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

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