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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.01 11-Dec-09  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    
16    Version 8.31 06-July-2012
17    -------------------------
18    
19    1.  Fixing a wrong JIT test case and some compiler warnings.
20    
21    2.  Removed a bashism from the RunTest script.
22    
23    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
24        to unsigned type, result still unsigned" that was given by an MS compiler
25        on encountering the code "-sizeof(xxx)".
26    
27    4.  Partial matching support is added to the JIT compiler.
28    
29    5.  Fixed several bugs concerned with partial matching of items that consist
30        of more than one character:
31    
32        (a) /^(..)\1/ did not partially match "aba" because checking references was
33            done on an "all or nothing" basis. This also applied to repeated
34            references.
35    
36        (b) \R did not give a hard partial match if \r was found at the end of the
37            subject.
38    
39        (c) \X did not give a hard partial match after matching one or more
40            characters at the end of the subject.
41    
42        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
43            a partial match for the string "\r".
44    
45        (e) When newline was set to CRLF, the metacharacter "." did not recognize
46            a partial match for a CR character at the end of the subject string.
47    
48    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
49        running pcretest, the text "(JIT)" added to the output whenever JIT is
50        actually used to run the match.
51    
52    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
53        or /S+[+] with a digit between 1 and 7.
54    
55    8.  OP_NOT now supports any UTF character not just single-byte ones.
56    
57    9.  (*MARK) control verb is now supported by the JIT compiler.
58    
59    10. The command "./RunTest list" lists the available tests without actually
60        running any of them. (Because I keep forgetting what they all are.)
61    
62    11. Add PCRE_INFO_MAXLOOKBEHIND.
63    
64    12. Applied a (slightly modified) user-supplied patch that improves performance
65        when the heap is used for recursion (compiled with --disable-stack-for-
66        recursion). Instead of malloc and free for each heap frame each time a
67        logical recursion happens, frames are retained on a chain and re-used where
68        possible. This sometimes gives as much as 30% improvement.
69    
70    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
71        call.
72    
73    14. As documented, (*COMMIT) is now confined to within a positive assertion.
74    
75    15. It is now possible to link pcretest with libedit as an alternative to
76        libreadline.
77    
78    16. (*COMMIT) control verb is now supported by the JIT compiler.
79    
80    17. The Unicode data tables have been updated to Unicode 6.1.0.
81    
82    18. Added --file-list option to pcregrep.
83    
84    19. Added binary file support to pcregrep, including the -a, --binary-files,
85        -I, and --text options.
86    
87    20. The madvise function is renamed for posix_madvise for QNX compatibility
88        reasons. Fixed by Giuseppe D'Angelo.
89    
90    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
91    
92    22. Changed the option for creating symbolic links for 16-bit man pages from
93        -s to -sf so that re-installing does not cause issues.
94    
95    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
96    
97    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
98        matches in certain environments (the workspace was not being correctly
99        retained). Also added to pcre_dfa_exec() a simple plausibility check on
100        some of the workspace data at the beginning of a restart.
101    
102    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
103        was not doing so when it should - probably a typo introduced by SVN 528
104        (change 8.10/14).
105    
106    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
107        \w+ when the character tables indicated that \x{c4} was a word character.
108        There were several related cases, all because the tests for doing a table
109        lookup were testing for characters less than 127 instead of 255.
110    
111    27. If a pattern contains capturing parentheses that are not used in a match,
112        their slots in the ovector are set to -1. For those that are higher than
113        any matched groups, this happens at the end of processing. In the case when
114        there were back references that the ovector was too small to contain
115        (causing temporary malloc'd memory to be used during matching), and the
116        highest capturing number was not used, memory off the end of the ovector
117        was incorrectly being set to -1. (It was using the size of the temporary
118        memory instead of the true size.)
119    
120    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
121        ovector size, it uses memory at the end of the block that it has got.
122    
123    29. Check for an overlong MARK name and give an error at compile time. The
124        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
125    
126    30. JIT compiler update.
127    
128    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
129        Rill for the patch.
130    
131    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
132    
133    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
134    
135    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
136        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
137        was enabled.
138    
139    35. Improve JIT code generation for greedy plus quantifier.
140    
141    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
142        1 to "aa" instead of to an empty string. The bug affected repeated groups
143        that could potentially match an empty string.
144    
145    37. Optimizing single character iterators in JIT.
146    
147    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
148        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
149        codepoints that are too big for the mode are faulted, and in a UTF mode,
150        disallowed codepoints are also faulted.
151    
152    39. If PCRE was compiled with UTF support, in three places in the DFA
153        matcher there was code that should only have been obeyed in UTF mode, but
154        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
155        processing when bytes with values greater than 127 were present. In 16-bit
156        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
157        both cases the values are those that cannot be the first data item in a UTF
158        character. The three items that might have provoked this were recursions,
159        possessively repeated groups, and atomic groups.
160    
161    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
162        and pcregrep, because some OS require shared objects to be explicitly
163        passed to ld, causing the link step to fail if they are not.
164    
165    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
166        mode, patterns that started with \h* or \R* might be incorrectly matched.
167    
168    
169    Version 8.30 04-February-2012
170    -----------------------------
171    
172    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
173        name is defined in ctype.h.
174    
175    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
176        only in quite long subpatterns.
177    
178    3.  Removed the function pcre_info(), which has been obsolete and deprecated
179        since it was replaced by pcre_fullinfo() in February 2000.
180    
181    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
182        match a (*MARK), and the match failed at the start of the subject, a
183        reference to memory before the start of the subject could occur. This bug
184        was introduced by fix 17 of release 8.21.
185    
186    5.  A reference to an unset group with zero minimum repetition was giving
187        totally wrong answers (in non-JavaScript-compatibility mode). For example,
188        /(another)?(\1?)test/ matched against "hello world test". This bug was
189        introduced in release 8.13.
190    
191    6.  Add support for 16-bit character strings (a large amount of work involving
192        many changes and refactorings).
193    
194    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
195        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
196        from a file.
197    
198    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
199        rounding is not applied in this particular case).
200    
201    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
202        if they appear, or are escaped, in patterns.
203    
204    10. Get rid of a number of -Wunused-but-set-variable warnings.
205    
206    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
207        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
208        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
209        also returns the mark "x". This bug applied to capturing parentheses,
210        non-capturing parentheses, and atomic parentheses. It also applied to some
211        assertions.
212    
213    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
214        information out of configure.ac instead of relying on pcre.h.generic, which
215        is not stored in the repository.
216    
217    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
218        -lreadline.
219    
220    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
221    
222    15. Applied Graycode's patch to put the top-level frame on the stack rather
223        than the heap when not using the stack for recursion. This gives a
224        performance improvement in many cases when recursion is not deep.
225    
226    16. Experimental code added to "pcretest -C" to output the stack frame size.
227    
228    
229    Version 8.21 12-Dec-2011
230    ------------------------
231    
232    1.  Updating the JIT compiler.
233    
234    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
235        are added as well.
236    
237    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
238        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
239        calling _pcre_jit_exec. Some extra comments are added.
240    
241    4.  (*MARK) settings inside atomic groups that do not contain any capturing
242        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
243        was introduced by change 18 for 8.20.
244    
245    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
246        ECMA-262 standard.
247    
248    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
249        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
250        This bug was probably introduced by change 9 of 8.13.
251    
252    7.  While fixing 6 above, I noticed that a number of other items were being
253        incorrectly rejected as "not fixed length". This arose partly because newer
254        opcodes had not been added to the fixed-length checking code. I have (a)
255        corrected the bug and added tests for these items, and (b) arranged for an
256        error to occur if an unknown opcode is encountered while checking for fixed
257        length instead of just assuming "not fixed length". The items that were
258        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
259        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
260        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
261    
262    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
263        being incorrectly compiled and would have given unpredicatble results.
264    
265    9.  A possessively repeated subpattern with minimum repeat count greater than
266        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
267        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
268        the first (A) could occur when it should not.
269    
270    10. Add a cast and remove a redundant test from the code.
271    
272    11. JIT should use pcre_malloc/pcre_free for allocation.
273    
274    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
275        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
276        is anything other than /usr, -L is still shown).
277    
278    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
279    
280    14. Perl does not support \N without a following name in a [] class; PCRE now
281        also gives an error.
282    
283    15. If a forward reference was repeated with an upper limit of around 2000,
284        it caused the error "internal error: overran compiling workspace". The
285        maximum number of forward references (including repeats) was limited by the
286        internal workspace, and dependent on the LINK_SIZE. The code has been
287        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
288        the default depends on LINK_SIZE. There is a new upper limit (for safety)
289        of around 200,000 forward references. While doing this, I also speeded up
290        the filling in of repeated forward references.
291    
292    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
293        incorrectly expecting the subject to contain another "a" after the start.
294    
295    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
296        in the match, the SKIP should be ignored. This was not happening; instead
297        the SKIP was being treated as NOMATCH. For patterns such as
298        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
299        tested.
300    
301    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
302        now much more compatible with Perl, in particular in cases where the result
303        is a non-match for a non-anchored pattern. For example, if
304        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
305        "m", where previously it did not return a name. A side effect of this
306        change is that for partial matches, the last encountered mark name is
307        returned, as for non matches. A number of tests that were previously not
308        Perl-compatible have been moved into the Perl-compatible test files. The
309        refactoring has had the pleasing side effect of removing one argument from
310        the match() function, thus reducing its stack requirements.
311    
312    19. If the /S+ option was used in pcretest to study a pattern using JIT,
313        subsequent uses of /S (without +) incorrectly behaved like /S+.
314    
315    21. Retrieve executable code size support for the JIT compiler and fixing
316        some warnings.
317    
318    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
319        not work when the shorter character appeared right at the end of the
320        subject string.
321    
322    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
323        systems.
324    
325    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
326        output it when the /M option is used in pcretest.
327    
328    25. The CheckMan script was not being included in the distribution. Also, added
329        an explicit "perl" to run Perl scripts from the PrepareRelease script
330        because this is reportedly needed in Windows.
331    
332    26. If study data was being save in a file and studying had not found a set of
333        "starts with" bytes for the pattern, the data written to the file (though
334        never used) was taken from uninitialized memory and so caused valgrind to
335        complain.
336    
337    27. Updated RunTest.bat as provided by Sheri Pierce.
338    
339    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
340    
341    29. Computation of memory usage for the table of capturing group names was
342        giving an unnecessarily large value.
343    
344    
345    Version 8.20 21-Oct-2011
346    ------------------------
347    
348    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
349        a POSIX class. After further experiments with Perl, which convinced me that
350        Perl has bugs and confusions, a closing square bracket is no longer allowed
351        in a POSIX name. This bug also affected patterns with classes that started
352        with full stops.
353    
354    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
355        captured substring, but while checking the failing first alternative,
356        substring 1 is temporarily captured. If the output vector supplied to
357        pcre_exec() was not big enough for this capture, the yield of the function
358        was still zero ("insufficient space for captured substrings"). This cannot
359        be totally fixed without adding another stack variable, which seems a lot
360        of expense for a edge case. However, I have improved the situation in cases
361        such as /(a)(b)x|abc/ matched against "abc", where the return code
362        indicates that fewer than the maximum number of slots in the ovector have
363        been set.
364    
365    3.  Related to (2) above: when there are more back references in a pattern than
366        slots in the output vector, pcre_exec() uses temporary memory during
367        matching, and copies in the captures as far as possible afterwards. It was
368        using the entire output vector, but this conflicts with the specification
369        that only 2/3 is used for passing back captured substrings. Now it uses
370        only the first 2/3, for compatibility. This is, of course, another edge
371        case.
372    
373    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
374        main code base, and can be used by building with --enable-jit. When this is
375        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
376        runtime --no-jit option is given.
377    
378    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
379        ovector, the return from the function was zero, implying that there were
380        other matches that did not fit. The correct "exactly full" value is now
381        returned.
382    
383    6.  If a subpattern that was called recursively or as a subroutine contained
384        (*PRUNE) or any other control that caused it to give a non-standard return,
385        invalid errors such as "Error -26 (nested recursion at the same subject
386        position)" or even infinite loops could occur.
387    
388    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
389        computing the minimum length on reaching *ACCEPT, and so ended up with the
390        wrong value of 1 rather than 0. Further investigation indicates that
391        computing a minimum subject length in the presence of *ACCEPT is difficult
392        (think back references, subroutine calls), and so I have changed the code
393        so that no minimum is registered for a pattern that contains *ACCEPT.
394    
395    8.  If (*THEN) was present in the first (true) branch of a conditional group,
396        it was not handled as intended. [But see 16 below.]
397    
398    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
399        Sheri Pierce.
400    
401    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
402        the first byte in a match must be "a".
403    
404    11. Change 17 for 8.13 increased the recursion depth for patterns like
405        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
406        pattern contains any instances of (*THEN). If it does not, the old
407        optimizations are restored. It would be nice to do this on a per-group
408        basis, but at the moment that is not feasible.
409    
410    12. In some environments, the output of pcretest -C is CRLF terminated. This
411        broke RunTest's code that checks for the link size. A single white space
412        character after the value is now allowed for.
413    
414    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
415        For "fr", it uses the Windows-specific input and output files.
416    
417    14. If (*THEN) appeared in a group that was called recursively or as a
418        subroutine, it did not work as intended. [But see next item.]
419    
420    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
421        pattern fragments (but not containing any | characters). If A and B are
422        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
423        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
424        D. In other words, Perl considers parentheses that do not contain any |
425        characters to be part of a surrounding alternative, whereas PCRE was
426        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
427        differently. PCRE now behaves in the same way as Perl, except in the case
428        of subroutine/recursion calls such as (?1) which have in any case always
429        been different (but PCRE had them first :-).
430    
431    16. Related to 15 above: Perl does not treat the | in a conditional group as
432        creating alternatives. Such a group is treated in the same way as an
433        ordinary group without any | characters when processing (*THEN). PCRE has
434        been changed to match Perl's behaviour.
435    
436    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
437        RunGrepTest script failed.
438    
439    18. Change 22 for version 13 caused atomic groups to use more stack. This is
440        inevitable for groups that contain captures, but it can lead to a lot of
441        stack use in large patterns. The old behaviour has been restored for atomic
442        groups that do not contain any capturing parentheses.
443    
444    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
445        suppress the check for a minimum subject length at run time. (If it was
446        given to pcre_exec() or pcre_dfa_exec() it did work.)
447    
448    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
449        fail to work when decoding hex characters in data strings in EBCDIC
450        environments.
451    
452    21. It appears that in at least one Mac OS environment, the isxdigit() function
453        is implemented as a macro that evaluates to its argument more than once,
454        contravening the C 90 Standard (I haven't checked a later standard). There
455        was an instance in pcretest which caused it to go wrong when processing
456        \x{...} escapes in subject strings. The has been rewritten to avoid using
457        things like p++ in the argument of isxdigit().
458    
459    
460    Version 8.13 16-Aug-2011
461    ------------------------
462    
463    1.  The Unicode data tables have been updated to Unicode 6.0.0.
464    
465    2.  Two minor typos in pcre_internal.h have been fixed.
466    
467    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
468        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
469        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
470    
471    4.  There were a number of related bugs in the code for matching backrefences
472        caselessly in UTF-8 mode when codes for the characters concerned were
473        different numbers of bytes. For example, U+023A and U+2C65 are an upper
474        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
475        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
476        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
477        2-byte code at the end of the subject (it thought there wasn't enough data
478        left).
479    
480    5.  Comprehensive information about what went wrong is now returned by
481        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
482        as the output vector has at least 2 elements. The offset of the start of
483        the failing character and a reason code are placed in the vector.
484    
485    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
486        now returned is for the first byte of the failing character, instead of the
487        last byte inspected. This is an incompatible change, but I hope it is small
488        enough not to be a problem. It makes the returned offset consistent with
489        pcre_exec() and pcre_dfa_exec().
490    
491    7.  pcretest now gives a text phrase as well as the error number when
492        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
493        failure, the offset and reason code are output.
494    
495    8.  When \R was used with a maximizing quantifier it failed to skip backwards
496        over a \r\n pair if the subsequent match failed. Instead, it just skipped
497        back over a single character (\n). This seems wrong (because it treated the
498        two characters as a single entity when going forwards), conflicts with the
499        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
500        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
501        has been changed.
502    
503    9.  Some internal refactoring has changed the processing so that the handling
504        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
505        time (the PCRE_DOTALL option was changed this way some time ago: version
506        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
507        which was always a bit of a fudge. It also means that there is one less
508        argument for the match() function, which reduces its stack requirements
509        slightly. This change also fixes an incompatibility with Perl: the pattern
510        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
511    
512    10. More internal refactoring has drastically reduced the number of recursive
513        calls to match() for possessively repeated groups such as (abc)++ when
514        using pcre_exec().
515    
516    11. While implementing 10, a number of bugs in the handling of groups were
517        discovered and fixed:
518    
519        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
520        (a|)*(?1) gave a compile-time internal error.
521        ((a|)+)+  did not notice that the outer group could match an empty string.
522        (^a|^)+   was not marked as anchored.
523        (.*a|.*)+ was not marked as matching at start or after a newline.
524    
525    12. Yet more internal refactoring has removed another argument from the match()
526        function. Special calls to this function are now indicated by setting a
527        value in a variable in the "match data" data block.
528    
529    13. Be more explicit in pcre_study() instead of relying on "default" for
530        opcodes that mean there is no starting character; this means that when new
531        ones are added and accidentally left out of pcre_study(), testing should
532        pick them up.
533    
534    14. The -s option of pcretest has been documented for ages as being an old
535        synonym of -m (show memory usage). I have changed it to mean "force study
536        for every regex", that is, assume /S for every regex. This is similar to -i
537        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
538        using it. It makes it easier to run collections of tests with and without
539        study enabled, and thereby test pcre_study() more easily. All the standard
540        tests are now run with and without -s (but some patterns can be marked as
541        "never study" - see 20 below).
542    
543    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
544        restoration of the capturing data to the outer values was not happening
545        correctly.
546    
547    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
548        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
549        pattern had matched an empty string, and so incorrectly returned a no
550        match.
551    
552    17. There was optimizing code for the last branch of non-capturing parentheses,
553        and also for the obeyed branch of a conditional subexpression, which used
554        tail recursion to cut down on stack usage. Unfortunately, now that there is
555        the possibility of (*THEN) occurring in these branches, tail recursion is
556        no longer possible because the return has to be checked for (*THEN). These
557        two optimizations have therefore been removed. [But see 8.20/11 above.]
558    
559    18. If a pattern containing \R was studied, it was assumed that \R always
560        matched two bytes, thus causing the minimum subject length to be
561        incorrectly computed because \R can also match just one byte.
562    
563    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
564        was incorrectly computed.
565    
566    20. If /S is present twice on a test pattern in pcretest input, it now
567        *disables* studying, thereby overriding the use of -s on the command line
568        (see 14 above). This is necessary for one or two tests to keep the output
569        identical in both cases.
570    
571    21. When (*ACCEPT) was used in an assertion that matched an empty string and
572        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
573    
574    22. When an atomic group that contained a capturing parenthesis was
575        successfully matched, but the branch in which it appeared failed, the
576        capturing was not being forgotten if a higher numbered group was later
577        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
578        group 1 to "a", when in fact it should be unset. This applied to multi-
579        branched capturing and non-capturing groups, repeated or not, and also to
580        positive assertions (capturing in negative assertions does not happen
581        in PCRE) and also to nested atomic groups.
582    
583    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
584        subject after a captured substring, to make it easier to tell which of a
585        number of identical substrings has been captured.
586    
587    24. The way atomic groups are processed by pcre_exec() has been changed so that
588        if they are repeated, backtracking one repetition now resets captured
589        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
590        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
591        "aaa". Previously, it would have been "a". As part of this code
592        refactoring, the way recursive calls are handled has also been changed.
593    
594    25. If an assertion condition captured any substrings, they were not passed
595        back unless some other capturing happened later. For example, if
596        (?(?=(a))a) was matched against "a", no capturing was returned.
597    
598    26. When studying a pattern that contained subroutine calls or assertions,
599        the code for finding the minimum length of a possible match was handling
600        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
601        group 1 called group 2 while simultaneously a separate group 2 called group
602        1). A stack overflow occurred in this case. I have fixed this by limiting
603        the recursion depth to 10.
604    
605    27. Updated RunTest.bat in the distribution to the version supplied by Tom
606        Fortmann. This supports explicit test numbers on the command line, and has
607        argument validation and error reporting.
608    
609    28. An instance of \X with an unlimited repeat could fail if at any point the
610        first character it looked at was a mark character.
611    
612    29. Some minor code refactoring concerning Unicode properties and scripts
613        should reduce the stack requirement of match() slightly.
614    
615    30. Added the '=' option to pcretest to check the setting of unused capturing
616        slots at the end of the pattern, which are documented as being -1, but are
617        not included in the return count.
618    
619    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
620        compiled something random. Now it gives a compile-time error (as does
621        Perl).
622    
623    32. A *MARK encountered during the processing of a positive assertion is now
624        recorded and passed back (compatible with Perl).
625    
626    33. If --only-matching or --colour was set on a pcregrep call whose pattern
627        had alternative anchored branches, the search for a second match in a line
628        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
629        matched the line "0102" twice. The same bug affected patterns that started
630        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
631        twice.
632    
633    34. Previously, PCRE did not allow quantification of assertions. However, Perl
634        does, and because of capturing effects, quantifying parenthesized
635        assertions may at times be useful. Quantifiers are now allowed for
636        parenthesized assertions.
637    
638    35. A minor code tidy in pcre_compile() when checking options for \R usage.
639    
640    36. \g was being checked for fancy things in a character class, when it should
641        just be a literal "g".
642    
643    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
644        appearance of a nested POSIX class supersedes an apparent external class.
645        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
646        unescaped square brackets may also appear as part of class names. For
647        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
648        more like Perl. (But see 8.20/1 above.)
649    
650    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
651        was because it thought it was \N{name}, which is not supported).
652    
653    39. Add minix to OS list not supporting the -S option in pcretest.
654    
655    40. PCRE tries to detect cases of infinite recursion at compile time, but it
656        cannot analyze patterns in sufficient detail to catch mutual recursions
657        such as ((?1))((?2)). There is now a runtime test that gives an error if a
658        subgroup is called recursively as a subpattern for a second time at the
659        same position in the subject string. In previous releases this might have
660        been caught by the recursion limit, or it might have run out of stack.
661    
662    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
663        happen only once. PCRE was, however incorrectly giving a compile time error
664        "recursive call could loop indefinitely" because it cannot analyze the
665        pattern in sufficient detail. The compile time test no longer happens when
666        PCRE is compiling a conditional subpattern, but actual runaway loops are
667        now caught at runtime (see 40 above).
668    
669    42. It seems that Perl allows any characters other than a closing parenthesis
670        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
671        has been changed to be the same.
672    
673    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
674        as not to get warnings when autogen.sh is called. Also changed
675        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
676    
677    44. To help people who use pcregrep to scan files containing exceedingly long
678        lines, the following changes have been made:
679    
680        (a) The default value of the buffer size parameter has been increased from
681            8K to 20K. (The actual buffer used is three times this size.)
682    
683        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
684            PCRE is built.
685    
686        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
687            to be set at run time.
688    
689        (d) Numerical values in pcregrep options can be followed by K or M, for
690            example --buffer-size=50K.
691    
692        (e) If a line being scanned overflows pcregrep's buffer, an error is now
693            given and the return code is set to 2.
694    
695    45. Add a pointer to the latest mark to the callout data block.
696    
697    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
698        partial match of an empty string instead of no match. This was specific to
699        the use of ".".
700    
701    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
702        complete match instead of a partial match. This bug was dependent on both
703        the PCRE_UTF8 and PCRE_DOTALL options being set.
704    
705    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
706        starting byte set, because \b was not being ignored.
707    
708    
709    Version 8.12 15-Jan-2011
710    ------------------------
711    
712    1.  Fixed some typos in the markup of the man pages, and wrote a script that
713        checks for such things as part of the documentation building process.
714    
715    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
716        --match-limit and --recursion-limit options (added for 8.11). In
717        particular, this made one of the standard tests fail. (The integer value
718        went into the wrong half of a long int.)
719    
720    3.  If the --colour option was given to pcregrep with -v (invert match), it
721        did strange things, either producing crazy output, or crashing. It should,
722        of course, ignore a request for colour when reporting lines that do not
723        match.
724    
725    4.  Another pcregrep bug caused similar problems if --colour was specified with
726        -M (multiline) and the pattern match finished with a line ending.
727    
728    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
729        matched in multiline mode, the following line was shown as part of the
730        match. This seems wrong, so I have changed it.
731    
732    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
733        the check for further matches in the same line (so they could be coloured)
734        to overrun the end of the current line. If another match was found, it was
735        incorrectly shown (and then shown again when found in the next line).
736    
737    7.  If pcregrep was compiled under Windows, there was a reference to the
738        function pcregrep_exit() before it was defined. I am assuming this was
739        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
740        reported by a user. I've moved the definition above the reference.
741    
742    
743    Version 8.11 10-Dec-2010
744    ------------------------
745    
746    1.  (*THEN) was not working properly if there were untried alternatives prior
747        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
748        backtracked to try for "b" instead of moving to the next alternative branch
749        at the same level (in this case, to look for "c"). The Perl documentation
750        is clear that when (*THEN) is backtracked onto, it goes to the "next
751        alternative in the innermost enclosing group".
752    
753    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
754        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
755        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
756        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
757        (*THEN).
758    
759    3.  If \s appeared in a character class, it removed the VT character from
760        the class, even if it had been included by some previous item, for example
761        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
762        of \s, but is part of the POSIX "space" class.)
763    
764    4.  A partial match never returns an empty string (because you can always
765        match an empty string at the end of the subject); however the checking for
766        an empty string was starting at the "start of match" point. This has been
767        changed to the "earliest inspected character" point, because the returned
768        data for a partial match starts at this character. This means that, for
769        example, /(?<=abc)def/ gives a partial match for the subject "abc"
770        (previously it gave "no match").
771    
772    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
773        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
774        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
775        has an implication that the given string is incomplete (because a partial
776        match is preferred over a full match). For this reason, these items now
777        give a partial match in this situation. [Aside: previously, the one case
778        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
779        match rather than a full match, which was wrong by the old rules, but is
780        now correct.]
781    
782    6.  There was a bug in the handling of #-introduced comments, recognized when
783        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
784        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
785        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
786        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
787        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
788        places in pcre_compile().
789    
790    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
791        comments when looking ahead for named forward references to subpatterns,
792        the only newline sequence it recognized was NL. It now handles newlines
793        according to the set newline convention.
794    
795    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
796        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
797        cater for a lack of strerror(). These oversights have been fixed.
798    
799    9.  Added --match-limit and --recursion-limit to pcregrep.
800    
801    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
802    
803    11. When the -o option was used, pcregrep was setting a return code of 1, even
804        when matches were found, and --line-buffered was not being honoured.
805    
806    12. Added an optional parentheses number to the -o and --only-matching options
807        of pcregrep.
808    
809    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
810        can match an empty string. The code to do it in pcretest and pcredemo
811        needed fixing:
812    
813        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
814            only one byte after an empty string match just before CRLF (this case
815            just got forgotten; "any" and "anycrlf" were OK).
816    
817        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
818            mode when an empty string match preceded an ASCII character followed by
819            a non-ASCII character. (The code for advancing by one character rather
820            than one byte was nonsense.)
821    
822        (c) The pcredemo.c sample program did not have any code at all to handle
823            the cases when CRLF is a valid newline sequence.
824    
825    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
826        as a starting offset was within the subject string. There is now a new
827        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
828        negative or greater than the length of the string. In order to test this,
829        pcretest is extended to allow the setting of negative starting offsets.
830    
831    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
832        starting offset points to the beginning of a UTF-8 character was
833        unnecessarily clumsy. I tidied it up.
834    
835    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
836        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
837    
838    17. Nobody had reported that the --include_dir option, which was added in
839        release 7.7 should have been called --include-dir (hyphen, not underscore)
840        for compatibility with GNU grep. I have changed it to --include-dir, but
841        left --include_dir as an undocumented synonym, and the same for
842        --exclude-dir, though that is not available in GNU grep, at least as of
843        release 2.5.4.
844    
845    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
846        characters from a string of bytes) have been redefined so as not to use
847        loops, in order to improve performance in some environments. At the same
848        time, I abstracted some of the common code into auxiliary macros to save
849        repetition (this should not affect the compiled code).
850    
851    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
852        compile-time error is now given if \c is not followed by an ASCII
853        character, that is, a byte less than 128. (In EBCDIC mode, the code is
854        different, and any byte value is allowed.)
855    
856    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
857        START_OPTIMIZE option, which is now allowed at compile time - but just
858        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
859        to pcregrep and other applications that have no direct access to PCRE
860        options. The new /Y option in pcretest sets this option when calling
861        pcre_compile().
862    
863    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
864        back references. Groups containing recursive back references were forced to
865        be atomic by that change, but in the case of named groups, the amount of
866        memory required was incorrectly computed, leading to "Failed: internal
867        error: code overflow". This has been fixed.
868    
869    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
870        pcretest.c, to avoid build problems in some Borland environments.
871    
872    
873    Version 8.10 25-Jun-2010
874    ------------------------
875    
876    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
877        THEN.
878    
879    2.  (*ACCEPT) was not working when inside an atomic group.
880    
881    3.  Inside a character class, \B is treated as a literal by default, but
882        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
883        causes the error). The code is unchanged, but I tidied the documentation.
884    
885    4.  Inside a character class, PCRE always treated \R and \X as literals,
886        whereas Perl faults them if its -w option is set. I have changed PCRE so
887        that it faults them when PCRE_EXTRA is set.
888    
889    5.  Added support for \N, which always matches any character other than
890        newline. (It is the same as "." when PCRE_DOTALL is not set.)
891    
892    6.  When compiling pcregrep with newer versions of gcc which may have
893        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
894        declared with attribute warn_unused_result" were given. Just casting the
895        result to (void) does not stop the warnings; a more elaborate fudge is
896        needed. I've used a macro to implement this.
897    
898    7.  Minor change to pcretest.c to avoid a compiler warning.
899    
900    8.  Added four artifical Unicode properties to help with an option to make
901        \s etc use properties (see next item). The new properties are: Xan
902        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
903    
904    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
905        use Unicode properties. (*UCP) at the start of a pattern can be used to set
906        this option. Modified pcretest to add /W to test this facility. Added
907        REG_UCP to make it available via the POSIX interface.
908    
909    10. Added --line-buffered to pcregrep.
910    
911    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
912        studied, and the match started with a letter with a code point greater than
913        127 whose first byte was different to the first byte of the other case of
914        the letter, the other case of this starting letter was not recognized
915        (#976).
916    
917    12. If a pattern that was studied started with a repeated Unicode property
918        test, for example, \p{Nd}+, there was the theoretical possibility of
919        setting up an incorrect bitmap of starting bytes, but fortunately it could
920        not have actually happened in practice until change 8 above was made (it
921        added property types that matched character-matching opcodes).
922    
923    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
924        possible starting bytes for non-anchored patterns.
925    
926    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
927        \R, and also a number of cases that involve Unicode properties, both
928        explicit and implicit when PCRE_UCP is set.
929    
930    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
931        input, it could crash or give wrong results if characters with values
932        greater than 0xc0 were present in the subject string. (Detail: it assumed
933        UTF-8 input when processing these items.)
934    
935    16. Added a lot of (int) casts to avoid compiler warnings in systems where
936        size_t is 64-bit (#991).
937    
938    17. Added a check for running out of memory when PCRE is compiled with
939        --disable-stack-for-recursion (#990).
940    
941    18. If the last data line in a file for pcretest does not have a newline on
942        the end, a newline was missing in the output.
943    
944    19. The default pcre_chartables.c file recognizes only ASCII characters (values
945        less than 128) in its various bitmaps. However, there is a facility for
946        generating tables according to the current locale when PCRE is compiled. It
947        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
948        characters, are recognized by isspace() and therefore were getting set in
949        these tables, and indeed these tables seem to approximate to ISO 8859. This
950        caused a problem in UTF-8 mode when pcre_study() was used to create a list
951        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
952        which of course cannot start UTF-8 characters. I have changed the code so
953        that only real ASCII characters (less than 128) and the correct starting
954        bytes for UTF-8 encodings are set for characters greater than 127 when in
955        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
956        altogether.)
957    
958    20. Added the /T option to pcretest so as to be able to run tests with non-
959        standard character tables, thus making it possible to include the tests
960        used for 19 above in the standard set of tests.
961    
962    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
963        reference to a subpattern the other side of a comment that contains an
964        opening parenthesis caused either an internal compiling error, or a
965        reference to the wrong subpattern.
966    
967    
968    Version 8.02 19-Mar-2010
969    ------------------------
970    
971    1.  The Unicode data tables have been updated to Unicode 5.2.0.
972    
973    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
974        configured.
975    
976    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
977        original author of that file, following a query about its status.
978    
979    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
980        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
981    
982    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
983        quantifier applied to a forward-referencing subroutine call, could compile
984        incorrect code or give the error "internal error: previously-checked
985        referenced subpattern not found".
986    
987    6.  Both MS Visual Studio and Symbian OS have problems with initializing
988        variables to point to external functions. For these systems, therefore,
989        pcre_malloc etc. are now initialized to local functions that call the
990        relevant global functions.
991    
992    7.  There were two entries missing in the vectors called coptable and poptable
993        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
994        I've fixed the data, and added a kludgy way of testing at compile time that
995        the lengths are correct (equal to the number of opcodes).
996    
997    8.  Following on from 7, I added a similar kludge to check the length of the
998        eint vector in pcreposix.c.
999    
1000    9.  Error texts for pcre_compile() are held as one long string to avoid too
1001        much relocation at load time. To find a text, the string is searched,
1002        counting zeros. There was no check for running off the end of the string,
1003        which could happen if a new error number was added without updating the
1004        string.
1005    
1006    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1007    
1008    11. \K was not working if it appeared in an atomic group or in a group that
1009        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1010        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1011        the assertion is positive, but not if it is negative.
1012    
1013    12. Change 11 fortuitously reduced the size of the stack frame used in the
1014        "match()" function of pcre_exec.c by one pointer. Forthcoming
1015        implementation of support for (*MARK) will need an extra pointer on the
1016        stack; I have reserved it now, so that the stack frame size does not
1017        decrease.
1018    
1019    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1020        item in branch that calls a recursion is a subroutine call - as in the
1021        second branch in the above example - was incorrectly given the compile-
1022        time error "recursive call could loop indefinitely" because pcre_compile()
1023        was not correctly checking the subroutine for matching a non-empty string.
1024    
1025    14. The checks for overrunning compiling workspace could trigger after an
1026        overrun had occurred. This is a "should never occur" error, but it can be
1027        triggered by pathological patterns such as hundreds of nested parentheses.
1028        The checks now trigger 100 bytes before the end of the workspace.
1029    
1030    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1031    
1032    
1033    Version 8.01 19-Jan-2010
1034    ------------------------
1035    
1036  1.  If a pattern contained a conditional subpattern with only one branch (in  1.  If a pattern contained a conditional subpattern with only one branch (in
1037      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1038      computed the wrong minimum data length (which is of course zero for such      computed the wrong minimum data length (which is of course zero for such
1039      subpatterns).      subpatterns). This could cause incorrect "no match" results.
1040    
1041  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1042      the pattern is reset in the first branch, pcre_compile() failed with      the pattern is reset in the first branch, pcre_compile() failed with
# Line 61  Version 8.01 11-Dec-09 Line 1090  Version 8.01 11-Dec-09
1090      custom one, because of the following reported problem in Windows:      custom one, because of the following reported problem in Windows:
1091    
1092        - libbz2 uses the Pascal calling convention (WINAPI) for the functions        - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1093          under Win32.            under Win32.
1094        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1095          therefore missing the function definition.            therefore missing the function definition.
1096        - The compiler thus generates a "C" signature for the test function.        - The compiler thus generates a "C" signature for the test function.
1097        - The linker fails to find the "C" function.        - The linker fails to find the "C" function.
1098        - PCRE fails to configure if asked to do so against libbz2.        - PCRE fails to configure if asked to do so against libbz2.
1099    
1100    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1101        messages were output:
1102    
1103          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1104          rerunning libtoolize, to keep the correct libtool macros in-tree.
1105          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1106    
1107        I have done both of these things.
1108    
1109    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1110        most of the time, it *can* run out if it is given a pattern that contains a
1111        runaway infinite recursion. I updated the discussion in the pcrestack man
1112        page.
1113    
1114    13. Now that we have gone to the x.xx style of version numbers, the minor
1115        version may start with zero. Using 08 or 09 is a bad idea because users
1116        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1117        interpreted as invalid octal numbers. I've updated the previous comment in
1118        configure.ac, and also added a check that gives an error if 08 or 09 are
1119        used.
1120    
1121    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1122        causing partial matching to fail when the end of the subject matched \W
1123        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1124    
1125    15. There were some discrepancies between the declarations in pcre_internal.h
1126        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1127        their definitions. The declarations used "const uschar *" and the
1128        definitions used USPTR. Even though USPTR is normally defined as "const
1129        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1130        reported that: "This difference in casting confuses some C++ compilers, for
1131        example, SunCC recognizes above declarations as different functions and
1132        generates broken code for hbpcre." I have changed the declarations to use
1133        USPTR.
1134    
1135    16. GNU libtool is named differently on some systems. The autogen.sh script now
1136        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1137        (FreeBSD).
1138    
1139    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1140        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1141        comment: "Figure out how to create a longlong from a string: strtoll and
1142        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1143        instance, but it only takes 2 args instead of 3!"
1144    
1145    18. A subtle bug concerned with back references has been fixed by a change of
1146        specification, with a corresponding code fix. A pattern such as
1147        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1148        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1149        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1150        same bug. Such groups have to be quantified to be useful, or contained
1151        inside another quantified group. (If there's no repetition, the reference
1152        can never match.) The problem arises because, having left the group and
1153        moved on to the rest of the pattern, a later failure that backtracks into
1154        the group uses the captured value from the final iteration of the group
1155        rather than the correct earlier one. I have fixed this in PCRE by forcing
1156        any group that contains a reference to itself to be an atomic group; that
1157        is, there cannot be any backtracking into it once it has completed. This is
1158        similar to recursive and subroutine calls.
1159    
1160    
1161  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09
1162  ----------------------  ----------------------

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