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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.3 05-Jul-07  Version 8.31
5    -----------------------------
7    1.  Fixing a wrong JIT test case and some compiler warnings.
9    2.  Removed a bashism from the RunTest script.
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)".
15    4.  Partial matching support is added to the JIT compiler.
17    5.  Fixed several bugs concerned with partial matching of items that consist
18        of more than one character:
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.
24        (b) \R did not give a hard partial match if \r was found at the end of the
25            subject.
27        (c) \X did not give a hard partial match after matching one or more
28            characters at the end of the subject.
30        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
31            a partial match for the string "\r".
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.
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.
40    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
41        or /S+[+] with a digit between 1 and 7.
43    8.  OP_NOT now supports any UTF character not just single-byte ones.
45    9.  (*MARK) control verb is now supported by the JIT compiler.
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.)
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.
58    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
59        call.
61    14. As documented, (*COMMIT) is now confined to within a positive assertion.
63    15. It is now possible to link pcretest with libedit as an alternative to
64        libreadline.
66    16. (*COMMIT) control verb is now supported by the JIT compiler.
68    17. The Unicode data tables have been updated to Unicode 6.1.0.
70    18. Added --file-list option to pcregrep.
72    19. Added binary file support to pcregrep, including the -a, --binary-files,
73        -I, and --text options.
75    20. The madvise function is renamed for posix_madvise for QNX compatibility
76        reasons. Fixed by Giuseppe D'Angelo.
78    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
80    22. Changed the option for creating symbolic links for 16-bit man pages from
81        -s to -sf so that re-installing does not cause issues.
83    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
85    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
86        matches in certain environments (the workspace was not being correctly
87        retained). Also added to pcre_dfa_exec() a simple plausibility check on
88        some of the workspace data at the beginning of a restart.
90    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
91        was not doing so when it should - probably a typo introduced by SVN 528
92        (change 8.10/14).
94    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
95        \w+ when the character tables indicated that \x{c4} was a word character.
96        There were several related cases, all because the tests for doing a table
97        lookup were testing for characters less than 127 instead of 255.
99    27. If a pattern contains capturing parentheses that are not used in a match,
100        their slots in the ovector are set to -1. For those that are higher than
101        any matched groups, this happens at the end of processing. In the case when
102        there were back references that the ovector was too small to contain
103        (causing temporary malloc'd memory to be used during matching), and the
104        highest capturing number was not used, memory off the end of the ovector
105        was incorrectly being set to -1. (It was using the size of the temporary
106        memory instead of the true size.)
108    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
109        ovector size, it uses memory at the end of the block that it has got.
111    29. Check for an overlong MARK name and give an error at compile time. The
112        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
114    30. JIT compiler update.
116    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
117        Rill for the patch.
120    Version 8.30 04-February-2012
121    -----------------------------
123    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
124        name is defined in ctype.h.
126    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
127        only in quite long subpatterns.
129    3.  Removed the function pcre_info(), which has been obsolete and deprecated
130        since it was replaced by pcre_fullinfo() in February 2000.
132    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
133        match a (*MARK), and the match failed at the start of the subject, a
134        reference to memory before the start of the subject could occur. This bug
135        was introduced by fix 17 of release 8.21.
137    5.  A reference to an unset group with zero minimum repetition was giving
138        totally wrong answers (in non-JavaScript-compatibility mode). For example,
139        /(another)?(\1?)test/ matched against "hello world test". This bug was
140        introduced in release 8.13.
142    6.  Add support for 16-bit character strings (a large amount of work involving
143        many changes and refactorings).
145    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
146        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
147        from a file.
149    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
150        rounding is not applied in this particular case).
152    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
153        if they appear, or are escaped, in patterns.
155    10. Get rid of a number of -Wunused-but-set-variable warnings.
157    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
158        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
159        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
160        also returns the mark "x". This bug applied to capturing parentheses,
161        non-capturing parentheses, and atomic parentheses. It also applied to some
162        assertions.
164    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
165        information out of configure.ac instead of relying on pcre.h.generic, which
166        is not stored in the repository.
168    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
169        -lreadline.
171    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
173    15. Applied Graycode's patch to put the top-level frame on the stack rather
174        than the heap when not using the stack for recursion. This gives a
175        performance improvement in many cases when recursion is not deep.
177    16. Experimental code added to "pcretest -C" to output the stack frame size.
180    Version 8.21 12-Dec-2011
181    ------------------------
183    1.  Updating the JIT compiler.
185    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
186        are added as well.
188    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
189        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
190        calling _pcre_jit_exec. Some extra comments are added.
192    4.  (*MARK) settings inside atomic groups that do not contain any capturing
193        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
194        was introduced by change 18 for 8.20.
196    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
197        ECMA-262 standard.
199    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
200        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
201        This bug was probably introduced by change 9 of 8.13.
203    7.  While fixing 6 above, I noticed that a number of other items were being
204        incorrectly rejected as "not fixed length". This arose partly because newer
205        opcodes had not been added to the fixed-length checking code. I have (a)
206        corrected the bug and added tests for these items, and (b) arranged for an
207        error to occur if an unknown opcode is encountered while checking for fixed
208        length instead of just assuming "not fixed length". The items that were
209        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
210        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
211        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
213    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
214        being incorrectly compiled and would have given unpredicatble results.
216    9.  A possessively repeated subpattern with minimum repeat count greater than
217        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
218        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
219        the first (A) could occur when it should not.
221    10. Add a cast and remove a redundant test from the code.
223    11. JIT should use pcre_malloc/pcre_free for allocation.
225    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
226        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
227        is anything other than /usr, -L is still shown).
229    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
231    14. Perl does not support \N without a following name in a [] class; PCRE now
232        also gives an error.
234    15. If a forward reference was repeated with an upper limit of around 2000,
235        it caused the error "internal error: overran compiling workspace". The
236        maximum number of forward references (including repeats) was limited by the
237        internal workspace, and dependent on the LINK_SIZE. The code has been
238        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
239        the default depends on LINK_SIZE. There is a new upper limit (for safety)
240        of around 200,000 forward references. While doing this, I also speeded up
241        the filling in of repeated forward references.
243    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
244        incorrectly expecting the subject to contain another "a" after the start.
246    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
247        in the match, the SKIP should be ignored. This was not happening; instead
248        the SKIP was being treated as NOMATCH. For patterns such as
249        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
250        tested.
252    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
253        now much more compatible with Perl, in particular in cases where the result
254        is a non-match for a non-anchored pattern. For example, if
255        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
256        "m", where previously it did not return a name. A side effect of this
257        change is that for partial matches, the last encountered mark name is
258        returned, as for non matches. A number of tests that were previously not
259        Perl-compatible have been moved into the Perl-compatible test files. The
260        refactoring has had the pleasing side effect of removing one argument from
261        the match() function, thus reducing its stack requirements.
263    19. If the /S+ option was used in pcretest to study a pattern using JIT,
264        subsequent uses of /S (without +) incorrectly behaved like /S+.
266    21. Retrieve executable code size support for the JIT compiler and fixing
267        some warnings.
269    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
270        not work when the shorter character appeared right at the end of the
271        subject string.
273    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
274        systems.
276    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
277        output it when the /M option is used in pcretest.
279    25. The CheckMan script was not being included in the distribution. Also, added
280        an explicit "perl" to run Perl scripts from the PrepareRelease script
281        because this is reportedly needed in Windows.
283    26. If study data was being save in a file and studying had not found a set of
284        "starts with" bytes for the pattern, the data written to the file (though
285        never used) was taken from uninitialized memory and so caused valgrind to
286        complain.
288    27. Updated RunTest.bat as provided by Sheri Pierce.
290    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
292    29. Computation of memory usage for the table of capturing group names was
293        giving an unnecessarily large value.
296    Version 8.20 21-Oct-2011
297    ------------------------
299    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
300        a POSIX class. After further experiments with Perl, which convinced me that
301        Perl has bugs and confusions, a closing square bracket is no longer allowed
302        in a POSIX name. This bug also affected patterns with classes that started
303        with full stops.
305    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
306        captured substring, but while checking the failing first alternative,
307        substring 1 is temporarily captured. If the output vector supplied to
308        pcre_exec() was not big enough for this capture, the yield of the function
309        was still zero ("insufficient space for captured substrings"). This cannot
310        be totally fixed without adding another stack variable, which seems a lot
311        of expense for a edge case. However, I have improved the situation in cases
312        such as /(a)(b)x|abc/ matched against "abc", where the return code
313        indicates that fewer than the maximum number of slots in the ovector have
314        been set.
316    3.  Related to (2) above: when there are more back references in a pattern than
317        slots in the output vector, pcre_exec() uses temporary memory during
318        matching, and copies in the captures as far as possible afterwards. It was
319        using the entire output vector, but this conflicts with the specification
320        that only 2/3 is used for passing back captured substrings. Now it uses
321        only the first 2/3, for compatibility. This is, of course, another edge
322        case.
324    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
325        main code base, and can be used by building with --enable-jit. When this is
326        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
327        runtime --no-jit option is given.
329    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
330        ovector, the return from the function was zero, implying that there were
331        other matches that did not fit. The correct "exactly full" value is now
332        returned.
334    6.  If a subpattern that was called recursively or as a subroutine contained
335        (*PRUNE) or any other control that caused it to give a non-standard return,
336        invalid errors such as "Error -26 (nested recursion at the same subject
337        position)" or even infinite loops could occur.
339    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
340        computing the minimum length on reaching *ACCEPT, and so ended up with the
341        wrong value of 1 rather than 0. Further investigation indicates that
342        computing a minimum subject length in the presence of *ACCEPT is difficult
343        (think back references, subroutine calls), and so I have changed the code
344        so that no minimum is registered for a pattern that contains *ACCEPT.
346    8.  If (*THEN) was present in the first (true) branch of a conditional group,
347        it was not handled as intended. [But see 16 below.]
349    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
350        Sheri Pierce.
352    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
353        the first byte in a match must be "a".
355    11. Change 17 for 8.13 increased the recursion depth for patterns like
356        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
357        pattern contains any instances of (*THEN). If it does not, the old
358        optimizations are restored. It would be nice to do this on a per-group
359        basis, but at the moment that is not feasible.
361    12. In some environments, the output of pcretest -C is CRLF terminated. This
362        broke RunTest's code that checks for the link size. A single white space
363        character after the value is now allowed for.
365    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
366        For "fr", it uses the Windows-specific input and output files.
368    14. If (*THEN) appeared in a group that was called recursively or as a
369        subroutine, it did not work as intended. [But see next item.]
371    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
372        pattern fragments (but not containing any | characters). If A and B are
373        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
374        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
375        D. In other words, Perl considers parentheses that do not contain any |
376        characters to be part of a surrounding alternative, whereas PCRE was
377        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
378        differently. PCRE now behaves in the same way as Perl, except in the case
379        of subroutine/recursion calls such as (?1) which have in any case always
380        been different (but PCRE had them first :-).
382    16. Related to 15 above: Perl does not treat the | in a conditional group as
383        creating alternatives. Such a group is treated in the same way as an
384        ordinary group without any | characters when processing (*THEN). PCRE has
385        been changed to match Perl's behaviour.
387    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
388        RunGrepTest script failed.
390    18. Change 22 for version 13 caused atomic groups to use more stack. This is
391        inevitable for groups that contain captures, but it can lead to a lot of
392        stack use in large patterns. The old behaviour has been restored for atomic
393        groups that do not contain any capturing parentheses.
395    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
396        suppress the check for a minimum subject length at run time. (If it was
397        given to pcre_exec() or pcre_dfa_exec() it did work.)
399    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
400        fail to work when decoding hex characters in data strings in EBCDIC
401        environments.
403    21. It appears that in at least one Mac OS environment, the isxdigit() function
404        is implemented as a macro that evaluates to its argument more than once,
405        contravening the C 90 Standard (I haven't checked a later standard). There
406        was an instance in pcretest which caused it to go wrong when processing
407        \x{...} escapes in subject strings. The has been rewritten to avoid using
408        things like p++ in the argument of isxdigit().
411    Version 8.13 16-Aug-2011
412    ------------------------
414    1.  The Unicode data tables have been updated to Unicode 6.0.0.
416    2.  Two minor typos in pcre_internal.h have been fixed.
418    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
419        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
420        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
422    4.  There were a number of related bugs in the code for matching backrefences
423        caselessly in UTF-8 mode when codes for the characters concerned were
424        different numbers of bytes. For example, U+023A and U+2C65 are an upper
425        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
426        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
427        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
428        2-byte code at the end of the subject (it thought there wasn't enough data
429        left).
431    5.  Comprehensive information about what went wrong is now returned by
432        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
433        as the output vector has at least 2 elements. The offset of the start of
434        the failing character and a reason code are placed in the vector.
436    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
437        now returned is for the first byte of the failing character, instead of the
438        last byte inspected. This is an incompatible change, but I hope it is small
439        enough not to be a problem. It makes the returned offset consistent with
440        pcre_exec() and pcre_dfa_exec().
442    7.  pcretest now gives a text phrase as well as the error number when
443        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
444        failure, the offset and reason code are output.
446    8.  When \R was used with a maximizing quantifier it failed to skip backwards
447        over a \r\n pair if the subsequent match failed. Instead, it just skipped
448        back over a single character (\n). This seems wrong (because it treated the
449        two characters as a single entity when going forwards), conflicts with the
450        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
451        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
452        has been changed.
454    9.  Some internal refactoring has changed the processing so that the handling
455        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
456        time (the PCRE_DOTALL option was changed this way some time ago: version
457        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
458        which was always a bit of a fudge. It also means that there is one less
459        argument for the match() function, which reduces its stack requirements
460        slightly. This change also fixes an incompatibility with Perl: the pattern
461        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
463    10. More internal refactoring has drastically reduced the number of recursive
464        calls to match() for possessively repeated groups such as (abc)++ when
465        using pcre_exec().
467    11. While implementing 10, a number of bugs in the handling of groups were
468        discovered and fixed:
470        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
471        (a|)*(?1) gave a compile-time internal error.
472        ((a|)+)+  did not notice that the outer group could match an empty string.
473        (^a|^)+   was not marked as anchored.
474        (.*a|.*)+ was not marked as matching at start or after a newline.
476    12. Yet more internal refactoring has removed another argument from the match()
477        function. Special calls to this function are now indicated by setting a
478        value in a variable in the "match data" data block.
480    13. Be more explicit in pcre_study() instead of relying on "default" for
481        opcodes that mean there is no starting character; this means that when new
482        ones are added and accidentally left out of pcre_study(), testing should
483        pick them up.
485    14. The -s option of pcretest has been documented for ages as being an old
486        synonym of -m (show memory usage). I have changed it to mean "force study
487        for every regex", that is, assume /S for every regex. This is similar to -i
488        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
489        using it. It makes it easier to run collections of tests with and without
490        study enabled, and thereby test pcre_study() more easily. All the standard
491        tests are now run with and without -s (but some patterns can be marked as
492        "never study" - see 20 below).
494    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
495        restoration of the capturing data to the outer values was not happening
496        correctly.
498    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
499        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
500        pattern had matched an empty string, and so incorrectly returned a no
501        match.
503    17. There was optimizing code for the last branch of non-capturing parentheses,
504        and also for the obeyed branch of a conditional subexpression, which used
505        tail recursion to cut down on stack usage. Unfortunately, now that there is
506        the possibility of (*THEN) occurring in these branches, tail recursion is
507        no longer possible because the return has to be checked for (*THEN). These
508        two optimizations have therefore been removed. [But see 8.20/11 above.]
510    18. If a pattern containing \R was studied, it was assumed that \R always
511        matched two bytes, thus causing the minimum subject length to be
512        incorrectly computed because \R can also match just one byte.
514    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
515        was incorrectly computed.
517    20. If /S is present twice on a test pattern in pcretest input, it now
518        *disables* studying, thereby overriding the use of -s on the command line
519        (see 14 above). This is necessary for one or two tests to keep the output
520        identical in both cases.
522    21. When (*ACCEPT) was used in an assertion that matched an empty string and
523        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
525    22. When an atomic group that contained a capturing parenthesis was
526        successfully matched, but the branch in which it appeared failed, the
527        capturing was not being forgotten if a higher numbered group was later
528        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
529        group 1 to "a", when in fact it should be unset. This applied to multi-
530        branched capturing and non-capturing groups, repeated or not, and also to
531        positive assertions (capturing in negative assertions does not happen
532        in PCRE) and also to nested atomic groups.
534    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
535        subject after a captured substring, to make it easier to tell which of a
536        number of identical substrings has been captured.
538    24. The way atomic groups are processed by pcre_exec() has been changed so that
539        if they are repeated, backtracking one repetition now resets captured
540        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
541        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
542        "aaa". Previously, it would have been "a". As part of this code
543        refactoring, the way recursive calls are handled has also been changed.
545    25. If an assertion condition captured any substrings, they were not passed
546        back unless some other capturing happened later. For example, if
547        (?(?=(a))a) was matched against "a", no capturing was returned.
549    26. When studying a pattern that contained subroutine calls or assertions,
550        the code for finding the minimum length of a possible match was handling
551        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
552        group 1 called group 2 while simultaneously a separate group 2 called group
553        1). A stack overflow occurred in this case. I have fixed this by limiting
554        the recursion depth to 10.
556    27. Updated RunTest.bat in the distribution to the version supplied by Tom
557        Fortmann. This supports explicit test numbers on the command line, and has
558        argument validation and error reporting.
560    28. An instance of \X with an unlimited repeat could fail if at any point the
561        first character it looked at was a mark character.
563    29. Some minor code refactoring concerning Unicode properties and scripts
564        should reduce the stack requirement of match() slightly.
566    30. Added the '=' option to pcretest to check the setting of unused capturing
567        slots at the end of the pattern, which are documented as being -1, but are
568        not included in the return count.
570    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
571        compiled something random. Now it gives a compile-time error (as does
572        Perl).
574    32. A *MARK encountered during the processing of a positive assertion is now
575        recorded and passed back (compatible with Perl).
577    33. If --only-matching or --colour was set on a pcregrep call whose pattern
578        had alternative anchored branches, the search for a second match in a line
579        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
580        matched the line "0102" twice. The same bug affected patterns that started
581        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
582        twice.
584    34. Previously, PCRE did not allow quantification of assertions. However, Perl
585        does, and because of capturing effects, quantifying parenthesized
586        assertions may at times be useful. Quantifiers are now allowed for
587        parenthesized assertions.
589    35. A minor code tidy in pcre_compile() when checking options for \R usage.
591    36. \g was being checked for fancy things in a character class, when it should
592        just be a literal "g".
594    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
595        appearance of a nested POSIX class supersedes an apparent external class.
596        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
597        unescaped square brackets may also appear as part of class names. For
598        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
599        more like Perl. (But see 8.20/1 above.)
601    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
602        was because it thought it was \N{name}, which is not supported).
604    39. Add minix to OS list not supporting the -S option in pcretest.
606    40. PCRE tries to detect cases of infinite recursion at compile time, but it
607        cannot analyze patterns in sufficient detail to catch mutual recursions
608        such as ((?1))((?2)). There is now a runtime test that gives an error if a
609        subgroup is called recursively as a subpattern for a second time at the
610        same position in the subject string. In previous releases this might have
611        been caught by the recursion limit, or it might have run out of stack.
613    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
614        happen only once. PCRE was, however incorrectly giving a compile time error
615        "recursive call could loop indefinitely" because it cannot analyze the
616        pattern in sufficient detail. The compile time test no longer happens when
617        PCRE is compiling a conditional subpattern, but actual runaway loops are
618        now caught at runtime (see 40 above).
620    42. It seems that Perl allows any characters other than a closing parenthesis
621        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
622        has been changed to be the same.
624    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
625        as not to get warnings when autogen.sh is called. Also changed
626        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
628    44. To help people who use pcregrep to scan files containing exceedingly long
629        lines, the following changes have been made:
631        (a) The default value of the buffer size parameter has been increased from
632            8K to 20K. (The actual buffer used is three times this size.)
634        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
635            PCRE is built.
637        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
638            to be set at run time.
640        (d) Numerical values in pcregrep options can be followed by K or M, for
641            example --buffer-size=50K.
643        (e) If a line being scanned overflows pcregrep's buffer, an error is now
644            given and the return code is set to 2.
646    45. Add a pointer to the latest mark to the callout data block.
648    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
649        partial match of an empty string instead of no match. This was specific to
650        the use of ".".
652    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
653        complete match instead of a partial match. This bug was dependent on both
654        the PCRE_UTF8 and PCRE_DOTALL options being set.
656    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
657        starting byte set, because \b was not being ignored.
660    Version 8.12 15-Jan-2011
661    ------------------------
663    1.  Fixed some typos in the markup of the man pages, and wrote a script that
664        checks for such things as part of the documentation building process.
666    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
667        --match-limit and --recursion-limit options (added for 8.11). In
668        particular, this made one of the standard tests fail. (The integer value
669        went into the wrong half of a long int.)
671    3.  If the --colour option was given to pcregrep with -v (invert match), it
672        did strange things, either producing crazy output, or crashing. It should,
673        of course, ignore a request for colour when reporting lines that do not
674        match.
676    4.  Another pcregrep bug caused similar problems if --colour was specified with
677        -M (multiline) and the pattern match finished with a line ending.
679    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
680        matched in multiline mode, the following line was shown as part of the
681        match. This seems wrong, so I have changed it.
683    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
684        the check for further matches in the same line (so they could be coloured)
685        to overrun the end of the current line. If another match was found, it was
686        incorrectly shown (and then shown again when found in the next line).
688    7.  If pcregrep was compiled under Windows, there was a reference to the
689        function pcregrep_exit() before it was defined. I am assuming this was
690        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
691        reported by a user. I've moved the definition above the reference.
694    Version 8.11 10-Dec-2010
695    ------------------------
697    1.  (*THEN) was not working properly if there were untried alternatives prior
698        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
699        backtracked to try for "b" instead of moving to the next alternative branch
700        at the same level (in this case, to look for "c"). The Perl documentation
701        is clear that when (*THEN) is backtracked onto, it goes to the "next
702        alternative in the innermost enclosing group".
704    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
705        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
706        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
707        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
708        (*THEN).
710    3.  If \s appeared in a character class, it removed the VT character from
711        the class, even if it had been included by some previous item, for example
712        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
713        of \s, but is part of the POSIX "space" class.)
715    4.  A partial match never returns an empty string (because you can always
716        match an empty string at the end of the subject); however the checking for
717        an empty string was starting at the "start of match" point. This has been
718        changed to the "earliest inspected character" point, because the returned
719        data for a partial match starts at this character. This means that, for
720        example, /(?<=abc)def/ gives a partial match for the subject "abc"
721        (previously it gave "no match").
723    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
724        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
725        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
726        has an implication that the given string is incomplete (because a partial
727        match is preferred over a full match). For this reason, these items now
728        give a partial match in this situation. [Aside: previously, the one case
729        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
730        match rather than a full match, which was wrong by the old rules, but is
731        now correct.]
733    6.  There was a bug in the handling of #-introduced comments, recognized when
734        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
735        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
736        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
737        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
738        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
739        places in pcre_compile().
741    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
742        comments when looking ahead for named forward references to subpatterns,
743        the only newline sequence it recognized was NL. It now handles newlines
744        according to the set newline convention.
746    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
747        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
748        cater for a lack of strerror(). These oversights have been fixed.
750    9.  Added --match-limit and --recursion-limit to pcregrep.
752    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
754    11. When the -o option was used, pcregrep was setting a return code of 1, even
755        when matches were found, and --line-buffered was not being honoured.
757    12. Added an optional parentheses number to the -o and --only-matching options
758        of pcregrep.
760    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
761        can match an empty string. The code to do it in pcretest and pcredemo
762        needed fixing:
764        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
765            only one byte after an empty string match just before CRLF (this case
766            just got forgotten; "any" and "anycrlf" were OK).
768        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
769            mode when an empty string match preceded an ASCII character followed by
770            a non-ASCII character. (The code for advancing by one character rather
771            than one byte was nonsense.)
773        (c) The pcredemo.c sample program did not have any code at all to handle
774            the cases when CRLF is a valid newline sequence.
776    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
777        as a starting offset was within the subject string. There is now a new
778        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
779        negative or greater than the length of the string. In order to test this,
780        pcretest is extended to allow the setting of negative starting offsets.
782    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
783        starting offset points to the beginning of a UTF-8 character was
784        unnecessarily clumsy. I tidied it up.
786    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
787        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
789    17. Nobody had reported that the --include_dir option, which was added in
790        release 7.7 should have been called --include-dir (hyphen, not underscore)
791        for compatibility with GNU grep. I have changed it to --include-dir, but
792        left --include_dir as an undocumented synonym, and the same for
793        --exclude-dir, though that is not available in GNU grep, at least as of
794        release 2.5.4.
796    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
797        characters from a string of bytes) have been redefined so as not to use
798        loops, in order to improve performance in some environments. At the same
799        time, I abstracted some of the common code into auxiliary macros to save
800        repetition (this should not affect the compiled code).
802    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
803        compile-time error is now given if \c is not followed by an ASCII
804        character, that is, a byte less than 128. (In EBCDIC mode, the code is
805        different, and any byte value is allowed.)
807    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
808        START_OPTIMIZE option, which is now allowed at compile time - but just
809        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
810        to pcregrep and other applications that have no direct access to PCRE
811        options. The new /Y option in pcretest sets this option when calling
812        pcre_compile().
814    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
815        back references. Groups containing recursive back references were forced to
816        be atomic by that change, but in the case of named groups, the amount of
817        memory required was incorrectly computed, leading to "Failed: internal
818        error: code overflow". This has been fixed.
820    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
821        pcretest.c, to avoid build problems in some Borland environments.
824    Version 8.10 25-Jun-2010
825    ------------------------
827    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
828        THEN.
830    2.  (*ACCEPT) was not working when inside an atomic group.
832    3.  Inside a character class, \B is treated as a literal by default, but
833        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
834        causes the error). The code is unchanged, but I tidied the documentation.
836    4.  Inside a character class, PCRE always treated \R and \X as literals,
837        whereas Perl faults them if its -w option is set. I have changed PCRE so
838        that it faults them when PCRE_EXTRA is set.
840    5.  Added support for \N, which always matches any character other than
841        newline. (It is the same as "." when PCRE_DOTALL is not set.)
843    6.  When compiling pcregrep with newer versions of gcc which may have
844        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
845        declared with attribute warn_unused_result" were given. Just casting the
846        result to (void) does not stop the warnings; a more elaborate fudge is
847        needed. I've used a macro to implement this.
849    7.  Minor change to pcretest.c to avoid a compiler warning.
851    8.  Added four artifical Unicode properties to help with an option to make
852        \s etc use properties (see next item). The new properties are: Xan
853        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
855    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
856        use Unicode properties. (*UCP) at the start of a pattern can be used to set
857        this option. Modified pcretest to add /W to test this facility. Added
858        REG_UCP to make it available via the POSIX interface.
860    10. Added --line-buffered to pcregrep.
862    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
863        studied, and the match started with a letter with a code point greater than
864        127 whose first byte was different to the first byte of the other case of
865        the letter, the other case of this starting letter was not recognized
866        (#976).
868    12. If a pattern that was studied started with a repeated Unicode property
869        test, for example, \p{Nd}+, there was the theoretical possibility of
870        setting up an incorrect bitmap of starting bytes, but fortunately it could
871        not have actually happened in practice until change 8 above was made (it
872        added property types that matched character-matching opcodes).
874    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
875        possible starting bytes for non-anchored patterns.
877    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
878        \R, and also a number of cases that involve Unicode properties, both
879        explicit and implicit when PCRE_UCP is set.
881    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
882        input, it could crash or give wrong results if characters with values
883        greater than 0xc0 were present in the subject string. (Detail: it assumed
884        UTF-8 input when processing these items.)
886    16. Added a lot of (int) casts to avoid compiler warnings in systems where
887        size_t is 64-bit (#991).
889    17. Added a check for running out of memory when PCRE is compiled with
890        --disable-stack-for-recursion (#990).
892    18. If the last data line in a file for pcretest does not have a newline on
893        the end, a newline was missing in the output.
895    19. The default pcre_chartables.c file recognizes only ASCII characters (values
896        less than 128) in its various bitmaps. However, there is a facility for
897        generating tables according to the current locale when PCRE is compiled. It
898        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
899        characters, are recognized by isspace() and therefore were getting set in
900        these tables, and indeed these tables seem to approximate to ISO 8859. This
901        caused a problem in UTF-8 mode when pcre_study() was used to create a list
902        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
903        which of course cannot start UTF-8 characters. I have changed the code so
904        that only real ASCII characters (less than 128) and the correct starting
905        bytes for UTF-8 encodings are set for characters greater than 127 when in
906        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
907        altogether.)
909    20. Added the /T option to pcretest so as to be able to run tests with non-
910        standard character tables, thus making it possible to include the tests
911        used for 19 above in the standard set of tests.
913    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
914        reference to a subpattern the other side of a comment that contains an
915        opening parenthesis caused either an internal compiling error, or a
916        reference to the wrong subpattern.
919    Version 8.02 19-Mar-2010
920    ------------------------
922    1.  The Unicode data tables have been updated to Unicode 5.2.0.
924    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
925        configured.
927    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
928        original author of that file, following a query about its status.
930    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
931        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
933    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
934        quantifier applied to a forward-referencing subroutine call, could compile
935        incorrect code or give the error "internal error: previously-checked
936        referenced subpattern not found".
938    6.  Both MS Visual Studio and Symbian OS have problems with initializing
939        variables to point to external functions. For these systems, therefore,
940        pcre_malloc etc. are now initialized to local functions that call the
941        relevant global functions.
943    7.  There were two entries missing in the vectors called coptable and poptable
944        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
945        I've fixed the data, and added a kludgy way of testing at compile time that
946        the lengths are correct (equal to the number of opcodes).
948    8.  Following on from 7, I added a similar kludge to check the length of the
949        eint vector in pcreposix.c.
951    9.  Error texts for pcre_compile() are held as one long string to avoid too
952        much relocation at load time. To find a text, the string is searched,
953        counting zeros. There was no check for running off the end of the string,
954        which could happen if a new error number was added without updating the
955        string.
957    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
959    11. \K was not working if it appeared in an atomic group or in a group that
960        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
961        \K is "not well defined" if used in an assertion. PCRE now accepts it if
962        the assertion is positive, but not if it is negative.
964    12. Change 11 fortuitously reduced the size of the stack frame used in the
965        "match()" function of pcre_exec.c by one pointer. Forthcoming
966        implementation of support for (*MARK) will need an extra pointer on the
967        stack; I have reserved it now, so that the stack frame size does not
968        decrease.
970    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
971        item in branch that calls a recursion is a subroutine call - as in the
972        second branch in the above example - was incorrectly given the compile-
973        time error "recursive call could loop indefinitely" because pcre_compile()
974        was not correctly checking the subroutine for matching a non-empty string.
976    14. The checks for overrunning compiling workspace could trigger after an
977        overrun had occurred. This is a "should never occur" error, but it can be
978        triggered by pathological patterns such as hundreds of nested parentheses.
979        The checks now trigger 100 bytes before the end of the workspace.
981    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
984    Version 8.01 19-Jan-2010
985    ------------------------
987    1.  If a pattern contained a conditional subpattern with only one branch (in
988        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
989        computed the wrong minimum data length (which is of course zero for such
990        subpatterns). This could cause incorrect "no match" results.
992    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
993        the pattern is reset in the first branch, pcre_compile() failed with
994        "internal error: code overflow at offset...". This happened only when
995        the reset was to the original external option setting. (An optimization
996        abstracts leading options settings into an external setting, which was the
997        cause of this.)
999    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1000        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1001        assertion pattern did not match (meaning that the assertion was true), it
1002        was incorrectly treated as false if the SKIP had been reached during the
1003        matching. This also applied to assertions used as conditions.
1005    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1006        assertion subpattern, including such a pattern used as a condition,
1007        unpredictable results occurred, instead of the error return
1010    5.  The C++ GlobalReplace function was not working like Perl for the special
1011        situation when an empty string is matched. It now does the fancy magic
1012        stuff that is necessary.
1014    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1015        removed. (These were left over from very, very early versions of PCRE.)
1017    7.  Some cosmetic changes to the code to make life easier when compiling it
1018        as part of something else:
1020        (a) Change DEBUG to PCRE_DEBUG.
1022        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1023            called "current" as "current_branch", to prevent a collision with the
1024            Linux macro when compiled as a kernel module.
1026        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1027            prevent a collision with the Linux macro when compiled as a kernel
1028            module.
1030    8.  In pcre_compile() there are some checks for integer overflows that used to
1031        cast potentially large values to (double). This has been changed to that
1032        when building, a check for int64_t is made, and if it is found, it is used
1033        instead, thus avoiding the use of floating point arithmetic. (There is no
1034        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1035        double.
1037    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1038        2005 (difference between two addresses compared to an unsigned value).
1040    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1041        custom one, because of the following reported problem in Windows:
1043          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1044              under Win32.
1045          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1046              therefore missing the function definition.
1047          - The compiler thus generates a "C" signature for the test function.
1048          - The linker fails to find the "C" function.
1049          - PCRE fails to configure if asked to do so against libbz2.
1051    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1052        messages were output:
1054          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1055          rerunning libtoolize, to keep the correct libtool macros in-tree.
1056          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1058        I have done both of these things.
1060    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1061        most of the time, it *can* run out if it is given a pattern that contains a
1062        runaway infinite recursion. I updated the discussion in the pcrestack man
1063        page.
1065    13. Now that we have gone to the x.xx style of version numbers, the minor
1066        version may start with zero. Using 08 or 09 is a bad idea because users
1067        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1068        interpreted as invalid octal numbers. I've updated the previous comment in
1069        configure.ac, and also added a check that gives an error if 08 or 09 are
1070        used.
1072    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1073        causing partial matching to fail when the end of the subject matched \W
1074        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1076    15. There were some discrepancies between the declarations in pcre_internal.h
1077        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1078        their definitions. The declarations used "const uschar *" and the
1079        definitions used USPTR. Even though USPTR is normally defined as "const
1080        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1081        reported that: "This difference in casting confuses some C++ compilers, for
1082        example, SunCC recognizes above declarations as different functions and
1083        generates broken code for hbpcre." I have changed the declarations to use
1084        USPTR.
1086    16. GNU libtool is named differently on some systems. The autogen.sh script now
1087        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1088        (FreeBSD).
1090    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1091        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1092        comment: "Figure out how to create a longlong from a string: strtoll and
1093        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1094        instance, but it only takes 2 args instead of 3!"
1096    18. A subtle bug concerned with back references has been fixed by a change of
1097        specification, with a corresponding code fix. A pattern such as
1098        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1099        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1100        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1101        same bug. Such groups have to be quantified to be useful, or contained
1102        inside another quantified group. (If there's no repetition, the reference
1103        can never match.) The problem arises because, having left the group and
1104        moved on to the rest of the pattern, a later failure that backtracks into
1105        the group uses the captured value from the final iteration of the group
1106        rather than the correct earlier one. I have fixed this in PCRE by forcing
1107        any group that contains a reference to itself to be an atomic group; that
1108        is, there cannot be any backtracking into it once it has completed. This is
1109        similar to recursive and subroutine calls.
1112    Version 8.00 19-Oct-09
1113    ----------------------
1115    1.  The table for translating pcre_compile() error codes into POSIX error codes
1116        was out-of-date, and there was no check on the pcre_compile() error code
1117        being within the table. This could lead to an OK return being given in
1118        error.
1120    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1121        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1122        in a Windows environment.
1124    3.  The pcregrep --count option prints the count for each file even when it is
1125        zero, as does GNU grep. However, pcregrep was also printing all files when
1126        --files-with-matches was added. Now, when both options are given, it prints
1127        counts only for those files that have at least one match. (GNU grep just
1128        prints the file name in this circumstance, but including the count seems
1129        more useful - otherwise, why use --count?) Also ensured that the
1130        combination -clh just lists non-zero counts, with no names.
1132    4.  The long form of the pcregrep -F option was incorrectly implemented as
1133        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1134        but it seems right to fix it, and I didn't think it was worth preserving
1135        the old behaviour.
1137    5.  The command line items --regex=pattern and --regexp=pattern were not
1138        recognized by pcregrep, which required --regex pattern or --regexp pattern
1139        (with a space rather than an '='). The man page documented the '=' forms,
1140        which are compatible with GNU grep; these now work.
1142    6.  No libpcreposix.pc file was created for pkg-config; there was just
1143        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1145    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1146        when UCP support is not needed, by modifying the Python script that
1147        generates it from Unicode data files. This should not matter if the module
1148        is correctly used as a library, but I received one complaint about 50K of
1149        unwanted data. My guess is that the person linked everything into his
1150        program rather than using a library. Anyway, it does no harm.
1152    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1153        was a minimum greater than 1 for a wide character in a possessive
1154        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1155        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1156        character. Chaos in the form of incorrect output or a compiling loop could
1157        result.
1159    9.  The restrictions on what a pattern can contain when partial matching is
1160        requested for pcre_exec() have been removed. All patterns can now be
1161        partially matched by this function. In addition, if there are at least two
1162        slots in the offset vector, the offset of the earliest inspected character
1163        for the match and the offset of the end of the subject are set in them when
1164        PCRE_ERROR_PARTIAL is returned.
1166    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1167        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1168        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1169        and may be more useful for multi-segment matching.
1171    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1172        used to be given if ever the end of the subject was reached; now it is
1173        given only if matching could not proceed because another character was
1174        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1175        string "Z", which now yields "no match" instead of "partial match". In the
1176        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1177        final character ended with (*FAIL).
1179    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1180        if the pattern had a "must contain" character that was already found in the
1181        earlier partial match, unless partial matching was again requested. For
1182        example, with the pattern /dog.(body)?/, the "must contain" character is
1183        "g". If the first part-match was for the string "dog", restarting with
1184        "sbody" failed. This bug has been fixed.
1186    13. The string returned by pcre_dfa_exec() after a partial match has been
1187        changed so that it starts at the first inspected character rather than the
1188        first character of the match. This makes a difference only if the pattern
1189        starts with a lookbehind assertion or \b or \B (\K is not supported by
1190        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1191        matching functions compatible, and I think it's the right thing to do.
1193    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1194        so that the demonstration program is easily available in environments where
1195        PCRE has not been installed from source.
1197    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1198        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1199        library.
1201    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1202        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1203        is not the first non-POSIX option to be added. Clearly some people find
1204        these options useful.
1206    17. If a caller to the POSIX matching function regexec() passes a non-zero
1207        value for nmatch with a NULL value for pmatch, the value of
1208        nmatch is forced to zero.
1210    18. RunGrepTest did not have a test for the availability of the -u option of
1211        the diff command, as RunTest does. It now checks in the same way as
1212        RunTest, and also checks for the -b option.
1214    19. If an odd number of negated classes containing just a single character
1215        interposed, within parentheses, between a forward reference to a named
1216        subpattern and the definition of the subpattern, compilation crashed with
1217        an internal error, complaining that it could not find the referenced
1218        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1219        [The bug was that it was starting one character too far in when skipping
1220        over the character class, thus treating the ] as data rather than
1221        terminating the class. This meant it could skip too much.]
1223    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1224        /g option in pcretest when the pattern contains \K, which makes it possible
1225        to have an empty string match not at the start, even when the pattern is
1226        anchored. Updated pcretest and pcredemo to use this option.
1228    21. If the maximum number of capturing subpatterns in a recursion was greater
1229        than the maximum at the outer level, the higher number was returned, but
1230        with unset values at the outer level. The correct (outer level) value is
1231        now given.
1233    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1234        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1235        make it do so. The string so far is captured, making this feature
1236        compatible with Perl.
1238    23. The tests have been re-organized, adding tests 11 and 12, to make it
1239        possible to check the Perl 5.10 features against Perl 5.10.
1241    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1242        pattern matches a fixed length string. PCRE did not allow this; now it
1243        does. Neither allows recursion.
1245    25. I finally figured out how to implement a request to provide the minimum
1246        length of subject string that was needed in order to match a given pattern.
1247        (It was back references and recursion that I had previously got hung up
1248        on.) This code has now been added to pcre_study(); it finds a lower bound
1249        to the length of subject needed. It is not necessarily the greatest lower
1250        bound, but using it to avoid searching strings that are too short does give
1251        some useful speed-ups. The value is available to calling programs via
1252        pcre_fullinfo().
1254    26. While implementing 25, I discovered to my embarrassment that pcretest had
1255        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1256        study optimizations had never been tested with that matching function.
1257        Oops. What is worse, even when it was passed study data, there was a bug in
1258        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1259        were also very few tests of studied patterns with pcre_dfa_exec().
1261    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1262        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1263        on the other side of the coin, they are no longer allowed to have different
1264        names, because these cannot be distinguished in PCRE, and this has caused
1265        confusion. (This is a difference from Perl.)
1267    28. When duplicate subpattern names are present (necessarily with different
1268        numbers, as required by 27 above), and a test is made by name in a
1269        conditional pattern, either for a subpattern having been matched, or for
1270        recursion in such a pattern, all the associated numbered subpatterns are
1271        tested, and the overall condition is true if the condition is true for any
1272        one of them. This is the way Perl works, and is also more like the way
1273        testing by number works.
1276    Version 7.9 11-Apr-09
1277    ---------------------
1279    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1280        (pcretest), all targets were linked against these libraries. This included
1281        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1282        libraries. This caused unwanted dependencies to be created. This problem
1283        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1284        pcretest is linked with readline.
1286    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1287        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1288        moved outside it again, because FALSE and TRUE are already defined in AIX,
1289        but BOOL is not.
1291    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1292        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1294    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1295        hyphens) following file names and line numbers when outputting matching
1296        lines. This is not true; no spaces are inserted. I have also clarified the
1297        wording for the --colour (or --color) option.
1299    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1300        was not coloured; this is different to GNU grep, so I have changed it to be
1301        the same.
1303    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1304        each matching line was coloured. Now it goes on to look for further matches
1305        of any of the test patterns, which is the same behaviour as GNU grep.
1307    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1308        doesn't make sense to accept an empty string match in pcregrep, so I have
1309        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1310        seems to be how GNU grep behaves.
1312    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1313        start or after a newline", because the conditional assertion was not being
1314        correctly handled. The rule now is that both the assertion and what follows
1315        in the first alternative must satisfy the test.
1317    9.  If auto-callout was enabled in a pattern with a conditional group whose
1318        condition was an assertion, PCRE could crash during matching, both with
1319        pcre_exec() and pcre_dfa_exec().
1321    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1322        used for matching.
1324    11. Unicode property support in character classes was not working for
1325        characters (bytes) greater than 127 when not in UTF-8 mode.
1327    12. Added the -M command line option to pcretest.
1329    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1331    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1333    16. Added comments and documentation about mis-use of no_arg in the C++
1334        wrapper.
1336    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1337        from Martin Jerabek that uses macro names for all relevant character and
1338        string constants.
1340    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1341        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1342        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1343        these, but not everybody uses configure.
1345    19. A conditional group that had only one branch was not being correctly
1346        recognized as an item that could match an empty string. This meant that an
1347        enclosing group might also not be so recognized, causing infinite looping
1348        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1349        with the subject "ab", where knowledge that the repeated group can match
1350        nothing is needed in order to break the loop.
1352    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1353        exec(), but without supplying a callout function, matching went wrong.
1355    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1356        leak if the size of the offset vector was greater than 30. When the vector
1357        is smaller, the saved offsets during recursion go onto a local stack
1358        vector, but for larger vectors malloc() is used. It was failing to free
1359        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1360        error, in fact).
1362    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1363        heapframe that is used only when UTF-8 support is enabled. This caused no
1364        problem, but was untidy.
1366    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1367        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1368        included within another project.
1370    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1371        slightly modified by me:
1373          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1374              not building pcregrep.
1376          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1377              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1379    25. Forward references, both numeric and by name, in patterns that made use of
1380        duplicate group numbers, could behave incorrectly or give incorrect errors,
1381        because when scanning forward to find the reference group, PCRE was not
1382        taking into account the duplicate group numbers. A pattern such as
1383        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1385    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1386        the feature of a custom pointer more persuasive (as requested by a user).
1388    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1389        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1390        pre-defined.
1392    28. Added support for (*UTF8) at the start of a pattern.
1394    29. Arrange for flags added by the "release type" setting in CMake to be shown
1395        in the configuration summary.
1398    Version 7.8 05-Sep-08
1399    ---------------------
1401    1.  Replaced UCP searching code with optimized version as implemented for Ad
1402        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1403        stage table and inline lookup instead of a function, giving speed ups of 2
1404        to 5 times on some simple patterns that I tested. Permission was given to
1405        distribute the MultiStage2.py script that generates the tables (it's not in
1406        the tarball, but is in the Subversion repository).
1408    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1409        scripts.
1411    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1412        a group with a zero qualifier. The result of the study could be incorrect,
1413        or the function might crash, depending on the pattern.
1415    4.  Caseless matching was not working for non-ASCII characters in back
1416        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1417        It now works when Unicode Property Support is available.
1419    5.  In pcretest, an escape such as \x{de} in the data was always generating
1420        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1421        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1422        truncation.
1424    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1426    7.  Added two (int) casts to pcregrep when printing the difference of two
1427        pointers, in case they are 64-bit values.
1429    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1430        test 2 if it fails.
1432    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1433        and a #define of that name to empty if it is not externally set. This is to
1434        allow users of MSVC to set it if necessary.
1436    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1437        the convenience functions in the pcre_get.c source file.
1439    11. An option change at the start of a pattern that had top-level alternatives
1440        could cause overwriting and/or a crash. This command provoked a crash in
1441        some environments:
1443          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1445        This potential security problem was recorded as CVE-2008-2371.
1447    12. For a pattern where the match had to start at the beginning or immediately
1448        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1449        pcre_dfa_exec() could read past the end of the passed subject if there was
1450        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1451        pcretest so that it places the subject at the end of its malloc-ed buffer.
1453    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1454        exec() might read past the end of the data buffer in UTF-8 mode.
1456    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1457        the data contained the byte 0x85 as part of a UTF-8 character within its
1458        first line. This applied both to normal and DFA matching.
1460    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1461        /^[^d]*?$/8 failed to match "abc".
1463    16. Added a missing copyright notice to pcrecpp_internal.h.
1465    17. Make it more clear in the documentation that values returned from
1466        pcre_exec() in ovector are byte offsets, not character counts.
1468    18. Tidied a few places to stop certain compilers from issuing warnings.
1470    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1471        supplied by Stefan Weber. I made a further small update for 7.8 because
1472        there is a change of source arrangements: the pcre_searchfuncs.c module is
1473        replaced by pcre_ucd.c.
1476    Version 7.7 07-May-08
1477    ---------------------
1479    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1480        a string to a long long, pretend we don't even have a long long." This is
1481        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1483    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1484        pre-7.6 versions, which defined a global no_arg variable instead of putting
1485        it in the RE class. (See also #8 below.)
1487    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1488        Lopes.
1490    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1492        (1) The include/exclude patterns were being applied to the whole pathnames
1493            of files, instead of just to the final components.
1495        (2) If there was more than one level of directory, the subdirectories were
1496            skipped unless they satisfied the include/exclude conditions. This is
1497            inconsistent with GNU grep (and could even be seen as contrary to the
1498            pcregrep specification - which I improved to make it absolutely clear).
1499            The action now is always to scan all levels of directory, and just
1500            apply the include/exclude patterns to regular files.
1502    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1503        --exclude_dir in the tests to avoid scanning .svn directories.
1505    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1506        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1507        doesn't support NULs in patterns.
1509    7.  Added some missing "const"s to declarations of static tables in
1510        pcre_compile.c and pcre_dfa_exec.c.
1512    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1513        caused by fix #2  above. (Subsequently also a second patch to fix the
1514        first patch. And a third patch - this was a messy problem.)
1516    9.  Applied Craig's patch to remove the use of push_back().
1518    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1519        matching function regexec().
1521    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1522        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1523        references. PCRE supports relative numbers with this syntax (I don't think
1524        Oniguruma does).
1526    12. Previously, a group with a zero repeat such as (...){0} was completely
1527        omitted from the compiled regex. However, this means that if the group
1528        was called as a subroutine from elsewhere in the pattern, things went wrong
1529        (an internal error was given). Such groups are now left in the compiled
1530        pattern, with a new opcode that causes them to be skipped at execution
1531        time.
1533    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1534        to the way PCRE behaves:
1536        (a) A lone ] character is dis-allowed (Perl treats it as data).
1538        (b) A back reference to an unmatched subpattern matches an empty string
1539            (Perl fails the current match path).
1541        (c) A data ] in a character class must be notated as \] because if the
1542            first data character in a class is ], it defines an empty class. (In
1543            Perl it is not possible to have an empty class.) The empty class []
1544            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1545            The negative empty class [^] matches any one character, independently
1546            of the DOTALL setting.
1548    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1549        non-existent subpattern following a character class starting with ']' and
1550        containing () gave an internal compiling error instead of "reference to
1551        non-existent subpattern". Fortunately, when the pattern did exist, the
1552        compiled code was correct. (When scanning forwards to check for the
1553        existencd of the subpattern, it was treating the data ']' as terminating
1554        the class, so got the count wrong. When actually compiling, the reference
1555        was subsequently set up correctly.)
1557    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1558        it was being rejected as not supported by pcre_dfa_exec(), even though
1559        other assertions are supported. I have made pcre_dfa_exec() support
1560        (*FAIL).
1562    16. The implementation of 13c above involved the invention of a new opcode,
1563        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1564        cannot be changed at match time, I realized I could make a small
1565        improvement to matching performance by compiling OP_ALLANY instead of
1566        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1567        on the OP_ANY path.
1569    17. Compiling pcretest on Windows with readline support failed without the
1570        following two fixes: (1) Make the unistd.h include conditional on
1571        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1573    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1574        ncurses library to be included for pcretest when ReadLine support is
1575        requested, but also to allow for it to be overridden. This patch came from
1576        Daniel Bergström.
1578    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1579        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1580        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1581        spotting this.
1584    Version 7.6 28-Jan-08
1585    ---------------------
1587    1.  A character class containing a very large number of characters with
1588        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1589        overflow.
1591    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1592        HAVE_LONG_LONG is not defined.
1594    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1595        bring them up to date and include new features. This patch includes:
1597        - Fixed PH's badly added libz and libbz2 support.
1598        - Fixed a problem with static linking.
1599        - Added pcredemo. [But later removed - see 7 below.]
1600        - Fixed dftables problem and added an option.
1601        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1602            HAVE_LONG_LONG.
1603        - Added readline support for pcretest.
1604        - Added an listing of the option settings after cmake has run.
1606    4.  A user submitted a patch to Makefile that makes it easy to create
1607        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1608        Makefile.am that cause it to include this special target, without
1609        affecting anything else. Note that the same mingw target plus all
1610        the other distribution libraries and programs are now supported
1611        when configuring with CMake (see 6 below) instead of with
1612        Configure/Make.
1614    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1615        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1616        exported in the Windows port". It has not yet been confirmed that the patch
1617        solves the problem, but it does no harm.
1619    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1620        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1621        with CMake, and also correct the comment about stack recursion.
1623    7.  Remove the automatic building of pcredemo from the ./configure system and
1624        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1625        of a program that users should build themselves after PCRE is installed, so
1626        building it automatically is not really right. What is more, it gave
1627        trouble in some build environments.
1629    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1632    Version 7.5 10-Jan-08
1633    ---------------------
1635    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1636        values in parens when parsing an RE using the C++ wrapper."
1638    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1639        Characters greater than 255 were excluded from the class instead of being
1640        included.
1642    3.  The same bug as (2) above applied to negated POSIX classes such as
1643        [:^space:].
1645    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1646        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1647        I have changed it.
1649    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1650        first named subpattern) and a construct such as (?&a) would reference the
1651        first named subpattern whose name started with "a" (in other words, the
1652        length check was missing). Both these problems are fixed. "Subpattern name
1653        expected" is now given for (?&) (a zero-length name), and this patch also
1654        makes it give the same error for \k'' (previously it complained that that
1655        was a reference to a non-existent subpattern).
1657    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1658        this is right because (?- can be followed by option settings as well as by
1659        digits. I have, however, made the messages clearer.
1661    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1662        than the number used in the conditional) now cause a compile-time error.
1663        This is actually not compatible with Perl, which accepts such patterns, but
1664        treats the conditional as always being FALSE (as PCRE used to), but it
1665        seems to me that giving a diagnostic is better.
1667    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1668        and messages.
1670    9.  Fix two occurrences of "backslash" in comments that should have been
1671        "backspace".
1673    10. Remove two redundant lines of code that can never be obeyed (their function
1674        was moved elsewhere).
1676    11. The program that makes PCRE's Unicode character property table had a bug
1677        which caused it to generate incorrect table entries for sequences of
1678        characters that have the same character type, but are in different scripts.
1679        It amalgamated them into a single range, with the script of the first of
1680        them. In other words, some characters were in the wrong script. There were
1681        thirteen such cases, affecting characters in the following ranges:
1683          U+002b0 - U+002c1
1684          U+0060c - U+0060d
1685          U+0061e - U+00612
1686          U+0064b - U+0065e
1687          U+0074d - U+0076d
1688          U+01800 - U+01805
1689          U+01d00 - U+01d77
1690          U+01d9b - U+01dbf
1691          U+0200b - U+0200f
1692          U+030fc - U+030fe
1693          U+03260 - U+0327f
1694          U+0fb46 - U+0fbb1
1695          U+10450 - U+1049d
1697    12. The -o option (show only the matching part of a line) for pcregrep was not
1698        compatible with GNU grep in that, if there was more than one match in a
1699        line, it showed only the first of them. It now behaves in the same way as
1700        GNU grep.
1702    13. If the -o and -v options were combined for pcregrep, it printed a blank
1703        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1704        does the same. The return code can be used to tell if there were any
1705        non-matching lines.
1707    14. Added --file-offsets and --line-offsets to pcregrep.
1709    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1710        infinitely looping recursion. The bug was that positive lookaheads were not
1711        being skipped when checking for a possible empty match (negative lookaheads
1712        and both kinds of lookbehind were skipped).
1714    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1715        inclusion of <windows.h> to before rather than after the definition of
1716        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1718    17. Specifying a possessive quantifier with a specific limit for a Unicode
1719        character property caused pcre_compile() to compile bad code, which led at
1720        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1721        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1722        caused the error; without that there was no problem.
1724    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1726    19. Added --enable-pcretest-libreadline.
1728    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1729        RE::GlobalReplace(). As a result, the number of replacements returned was
1730        double what it should be. I removed one of the increments, but Craig sent a
1731        later patch that removed the other one (the right fix) and added unit tests
1732        that check the return values (which was not done before).
1734    21. Several CMake things:
1736        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1737            the names libpcre and libpcreposix, not just pcre and pcreposix.
1739        (2) The above change means that pcretest and pcregrep are now correctly
1740            linked with the newly-built libraries, not previously installed ones.
1744    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1745        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1746        UTF-8 newline character). The key issue is that the pattern starts .*;
1747        this means that the match must be either at the beginning, or after a
1748        newline. The bug was in the code for advancing after a failed match and
1749        checking that the new position followed a newline. It was not taking
1750        account of UTF-8 characters correctly.
1752    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1753        character classes. PCRE was not treating the sequence [:...:] as a
1754        character class unless the ... were all letters. Perl, however, seems to
1755        allow any characters between [: and :], though of course it rejects as
1756        unknown any "names" that contain non-letters, because all the known class
1757        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1758        for example, whereas PCRE did not - it did not recognize a POSIX character
1759        class. This seemed a bit dangerous, so the code has been changed to be
1760        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1761        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1762        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1763        Perl does, and where it didn't before.
1765    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1766        Windows environments %n is disabled by default.
1769    Version 7.4 21-Sep-07
1770    ---------------------
1772    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1773        means that a class such as [\s] counted as "explicit reference to CR or
1774        LF". That isn't really right - the whole point of the change was to try to
1775        help when there was an actual mention of one of the two characters. So now
1776        the change happens only if \r or \n (or a literal CR or LF) character is
1777        encountered.
1779    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1780        of both had grown to the point where there were only 3 bits left.
1781        Fortunately, there was spare space in the data structure, and so I have
1782        moved the internal flags into a new 16-bit field to free up more option
1783        bits.
1785    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1786        but did not set the internal JCHANGED flag - either of these is enough to
1787        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1788        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1789        start sets both bits.
1791    4.  Added options (at build time, compile time, exec time) to change \R from
1792        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1794    5.  doc/pcresyntax.html was missing from the distribution.
1796    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1797        compatibility, even though it is no longer used.
1799    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1800        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1801        windows.h file is present (where different names are used). [This was
1802        reversed later after testing - see 16 below.]
1804    8.  Changed all #include <config.h> to #include "config.h". There were also
1805        some further <pcre.h> cases that I changed to "pcre.h".
1807    9.  When pcregrep was used with the --colour option, it missed the line ending
1808        sequence off the lines that it output.
1810    10. It was pointed out to me that arrays of string pointers cause lots of
1811        relocations when a shared library is dynamically loaded. A technique of
1812        using a single long string with a table of offsets can drastically reduce
1813        these. I have refactored PCRE in four places to do this. The result is
1814        dramatic:
1816          Originally:                          290
1817          After changing UCP table:            187
1818          After changing error message table:   43
1819          After changing table of "verbs"       36
1820          After changing table of Posix names   22
1822        Thanks to the folks working on Gregex for glib for this insight.
1824    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1825        unicode-properties was also set.
1827    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1829    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1830        checked only for CRLF.
1832    14. Added casts to pcretest.c to avoid compiler warnings.
1834    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1836    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1837        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1838        entirely. This removes changes made in 7 above.
1840    17. The CMake files have been updated, and there is now more information about
1841        building with CMake in the NON-UNIX-USE document.
1844    Version 7.3 28-Aug-07
1845  ---------------------  ---------------------
1847   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 29  Version 7.3 05-Jul-07 Line 1869  Version 7.3 05-Jul-07
1869   4. Debugging: adjusted the names of opcodes for different kinds of parentheses   4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1870      in debug output.      in debug output.
1872   5. Arrange to use "%I64d" instead of "%lld" for long printing in the pcrecpp   5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1873      unittest when running under MinGW.      long printing in the pcrecpp unittest when running under MinGW.
1875   6. ESC_K was left out of the EBCDIC table.   6. ESC_K was left out of the EBCDIC table.
# Line 48  Version 7.3 05-Jul-07 Line 1888  Version 7.3 05-Jul-07
1888      from the 1000-entry workspace that had been reserved. So now there is no      from the 1000-entry workspace that had been reserved. So now there is no
1889      explicit limit, but more stack is used.      explicit limit, but more stack is used.
1891     8. Applied Daniel's patches to solve problems with the import/export magic
1892        syntax that is required for Windows, and which was going wrong for the
1893        pcreposix and pcrecpp parts of the library. These were overlooked when this
1894        problem was solved for the main library.
1896     9. There were some crude static tests to avoid integer overflow when computing
1897        the size of patterns that contain repeated groups with explicit upper
1898        limits. As the maximum quantifier is 65535, the maximum group length was
1899        set at 30,000 so that the product of these two numbers did not overflow a
1900        32-bit integer. However, it turns out that people want to use groups that
1901        are longer than 30,000 bytes (though not repeat them that many times).
1902        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1903        made it possible to implement the integer overflow checks in a much more
1904        dynamic way, which I have now done. The artificial limitation on group
1905        length has been removed - we now have only the limit on the total length of
1906        the compiled pattern, which depends on the LINK_SIZE setting.
1908    10. Fixed a bug in the documentation for get/copy named substring when
1909        duplicate names are permitted. If none of the named substrings are set, the
1910        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1911        empty string.
1913    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1914        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1915        because the ] is interpreted as the first data character and the
1916        terminating ] is not found. PCRE has been made compatible with Perl in this
1917        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1918        cause memory overwriting.
1920    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1921        string has been matched (to stop an infinite loop). It was not recognizing
1922        a conditional subpattern that could match an empty string if that
1923        subpattern was within another subpattern. For example, it looped when
1924        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1925        condition was not nested. This bug has been fixed.
1927    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1928        past the start of the subject in the presence of bytes with the top bit
1929        set, for example "\x8aBCD".
1931    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1932        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1934    14. Optimized (?!) to (*FAIL).
1936    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1937        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1938        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1939        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1940        does: it's just the validity check that is more restrictive.
1942    16. Inserted checks for integer overflows during escape sequence (backslash)
1943        processing, and also fixed erroneous offset values for syntax errors during
1944        backslash processing.
1946    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1947        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1949    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1950        caused an overrun.
1952    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1953        something other than just ASCII characters) inside a group that had an
1954        unlimited repeat caused a loop at compile time (while checking to see
1955        whether the group could match an empty string).
1957    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1958        [\P{Any}] did so. (Error in the code for printing property names.)
1960    21. An orphan \E inside a character class could cause a crash.
1962    22. A repeated capturing bracket such as (A)? could cause a wild memory
1963        reference during compilation.
1965    23. There are several functions in pcre_compile() that scan along a compiled
1966        expression for various reasons (e.g. to see if it's fixed length for look
1967        behind). There were bugs in these functions when a repeated \p or \P was
1968        present in the pattern. These operators have additional parameters compared
1969        with \d, etc, and these were not being taken into account when moving along
1970        the compiled data. Specifically:
1972        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1973            length.
1975        (b) An item such as \pL+ within a repeated group could cause crashes or
1976            loops.
1978        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1979            "reference to non-existent subpattern" error.
1981        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1983    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1984        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1986    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1988    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1989        character were causing crashes (broken optimization).
1991    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1992        \p or \P) caused a compile-time loop.
1994    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1995        break. For example, the unstudied pattern [\r\n]A does not match the string
1996        "\r\nA" because change 7.0/46 below moves the current point on by two
1997        characters after failing to match at the start. However, the pattern \nA
1998        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1999        the same is true. There doesn't seem any very clean way out of this, but
2000        what I have chosen to do makes the common cases work: PCRE now takes note
2001        of whether there can be an explicit match for \r or \n anywhere in the
2002        pattern, and if so, 7.0/46 no longer applies. As part of this change,
2003        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2004        pattern has explicit CR or LF references.
2006    29. Added (*CR) etc for changing newline setting at start of pattern.
2009  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
2010  ---------------------  ---------------------

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