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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.31 02-June-2012
5    -------------------------
6    
7    1.  Fixing a wrong JIT test case and some compiler warnings.
8    
9    2.  Removed a bashism from the RunTest script.
10    
11    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
12        to unsigned type, result still unsigned" that was given by an MS compiler
13        on encountering the code "-sizeof(xxx)".
14    
15    4.  Partial matching support is added to the JIT compiler.
16    
17    5.  Fixed several bugs concerned with partial matching of items that consist
18        of more than one character:
19    
20        (a) /^(..)\1/ did not partially match "aba" because checking references was
21            done on an "all or nothing" basis. This also applied to repeated
22            references.
23    
24        (b) \R did not give a hard partial match if \r was found at the end of the
25            subject.
26    
27        (c) \X did not give a hard partial match after matching one or more
28            characters at the end of the subject.
29    
30        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
31            a partial match for the string "\r".
32    
33        (e) When newline was set to CRLF, the metacharacter "." did not recognize
34            a partial match for a CR character at the end of the subject string.
35    
36    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
37        running pcretest, the text "(JIT)" added to the output whenever JIT is
38        actually used to run the match.
39    
40    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
41        or /S+[+] with a digit between 1 and 7.
42    
43    8.  OP_NOT now supports any UTF character not just single-byte ones.
44    
45    9.  (*MARK) control verb is now supported by the JIT compiler.
46    
47    10. The command "./RunTest list" lists the available tests without actually
48        running any of them. (Because I keep forgetting what they all are.)
49    
50    11. Add PCRE_INFO_MAXLOOKBEHIND.
51    
52    12. Applied a (slightly modified) user-supplied patch that improves performance
53        when the heap is used for recursion (compiled with --disable-stack-for-
54        recursion). Instead of malloc and free for each heap frame each time a
55        logical recursion happens, frames are retained on a chain and re-used where
56        possible. This sometimes gives as much as 30% improvement.
57    
58    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
59        call.
60    
61    14. As documented, (*COMMIT) is now confined to within a positive assertion.
62    
63    15. It is now possible to link pcretest with libedit as an alternative to
64        libreadline.
65    
66    16. (*COMMIT) control verb is now supported by the JIT compiler.
67    
68    17. The Unicode data tables have been updated to Unicode 6.1.0.
69    
70    18. Added --file-list option to pcregrep.
71    
72    19. Added binary file support to pcregrep, including the -a, --binary-files,
73        -I, and --text options.
74    
75    20. The madvise function is renamed for posix_madvise for QNX compatibility
76        reasons. Fixed by Giuseppe D'Angelo.
77    
78    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
79    
80    22. Changed the option for creating symbolic links for 16-bit man pages from
81        -s to -sf so that re-installing does not cause issues.
82    
83    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
84    
85    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
86        matches in certain environments (the workspace was not being correctly
87        retained). Also added to pcre_dfa_exec() a simple plausibility check on
88        some of the workspace data at the beginning of a restart.
89    
90    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
91        was not doing so when it should - probably a typo introduced by SVN 528
92        (change 8.10/14).
93    
94    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
95        \w+ when the character tables indicated that \x{c4} was a word character.
96        There were several related cases, all because the tests for doing a table
97        lookup were testing for characters less than 127 instead of 255.
98    
99    27. If a pattern contains capturing parentheses that are not used in a match,
100        their slots in the ovector are set to -1. For those that are higher than
101        any matched groups, this happens at the end of processing. In the case when
102        there were back references that the ovector was too small to contain
103        (causing temporary malloc'd memory to be used during matching), and the
104        highest capturing number was not used, memory off the end of the ovector
105        was incorrectly being set to -1. (It was using the size of the temporary
106        memory instead of the true size.)
107    
108    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
109        ovector size, it uses memory at the end of the block that it has got.
110    
111    29. Check for an overlong MARK name and give an error at compile time. The
112        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
113    
114    30. JIT compiler update.
115    
116    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
117        Rill for the patch.
118    
119    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
120    
121    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
122    
123    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
124        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
125        was enabled.
126    
127    35. Improve JIT code generation for greedy plus quantifier.
128    
129    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
130        1 to "aa" instead of to an empty string. The bug affected repeated groups
131        that could potentially match an empty string.
132    
133    
134    Version 8.30 04-February-2012
135    -----------------------------
136    
137    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
138        name is defined in ctype.h.
139    
140    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
141        only in quite long subpatterns.
142    
143    3.  Removed the function pcre_info(), which has been obsolete and deprecated
144        since it was replaced by pcre_fullinfo() in February 2000.
145    
146    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
147        match a (*MARK), and the match failed at the start of the subject, a
148        reference to memory before the start of the subject could occur. This bug
149        was introduced by fix 17 of release 8.21.
150    
151    5.  A reference to an unset group with zero minimum repetition was giving
152        totally wrong answers (in non-JavaScript-compatibility mode). For example,
153        /(another)?(\1?)test/ matched against "hello world test". This bug was
154        introduced in release 8.13.
155    
156    6.  Add support for 16-bit character strings (a large amount of work involving
157        many changes and refactorings).
158    
159    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
160        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
161        from a file.
162    
163    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
164        rounding is not applied in this particular case).
165    
166    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
167        if they appear, or are escaped, in patterns.
168    
169    10. Get rid of a number of -Wunused-but-set-variable warnings.
170    
171    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
172        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
173        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
174        also returns the mark "x". This bug applied to capturing parentheses,
175        non-capturing parentheses, and atomic parentheses. It also applied to some
176        assertions.
177    
178    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
179        information out of configure.ac instead of relying on pcre.h.generic, which
180        is not stored in the repository.
181    
182    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
183        -lreadline.
184    
185    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
186    
187    15. Applied Graycode's patch to put the top-level frame on the stack rather
188        than the heap when not using the stack for recursion. This gives a
189        performance improvement in many cases when recursion is not deep.
190    
191    16. Experimental code added to "pcretest -C" to output the stack frame size.
192    
193    
194    Version 8.21 12-Dec-2011
195    ------------------------
196    
197    1.  Updating the JIT compiler.
198    
199    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
200        are added as well.
201    
202    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
203        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
204        calling _pcre_jit_exec. Some extra comments are added.
205    
206    4.  (*MARK) settings inside atomic groups that do not contain any capturing
207        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
208        was introduced by change 18 for 8.20.
209    
210    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
211        ECMA-262 standard.
212    
213    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
214        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
215        This bug was probably introduced by change 9 of 8.13.
216    
217    7.  While fixing 6 above, I noticed that a number of other items were being
218        incorrectly rejected as "not fixed length". This arose partly because newer
219        opcodes had not been added to the fixed-length checking code. I have (a)
220        corrected the bug and added tests for these items, and (b) arranged for an
221        error to occur if an unknown opcode is encountered while checking for fixed
222        length instead of just assuming "not fixed length". The items that were
223        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
224        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
225        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
226    
227    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
228        being incorrectly compiled and would have given unpredicatble results.
229    
230    9.  A possessively repeated subpattern with minimum repeat count greater than
231        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
232        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
233        the first (A) could occur when it should not.
234    
235    10. Add a cast and remove a redundant test from the code.
236    
237    11. JIT should use pcre_malloc/pcre_free for allocation.
238    
239    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
240        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
241        is anything other than /usr, -L is still shown).
242    
243    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
244    
245    14. Perl does not support \N without a following name in a [] class; PCRE now
246        also gives an error.
247    
248    15. If a forward reference was repeated with an upper limit of around 2000,
249        it caused the error "internal error: overran compiling workspace". The
250        maximum number of forward references (including repeats) was limited by the
251        internal workspace, and dependent on the LINK_SIZE. The code has been
252        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
253        the default depends on LINK_SIZE. There is a new upper limit (for safety)
254        of around 200,000 forward references. While doing this, I also speeded up
255        the filling in of repeated forward references.
256    
257    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
258        incorrectly expecting the subject to contain another "a" after the start.
259    
260    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
261        in the match, the SKIP should be ignored. This was not happening; instead
262        the SKIP was being treated as NOMATCH. For patterns such as
263        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
264        tested.
265    
266    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
267        now much more compatible with Perl, in particular in cases where the result
268        is a non-match for a non-anchored pattern. For example, if
269        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
270        "m", where previously it did not return a name. A side effect of this
271        change is that for partial matches, the last encountered mark name is
272        returned, as for non matches. A number of tests that were previously not
273        Perl-compatible have been moved into the Perl-compatible test files. The
274        refactoring has had the pleasing side effect of removing one argument from
275        the match() function, thus reducing its stack requirements.
276    
277    19. If the /S+ option was used in pcretest to study a pattern using JIT,
278        subsequent uses of /S (without +) incorrectly behaved like /S+.
279    
280    21. Retrieve executable code size support for the JIT compiler and fixing
281        some warnings.
282    
283    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
284        not work when the shorter character appeared right at the end of the
285        subject string.
286    
287    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
288        systems.
289    
290    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
291        output it when the /M option is used in pcretest.
292    
293    25. The CheckMan script was not being included in the distribution. Also, added
294        an explicit "perl" to run Perl scripts from the PrepareRelease script
295        because this is reportedly needed in Windows.
296    
297    26. If study data was being save in a file and studying had not found a set of
298        "starts with" bytes for the pattern, the data written to the file (though
299        never used) was taken from uninitialized memory and so caused valgrind to
300        complain.
301    
302    27. Updated RunTest.bat as provided by Sheri Pierce.
303    
304    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
305    
306    29. Computation of memory usage for the table of capturing group names was
307        giving an unnecessarily large value.
308    
309    
310    Version 8.20 21-Oct-2011
311    ------------------------
312    
313    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
314        a POSIX class. After further experiments with Perl, which convinced me that
315        Perl has bugs and confusions, a closing square bracket is no longer allowed
316        in a POSIX name. This bug also affected patterns with classes that started
317        with full stops.
318    
319    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
320        captured substring, but while checking the failing first alternative,
321        substring 1 is temporarily captured. If the output vector supplied to
322        pcre_exec() was not big enough for this capture, the yield of the function
323        was still zero ("insufficient space for captured substrings"). This cannot
324        be totally fixed without adding another stack variable, which seems a lot
325        of expense for a edge case. However, I have improved the situation in cases
326        such as /(a)(b)x|abc/ matched against "abc", where the return code
327        indicates that fewer than the maximum number of slots in the ovector have
328        been set.
329    
330    3.  Related to (2) above: when there are more back references in a pattern than
331        slots in the output vector, pcre_exec() uses temporary memory during
332        matching, and copies in the captures as far as possible afterwards. It was
333        using the entire output vector, but this conflicts with the specification
334        that only 2/3 is used for passing back captured substrings. Now it uses
335        only the first 2/3, for compatibility. This is, of course, another edge
336        case.
337    
338    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
339        main code base, and can be used by building with --enable-jit. When this is
340        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
341        runtime --no-jit option is given.
342    
343    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
344        ovector, the return from the function was zero, implying that there were
345        other matches that did not fit. The correct "exactly full" value is now
346        returned.
347    
348    6.  If a subpattern that was called recursively or as a subroutine contained
349        (*PRUNE) or any other control that caused it to give a non-standard return,
350        invalid errors such as "Error -26 (nested recursion at the same subject
351        position)" or even infinite loops could occur.
352    
353    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
354        computing the minimum length on reaching *ACCEPT, and so ended up with the
355        wrong value of 1 rather than 0. Further investigation indicates that
356        computing a minimum subject length in the presence of *ACCEPT is difficult
357        (think back references, subroutine calls), and so I have changed the code
358        so that no minimum is registered for a pattern that contains *ACCEPT.
359    
360    8.  If (*THEN) was present in the first (true) branch of a conditional group,
361        it was not handled as intended. [But see 16 below.]
362    
363    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
364        Sheri Pierce.
365    
366    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
367        the first byte in a match must be "a".
368    
369    11. Change 17 for 8.13 increased the recursion depth for patterns like
370        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
371        pattern contains any instances of (*THEN). If it does not, the old
372        optimizations are restored. It would be nice to do this on a per-group
373        basis, but at the moment that is not feasible.
374    
375    12. In some environments, the output of pcretest -C is CRLF terminated. This
376        broke RunTest's code that checks for the link size. A single white space
377        character after the value is now allowed for.
378    
379    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
380        For "fr", it uses the Windows-specific input and output files.
381    
382    14. If (*THEN) appeared in a group that was called recursively or as a
383        subroutine, it did not work as intended. [But see next item.]
384    
385    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
386        pattern fragments (but not containing any | characters). If A and B are
387        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
388        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
389        D. In other words, Perl considers parentheses that do not contain any |
390        characters to be part of a surrounding alternative, whereas PCRE was
391        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
392        differently. PCRE now behaves in the same way as Perl, except in the case
393        of subroutine/recursion calls such as (?1) which have in any case always
394        been different (but PCRE had them first :-).
395    
396    16. Related to 15 above: Perl does not treat the | in a conditional group as
397        creating alternatives. Such a group is treated in the same way as an
398        ordinary group without any | characters when processing (*THEN). PCRE has
399        been changed to match Perl's behaviour.
400    
401    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
402        RunGrepTest script failed.
403    
404    18. Change 22 for version 13 caused atomic groups to use more stack. This is
405        inevitable for groups that contain captures, but it can lead to a lot of
406        stack use in large patterns. The old behaviour has been restored for atomic
407        groups that do not contain any capturing parentheses.
408    
409    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
410        suppress the check for a minimum subject length at run time. (If it was
411        given to pcre_exec() or pcre_dfa_exec() it did work.)
412    
413    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
414        fail to work when decoding hex characters in data strings in EBCDIC
415        environments.
416    
417    21. It appears that in at least one Mac OS environment, the isxdigit() function
418        is implemented as a macro that evaluates to its argument more than once,
419        contravening the C 90 Standard (I haven't checked a later standard). There
420        was an instance in pcretest which caused it to go wrong when processing
421        \x{...} escapes in subject strings. The has been rewritten to avoid using
422        things like p++ in the argument of isxdigit().
423    
424    
425    Version 8.13 16-Aug-2011
426    ------------------------
427    
428    1.  The Unicode data tables have been updated to Unicode 6.0.0.
429    
430    2.  Two minor typos in pcre_internal.h have been fixed.
431    
432    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
433        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
434        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
435    
436    4.  There were a number of related bugs in the code for matching backrefences
437        caselessly in UTF-8 mode when codes for the characters concerned were
438        different numbers of bytes. For example, U+023A and U+2C65 are an upper
439        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
440        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
441        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
442        2-byte code at the end of the subject (it thought there wasn't enough data
443        left).
444    
445    5.  Comprehensive information about what went wrong is now returned by
446        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
447        as the output vector has at least 2 elements. The offset of the start of
448        the failing character and a reason code are placed in the vector.
449    
450    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
451        now returned is for the first byte of the failing character, instead of the
452        last byte inspected. This is an incompatible change, but I hope it is small
453        enough not to be a problem. It makes the returned offset consistent with
454        pcre_exec() and pcre_dfa_exec().
455    
456    7.  pcretest now gives a text phrase as well as the error number when
457        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
458        failure, the offset and reason code are output.
459    
460    8.  When \R was used with a maximizing quantifier it failed to skip backwards
461        over a \r\n pair if the subsequent match failed. Instead, it just skipped
462        back over a single character (\n). This seems wrong (because it treated the
463        two characters as a single entity when going forwards), conflicts with the
464        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
465        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
466        has been changed.
467    
468    9.  Some internal refactoring has changed the processing so that the handling
469        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
470        time (the PCRE_DOTALL option was changed this way some time ago: version
471        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
472        which was always a bit of a fudge. It also means that there is one less
473        argument for the match() function, which reduces its stack requirements
474        slightly. This change also fixes an incompatibility with Perl: the pattern
475        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
476    
477    10. More internal refactoring has drastically reduced the number of recursive
478        calls to match() for possessively repeated groups such as (abc)++ when
479        using pcre_exec().
480    
481    11. While implementing 10, a number of bugs in the handling of groups were
482        discovered and fixed:
483    
484        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
485        (a|)*(?1) gave a compile-time internal error.
486        ((a|)+)+  did not notice that the outer group could match an empty string.
487        (^a|^)+   was not marked as anchored.
488        (.*a|.*)+ was not marked as matching at start or after a newline.
489    
490    12. Yet more internal refactoring has removed another argument from the match()
491        function. Special calls to this function are now indicated by setting a
492        value in a variable in the "match data" data block.
493    
494    13. Be more explicit in pcre_study() instead of relying on "default" for
495        opcodes that mean there is no starting character; this means that when new
496        ones are added and accidentally left out of pcre_study(), testing should
497        pick them up.
498    
499    14. The -s option of pcretest has been documented for ages as being an old
500        synonym of -m (show memory usage). I have changed it to mean "force study
501        for every regex", that is, assume /S for every regex. This is similar to -i
502        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
503        using it. It makes it easier to run collections of tests with and without
504        study enabled, and thereby test pcre_study() more easily. All the standard
505        tests are now run with and without -s (but some patterns can be marked as
506        "never study" - see 20 below).
507    
508    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
509        restoration of the capturing data to the outer values was not happening
510        correctly.
511    
512    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
513        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
514        pattern had matched an empty string, and so incorrectly returned a no
515        match.
516    
517    17. There was optimizing code for the last branch of non-capturing parentheses,
518        and also for the obeyed branch of a conditional subexpression, which used
519        tail recursion to cut down on stack usage. Unfortunately, now that there is
520        the possibility of (*THEN) occurring in these branches, tail recursion is
521        no longer possible because the return has to be checked for (*THEN). These
522        two optimizations have therefore been removed. [But see 8.20/11 above.]
523    
524    18. If a pattern containing \R was studied, it was assumed that \R always
525        matched two bytes, thus causing the minimum subject length to be
526        incorrectly computed because \R can also match just one byte.
527    
528    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
529        was incorrectly computed.
530    
531    20. If /S is present twice on a test pattern in pcretest input, it now
532        *disables* studying, thereby overriding the use of -s on the command line
533        (see 14 above). This is necessary for one or two tests to keep the output
534        identical in both cases.
535    
536    21. When (*ACCEPT) was used in an assertion that matched an empty string and
537        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
538    
539    22. When an atomic group that contained a capturing parenthesis was
540        successfully matched, but the branch in which it appeared failed, the
541        capturing was not being forgotten if a higher numbered group was later
542        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
543        group 1 to "a", when in fact it should be unset. This applied to multi-
544        branched capturing and non-capturing groups, repeated or not, and also to
545        positive assertions (capturing in negative assertions does not happen
546        in PCRE) and also to nested atomic groups.
547    
548    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
549        subject after a captured substring, to make it easier to tell which of a
550        number of identical substrings has been captured.
551    
552    24. The way atomic groups are processed by pcre_exec() has been changed so that
553        if they are repeated, backtracking one repetition now resets captured
554        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
555        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
556        "aaa". Previously, it would have been "a". As part of this code
557        refactoring, the way recursive calls are handled has also been changed.
558    
559    25. If an assertion condition captured any substrings, they were not passed
560        back unless some other capturing happened later. For example, if
561        (?(?=(a))a) was matched against "a", no capturing was returned.
562    
563    26. When studying a pattern that contained subroutine calls or assertions,
564        the code for finding the minimum length of a possible match was handling
565        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
566        group 1 called group 2 while simultaneously a separate group 2 called group
567        1). A stack overflow occurred in this case. I have fixed this by limiting
568        the recursion depth to 10.
569    
570    27. Updated RunTest.bat in the distribution to the version supplied by Tom
571        Fortmann. This supports explicit test numbers on the command line, and has
572        argument validation and error reporting.
573    
574    28. An instance of \X with an unlimited repeat could fail if at any point the
575        first character it looked at was a mark character.
576    
577    29. Some minor code refactoring concerning Unicode properties and scripts
578        should reduce the stack requirement of match() slightly.
579    
580    30. Added the '=' option to pcretest to check the setting of unused capturing
581        slots at the end of the pattern, which are documented as being -1, but are
582        not included in the return count.
583    
584    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
585        compiled something random. Now it gives a compile-time error (as does
586        Perl).
587    
588    32. A *MARK encountered during the processing of a positive assertion is now
589        recorded and passed back (compatible with Perl).
590    
591    33. If --only-matching or --colour was set on a pcregrep call whose pattern
592        had alternative anchored branches, the search for a second match in a line
593        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
594        matched the line "0102" twice. The same bug affected patterns that started
595        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
596        twice.
597    
598    34. Previously, PCRE did not allow quantification of assertions. However, Perl
599        does, and because of capturing effects, quantifying parenthesized
600        assertions may at times be useful. Quantifiers are now allowed for
601        parenthesized assertions.
602    
603    35. A minor code tidy in pcre_compile() when checking options for \R usage.
604    
605    36. \g was being checked for fancy things in a character class, when it should
606        just be a literal "g".
607    
608    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
609        appearance of a nested POSIX class supersedes an apparent external class.
610        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
611        unescaped square brackets may also appear as part of class names. For
612        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
613        more like Perl. (But see 8.20/1 above.)
614    
615    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
616        was because it thought it was \N{name}, which is not supported).
617    
618    39. Add minix to OS list not supporting the -S option in pcretest.
619    
620    40. PCRE tries to detect cases of infinite recursion at compile time, but it
621        cannot analyze patterns in sufficient detail to catch mutual recursions
622        such as ((?1))((?2)). There is now a runtime test that gives an error if a
623        subgroup is called recursively as a subpattern for a second time at the
624        same position in the subject string. In previous releases this might have
625        been caught by the recursion limit, or it might have run out of stack.
626    
627    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
628        happen only once. PCRE was, however incorrectly giving a compile time error
629        "recursive call could loop indefinitely" because it cannot analyze the
630        pattern in sufficient detail. The compile time test no longer happens when
631        PCRE is compiling a conditional subpattern, but actual runaway loops are
632        now caught at runtime (see 40 above).
633    
634    42. It seems that Perl allows any characters other than a closing parenthesis
635        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
636        has been changed to be the same.
637    
638    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
639        as not to get warnings when autogen.sh is called. Also changed
640        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
641    
642    44. To help people who use pcregrep to scan files containing exceedingly long
643        lines, the following changes have been made:
644    
645        (a) The default value of the buffer size parameter has been increased from
646            8K to 20K. (The actual buffer used is three times this size.)
647    
648        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
649            PCRE is built.
650    
651        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
652            to be set at run time.
653    
654        (d) Numerical values in pcregrep options can be followed by K or M, for
655            example --buffer-size=50K.
656    
657        (e) If a line being scanned overflows pcregrep's buffer, an error is now
658            given and the return code is set to 2.
659    
660    45. Add a pointer to the latest mark to the callout data block.
661    
662    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
663        partial match of an empty string instead of no match. This was specific to
664        the use of ".".
665    
666    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
667        complete match instead of a partial match. This bug was dependent on both
668        the PCRE_UTF8 and PCRE_DOTALL options being set.
669    
670    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
671        starting byte set, because \b was not being ignored.
672    
673    
674    Version 8.12 15-Jan-2011
675    ------------------------
676    
677    1.  Fixed some typos in the markup of the man pages, and wrote a script that
678        checks for such things as part of the documentation building process.
679    
680    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
681        --match-limit and --recursion-limit options (added for 8.11). In
682        particular, this made one of the standard tests fail. (The integer value
683        went into the wrong half of a long int.)
684    
685    3.  If the --colour option was given to pcregrep with -v (invert match), it
686        did strange things, either producing crazy output, or crashing. It should,
687        of course, ignore a request for colour when reporting lines that do not
688        match.
689    
690    4.  Another pcregrep bug caused similar problems if --colour was specified with
691        -M (multiline) and the pattern match finished with a line ending.
692    
693    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
694        matched in multiline mode, the following line was shown as part of the
695        match. This seems wrong, so I have changed it.
696    
697    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
698        the check for further matches in the same line (so they could be coloured)
699        to overrun the end of the current line. If another match was found, it was
700        incorrectly shown (and then shown again when found in the next line).
701    
702    7.  If pcregrep was compiled under Windows, there was a reference to the
703        function pcregrep_exit() before it was defined. I am assuming this was
704        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
705        reported by a user. I've moved the definition above the reference.
706    
707    
708    Version 8.11 10-Dec-2010
709    ------------------------
710    
711    1.  (*THEN) was not working properly if there were untried alternatives prior
712        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
713        backtracked to try for "b" instead of moving to the next alternative branch
714        at the same level (in this case, to look for "c"). The Perl documentation
715        is clear that when (*THEN) is backtracked onto, it goes to the "next
716        alternative in the innermost enclosing group".
717    
718    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
719        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
720        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
721        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
722        (*THEN).
723    
724    3.  If \s appeared in a character class, it removed the VT character from
725        the class, even if it had been included by some previous item, for example
726        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
727        of \s, but is part of the POSIX "space" class.)
728    
729    4.  A partial match never returns an empty string (because you can always
730        match an empty string at the end of the subject); however the checking for
731        an empty string was starting at the "start of match" point. This has been
732        changed to the "earliest inspected character" point, because the returned
733        data for a partial match starts at this character. This means that, for
734        example, /(?<=abc)def/ gives a partial match for the subject "abc"
735        (previously it gave "no match").
736    
737    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
738        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
739        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
740        has an implication that the given string is incomplete (because a partial
741        match is preferred over a full match). For this reason, these items now
742        give a partial match in this situation. [Aside: previously, the one case
743        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
744        match rather than a full match, which was wrong by the old rules, but is
745        now correct.]
746    
747    6.  There was a bug in the handling of #-introduced comments, recognized when
748        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
749        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
750        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
751        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
752        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
753        places in pcre_compile().
754    
755    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
756        comments when looking ahead for named forward references to subpatterns,
757        the only newline sequence it recognized was NL. It now handles newlines
758        according to the set newline convention.
759    
760    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
761        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
762        cater for a lack of strerror(). These oversights have been fixed.
763    
764    9.  Added --match-limit and --recursion-limit to pcregrep.
765    
766    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
767    
768    11. When the -o option was used, pcregrep was setting a return code of 1, even
769        when matches were found, and --line-buffered was not being honoured.
770    
771    12. Added an optional parentheses number to the -o and --only-matching options
772        of pcregrep.
773    
774    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
775        can match an empty string. The code to do it in pcretest and pcredemo
776        needed fixing:
777    
778        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
779            only one byte after an empty string match just before CRLF (this case
780            just got forgotten; "any" and "anycrlf" were OK).
781    
782        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
783            mode when an empty string match preceded an ASCII character followed by
784            a non-ASCII character. (The code for advancing by one character rather
785            than one byte was nonsense.)
786    
787        (c) The pcredemo.c sample program did not have any code at all to handle
788            the cases when CRLF is a valid newline sequence.
789    
790    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
791        as a starting offset was within the subject string. There is now a new
792        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
793        negative or greater than the length of the string. In order to test this,
794        pcretest is extended to allow the setting of negative starting offsets.
795    
796    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
797        starting offset points to the beginning of a UTF-8 character was
798        unnecessarily clumsy. I tidied it up.
799    
800    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
801        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
802    
803    17. Nobody had reported that the --include_dir option, which was added in
804        release 7.7 should have been called --include-dir (hyphen, not underscore)
805        for compatibility with GNU grep. I have changed it to --include-dir, but
806        left --include_dir as an undocumented synonym, and the same for
807        --exclude-dir, though that is not available in GNU grep, at least as of
808        release 2.5.4.
809    
810    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
811        characters from a string of bytes) have been redefined so as not to use
812        loops, in order to improve performance in some environments. At the same
813        time, I abstracted some of the common code into auxiliary macros to save
814        repetition (this should not affect the compiled code).
815    
816    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
817        compile-time error is now given if \c is not followed by an ASCII
818        character, that is, a byte less than 128. (In EBCDIC mode, the code is
819        different, and any byte value is allowed.)
820    
821    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
822        START_OPTIMIZE option, which is now allowed at compile time - but just
823        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
824        to pcregrep and other applications that have no direct access to PCRE
825        options. The new /Y option in pcretest sets this option when calling
826        pcre_compile().
827    
828    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
829        back references. Groups containing recursive back references were forced to
830        be atomic by that change, but in the case of named groups, the amount of
831        memory required was incorrectly computed, leading to "Failed: internal
832        error: code overflow". This has been fixed.
833    
834    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
835        pcretest.c, to avoid build problems in some Borland environments.
836    
837    
838    Version 8.10 25-Jun-2010
839    ------------------------
840    
841    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
842        THEN.
843    
844    2.  (*ACCEPT) was not working when inside an atomic group.
845    
846    3.  Inside a character class, \B is treated as a literal by default, but
847        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
848        causes the error). The code is unchanged, but I tidied the documentation.
849    
850    4.  Inside a character class, PCRE always treated \R and \X as literals,
851        whereas Perl faults them if its -w option is set. I have changed PCRE so
852        that it faults them when PCRE_EXTRA is set.
853    
854    5.  Added support for \N, which always matches any character other than
855        newline. (It is the same as "." when PCRE_DOTALL is not set.)
856    
857    6.  When compiling pcregrep with newer versions of gcc which may have
858        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
859        declared with attribute warn_unused_result" were given. Just casting the
860        result to (void) does not stop the warnings; a more elaborate fudge is
861        needed. I've used a macro to implement this.
862    
863    7.  Minor change to pcretest.c to avoid a compiler warning.
864    
865    8.  Added four artifical Unicode properties to help with an option to make
866        \s etc use properties (see next item). The new properties are: Xan
867        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
868    
869    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
870        use Unicode properties. (*UCP) at the start of a pattern can be used to set
871        this option. Modified pcretest to add /W to test this facility. Added
872        REG_UCP to make it available via the POSIX interface.
873    
874    10. Added --line-buffered to pcregrep.
875    
876    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
877        studied, and the match started with a letter with a code point greater than
878        127 whose first byte was different to the first byte of the other case of
879        the letter, the other case of this starting letter was not recognized
880        (#976).
881    
882    12. If a pattern that was studied started with a repeated Unicode property
883        test, for example, \p{Nd}+, there was the theoretical possibility of
884        setting up an incorrect bitmap of starting bytes, but fortunately it could
885        not have actually happened in practice until change 8 above was made (it
886        added property types that matched character-matching opcodes).
887    
888    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
889        possible starting bytes for non-anchored patterns.
890    
891    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
892        \R, and also a number of cases that involve Unicode properties, both
893        explicit and implicit when PCRE_UCP is set.
894    
895    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
896        input, it could crash or give wrong results if characters with values
897        greater than 0xc0 were present in the subject string. (Detail: it assumed
898        UTF-8 input when processing these items.)
899    
900    16. Added a lot of (int) casts to avoid compiler warnings in systems where
901        size_t is 64-bit (#991).
902    
903    17. Added a check for running out of memory when PCRE is compiled with
904        --disable-stack-for-recursion (#990).
905    
906    18. If the last data line in a file for pcretest does not have a newline on
907        the end, a newline was missing in the output.
908    
909    19. The default pcre_chartables.c file recognizes only ASCII characters (values
910        less than 128) in its various bitmaps. However, there is a facility for
911        generating tables according to the current locale when PCRE is compiled. It
912        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
913        characters, are recognized by isspace() and therefore were getting set in
914        these tables, and indeed these tables seem to approximate to ISO 8859. This
915        caused a problem in UTF-8 mode when pcre_study() was used to create a list
916        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
917        which of course cannot start UTF-8 characters. I have changed the code so
918        that only real ASCII characters (less than 128) and the correct starting
919        bytes for UTF-8 encodings are set for characters greater than 127 when in
920        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
921        altogether.)
922    
923    20. Added the /T option to pcretest so as to be able to run tests with non-
924        standard character tables, thus making it possible to include the tests
925        used for 19 above in the standard set of tests.
926    
927    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
928        reference to a subpattern the other side of a comment that contains an
929        opening parenthesis caused either an internal compiling error, or a
930        reference to the wrong subpattern.
931    
932    
933    Version 8.02 19-Mar-2010
934  ------------------------  ------------------------
935    
936  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
937    
938    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
939        configured.
940    
941    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
942        original author of that file, following a query about its status.
943    
944    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
945        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
946    
947    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
948        quantifier applied to a forward-referencing subroutine call, could compile
949        incorrect code or give the error "internal error: previously-checked
950        referenced subpattern not found".
951    
952    6.  Both MS Visual Studio and Symbian OS have problems with initializing
953        variables to point to external functions. For these systems, therefore,
954        pcre_malloc etc. are now initialized to local functions that call the
955        relevant global functions.
956    
957    7.  There were two entries missing in the vectors called coptable and poptable
958        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
959        I've fixed the data, and added a kludgy way of testing at compile time that
960        the lengths are correct (equal to the number of opcodes).
961    
962    8.  Following on from 7, I added a similar kludge to check the length of the
963        eint vector in pcreposix.c.
964    
965    9.  Error texts for pcre_compile() are held as one long string to avoid too
966        much relocation at load time. To find a text, the string is searched,
967        counting zeros. There was no check for running off the end of the string,
968        which could happen if a new error number was added without updating the
969        string.
970    
971    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
972    
973    11. \K was not working if it appeared in an atomic group or in a group that
974        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
975        \K is "not well defined" if used in an assertion. PCRE now accepts it if
976        the assertion is positive, but not if it is negative.
977    
978    12. Change 11 fortuitously reduced the size of the stack frame used in the
979        "match()" function of pcre_exec.c by one pointer. Forthcoming
980        implementation of support for (*MARK) will need an extra pointer on the
981        stack; I have reserved it now, so that the stack frame size does not
982        decrease.
983    
984    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
985        item in branch that calls a recursion is a subroutine call - as in the
986        second branch in the above example - was incorrectly given the compile-
987        time error "recursive call could loop indefinitely" because pcre_compile()
988        was not correctly checking the subroutine for matching a non-empty string.
989    
990    14. The checks for overrunning compiling workspace could trigger after an
991        overrun had occurred. This is a "should never occur" error, but it can be
992        triggered by pathological patterns such as hundreds of nested parentheses.
993        The checks now trigger 100 bytes before the end of the workspace.
994    
995    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
996    
997    
998  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
999  ------------------------  ------------------------

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