full" value is now
873        returned.
874    
875    6.  If a subpattern that was called recursively or as a subroutine contained
876        (*PRUNE) or any other control that caused it to give a non-standard return,
877        invalid errors such as "Error -26 (nested recursion at the same subject
878        position)" or even infinite loops could occur.
879    
880    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
881        computing the minimum length on reaching *ACCEPT, and so ended up with the
882        wrong value of 1 rather than 0. Further investigation indicates that
883        computing a minimum subject length in the presence of *ACCEPT is difficult
884        (think back references, subroutine calls), and so I have changed the code
885        so that no minimum is registered for a pattern that contains *ACCEPT.
886    
887    8.  If (*THEN) was present in the first (true) branch of a conditional group,
888        it was not handled as intended. [But see 16 below.]
889    
890    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
891        Sheri Pierce.
892    
893    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
894        the first byte in a match must be "a".
895    
896    11. Change 17 for 8.13 increased the recursion depth for patterns like
897        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
898        pattern contains any instances of (*THEN). If it does not, the old
899        optimizations are restored. It would be nice to do this on a per-group
900        basis, but at the moment that is not feasible.
901    
902    12. In some environments, the output of pcretest -C is CRLF terminated. This
903        broke RunTest's code that checks for the link size. A single white space
904        character after the value is now allowed for.
905    
906    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
907        For "fr", it uses the Windows-specific input and output files.
908    
909    14. If (*THEN) appeared in a group that was called recursively or as a
910        subroutine, it did not work as intended. [But see next item.]
911    
912    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
913        pattern fragments (but not containing any | characters). If A and B are
914        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
915        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
916        D. In other words, Perl considers parentheses that do not contain any |
917        characters to be part of a surrounding alternative, whereas PCRE was
918        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
919        differently. PCRE now behaves in the same way as Perl, except in the case
920        of subroutine/recursion calls such as (?1) which have in any case always
921        been different (but PCRE had them first :-).
922    
923    16. Related to 15 above: Perl does not treat the | in a conditional group as
924        creating alternatives. Such a group is treated in the same way as an
925        ordinary group without any | characters when processing (*THEN). PCRE has
926        been changed to match Perl's behaviour.
927    
928    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
929        RunGrepTest script failed.
930    
931    18. Change 22 for version 13 caused atomic groups to use more stack. This is
932        inevitable for groups that contain captures, but it can lead to a lot of
933        stack use in large patterns. The old behaviour has been restored for atomic
934        groups that do not contain any capturing parentheses.
935    
936    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
937        suppress the check for a minimum subject length at run time. (If it was
938        given to pcre_exec() or pcre_dfa_exec() it did work.)
939    
940    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
941        fail to work when decoding hex characters in data strings in EBCDIC
942        environments.
943    
944    21. It appears that in at least one Mac OS environment, the isxdigit() function
945        is implemented as a macro that evaluates to its argument more than once,
946        contravening the C 90 Standard (I haven't checked a later standard). There
947        was an instance in pcretest which caused it to go wrong when processing
948        \x{...} escapes in subject strings. The has been rewritten to avoid using
949        things like p++ in the argument of isxdigit().
950    
951    
952    Version 8.13 16-Aug-2011
953    ------------------------
954    
955    1.  The Unicode data tables have been updated to Unicode 6.0.0.
956    
957    2.  Two minor typos in pcre_internal.h have been fixed.
958    
959    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
960        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
961        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
962    
963    4.  There were a number of related bugs in the code for matching backrefences
964        caselessly in UTF-8 mode when codes for the characters concerned were
965        different numbers of bytes. For example, U+023A and U+2C65 are an upper
966        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
967        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
968        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
969        2-byte code at the end of the subject (it thought there wasn't enough data
970        left).
971    
972    5.  Comprehensive information about what went wrong is now returned by
973        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
974        as the output vector has at least 2 elements. The offset of the start of
975        the failing character and a reason code are placed in the vector.
976    
977    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
978        now returned is for the first byte of the failing character, instead of the
979        last byte inspected. This is an incompatible change, but I hope it is small
980        enough not to be a problem. It makes the returned offset consistent with
981        pcre_exec() and pcre_dfa_exec().
982    
983    7.  pcretest now gives a text phrase as well as the error number when
984        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
985        failure, the offset and reason code are output.
986    
987    8.  When \R was used with a maximizing quantifier it failed to skip backwards
988        over a \r\n pair if the subsequent match failed. Instead, it just skipped
989        back over a single character (\n). This seems wrong (because it treated the
990        two characters as a single entity when going forwards), conflicts with the
991        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
992        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
993        has been changed.
994    
995    9.  Some internal refactoring has changed the processing so that the handling
996        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
997        time (the PCRE_DOTALL option was changed this way some time ago: version
998        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
999        which was always a bit of a fudge. It also means that there is one less
1000        argument for the match() function, which reduces its stack requirements
1001        slightly. This change also fixes an incompatibility with Perl: the pattern
1002        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1003    
1004    10. More internal refactoring has drastically reduced the number of recursive
1005        calls to match() for possessively repeated groups such as (abc)++ when
1006        using pcre_exec().
1007    
1008    11. While implementing 10, a number of bugs in the handling of groups were
1009        discovered and fixed:
1010    
1011        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1012        (a|)*(?1) gave a compile-time internal error.
1013        ((a|)+)+  did not notice that the outer group could match an empty string.
1014        (^a|^)+   was not marked as anchored.
1015        (.*a|.*)+ was not marked as matching at start or after a newline.
1016    
1017    12. Yet more internal refactoring has removed another argument from the match()
1018        function. Special calls to this function are now indicated by setting a
1019        value in a variable in the "match data" data block.
1020    
1021    13. Be more explicit in pcre_study() instead of relying on "default" for
1022        opcodes that mean there is no starting character; this means that when new
1023        ones are added and accidentally left out of pcre_study(), testing should
1024        pick them up.
1025    
1026    14. The -s option of pcretest has been documented for ages as being an old
1027        synonym of -m (show memory usage). I have changed it to mean "force study
1028        for every regex", that is, assume /S for every regex. This is similar to -i
1029        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1030        using it. It makes it easier to run collections of tests with and without
1031        study enabled, and thereby test pcre_study() more easily. All the standard
1032        tests are now run with and without -s (but some patterns can be marked as
1033        "never study" - see 20 below).
1034    
1035    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1036        restoration of the capturing data to the outer values was not happening
1037        correctly.
1038    
1039    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1040        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1041        pattern had matched an empty string, and so incorrectly returned a no
1042        match.
1043    
1044    17. There was optimizing code for the last branch of non-capturing parentheses,
1045        and also for the obeyed branch of a conditional subexpression, which used
1046        tail recursion to cut down on stack usage. Unfortunately, now that there is
1047        the possibility of (*THEN) occurring in these branches, tail recursion is
1048        no longer possible because the return has to be checked for (*THEN). These
1049        two optimizations have therefore been removed. [But see 8.20/11 above.]
1050    
1051    18. If a pattern containing \R was studied, it was assumed that \R always
1052        matched two bytes, thus causing the minimum subject length to be
1053        incorrectly computed because \R can also match just one byte.
1054    
1055    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1056        was incorrectly computed.
1057    
1058    20. If /S is present twice on a test pattern in pcretest input, it now
1059        *disables* studying, thereby overriding the use of -s on the command line
1060        (see 14 above). This is necessary for one or two tests to keep the output
1061        identical in both cases.
1062    
1063    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1064        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1065    
1066    22. When an atomic group that contained a capturing parenthesis was
1067        successfully matched, but the branch in which it appeared failed, the
1068        capturing was not being forgotten if a higher numbered group was later
1069        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1070        group 1 to "a", when in fact it should be unset. This applied to multi-
1071        branched capturing and non-capturing groups, repeated or not, and also to
1072        positive assertions (capturing in negative assertions does not happen
1073        in PCRE) and also to nested atomic groups.
1074    
1075    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1076        subject after a captured substring, to make it easier to tell which of a
1077        number of identical substrings has been captured.
1078    
1079    24. The way atomic groups are processed by pcre_exec() has been changed so that
1080        if they are repeated, backtracking one repetition now resets captured
1081        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1082        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1083        "aaa". Previously, it would have been "a". As part of this code
1084        refactoring, the way recursive calls are handled has also been changed.
1085    
1086    25. If an assertion condition captured any substrings, they were not passed
1087        back unless some other capturing happened later. For example, if
1088        (?(?=(a))a) was matched against "a", no capturing was returned.
1089    
1090    26. When studying a pattern that contained subroutine calls or assertions,
1091        the code for finding the minimum length of a possible match was handling
1092        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1093        group 1 called group 2 while simultaneously a separate group 2 called group
1094        1). A stack overflow occurred in this case. I have fixed this by limiting
1095        the recursion depth to 10.
1096    
1097    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1098        Fortmann. This supports explicit test numbers on the command line, and has
1099        argument validation and error reporting.
1100    
1101    28. An instance of \X with an unlimited repeat could fail if at any point the
1102        first character it looked at was a mark character.
1103    
1104    29. Some minor code refactoring concerning Unicode properties and scripts
1105        should reduce the stack requirement of match() slightly.
1106    
1107    30. Added the '=' option to pcretest to check the setting of unused capturing
1108        slots at the end of the pattern, which are documented as being -1, but are
1109        not included in the return count.
1110    
1111    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1112        compiled something random. Now it gives a compile-time error (as does
1113        Perl).
1114    
1115    32. A *MARK encountered during the processing of a positive assertion is now
1116        recorded and passed back (compatible with Perl).
1117    
1118    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1119        had alternative anchored branches, the search for a second match in a line
1120        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1121        matched the line "0102" twice. The same bug affected patterns that started
1122        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1123        twice.
1124    
1125    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1126        does, and because of capturing effects, quantifying parenthesized
1127        assertions may at times be useful. Quantifiers are now allowed for
1128        parenthesized assertions.
1129    
1130    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1131    
1132    36. \g was being checked for fancy things in a character class, when it should
1133        just be a literal "g".
1134    
1135    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1136        appearance of a nested POSIX class supersedes an apparent external class.
1137        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1138        unescaped square brackets may also appear as part of class names. For
1139        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1140        more like Perl. (But see 8.20/1 above.)
1141    
1142    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1143        was because it thought it was \N{name}, which is not supported).
1144    
1145    39. Add minix to OS list not supporting the -S option in pcretest.
1146    
1147    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1148        cannot analyze patterns in sufficient detail to catch mutual recursions
1149        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1150        subgroup is called recursively as a subpattern for a second time at the
1151        same position in the subject string. In previous releases this might have
1152        been caught by the recursion limit, or it might have run out of stack.
1153    
1154    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1155        happen only once. PCRE was, however incorrectly giving a compile time error
1156        "recursive call could loop indefinitely" because it cannot analyze the
1157        pattern in sufficient detail. The compile time test no longer happens when
1158        PCRE is compiling a conditional subpattern, but actual runaway loops are
1159        now caught at runtime (see 40 above).
1160    
1161    42. It seems that Perl allows any characters other than a closing parenthesis
1162        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1163        has been changed to be the same.
1164    
1165    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1166        as not to get warnings when autogen.sh is called. Also changed
1167        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1168    
1169    44. To help people who use pcregrep to scan files containing exceedingly long
1170        lines, the following changes have been made:
1171    
1172        (a) The default value of the buffer size parameter has been increased from
1173            8K to 20K. (The actual buffer used is three times this size.)
1174    
1175        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1176            PCRE is built.
1177    
1178        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1179            to be set at run time.
1180    
1181        (d) Numerical values in pcregrep options can be followed by K or M, for
1182            example --buffer-size=50K.
1183    
1184        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1185            given and the return code is set to 2.
1186    
1187    45. Add a pointer to the latest mark to the callout data block.
1188    
1189    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1190        partial match of an empty string instead of no match. This was specific to
1191        the use of ".".
1192    
1193    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1194        complete match instead of a partial match. This bug was dependent on both
1195        the PCRE_UTF8 and PCRE_DOTALL options being set.
1196    
1197    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1198        starting byte set, because \b was not being ignored.
1199    
1200    
1201    Version 8.12 15-Jan-2011
1202    ------------------------
1203    
1204    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1205        checks for such things as part of the documentation building process.
1206    
1207    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1208        --match-limit and --recursion-limit options (added for 8.11). In
1209        particular, this made one of the standard tests fail. (The integer value
1210        went into the wrong half of a long int.)
1211    
1212    3.  If the --colour option was given to pcregrep with -v (invert match), it
1213        did strange things, either producing crazy output, or crashing. It should,
1214        of course, ignore a request for colour when reporting lines that do not
1215        match.
1216    
1217    4.  Another pcregrep bug caused similar problems if --colour was specified with
1218        -M (multiline) and the pattern match finished with a line ending.
1219    
1220    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1221        matched in multiline mode, the following line was shown as part of the
1222        match. This seems wrong, so I have changed it.
1223    
1224    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1225        the check for further matches in the same line (so they could be coloured)
1226        to overrun the end of the current line. If another match was found, it was
1227        incorrectly shown (and then shown again when found in the next line).
1228    
1229    7.  If pcregrep was compiled under Windows, there was a reference to the
1230        function pcregrep_exit() before it was defined. I am assuming this was
1231        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1232        reported by a user. I've moved the definition above the reference.
1233    
1234    
1235    Version 8.11 10-Dec-2010
1236    ------------------------
1237    
1238    1.  (*THEN) was not working properly if there were untried alternatives prior
1239        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1240        backtracked to try for "b" instead of moving to the next alternative branch
1241        at the same level (in this case, to look for "c"). The Perl documentation
1242        is clear that when (*THEN) is backtracked onto, it goes to the "next
1243        alternative in the innermost enclosing group".
1244    
1245    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1246        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1247        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1248        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1249        (*THEN).
1250    
1251    3.  If \s appeared in a character class, it removed the VT character from
1252        the class, even if it had been included by some previous item, for example
1253        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1254        of \s, but is part of the POSIX "space" class.)
1255    
1256    4.  A partial match never returns an empty string (because you can always
1257        match an empty string at the end of the subject); however the checking for
1258        an empty string was starting at the "start of match" point. This has been
1259        changed to the "earliest inspected character" point, because the returned
1260        data for a partial match starts at this character. This means that, for
1261        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1262        (previously it gave "no match").
1263    
1264    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1265        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1266        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1267        has an implication that the given string is incomplete (because a partial
1268        match is preferred over a full match). For this reason, these items now
1269        give a partial match in this situation. [Aside: previously, the one case
1270        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1271        match rather than a full match, which was wrong by the old rules, but is
1272        now correct.]
1273    
1274    6.  There was a bug in the handling of #-introduced comments, recognized when
1275        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1276        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1277        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1278        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1279        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1280        places in pcre_compile().
1281    
1282    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1283        comments when looking ahead for named forward references to subpatterns,
1284        the only newline sequence it recognized was NL. It now handles newlines
1285        according to the set newline convention.
1286    
1287    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1288        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1289        cater for a lack of strerror(). These oversights have been fixed.
1290    
1291    9.  Added --match-limit and --recursion-limit to pcregrep.
1292    
1293    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1294    
1295    11. When the -o option was used, pcregrep was setting a return code of 1, even
1296        when matches were found, and --line-buffered was not being honoured.
1297    
1298    12. Added an optional parentheses number to the -o and --only-matching options
1299        of pcregrep.
1300    
1301    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1302        can match an empty string. The code to do it in pcretest and pcredemo
1303        needed fixing:
1304    
1305        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1306            only one byte after an empty string match just before CRLF (this case
1307            just got forgotten; "any" and "anycrlf" were OK).
1308    
1309        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1310            mode when an empty string match preceded an ASCII character followed by
1311            a non-ASCII character. (The code for advancing by one character rather
1312            than one byte was nonsense.)
1313    
1314        (c) The pcredemo.c sample program did not have any code at all to handle
1315            the cases when CRLF is a valid newline sequence.
1316    
1317    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1318        as a starting offset was within the subject string. There is now a new
1319        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1320        negative or greater than the length of the string. In order to test this,
1321        pcretest is extended to allow the setting of negative starting offsets.
1322    
1323    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1324        starting offset points to the beginning of a UTF-8 character was
1325        unnecessarily clumsy. I tidied it up.
1326    
1327    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1328        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1329    
1330    17. Nobody had reported that the --include_dir option, which was added in
1331        release 7.7 should have been called --include-dir (hyphen, not underscore)
1332        for compatibility with GNU grep. I have changed it to --include-dir, but
1333        left --include_dir as an undocumented synonym, and the same for
1334        --exclude-dir, though that is not available in GNU grep, at least as of
1335        release 2.5.4.
1336    
1337    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1338        characters from a string of bytes) have been redefined so as not to use
1339        loops, in order to improve performance in some environments. At the same
1340        time, I abstracted some of the common code into auxiliary macros to save
1341        repetition (this should not affect the compiled code).
1342    
1343    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1344        compile-time error is now given if \c is not followed by an ASCII
1345        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1346        different, and any byte value is allowed.)
1347    
1348    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1349        START_OPTIMIZE option, which is now allowed at compile time - but just
1350        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1351        to pcregrep and other applications that have no direct access to PCRE
1352        options. The new /Y option in pcretest sets this option when calling
1353        pcre_compile().
1354    
1355    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1356        back references. Groups containing recursive back references were forced to
1357        be atomic by that change, but in the case of named groups, the amount of
1358        memory required was incorrectly computed, leading to "Failed: internal
1359        error: code overflow". This has been fixed.
1360    
1361    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1362        pcretest.c, to avoid build problems in some Borland environments.
1363    
1364    
1365    Version 8.10 25-Jun-2010
1366    ------------------------
1367    
1368    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1369        THEN.
1370    
1371    2.  (*ACCEPT) was not working when inside an atomic group.
1372    
1373    3.  Inside a character class, \B is treated as a literal by default, but
1374        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1375        causes the error). The code is unchanged, but I tidied the documentation.
1376    
1377    4.  Inside a character class, PCRE always treated \R and \X as literals,
1378        whereas Perl faults them if its -w option is set. I have changed PCRE so
1379        that it faults them when PCRE_EXTRA is set.
1380    
1381    5.  Added support for \N, which always matches any character other than
1382        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1383    
1384    6.  When compiling pcregrep with newer versions of gcc which may have
1385        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1386        declared with attribute warn_unused_result" were given. Just casting the
1387        result to (void) does not stop the warnings; a more elaborate fudge is
1388        needed. I've used a macro to implement this.
1389    
1390    7.  Minor change to pcretest.c to avoid a compiler warning.
1391    
1392    8.  Added four artifical Unicode properties to help with an option to make
1393        \s etc use properties (see next item). The new properties are: Xan
1394        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1395    
1396    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1397        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1398        this option. Modified pcretest to add /W to test this facility. Added
1399        REG_UCP to make it available via the POSIX interface.
1400    
1401    10. Added --line-buffered to pcregrep.
1402    
1403    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1404        studied, and the match started with a letter with a code point greater than
1405        127 whose first byte was different to the first byte of the other case of
1406        the letter, the other case of this starting letter was not recognized
1407        (#976).
1408    
1409    12. If a pattern that was studied started with a repeated Unicode property
1410        test, for example, \p{Nd}+, there was the theoretical possibility of
1411        setting up an incorrect bitmap of starting bytes, but fortunately it could
1412        not have actually happened in practice until change 8 above was made (it
1413        added property types that matched character-matching opcodes).
1414    
1415    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1416        possible starting bytes for non-anchored patterns.
1417    
1418    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1419        \R, and also a number of cases that involve Unicode properties, both
1420        explicit and implicit when PCRE_UCP is set.
1421    
1422    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1423        input, it could crash or give wrong results if characters with values
1424        greater than 0xc0 were present in the subject string. (Detail: it assumed
1425        UTF-8 input when processing these items.)
1426    
1427    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1428        size_t is 64-bit (#991).
1429    
1430    17. Added a check for running out of memory when PCRE is compiled with
1431        --disable-stack-for-recursion (#990).
1432    
1433    18. If the last data line in a file for pcretest does not have a newline on
1434        the end, a newline was missing in the output.
1435    
1436    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1437        less than 128) in its various bitmaps. However, there is a facility for
1438        generating tables according to the current locale when PCRE is compiled. It
1439        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1440        characters, are recognized by isspace() and therefore were getting set in
1441        these tables, and indeed these tables seem to approximate to ISO 8859. This
1442        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1443        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1444        which of course cannot start UTF-8 characters. I have changed the code so
1445        that only real ASCII characters (less than 128) and the correct starting
1446        bytes for UTF-8 encodings are set for characters greater than 127 when in
1447        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1448        altogether.)
1449    
1450    20. Added the /T option to pcretest so as to be able to run tests with non-
1451        standard character tables, thus making it possible to include the tests
1452        used for 19 above in the standard set of tests.
1453    
1454    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1455        reference to a subpattern the other side of a comment that contains an
1456        opening parenthesis caused either an internal compiling error, or a
1457        reference to the wrong subpattern.
1458    
1459    
1460    Version 8.02 19-Mar-2010
1461  ------------------------  ------------------------
1462    
1463  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
1464    
1465  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1466      configured.      configured.
1467    
1468  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1469      original author of that file, following a query about its status.      original author of that file, following a query about its status.
1470    
1471  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1472      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1473    
1474  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1475      quantifier applied to a forward-referencing subroutine call, could compile      quantifier applied to a forward-referencing subroutine call, could compile
1476      incorrect code or give the error "internal error: previously-checked      incorrect code or give the error "internal error: previously-checked
1477      referenced subpattern not found".      referenced subpattern not found".
1478    
1479  6.  Both MS Visual Studio and Symbian OS have problems with initializing  6.  Both MS Visual Studio and Symbian OS have problems with initializing
1480      variables to point to external functions. For these systems, therefore,      variables to point to external functions. For these systems, therefore,
1481      pcre_malloc etc. are now initialized to local functions that call the      pcre_malloc etc. are now initialized to local functions that call the
1482      relevant global functions.      relevant global functions.
1483    
1484  7.  There were two entries missing in the vectors called coptable and poptable  7.  There were two entries missing in the vectors called coptable and poptable
1485      in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.      in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1486      I've fixed the data, and added a kludgy way of testing at compile time that      I've fixed the data, and added a kludgy way of testing at compile time that
1487      the lengths are correct (equal to the number of opcodes).      the lengths are correct (equal to the number of opcodes).
1488    
1489  8.  Following on from 7, I added a similar kludge to check the length of the  8.  Following on from 7, I added a similar kludge to check the length of the
1490      eint vector in pcreposix.c.      eint vector in pcreposix.c.
1491    
1492  9.  Error texts for pcre_compile() are held as one long string to avoid too  9.  Error texts for pcre_compile() are held as one long string to avoid too
1493      much relocation at load time. To find a text, the string is searched,      much relocation at load time. To find a text, the string is searched,
1494      counting zeros. There was no check for running off the end of the string,      counting zeros. There was no check for running off the end of the string,
1495      which could happen if a new error number was added without updating the      which could happen if a new error number was added without updating the
1496      string.      string.
1497    
1498  10. \K gave a compile-time error if it appeared in a lookbehind assersion.  10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1499    
1500  11. \K was not working if it appeared in an atomic group or in a group that  11. \K was not working if it appeared in an atomic group or in a group that
1501      was called as a "subroutine", or in an assertion. Perl 5.11 documents that      was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1502      \K is "not well defined" if used in an assertion. PCRE now accepts it if      \K is "not well defined" if used in an assertion. PCRE now accepts it if
1503      the assertion is positive, but not if it is negative.      the assertion is positive, but not if it is negative.
1504    
1505    12. Change 11 fortuitously reduced the size of the stack frame used in the
1506        "match()" function of pcre_exec.c by one pointer. Forthcoming
1507        implementation of support for (*MARK) will need an extra pointer on the
1508        stack; I have reserved it now, so that the stack frame size does not
1509        decrease.
1510    
1511    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1512        item in branch that calls a recursion is a subroutine call - as in the
1513        second branch in the above example - was incorrectly given the compile-
1514        time error "recursive call could loop indefinitely" because pcre_compile()
1515        was not correctly checking the subroutine for matching a non-empty string.
1516    
1517    14. The checks for overrunning compiling workspace could trigger after an
1518        overrun had occurred. This is a "should never occur" error, but it can be
1519        triggered by pathological patterns such as hundreds of nested parentheses.
1520        The checks now trigger 100 bytes before the end of the workspace.
1521    
1522    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1523    
1524    
1525  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
# Line 373  Version 7.9 11-Apr-09 Line 1848  Version 7.9 11-Apr-09
1848  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
1849      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
1850      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1851      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1852        8.33.]
1853    
1854  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
1855      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 616  Version 7.7 07-May-08 Line 2092  Version 7.7 07-May-08
2092      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2093      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2094      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2095      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2096      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2097      was subsequently set up correctly.)      was subsequently set up correctly.)
2098    

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