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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.11 10-Oct-2010  Version 8.32
5    ------------
6    
7    1.  Improved JIT compiler optimizations for first character search and single
8        character iterators.
9    
10    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11        Patch by Daniel Richard G.
12    
13    3.  Single character iterator optimizations in the JIT compiler.
14    
15    4.  Improved JIT compiler optimizations for character ranges.
16    
17    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
18        Reported by Giuseppe D'Angelo.
19    
20    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
21        of a line, was being set incorrectly in cases where .* appeared inside
22        atomic brackets at the start of a pattern, or where there was a subsequent
23        *PRUNE or *SKIP.
24    
25    
26    Version 8.31 06-July-2012
27    -------------------------
28    
29    1.  Fixing a wrong JIT test case and some compiler warnings.
30    
31    2.  Removed a bashism from the RunTest script.
32    
33    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
34        to unsigned type, result still unsigned" that was given by an MS compiler
35        on encountering the code "-sizeof(xxx)".
36    
37    4.  Partial matching support is added to the JIT compiler.
38    
39    5.  Fixed several bugs concerned with partial matching of items that consist
40        of more than one character:
41    
42        (a) /^(..)\1/ did not partially match "aba" because checking references was
43            done on an "all or nothing" basis. This also applied to repeated
44            references.
45    
46        (b) \R did not give a hard partial match if \r was found at the end of the
47            subject.
48    
49        (c) \X did not give a hard partial match after matching one or more
50            characters at the end of the subject.
51    
52        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
53            a partial match for the string "\r".
54    
55        (e) When newline was set to CRLF, the metacharacter "." did not recognize
56            a partial match for a CR character at the end of the subject string.
57    
58    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
59        running pcretest, the text "(JIT)" added to the output whenever JIT is
60        actually used to run the match.
61    
62    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
63        or /S+[+] with a digit between 1 and 7.
64    
65    8.  OP_NOT now supports any UTF character not just single-byte ones.
66    
67    9.  (*MARK) control verb is now supported by the JIT compiler.
68    
69    10. The command "./RunTest list" lists the available tests without actually
70        running any of them. (Because I keep forgetting what they all are.)
71    
72    11. Add PCRE_INFO_MAXLOOKBEHIND.
73    
74    12. Applied a (slightly modified) user-supplied patch that improves performance
75        when the heap is used for recursion (compiled with --disable-stack-for-
76        recursion). Instead of malloc and free for each heap frame each time a
77        logical recursion happens, frames are retained on a chain and re-used where
78        possible. This sometimes gives as much as 30% improvement.
79    
80    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
81        call.
82    
83    14. As documented, (*COMMIT) is now confined to within a positive assertion.
84    
85    15. It is now possible to link pcretest with libedit as an alternative to
86        libreadline.
87    
88    16. (*COMMIT) control verb is now supported by the JIT compiler.
89    
90    17. The Unicode data tables have been updated to Unicode 6.1.0.
91    
92    18. Added --file-list option to pcregrep.
93    
94    19. Added binary file support to pcregrep, including the -a, --binary-files,
95        -I, and --text options.
96    
97    20. The madvise function is renamed for posix_madvise for QNX compatibility
98        reasons. Fixed by Giuseppe D'Angelo.
99    
100    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
101    
102    22. Changed the option for creating symbolic links for 16-bit man pages from
103        -s to -sf so that re-installing does not cause issues.
104    
105    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
106    
107    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
108        matches in certain environments (the workspace was not being correctly
109        retained). Also added to pcre_dfa_exec() a simple plausibility check on
110        some of the workspace data at the beginning of a restart.
111    
112    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
113        was not doing so when it should - probably a typo introduced by SVN 528
114        (change 8.10/14).
115    
116    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
117        \w+ when the character tables indicated that \x{c4} was a word character.
118        There were several related cases, all because the tests for doing a table
119        lookup were testing for characters less than 127 instead of 255.
120    
121    27. If a pattern contains capturing parentheses that are not used in a match,
122        their slots in the ovector are set to -1. For those that are higher than
123        any matched groups, this happens at the end of processing. In the case when
124        there were back references that the ovector was too small to contain
125        (causing temporary malloc'd memory to be used during matching), and the
126        highest capturing number was not used, memory off the end of the ovector
127        was incorrectly being set to -1. (It was using the size of the temporary
128        memory instead of the true size.)
129    
130    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
131        ovector size, it uses memory at the end of the block that it has got.
132    
133    29. Check for an overlong MARK name and give an error at compile time. The
134        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
135    
136    30. JIT compiler update.
137    
138    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
139        Rill for the patch.
140    
141    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
142    
143    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
144    
145    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
146        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
147        was enabled.
148    
149    35. Improve JIT code generation for greedy plus quantifier.
150    
151    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
152        1 to "aa" instead of to an empty string. The bug affected repeated groups
153        that could potentially match an empty string.
154    
155    37. Optimizing single character iterators in JIT.
156    
157    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
158        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
159        codepoints that are too big for the mode are faulted, and in a UTF mode,
160        disallowed codepoints are also faulted.
161    
162    39. If PCRE was compiled with UTF support, in three places in the DFA
163        matcher there was code that should only have been obeyed in UTF mode, but
164        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
165        processing when bytes with values greater than 127 were present. In 16-bit
166        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
167        both cases the values are those that cannot be the first data item in a UTF
168        character. The three items that might have provoked this were recursions,
169        possessively repeated groups, and atomic groups.
170    
171    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
172        and pcregrep, because some OS require shared objects to be explicitly
173        passed to ld, causing the link step to fail if they are not.
174    
175    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
176        mode, patterns that started with \h* or \R* might be incorrectly matched.
177    
178    
179    Version 8.30 04-February-2012
180    -----------------------------
181    
182    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
183        name is defined in ctype.h.
184    
185    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
186        only in quite long subpatterns.
187    
188    3.  Removed the function pcre_info(), which has been obsolete and deprecated
189        since it was replaced by pcre_fullinfo() in February 2000.
190    
191    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
192        match a (*MARK), and the match failed at the start of the subject, a
193        reference to memory before the start of the subject could occur. This bug
194        was introduced by fix 17 of release 8.21.
195    
196    5.  A reference to an unset group with zero minimum repetition was giving
197        totally wrong answers (in non-JavaScript-compatibility mode). For example,
198        /(another)?(\1?)test/ matched against "hello world test". This bug was
199        introduced in release 8.13.
200    
201    6.  Add support for 16-bit character strings (a large amount of work involving
202        many changes and refactorings).
203    
204    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
205        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
206        from a file.
207    
208    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
209        rounding is not applied in this particular case).
210    
211    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
212        if they appear, or are escaped, in patterns.
213    
214    10. Get rid of a number of -Wunused-but-set-variable warnings.
215    
216    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
217        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
218        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
219        also returns the mark "x". This bug applied to capturing parentheses,
220        non-capturing parentheses, and atomic parentheses. It also applied to some
221        assertions.
222    
223    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
224        information out of configure.ac instead of relying on pcre.h.generic, which
225        is not stored in the repository.
226    
227    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
228        -lreadline.
229    
230    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
231    
232    15. Applied Graycode's patch to put the top-level frame on the stack rather
233        than the heap when not using the stack for recursion. This gives a
234        performance improvement in many cases when recursion is not deep.
235    
236    16. Experimental code added to "pcretest -C" to output the stack frame size.
237    
238    
239    Version 8.21 12-Dec-2011
240    ------------------------
241    
242    1.  Updating the JIT compiler.
243    
244    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
245        are added as well.
246    
247    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
248        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
249        calling _pcre_jit_exec. Some extra comments are added.
250    
251    4.  (*MARK) settings inside atomic groups that do not contain any capturing
252        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
253        was introduced by change 18 for 8.20.
254    
255    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
256        ECMA-262 standard.
257    
258    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
259        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
260        This bug was probably introduced by change 9 of 8.13.
261    
262    7.  While fixing 6 above, I noticed that a number of other items were being
263        incorrectly rejected as "not fixed length". This arose partly because newer
264        opcodes had not been added to the fixed-length checking code. I have (a)
265        corrected the bug and added tests for these items, and (b) arranged for an
266        error to occur if an unknown opcode is encountered while checking for fixed
267        length instead of just assuming "not fixed length". The items that were
268        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
269        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
270        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
271    
272    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
273        being incorrectly compiled and would have given unpredicatble results.
274    
275    9.  A possessively repeated subpattern with minimum repeat count greater than
276        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
277        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
278        the first (A) could occur when it should not.
279    
280    10. Add a cast and remove a redundant test from the code.
281    
282    11. JIT should use pcre_malloc/pcre_free for allocation.
283    
284    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
285        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
286        is anything other than /usr, -L is still shown).
287    
288    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
289    
290    14. Perl does not support \N without a following name in a [] class; PCRE now
291        also gives an error.
292    
293    15. If a forward reference was repeated with an upper limit of around 2000,
294        it caused the error "internal error: overran compiling workspace". The
295        maximum number of forward references (including repeats) was limited by the
296        internal workspace, and dependent on the LINK_SIZE. The code has been
297        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
298        the default depends on LINK_SIZE. There is a new upper limit (for safety)
299        of around 200,000 forward references. While doing this, I also speeded up
300        the filling in of repeated forward references.
301    
302    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
303        incorrectly expecting the subject to contain another "a" after the start.
304    
305    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
306        in the match, the SKIP should be ignored. This was not happening; instead
307        the SKIP was being treated as NOMATCH. For patterns such as
308        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
309        tested.
310    
311    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
312        now much more compatible with Perl, in particular in cases where the result
313        is a non-match for a non-anchored pattern. For example, if
314        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
315        "m", where previously it did not return a name. A side effect of this
316        change is that for partial matches, the last encountered mark name is
317        returned, as for non matches. A number of tests that were previously not
318        Perl-compatible have been moved into the Perl-compatible test files. The
319        refactoring has had the pleasing side effect of removing one argument from
320        the match() function, thus reducing its stack requirements.
321    
322    19. If the /S+ option was used in pcretest to study a pattern using JIT,
323        subsequent uses of /S (without +) incorrectly behaved like /S+.
324    
325    21. Retrieve executable code size support for the JIT compiler and fixing
326        some warnings.
327    
328    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
329        not work when the shorter character appeared right at the end of the
330        subject string.
331    
332    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
333        systems.
334    
335    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
336        output it when the /M option is used in pcretest.
337    
338    25. The CheckMan script was not being included in the distribution. Also, added
339        an explicit "perl" to run Perl scripts from the PrepareRelease script
340        because this is reportedly needed in Windows.
341    
342    26. If study data was being save in a file and studying had not found a set of
343        "starts with" bytes for the pattern, the data written to the file (though
344        never used) was taken from uninitialized memory and so caused valgrind to
345        complain.
346    
347    27. Updated RunTest.bat as provided by Sheri Pierce.
348    
349    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
350    
351    29. Computation of memory usage for the table of capturing group names was
352        giving an unnecessarily large value.
353    
354    
355    Version 8.20 21-Oct-2011
356    ------------------------
357    
358    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
359        a POSIX class. After further experiments with Perl, which convinced me that
360        Perl has bugs and confusions, a closing square bracket is no longer allowed
361        in a POSIX name. This bug also affected patterns with classes that started
362        with full stops.
363    
364    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
365        captured substring, but while checking the failing first alternative,
366        substring 1 is temporarily captured. If the output vector supplied to
367        pcre_exec() was not big enough for this capture, the yield of the function
368        was still zero ("insufficient space for captured substrings"). This cannot
369        be totally fixed without adding another stack variable, which seems a lot
370        of expense for a edge case. However, I have improved the situation in cases
371        such as /(a)(b)x|abc/ matched against "abc", where the return code
372        indicates that fewer than the maximum number of slots in the ovector have
373        been set.
374    
375    3.  Related to (2) above: when there are more back references in a pattern than
376        slots in the output vector, pcre_exec() uses temporary memory during
377        matching, and copies in the captures as far as possible afterwards. It was
378        using the entire output vector, but this conflicts with the specification
379        that only 2/3 is used for passing back captured substrings. Now it uses
380        only the first 2/3, for compatibility. This is, of course, another edge
381        case.
382    
383    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
384        main code base, and can be used by building with --enable-jit. When this is
385        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
386        runtime --no-jit option is given.
387    
388    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
389        ovector, the return from the function was zero, implying that there were
390        other matches that did not fit. The correct "exactly full" value is now
391        returned.
392    
393    6.  If a subpattern that was called recursively or as a subroutine contained
394        (*PRUNE) or any other control that caused it to give a non-standard return,
395        invalid errors such as "Error -26 (nested recursion at the same subject
396        position)" or even infinite loops could occur.
397    
398    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
399        computing the minimum length on reaching *ACCEPT, and so ended up with the
400        wrong value of 1 rather than 0. Further investigation indicates that
401        computing a minimum subject length in the presence of *ACCEPT is difficult
402        (think back references, subroutine calls), and so I have changed the code
403        so that no minimum is registered for a pattern that contains *ACCEPT.
404    
405    8.  If (*THEN) was present in the first (true) branch of a conditional group,
406        it was not handled as intended. [But see 16 below.]
407    
408    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
409        Sheri Pierce.
410    
411    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
412        the first byte in a match must be "a".
413    
414    11. Change 17 for 8.13 increased the recursion depth for patterns like
415        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
416        pattern contains any instances of (*THEN). If it does not, the old
417        optimizations are restored. It would be nice to do this on a per-group
418        basis, but at the moment that is not feasible.
419    
420    12. In some environments, the output of pcretest -C is CRLF terminated. This
421        broke RunTest's code that checks for the link size. A single white space
422        character after the value is now allowed for.
423    
424    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
425        For "fr", it uses the Windows-specific input and output files.
426    
427    14. If (*THEN) appeared in a group that was called recursively or as a
428        subroutine, it did not work as intended. [But see next item.]
429    
430    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
431        pattern fragments (but not containing any | characters). If A and B are
432        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
433        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
434        D. In other words, Perl considers parentheses that do not contain any |
435        characters to be part of a surrounding alternative, whereas PCRE was
436        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
437        differently. PCRE now behaves in the same way as Perl, except in the case
438        of subroutine/recursion calls such as (?1) which have in any case always
439        been different (but PCRE had them first :-).
440    
441    16. Related to 15 above: Perl does not treat the | in a conditional group as
442        creating alternatives. Such a group is treated in the same way as an
443        ordinary group without any | characters when processing (*THEN). PCRE has
444        been changed to match Perl's behaviour.
445    
446    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
447        RunGrepTest script failed.
448    
449    18. Change 22 for version 13 caused atomic groups to use more stack. This is
450        inevitable for groups that contain captures, but it can lead to a lot of
451        stack use in large patterns. The old behaviour has been restored for atomic
452        groups that do not contain any capturing parentheses.
453    
454    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
455        suppress the check for a minimum subject length at run time. (If it was
456        given to pcre_exec() or pcre_dfa_exec() it did work.)
457    
458    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
459        fail to work when decoding hex characters in data strings in EBCDIC
460        environments.
461    
462    21. It appears that in at least one Mac OS environment, the isxdigit() function
463        is implemented as a macro that evaluates to its argument more than once,
464        contravening the C 90 Standard (I haven't checked a later standard). There
465        was an instance in pcretest which caused it to go wrong when processing
466        \x{...} escapes in subject strings. The has been rewritten to avoid using
467        things like p++ in the argument of isxdigit().
468    
469    
470    Version 8.13 16-Aug-2011
471    ------------------------
472    
473    1.  The Unicode data tables have been updated to Unicode 6.0.0.
474    
475    2.  Two minor typos in pcre_internal.h have been fixed.
476    
477    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
478        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
479        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
480    
481    4.  There were a number of related bugs in the code for matching backrefences
482        caselessly in UTF-8 mode when codes for the characters concerned were
483        different numbers of bytes. For example, U+023A and U+2C65 are an upper
484        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
485        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
486        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
487        2-byte code at the end of the subject (it thought there wasn't enough data
488        left).
489    
490    5.  Comprehensive information about what went wrong is now returned by
491        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
492        as the output vector has at least 2 elements. The offset of the start of
493        the failing character and a reason code are placed in the vector.
494    
495    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
496        now returned is for the first byte of the failing character, instead of the
497        last byte inspected. This is an incompatible change, but I hope it is small
498        enough not to be a problem. It makes the returned offset consistent with
499        pcre_exec() and pcre_dfa_exec().
500    
501    7.  pcretest now gives a text phrase as well as the error number when
502        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
503        failure, the offset and reason code are output.
504    
505    8.  When \R was used with a maximizing quantifier it failed to skip backwards
506        over a \r\n pair if the subsequent match failed. Instead, it just skipped
507        back over a single character (\n). This seems wrong (because it treated the
508        two characters as a single entity when going forwards), conflicts with the
509        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
510        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
511        has been changed.
512    
513    9.  Some internal refactoring has changed the processing so that the handling
514        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
515        time (the PCRE_DOTALL option was changed this way some time ago: version
516        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
517        which was always a bit of a fudge. It also means that there is one less
518        argument for the match() function, which reduces its stack requirements
519        slightly. This change also fixes an incompatibility with Perl: the pattern
520        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
521    
522    10. More internal refactoring has drastically reduced the number of recursive
523        calls to match() for possessively repeated groups such as (abc)++ when
524        using pcre_exec().
525    
526    11. While implementing 10, a number of bugs in the handling of groups were
527        discovered and fixed:
528    
529        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
530        (a|)*(?1) gave a compile-time internal error.
531        ((a|)+)+  did not notice that the outer group could match an empty string.
532        (^a|^)+   was not marked as anchored.
533        (.*a|.*)+ was not marked as matching at start or after a newline.
534    
535    12. Yet more internal refactoring has removed another argument from the match()
536        function. Special calls to this function are now indicated by setting a
537        value in a variable in the "match data" data block.
538    
539    13. Be more explicit in pcre_study() instead of relying on "default" for
540        opcodes that mean there is no starting character; this means that when new
541        ones are added and accidentally left out of pcre_study(), testing should
542        pick them up.
543    
544    14. The -s option of pcretest has been documented for ages as being an old
545        synonym of -m (show memory usage). I have changed it to mean "force study
546        for every regex", that is, assume /S for every regex. This is similar to -i
547        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
548        using it. It makes it easier to run collections of tests with and without
549        study enabled, and thereby test pcre_study() more easily. All the standard
550        tests are now run with and without -s (but some patterns can be marked as
551        "never study" - see 20 below).
552    
553    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
554        restoration of the capturing data to the outer values was not happening
555        correctly.
556    
557    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
558        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
559        pattern had matched an empty string, and so incorrectly returned a no
560        match.
561    
562    17. There was optimizing code for the last branch of non-capturing parentheses,
563        and also for the obeyed branch of a conditional subexpression, which used
564        tail recursion to cut down on stack usage. Unfortunately, now that there is
565        the possibility of (*THEN) occurring in these branches, tail recursion is
566        no longer possible because the return has to be checked for (*THEN). These
567        two optimizations have therefore been removed. [But see 8.20/11 above.]
568    
569    18. If a pattern containing \R was studied, it was assumed that \R always
570        matched two bytes, thus causing the minimum subject length to be
571        incorrectly computed because \R can also match just one byte.
572    
573    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
574        was incorrectly computed.
575    
576    20. If /S is present twice on a test pattern in pcretest input, it now
577        *disables* studying, thereby overriding the use of -s on the command line
578        (see 14 above). This is necessary for one or two tests to keep the output
579        identical in both cases.
580    
581    21. When (*ACCEPT) was used in an assertion that matched an empty string and
582        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
583    
584    22. When an atomic group that contained a capturing parenthesis was
585        successfully matched, but the branch in which it appeared failed, the
586        capturing was not being forgotten if a higher numbered group was later
587        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
588        group 1 to "a", when in fact it should be unset. This applied to multi-
589        branched capturing and non-capturing groups, repeated or not, and also to
590        positive assertions (capturing in negative assertions does not happen
591        in PCRE) and also to nested atomic groups.
592    
593    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
594        subject after a captured substring, to make it easier to tell which of a
595        number of identical substrings has been captured.
596    
597    24. The way atomic groups are processed by pcre_exec() has been changed so that
598        if they are repeated, backtracking one repetition now resets captured
599        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
600        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
601        "aaa". Previously, it would have been "a". As part of this code
602        refactoring, the way recursive calls are handled has also been changed.
603    
604    25. If an assertion condition captured any substrings, they were not passed
605        back unless some other capturing happened later. For example, if
606        (?(?=(a))a) was matched against "a", no capturing was returned.
607    
608    26. When studying a pattern that contained subroutine calls or assertions,
609        the code for finding the minimum length of a possible match was handling
610        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
611        group 1 called group 2 while simultaneously a separate group 2 called group
612        1). A stack overflow occurred in this case. I have fixed this by limiting
613        the recursion depth to 10.
614    
615    27. Updated RunTest.bat in the distribution to the version supplied by Tom
616        Fortmann. This supports explicit test numbers on the command line, and has
617        argument validation and error reporting.
618    
619    28. An instance of \X with an unlimited repeat could fail if at any point the
620        first character it looked at was a mark character.
621    
622    29. Some minor code refactoring concerning Unicode properties and scripts
623        should reduce the stack requirement of match() slightly.
624    
625    30. Added the '=' option to pcretest to check the setting of unused capturing
626        slots at the end of the pattern, which are documented as being -1, but are
627        not included in the return count.
628    
629    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
630        compiled something random. Now it gives a compile-time error (as does
631        Perl).
632    
633    32. A *MARK encountered during the processing of a positive assertion is now
634        recorded and passed back (compatible with Perl).
635    
636    33. If --only-matching or --colour was set on a pcregrep call whose pattern
637        had alternative anchored branches, the search for a second match in a line
638        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
639        matched the line "0102" twice. The same bug affected patterns that started
640        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
641        twice.
642    
643    34. Previously, PCRE did not allow quantification of assertions. However, Perl
644        does, and because of capturing effects, quantifying parenthesized
645        assertions may at times be useful. Quantifiers are now allowed for
646        parenthesized assertions.
647    
648    35. A minor code tidy in pcre_compile() when checking options for \R usage.
649    
650    36. \g was being checked for fancy things in a character class, when it should
651        just be a literal "g".
652    
653    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
654        appearance of a nested POSIX class supersedes an apparent external class.
655        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
656        unescaped square brackets may also appear as part of class names. For
657        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
658        more like Perl. (But see 8.20/1 above.)
659    
660    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
661        was because it thought it was \N{name}, which is not supported).
662    
663    39. Add minix to OS list not supporting the -S option in pcretest.
664    
665    40. PCRE tries to detect cases of infinite recursion at compile time, but it
666        cannot analyze patterns in sufficient detail to catch mutual recursions
667        such as ((?1))((?2)). There is now a runtime test that gives an error if a
668        subgroup is called recursively as a subpattern for a second time at the
669        same position in the subject string. In previous releases this might have
670        been caught by the recursion limit, or it might have run out of stack.
671    
672    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
673        happen only once. PCRE was, however incorrectly giving a compile time error
674        "recursive call could loop indefinitely" because it cannot analyze the
675        pattern in sufficient detail. The compile time test no longer happens when
676        PCRE is compiling a conditional subpattern, but actual runaway loops are
677        now caught at runtime (see 40 above).
678    
679    42. It seems that Perl allows any characters other than a closing parenthesis
680        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
681        has been changed to be the same.
682    
683    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
684        as not to get warnings when autogen.sh is called. Also changed
685        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
686    
687    44. To help people who use pcregrep to scan files containing exceedingly long
688        lines, the following changes have been made:
689    
690        (a) The default value of the buffer size parameter has been increased from
691            8K to 20K. (The actual buffer used is three times this size.)
692    
693        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
694            PCRE is built.
695    
696        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
697            to be set at run time.
698    
699        (d) Numerical values in pcregrep options can be followed by K or M, for
700            example --buffer-size=50K.
701    
702        (e) If a line being scanned overflows pcregrep's buffer, an error is now
703            given and the return code is set to 2.
704    
705    45. Add a pointer to the latest mark to the callout data block.
706    
707    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
708        partial match of an empty string instead of no match. This was specific to
709        the use of ".".
710    
711    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
712        complete match instead of a partial match. This bug was dependent on both
713        the PCRE_UTF8 and PCRE_DOTALL options being set.
714    
715    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
716        starting byte set, because \b was not being ignored.
717    
718    
719    Version 8.12 15-Jan-2011
720    ------------------------
721    
722    1.  Fixed some typos in the markup of the man pages, and wrote a script that
723        checks for such things as part of the documentation building process.
724    
725    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
726        --match-limit and --recursion-limit options (added for 8.11). In
727        particular, this made one of the standard tests fail. (The integer value
728        went into the wrong half of a long int.)
729    
730    3.  If the --colour option was given to pcregrep with -v (invert match), it
731        did strange things, either producing crazy output, or crashing. It should,
732        of course, ignore a request for colour when reporting lines that do not
733        match.
734    
735    4.  Another pcregrep bug caused similar problems if --colour was specified with
736        -M (multiline) and the pattern match finished with a line ending.
737    
738    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
739        matched in multiline mode, the following line was shown as part of the
740        match. This seems wrong, so I have changed it.
741    
742    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
743        the check for further matches in the same line (so they could be coloured)
744        to overrun the end of the current line. If another match was found, it was
745        incorrectly shown (and then shown again when found in the next line).
746    
747    7.  If pcregrep was compiled under Windows, there was a reference to the
748        function pcregrep_exit() before it was defined. I am assuming this was
749        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
750        reported by a user. I've moved the definition above the reference.
751    
752    
753    Version 8.11 10-Dec-2010
754  ------------------------  ------------------------
755    
756  1.  (*THEN) was not working properly if there were untried alternatives prior  1.  (*THEN) was not working properly if there were untried alternatives prior
757      to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it      to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
758      backtracked to try for "b" instead of moving to the next alternative branch      backtracked to try for "b" instead of moving to the next alternative branch
759      at the same level (in this case, to look for "c"). The Perl documentation      at the same level (in this case, to look for "c"). The Perl documentation
760      is clear that when (*THEN) is backtracked onto, it goes to the "next      is clear that when (*THEN) is backtracked onto, it goes to the "next
761      alternative in the innermost enclosing group".      alternative in the innermost enclosing group".
762    
763  2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern  2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
764      such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should      such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
765      result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and      result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
766      (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides      (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
767      (*THEN).      (*THEN).
768    
769  3.  If \s appeared in a character class, it removed the VT character from  3.  If \s appeared in a character class, it removed the VT character from
770      the class, even if it had been included by some previous item, for example      the class, even if it had been included by some previous item, for example
771      in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part      in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
772      of \s, but is part of the POSIX "space" class.)      of \s, but is part of the POSIX "space" class.)
773    
774  4.  A partial match never returns an empty string (because you can always  4.  A partial match never returns an empty string (because you can always
775      match an empty string at the end of the subject); however the checking for      match an empty string at the end of the subject); however the checking for
776      an empty string was starting at the "start of match" point. This has been      an empty string was starting at the "start of match" point. This has been
# Line 31  Version 8.11 10-Oct-2010 Line 780  Version 8.11 10-Oct-2010
780      (previously it gave "no match").      (previously it gave "no match").
781    
782  5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching  5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
783      of $, \z, \Z, \b, and \B. If the match point is at the end of the string,      of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
784      previously a full match would be given. However, setting PCRE_PARTIAL_HARD      previously a full match would be given. However, setting PCRE_PARTIAL_HARD
785      has an implication that the given string is incomplete (because a partial      has an implication that the given string is incomplete (because a partial
786      match is preferred over a full match). For this reason, these items now      match is preferred over a full match). For this reason, these items now
787      give a partial match in this situation. [Aside: previously, the one case      give a partial match in this situation. [Aside: previously, the one case
788      /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial      /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
789      match rather than a full match, which was wrong by the old rules, but is      match rather than a full match, which was wrong by the old rules, but is
790      now correct.]      now correct.]
791    
792  6.  There was a bug in the handling of #-introduced comments, recognized when  6.  There was a bug in the handling of #-introduced comments, recognized when
793      PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.      PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
794      If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose      If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
795      UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when      UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
796      scanning for the end of the comment. (*Character* 0x85 is an "any" newline,      scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
797      but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several      but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
798      places in pcre_compile().      places in pcre_compile().
799    
800  7.  Related to (6) above, when pcre_compile() was skipping #-introduced  7.  Related to (6) above, when pcre_compile() was skipping #-introduced
801      comments when looking ahead for named forward references to subpatterns,      comments when looking ahead for named forward references to subpatterns,
802      the only newline sequence it recognized was NL. It now handles newlines      the only newline sequence it recognized was NL. It now handles newlines
803      according to the set newline convention.      according to the set newline convention.
804    
805  8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the  8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
806      former, but used strtoul(), whereas pcretest avoided strtoul() but did not      former, but used strtoul(), whereas pcretest avoided strtoul() but did not
807      cater for a lack of strerror(). These oversights have been fixed.      cater for a lack of strerror(). These oversights have been fixed.
808    
809  9.  Added --match-limit and --recursion-limit to pcregrep.  9.  Added --match-limit and --recursion-limit to pcregrep.
810    
811  10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.  10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
812    
813  11. When the -o option was used, pcregrep was setting a return code of 1, even  11. When the -o option was used, pcregrep was setting a return code of 1, even
814      when matches were found, and --line-buffered was not being honoured.      when matches were found, and --line-buffered was not being honoured.
815    
816  12. Added an optional parentheses number to the -o and --only-matching options  12. Added an optional parentheses number to the -o and --only-matching options
817      of pcregrep.      of pcregrep.
818    
819  13. Imitating Perl's /g action for multiple matches is tricky when the pattern  13. Imitating Perl's /g action for multiple matches is tricky when the pattern
820      can match an empty string. The code to do it in pcretest and pcredemo      can match an empty string. The code to do it in pcretest and pcredemo
821      needed fixing:      needed fixing:
822    
823      (a) When the newline convention was "crlf", pcretest got it wrong, skipping      (a) When the newline convention was "crlf", pcretest got it wrong, skipping
824          only one byte after an empty string match just before CRLF (this case          only one byte after an empty string match just before CRLF (this case
825          just got forgotten; "any" and "anycrlf" were OK).          just got forgotten; "any" and "anycrlf" were OK).
826    
827      (b) The pcretest code also had a bug, causing it to loop forever in UTF-8      (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
828          mode when an empty string match preceded an ASCII character followed by          mode when an empty string match preceded an ASCII character followed by
829          a non-ASCII character. (The code for advancing by one character rather          a non-ASCII character. (The code for advancing by one character rather
830          than one byte was nonsense.)          than one byte was nonsense.)
831    
832      (c) The pcredemo.c sample program did not have any code at all to handle      (c) The pcredemo.c sample program did not have any code at all to handle
833          the cases when CRLF is a valid newline sequence.          the cases when CRLF is a valid newline sequence.
834    
835  14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given  14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
836      as a starting offset was within the subject string. There is now a new      as a starting offset was within the subject string. There is now a new
837      error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is      error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
838      negative or greater than the length of the string. In order to test this,      negative or greater than the length of the string. In order to test this,
839      pcretest is extended to allow the setting of negative starting offsets.      pcretest is extended to allow the setting of negative starting offsets.
840    
841  15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the  15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
842      starting offset points to the beginning of a UTF-8 character was      starting offset points to the beginning of a UTF-8 character was
843      unnecessarily clumsy. I tidied it up.      unnecessarily clumsy. I tidied it up.
844    
845  16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a  16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
846      bad UTF-8 sequence and one that is incomplete.      bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
847    
848  17. Nobody had reported that the --include_dir option, which was added in  17. Nobody had reported that the --include_dir option, which was added in
849      release 7.7 should have been called --include-dir (hyphen, not underscore)      release 7.7 should have been called --include-dir (hyphen, not underscore)
850      for compatibility with GNU grep. I have changed it to --include-dir, but      for compatibility with GNU grep. I have changed it to --include-dir, but
851      left --include_dir as an undocumented synonym, and the same for      left --include_dir as an undocumented synonym, and the same for
852      --exclude-dir, though that is not available in GNU grep, at least as of      --exclude-dir, though that is not available in GNU grep, at least as of
853      release 2.5.4.      release 2.5.4.
854    
855  18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8  18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
856      characters from a string of bytes) have been redefined so as not to use      characters from a string of bytes) have been redefined so as not to use
857      loops, in order to improve performance in some environments. At the same      loops, in order to improve performance in some environments. At the same
858      time, I abstracted some of the common code into auxiliary macros to save      time, I abstracted some of the common code into auxiliary macros to save
859      repetition (this should not affect the compiled code).      repetition (this should not affect the compiled code).
860    
861  19. If \c was followed by a multibyte UTF-8 character, bad things happened. A  19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
862      compile-time error is now given if \c is not followed by an ASCII      compile-time error is now given if \c is not followed by an ASCII
863      character, that is, a byte less than 128. (In EBCDIC mode, the code is      character, that is, a byte less than 128. (In EBCDIC mode, the code is
864      different, and any byte value is allowed.)      different, and any byte value is allowed.)
865    
866  20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_  20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
867      START_OPTIMIZE option, which is now allowed at compile time - but just      START_OPTIMIZE option, which is now allowed at compile time - but just
868      passed through to pcre_exec() or pcre_dfa_exec(). This makes it available      passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
869      to pcregrep and other applications that have no direct access to PCRE      to pcregrep and other applications that have no direct access to PCRE
870      options. The new /Y option in pcretest sets this option when calling      options. The new /Y option in pcretest sets this option when calling
871      pcre_compile().      pcre_compile().
872    
873    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
874        back references. Groups containing recursive back references were forced to
875        be atomic by that change, but in the case of named groups, the amount of
876        memory required was incorrectly computed, leading to "Failed: internal
877        error: code overflow". This has been fixed.
878    
879    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
880        pcretest.c, to avoid build problems in some Borland environments.
881    
882    
883  Version 8.10 25-Jun-2010  Version 8.10 25-Jun-2010

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