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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.7 05-Mar-08  Version 8.31
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    
73    Version 8.30 04-February-2012
74    -----------------------------
75    
76    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
77        name is defined in ctype.h.
78    
79    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
80        only in quite long subpatterns.
81    
82    3.  Removed the function pcre_info(), which has been obsolete and deprecated
83        since it was replaced by pcre_fullinfo() in February 2000.
84    
85    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
86        match a (*MARK), and the match failed at the start of the subject, a
87        reference to memory before the start of the subject could occur. This bug
88        was introduced by fix 17 of release 8.21.
89    
90    5.  A reference to an unset group with zero minimum repetition was giving
91        totally wrong answers (in non-JavaScript-compatibility mode). For example,
92        /(another)?(\1?)test/ matched against "hello world test". This bug was
93        introduced in release 8.13.
94    
95    6.  Add support for 16-bit character strings (a large amount of work involving
96        many changes and refactorings).
97    
98    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
99        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
100        from a file.
101    
102    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
103        rounding is not applied in this particular case).
104    
105    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
106        if they appear, or are escaped, in patterns.
107    
108    10. Get rid of a number of -Wunused-but-set-variable warnings.
109    
110    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
111        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
112        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
113        also returns the mark "x". This bug applied to capturing parentheses,
114        non-capturing parentheses, and atomic parentheses. It also applied to some
115        assertions.
116    
117    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
118        information out of configure.ac instead of relying on pcre.h.generic, which
119        is not stored in the repository.
120    
121    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
122        -lreadline.
123    
124    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
125    
126    15. Applied Graycode's patch to put the top-level frame on the stack rather
127        than the heap when not using the stack for recursion. This gives a
128        performance improvement in many cases when recursion is not deep.
129    
130    16. Experimental code added to "pcretest -C" to output the stack frame size.
131    
132    
133    Version 8.21 12-Dec-2011
134    ------------------------
135    
136    1.  Updating the JIT compiler.
137    
138    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
139        are added as well.
140    
141    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
142        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
143        calling _pcre_jit_exec. Some extra comments are added.
144    
145    4.  (*MARK) settings inside atomic groups that do not contain any capturing
146        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
147        was introduced by change 18 for 8.20.
148    
149    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
150        ECMA-262 standard.
151    
152    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
153        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
154        This bug was probably introduced by change 9 of 8.13.
155    
156    7.  While fixing 6 above, I noticed that a number of other items were being
157        incorrectly rejected as "not fixed length". This arose partly because newer
158        opcodes had not been added to the fixed-length checking code. I have (a)
159        corrected the bug and added tests for these items, and (b) arranged for an
160        error to occur if an unknown opcode is encountered while checking for fixed
161        length instead of just assuming "not fixed length". The items that were
162        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
163        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
164        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
165    
166    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
167        being incorrectly compiled and would have given unpredicatble results.
168    
169    9.  A possessively repeated subpattern with minimum repeat count greater than
170        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
171        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
172        the first (A) could occur when it should not.
173    
174    10. Add a cast and remove a redundant test from the code.
175    
176    11. JIT should use pcre_malloc/pcre_free for allocation.
177    
178    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
179        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
180        is anything other than /usr, -L is still shown).
181    
182    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
183    
184    14. Perl does not support \N without a following name in a [] class; PCRE now
185        also gives an error.
186    
187    15. If a forward reference was repeated with an upper limit of around 2000,
188        it caused the error "internal error: overran compiling workspace". The
189        maximum number of forward references (including repeats) was limited by the
190        internal workspace, and dependent on the LINK_SIZE. The code has been
191        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
192        the default depends on LINK_SIZE. There is a new upper limit (for safety)
193        of around 200,000 forward references. While doing this, I also speeded up
194        the filling in of repeated forward references.
195    
196    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
197        incorrectly expecting the subject to contain another "a" after the start.
198    
199    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
200        in the match, the SKIP should be ignored. This was not happening; instead
201        the SKIP was being treated as NOMATCH. For patterns such as
202        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
203        tested.
204    
205    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
206        now much more compatible with Perl, in particular in cases where the result
207        is a non-match for a non-anchored pattern. For example, if
208        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
209        "m", where previously it did not return a name. A side effect of this
210        change is that for partial matches, the last encountered mark name is
211        returned, as for non matches. A number of tests that were previously not
212        Perl-compatible have been moved into the Perl-compatible test files. The
213        refactoring has had the pleasing side effect of removing one argument from
214        the match() function, thus reducing its stack requirements.
215    
216    19. If the /S+ option was used in pcretest to study a pattern using JIT,
217        subsequent uses of /S (without +) incorrectly behaved like /S+.
218    
219    21. Retrieve executable code size support for the JIT compiler and fixing
220        some warnings.
221    
222    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
223        not work when the shorter character appeared right at the end of the
224        subject string.
225    
226    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
227        systems.
228    
229    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
230        output it when the /M option is used in pcretest.
231    
232    25. The CheckMan script was not being included in the distribution. Also, added
233        an explicit "perl" to run Perl scripts from the PrepareRelease script
234        because this is reportedly needed in Windows.
235    
236    26. If study data was being save in a file and studying had not found a set of
237        "starts with" bytes for the pattern, the data written to the file (though
238        never used) was taken from uninitialized memory and so caused valgrind to
239        complain.
240    
241    27. Updated RunTest.bat as provided by Sheri Pierce.
242    
243    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
244    
245    29. Computation of memory usage for the table of capturing group names was
246        giving an unnecessarily large value.
247    
248    
249    Version 8.20 21-Oct-2011
250    ------------------------
251    
252    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
253        a POSIX class. After further experiments with Perl, which convinced me that
254        Perl has bugs and confusions, a closing square bracket is no longer allowed
255        in a POSIX name. This bug also affected patterns with classes that started
256        with full stops.
257    
258    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
259        captured substring, but while checking the failing first alternative,
260        substring 1 is temporarily captured. If the output vector supplied to
261        pcre_exec() was not big enough for this capture, the yield of the function
262        was still zero ("insufficient space for captured substrings"). This cannot
263        be totally fixed without adding another stack variable, which seems a lot
264        of expense for a edge case. However, I have improved the situation in cases
265        such as /(a)(b)x|abc/ matched against "abc", where the return code
266        indicates that fewer than the maximum number of slots in the ovector have
267        been set.
268    
269    3.  Related to (2) above: when there are more back references in a pattern than
270        slots in the output vector, pcre_exec() uses temporary memory during
271        matching, and copies in the captures as far as possible afterwards. It was
272        using the entire output vector, but this conflicts with the specification
273        that only 2/3 is used for passing back captured substrings. Now it uses
274        only the first 2/3, for compatibility. This is, of course, another edge
275        case.
276    
277    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
278        main code base, and can be used by building with --enable-jit. When this is
279        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
280        runtime --no-jit option is given.
281    
282    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
283        ovector, the return from the function was zero, implying that there were
284        other matches that did not fit. The correct "exactly full" value is now
285        returned.
286    
287    6.  If a subpattern that was called recursively or as a subroutine contained
288        (*PRUNE) or any other control that caused it to give a non-standard return,
289        invalid errors such as "Error -26 (nested recursion at the same subject
290        position)" or even infinite loops could occur.
291    
292    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
293        computing the minimum length on reaching *ACCEPT, and so ended up with the
294        wrong value of 1 rather than 0. Further investigation indicates that
295        computing a minimum subject length in the presence of *ACCEPT is difficult
296        (think back references, subroutine calls), and so I have changed the code
297        so that no minimum is registered for a pattern that contains *ACCEPT.
298    
299    8.  If (*THEN) was present in the first (true) branch of a conditional group,
300        it was not handled as intended. [But see 16 below.]
301    
302    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
303        Sheri Pierce.
304    
305    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
306        the first byte in a match must be "a".
307    
308    11. Change 17 for 8.13 increased the recursion depth for patterns like
309        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
310        pattern contains any instances of (*THEN). If it does not, the old
311        optimizations are restored. It would be nice to do this on a per-group
312        basis, but at the moment that is not feasible.
313    
314    12. In some environments, the output of pcretest -C is CRLF terminated. This
315        broke RunTest's code that checks for the link size. A single white space
316        character after the value is now allowed for.
317    
318    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
319        For "fr", it uses the Windows-specific input and output files.
320    
321    14. If (*THEN) appeared in a group that was called recursively or as a
322        subroutine, it did not work as intended. [But see next item.]
323    
324    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
325        pattern fragments (but not containing any | characters). If A and B are
326        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
327        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
328        D. In other words, Perl considers parentheses that do not contain any |
329        characters to be part of a surrounding alternative, whereas PCRE was
330        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
331        differently. PCRE now behaves in the same way as Perl, except in the case
332        of subroutine/recursion calls such as (?1) which have in any case always
333        been different (but PCRE had them first :-).
334    
335    16. Related to 15 above: Perl does not treat the | in a conditional group as
336        creating alternatives. Such a group is treated in the same way as an
337        ordinary group without any | characters when processing (*THEN). PCRE has
338        been changed to match Perl's behaviour.
339    
340    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
341        RunGrepTest script failed.
342    
343    18. Change 22 for version 13 caused atomic groups to use more stack. This is
344        inevitable for groups that contain captures, but it can lead to a lot of
345        stack use in large patterns. The old behaviour has been restored for atomic
346        groups that do not contain any capturing parentheses.
347    
348    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
349        suppress the check for a minimum subject length at run time. (If it was
350        given to pcre_exec() or pcre_dfa_exec() it did work.)
351    
352    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
353        fail to work when decoding hex characters in data strings in EBCDIC
354        environments.
355    
356    21. It appears that in at least one Mac OS environment, the isxdigit() function
357        is implemented as a macro that evaluates to its argument more than once,
358        contravening the C 90 Standard (I haven't checked a later standard). There
359        was an instance in pcretest which caused it to go wrong when processing
360        \x{...} escapes in subject strings. The has been rewritten to avoid using
361        things like p++ in the argument of isxdigit().
362    
363    
364    Version 8.13 16-Aug-2011
365    ------------------------
366    
367    1.  The Unicode data tables have been updated to Unicode 6.0.0.
368    
369    2.  Two minor typos in pcre_internal.h have been fixed.
370    
371    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
372        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
373        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
374    
375    4.  There were a number of related bugs in the code for matching backrefences
376        caselessly in UTF-8 mode when codes for the characters concerned were
377        different numbers of bytes. For example, U+023A and U+2C65 are an upper
378        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
379        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
380        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
381        2-byte code at the end of the subject (it thought there wasn't enough data
382        left).
383    
384    5.  Comprehensive information about what went wrong is now returned by
385        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
386        as the output vector has at least 2 elements. The offset of the start of
387        the failing character and a reason code are placed in the vector.
388    
389    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
390        now returned is for the first byte of the failing character, instead of the
391        last byte inspected. This is an incompatible change, but I hope it is small
392        enough not to be a problem. It makes the returned offset consistent with
393        pcre_exec() and pcre_dfa_exec().
394    
395    7.  pcretest now gives a text phrase as well as the error number when
396        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
397        failure, the offset and reason code are output.
398    
399    8.  When \R was used with a maximizing quantifier it failed to skip backwards
400        over a \r\n pair if the subsequent match failed. Instead, it just skipped
401        back over a single character (\n). This seems wrong (because it treated the
402        two characters as a single entity when going forwards), conflicts with the
403        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
404        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
405        has been changed.
406    
407    9.  Some internal refactoring has changed the processing so that the handling
408        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
409        time (the PCRE_DOTALL option was changed this way some time ago: version
410        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
411        which was always a bit of a fudge. It also means that there is one less
412        argument for the match() function, which reduces its stack requirements
413        slightly. This change also fixes an incompatibility with Perl: the pattern
414        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
415    
416    10. More internal refactoring has drastically reduced the number of recursive
417        calls to match() for possessively repeated groups such as (abc)++ when
418        using pcre_exec().
419    
420    11. While implementing 10, a number of bugs in the handling of groups were
421        discovered and fixed:
422    
423        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
424        (a|)*(?1) gave a compile-time internal error.
425        ((a|)+)+  did not notice that the outer group could match an empty string.
426        (^a|^)+   was not marked as anchored.
427        (.*a|.*)+ was not marked as matching at start or after a newline.
428    
429    12. Yet more internal refactoring has removed another argument from the match()
430        function. Special calls to this function are now indicated by setting a
431        value in a variable in the "match data" data block.
432    
433    13. Be more explicit in pcre_study() instead of relying on "default" for
434        opcodes that mean there is no starting character; this means that when new
435        ones are added and accidentally left out of pcre_study(), testing should
436        pick them up.
437    
438    14. The -s option of pcretest has been documented for ages as being an old
439        synonym of -m (show memory usage). I have changed it to mean "force study
440        for every regex", that is, assume /S for every regex. This is similar to -i
441        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
442        using it. It makes it easier to run collections of tests with and without
443        study enabled, and thereby test pcre_study() more easily. All the standard
444        tests are now run with and without -s (but some patterns can be marked as
445        "never study" - see 20 below).
446    
447    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
448        restoration of the capturing data to the outer values was not happening
449        correctly.
450    
451    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
452        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
453        pattern had matched an empty string, and so incorrectly returned a no
454        match.
455    
456    17. There was optimizing code for the last branch of non-capturing parentheses,
457        and also for the obeyed branch of a conditional subexpression, which used
458        tail recursion to cut down on stack usage. Unfortunately, now that there is
459        the possibility of (*THEN) occurring in these branches, tail recursion is
460        no longer possible because the return has to be checked for (*THEN). These
461        two optimizations have therefore been removed. [But see 8.20/11 above.]
462    
463    18. If a pattern containing \R was studied, it was assumed that \R always
464        matched two bytes, thus causing the minimum subject length to be
465        incorrectly computed because \R can also match just one byte.
466    
467    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
468        was incorrectly computed.
469    
470    20. If /S is present twice on a test pattern in pcretest input, it now
471        *disables* studying, thereby overriding the use of -s on the command line
472        (see 14 above). This is necessary for one or two tests to keep the output
473        identical in both cases.
474    
475    21. When (*ACCEPT) was used in an assertion that matched an empty string and
476        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
477    
478    22. When an atomic group that contained a capturing parenthesis was
479        successfully matched, but the branch in which it appeared failed, the
480        capturing was not being forgotten if a higher numbered group was later
481        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
482        group 1 to "a", when in fact it should be unset. This applied to multi-
483        branched capturing and non-capturing groups, repeated or not, and also to
484        positive assertions (capturing in negative assertions does not happen
485        in PCRE) and also to nested atomic groups.
486    
487    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
488        subject after a captured substring, to make it easier to tell which of a
489        number of identical substrings has been captured.
490    
491    24. The way atomic groups are processed by pcre_exec() has been changed so that
492        if they are repeated, backtracking one repetition now resets captured
493        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
494        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
495        "aaa". Previously, it would have been "a". As part of this code
496        refactoring, the way recursive calls are handled has also been changed.
497    
498    25. If an assertion condition captured any substrings, they were not passed
499        back unless some other capturing happened later. For example, if
500        (?(?=(a))a) was matched against "a", no capturing was returned.
501    
502    26. When studying a pattern that contained subroutine calls or assertions,
503        the code for finding the minimum length of a possible match was handling
504        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
505        group 1 called group 2 while simultaneously a separate group 2 called group
506        1). A stack overflow occurred in this case. I have fixed this by limiting
507        the recursion depth to 10.
508    
509    27. Updated RunTest.bat in the distribution to the version supplied by Tom
510        Fortmann. This supports explicit test numbers on the command line, and has
511        argument validation and error reporting.
512    
513    28. An instance of \X with an unlimited repeat could fail if at any point the
514        first character it looked at was a mark character.
515    
516    29. Some minor code refactoring concerning Unicode properties and scripts
517        should reduce the stack requirement of match() slightly.
518    
519    30. Added the '=' option to pcretest to check the setting of unused capturing
520        slots at the end of the pattern, which are documented as being -1, but are
521        not included in the return count.
522    
523    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
524        compiled something random. Now it gives a compile-time error (as does
525        Perl).
526    
527    32. A *MARK encountered during the processing of a positive assertion is now
528        recorded and passed back (compatible with Perl).
529    
530    33. If --only-matching or --colour was set on a pcregrep call whose pattern
531        had alternative anchored branches, the search for a second match in a line
532        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
533        matched the line "0102" twice. The same bug affected patterns that started
534        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
535        twice.
536    
537    34. Previously, PCRE did not allow quantification of assertions. However, Perl
538        does, and because of capturing effects, quantifying parenthesized
539        assertions may at times be useful. Quantifiers are now allowed for
540        parenthesized assertions.
541    
542    35. A minor code tidy in pcre_compile() when checking options for \R usage.
543    
544    36. \g was being checked for fancy things in a character class, when it should
545        just be a literal "g".
546    
547    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
548        appearance of a nested POSIX class supersedes an apparent external class.
549        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
550        unescaped square brackets may also appear as part of class names. For
551        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
552        more like Perl. (But see 8.20/1 above.)
553    
554    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
555        was because it thought it was \N{name}, which is not supported).
556    
557    39. Add minix to OS list not supporting the -S option in pcretest.
558    
559    40. PCRE tries to detect cases of infinite recursion at compile time, but it
560        cannot analyze patterns in sufficient detail to catch mutual recursions
561        such as ((?1))((?2)). There is now a runtime test that gives an error if a
562        subgroup is called recursively as a subpattern for a second time at the
563        same position in the subject string. In previous releases this might have
564        been caught by the recursion limit, or it might have run out of stack.
565    
566    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
567        happen only once. PCRE was, however incorrectly giving a compile time error
568        "recursive call could loop indefinitely" because it cannot analyze the
569        pattern in sufficient detail. The compile time test no longer happens when
570        PCRE is compiling a conditional subpattern, but actual runaway loops are
571        now caught at runtime (see 40 above).
572    
573    42. It seems that Perl allows any characters other than a closing parenthesis
574        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
575        has been changed to be the same.
576    
577    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
578        as not to get warnings when autogen.sh is called. Also changed
579        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
580    
581    44. To help people who use pcregrep to scan files containing exceedingly long
582        lines, the following changes have been made:
583    
584        (a) The default value of the buffer size parameter has been increased from
585            8K to 20K. (The actual buffer used is three times this size.)
586    
587        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
588            PCRE is built.
589    
590        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
591            to be set at run time.
592    
593        (d) Numerical values in pcregrep options can be followed by K or M, for
594            example --buffer-size=50K.
595    
596        (e) If a line being scanned overflows pcregrep's buffer, an error is now
597            given and the return code is set to 2.
598    
599    45. Add a pointer to the latest mark to the callout data block.
600    
601    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
602        partial match of an empty string instead of no match. This was specific to
603        the use of ".".
604    
605    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
606        complete match instead of a partial match. This bug was dependent on both
607        the PCRE_UTF8 and PCRE_DOTALL options being set.
608    
609    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
610        starting byte set, because \b was not being ignored.
611    
612    
613    Version 8.12 15-Jan-2011
614    ------------------------
615    
616    1.  Fixed some typos in the markup of the man pages, and wrote a script that
617        checks for such things as part of the documentation building process.
618    
619    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
620        --match-limit and --recursion-limit options (added for 8.11). In
621        particular, this made one of the standard tests fail. (The integer value
622        went into the wrong half of a long int.)
623    
624    3.  If the --colour option was given to pcregrep with -v (invert match), it
625        did strange things, either producing crazy output, or crashing. It should,
626        of course, ignore a request for colour when reporting lines that do not
627        match.
628    
629    4.  Another pcregrep bug caused similar problems if --colour was specified with
630        -M (multiline) and the pattern match finished with a line ending.
631    
632    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
633        matched in multiline mode, the following line was shown as part of the
634        match. This seems wrong, so I have changed it.
635    
636    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
637        the check for further matches in the same line (so they could be coloured)
638        to overrun the end of the current line. If another match was found, it was
639        incorrectly shown (and then shown again when found in the next line).
640    
641    7.  If pcregrep was compiled under Windows, there was a reference to the
642        function pcregrep_exit() before it was defined. I am assuming this was
643        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
644        reported by a user. I've moved the definition above the reference.
645    
646    
647    Version 8.11 10-Dec-2010
648    ------------------------
649    
650    1.  (*THEN) was not working properly if there were untried alternatives prior
651        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
652        backtracked to try for "b" instead of moving to the next alternative branch
653        at the same level (in this case, to look for "c"). The Perl documentation
654        is clear that when (*THEN) is backtracked onto, it goes to the "next
655        alternative in the innermost enclosing group".
656    
657    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
658        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
659        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
660        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
661        (*THEN).
662    
663    3.  If \s appeared in a character class, it removed the VT character from
664        the class, even if it had been included by some previous item, for example
665        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
666        of \s, but is part of the POSIX "space" class.)
667    
668    4.  A partial match never returns an empty string (because you can always
669        match an empty string at the end of the subject); however the checking for
670        an empty string was starting at the "start of match" point. This has been
671        changed to the "earliest inspected character" point, because the returned
672        data for a partial match starts at this character. This means that, for
673        example, /(?<=abc)def/ gives a partial match for the subject "abc"
674        (previously it gave "no match").
675    
676    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
677        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
678        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
679        has an implication that the given string is incomplete (because a partial
680        match is preferred over a full match). For this reason, these items now
681        give a partial match in this situation. [Aside: previously, the one case
682        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
683        match rather than a full match, which was wrong by the old rules, but is
684        now correct.]
685    
686    6.  There was a bug in the handling of #-introduced comments, recognized when
687        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
688        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
689        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
690        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
691        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
692        places in pcre_compile().
693    
694    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
695        comments when looking ahead for named forward references to subpatterns,
696        the only newline sequence it recognized was NL. It now handles newlines
697        according to the set newline convention.
698    
699    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
700        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
701        cater for a lack of strerror(). These oversights have been fixed.
702    
703    9.  Added --match-limit and --recursion-limit to pcregrep.
704    
705    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
706    
707    11. When the -o option was used, pcregrep was setting a return code of 1, even
708        when matches were found, and --line-buffered was not being honoured.
709    
710    12. Added an optional parentheses number to the -o and --only-matching options
711        of pcregrep.
712    
713    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
714        can match an empty string. The code to do it in pcretest and pcredemo
715        needed fixing:
716    
717        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
718            only one byte after an empty string match just before CRLF (this case
719            just got forgotten; "any" and "anycrlf" were OK).
720    
721        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
722            mode when an empty string match preceded an ASCII character followed by
723            a non-ASCII character. (The code for advancing by one character rather
724            than one byte was nonsense.)
725    
726        (c) The pcredemo.c sample program did not have any code at all to handle
727            the cases when CRLF is a valid newline sequence.
728    
729    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
730        as a starting offset was within the subject string. There is now a new
731        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
732        negative or greater than the length of the string. In order to test this,
733        pcretest is extended to allow the setting of negative starting offsets.
734    
735    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
736        starting offset points to the beginning of a UTF-8 character was
737        unnecessarily clumsy. I tidied it up.
738    
739    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
740        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
741    
742    17. Nobody had reported that the --include_dir option, which was added in
743        release 7.7 should have been called --include-dir (hyphen, not underscore)
744        for compatibility with GNU grep. I have changed it to --include-dir, but
745        left --include_dir as an undocumented synonym, and the same for
746        --exclude-dir, though that is not available in GNU grep, at least as of
747        release 2.5.4.
748    
749    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
750        characters from a string of bytes) have been redefined so as not to use
751        loops, in order to improve performance in some environments. At the same
752        time, I abstracted some of the common code into auxiliary macros to save
753        repetition (this should not affect the compiled code).
754    
755    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
756        compile-time error is now given if \c is not followed by an ASCII
757        character, that is, a byte less than 128. (In EBCDIC mode, the code is
758        different, and any byte value is allowed.)
759    
760    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
761        START_OPTIMIZE option, which is now allowed at compile time - but just
762        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
763        to pcregrep and other applications that have no direct access to PCRE
764        options. The new /Y option in pcretest sets this option when calling
765        pcre_compile().
766    
767    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
768        back references. Groups containing recursive back references were forced to
769        be atomic by that change, but in the case of named groups, the amount of
770        memory required was incorrectly computed, leading to "Failed: internal
771        error: code overflow". This has been fixed.
772    
773    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
774        pcretest.c, to avoid build problems in some Borland environments.
775    
776    
777    Version 8.10 25-Jun-2010
778    ------------------------
779    
780    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
781        THEN.
782    
783    2.  (*ACCEPT) was not working when inside an atomic group.
784    
785    3.  Inside a character class, \B is treated as a literal by default, but
786        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
787        causes the error). The code is unchanged, but I tidied the documentation.
788    
789    4.  Inside a character class, PCRE always treated \R and \X as literals,
790        whereas Perl faults them if its -w option is set. I have changed PCRE so
791        that it faults them when PCRE_EXTRA is set.
792    
793    5.  Added support for \N, which always matches any character other than
794        newline. (It is the same as "." when PCRE_DOTALL is not set.)
795    
796    6.  When compiling pcregrep with newer versions of gcc which may have
797        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
798        declared with attribute warn_unused_result" were given. Just casting the
799        result to (void) does not stop the warnings; a more elaborate fudge is
800        needed. I've used a macro to implement this.
801    
802    7.  Minor change to pcretest.c to avoid a compiler warning.
803    
804    8.  Added four artifical Unicode properties to help with an option to make
805        \s etc use properties (see next item). The new properties are: Xan
806        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
807    
808    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
809        use Unicode properties. (*UCP) at the start of a pattern can be used to set
810        this option. Modified pcretest to add /W to test this facility. Added
811        REG_UCP to make it available via the POSIX interface.
812    
813    10. Added --line-buffered to pcregrep.
814    
815    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
816        studied, and the match started with a letter with a code point greater than
817        127 whose first byte was different to the first byte of the other case of
818        the letter, the other case of this starting letter was not recognized
819        (#976).
820    
821    12. If a pattern that was studied started with a repeated Unicode property
822        test, for example, \p{Nd}+, there was the theoretical possibility of
823        setting up an incorrect bitmap of starting bytes, but fortunately it could
824        not have actually happened in practice until change 8 above was made (it
825        added property types that matched character-matching opcodes).
826    
827    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
828        possible starting bytes for non-anchored patterns.
829    
830    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
831        \R, and also a number of cases that involve Unicode properties, both
832        explicit and implicit when PCRE_UCP is set.
833    
834    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
835        input, it could crash or give wrong results if characters with values
836        greater than 0xc0 were present in the subject string. (Detail: it assumed
837        UTF-8 input when processing these items.)
838    
839    16. Added a lot of (int) casts to avoid compiler warnings in systems where
840        size_t is 64-bit (#991).
841    
842    17. Added a check for running out of memory when PCRE is compiled with
843        --disable-stack-for-recursion (#990).
844    
845    18. If the last data line in a file for pcretest does not have a newline on
846        the end, a newline was missing in the output.
847    
848    19. The default pcre_chartables.c file recognizes only ASCII characters (values
849        less than 128) in its various bitmaps. However, there is a facility for
850        generating tables according to the current locale when PCRE is compiled. It
851        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
852        characters, are recognized by isspace() and therefore were getting set in
853        these tables, and indeed these tables seem to approximate to ISO 8859. This
854        caused a problem in UTF-8 mode when pcre_study() was used to create a list
855        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
856        which of course cannot start UTF-8 characters. I have changed the code so
857        that only real ASCII characters (less than 128) and the correct starting
858        bytes for UTF-8 encodings are set for characters greater than 127 when in
859        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
860        altogether.)
861    
862    20. Added the /T option to pcretest so as to be able to run tests with non-
863        standard character tables, thus making it possible to include the tests
864        used for 19 above in the standard set of tests.
865    
866    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
867        reference to a subpattern the other side of a comment that contains an
868        opening parenthesis caused either an internal compiling error, or a
869        reference to the wrong subpattern.
870    
871    
872    Version 8.02 19-Mar-2010
873    ------------------------
874    
875    1.  The Unicode data tables have been updated to Unicode 5.2.0.
876    
877    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
878        configured.
879    
880    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
881        original author of that file, following a query about its status.
882    
883    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
884        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
885    
886    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
887        quantifier applied to a forward-referencing subroutine call, could compile
888        incorrect code or give the error "internal error: previously-checked
889        referenced subpattern not found".
890    
891    6.  Both MS Visual Studio and Symbian OS have problems with initializing
892        variables to point to external functions. For these systems, therefore,
893        pcre_malloc etc. are now initialized to local functions that call the
894        relevant global functions.
895    
896    7.  There were two entries missing in the vectors called coptable and poptable
897        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
898        I've fixed the data, and added a kludgy way of testing at compile time that
899        the lengths are correct (equal to the number of opcodes).
900    
901    8.  Following on from 7, I added a similar kludge to check the length of the
902        eint vector in pcreposix.c.
903    
904    9.  Error texts for pcre_compile() are held as one long string to avoid too
905        much relocation at load time. To find a text, the string is searched,
906        counting zeros. There was no check for running off the end of the string,
907        which could happen if a new error number was added without updating the
908        string.
909    
910    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
911    
912    11. \K was not working if it appeared in an atomic group or in a group that
913        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
914        \K is "not well defined" if used in an assertion. PCRE now accepts it if
915        the assertion is positive, but not if it is negative.
916    
917    12. Change 11 fortuitously reduced the size of the stack frame used in the
918        "match()" function of pcre_exec.c by one pointer. Forthcoming
919        implementation of support for (*MARK) will need an extra pointer on the
920        stack; I have reserved it now, so that the stack frame size does not
921        decrease.
922    
923    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
924        item in branch that calls a recursion is a subroutine call - as in the
925        second branch in the above example - was incorrectly given the compile-
926        time error "recursive call could loop indefinitely" because pcre_compile()
927        was not correctly checking the subroutine for matching a non-empty string.
928    
929    14. The checks for overrunning compiling workspace could trigger after an
930        overrun had occurred. This is a "should never occur" error, but it can be
931        triggered by pathological patterns such as hundreds of nested parentheses.
932        The checks now trigger 100 bytes before the end of the workspace.
933    
934    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
935    
936    
937    Version 8.01 19-Jan-2010
938    ------------------------
939    
940    1.  If a pattern contained a conditional subpattern with only one branch (in
941        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
942        computed the wrong minimum data length (which is of course zero for such
943        subpatterns). This could cause incorrect "no match" results.
944    
945    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
946        the pattern is reset in the first branch, pcre_compile() failed with
947        "internal error: code overflow at offset...". This happened only when
948        the reset was to the original external option setting. (An optimization
949        abstracts leading options settings into an external setting, which was the
950        cause of this.)
951    
952    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
953        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
954        assertion pattern did not match (meaning that the assertion was true), it
955        was incorrectly treated as false if the SKIP had been reached during the
956        matching. This also applied to assertions used as conditions.
957    
958    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
959        assertion subpattern, including such a pattern used as a condition,
960        unpredictable results occurred, instead of the error return
961        PCRE_ERROR_DFA_UITEM.
962    
963    5.  The C++ GlobalReplace function was not working like Perl for the special
964        situation when an empty string is matched. It now does the fancy magic
965        stuff that is necessary.
966    
967    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
968        removed. (These were left over from very, very early versions of PCRE.)
969    
970    7.  Some cosmetic changes to the code to make life easier when compiling it
971        as part of something else:
972    
973        (a) Change DEBUG to PCRE_DEBUG.
974    
975        (b) In pcre_compile(), rename the member of the "branch_chain" structure
976            called "current" as "current_branch", to prevent a collision with the
977            Linux macro when compiled as a kernel module.
978    
979        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
980            prevent a collision with the Linux macro when compiled as a kernel
981            module.
982    
983    8.  In pcre_compile() there are some checks for integer overflows that used to
984        cast potentially large values to (double). This has been changed to that
985        when building, a check for int64_t is made, and if it is found, it is used
986        instead, thus avoiding the use of floating point arithmetic. (There is no
987        other use of FP in PCRE.) If int64_t is not found, the fallback is to
988        double.
989    
990    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
991        2005 (difference between two addresses compared to an unsigned value).
992    
993    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
994        custom one, because of the following reported problem in Windows:
995    
996          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
997              under Win32.
998          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
999              therefore missing the function definition.
1000          - The compiler thus generates a "C" signature for the test function.
1001          - The linker fails to find the "C" function.
1002          - PCRE fails to configure if asked to do so against libbz2.
1003    
1004    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1005        messages were output:
1006    
1007          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1008          rerunning libtoolize, to keep the correct libtool macros in-tree.
1009          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1010    
1011        I have done both of these things.
1012    
1013    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1014        most of the time, it *can* run out if it is given a pattern that contains a
1015        runaway infinite recursion. I updated the discussion in the pcrestack man
1016        page.
1017    
1018    13. Now that we have gone to the x.xx style of version numbers, the minor
1019        version may start with zero. Using 08 or 09 is a bad idea because users
1020        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1021        interpreted as invalid octal numbers. I've updated the previous comment in
1022        configure.ac, and also added a check that gives an error if 08 or 09 are
1023        used.
1024    
1025    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1026        causing partial matching to fail when the end of the subject matched \W
1027        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1028    
1029    15. There were some discrepancies between the declarations in pcre_internal.h
1030        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1031        their definitions. The declarations used "const uschar *" and the
1032        definitions used USPTR. Even though USPTR is normally defined as "const
1033        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1034        reported that: "This difference in casting confuses some C++ compilers, for
1035        example, SunCC recognizes above declarations as different functions and
1036        generates broken code for hbpcre." I have changed the declarations to use
1037        USPTR.
1038    
1039    16. GNU libtool is named differently on some systems. The autogen.sh script now
1040        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1041        (FreeBSD).
1042    
1043    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1044        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1045        comment: "Figure out how to create a longlong from a string: strtoll and
1046        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1047        instance, but it only takes 2 args instead of 3!"
1048    
1049    18. A subtle bug concerned with back references has been fixed by a change of
1050        specification, with a corresponding code fix. A pattern such as
1051        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1052        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1053        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1054        same bug. Such groups have to be quantified to be useful, or contained
1055        inside another quantified group. (If there's no repetition, the reference
1056        can never match.) The problem arises because, having left the group and
1057        moved on to the rest of the pattern, a later failure that backtracks into
1058        the group uses the captured value from the final iteration of the group
1059        rather than the correct earlier one. I have fixed this in PCRE by forcing
1060        any group that contains a reference to itself to be an atomic group; that
1061        is, there cannot be any backtracking into it once it has completed. This is
1062        similar to recursive and subroutine calls.
1063    
1064    
1065    Version 8.00 19-Oct-09
1066    ----------------------
1067    
1068    1.  The table for translating pcre_compile() error codes into POSIX error codes
1069        was out-of-date, and there was no check on the pcre_compile() error code
1070        being within the table. This could lead to an OK return being given in
1071        error.
1072    
1073    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1074        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1075        in a Windows environment.
1076    
1077    3.  The pcregrep --count option prints the count for each file even when it is
1078        zero, as does GNU grep. However, pcregrep was also printing all files when
1079        --files-with-matches was added. Now, when both options are given, it prints
1080        counts only for those files that have at least one match. (GNU grep just
1081        prints the file name in this circumstance, but including the count seems
1082        more useful - otherwise, why use --count?) Also ensured that the
1083        combination -clh just lists non-zero counts, with no names.
1084    
1085    4.  The long form of the pcregrep -F option was incorrectly implemented as
1086        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1087        but it seems right to fix it, and I didn't think it was worth preserving
1088        the old behaviour.
1089    
1090    5.  The command line items --regex=pattern and --regexp=pattern were not
1091        recognized by pcregrep, which required --regex pattern or --regexp pattern
1092        (with a space rather than an '='). The man page documented the '=' forms,
1093        which are compatible with GNU grep; these now work.
1094    
1095    6.  No libpcreposix.pc file was created for pkg-config; there was just
1096        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1097    
1098    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1099        when UCP support is not needed, by modifying the Python script that
1100        generates it from Unicode data files. This should not matter if the module
1101        is correctly used as a library, but I received one complaint about 50K of
1102        unwanted data. My guess is that the person linked everything into his
1103        program rather than using a library. Anyway, it does no harm.
1104    
1105    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1106        was a minimum greater than 1 for a wide character in a possessive
1107        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1108        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1109        character. Chaos in the form of incorrect output or a compiling loop could
1110        result.
1111    
1112    9.  The restrictions on what a pattern can contain when partial matching is
1113        requested for pcre_exec() have been removed. All patterns can now be
1114        partially matched by this function. In addition, if there are at least two
1115        slots in the offset vector, the offset of the earliest inspected character
1116        for the match and the offset of the end of the subject are set in them when
1117        PCRE_ERROR_PARTIAL is returned.
1118    
1119    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1120        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1121        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1122        and may be more useful for multi-segment matching.
1123    
1124    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1125        used to be given if ever the end of the subject was reached; now it is
1126        given only if matching could not proceed because another character was
1127        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1128        string "Z", which now yields "no match" instead of "partial match". In the
1129        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1130        final character ended with (*FAIL).
1131    
1132    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1133        if the pattern had a "must contain" character that was already found in the
1134        earlier partial match, unless partial matching was again requested. For
1135        example, with the pattern /dog.(body)?/, the "must contain" character is
1136        "g". If the first part-match was for the string "dog", restarting with
1137        "sbody" failed. This bug has been fixed.
1138    
1139    13. The string returned by pcre_dfa_exec() after a partial match has been
1140        changed so that it starts at the first inspected character rather than the
1141        first character of the match. This makes a difference only if the pattern
1142        starts with a lookbehind assertion or \b or \B (\K is not supported by
1143        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1144        matching functions compatible, and I think it's the right thing to do.
1145    
1146    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1147        so that the demonstration program is easily available in environments where
1148        PCRE has not been installed from source.
1149    
1150    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1151        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1152        library.
1153    
1154    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1155        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1156        is not the first non-POSIX option to be added. Clearly some people find
1157        these options useful.
1158    
1159    17. If a caller to the POSIX matching function regexec() passes a non-zero
1160        value for nmatch with a NULL value for pmatch, the value of
1161        nmatch is forced to zero.
1162    
1163    18. RunGrepTest did not have a test for the availability of the -u option of
1164        the diff command, as RunTest does. It now checks in the same way as
1165        RunTest, and also checks for the -b option.
1166    
1167    19. If an odd number of negated classes containing just a single character
1168        interposed, within parentheses, between a forward reference to a named
1169        subpattern and the definition of the subpattern, compilation crashed with
1170        an internal error, complaining that it could not find the referenced
1171        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1172        [The bug was that it was starting one character too far in when skipping
1173        over the character class, thus treating the ] as data rather than
1174        terminating the class. This meant it could skip too much.]
1175    
1176    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1177        /g option in pcretest when the pattern contains \K, which makes it possible
1178        to have an empty string match not at the start, even when the pattern is
1179        anchored. Updated pcretest and pcredemo to use this option.
1180    
1181    21. If the maximum number of capturing subpatterns in a recursion was greater
1182        than the maximum at the outer level, the higher number was returned, but
1183        with unset values at the outer level. The correct (outer level) value is
1184        now given.
1185    
1186    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1187        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1188        make it do so. The string so far is captured, making this feature
1189        compatible with Perl.
1190    
1191    23. The tests have been re-organized, adding tests 11 and 12, to make it
1192        possible to check the Perl 5.10 features against Perl 5.10.
1193    
1194    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1195        pattern matches a fixed length string. PCRE did not allow this; now it
1196        does. Neither allows recursion.
1197    
1198    25. I finally figured out how to implement a request to provide the minimum
1199        length of subject string that was needed in order to match a given pattern.
1200        (It was back references and recursion that I had previously got hung up
1201        on.) This code has now been added to pcre_study(); it finds a lower bound
1202        to the length of subject needed. It is not necessarily the greatest lower
1203        bound, but using it to avoid searching strings that are too short does give
1204        some useful speed-ups. The value is available to calling programs via
1205        pcre_fullinfo().
1206    
1207    26. While implementing 25, I discovered to my embarrassment that pcretest had
1208        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1209        study optimizations had never been tested with that matching function.
1210        Oops. What is worse, even when it was passed study data, there was a bug in
1211        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1212        were also very few tests of studied patterns with pcre_dfa_exec().
1213    
1214    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1215        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1216        on the other side of the coin, they are no longer allowed to have different
1217        names, because these cannot be distinguished in PCRE, and this has caused
1218        confusion. (This is a difference from Perl.)
1219    
1220    28. When duplicate subpattern names are present (necessarily with different
1221        numbers, as required by 27 above), and a test is made by name in a
1222        conditional pattern, either for a subpattern having been matched, or for
1223        recursion in such a pattern, all the associated numbered subpatterns are
1224        tested, and the overall condition is true if the condition is true for any
1225        one of them. This is the way Perl works, and is also more like the way
1226        testing by number works.
1227    
1228    
1229    Version 7.9 11-Apr-09
1230    ---------------------
1231    
1232    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1233        (pcretest), all targets were linked against these libraries. This included
1234        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1235        libraries. This caused unwanted dependencies to be created. This problem
1236        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1237        pcretest is linked with readline.
1238    
1239    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1240        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1241        moved outside it again, because FALSE and TRUE are already defined in AIX,
1242        but BOOL is not.
1243    
1244    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1245        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1246    
1247    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1248        hyphens) following file names and line numbers when outputting matching
1249        lines. This is not true; no spaces are inserted. I have also clarified the
1250        wording for the --colour (or --color) option.
1251    
1252    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1253        was not coloured; this is different to GNU grep, so I have changed it to be
1254        the same.
1255    
1256    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1257        each matching line was coloured. Now it goes on to look for further matches
1258        of any of the test patterns, which is the same behaviour as GNU grep.
1259    
1260    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1261        doesn't make sense to accept an empty string match in pcregrep, so I have
1262        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1263        seems to be how GNU grep behaves.
1264    
1265    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1266        start or after a newline", because the conditional assertion was not being
1267        correctly handled. The rule now is that both the assertion and what follows
1268        in the first alternative must satisfy the test.
1269    
1270    9.  If auto-callout was enabled in a pattern with a conditional group whose
1271        condition was an assertion, PCRE could crash during matching, both with
1272        pcre_exec() and pcre_dfa_exec().
1273    
1274    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1275        used for matching.
1276    
1277    11. Unicode property support in character classes was not working for
1278        characters (bytes) greater than 127 when not in UTF-8 mode.
1279    
1280    12. Added the -M command line option to pcretest.
1281    
1282    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1283    
1284    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1285    
1286    16. Added comments and documentation about mis-use of no_arg in the C++
1287        wrapper.
1288    
1289    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1290        from Martin Jerabek that uses macro names for all relevant character and
1291        string constants.
1292    
1293    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1294        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1295        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1296        these, but not everybody uses configure.
1297    
1298    19. A conditional group that had only one branch was not being correctly
1299        recognized as an item that could match an empty string. This meant that an
1300        enclosing group might also not be so recognized, causing infinite looping
1301        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1302        with the subject "ab", where knowledge that the repeated group can match
1303        nothing is needed in order to break the loop.
1304    
1305    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1306        exec(), but without supplying a callout function, matching went wrong.
1307    
1308    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1309        leak if the size of the offset vector was greater than 30. When the vector
1310        is smaller, the saved offsets during recursion go onto a local stack
1311        vector, but for larger vectors malloc() is used. It was failing to free
1312        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1313        error, in fact).
1314    
1315    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1316        heapframe that is used only when UTF-8 support is enabled. This caused no
1317        problem, but was untidy.
1318    
1319    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1320        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1321        included within another project.
1322    
1323    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1324        slightly modified by me:
1325    
1326          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1327              not building pcregrep.
1328    
1329          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1330              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1331    
1332    25. Forward references, both numeric and by name, in patterns that made use of
1333        duplicate group numbers, could behave incorrectly or give incorrect errors,
1334        because when scanning forward to find the reference group, PCRE was not
1335        taking into account the duplicate group numbers. A pattern such as
1336        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1337    
1338    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1339        the feature of a custom pointer more persuasive (as requested by a user).
1340    
1341    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1342        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1343        pre-defined.
1344    
1345    28. Added support for (*UTF8) at the start of a pattern.
1346    
1347    29. Arrange for flags added by the "release type" setting in CMake to be shown
1348        in the configuration summary.
1349    
1350    
1351    Version 7.8 05-Sep-08
1352    ---------------------
1353    
1354    1.  Replaced UCP searching code with optimized version as implemented for Ad
1355        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1356        stage table and inline lookup instead of a function, giving speed ups of 2
1357        to 5 times on some simple patterns that I tested. Permission was given to
1358        distribute the MultiStage2.py script that generates the tables (it's not in
1359        the tarball, but is in the Subversion repository).
1360    
1361    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1362        scripts.
1363    
1364    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1365        a group with a zero qualifier. The result of the study could be incorrect,
1366        or the function might crash, depending on the pattern.
1367    
1368    4.  Caseless matching was not working for non-ASCII characters in back
1369        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1370        It now works when Unicode Property Support is available.
1371    
1372    5.  In pcretest, an escape such as \x{de} in the data was always generating
1373        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1374        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1375        truncation.
1376    
1377    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1378    
1379    7.  Added two (int) casts to pcregrep when printing the difference of two
1380        pointers, in case they are 64-bit values.
1381    
1382    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1383        test 2 if it fails.
1384    
1385    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1386        and a #define of that name to empty if it is not externally set. This is to
1387        allow users of MSVC to set it if necessary.
1388    
1389    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1390        the convenience functions in the pcre_get.c source file.
1391    
1392    11. An option change at the start of a pattern that had top-level alternatives
1393        could cause overwriting and/or a crash. This command provoked a crash in
1394        some environments:
1395    
1396          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1397    
1398        This potential security problem was recorded as CVE-2008-2371.
1399    
1400    12. For a pattern where the match had to start at the beginning or immediately
1401        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1402        pcre_dfa_exec() could read past the end of the passed subject if there was
1403        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1404        pcretest so that it places the subject at the end of its malloc-ed buffer.
1405    
1406    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1407        exec() might read past the end of the data buffer in UTF-8 mode.
1408    
1409    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1410        the data contained the byte 0x85 as part of a UTF-8 character within its
1411        first line. This applied both to normal and DFA matching.
1412    
1413    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1414        /^[^d]*?$/8 failed to match "abc".
1415    
1416    16. Added a missing copyright notice to pcrecpp_internal.h.
1417    
1418    17. Make it more clear in the documentation that values returned from
1419        pcre_exec() in ovector are byte offsets, not character counts.
1420    
1421    18. Tidied a few places to stop certain compilers from issuing warnings.
1422    
1423    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1424        supplied by Stefan Weber. I made a further small update for 7.8 because
1425        there is a change of source arrangements: the pcre_searchfuncs.c module is
1426        replaced by pcre_ucd.c.
1427    
1428    
1429    Version 7.7 07-May-08
1430  ---------------------  ---------------------
1431    
1432  1.  Applied Craig's patch to sort out a long long problem: "If we can't convert  1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1433      a string to a long long, pretend we don't even have a long long." This is      a string to a long long, pretend we don't even have a long long." This is
1434      done by checking for the strtoq, strtoll, and _strtoi64 functions.      done by checking for the strtoq, strtoll, and _strtoi64 functions.
1435    
1436  2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with  2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1437      pre-7.6 versions, which defined a global no_arg variable instead of putting      pre-7.6 versions, which defined a global no_arg variable instead of putting
1438      it in the RE class.      it in the RE class. (See also #8 below.)
1439    
1440  3.  Remove a line of dead code, identified by coverity and reported by Nuno  3.  Remove a line of dead code, identified by coverity and reported by Nuno
1441      Lopes.      Lopes.
1442    
1443  4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:  4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1444    
1445      (1) The include/exclude patterns were being applied to the whole pathnames      (1) The include/exclude patterns were being applied to the whole pathnames
1446          of files, instead of just to the final components.          of files, instead of just to the final components.
1447    
1448      (2) If there was more than one level of directory, the subdirectories were      (2) If there was more than one level of directory, the subdirectories were
1449          skipped unless they satisfied the include/exclude conditions. This is          skipped unless they satisfied the include/exclude conditions. This is
1450          inconsistent with GNU grep (and could even be seen as contrary to the          inconsistent with GNU grep (and could even be seen as contrary to the
1451          pcregrep specification - which I improved to make it absolutely clear).          pcregrep specification - which I improved to make it absolutely clear).
1452          The action now is always to scan all levels of directory, and just          The action now is always to scan all levels of directory, and just
1453          apply the include/exclude patterns to regular files.          apply the include/exclude patterns to regular files.
1454    
1455  5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used  5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1456      --exclude_dir in the tests to avoid scanning .svn directories.      --exclude_dir in the tests to avoid scanning .svn directories.
1457    
1458  6.  Applied Craig's patch to the QuoteMeta function so that it escapes the  6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1459      NUL character as backslash + 0 rather than backslash + NUL, because PCRE      NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1460      doesn't support NULs in patterns.      doesn't support NULs in patterns.
1461    
1462    7.  Added some missing "const"s to declarations of static tables in
1463        pcre_compile.c and pcre_dfa_exec.c.
1464    
1465    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1466        caused by fix #2  above. (Subsequently also a second patch to fix the
1467        first patch. And a third patch - this was a messy problem.)
1468    
1469    9.  Applied Craig's patch to remove the use of push_back().
1470    
1471    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1472        matching function regexec().
1473    
1474    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1475        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1476        references. PCRE supports relative numbers with this syntax (I don't think
1477        Oniguruma does).
1478    
1479    12. Previously, a group with a zero repeat such as (...){0} was completely
1480        omitted from the compiled regex. However, this means that if the group
1481        was called as a subroutine from elsewhere in the pattern, things went wrong
1482        (an internal error was given). Such groups are now left in the compiled
1483        pattern, with a new opcode that causes them to be skipped at execution
1484        time.
1485    
1486    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1487        to the way PCRE behaves:
1488    
1489        (a) A lone ] character is dis-allowed (Perl treats it as data).
1490    
1491        (b) A back reference to an unmatched subpattern matches an empty string
1492            (Perl fails the current match path).
1493    
1494        (c) A data ] in a character class must be notated as \] because if the
1495            first data character in a class is ], it defines an empty class. (In
1496            Perl it is not possible to have an empty class.) The empty class []
1497            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1498            The negative empty class [^] matches any one character, independently
1499            of the DOTALL setting.
1500    
1501    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1502        non-existent subpattern following a character class starting with ']' and
1503        containing () gave an internal compiling error instead of "reference to
1504        non-existent subpattern". Fortunately, when the pattern did exist, the
1505        compiled code was correct. (When scanning forwards to check for the
1506        existencd of the subpattern, it was treating the data ']' as terminating
1507        the class, so got the count wrong. When actually compiling, the reference
1508        was subsequently set up correctly.)
1509    
1510    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1511        it was being rejected as not supported by pcre_dfa_exec(), even though
1512        other assertions are supported. I have made pcre_dfa_exec() support
1513        (*FAIL).
1514    
1515    16. The implementation of 13c above involved the invention of a new opcode,
1516        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1517        cannot be changed at match time, I realized I could make a small
1518        improvement to matching performance by compiling OP_ALLANY instead of
1519        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1520        on the OP_ANY path.
1521    
1522    17. Compiling pcretest on Windows with readline support failed without the
1523        following two fixes: (1) Make the unistd.h include conditional on
1524        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1525    
1526    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1527        ncurses library to be included for pcretest when ReadLine support is
1528        requested, but also to allow for it to be overridden. This patch came from
1529        Daniel Bergström.
1530    
1531    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1532        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1533        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1534        spotting this.
1535    
1536    
1537  Version 7.6 28-Jan-08  Version 7.6 28-Jan-08
1538  ---------------------  ---------------------

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