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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.0 02 Jul-08  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.
69    Version 8.30 04-February-2012
70    -----------------------------
72    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
73        name is defined in ctype.h.
75    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
76        only in quite long subpatterns.
78    3.  Removed the function pcre_info(), which has been obsolete and deprecated
79        since it was replaced by pcre_fullinfo() in February 2000.
81    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
82        match a (*MARK), and the match failed at the start of the subject, a
83        reference to memory before the start of the subject could occur. This bug
84        was introduced by fix 17 of release 8.21.
86    5.  A reference to an unset group with zero minimum repetition was giving
87        totally wrong answers (in non-JavaScript-compatibility mode). For example,
88        /(another)?(\1?)test/ matched against "hello world test". This bug was
89        introduced in release 8.13.
91    6.  Add support for 16-bit character strings (a large amount of work involving
92        many changes and refactorings).
94    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
95        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
96        from a file.
98    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
99        rounding is not applied in this particular case).
101    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
102        if they appear, or are escaped, in patterns.
104    10. Get rid of a number of -Wunused-but-set-variable warnings.
106    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
107        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
108        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
109        also returns the mark "x". This bug applied to capturing parentheses,
110        non-capturing parentheses, and atomic parentheses. It also applied to some
111        assertions.
113    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
114        information out of configure.ac instead of relying on pcre.h.generic, which
115        is not stored in the repository.
117    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
118        -lreadline.
120    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
122    15. Applied Graycode's patch to put the top-level frame on the stack rather
123        than the heap when not using the stack for recursion. This gives a
124        performance improvement in many cases when recursion is not deep.
126    16. Experimental code added to "pcretest -C" to output the stack frame size.
129    Version 8.21 12-Dec-2011
130    ------------------------
132    1.  Updating the JIT compiler.
134    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
135        are added as well.
137    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
138        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
139        calling _pcre_jit_exec. Some extra comments are added.
141    4.  (*MARK) settings inside atomic groups that do not contain any capturing
142        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
143        was introduced by change 18 for 8.20.
145    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
146        ECMA-262 standard.
148    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
149        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
150        This bug was probably introduced by change 9 of 8.13.
152    7.  While fixing 6 above, I noticed that a number of other items were being
153        incorrectly rejected as "not fixed length". This arose partly because newer
154        opcodes had not been added to the fixed-length checking code. I have (a)
155        corrected the bug and added tests for these items, and (b) arranged for an
156        error to occur if an unknown opcode is encountered while checking for fixed
157        length instead of just assuming "not fixed length". The items that were
158        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
159        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
160        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
162    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
163        being incorrectly compiled and would have given unpredicatble results.
165    9.  A possessively repeated subpattern with minimum repeat count greater than
166        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
167        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
168        the first (A) could occur when it should not.
170    10. Add a cast and remove a redundant test from the code.
172    11. JIT should use pcre_malloc/pcre_free for allocation.
174    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
175        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
176        is anything other than /usr, -L is still shown).
178    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
180    14. Perl does not support \N without a following name in a [] class; PCRE now
181        also gives an error.
183    15. If a forward reference was repeated with an upper limit of around 2000,
184        it caused the error "internal error: overran compiling workspace". The
185        maximum number of forward references (including repeats) was limited by the
186        internal workspace, and dependent on the LINK_SIZE. The code has been
187        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
188        the default depends on LINK_SIZE. There is a new upper limit (for safety)
189        of around 200,000 forward references. While doing this, I also speeded up
190        the filling in of repeated forward references.
192    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
193        incorrectly expecting the subject to contain another "a" after the start.
195    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
196        in the match, the SKIP should be ignored. This was not happening; instead
197        the SKIP was being treated as NOMATCH. For patterns such as
198        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
199        tested.
201    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
202        now much more compatible with Perl, in particular in cases where the result
203        is a non-match for a non-anchored pattern. For example, if
204        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
205        "m", where previously it did not return a name. A side effect of this
206        change is that for partial matches, the last encountered mark name is
207        returned, as for non matches. A number of tests that were previously not
208        Perl-compatible have been moved into the Perl-compatible test files. The
209        refactoring has had the pleasing side effect of removing one argument from
210        the match() function, thus reducing its stack requirements.
212    19. If the /S+ option was used in pcretest to study a pattern using JIT,
213        subsequent uses of /S (without +) incorrectly behaved like /S+.
215    21. Retrieve executable code size support for the JIT compiler and fixing
216        some warnings.
218    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
219        not work when the shorter character appeared right at the end of the
220        subject string.
222    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
223        systems.
225    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
226        output it when the /M option is used in pcretest.
228    25. The CheckMan script was not being included in the distribution. Also, added
229        an explicit "perl" to run Perl scripts from the PrepareRelease script
230        because this is reportedly needed in Windows.
232    26. If study data was being save in a file and studying had not found a set of
233        "starts with" bytes for the pattern, the data written to the file (though
234        never used) was taken from uninitialized memory and so caused valgrind to
235        complain.
237    27. Updated RunTest.bat as provided by Sheri Pierce.
239    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
241    29. Computation of memory usage for the table of capturing group names was
242        giving an unnecessarily large value.
245    Version 8.20 21-Oct-2011
246    ------------------------
248    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
249        a POSIX class. After further experiments with Perl, which convinced me that
250        Perl has bugs and confusions, a closing square bracket is no longer allowed
251        in a POSIX name. This bug also affected patterns with classes that started
252        with full stops.
254    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
255        captured substring, but while checking the failing first alternative,
256        substring 1 is temporarily captured. If the output vector supplied to
257        pcre_exec() was not big enough for this capture, the yield of the function
258        was still zero ("insufficient space for captured substrings"). This cannot
259        be totally fixed without adding another stack variable, which seems a lot
260        of expense for a edge case. However, I have improved the situation in cases
261        such as /(a)(b)x|abc/ matched against "abc", where the return code
262        indicates that fewer than the maximum number of slots in the ovector have
263        been set.
265    3.  Related to (2) above: when there are more back references in a pattern than
266        slots in the output vector, pcre_exec() uses temporary memory during
267        matching, and copies in the captures as far as possible afterwards. It was
268        using the entire output vector, but this conflicts with the specification
269        that only 2/3 is used for passing back captured substrings. Now it uses
270        only the first 2/3, for compatibility. This is, of course, another edge
271        case.
273    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
274        main code base, and can be used by building with --enable-jit. When this is
275        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
276        runtime --no-jit option is given.
278    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
279        ovector, the return from the function was zero, implying that there were
280        other matches that did not fit. The correct "exactly full" value is now
281        returned.
283    6.  If a subpattern that was called recursively or as a subroutine contained
284        (*PRUNE) or any other control that caused it to give a non-standard return,
285        invalid errors such as "Error -26 (nested recursion at the same subject
286        position)" or even infinite loops could occur.
288    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
289        computing the minimum length on reaching *ACCEPT, and so ended up with the
290        wrong value of 1 rather than 0. Further investigation indicates that
291        computing a minimum subject length in the presence of *ACCEPT is difficult
292        (think back references, subroutine calls), and so I have changed the code
293        so that no minimum is registered for a pattern that contains *ACCEPT.
295    8.  If (*THEN) was present in the first (true) branch of a conditional group,
296        it was not handled as intended. [But see 16 below.]
298    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
299        Sheri Pierce.
301    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
302        the first byte in a match must be "a".
304    11. Change 17 for 8.13 increased the recursion depth for patterns like
305        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
306        pattern contains any instances of (*THEN). If it does not, the old
307        optimizations are restored. It would be nice to do this on a per-group
308        basis, but at the moment that is not feasible.
310    12. In some environments, the output of pcretest -C is CRLF terminated. This
311        broke RunTest's code that checks for the link size. A single white space
312        character after the value is now allowed for.
314    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
315        For "fr", it uses the Windows-specific input and output files.
317    14. If (*THEN) appeared in a group that was called recursively or as a
318        subroutine, it did not work as intended. [But see next item.]
320    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
321        pattern fragments (but not containing any | characters). If A and B are
322        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
323        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
324        D. In other words, Perl considers parentheses that do not contain any |
325        characters to be part of a surrounding alternative, whereas PCRE was
326        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
327        differently. PCRE now behaves in the same way as Perl, except in the case
328        of subroutine/recursion calls such as (?1) which have in any case always
329        been different (but PCRE had them first :-).
331    16. Related to 15 above: Perl does not treat the | in a conditional group as
332        creating alternatives. Such a group is treated in the same way as an
333        ordinary group without any | characters when processing (*THEN). PCRE has
334        been changed to match Perl's behaviour.
336    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
337        RunGrepTest script failed.
339    18. Change 22 for version 13 caused atomic groups to use more stack. This is
340        inevitable for groups that contain captures, but it can lead to a lot of
341        stack use in large patterns. The old behaviour has been restored for atomic
342        groups that do not contain any capturing parentheses.
344    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
345        suppress the check for a minimum subject length at run time. (If it was
346        given to pcre_exec() or pcre_dfa_exec() it did work.)
348    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
349        fail to work when decoding hex characters in data strings in EBCDIC
350        environments.
352    21. It appears that in at least one Mac OS environment, the isxdigit() function
353        is implemented as a macro that evaluates to its argument more than once,
354        contravening the C 90 Standard (I haven't checked a later standard). There
355        was an instance in pcretest which caused it to go wrong when processing
356        \x{...} escapes in subject strings. The has been rewritten to avoid using
357        things like p++ in the argument of isxdigit().
360    Version 8.13 16-Aug-2011
361    ------------------------
363    1.  The Unicode data tables have been updated to Unicode 6.0.0.
365    2.  Two minor typos in pcre_internal.h have been fixed.
367    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
368        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
369        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
371    4.  There were a number of related bugs in the code for matching backrefences
372        caselessly in UTF-8 mode when codes for the characters concerned were
373        different numbers of bytes. For example, U+023A and U+2C65 are an upper
374        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
375        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
376        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
377        2-byte code at the end of the subject (it thought there wasn't enough data
378        left).
380    5.  Comprehensive information about what went wrong is now returned by
381        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
382        as the output vector has at least 2 elements. The offset of the start of
383        the failing character and a reason code are placed in the vector.
385    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
386        now returned is for the first byte of the failing character, instead of the
387        last byte inspected. This is an incompatible change, but I hope it is small
388        enough not to be a problem. It makes the returned offset consistent with
389        pcre_exec() and pcre_dfa_exec().
391    7.  pcretest now gives a text phrase as well as the error number when
392        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
393        failure, the offset and reason code are output.
395    8.  When \R was used with a maximizing quantifier it failed to skip backwards
396        over a \r\n pair if the subsequent match failed. Instead, it just skipped
397        back over a single character (\n). This seems wrong (because it treated the
398        two characters as a single entity when going forwards), conflicts with the
399        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
400        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
401        has been changed.
403    9.  Some internal refactoring has changed the processing so that the handling
404        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
405        time (the PCRE_DOTALL option was changed this way some time ago: version
406        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
407        which was always a bit of a fudge. It also means that there is one less
408        argument for the match() function, which reduces its stack requirements
409        slightly. This change also fixes an incompatibility with Perl: the pattern
410        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
412    10. More internal refactoring has drastically reduced the number of recursive
413        calls to match() for possessively repeated groups such as (abc)++ when
414        using pcre_exec().
416    11. While implementing 10, a number of bugs in the handling of groups were
417        discovered and fixed:
419        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
420        (a|)*(?1) gave a compile-time internal error.
421        ((a|)+)+  did not notice that the outer group could match an empty string.
422        (^a|^)+   was not marked as anchored.
423        (.*a|.*)+ was not marked as matching at start or after a newline.
425    12. Yet more internal refactoring has removed another argument from the match()
426        function. Special calls to this function are now indicated by setting a
427        value in a variable in the "match data" data block.
429    13. Be more explicit in pcre_study() instead of relying on "default" for
430        opcodes that mean there is no starting character; this means that when new
431        ones are added and accidentally left out of pcre_study(), testing should
432        pick them up.
434    14. The -s option of pcretest has been documented for ages as being an old
435        synonym of -m (show memory usage). I have changed it to mean "force study
436        for every regex", that is, assume /S for every regex. This is similar to -i
437        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
438        using it. It makes it easier to run collections of tests with and without
439        study enabled, and thereby test pcre_study() more easily. All the standard
440        tests are now run with and without -s (but some patterns can be marked as
441        "never study" - see 20 below).
443    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
444        restoration of the capturing data to the outer values was not happening
445        correctly.
447    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
448        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
449        pattern had matched an empty string, and so incorrectly returned a no
450        match.
452    17. There was optimizing code for the last branch of non-capturing parentheses,
453        and also for the obeyed branch of a conditional subexpression, which used
454        tail recursion to cut down on stack usage. Unfortunately, now that there is
455        the possibility of (*THEN) occurring in these branches, tail recursion is
456        no longer possible because the return has to be checked for (*THEN). These
457        two optimizations have therefore been removed. [But see 8.20/11 above.]
459    18. If a pattern containing \R was studied, it was assumed that \R always
460        matched two bytes, thus causing the minimum subject length to be
461        incorrectly computed because \R can also match just one byte.
463    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
464        was incorrectly computed.
466    20. If /S is present twice on a test pattern in pcretest input, it now
467        *disables* studying, thereby overriding the use of -s on the command line
468        (see 14 above). This is necessary for one or two tests to keep the output
469        identical in both cases.
471    21. When (*ACCEPT) was used in an assertion that matched an empty string and
472        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
474    22. When an atomic group that contained a capturing parenthesis was
475        successfully matched, but the branch in which it appeared failed, the
476        capturing was not being forgotten if a higher numbered group was later
477        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
478        group 1 to "a", when in fact it should be unset. This applied to multi-
479        branched capturing and non-capturing groups, repeated or not, and also to
480        positive assertions (capturing in negative assertions does not happen
481        in PCRE) and also to nested atomic groups.
483    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
484        subject after a captured substring, to make it easier to tell which of a
485        number of identical substrings has been captured.
487    24. The way atomic groups are processed by pcre_exec() has been changed so that
488        if they are repeated, backtracking one repetition now resets captured
489        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
490        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
491        "aaa". Previously, it would have been "a". As part of this code
492        refactoring, the way recursive calls are handled has also been changed.
494    25. If an assertion condition captured any substrings, they were not passed
495        back unless some other capturing happened later. For example, if
496        (?(?=(a))a) was matched against "a", no capturing was returned.
498    26. When studying a pattern that contained subroutine calls or assertions,
499        the code for finding the minimum length of a possible match was handling
500        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
501        group 1 called group 2 while simultaneously a separate group 2 called group
502        1). A stack overflow occurred in this case. I have fixed this by limiting
503        the recursion depth to 10.
505    27. Updated RunTest.bat in the distribution to the version supplied by Tom
506        Fortmann. This supports explicit test numbers on the command line, and has
507        argument validation and error reporting.
509    28. An instance of \X with an unlimited repeat could fail if at any point the
510        first character it looked at was a mark character.
512    29. Some minor code refactoring concerning Unicode properties and scripts
513        should reduce the stack requirement of match() slightly.
515    30. Added the '=' option to pcretest to check the setting of unused capturing
516        slots at the end of the pattern, which are documented as being -1, but are
517        not included in the return count.
519    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
520        compiled something random. Now it gives a compile-time error (as does
521        Perl).
523    32. A *MARK encountered during the processing of a positive assertion is now
524        recorded and passed back (compatible with Perl).
526    33. If --only-matching or --colour was set on a pcregrep call whose pattern
527        had alternative anchored branches, the search for a second match in a line
528        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
529        matched the line "0102" twice. The same bug affected patterns that started
530        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
531        twice.
533    34. Previously, PCRE did not allow quantification of assertions. However, Perl
534        does, and because of capturing effects, quantifying parenthesized
535        assertions may at times be useful. Quantifiers are now allowed for
536        parenthesized assertions.
538    35. A minor code tidy in pcre_compile() when checking options for \R usage.
540    36. \g was being checked for fancy things in a character class, when it should
541        just be a literal "g".
543    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
544        appearance of a nested POSIX class supersedes an apparent external class.
545        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
546        unescaped square brackets may also appear as part of class names. For
547        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
548        more like Perl. (But see 8.20/1 above.)
550    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
551        was because it thought it was \N{name}, which is not supported).
553    39. Add minix to OS list not supporting the -S option in pcretest.
555    40. PCRE tries to detect cases of infinite recursion at compile time, but it
556        cannot analyze patterns in sufficient detail to catch mutual recursions
557        such as ((?1))((?2)). There is now a runtime test that gives an error if a
558        subgroup is called recursively as a subpattern for a second time at the
559        same position in the subject string. In previous releases this might have
560        been caught by the recursion limit, or it might have run out of stack.
562    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
563        happen only once. PCRE was, however incorrectly giving a compile time error
564        "recursive call could loop indefinitely" because it cannot analyze the
565        pattern in sufficient detail. The compile time test no longer happens when
566        PCRE is compiling a conditional subpattern, but actual runaway loops are
567        now caught at runtime (see 40 above).
569    42. It seems that Perl allows any characters other than a closing parenthesis
570        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
571        has been changed to be the same.
573    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
574        as not to get warnings when autogen.sh is called. Also changed
575        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
577    44. To help people who use pcregrep to scan files containing exceedingly long
578        lines, the following changes have been made:
580        (a) The default value of the buffer size parameter has been increased from
581            8K to 20K. (The actual buffer used is three times this size.)
583        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
584            PCRE is built.
586        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
587            to be set at run time.
589        (d) Numerical values in pcregrep options can be followed by K or M, for
590            example --buffer-size=50K.
592        (e) If a line being scanned overflows pcregrep's buffer, an error is now
593            given and the return code is set to 2.
595    45. Add a pointer to the latest mark to the callout data block.
597    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
598        partial match of an empty string instead of no match. This was specific to
599        the use of ".".
601    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
602        complete match instead of a partial match. This bug was dependent on both
603        the PCRE_UTF8 and PCRE_DOTALL options being set.
605    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
606        starting byte set, because \b was not being ignored.
609    Version 8.12 15-Jan-2011
610    ------------------------
612    1.  Fixed some typos in the markup of the man pages, and wrote a script that
613        checks for such things as part of the documentation building process.
615    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
616        --match-limit and --recursion-limit options (added for 8.11). In
617        particular, this made one of the standard tests fail. (The integer value
618        went into the wrong half of a long int.)
620    3.  If the --colour option was given to pcregrep with -v (invert match), it
621        did strange things, either producing crazy output, or crashing. It should,
622        of course, ignore a request for colour when reporting lines that do not
623        match.
625    4.  Another pcregrep bug caused similar problems if --colour was specified with
626        -M (multiline) and the pattern match finished with a line ending.
628    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
629        matched in multiline mode, the following line was shown as part of the
630        match. This seems wrong, so I have changed it.
632    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
633        the check for further matches in the same line (so they could be coloured)
634        to overrun the end of the current line. If another match was found, it was
635        incorrectly shown (and then shown again when found in the next line).
637    7.  If pcregrep was compiled under Windows, there was a reference to the
638        function pcregrep_exit() before it was defined. I am assuming this was
639        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
640        reported by a user. I've moved the definition above the reference.
643    Version 8.11 10-Dec-2010
644    ------------------------
646    1.  (*THEN) was not working properly if there were untried alternatives prior
647        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
648        backtracked to try for "b" instead of moving to the next alternative branch
649        at the same level (in this case, to look for "c"). The Perl documentation
650        is clear that when (*THEN) is backtracked onto, it goes to the "next
651        alternative in the innermost enclosing group".
653    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
654        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
655        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
656        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
657        (*THEN).
659    3.  If \s appeared in a character class, it removed the VT character from
660        the class, even if it had been included by some previous item, for example
661        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
662        of \s, but is part of the POSIX "space" class.)
664    4.  A partial match never returns an empty string (because you can always
665        match an empty string at the end of the subject); however the checking for
666        an empty string was starting at the "start of match" point. This has been
667        changed to the "earliest inspected character" point, because the returned
668        data for a partial match starts at this character. This means that, for
669        example, /(?<=abc)def/ gives a partial match for the subject "abc"
670        (previously it gave "no match").
672    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
673        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
674        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
675        has an implication that the given string is incomplete (because a partial
676        match is preferred over a full match). For this reason, these items now
677        give a partial match in this situation. [Aside: previously, the one case
678        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
679        match rather than a full match, which was wrong by the old rules, but is
680        now correct.]
682    6.  There was a bug in the handling of #-introduced comments, recognized when
683        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
684        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
685        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
686        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
687        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
688        places in pcre_compile().
690    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
691        comments when looking ahead for named forward references to subpatterns,
692        the only newline sequence it recognized was NL. It now handles newlines
693        according to the set newline convention.
695    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
696        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
697        cater for a lack of strerror(). These oversights have been fixed.
699    9.  Added --match-limit and --recursion-limit to pcregrep.
701    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
703    11. When the -o option was used, pcregrep was setting a return code of 1, even
704        when matches were found, and --line-buffered was not being honoured.
706    12. Added an optional parentheses number to the -o and --only-matching options
707        of pcregrep.
709    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
710        can match an empty string. The code to do it in pcretest and pcredemo
711        needed fixing:
713        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
714            only one byte after an empty string match just before CRLF (this case
715            just got forgotten; "any" and "anycrlf" were OK).
717        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
718            mode when an empty string match preceded an ASCII character followed by
719            a non-ASCII character. (The code for advancing by one character rather
720            than one byte was nonsense.)
722        (c) The pcredemo.c sample program did not have any code at all to handle
723            the cases when CRLF is a valid newline sequence.
725    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
726        as a starting offset was within the subject string. There is now a new
727        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
728        negative or greater than the length of the string. In order to test this,
729        pcretest is extended to allow the setting of negative starting offsets.
731    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
732        starting offset points to the beginning of a UTF-8 character was
733        unnecessarily clumsy. I tidied it up.
735    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
736        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
738    17. Nobody had reported that the --include_dir option, which was added in
739        release 7.7 should have been called --include-dir (hyphen, not underscore)
740        for compatibility with GNU grep. I have changed it to --include-dir, but
741        left --include_dir as an undocumented synonym, and the same for
742        --exclude-dir, though that is not available in GNU grep, at least as of
743        release 2.5.4.
745    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
746        characters from a string of bytes) have been redefined so as not to use
747        loops, in order to improve performance in some environments. At the same
748        time, I abstracted some of the common code into auxiliary macros to save
749        repetition (this should not affect the compiled code).
751    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
752        compile-time error is now given if \c is not followed by an ASCII
753        character, that is, a byte less than 128. (In EBCDIC mode, the code is
754        different, and any byte value is allowed.)
756    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
757        START_OPTIMIZE option, which is now allowed at compile time - but just
758        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
759        to pcregrep and other applications that have no direct access to PCRE
760        options. The new /Y option in pcretest sets this option when calling
761        pcre_compile().
763    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
764        back references. Groups containing recursive back references were forced to
765        be atomic by that change, but in the case of named groups, the amount of
766        memory required was incorrectly computed, leading to "Failed: internal
767        error: code overflow". This has been fixed.
769    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
770        pcretest.c, to avoid build problems in some Borland environments.
773    Version 8.10 25-Jun-2010
774    ------------------------
776    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
777        THEN.
779    2.  (*ACCEPT) was not working when inside an atomic group.
781    3.  Inside a character class, \B is treated as a literal by default, but
782        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
783        causes the error). The code is unchanged, but I tidied the documentation.
785    4.  Inside a character class, PCRE always treated \R and \X as literals,
786        whereas Perl faults them if its -w option is set. I have changed PCRE so
787        that it faults them when PCRE_EXTRA is set.
789    5.  Added support for \N, which always matches any character other than
790        newline. (It is the same as "." when PCRE_DOTALL is not set.)
792    6.  When compiling pcregrep with newer versions of gcc which may have
793        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
794        declared with attribute warn_unused_result" were given. Just casting the
795        result to (void) does not stop the warnings; a more elaborate fudge is
796        needed. I've used a macro to implement this.
798    7.  Minor change to pcretest.c to avoid a compiler warning.
800    8.  Added four artifical Unicode properties to help with an option to make
801        \s etc use properties (see next item). The new properties are: Xan
802        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
804    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
805        use Unicode properties. (*UCP) at the start of a pattern can be used to set
806        this option. Modified pcretest to add /W to test this facility. Added
807        REG_UCP to make it available via the POSIX interface.
809    10. Added --line-buffered to pcregrep.
811    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
812        studied, and the match started with a letter with a code point greater than
813        127 whose first byte was different to the first byte of the other case of
814        the letter, the other case of this starting letter was not recognized
815        (#976).
817    12. If a pattern that was studied started with a repeated Unicode property
818        test, for example, \p{Nd}+, there was the theoretical possibility of
819        setting up an incorrect bitmap of starting bytes, but fortunately it could
820        not have actually happened in practice until change 8 above was made (it
821        added property types that matched character-matching opcodes).
823    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
824        possible starting bytes for non-anchored patterns.
826    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
827        \R, and also a number of cases that involve Unicode properties, both
828        explicit and implicit when PCRE_UCP is set.
830    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
831        input, it could crash or give wrong results if characters with values
832        greater than 0xc0 were present in the subject string. (Detail: it assumed
833        UTF-8 input when processing these items.)
835    16. Added a lot of (int) casts to avoid compiler warnings in systems where
836        size_t is 64-bit (#991).
838    17. Added a check for running out of memory when PCRE is compiled with
839        --disable-stack-for-recursion (#990).
841    18. If the last data line in a file for pcretest does not have a newline on
842        the end, a newline was missing in the output.
844    19. The default pcre_chartables.c file recognizes only ASCII characters (values
845        less than 128) in its various bitmaps. However, there is a facility for
846        generating tables according to the current locale when PCRE is compiled. It
847        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
848        characters, are recognized by isspace() and therefore were getting set in
849        these tables, and indeed these tables seem to approximate to ISO 8859. This
850        caused a problem in UTF-8 mode when pcre_study() was used to create a list
851        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
852        which of course cannot start UTF-8 characters. I have changed the code so
853        that only real ASCII characters (less than 128) and the correct starting
854        bytes for UTF-8 encodings are set for characters greater than 127 when in
855        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
856        altogether.)
858    20. Added the /T option to pcretest so as to be able to run tests with non-
859        standard character tables, thus making it possible to include the tests
860        used for 19 above in the standard set of tests.
862    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
863        reference to a subpattern the other side of a comment that contains an
864        opening parenthesis caused either an internal compiling error, or a
865        reference to the wrong subpattern.
868    Version 8.02 19-Mar-2010
869    ------------------------
871    1.  The Unicode data tables have been updated to Unicode 5.2.0.
873    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
874        configured.
876    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
877        original author of that file, following a query about its status.
879    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
880        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
882    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
883        quantifier applied to a forward-referencing subroutine call, could compile
884        incorrect code or give the error "internal error: previously-checked
885        referenced subpattern not found".
887    6.  Both MS Visual Studio and Symbian OS have problems with initializing
888        variables to point to external functions. For these systems, therefore,
889        pcre_malloc etc. are now initialized to local functions that call the
890        relevant global functions.
892    7.  There were two entries missing in the vectors called coptable and poptable
893        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
894        I've fixed the data, and added a kludgy way of testing at compile time that
895        the lengths are correct (equal to the number of opcodes).
897    8.  Following on from 7, I added a similar kludge to check the length of the
898        eint vector in pcreposix.c.
900    9.  Error texts for pcre_compile() are held as one long string to avoid too
901        much relocation at load time. To find a text, the string is searched,
902        counting zeros. There was no check for running off the end of the string,
903        which could happen if a new error number was added without updating the
904        string.
906    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
908    11. \K was not working if it appeared in an atomic group or in a group that
909        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
910        \K is "not well defined" if used in an assertion. PCRE now accepts it if
911        the assertion is positive, but not if it is negative.
913    12. Change 11 fortuitously reduced the size of the stack frame used in the
914        "match()" function of pcre_exec.c by one pointer. Forthcoming
915        implementation of support for (*MARK) will need an extra pointer on the
916        stack; I have reserved it now, so that the stack frame size does not
917        decrease.
919    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
920        item in branch that calls a recursion is a subroutine call - as in the
921        second branch in the above example - was incorrectly given the compile-
922        time error "recursive call could loop indefinitely" because pcre_compile()
923        was not correctly checking the subroutine for matching a non-empty string.
925    14. The checks for overrunning compiling workspace could trigger after an
926        overrun had occurred. This is a "should never occur" error, but it can be
927        triggered by pathological patterns such as hundreds of nested parentheses.
928        The checks now trigger 100 bytes before the end of the workspace.
930    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
933    Version 8.01 19-Jan-2010
934    ------------------------
936    1.  If a pattern contained a conditional subpattern with only one branch (in
937        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
938        computed the wrong minimum data length (which is of course zero for such
939        subpatterns). This could cause incorrect "no match" results.
941    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
942        the pattern is reset in the first branch, pcre_compile() failed with
943        "internal error: code overflow at offset...". This happened only when
944        the reset was to the original external option setting. (An optimization
945        abstracts leading options settings into an external setting, which was the
946        cause of this.)
948    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
949        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
950        assertion pattern did not match (meaning that the assertion was true), it
951        was incorrectly treated as false if the SKIP had been reached during the
952        matching. This also applied to assertions used as conditions.
954    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
955        assertion subpattern, including such a pattern used as a condition,
956        unpredictable results occurred, instead of the error return
959    5.  The C++ GlobalReplace function was not working like Perl for the special
960        situation when an empty string is matched. It now does the fancy magic
961        stuff that is necessary.
963    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
964        removed. (These were left over from very, very early versions of PCRE.)
966    7.  Some cosmetic changes to the code to make life easier when compiling it
967        as part of something else:
969        (a) Change DEBUG to PCRE_DEBUG.
971        (b) In pcre_compile(), rename the member of the "branch_chain" structure
972            called "current" as "current_branch", to prevent a collision with the
973            Linux macro when compiled as a kernel module.
975        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
976            prevent a collision with the Linux macro when compiled as a kernel
977            module.
979    8.  In pcre_compile() there are some checks for integer overflows that used to
980        cast potentially large values to (double). This has been changed to that
981        when building, a check for int64_t is made, and if it is found, it is used
982        instead, thus avoiding the use of floating point arithmetic. (There is no
983        other use of FP in PCRE.) If int64_t is not found, the fallback is to
984        double.
986    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
987        2005 (difference between two addresses compared to an unsigned value).
989    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
990        custom one, because of the following reported problem in Windows:
992          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
993              under Win32.
994          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
995              therefore missing the function definition.
996          - The compiler thus generates a "C" signature for the test function.
997          - The linker fails to find the "C" function.
998          - PCRE fails to configure if asked to do so against libbz2.
1000    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1001        messages were output:
1003          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1004          rerunning libtoolize, to keep the correct libtool macros in-tree.
1005          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1007        I have done both of these things.
1009    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1010        most of the time, it *can* run out if it is given a pattern that contains a
1011        runaway infinite recursion. I updated the discussion in the pcrestack man
1012        page.
1014    13. Now that we have gone to the x.xx style of version numbers, the minor
1015        version may start with zero. Using 08 or 09 is a bad idea because users
1016        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1017        interpreted as invalid octal numbers. I've updated the previous comment in
1018        configure.ac, and also added a check that gives an error if 08 or 09 are
1019        used.
1021    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1022        causing partial matching to fail when the end of the subject matched \W
1023        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1025    15. There were some discrepancies between the declarations in pcre_internal.h
1026        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1027        their definitions. The declarations used "const uschar *" and the
1028        definitions used USPTR. Even though USPTR is normally defined as "const
1029        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1030        reported that: "This difference in casting confuses some C++ compilers, for
1031        example, SunCC recognizes above declarations as different functions and
1032        generates broken code for hbpcre." I have changed the declarations to use
1033        USPTR.
1035    16. GNU libtool is named differently on some systems. The autogen.sh script now
1036        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1037        (FreeBSD).
1039    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1040        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1041        comment: "Figure out how to create a longlong from a string: strtoll and
1042        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1043        instance, but it only takes 2 args instead of 3!"
1045    18. A subtle bug concerned with back references has been fixed by a change of
1046        specification, with a corresponding code fix. A pattern such as
1047        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1048        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1049        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1050        same bug. Such groups have to be quantified to be useful, or contained
1051        inside another quantified group. (If there's no repetition, the reference
1052        can never match.) The problem arises because, having left the group and
1053        moved on to the rest of the pattern, a later failure that backtracks into
1054        the group uses the captured value from the final iteration of the group
1055        rather than the correct earlier one. I have fixed this in PCRE by forcing
1056        any group that contains a reference to itself to be an atomic group; that
1057        is, there cannot be any backtracking into it once it has completed. This is
1058        similar to recursive and subroutine calls.
1061    Version 8.00 19-Oct-09
1062    ----------------------
1064    1.  The table for translating pcre_compile() error codes into POSIX error codes
1065        was out-of-date, and there was no check on the pcre_compile() error code
1066        being within the table. This could lead to an OK return being given in
1067        error.
1069    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1070        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1071        in a Windows environment.
1073    3.  The pcregrep --count option prints the count for each file even when it is
1074        zero, as does GNU grep. However, pcregrep was also printing all files when
1075        --files-with-matches was added. Now, when both options are given, it prints
1076        counts only for those files that have at least one match. (GNU grep just
1077        prints the file name in this circumstance, but including the count seems
1078        more useful - otherwise, why use --count?) Also ensured that the
1079        combination -clh just lists non-zero counts, with no names.
1081    4.  The long form of the pcregrep -F option was incorrectly implemented as
1082        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1083        but it seems right to fix it, and I didn't think it was worth preserving
1084        the old behaviour.
1086    5.  The command line items --regex=pattern and --regexp=pattern were not
1087        recognized by pcregrep, which required --regex pattern or --regexp pattern
1088        (with a space rather than an '='). The man page documented the '=' forms,
1089        which are compatible with GNU grep; these now work.
1091    6.  No libpcreposix.pc file was created for pkg-config; there was just
1092        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1094    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1095        when UCP support is not needed, by modifying the Python script that
1096        generates it from Unicode data files. This should not matter if the module
1097        is correctly used as a library, but I received one complaint about 50K of
1098        unwanted data. My guess is that the person linked everything into his
1099        program rather than using a library. Anyway, it does no harm.
1101    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1102        was a minimum greater than 1 for a wide character in a possessive
1103        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1104        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1105        character. Chaos in the form of incorrect output or a compiling loop could
1106        result.
1108    9.  The restrictions on what a pattern can contain when partial matching is
1109        requested for pcre_exec() have been removed. All patterns can now be
1110        partially matched by this function. In addition, if there are at least two
1111        slots in the offset vector, the offset of the earliest inspected character
1112        for the match and the offset of the end of the subject are set in them when
1113        PCRE_ERROR_PARTIAL is returned.
1115    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1116        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1117        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1118        and may be more useful for multi-segment matching.
1120    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1121        used to be given if ever the end of the subject was reached; now it is
1122        given only if matching could not proceed because another character was
1123        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1124        string "Z", which now yields "no match" instead of "partial match". In the
1125        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1126        final character ended with (*FAIL).
1128    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1129        if the pattern had a "must contain" character that was already found in the
1130        earlier partial match, unless partial matching was again requested. For
1131        example, with the pattern /dog.(body)?/, the "must contain" character is
1132        "g". If the first part-match was for the string "dog", restarting with
1133        "sbody" failed. This bug has been fixed.
1135    13. The string returned by pcre_dfa_exec() after a partial match has been
1136        changed so that it starts at the first inspected character rather than the
1137        first character of the match. This makes a difference only if the pattern
1138        starts with a lookbehind assertion or \b or \B (\K is not supported by
1139        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1140        matching functions compatible, and I think it's the right thing to do.
1142    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1143        so that the demonstration program is easily available in environments where
1144        PCRE has not been installed from source.
1146    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1147        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1148        library.
1150    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1151        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1152        is not the first non-POSIX option to be added. Clearly some people find
1153        these options useful.
1155    17. If a caller to the POSIX matching function regexec() passes a non-zero
1156        value for nmatch with a NULL value for pmatch, the value of
1157        nmatch is forced to zero.
1159    18. RunGrepTest did not have a test for the availability of the -u option of
1160        the diff command, as RunTest does. It now checks in the same way as
1161        RunTest, and also checks for the -b option.
1163    19. If an odd number of negated classes containing just a single character
1164        interposed, within parentheses, between a forward reference to a named
1165        subpattern and the definition of the subpattern, compilation crashed with
1166        an internal error, complaining that it could not find the referenced
1167        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1168        [The bug was that it was starting one character too far in when skipping
1169        over the character class, thus treating the ] as data rather than
1170        terminating the class. This meant it could skip too much.]
1172    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1173        /g option in pcretest when the pattern contains \K, which makes it possible
1174        to have an empty string match not at the start, even when the pattern is
1175        anchored. Updated pcretest and pcredemo to use this option.
1177    21. If the maximum number of capturing subpatterns in a recursion was greater
1178        than the maximum at the outer level, the higher number was returned, but
1179        with unset values at the outer level. The correct (outer level) value is
1180        now given.
1182    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1183        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1184        make it do so. The string so far is captured, making this feature
1185        compatible with Perl.
1187    23. The tests have been re-organized, adding tests 11 and 12, to make it
1188        possible to check the Perl 5.10 features against Perl 5.10.
1190    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1191        pattern matches a fixed length string. PCRE did not allow this; now it
1192        does. Neither allows recursion.
1194    25. I finally figured out how to implement a request to provide the minimum
1195        length of subject string that was needed in order to match a given pattern.
1196        (It was back references and recursion that I had previously got hung up
1197        on.) This code has now been added to pcre_study(); it finds a lower bound
1198        to the length of subject needed. It is not necessarily the greatest lower
1199        bound, but using it to avoid searching strings that are too short does give
1200        some useful speed-ups. The value is available to calling programs via
1201        pcre_fullinfo().
1203    26. While implementing 25, I discovered to my embarrassment that pcretest had
1204        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1205        study optimizations had never been tested with that matching function.
1206        Oops. What is worse, even when it was passed study data, there was a bug in
1207        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1208        were also very few tests of studied patterns with pcre_dfa_exec().
1210    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1211        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1212        on the other side of the coin, they are no longer allowed to have different
1213        names, because these cannot be distinguished in PCRE, and this has caused
1214        confusion. (This is a difference from Perl.)
1216    28. When duplicate subpattern names are present (necessarily with different
1217        numbers, as required by 27 above), and a test is made by name in a
1218        conditional pattern, either for a subpattern having been matched, or for
1219        recursion in such a pattern, all the associated numbered subpatterns are
1220        tested, and the overall condition is true if the condition is true for any
1221        one of them. This is the way Perl works, and is also more like the way
1222        testing by number works.
1225    Version 7.9 11-Apr-09
1226    ---------------------
1228    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1229        (pcretest), all targets were linked against these libraries. This included
1230        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1231        libraries. This caused unwanted dependencies to be created. This problem
1232        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1233        pcretest is linked with readline.
1235    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1236        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1237        moved outside it again, because FALSE and TRUE are already defined in AIX,
1238        but BOOL is not.
1240    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1241        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1243    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1244        hyphens) following file names and line numbers when outputting matching
1245        lines. This is not true; no spaces are inserted. I have also clarified the
1246        wording for the --colour (or --color) option.
1248    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1249        was not coloured; this is different to GNU grep, so I have changed it to be
1250        the same.
1252    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1253        each matching line was coloured. Now it goes on to look for further matches
1254        of any of the test patterns, which is the same behaviour as GNU grep.
1256    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1257        doesn't make sense to accept an empty string match in pcregrep, so I have
1258        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1259        seems to be how GNU grep behaves.
1261    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1262        start or after a newline", because the conditional assertion was not being
1263        correctly handled. The rule now is that both the assertion and what follows
1264        in the first alternative must satisfy the test.
1266    9.  If auto-callout was enabled in a pattern with a conditional group whose
1267        condition was an assertion, PCRE could crash during matching, both with
1268        pcre_exec() and pcre_dfa_exec().
1270    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1271        used for matching.
1273    11. Unicode property support in character classes was not working for
1274        characters (bytes) greater than 127 when not in UTF-8 mode.
1276    12. Added the -M command line option to pcretest.
1278    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1280    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1282    16. Added comments and documentation about mis-use of no_arg in the C++
1283        wrapper.
1285    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1286        from Martin Jerabek that uses macro names for all relevant character and
1287        string constants.
1289    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1290        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1291        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1292        these, but not everybody uses configure.
1294    19. A conditional group that had only one branch was not being correctly
1295        recognized as an item that could match an empty string. This meant that an
1296        enclosing group might also not be so recognized, causing infinite looping
1297        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1298        with the subject "ab", where knowledge that the repeated group can match
1299        nothing is needed in order to break the loop.
1301    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1302        exec(), but without supplying a callout function, matching went wrong.
1304    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1305        leak if the size of the offset vector was greater than 30. When the vector
1306        is smaller, the saved offsets during recursion go onto a local stack
1307        vector, but for larger vectors malloc() is used. It was failing to free
1308        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1309        error, in fact).
1311    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1312        heapframe that is used only when UTF-8 support is enabled. This caused no
1313        problem, but was untidy.
1315    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1316        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1317        included within another project.
1319    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1320        slightly modified by me:
1322          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1323              not building pcregrep.
1325          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1326              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1328    25. Forward references, both numeric and by name, in patterns that made use of
1329        duplicate group numbers, could behave incorrectly or give incorrect errors,
1330        because when scanning forward to find the reference group, PCRE was not
1331        taking into account the duplicate group numbers. A pattern such as
1332        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1334    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1335        the feature of a custom pointer more persuasive (as requested by a user).
1337    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1338        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1339        pre-defined.
1341    28. Added support for (*UTF8) at the start of a pattern.
1343    29. Arrange for flags added by the "release type" setting in CMake to be shown
1344        in the configuration summary.
1347    Version 7.8 05-Sep-08
1348  ---------------------  ---------------------
1350  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
# Line 31  Version 8.0 02 Jul-08 Line 1374  Version 8.0 02 Jul-08
1375  7.  Added two (int) casts to pcregrep when printing the difference of two  7.  Added two (int) casts to pcregrep when printing the difference of two
1376      pointers, in case they are 64-bit values.      pointers, in case they are 64-bit values.
1378  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1379      test 2 if it fails.      test 2 if it fails.
1381  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1382      and a #define of that name to empty if it is not externally set. This is to      and a #define of that name to empty if it is not externally set. This is to
1383      allow users of MSVC to set it if necessary.      allow users of MSVC to set it if necessary.
1385  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1386      the convenience functions in the pcre_get.c source file.      the convenience functions in the pcre_get.c source file.
1388    11. An option change at the start of a pattern that had top-level alternatives
1389        could cause overwriting and/or a crash. This command provoked a crash in
1390        some environments:
1392          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1394        This potential security problem was recorded as CVE-2008-2371.
1396    12. For a pattern where the match had to start at the beginning or immediately
1397        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1398        pcre_dfa_exec() could read past the end of the passed subject if there was
1399        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1400        pcretest so that it places the subject at the end of its malloc-ed buffer.
1402    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1403        exec() might read past the end of the data buffer in UTF-8 mode.
1405    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1406        the data contained the byte 0x85 as part of a UTF-8 character within its
1407        first line. This applied both to normal and DFA matching.
1409    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1410        /^[^d]*?$/8 failed to match "abc".
1412    16. Added a missing copyright notice to pcrecpp_internal.h.
1414    17. Make it more clear in the documentation that values returned from
1415        pcre_exec() in ovector are byte offsets, not character counts.
1417    18. Tidied a few places to stop certain compilers from issuing warnings.
1419    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1420        supplied by Stefan Weber. I made a further small update for 7.8 because
1421        there is a change of source arrangements: the pcre_searchfuncs.c module is
1422        replaced by pcre_ucd.c.
1425  Version 7.7 07-May-08  Version 7.7 07-May-08
1426  ---------------------  ---------------------

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