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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 30-Apr-2011  Version 8.34 xx-xxxx-201x
5    --------------------------
6    
7    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8        executable memory. Patch inspired by Carsten Klein.
9    
10    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
11        this macro is never tested and has no effect, because the work to support
12        coverage involves only compiling and linking options and special targets in
13        the Makefile. The comment in config.h implied that defining the macro would
14        enable coverage support, which is totally false. There was also support for
15        setting this macro in the CMake files (my fault, I just copied it from
16        configure). SUPPORT_GCOV has now been removed.
17    
18    3.  Make a small performance improvement in strlen16() and strlen32() in
19        pcretest.
20    
21    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
22        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
23        these cases). There was also one in pcretest.c.
24    
25    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
26    
27    6.  In UTF mode, the code for checking whether a group could match an empty
28        string (which is used for indefinitely repeated groups to allow for
29        breaking an infinite loop) was broken when the group contained a repeated
30        negated single-character class with a character that occupied more than one
31        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
32        UTF-8 mode). The effect was undefined: the group might or might not be
33        deemed as matching an empty string, or the program might have crashed.
34    
35    7.  The code for checking whether a group could match an empty string was not
36        recognizing that \h, \H, \v, \V, and \R must match a character.
37    
38    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
39        an empty string. If it can, pcretest shows this in its information output.
40    
41    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
42        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
43        matched by pcre_exec() without using JIT:
44    
45        (a) If the rest of the pattern did not match after a maximal run of
46            grapheme clusters, the code for backing up to try with fewer of them
47            did not always back up over a full grapheme when characters that do not
48            have the modifier quality were involved, e.g. Hangul syllables.
49    
50        (b) If the match point in a subject started with modifier character, and
51            there was no match, the code could incorrectly back up beyond the match
52            point, and potentially beyond the first character in the subject,
53            leading to a segfault or an incorrect match result.
54    
55    10. A conditional group with an assertion condition could lead to PCRE
56        recording an incorrect first data item for a match if no other first data
57        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
58        first data item, and therefore matched "ca" after "c" instead of at the
59        start.
60    
61    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
62        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
63    
64    12. The source of pcregrep now includes z/OS-specific code so that it can be
65        compiled for z/OS as part of the special z/OS distribution.
66    
67    13. Added the -T and -TM options to pcretest.
68    
69    14. The code in pcre_compile.c for creating the table of named capturing groups
70        has been refactored. Instead of creating the table dynamically during the
71        actual compiling pass, the information is remembered during the pre-compile
72        pass (on the stack unless there are more than 20 named groups, in which
73        case malloc() is used) and the whole table is created before the actual
74        compile happens. This has simplified the code (it is now nearly 150 lines
75        shorter) and prepared the way for better handling of references to groups
76        with duplicate names.
77    
78    15. A back reference to a named subpattern when there is more than one of the
79        same name now checks them in the order in which they appear in the pattern.
80        The first one that is set is used for the reference. Previously only the
81        first one was inspected. This change makes PCRE more compatible with Perl.
82    
83    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. It can also be set by
90        (*NO_AUTO_POSSESS) at the start of a pattern.
91    
92    18. The character VT has been added to the set of characters that match \s and
93        are generally treated as white space, following this same change in Perl
94        5.18. There is now no difference between "Perl space" and "POSIX space".
95    
96    19. The code for checking named groups as conditions, either for being set or
97        for being recursed, has been refactored (this is related to 14 and 15
98        above). Processing unduplicated named groups should now be as fast at
99        numerical groups, and processing duplicated groups should be faster than
100        before.
101    
102    20. Two patches to the CMake build system, by Alexander Barkov:
103    
104          (1) Replace the "source" command by "." in CMakeLists.txt because
105              "source" is a bash-ism.
106    
107          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
108              without these the CMake build does not work on Solaris.
109    
110    21. Perl has changed its handling of \8 and \9. If there is no previously
111        encountered capturing group of those numbers, they are treated as the
112        literal characters 8 and 9 instead of a binary zero followed by the
113        literals. PCRE now does the same.
114    
115    22. Following Perl, added \o{} to specify codepoints in octal, making it
116        possible to specify values greater than 0777 and also making them
117        unambiguous.
118    
119    23. Perl now gives an error for missing closing braces after \x{... instead of
120        treating the string as literal. PCRE now does the same.
121    
122    24. RunTest used to grumble if an inappropriate test was selected explicitly,
123        but just skip it when running all tests. This make it awkward to run ranges
124        of tests when one of them was inappropriate. Now it just skips any
125        inappropriate tests, as it always did when running all tests.
126    
127    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
128        character types such as \d or \w, too many callouts were inserted, and the
129        data that they returned was rubbish.
130    
131    26. In UCP mode, \s was not matching two of the characters that Perl matches,
132        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
133        were matched by \h. The code has now been refactored so that the lists of
134        the horizontal and vertical whitespace characters used for \h and \v (which
135        are defined only in one place) are now also used for \s.
136    
137    27. Add JIT support for the 64 bit TileGX architecture.
138        Patch by Jiong Wang (Tilera Corporation).
139    
140    28. Possessive quantifiers for classes (both explicit and automatically
141        generated) now use special opcodes instead of wrapping in ONCE brackets.
142    
143    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
144        (because it's meaningless), this was not happening when PCRE_CASELESS was
145        set. Not wrong, but inefficient.
146    
147    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
148        properties for \w, \d, etc) is present in a test regex. Otherwise if the
149        test contains no characters greater than 255, Perl doesn't realise it
150        should be using Unicode semantics.
151    
152    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
153        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
154        does in Unicode mode.
155    
156    32. Added the "forbid" facility to pcretest so that putting tests into the
157        wrong test files can sometimes be quickly detected.
158    
159    33. There is now a limit (default 250) on the depth of nesting of parentheses.
160        This limit is imposed to control the amount of system stack used at compile
161        time. It can be changed at build time by --with-parens-nest-limit=xxx or
162        the equivalent in CMake.
163    
164    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
165        errors. Perl warns for these when in warning mode, but PCRE has no facility
166        for giving warnings.
167    
168    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
169        However, this was not working for (?!) because it is optimized to (*FAIL),
170        for which PCRE does not allow quantifiers. The optimization is now disabled
171        when a quantifier follows (?!). I can't see any use for this, but it makes
172        things uniform.
173    
174    36. Perl no longer allows group names to start with digits, so I have made this
175        change also in PCRE. It simplifies the code a bit.
176    
177    
178    Version 8.33 28-May-2013
179    ------------------------
180    
181    1.  Added 'U' to some constants that are compared to unsigned integers, to
182        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
183        variables that are added to signed variables, to ensure the result is
184        signed and can be negated.
185    
186    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
187        CMake config files.
188    
189    3.  Revise the creation of config.h.generic so that all boolean macros are
190        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
191        overriding via -D on the command line possible.
192    
193    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
194        to unsigned int is reported to make a quite noticeable speed difference in
195        a specific Windows environment. Testing on Linux did also appear to show
196        some benefit (and it is clearly not harmful). Also fixed the definition of
197        Xop which should be unsigned.
198    
199    5.  Related to (4), changing the definition of the intermediate variable cc
200        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
201        improvements.
202    
203    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
204        unnecessary spaces.
205    
206    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
207        and later.
208    
209    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
210    
211    9.  Optimizing fast_forward_start_bits in JIT.
212    
213    10. Adding support for callouts in JIT, and fixing some issues revealed
214        during this work. Namely:
215    
216        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
217    
218        (b) Minimum length was not checked before the matching is started.
219    
220    11. The value of capture_last that is passed to callouts was incorrect in some
221        cases when there was a capture on one path that was subsequently abandoned
222        after a backtrack. Also, the capture_last value is now reset after a
223        recursion, since all captures are also reset in this case.
224    
225    12. The interpreter no longer returns the "too many substrings" error in the
226        case when an overflowing capture is in a branch that is subsequently
227        abandoned after a backtrack.
228    
229    13. In the pathological case when an offset vector of size 2 is used, pcretest
230        now prints out the matched string after a yield of 0 or 1.
231    
232    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
233        Only supported by the JIT compiler at the moment.
234    
235    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
236    
237    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
238        offset of the starting point of the matching process, provided the offsets
239        vector is large enough.
240    
241    17. The \A escape now records a lookbehind value of 1, though its execution
242        does not actually inspect the previous character. This is to ensure that,
243        in partial multi-segment matching, at least one character from the old
244        segment is retained when a new segment is processed. Otherwise, if there
245        are no lookbehinds in the pattern, \A might match incorrectly at the start
246        of a new segment.
247    
248    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
249    
250    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
251        gives some modest performance improvement in 8-bit mode.
252    
253    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
254        be expressed in certain programming languages using Universal Character
255        Names.
256    
257    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
258        which points out that "non characters" are not "characters that may not
259        appear in Unicode strings" but rather "characters that are reserved for
260        internal use and have only local meaning".
261    
262    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
263        there was a conditional group that depended on an assertion, if the
264        assertion was false, the callout that immediately followed the alternation
265        in the condition was skipped when pcre_exec() was used for matching.
266    
267    23. Allow an explicit callout to be inserted before an assertion that is the
268        condition for a conditional group, for compatibility with automatic
269        callouts, which always insert a callout at this point.
270    
271    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
272        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
273    
274    25. (*PRUNE) is now supported by the JIT compiler.
275    
276    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
277    
278    27. Fix the case where there are two or more SKIPs with arguments that may be
279        ignored.
280    
281    28. (*SKIP) is now supported by the JIT compiler.
282    
283    29. (*THEN) is now supported by the JIT compiler.
284    
285    30. Update RunTest with additional test selector options.
286    
287    31. The way PCRE handles backtracking verbs has been changed in two ways.
288    
289        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
290        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
291        backtracking. In some cases this makes it more Perl-compatible, but Perl's
292        rather obscure rules do not always do the same thing.
293    
294        (2) Previously, backtracking verbs were confined within assertions. This is
295        no longer the case for positive assertions, except for (*ACCEPT). Again,
296        this sometimes improves Perl compatibility, and sometimes does not.
297    
298    32. A number of tests that were in test 2 because Perl did things differently
299        have been moved to test 1, because either Perl or PCRE has changed, and
300        these tests are now compatible.
301    
302    32. Backtracking control verbs are now handled in the same way in JIT and
303        interpreter.
304    
305    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
306        contained a forward subroutine reference caused a compile error.
307    
308    34. Auto-detect and optimize limited repetitions in JIT.
309    
310    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
311        blocking (*UTF) etc.
312    
313    36. In the interpreter, maximizing pattern repetitions for characters and
314        character types now use tail recursion, which reduces stack usage.
315    
316    37. The value of the max lookbehind was not correctly preserved if a compiled
317        and saved regex was reloaded on a host of different endianness.
318    
319    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
320        of the compiled pattern block, expand the flags field from 16 to 32 bits
321        because it was almost full.
322    
323    39. Try madvise first before posix_madvise.
324    
325    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
326        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
327        original change locked out all matches of empty strings. This has been
328        changed so that one match of an empty string per line is recognized.
329        Subsequent searches on the same line (for colouring or for --only-matching,
330        for example) do not recognize empty strings.
331    
332    41. Applied a user patch to fix a number of spelling mistakes in comments.
333    
334    42. Data lines longer than 65536 caused pcretest to crash.
335    
336    43. Clarified the data type for length and startoffset arguments for pcre_exec
337        and pcre_dfa_exec in the function-specific man pages, where they were
338        explicitly stated to be in bytes, never having been updated. I also added
339        some clarification to the pcreapi man page.
340    
341    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
342        a segmentation fault.
343    
344    
345    Version 8.32 30-November-2012
346    -----------------------------
347    
348    1.  Improved JIT compiler optimizations for first character search and single
349        character iterators.
350    
351    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
352        Patch by Daniel Richard G.
353    
354    3.  Single character iterator optimizations in the JIT compiler.
355    
356    4.  Improved JIT compiler optimizations for character ranges.
357    
358    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
359        Reported by Giuseppe D'Angelo.
360    
361    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
362        of a line, was being set incorrectly in cases where .* appeared inside
363        atomic brackets at the start of a pattern, or where there was a subsequent
364        *PRUNE or *SKIP.
365    
366    7.  Improved instruction cache flush for POWER/PowerPC.
367        Patch by Daniel Richard G.
368    
369    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
370        grep:
371    
372        (a) There is now no limit to the number of patterns to be matched.
373    
374        (b) An error is given if a pattern is too long.
375    
376        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
377            are now supported.
378    
379        (d) --exclude-from and --include-from (multiple use) have been added.
380    
381        (e) Exclusions and inclusions now apply to all files and directories, not
382            just to those obtained from scanning a directory recursively.
383    
384        (f) Multiple uses of -f and --file-list are now supported.
385    
386        (g) In a Windows environment, the default for -d has been changed from
387            "read" (the GNU grep default) to "skip", because otherwise the presence
388            of a directory in the file list provokes an error.
389    
390        (h) The documentation has been revised and clarified in places.
391    
392    9.  Improve the matching speed of capturing brackets.
393    
394    10. Changed the meaning of \X so that it now matches a Unicode extended
395        grapheme cluster.
396    
397    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
398        out POSIX threads when JIT support is configured.
399    
400    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
401    
402    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
403        structure could go wrong in environments where size_t is not the same size
404        as int.
405    
406    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
407        set.
408    
409    15. The EBCDIC support had decayed; later updates to the code had included
410        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
411        general tidy up of EBCDIC-related issues, and the documentation was also
412        not quite right. There is now a test that can be run on ASCII systems to
413        check some of the EBCDIC-related things (but is it not a full test).
414    
415    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
416        in a small tidy to the code.
417    
418    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
419    
420    18. If the --only-matching (-o) option in pcregrep is specified multiple
421        times, each one causes appropriate output. For example, -o1 -o2 outputs the
422        substrings matched by the 1st and 2nd capturing parentheses. A separating
423        string can be specified by --om-separator (default empty).
424    
425    19. Improving the first n character searches.
426    
427    20. Turn case lists for horizontal and vertical white space into macros so that
428        they are defined only once.
429    
430    21. This set of changes together give more compatible Unicode case-folding
431        behaviour for characters that have more than one other case when UCP
432        support is available.
433    
434        (a) The Unicode property table now has offsets into a new table of sets of
435            three or more characters that are case-equivalent. The MultiStage2.py
436            script that generates these tables (the pcre_ucd.c file) now scans
437            CaseFolding.txt instead of UnicodeData.txt for character case
438            information.
439    
440        (b) The code for adding characters or ranges of characters to a character
441            class has been abstracted into a generalized function that also handles
442            case-independence. In UTF-mode with UCP support, this uses the new data
443            to handle characters with more than one other case.
444    
445        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
446            whose other case is greater than 256 are now correctly matched
447            caselessly. Previously, the high codepoint matched the low one, but not
448            vice versa.
449    
450        (d) The processing of \h, \H, \v, and \ in character classes now makes use
451            of the new class addition function, using character lists defined as
452            macros alongside the case definitions of 20 above.
453    
454        (e) Caseless back references now work with characters that have more than
455            one other case.
456    
457        (f) General caseless matching of characters with more than one other case
458            is supported.
459    
460    22. Unicode character properties were updated from Unicode 6.2.0
461    
462    23. Improved CMake support under Windows. Patch by Daniel Richard G.
463    
464    24. Add support for 32-bit character strings, and UTF-32
465    
466    25. Major JIT compiler update (code refactoring and bugfixing).
467        Experimental Sparc 32 support is added.
468    
469    26. Applied a modified version of Daniel Richard G's patch to create
470        pcre.h.generic and config.h.generic by "make" instead of in the
471        PrepareRelease script.
472    
473    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
474        pcre_compile.c when checking for a zero character.
475    
476    28. Introducing a native interface for JIT. Through this interface, the compiled
477        machine code can be directly executed. The purpose of this interface is to
478        provide fast pattern matching, so several sanity checks are not performed.
479        However, feature tests are still performed. The new interface provides
480        1.4x speedup compared to the old one.
481    
482    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
483        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
484        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
485    
486    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
487        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
488        the "old" RFC 2279). Instead, it ended up passing a negative length to
489        pcre_exec().
490    
491    31. Add support for GCC's visibility feature to hide internal functions.
492    
493    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
494        "unknown -C option" after outputting 0 or 1.
495    
496    33. There is now support for generating a code coverage report for the test
497        suite in environments where gcc is the compiler and lcov is installed. This
498        is mainly for the benefit of the developers.
499    
500    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
501        unaddressable using valgrind annotations, allowing valgrind to detect
502        invalid memory accesses. This is mainly for the benefit of the developers.
503    
504    25. (*UTF) can now be used to start a pattern in any of the three libraries.
505    
506    26. Give configure error if --enable-cpp but no C++ compiler found.
507    
508    
509    Version 8.31 06-July-2012
510    -------------------------
511    
512    1.  Fixing a wrong JIT test case and some compiler warnings.
513    
514    2.  Removed a bashism from the RunTest script.
515    
516    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
517        to unsigned type, result still unsigned" that was given by an MS compiler
518        on encountering the code "-sizeof(xxx)".
519    
520    4.  Partial matching support is added to the JIT compiler.
521    
522    5.  Fixed several bugs concerned with partial matching of items that consist
523        of more than one character:
524    
525        (a) /^(..)\1/ did not partially match "aba" because checking references was
526            done on an "all or nothing" basis. This also applied to repeated
527            references.
528    
529        (b) \R did not give a hard partial match if \r was found at the end of the
530            subject.
531    
532        (c) \X did not give a hard partial match after matching one or more
533            characters at the end of the subject.
534    
535        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
536            a partial match for the string "\r".
537    
538        (e) When newline was set to CRLF, the metacharacter "." did not recognize
539            a partial match for a CR character at the end of the subject string.
540    
541    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
542        running pcretest, the text "(JIT)" added to the output whenever JIT is
543        actually used to run the match.
544    
545    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
546        or /S+[+] with a digit between 1 and 7.
547    
548    8.  OP_NOT now supports any UTF character not just single-byte ones.
549    
550    9.  (*MARK) control verb is now supported by the JIT compiler.
551    
552    10. The command "./RunTest list" lists the available tests without actually
553        running any of them. (Because I keep forgetting what they all are.)
554    
555    11. Add PCRE_INFO_MAXLOOKBEHIND.
556    
557    12. Applied a (slightly modified) user-supplied patch that improves performance
558        when the heap is used for recursion (compiled with --disable-stack-for-
559        recursion). Instead of malloc and free for each heap frame each time a
560        logical recursion happens, frames are retained on a chain and re-used where
561        possible. This sometimes gives as much as 30% improvement.
562    
563    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
564        call.
565    
566    14. As documented, (*COMMIT) is now confined to within a positive assertion.
567    
568    15. It is now possible to link pcretest with libedit as an alternative to
569        libreadline.
570    
571    16. (*COMMIT) control verb is now supported by the JIT compiler.
572    
573    17. The Unicode data tables have been updated to Unicode 6.1.0.
574    
575    18. Added --file-list option to pcregrep.
576    
577    19. Added binary file support to pcregrep, including the -a, --binary-files,
578        -I, and --text options.
579    
580    20. The madvise function is renamed for posix_madvise for QNX compatibility
581        reasons. Fixed by Giuseppe D'Angelo.
582    
583    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
584    
585    22. Changed the option for creating symbolic links for 16-bit man pages from
586        -s to -sf so that re-installing does not cause issues.
587    
588    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
589    
590    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
591        matches in certain environments (the workspace was not being correctly
592        retained). Also added to pcre_dfa_exec() a simple plausibility check on
593        some of the workspace data at the beginning of a restart.
594    
595    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
596        was not doing so when it should - probably a typo introduced by SVN 528
597        (change 8.10/14).
598    
599    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
600        \w+ when the character tables indicated that \x{c4} was a word character.
601        There were several related cases, all because the tests for doing a table
602        lookup were testing for characters less than 127 instead of 255.
603    
604    27. If a pattern contains capturing parentheses that are not used in a match,
605        their slots in the ovector are set to -1. For those that are higher than
606        any matched groups, this happens at the end of processing. In the case when
607        there were back references that the ovector was too small to contain
608        (causing temporary malloc'd memory to be used during matching), and the
609        highest capturing number was not used, memory off the end of the ovector
610        was incorrectly being set to -1. (It was using the size of the temporary
611        memory instead of the true size.)
612    
613    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
614        ovector size, it uses memory at the end of the block that it has got.
615    
616    29. Check for an overlong MARK name and give an error at compile time. The
617        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
618    
619    30. JIT compiler update.
620    
621    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
622        Rill for the patch.
623    
624    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
625    
626    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
627    
628    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
629        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
630        was enabled.
631    
632    35. Improve JIT code generation for greedy plus quantifier.
633    
634    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
635        1 to "aa" instead of to an empty string. The bug affected repeated groups
636        that could potentially match an empty string.
637    
638    37. Optimizing single character iterators in JIT.
639    
640    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
641        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
642        codepoints that are too big for the mode are faulted, and in a UTF mode,
643        disallowed codepoints are also faulted.
644    
645    39. If PCRE was compiled with UTF support, in three places in the DFA
646        matcher there was code that should only have been obeyed in UTF mode, but
647        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
648        processing when bytes with values greater than 127 were present. In 16-bit
649        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
650        both cases the values are those that cannot be the first data item in a UTF
651        character. The three items that might have provoked this were recursions,
652        possessively repeated groups, and atomic groups.
653    
654    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
655        and pcregrep, because some OS require shared objects to be explicitly
656        passed to ld, causing the link step to fail if they are not.
657    
658    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
659        mode, patterns that started with \h* or \R* might be incorrectly matched.
660    
661    
662    Version 8.30 04-February-2012
663    -----------------------------
664    
665    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
666        name is defined in ctype.h.
667    
668    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
669        only in quite long subpatterns.
670    
671    3.  Removed the function pcre_info(), which has been obsolete and deprecated
672        since it was replaced by pcre_fullinfo() in February 2000.
673    
674    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
675        match a (*MARK), and the match failed at the start of the subject, a
676        reference to memory before the start of the subject could occur. This bug
677        was introduced by fix 17 of release 8.21.
678    
679    5.  A reference to an unset group with zero minimum repetition was giving
680        totally wrong answers (in non-JavaScript-compatibility mode). For example,
681        /(another)?(\1?)test/ matched against "hello world test". This bug was
682        introduced in release 8.13.
683    
684    6.  Add support for 16-bit character strings (a large amount of work involving
685        many changes and refactorings).
686    
687    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
688        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
689        from a file.
690    
691    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
692        rounding is not applied in this particular case).
693    
694    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
695        if they appear, or are escaped, in patterns.
696    
697    10. Get rid of a number of -Wunused-but-set-variable warnings.
698    
699    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
700        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
701        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
702        also returns the mark "x". This bug applied to capturing parentheses,
703        non-capturing parentheses, and atomic parentheses. It also applied to some
704        assertions.
705    
706    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
707        information out of configure.ac instead of relying on pcre.h.generic, which
708        is not stored in the repository.
709    
710    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
711        -lreadline.
712    
713    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
714    
715    15. Applied Graycode's patch to put the top-level frame on the stack rather
716        than the heap when not using the stack for recursion. This gives a
717        performance improvement in many cases when recursion is not deep.
718    
719    16. Experimental code added to "pcretest -C" to output the stack frame size.
720    
721    
722    Version 8.21 12-Dec-2011
723    ------------------------
724    
725    1.  Updating the JIT compiler.
726    
727    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
728        are added as well.
729    
730    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
731        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
732        calling _pcre_jit_exec. Some extra comments are added.
733    
734    4.  (*MARK) settings inside atomic groups that do not contain any capturing
735        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
736        was introduced by change 18 for 8.20.
737    
738    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
739        ECMA-262 standard.
740    
741    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
742        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
743        This bug was probably introduced by change 9 of 8.13.
744    
745    7.  While fixing 6 above, I noticed that a number of other items were being
746        incorrectly rejected as "not fixed length". This arose partly because newer
747        opcodes had not been added to the fixed-length checking code. I have (a)
748        corrected the bug and added tests for these items, and (b) arranged for an
749        error to occur if an unknown opcode is encountered while checking for fixed
750        length instead of just assuming "not fixed length". The items that were
751        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
752        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
753        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
754    
755    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
756        being incorrectly compiled and would have given unpredicatble results.
757    
758    9.  A possessively repeated subpattern with minimum repeat count greater than
759        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
760        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
761        the first (A) could occur when it should not.
762    
763    10. Add a cast and remove a redundant test from the code.
764    
765    11. JIT should use pcre_malloc/pcre_free for allocation.
766    
767    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
768        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
769        is anything other than /usr, -L is still shown).
770    
771    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
772    
773    14. Perl does not support \N without a following name in a [] class; PCRE now
774        also gives an error.
775    
776    15. If a forward reference was repeated with an upper limit of around 2000,
777        it caused the error "internal error: overran compiling workspace". The
778        maximum number of forward references (including repeats) was limited by the
779        internal workspace, and dependent on the LINK_SIZE. The code has been
780        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
781        the default depends on LINK_SIZE. There is a new upper limit (for safety)
782        of around 200,000 forward references. While doing this, I also speeded up
783        the filling in of repeated forward references.
784    
785    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
786        incorrectly expecting the subject to contain another "a" after the start.
787    
788    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
789        in the match, the SKIP should be ignored. This was not happening; instead
790        the SKIP was being treated as NOMATCH. For patterns such as
791        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
792        tested.
793    
794    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
795        now much more compatible with Perl, in particular in cases where the result
796        is a non-match for a non-anchored pattern. For example, if
797        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
798        "m", where previously it did not return a name. A side effect of this
799        change is that for partial matches, the last encountered mark name is
800        returned, as for non matches. A number of tests that were previously not
801        Perl-compatible have been moved into the Perl-compatible test files. The
802        refactoring has had the pleasing side effect of removing one argument from
803        the match() function, thus reducing its stack requirements.
804    
805    19. If the /S+ option was used in pcretest to study a pattern using JIT,
806        subsequent uses of /S (without +) incorrectly behaved like /S+.
807    
808    21. Retrieve executable code size support for the JIT compiler and fixing
809        some warnings.
810    
811    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
812        not work when the shorter character appeared right at the end of the
813        subject string.
814    
815    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
816        systems.
817    
818    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
819        output it when the /M option is used in pcretest.
820    
821    25. The CheckMan script was not being included in the distribution. Also, added
822        an explicit "perl" to run Perl scripts from the PrepareRelease script
823        because this is reportedly needed in Windows.
824    
825    26. If study data was being save in a file and studying had not found a set of
826        "starts with" bytes for the pattern, the data written to the file (though
827        never used) was taken from uninitialized memory and so caused valgrind to
828        complain.
829    
830    27. Updated RunTest.bat as provided by Sheri Pierce.
831    
832    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
833    
834    29. Computation of memory usage for the table of capturing group names was
835        giving an unnecessarily large value.
836    
837    
838    Version 8.20 21-Oct-2011
839    ------------------------
840    
841    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
842        a POSIX class. After further experiments with Perl, which convinced me that
843        Perl has bugs and confusions, a closing square bracket is no longer allowed
844        in a POSIX name. This bug also affected patterns with classes that started
845        with full stops.
846    
847    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
848        captured substring, but while checking the failing first alternative,
849        substring 1 is temporarily captured. If the output vector supplied to
850        pcre_exec() was not big enough for this capture, the yield of the function
851        was still zero ("insufficient space for captured substrings"). This cannot
852        be totally fixed without adding another stack variable, which seems a lot
853        of expense for a edge case. However, I have improved the situation in cases
854        such as /(a)(b)x|abc/ matched against "abc", where the return code
855        indicates that fewer than the maximum number of slots in the ovector have
856        been set.
857    
858    3.  Related to (2) above: when there are more back references in a pattern than
859        slots in the output vector, pcre_exec() uses temporary memory during
860        matching, and copies in the captures as far as possible afterwards. It was
861        using the entire output vector, but this conflicts with the specification
862        that only 2/3 is used for passing back captured substrings. Now it uses
863        only the first 2/3, for compatibility. This is, of course, another edge
864        case.
865    
866    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
867        main code base, and can be used by building with --enable-jit. When this is
868        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
869        runtime --no-jit option is given.
870    
871    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
872        ovector, the return from the function was zero, implying that there were
873        other matches that did not fit. The correct "exactly full" value is now
874        returned.
875    
876    6.  If a subpattern that was called recursively or as a subroutine contained
877        (*PRUNE) or any other control that caused it to give a non-standard return,
878        invalid errors such as "Error -26 (nested recursion at the same subject
879        position)" or even infinite loops could occur.
880    
881    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
882        computing the minimum length on reaching *ACCEPT, and so ended up with the
883        wrong value of 1 rather than 0. Further investigation indicates that
884        computing a minimum subject length in the presence of *ACCEPT is difficult
885        (think back references, subroutine calls), and so I have changed the code
886        so that no minimum is registered for a pattern that contains *ACCEPT.
887    
888    8.  If (*THEN) was present in the first (true) branch of a conditional group,
889        it was not handled as intended. [But see 16 below.]
890    
891    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
892        Sheri Pierce.
893    
894    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
895        the first byte in a match must be "a".
896    
897    11. Change 17 for 8.13 increased the recursion depth for patterns like
898        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
899        pattern contains any instances of (*THEN). If it does not, the old
900        optimizations are restored. It would be nice to do this on a per-group
901        basis, but at the moment that is not feasible.
902    
903    12. In some environments, the output of pcretest -C is CRLF terminated. This
904        broke RunTest's code that checks for the link size. A single white space
905        character after the value is now allowed for.
906    
907    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
908        For "fr", it uses the Windows-specific input and output files.
909    
910    14. If (*THEN) appeared in a group that was called recursively or as a
911        subroutine, it did not work as intended. [But see next item.]
912    
913    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
914        pattern fragments (but not containing any | characters). If A and B are
915        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
916        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
917        D. In other words, Perl considers parentheses that do not contain any |
918        characters to be part of a surrounding alternative, whereas PCRE was
919        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
920        differently. PCRE now behaves in the same way as Perl, except in the case
921        of subroutine/recursion calls such as (?1) which have in any case always
922        been different (but PCRE had them first :-).
923    
924    16. Related to 15 above: Perl does not treat the | in a conditional group as
925        creating alternatives. Such a group is treated in the same way as an
926        ordinary group without any | characters when processing (*THEN). PCRE has
927        been changed to match Perl's behaviour.
928    
929    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
930        RunGrepTest script failed.
931    
932    18. Change 22 for version 13 caused atomic groups to use more stack. This is
933        inevitable for groups that contain captures, but it can lead to a lot of
934        stack use in large patterns. The old behaviour has been restored for atomic
935        groups that do not contain any capturing parentheses.
936    
937    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
938        suppress the check for a minimum subject length at run time. (If it was
939        given to pcre_exec() or pcre_dfa_exec() it did work.)
940    
941    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
942        fail to work when decoding hex characters in data strings in EBCDIC
943        environments.
944    
945    21. It appears that in at least one Mac OS environment, the isxdigit() function
946        is implemented as a macro that evaluates to its argument more than once,
947        contravening the C 90 Standard (I haven't checked a later standard). There
948        was an instance in pcretest which caused it to go wrong when processing
949        \x{...} escapes in subject strings. The has been rewritten to avoid using
950        things like p++ in the argument of isxdigit().
951    
952    
953    Version 8.13 16-Aug-2011
954  ------------------------  ------------------------
955    
956  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 20  Version 8.13 30-Apr-2011 Line 969  Version 8.13 30-Apr-2011
969      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
970      2-byte code at the end of the subject (it thought there wasn't enough data      2-byte code at the end of the subject (it thought there wasn't enough data
971      left).      left).
972    
973  5.  Comprehensive information about what went wrong is now returned by  5.  Comprehensive information about what went wrong is now returned by
974      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
975      as the output vector has at least 2 elements. The offset of the start of      as the output vector has at least 2 elements. The offset of the start of
976      the failing character and a reason code are placed in the vector.      the failing character and a reason code are placed in the vector.
977    
978  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
979      now returned is for the first byte of the failing character, instead of the      now returned is for the first byte of the failing character, instead of the
980      last byte inspected. This is an incompatible change, but I hope it is small      last byte inspected. This is an incompatible change, but I hope it is small
981      enough not to be a problem. It makes the returned offset consistent with      enough not to be a problem. It makes the returned offset consistent with
982      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
983    
984  7.  pcretest now gives a text phrase as well as the error number when  7.  pcretest now gives a text phrase as well as the error number when
985      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
986      failure, the offset and reason code are output.      failure, the offset and reason code are output.
987    
988  8.  When \R was used with a maximizing quantifier it failed to skip backwards  8.  When \R was used with a maximizing quantifier it failed to skip backwards
989      over a \r\n pair if the subsequent match failed. Instead, it just skipped      over a \r\n pair if the subsequent match failed. Instead, it just skipped
990      back over a single character (\n). This seems wrong (because it treated the      back over a single character (\n). This seems wrong (because it treated the
991      two characters as a single entity when going forwards), conflicts with the      two characters as a single entity when going forwards), conflicts with the
992      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
993      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
994      has been changed.      has been changed.
995    
996  9.  Some internal refactoring has changed the processing so that the handling  9.  Some internal refactoring has changed the processing so that the handling
997      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
998      time (the PCRE_DOTALL option was changed this way some time ago: version      time (the PCRE_DOTALL option was changed this way some time ago: version
999      7.7 change 16). This has made it possible to abolish the OP_OPT op code,      7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1000      which was always a bit of a fudge. It also means that there is one less      which was always a bit of a fudge. It also means that there is one less
1001      argument for the match() function, which reduces its stack requirements      argument for the match() function, which reduces its stack requirements
1002      slightly. This change also fixes an incompatibility with Perl: the pattern      slightly. This change also fixes an incompatibility with Perl: the pattern
1003      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1004    
1005  10. More internal refactoring has drastically reduced the number of recursive  10. More internal refactoring has drastically reduced the number of recursive
1006      calls to match() for possessively repeated groups such as (abc)++ when      calls to match() for possessively repeated groups such as (abc)++ when
1007      using pcre_exec().      using pcre_exec().
1008    
1009  11. While implementing 10, a number of bugs in the handling of groups were  11. While implementing 10, a number of bugs in the handling of groups were
1010      discovered and fixed:      discovered and fixed:
1011    
1012      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1013      (a|)*(?1) gave a compile-time internal error.      (a|)*(?1) gave a compile-time internal error.
1014      ((a|)+)+  did not notice that the outer group could match an empty string.      ((a|)+)+  did not notice that the outer group could match an empty string.
1015      (^a|^)+   was not marked as anchored.      (^a|^)+   was not marked as anchored.
1016      (.*a|.*)+ was not marked as matching at start or after a newline.      (.*a|.*)+ was not marked as matching at start or after a newline.
1017    
1018  12. Yet more internal refactoring has removed another argument from the match()  12. Yet more internal refactoring has removed another argument from the match()
1019      function. Special calls to this function are now indicated by setting a      function. Special calls to this function are now indicated by setting a
1020      value in a variable in the "match data" data block.      value in a variable in the "match data" data block.
1021    
1022  13. Be more explicit in pcre_study() instead of relying on "default" for  13. Be more explicit in pcre_study() instead of relying on "default" for
1023      opcodes that mean there is no starting character; this means that when new      opcodes that mean there is no starting character; this means that when new
1024      ones are added and accidentally left out of pcre_study(), testing should      ones are added and accidentally left out of pcre_study(), testing should
1025      pick them up.      pick them up.
1026    
1027  14. The -s option of pcretest has been documented for ages as being an old  14. The -s option of pcretest has been documented for ages as being an old
1028      synonym of -m (show memory usage). I have changed it to mean "force study      synonym of -m (show memory usage). I have changed it to mean "force study
1029      for every regex", that is, assume /S for every regex. This is similar to -i      for every regex", that is, assume /S for every regex. This is similar to -i
1030      and -d etc. It's slightly incompatible, but I'm hoping nobody is still      and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1031      using it. It makes it easier to run collection of tests with study enabled,      using it. It makes it easier to run collections of tests with and without
1032      and thereby test pcre_study() more easily.      study enabled, and thereby test pcre_study() more easily. All the standard
1033        tests are now run with and without -s (but some patterns can be marked as
1034        "never study" - see 20 below).
1035    
1036  15. When (*ACCEPT) was used in a subpattern that was called recursively, the  15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1037      restoration of the capturing data to the outer values was not happening      restoration of the capturing data to the outer values was not happening
1038      correctly.      correctly.
1039    
1040  16. If a recursively called subpattern ended with (*ACCEPT) and matched an  16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1041      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1042      pattern had matched an empty string, and so incorrectly returned a no      pattern had matched an empty string, and so incorrectly returned a no
1043      match.      match.
1044    
1045    17. There was optimizing code for the last branch of non-capturing parentheses,
1046        and also for the obeyed branch of a conditional subexpression, which used
1047        tail recursion to cut down on stack usage. Unfortunately, now that there is
1048        the possibility of (*THEN) occurring in these branches, tail recursion is
1049        no longer possible because the return has to be checked for (*THEN). These
1050        two optimizations have therefore been removed. [But see 8.20/11 above.]
1051    
1052    18. If a pattern containing \R was studied, it was assumed that \R always
1053        matched two bytes, thus causing the minimum subject length to be
1054        incorrectly computed because \R can also match just one byte.
1055    
1056    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1057        was incorrectly computed.
1058    
1059    20. If /S is present twice on a test pattern in pcretest input, it now
1060        *disables* studying, thereby overriding the use of -s on the command line
1061        (see 14 above). This is necessary for one or two tests to keep the output
1062        identical in both cases.
1063    
1064    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1065        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1066    
1067    22. When an atomic group that contained a capturing parenthesis was
1068        successfully matched, but the branch in which it appeared failed, the
1069        capturing was not being forgotten if a higher numbered group was later
1070        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1071        group 1 to "a", when in fact it should be unset. This applied to multi-
1072        branched capturing and non-capturing groups, repeated or not, and also to
1073        positive assertions (capturing in negative assertions does not happen
1074        in PCRE) and also to nested atomic groups.
1075    
1076    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1077        subject after a captured substring, to make it easier to tell which of a
1078        number of identical substrings has been captured.
1079    
1080    24. The way atomic groups are processed by pcre_exec() has been changed so that
1081        if they are repeated, backtracking one repetition now resets captured
1082        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1083        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1084        "aaa". Previously, it would have been "a". As part of this code
1085        refactoring, the way recursive calls are handled has also been changed.
1086    
1087    25. If an assertion condition captured any substrings, they were not passed
1088        back unless some other capturing happened later. For example, if
1089        (?(?=(a))a) was matched against "a", no capturing was returned.
1090    
1091    26. When studying a pattern that contained subroutine calls or assertions,
1092        the code for finding the minimum length of a possible match was handling
1093        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1094        group 1 called group 2 while simultaneously a separate group 2 called group
1095        1). A stack overflow occurred in this case. I have fixed this by limiting
1096        the recursion depth to 10.
1097    
1098    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1099        Fortmann. This supports explicit test numbers on the command line, and has
1100        argument validation and error reporting.
1101    
1102    28. An instance of \X with an unlimited repeat could fail if at any point the
1103        first character it looked at was a mark character.
1104    
1105    29. Some minor code refactoring concerning Unicode properties and scripts
1106        should reduce the stack requirement of match() slightly.
1107    
1108    30. Added the '=' option to pcretest to check the setting of unused capturing
1109        slots at the end of the pattern, which are documented as being -1, but are
1110        not included in the return count.
1111    
1112    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1113        compiled something random. Now it gives a compile-time error (as does
1114        Perl).
1115    
1116    32. A *MARK encountered during the processing of a positive assertion is now
1117        recorded and passed back (compatible with Perl).
1118    
1119    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1120        had alternative anchored branches, the search for a second match in a line
1121        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1122        matched the line "0102" twice. The same bug affected patterns that started
1123        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1124        twice.
1125    
1126    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1127        does, and because of capturing effects, quantifying parenthesized
1128        assertions may at times be useful. Quantifiers are now allowed for
1129        parenthesized assertions.
1130    
1131    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1132    
1133    36. \g was being checked for fancy things in a character class, when it should
1134        just be a literal "g".
1135    
1136    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1137        appearance of a nested POSIX class supersedes an apparent external class.
1138        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1139        unescaped square brackets may also appear as part of class names. For
1140        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1141        more like Perl. (But see 8.20/1 above.)
1142    
1143    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1144        was because it thought it was \N{name}, which is not supported).
1145    
1146    39. Add minix to OS list not supporting the -S option in pcretest.
1147    
1148    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1149        cannot analyze patterns in sufficient detail to catch mutual recursions
1150        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1151        subgroup is called recursively as a subpattern for a second time at the
1152        same position in the subject string. In previous releases this might have
1153        been caught by the recursion limit, or it might have run out of stack.
1154    
1155    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1156        happen only once. PCRE was, however incorrectly giving a compile time error
1157        "recursive call could loop indefinitely" because it cannot analyze the
1158        pattern in sufficient detail. The compile time test no longer happens when
1159        PCRE is compiling a conditional subpattern, but actual runaway loops are
1160        now caught at runtime (see 40 above).
1161    
1162    42. It seems that Perl allows any characters other than a closing parenthesis
1163        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1164        has been changed to be the same.
1165    
1166    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1167        as not to get warnings when autogen.sh is called. Also changed
1168        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1169    
1170    44. To help people who use pcregrep to scan files containing exceedingly long
1171        lines, the following changes have been made:
1172    
1173        (a) The default value of the buffer size parameter has been increased from
1174            8K to 20K. (The actual buffer used is three times this size.)
1175    
1176        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1177            PCRE is built.
1178    
1179        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1180            to be set at run time.
1181    
1182        (d) Numerical values in pcregrep options can be followed by K or M, for
1183            example --buffer-size=50K.
1184    
1185        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1186            given and the return code is set to 2.
1187    
1188    45. Add a pointer to the latest mark to the callout data block.
1189    
1190    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1191        partial match of an empty string instead of no match. This was specific to
1192        the use of ".".
1193    
1194    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1195        complete match instead of a partial match. This bug was dependent on both
1196        the PCRE_UTF8 and PCRE_DOTALL options being set.
1197    
1198    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1199        starting byte set, because \b was not being ignored.
1200    
1201    
1202  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
1203  ------------------------  ------------------------
# Line 742  Version 7.9 11-Apr-09 Line 1849  Version 7.9 11-Apr-09
1849  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
1850      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
1851      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1852      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1853        8.33.]
1854    
1855  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
1856      start or after a newline", because the conditional assertion was not being      start or after a newline", because the conditional assertion was not being
# Line 985  Version 7.7 07-May-08 Line 2093  Version 7.7 07-May-08
2093      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2094      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2095      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2096      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2097      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2098      was subsequently set up correctly.)      was subsequently set up correctly.)
2099    

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