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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.01 11-Dec-09  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    
174    Version 8.33 28-May-2013
175    ------------------------
176    
177    1.  Added 'U' to some constants that are compared to unsigned integers, to
178        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
179        variables that are added to signed variables, to ensure the result is
180        signed and can be negated.
181    
182    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
183        CMake config files.
184    
185    3.  Revise the creation of config.h.generic so that all boolean macros are
186        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
187        overriding via -D on the command line possible.
188    
189    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
190        to unsigned int is reported to make a quite noticeable speed difference in
191        a specific Windows environment. Testing on Linux did also appear to show
192        some benefit (and it is clearly not harmful). Also fixed the definition of
193        Xop which should be unsigned.
194    
195    5.  Related to (4), changing the definition of the intermediate variable cc
196        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
197        improvements.
198    
199    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
200        unnecessary spaces.
201    
202    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
203        and later.
204    
205    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
206    
207    9.  Optimizing fast_forward_start_bits in JIT.
208    
209    10. Adding support for callouts in JIT, and fixing some issues revealed
210        during this work. Namely:
211    
212        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
213    
214        (b) Minimum length was not checked before the matching is started.
215    
216    11. The value of capture_last that is passed to callouts was incorrect in some
217        cases when there was a capture on one path that was subsequently abandoned
218        after a backtrack. Also, the capture_last value is now reset after a
219        recursion, since all captures are also reset in this case.
220    
221    12. The interpreter no longer returns the "too many substrings" error in the
222        case when an overflowing capture is in a branch that is subsequently
223        abandoned after a backtrack.
224    
225    13. In the pathological case when an offset vector of size 2 is used, pcretest
226        now prints out the matched string after a yield of 0 or 1.
227    
228    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
229        Only supported by the JIT compiler at the moment.
230    
231    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
232    
233    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
234        offset of the starting point of the matching process, provided the offsets
235        vector is large enough.
236    
237    17. The \A escape now records a lookbehind value of 1, though its execution
238        does not actually inspect the previous character. This is to ensure that,
239        in partial multi-segment matching, at least one character from the old
240        segment is retained when a new segment is processed. Otherwise, if there
241        are no lookbehinds in the pattern, \A might match incorrectly at the start
242        of a new segment.
243    
244    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
245    
246    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
247        gives some modest performance improvement in 8-bit mode.
248    
249    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
250        be expressed in certain programming languages using Universal Character
251        Names.
252    
253    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
254        which points out that "non characters" are not "characters that may not
255        appear in Unicode strings" but rather "characters that are reserved for
256        internal use and have only local meaning".
257    
258    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
259        there was a conditional group that depended on an assertion, if the
260        assertion was false, the callout that immediately followed the alternation
261        in the condition was skipped when pcre_exec() was used for matching.
262    
263    23. Allow an explicit callout to be inserted before an assertion that is the
264        condition for a conditional group, for compatibility with automatic
265        callouts, which always insert a callout at this point.
266    
267    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
268        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
269    
270    25. (*PRUNE) is now supported by the JIT compiler.
271    
272    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
273    
274    27. Fix the case where there are two or more SKIPs with arguments that may be
275        ignored.
276    
277    28. (*SKIP) is now supported by the JIT compiler.
278    
279    29. (*THEN) is now supported by the JIT compiler.
280    
281    30. Update RunTest with additional test selector options.
282    
283    31. The way PCRE handles backtracking verbs has been changed in two ways.
284    
285        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
286        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
287        backtracking. In some cases this makes it more Perl-compatible, but Perl's
288        rather obscure rules do not always do the same thing.
289    
290        (2) Previously, backtracking verbs were confined within assertions. This is
291        no longer the case for positive assertions, except for (*ACCEPT). Again,
292        this sometimes improves Perl compatibility, and sometimes does not.
293    
294    32. A number of tests that were in test 2 because Perl did things differently
295        have been moved to test 1, because either Perl or PCRE has changed, and
296        these tests are now compatible.
297    
298    32. Backtracking control verbs are now handled in the same way in JIT and
299        interpreter.
300    
301    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
302        contained a forward subroutine reference caused a compile error.
303    
304    34. Auto-detect and optimize limited repetitions in JIT.
305    
306    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
307        blocking (*UTF) etc.
308    
309    36. In the interpreter, maximizing pattern repetitions for characters and
310        character types now use tail recursion, which reduces stack usage.
311    
312    37. The value of the max lookbehind was not correctly preserved if a compiled
313        and saved regex was reloaded on a host of different endianness.
314    
315    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
316        of the compiled pattern block, expand the flags field from 16 to 32 bits
317        because it was almost full.
318    
319    39. Try madvise first before posix_madvise.
320    
321    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
322        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
323        original change locked out all matches of empty strings. This has been
324        changed so that one match of an empty string per line is recognized.
325        Subsequent searches on the same line (for colouring or for --only-matching,
326        for example) do not recognize empty strings.
327    
328    41. Applied a user patch to fix a number of spelling mistakes in comments.
329    
330    42. Data lines longer than 65536 caused pcretest to crash.
331    
332    43. Clarified the data type for length and startoffset arguments for pcre_exec
333        and pcre_dfa_exec in the function-specific man pages, where they were
334        explicitly stated to be in bytes, never having been updated. I also added
335        some clarification to the pcreapi man page.
336    
337    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
338        a segmentation fault.
339    
340    
341    Version 8.32 30-November-2012
342    -----------------------------
343    
344    1.  Improved JIT compiler optimizations for first character search and single
345        character iterators.
346    
347    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
348        Patch by Daniel Richard G.
349    
350    3.  Single character iterator optimizations in the JIT compiler.
351    
352    4.  Improved JIT compiler optimizations for character ranges.
353    
354    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
355        Reported by Giuseppe D'Angelo.
356    
357    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
358        of a line, was being set incorrectly in cases where .* appeared inside
359        atomic brackets at the start of a pattern, or where there was a subsequent
360        *PRUNE or *SKIP.
361    
362    7.  Improved instruction cache flush for POWER/PowerPC.
363        Patch by Daniel Richard G.
364    
365    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
366        grep:
367    
368        (a) There is now no limit to the number of patterns to be matched.
369    
370        (b) An error is given if a pattern is too long.
371    
372        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
373            are now supported.
374    
375        (d) --exclude-from and --include-from (multiple use) have been added.
376    
377        (e) Exclusions and inclusions now apply to all files and directories, not
378            just to those obtained from scanning a directory recursively.
379    
380        (f) Multiple uses of -f and --file-list are now supported.
381    
382        (g) In a Windows environment, the default for -d has been changed from
383            "read" (the GNU grep default) to "skip", because otherwise the presence
384            of a directory in the file list provokes an error.
385    
386        (h) The documentation has been revised and clarified in places.
387    
388    9.  Improve the matching speed of capturing brackets.
389    
390    10. Changed the meaning of \X so that it now matches a Unicode extended
391        grapheme cluster.
392    
393    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
394        out POSIX threads when JIT support is configured.
395    
396    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
397    
398    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
399        structure could go wrong in environments where size_t is not the same size
400        as int.
401    
402    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
403        set.
404    
405    15. The EBCDIC support had decayed; later updates to the code had included
406        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
407        general tidy up of EBCDIC-related issues, and the documentation was also
408        not quite right. There is now a test that can be run on ASCII systems to
409        check some of the EBCDIC-related things (but is it not a full test).
410    
411    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
412        in a small tidy to the code.
413    
414    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
415    
416    18. If the --only-matching (-o) option in pcregrep is specified multiple
417        times, each one causes appropriate output. For example, -o1 -o2 outputs the
418        substrings matched by the 1st and 2nd capturing parentheses. A separating
419        string can be specified by --om-separator (default empty).
420    
421    19. Improving the first n character searches.
422    
423    20. Turn case lists for horizontal and vertical white space into macros so that
424        they are defined only once.
425    
426    21. This set of changes together give more compatible Unicode case-folding
427        behaviour for characters that have more than one other case when UCP
428        support is available.
429    
430        (a) The Unicode property table now has offsets into a new table of sets of
431            three or more characters that are case-equivalent. The MultiStage2.py
432            script that generates these tables (the pcre_ucd.c file) now scans
433            CaseFolding.txt instead of UnicodeData.txt for character case
434            information.
435    
436        (b) The code for adding characters or ranges of characters to a character
437            class has been abstracted into a generalized function that also handles
438            case-independence. In UTF-mode with UCP support, this uses the new data
439            to handle characters with more than one other case.
440    
441        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
442            whose other case is greater than 256 are now correctly matched
443            caselessly. Previously, the high codepoint matched the low one, but not
444            vice versa.
445    
446        (d) The processing of \h, \H, \v, and \ in character classes now makes use
447            of the new class addition function, using character lists defined as
448            macros alongside the case definitions of 20 above.
449    
450        (e) Caseless back references now work with characters that have more than
451            one other case.
452    
453        (f) General caseless matching of characters with more than one other case
454            is supported.
455    
456    22. Unicode character properties were updated from Unicode 6.2.0
457    
458    23. Improved CMake support under Windows. Patch by Daniel Richard G.
459    
460    24. Add support for 32-bit character strings, and UTF-32
461    
462    25. Major JIT compiler update (code refactoring and bugfixing).
463        Experimental Sparc 32 support is added.
464    
465    26. Applied a modified version of Daniel Richard G's patch to create
466        pcre.h.generic and config.h.generic by "make" instead of in the
467        PrepareRelease script.
468    
469    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
470        pcre_compile.c when checking for a zero character.
471    
472    28. Introducing a native interface for JIT. Through this interface, the compiled
473        machine code can be directly executed. The purpose of this interface is to
474        provide fast pattern matching, so several sanity checks are not performed.
475        However, feature tests are still performed. The new interface provides
476        1.4x speedup compared to the old one.
477    
478    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
479        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
480        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
481    
482    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
483        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
484        the "old" RFC 2279). Instead, it ended up passing a negative length to
485        pcre_exec().
486    
487    31. Add support for GCC's visibility feature to hide internal functions.
488    
489    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
490        "unknown -C option" after outputting 0 or 1.
491    
492    33. There is now support for generating a code coverage report for the test
493        suite in environments where gcc is the compiler and lcov is installed. This
494        is mainly for the benefit of the developers.
495    
496    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
497        unaddressable using valgrind annotations, allowing valgrind to detect
498        invalid memory accesses. This is mainly for the benefit of the developers.
499    
500    25. (*UTF) can now be used to start a pattern in any of the three libraries.
501    
502    26. Give configure error if --enable-cpp but no C++ compiler found.
503    
504    
505    Version 8.31 06-July-2012
506    -------------------------
507    
508    1.  Fixing a wrong JIT test case and some compiler warnings.
509    
510    2.  Removed a bashism from the RunTest script.
511    
512    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
513        to unsigned type, result still unsigned" that was given by an MS compiler
514        on encountering the code "-sizeof(xxx)".
515    
516    4.  Partial matching support is added to the JIT compiler.
517    
518    5.  Fixed several bugs concerned with partial matching of items that consist
519        of more than one character:
520    
521        (a) /^(..)\1/ did not partially match "aba" because checking references was
522            done on an "all or nothing" basis. This also applied to repeated
523            references.
524    
525        (b) \R did not give a hard partial match if \r was found at the end of the
526            subject.
527    
528        (c) \X did not give a hard partial match after matching one or more
529            characters at the end of the subject.
530    
531        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
532            a partial match for the string "\r".
533    
534        (e) When newline was set to CRLF, the metacharacter "." did not recognize
535            a partial match for a CR character at the end of the subject string.
536    
537    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
538        running pcretest, the text "(JIT)" added to the output whenever JIT is
539        actually used to run the match.
540    
541    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
542        or /S+[+] with a digit between 1 and 7.
543    
544    8.  OP_NOT now supports any UTF character not just single-byte ones.
545    
546    9.  (*MARK) control verb is now supported by the JIT compiler.
547    
548    10. The command "./RunTest list" lists the available tests without actually
549        running any of them. (Because I keep forgetting what they all are.)
550    
551    11. Add PCRE_INFO_MAXLOOKBEHIND.
552    
553    12. Applied a (slightly modified) user-supplied patch that improves performance
554        when the heap is used for recursion (compiled with --disable-stack-for-
555        recursion). Instead of malloc and free for each heap frame each time a
556        logical recursion happens, frames are retained on a chain and re-used where
557        possible. This sometimes gives as much as 30% improvement.
558    
559    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
560        call.
561    
562    14. As documented, (*COMMIT) is now confined to within a positive assertion.
563    
564    15. It is now possible to link pcretest with libedit as an alternative to
565        libreadline.
566    
567    16. (*COMMIT) control verb is now supported by the JIT compiler.
568    
569    17. The Unicode data tables have been updated to Unicode 6.1.0.
570    
571    18. Added --file-list option to pcregrep.
572    
573    19. Added binary file support to pcregrep, including the -a, --binary-files,
574        -I, and --text options.
575    
576    20. The madvise function is renamed for posix_madvise for QNX compatibility
577        reasons. Fixed by Giuseppe D'Angelo.
578    
579    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
580    
581    22. Changed the option for creating symbolic links for 16-bit man pages from
582        -s to -sf so that re-installing does not cause issues.
583    
584    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
585    
586    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
587        matches in certain environments (the workspace was not being correctly
588        retained). Also added to pcre_dfa_exec() a simple plausibility check on
589        some of the workspace data at the beginning of a restart.
590    
591    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
592        was not doing so when it should - probably a typo introduced by SVN 528
593        (change 8.10/14).
594    
595    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
596        \w+ when the character tables indicated that \x{c4} was a word character.
597        There were several related cases, all because the tests for doing a table
598        lookup were testing for characters less than 127 instead of 255.
599    
600    27. If a pattern contains capturing parentheses that are not used in a match,
601        their slots in the ovector are set to -1. For those that are higher than
602        any matched groups, this happens at the end of processing. In the case when
603        there were back references that the ovector was too small to contain
604        (causing temporary malloc'd memory to be used during matching), and the
605        highest capturing number was not used, memory off the end of the ovector
606        was incorrectly being set to -1. (It was using the size of the temporary
607        memory instead of the true size.)
608    
609    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
610        ovector size, it uses memory at the end of the block that it has got.
611    
612    29. Check for an overlong MARK name and give an error at compile time. The
613        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
614    
615    30. JIT compiler update.
616    
617    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
618        Rill for the patch.
619    
620    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
621    
622    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
623    
624    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
625        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
626        was enabled.
627    
628    35. Improve JIT code generation for greedy plus quantifier.
629    
630    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
631        1 to "aa" instead of to an empty string. The bug affected repeated groups
632        that could potentially match an empty string.
633    
634    37. Optimizing single character iterators in JIT.
635    
636    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
637        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
638        codepoints that are too big for the mode are faulted, and in a UTF mode,
639        disallowed codepoints are also faulted.
640    
641    39. If PCRE was compiled with UTF support, in three places in the DFA
642        matcher there was code that should only have been obeyed in UTF mode, but
643        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
644        processing when bytes with values greater than 127 were present. In 16-bit
645        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
646        both cases the values are those that cannot be the first data item in a UTF
647        character. The three items that might have provoked this were recursions,
648        possessively repeated groups, and atomic groups.
649    
650    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
651        and pcregrep, because some OS require shared objects to be explicitly
652        passed to ld, causing the link step to fail if they are not.
653    
654    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
655        mode, patterns that started with \h* or \R* might be incorrectly matched.
656    
657    
658    Version 8.30 04-February-2012
659    -----------------------------
660    
661    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
662        name is defined in ctype.h.
663    
664    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
665        only in quite long subpatterns.
666    
667    3.  Removed the function pcre_info(), which has been obsolete and deprecated
668        since it was replaced by pcre_fullinfo() in February 2000.
669    
670    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
671        match a (*MARK), and the match failed at the start of the subject, a
672        reference to memory before the start of the subject could occur. This bug
673        was introduced by fix 17 of release 8.21.
674    
675    5.  A reference to an unset group with zero minimum repetition was giving
676        totally wrong answers (in non-JavaScript-compatibility mode). For example,
677        /(another)?(\1?)test/ matched against "hello world test". This bug was
678        introduced in release 8.13.
679    
680    6.  Add support for 16-bit character strings (a large amount of work involving
681        many changes and refactorings).
682    
683    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
684        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
685        from a file.
686    
687    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
688        rounding is not applied in this particular case).
689    
690    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
691        if they appear, or are escaped, in patterns.
692    
693    10. Get rid of a number of -Wunused-but-set-variable warnings.
694    
695    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
696        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
697        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
698        also returns the mark "x". This bug applied to capturing parentheses,
699        non-capturing parentheses, and atomic parentheses. It also applied to some
700        assertions.
701    
702    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
703        information out of configure.ac instead of relying on pcre.h.generic, which
704        is not stored in the repository.
705    
706    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
707        -lreadline.
708    
709    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
710    
711    15. Applied Graycode's patch to put the top-level frame on the stack rather
712        than the heap when not using the stack for recursion. This gives a
713        performance improvement in many cases when recursion is not deep.
714    
715    16. Experimental code added to "pcretest -C" to output the stack frame size.
716    
717    
718    Version 8.21 12-Dec-2011
719    ------------------------
720    
721    1.  Updating the JIT compiler.
722    
723    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
724        are added as well.
725    
726    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
727        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
728        calling _pcre_jit_exec. Some extra comments are added.
729    
730    4.  (*MARK) settings inside atomic groups that do not contain any capturing
731        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
732        was introduced by change 18 for 8.20.
733    
734    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
735        ECMA-262 standard.
736    
737    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
738        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
739        This bug was probably introduced by change 9 of 8.13.
740    
741    7.  While fixing 6 above, I noticed that a number of other items were being
742        incorrectly rejected as "not fixed length". This arose partly because newer
743        opcodes had not been added to the fixed-length checking code. I have (a)
744        corrected the bug and added tests for these items, and (b) arranged for an
745        error to occur if an unknown opcode is encountered while checking for fixed
746        length instead of just assuming "not fixed length". The items that were
747        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
748        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
749        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
750    
751    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
752        being incorrectly compiled and would have given unpredicatble results.
753    
754    9.  A possessively repeated subpattern with minimum repeat count greater than
755        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
756        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
757        the first (A) could occur when it should not.
758    
759    10. Add a cast and remove a redundant test from the code.
760    
761    11. JIT should use pcre_malloc/pcre_free for allocation.
762    
763    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
764        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
765        is anything other than /usr, -L is still shown).
766    
767    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
768    
769    14. Perl does not support \N without a following name in a [] class; PCRE now
770        also gives an error.
771    
772    15. If a forward reference was repeated with an upper limit of around 2000,
773        it caused the error "internal error: overran compiling workspace". The
774        maximum number of forward references (including repeats) was limited by the
775        internal workspace, and dependent on the LINK_SIZE. The code has been
776        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
777        the default depends on LINK_SIZE. There is a new upper limit (for safety)
778        of around 200,000 forward references. While doing this, I also speeded up
779        the filling in of repeated forward references.
780    
781    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
782        incorrectly expecting the subject to contain another "a" after the start.
783    
784    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
785        in the match, the SKIP should be ignored. This was not happening; instead
786        the SKIP was being treated as NOMATCH. For patterns such as
787        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
788        tested.
789    
790    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
791        now much more compatible with Perl, in particular in cases where the result
792        is a non-match for a non-anchored pattern. For example, if
793        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
794        "m", where previously it did not return a name. A side effect of this
795        change is that for partial matches, the last encountered mark name is
796        returned, as for non matches. A number of tests that were previously not
797        Perl-compatible have been moved into the Perl-compatible test files. The
798        refactoring has had the pleasing side effect of removing one argument from
799        the match() function, thus reducing its stack requirements.
800    
801    19. If the /S+ option was used in pcretest to study a pattern using JIT,
802        subsequent uses of /S (without +) incorrectly behaved like /S+.
803    
804    21. Retrieve executable code size support for the JIT compiler and fixing
805        some warnings.
806    
807    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
808        not work when the shorter character appeared right at the end of the
809        subject string.
810    
811    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
812        systems.
813    
814    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
815        output it when the /M option is used in pcretest.
816    
817    25. The CheckMan script was not being included in the distribution. Also, added
818        an explicit "perl" to run Perl scripts from the PrepareRelease script
819        because this is reportedly needed in Windows.
820    
821    26. If study data was being save in a file and studying had not found a set of
822        "starts with" bytes for the pattern, the data written to the file (though
823        never used) was taken from uninitialized memory and so caused valgrind to
824        complain.
825    
826    27. Updated RunTest.bat as provided by Sheri Pierce.
827    
828    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
829    
830    29. Computation of memory usage for the table of capturing group names was
831        giving an unnecessarily large value.
832    
833    
834    Version 8.20 21-Oct-2011
835    ------------------------
836    
837    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
838        a POSIX class. After further experiments with Perl, which convinced me that
839        Perl has bugs and confusions, a closing square bracket is no longer allowed
840        in a POSIX name. This bug also affected patterns with classes that started
841        with full stops.
842    
843    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
844        captured substring, but while checking the failing first alternative,
845        substring 1 is temporarily captured. If the output vector supplied to
846        pcre_exec() was not big enough for this capture, the yield of the function
847        was still zero ("insufficient space for captured substrings"). This cannot
848        be totally fixed without adding another stack variable, which seems a lot
849        of expense for a edge case. However, I have improved the situation in cases
850        such as /(a)(b)x|abc/ matched against "abc", where the return code
851        indicates that fewer than the maximum number of slots in the ovector have
852        been set.
853    
854    3.  Related to (2) above: when there are more back references in a pattern than
855        slots in the output vector, pcre_exec() uses temporary memory during
856        matching, and copies in the captures as far as possible afterwards. It was
857        using the entire output vector, but this conflicts with the specification
858        that only 2/3 is used for passing back captured substrings. Now it uses
859        only the first 2/3, for compatibility. This is, of course, another edge
860        case.
861    
862    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
863        main code base, and can be used by building with --enable-jit. When this is
864        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
865        runtime --no-jit option is given.
866    
867    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
868        ovector, the return from the function was zero, implying that there were
869        other matches that did not fit. The correct "exactly full" value is now
870        returned.
871    
872    6.  If a subpattern that was called recursively or as a subroutine contained
873        (*PRUNE) or any other control that caused it to give a non-standard return,
874        invalid errors such as "Error -26 (nested recursion at the same subject
875        position)" or even infinite loops could occur.
876    
877    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
878        computing the minimum length on reaching *ACCEPT, and so ended up with the
879        wrong value of 1 rather than 0. Further investigation indicates that
880        computing a minimum subject length in the presence of *ACCEPT is difficult
881        (think back references, subroutine calls), and so I have changed the code
882        so that no minimum is registered for a pattern that contains *ACCEPT.
883    
884    8.  If (*THEN) was present in the first (true) branch of a conditional group,
885        it was not handled as intended. [But see 16 below.]
886    
887    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
888        Sheri Pierce.
889    
890    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
891        the first byte in a match must be "a".
892    
893    11. Change 17 for 8.13 increased the recursion depth for patterns like
894        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
895        pattern contains any instances of (*THEN). If it does not, the old
896        optimizations are restored. It would be nice to do this on a per-group
897        basis, but at the moment that is not feasible.
898    
899    12. In some environments, the output of pcretest -C is CRLF terminated. This
900        broke RunTest's code that checks for the link size. A single white space
901        character after the value is now allowed for.
902    
903    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
904        For "fr", it uses the Windows-specific input and output files.
905    
906    14. If (*THEN) appeared in a group that was called recursively or as a
907        subroutine, it did not work as intended. [But see next item.]
908    
909    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
910        pattern fragments (but not containing any | characters). If A and B are
911        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
912        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
913        D. In other words, Perl considers parentheses that do not contain any |
914        characters to be part of a surrounding alternative, whereas PCRE was
915        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
916        differently. PCRE now behaves in the same way as Perl, except in the case
917        of subroutine/recursion calls such as (?1) which have in any case always
918        been different (but PCRE had them first :-).
919    
920    16. Related to 15 above: Perl does not treat the | in a conditional group as
921        creating alternatives. Such a group is treated in the same way as an
922        ordinary group without any | characters when processing (*THEN). PCRE has
923        been changed to match Perl's behaviour.
924    
925    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
926        RunGrepTest script failed.
927    
928    18. Change 22 for version 13 caused atomic groups to use more stack. This is
929        inevitable for groups that contain captures, but it can lead to a lot of
930        stack use in large patterns. The old behaviour has been restored for atomic
931        groups that do not contain any capturing parentheses.
932    
933    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
934        suppress the check for a minimum subject length at run time. (If it was
935        given to pcre_exec() or pcre_dfa_exec() it did work.)
936    
937    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
938        fail to work when decoding hex characters in data strings in EBCDIC
939        environments.
940    
941    21. It appears that in at least one Mac OS environment, the isxdigit() function
942        is implemented as a macro that evaluates to its argument more than once,
943        contravening the C 90 Standard (I haven't checked a later standard). There
944        was an instance in pcretest which caused it to go wrong when processing
945        \x{...} escapes in subject strings. The has been rewritten to avoid using
946        things like p++ in the argument of isxdigit().
947    
948    
949    Version 8.13 16-Aug-2011
950    ------------------------
951    
952    1.  The Unicode data tables have been updated to Unicode 6.0.0.
953    
954    2.  Two minor typos in pcre_internal.h have been fixed.
955    
956    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
957        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
958        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
959    
960    4.  There were a number of related bugs in the code for matching backrefences
961        caselessly in UTF-8 mode when codes for the characters concerned were
962        different numbers of bytes. For example, U+023A and U+2C65 are an upper
963        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
964        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
965        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
966        2-byte code at the end of the subject (it thought there wasn't enough data
967        left).
968    
969    5.  Comprehensive information about what went wrong is now returned by
970        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
971        as the output vector has at least 2 elements. The offset of the start of
972        the failing character and a reason code are placed in the vector.
973    
974    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
975        now returned is for the first byte of the failing character, instead of the
976        last byte inspected. This is an incompatible change, but I hope it is small
977        enough not to be a problem. It makes the returned offset consistent with
978        pcre_exec() and pcre_dfa_exec().
979    
980    7.  pcretest now gives a text phrase as well as the error number when
981        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
982        failure, the offset and reason code are output.
983    
984    8.  When \R was used with a maximizing quantifier it failed to skip backwards
985        over a \r\n pair if the subsequent match failed. Instead, it just skipped
986        back over a single character (\n). This seems wrong (because it treated the
987        two characters as a single entity when going forwards), conflicts with the
988        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
989        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
990        has been changed.
991    
992    9.  Some internal refactoring has changed the processing so that the handling
993        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
994        time (the PCRE_DOTALL option was changed this way some time ago: version
995        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
996        which was always a bit of a fudge. It also means that there is one less
997        argument for the match() function, which reduces its stack requirements
998        slightly. This change also fixes an incompatibility with Perl: the pattern
999        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1000    
1001    10. More internal refactoring has drastically reduced the number of recursive
1002        calls to match() for possessively repeated groups such as (abc)++ when
1003        using pcre_exec().
1004    
1005    11. While implementing 10, a number of bugs in the handling of groups were
1006        discovered and fixed:
1007    
1008        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1009        (a|)*(?1) gave a compile-time internal error.
1010        ((a|)+)+  did not notice that the outer group could match an empty string.
1011        (^a|^)+   was not marked as anchored.
1012        (.*a|.*)+ was not marked as matching at start or after a newline.
1013    
1014    12. Yet more internal refactoring has removed another argument from the match()
1015        function. Special calls to this function are now indicated by setting a
1016        value in a variable in the "match data" data block.
1017    
1018    13. Be more explicit in pcre_study() instead of relying on "default" for
1019        opcodes that mean there is no starting character; this means that when new
1020        ones are added and accidentally left out of pcre_study(), testing should
1021        pick them up.
1022    
1023    14. The -s option of pcretest has been documented for ages as being an old
1024        synonym of -m (show memory usage). I have changed it to mean "force study
1025        for every regex", that is, assume /S for every regex. This is similar to -i
1026        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1027        using it. It makes it easier to run collections of tests with and without
1028        study enabled, and thereby test pcre_study() more easily. All the standard
1029        tests are now run with and without -s (but some patterns can be marked as
1030        "never study" - see 20 below).
1031    
1032    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1033        restoration of the capturing data to the outer values was not happening
1034        correctly.
1035    
1036    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1037        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1038        pattern had matched an empty string, and so incorrectly returned a no
1039        match.
1040    
1041    17. There was optimizing code for the last branch of non-capturing parentheses,
1042        and also for the obeyed branch of a conditional subexpression, which used
1043        tail recursion to cut down on stack usage. Unfortunately, now that there is
1044        the possibility of (*THEN) occurring in these branches, tail recursion is
1045        no longer possible because the return has to be checked for (*THEN). These
1046        two optimizations have therefore been removed. [But see 8.20/11 above.]
1047    
1048    18. If a pattern containing \R was studied, it was assumed that \R always
1049        matched two bytes, thus causing the minimum subject length to be
1050        incorrectly computed because \R can also match just one byte.
1051    
1052    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1053        was incorrectly computed.
1054    
1055    20. If /S is present twice on a test pattern in pcretest input, it now
1056        *disables* studying, thereby overriding the use of -s on the command line
1057        (see 14 above). This is necessary for one or two tests to keep the output
1058        identical in both cases.
1059    
1060    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1061        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1062    
1063    22. When an atomic group that contained a capturing parenthesis was
1064        successfully matched, but the branch in which it appeared failed, the
1065        capturing was not being forgotten if a higher numbered group was later
1066        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1067        group 1 to "a", when in fact it should be unset. This applied to multi-
1068        branched capturing and non-capturing groups, repeated or not, and also to
1069        positive assertions (capturing in negative assertions does not happen
1070        in PCRE) and also to nested atomic groups.
1071    
1072    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1073        subject after a captured substring, to make it easier to tell which of a
1074        number of identical substrings has been captured.
1075    
1076    24. The way atomic groups are processed by pcre_exec() has been changed so that
1077        if they are repeated, backtracking one repetition now resets captured
1078        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1079        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1080        "aaa". Previously, it would have been "a". As part of this code
1081        refactoring, the way recursive calls are handled has also been changed.
1082    
1083    25. If an assertion condition captured any substrings, they were not passed
1084        back unless some other capturing happened later. For example, if
1085        (?(?=(a))a) was matched against "a", no capturing was returned.
1086    
1087    26. When studying a pattern that contained subroutine calls or assertions,
1088        the code for finding the minimum length of a possible match was handling
1089        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1090        group 1 called group 2 while simultaneously a separate group 2 called group
1091        1). A stack overflow occurred in this case. I have fixed this by limiting
1092        the recursion depth to 10.
1093    
1094    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1095        Fortmann. This supports explicit test numbers on the command line, and has
1096        argument validation and error reporting.
1097    
1098    28. An instance of \X with an unlimited repeat could fail if at any point the
1099        first character it looked at was a mark character.
1100    
1101    29. Some minor code refactoring concerning Unicode properties and scripts
1102        should reduce the stack requirement of match() slightly.
1103    
1104    30. Added the '=' option to pcretest to check the setting of unused capturing
1105        slots at the end of the pattern, which are documented as being -1, but are
1106        not included in the return count.
1107    
1108    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1109        compiled something random. Now it gives a compile-time error (as does
1110        Perl).
1111    
1112    32. A *MARK encountered during the processing of a positive assertion is now
1113        recorded and passed back (compatible with Perl).
1114    
1115    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1116        had alternative anchored branches, the search for a second match in a line
1117        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1118        matched the line "0102" twice. The same bug affected patterns that started
1119        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1120        twice.
1121    
1122    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1123        does, and because of capturing effects, quantifying parenthesized
1124        assertions may at times be useful. Quantifiers are now allowed for
1125        parenthesized assertions.
1126    
1127    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1128    
1129    36. \g was being checked for fancy things in a character class, when it should
1130        just be a literal "g".
1131    
1132    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1133        appearance of a nested POSIX class supersedes an apparent external class.
1134        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1135        unescaped square brackets may also appear as part of class names. For
1136        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1137        more like Perl. (But see 8.20/1 above.)
1138    
1139    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1140        was because it thought it was \N{name}, which is not supported).
1141    
1142    39. Add minix to OS list not supporting the -S option in pcretest.
1143    
1144    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1145        cannot analyze patterns in sufficient detail to catch mutual recursions
1146        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1147        subgroup is called recursively as a subpattern for a second time at the
1148        same position in the subject string. In previous releases this might have
1149        been caught by the recursion limit, or it might have run out of stack.
1150    
1151    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1152        happen only once. PCRE was, however incorrectly giving a compile time error
1153        "recursive call could loop indefinitely" because it cannot analyze the
1154        pattern in sufficient detail. The compile time test no longer happens when
1155        PCRE is compiling a conditional subpattern, but actual runaway loops are
1156        now caught at runtime (see 40 above).
1157    
1158    42. It seems that Perl allows any characters other than a closing parenthesis
1159        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1160        has been changed to be the same.
1161    
1162    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1163        as not to get warnings when autogen.sh is called. Also changed
1164        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1165    
1166    44. To help people who use pcregrep to scan files containing exceedingly long
1167        lines, the following changes have been made:
1168    
1169        (a) The default value of the buffer size parameter has been increased from
1170            8K to 20K. (The actual buffer used is three times this size.)
1171    
1172        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1173            PCRE is built.
1174    
1175        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1176            to be set at run time.
1177    
1178        (d) Numerical values in pcregrep options can be followed by K or M, for
1179            example --buffer-size=50K.
1180    
1181        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1182            given and the return code is set to 2.
1183    
1184    45. Add a pointer to the latest mark to the callout data block.
1185    
1186    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1187        partial match of an empty string instead of no match. This was specific to
1188        the use of ".".
1189    
1190    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1191        complete match instead of a partial match. This bug was dependent on both
1192        the PCRE_UTF8 and PCRE_DOTALL options being set.
1193    
1194    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1195        starting byte set, because \b was not being ignored.
1196    
1197    
1198    Version 8.12 15-Jan-2011
1199    ------------------------
1200    
1201    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1202        checks for such things as part of the documentation building process.
1203    
1204    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1205        --match-limit and --recursion-limit options (added for 8.11). In
1206        particular, this made one of the standard tests fail. (The integer value
1207        went into the wrong half of a long int.)
1208    
1209    3.  If the --colour option was given to pcregrep with -v (invert match), it
1210        did strange things, either producing crazy output, or crashing. It should,
1211        of course, ignore a request for colour when reporting lines that do not
1212        match.
1213    
1214    4.  Another pcregrep bug caused similar problems if --colour was specified with
1215        -M (multiline) and the pattern match finished with a line ending.
1216    
1217    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1218        matched in multiline mode, the following line was shown as part of the
1219        match. This seems wrong, so I have changed it.
1220    
1221    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1222        the check for further matches in the same line (so they could be coloured)
1223        to overrun the end of the current line. If another match was found, it was
1224        incorrectly shown (and then shown again when found in the next line).
1225    
1226    7.  If pcregrep was compiled under Windows, there was a reference to the
1227        function pcregrep_exit() before it was defined. I am assuming this was
1228        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1229        reported by a user. I've moved the definition above the reference.
1230    
1231    
1232    Version 8.11 10-Dec-2010
1233    ------------------------
1234    
1235    1.  (*THEN) was not working properly if there were untried alternatives prior
1236        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1237        backtracked to try for "b" instead of moving to the next alternative branch
1238        at the same level (in this case, to look for "c"). The Perl documentation
1239        is clear that when (*THEN) is backtracked onto, it goes to the "next
1240        alternative in the innermost enclosing group".
1241    
1242    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1243        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1244        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1245        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1246        (*THEN).
1247    
1248    3.  If \s appeared in a character class, it removed the VT character from
1249        the class, even if it had been included by some previous item, for example
1250        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1251        of \s, but is part of the POSIX "space" class.)
1252    
1253    4.  A partial match never returns an empty string (because you can always
1254        match an empty string at the end of the subject); however the checking for
1255        an empty string was starting at the "start of match" point. This has been
1256        changed to the "earliest inspected character" point, because the returned
1257        data for a partial match starts at this character. This means that, for
1258        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1259        (previously it gave "no match").
1260    
1261    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1262        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1263        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1264        has an implication that the given string is incomplete (because a partial
1265        match is preferred over a full match). For this reason, these items now
1266        give a partial match in this situation. [Aside: previously, the one case
1267        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1268        match rather than a full match, which was wrong by the old rules, but is
1269        now correct.]
1270    
1271    6.  There was a bug in the handling of #-introduced comments, recognized when
1272        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1273        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1274        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1275        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1276        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1277        places in pcre_compile().
1278    
1279    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1280        comments when looking ahead for named forward references to subpatterns,
1281        the only newline sequence it recognized was NL. It now handles newlines
1282        according to the set newline convention.
1283    
1284    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1285        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1286        cater for a lack of strerror(). These oversights have been fixed.
1287    
1288    9.  Added --match-limit and --recursion-limit to pcregrep.
1289    
1290    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1291    
1292    11. When the -o option was used, pcregrep was setting a return code of 1, even
1293        when matches were found, and --line-buffered was not being honoured.
1294    
1295    12. Added an optional parentheses number to the -o and --only-matching options
1296        of pcregrep.
1297    
1298    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1299        can match an empty string. The code to do it in pcretest and pcredemo
1300        needed fixing:
1301    
1302        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1303            only one byte after an empty string match just before CRLF (this case
1304            just got forgotten; "any" and "anycrlf" were OK).
1305    
1306        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1307            mode when an empty string match preceded an ASCII character followed by
1308            a non-ASCII character. (The code for advancing by one character rather
1309            than one byte was nonsense.)
1310    
1311        (c) The pcredemo.c sample program did not have any code at all to handle
1312            the cases when CRLF is a valid newline sequence.
1313    
1314    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1315        as a starting offset was within the subject string. There is now a new
1316        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1317        negative or greater than the length of the string. In order to test this,
1318        pcretest is extended to allow the setting of negative starting offsets.
1319    
1320    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1321        starting offset points to the beginning of a UTF-8 character was
1322        unnecessarily clumsy. I tidied it up.
1323    
1324    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1325        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1326    
1327    17. Nobody had reported that the --include_dir option, which was added in
1328        release 7.7 should have been called --include-dir (hyphen, not underscore)
1329        for compatibility with GNU grep. I have changed it to --include-dir, but
1330        left --include_dir as an undocumented synonym, and the same for
1331        --exclude-dir, though that is not available in GNU grep, at least as of
1332        release 2.5.4.
1333    
1334    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1335        characters from a string of bytes) have been redefined so as not to use
1336        loops, in order to improve performance in some environments. At the same
1337        time, I abstracted some of the common code into auxiliary macros to save
1338        repetition (this should not affect the compiled code).
1339    
1340    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1341        compile-time error is now given if \c is not followed by an ASCII
1342        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1343        different, and any byte value is allowed.)
1344    
1345    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1346        START_OPTIMIZE option, which is now allowed at compile time - but just
1347        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1348        to pcregrep and other applications that have no direct access to PCRE
1349        options. The new /Y option in pcretest sets this option when calling
1350        pcre_compile().
1351    
1352    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1353        back references. Groups containing recursive back references were forced to
1354        be atomic by that change, but in the case of named groups, the amount of
1355        memory required was incorrectly computed, leading to "Failed: internal
1356        error: code overflow". This has been fixed.
1357    
1358    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1359        pcretest.c, to avoid build problems in some Borland environments.
1360    
1361    
1362    Version 8.10 25-Jun-2010
1363    ------------------------
1364    
1365    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1366        THEN.
1367    
1368    2.  (*ACCEPT) was not working when inside an atomic group.
1369    
1370    3.  Inside a character class, \B is treated as a literal by default, but
1371        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1372        causes the error). The code is unchanged, but I tidied the documentation.
1373    
1374    4.  Inside a character class, PCRE always treated \R and \X as literals,
1375        whereas Perl faults them if its -w option is set. I have changed PCRE so
1376        that it faults them when PCRE_EXTRA is set.
1377    
1378    5.  Added support for \N, which always matches any character other than
1379        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1380    
1381    6.  When compiling pcregrep with newer versions of gcc which may have
1382        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1383        declared with attribute warn_unused_result" were given. Just casting the
1384        result to (void) does not stop the warnings; a more elaborate fudge is
1385        needed. I've used a macro to implement this.
1386    
1387    7.  Minor change to pcretest.c to avoid a compiler warning.
1388    
1389    8.  Added four artifical Unicode properties to help with an option to make
1390        \s etc use properties (see next item). The new properties are: Xan
1391        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1392    
1393    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1394        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1395        this option. Modified pcretest to add /W to test this facility. Added
1396        REG_UCP to make it available via the POSIX interface.
1397    
1398    10. Added --line-buffered to pcregrep.
1399    
1400    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1401        studied, and the match started with a letter with a code point greater than
1402        127 whose first byte was different to the first byte of the other case of
1403        the letter, the other case of this starting letter was not recognized
1404        (#976).
1405    
1406    12. If a pattern that was studied started with a repeated Unicode property
1407        test, for example, \p{Nd}+, there was the theoretical possibility of
1408        setting up an incorrect bitmap of starting bytes, but fortunately it could
1409        not have actually happened in practice until change 8 above was made (it
1410        added property types that matched character-matching opcodes).
1411    
1412    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1413        possible starting bytes for non-anchored patterns.
1414    
1415    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1416        \R, and also a number of cases that involve Unicode properties, both
1417        explicit and implicit when PCRE_UCP is set.
1418    
1419    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1420        input, it could crash or give wrong results if characters with values
1421        greater than 0xc0 were present in the subject string. (Detail: it assumed
1422        UTF-8 input when processing these items.)
1423    
1424    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1425        size_t is 64-bit (#991).
1426    
1427    17. Added a check for running out of memory when PCRE is compiled with
1428        --disable-stack-for-recursion (#990).
1429    
1430    18. If the last data line in a file for pcretest does not have a newline on
1431        the end, a newline was missing in the output.
1432    
1433    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1434        less than 128) in its various bitmaps. However, there is a facility for
1435        generating tables according to the current locale when PCRE is compiled. It
1436        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1437        characters, are recognized by isspace() and therefore were getting set in
1438        these tables, and indeed these tables seem to approximate to ISO 8859. This
1439        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1440        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1441        which of course cannot start UTF-8 characters. I have changed the code so
1442        that only real ASCII characters (less than 128) and the correct starting
1443        bytes for UTF-8 encodings are set for characters greater than 127 when in
1444        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1445        altogether.)
1446    
1447    20. Added the /T option to pcretest so as to be able to run tests with non-
1448        standard character tables, thus making it possible to include the tests
1449        used for 19 above in the standard set of tests.
1450    
1451    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1452        reference to a subpattern the other side of a comment that contains an
1453        opening parenthesis caused either an internal compiling error, or a
1454        reference to the wrong subpattern.
1455    
1456    
1457    Version 8.02 19-Mar-2010
1458    ------------------------
1459    
1460    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1461    
1462    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1463        configured.
1464    
1465    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1466        original author of that file, following a query about its status.
1467    
1468    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1469        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1470    
1471    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1472        quantifier applied to a forward-referencing subroutine call, could compile
1473        incorrect code or give the error "internal error: previously-checked
1474        referenced subpattern not found".
1475    
1476    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1477        variables to point to external functions. For these systems, therefore,
1478        pcre_malloc etc. are now initialized to local functions that call the
1479        relevant global functions.
1480    
1481    7.  There were two entries missing in the vectors called coptable and poptable
1482        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1483        I've fixed the data, and added a kludgy way of testing at compile time that
1484        the lengths are correct (equal to the number of opcodes).
1485    
1486    8.  Following on from 7, I added a similar kludge to check the length of the
1487        eint vector in pcreposix.c.
1488    
1489    9.  Error texts for pcre_compile() are held as one long string to avoid too
1490        much relocation at load time. To find a text, the string is searched,
1491        counting zeros. There was no check for running off the end of the string,
1492        which could happen if a new error number was added without updating the
1493        string.
1494    
1495    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1496    
1497    11. \K was not working if it appeared in an atomic group or in a group that
1498        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1499        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1500        the assertion is positive, but not if it is negative.
1501    
1502    12. Change 11 fortuitously reduced the size of the stack frame used in the
1503        "match()" function of pcre_exec.c by one pointer. Forthcoming
1504        implementation of support for (*MARK) will need an extra pointer on the
1505        stack; I have reserved it now, so that the stack frame size does not
1506        decrease.
1507    
1508    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1509        item in branch that calls a recursion is a subroutine call - as in the
1510        second branch in the above example - was incorrectly given the compile-
1511        time error "recursive call could loop indefinitely" because pcre_compile()
1512        was not correctly checking the subroutine for matching a non-empty string.
1513    
1514    14. The checks for overrunning compiling workspace could trigger after an
1515        overrun had occurred. This is a "should never occur" error, but it can be
1516        triggered by pathological patterns such as hundreds of nested parentheses.
1517        The checks now trigger 100 bytes before the end of the workspace.
1518    
1519    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1520    
1521    
1522    Version 8.01 19-Jan-2010
1523    ------------------------
1524    
1525  1.  If a pattern contained a conditional subpattern with only one branch (in  1.  If a pattern contained a conditional subpattern with only one branch (in
1526      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1527      computed the wrong minimum data length (which is of course zero for such      computed the wrong minimum data length (which is of course zero for such
1528      subpatterns).      subpatterns). This could cause incorrect "no match" results.
1529    
1530  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1531      the pattern is reset in the first branch, pcre_compile() failed with      the pattern is reset in the first branch, pcre_compile() failed with
# Line 61  Version 8.01 11-Dec-09 Line 1579  Version 8.01 11-Dec-09
1579      custom one, because of the following reported problem in Windows:      custom one, because of the following reported problem in Windows:
1580    
1581        - libbz2 uses the Pascal calling convention (WINAPI) for the functions        - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1582          under Win32.            under Win32.
1583        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1584          therefore missing the function definition.            therefore missing the function definition.
1585        - The compiler thus generates a "C" signature for the test function.        - The compiler thus generates a "C" signature for the test function.
1586        - The linker fails to find the "C" function.        - The linker fails to find the "C" function.
1587        - PCRE fails to configure if asked to do so against libbz2.        - PCRE fails to configure if asked to do so against libbz2.
1588    
1589  11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these  11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1590      messages were output:      messages were output:
1591    
1592        Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and        Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1593        rerunning libtoolize, to keep the correct libtool macros in-tree.        rerunning libtoolize, to keep the correct libtool macros in-tree.
1594        Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.        Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1595    
1596      I have done both of these things.      I have done both of these things.
1597    
1598  12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()  12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1599      most of the time, it *can* run out if it is given a pattern that contains a      most of the time, it *can* run out if it is given a pattern that contains a
1600      runaway infinite recursion. I updated the discussion in the pcrestack man      runaway infinite recursion. I updated the discussion in the pcrestack man
1601      page.      page.
1602    
1603  13. Now that we have gone to the x.xx style of version numbers, the minor  13. Now that we have gone to the x.xx style of version numbers, the minor
1604      version may start with zero. Using 08 or 09 is a bad idea because users      version may start with zero. Using 08 or 09 is a bad idea because users
1605      might check the value of PCRE_MINOR in their code, and 08 or 09 may be      might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1606      interpreted as invalid octal numbers. I've updated the previous comment in      interpreted as invalid octal numbers. I've updated the previous comment in
1607      configure.ac, and also added a check that gives an error if 08 or 09 are      configure.ac, and also added a check that gives an error if 08 or 09 are
1608      used.      used.
1609    
1610  14. Change 8.00/11 was not quite complete: code had been accidentally omitted,  14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1611      causing partial matching to fail when the end of the subject matched \W      causing partial matching to fail when the end of the subject matched \W
1612      in a UTF-8 pattern where \W was quantified with a minimum of 3.      in a UTF-8 pattern where \W was quantified with a minimum of 3.
1613    
1614  15. There were some discrepancies between the declarations in pcre_internal.h  15. There were some discrepancies between the declarations in pcre_internal.h
1615      of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and      of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1616      their definitions. The declarations used "const uschar *" and the      their definitions. The declarations used "const uschar *" and the
1617      definitions used USPTR. Even though USPTR is normally defined as "const      definitions used USPTR. Even though USPTR is normally defined as "const
1618      unsigned char *" (and uschar is typedeffed as "unsigned char"), it was      unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1619      reported that: "This difference in casting confuses some C++ compilers, for      reported that: "This difference in casting confuses some C++ compilers, for
1620      example, SunCC recognizes above declarations as different functions and      example, SunCC recognizes above declarations as different functions and
1621      generates broken code for hbpcre." I have changed the declarations to use      generates broken code for hbpcre." I have changed the declarations to use
1622      USPTR.      USPTR.
1623    
1624    16. GNU libtool is named differently on some systems. The autogen.sh script now
1625        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1626        (FreeBSD).
1627    
1628    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1629        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1630        comment: "Figure out how to create a longlong from a string: strtoll and
1631        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1632        instance, but it only takes 2 args instead of 3!"
1633    
1634    18. A subtle bug concerned with back references has been fixed by a change of
1635        specification, with a corresponding code fix. A pattern such as
1636        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1637        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1638        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1639        same bug. Such groups have to be quantified to be useful, or contained
1640        inside another quantified group. (If there's no repetition, the reference
1641        can never match.) The problem arises because, having left the group and
1642        moved on to the rest of the pattern, a later failure that backtracks into
1643        the group uses the captured value from the final iteration of the group
1644        rather than the correct earlier one. I have fixed this in PCRE by forcing
1645        any group that contains a reference to itself to be an atomic group; that
1646        is, there cannot be any backtracking into it once it has completed. This is
1647        similar to recursive and subroutine calls.
1648    
1649    
1650  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09
# Line 304  Version 7.9 11-Apr-09 Line 1845  Version 7.9 11-Apr-09
1845  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
1846      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
1847      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1848      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1849        8.33.]
1850    
1851  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
1852      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 547  Version 7.7 07-May-08 Line 2089  Version 7.7 07-May-08
2089      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2090      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2091      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2092      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2093      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2094      was subsequently set up correctly.)      was subsequently set up correctly.)
2095    

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