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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.1 12-Mar-07  Version 8.21
5    ------------
7    1.  Updating the JIT compiler.
9    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
10        are added as well.
12    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
13        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
14        calling _pcre_jit_exec. Some extra comments are added.
16    4.  Mark settings inside atomic groups that do not contain any capturing
17        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
18        was introduced by change 18 for 8.20.
20    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
21        ECMA-262 standard.
23    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
24        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
25        This bug was probably introduced by change 9 of 8.13.
27    7.  While fixing 6 above, I noticed that a number of other items were being
28        incorrectly rejected as "not fixed length". This arose partly because newer
29        opcodes had not been added to the fixed-length checking code. I have (a)
30        corrected the bug and added tests for these items, and (b) arranged for an
31        error to occur if an unknown opcode is encountered while checking for fixed
32        length instead of just assuming "not fixed length". The items that were
33        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
34        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
35        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
37    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
38        being incorrectly compiled and would have given unpredicatble results.
40    9.  A possessively repeated subpattern with minimum repeat count greater than
41        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
42        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
43        the first (A) could occur when it should not.
45    10. Add a cast and remove a redundant test from the code.
48    Version 8.20 21-Oct-2011
49    ------------------------
51    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
52        a POSIX class. After further experiments with Perl, which convinced me that
53        Perl has bugs and confusions, a closing square bracket is no longer allowed
54        in a POSIX name. This bug also affected patterns with classes that started
55        with full stops.
57    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
58        captured substring, but while checking the failing first alternative,
59        substring 1 is temporarily captured. If the output vector supplied to
60        pcre_exec() was not big enough for this capture, the yield of the function
61        was still zero ("insufficient space for captured substrings"). This cannot
62        be totally fixed without adding another stack variable, which seems a lot
63        of expense for a edge case. However, I have improved the situation in cases
64        such as /(a)(b)x|abc/ matched against "abc", where the return code
65        indicates that fewer than the maximum number of slots in the ovector have
66        been set.
68    3.  Related to (2) above: when there are more back references in a pattern than
69        slots in the output vector, pcre_exec() uses temporary memory during
70        matching, and copies in the captures as far as possible afterwards. It was
71        using the entire output vector, but this conflicts with the specification
72        that only 2/3 is used for passing back captured substrings. Now it uses
73        only the first 2/3, for compatibility. This is, of course, another edge
74        case.
76    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
77        main code base, and can be used by building with --enable-jit. When this is
78        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
79        runtime --no-jit option is given.
81    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
82        ovector, the return from the function was zero, implying that there were
83        other matches that did not fit. The correct "exactly full" value is now
84        returned.
86    6.  If a subpattern that was called recursively or as a subroutine contained
87        (*PRUNE) or any other control that caused it to give a non-standard return,
88        invalid errors such as "Error -26 (nested recursion at the same subject
89        position)" or even infinite loops could occur.
91    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
92        computing the minimum length on reaching *ACCEPT, and so ended up with the
93        wrong value of 1 rather than 0. Further investigation indicates that
94        computing a minimum subject length in the presence of *ACCEPT is difficult
95        (think back references, subroutine calls), and so I have changed the code
96        so that no minimum is registered for a pattern that contains *ACCEPT.
98    8.  If (*THEN) was present in the first (true) branch of a conditional group,
99        it was not handled as intended. [But see 16 below.]
101    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
102        Sheri Pierce.
104    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
105        the first byte in a match must be "a".
107    11. Change 17 for 8.13 increased the recursion depth for patterns like
108        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
109        pattern contains any instances of (*THEN). If it does not, the old
110        optimizations are restored. It would be nice to do this on a per-group
111        basis, but at the moment that is not feasible.
113    12. In some environments, the output of pcretest -C is CRLF terminated. This
114        broke RunTest's code that checks for the link size. A single white space
115        character after the value is now allowed for.
117    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
118        For "fr", it uses the Windows-specific input and output files.
120    14. If (*THEN) appeared in a group that was called recursively or as a
121        subroutine, it did not work as intended. [But see next item.]
123    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
124        pattern fragments (but not containing any | characters). If A and B are
125        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
126        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
127        D. In other words, Perl considers parentheses that do not contain any |
128        characters to be part of a surrounding alternative, whereas PCRE was
129        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
130        differently. PCRE now behaves in the same way as Perl, except in the case
131        of subroutine/recursion calls such as (?1) which have in any case always
132        been different (but PCRE had them first :-).
134    16. Related to 15 above: Perl does not treat the | in a conditional group as
135        creating alternatives. Such a group is treated in the same way as an
136        ordinary group without any | characters when processing (*THEN). PCRE has
137        been changed to match Perl's behaviour.
139    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
140        RunGrepTest script failed.
142    18. Change 22 for version 13 caused atomic groups to use more stack. This is
143        inevitable for groups that contain captures, but it can lead to a lot of
144        stack use in large patterns. The old behaviour has been restored for atomic
145        groups that do not contain any capturing parentheses.
147    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
148        suppress the check for a minimum subject length at run time. (If it was
149        given to pcre_exec() or pcre_dfa_exec() it did work.)
151    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
152        fail to work when decoding hex characters in data strings in EBCDIC
153        environments.
155    21. It appears that in at least one Mac OS environment, the isxdigit() function
156        is implemented as a macro that evaluates to its argument more than once,
157        contravening the C 90 Standard (I haven't checked a later standard). There
158        was an instance in pcretest which caused it to go wrong when processing
159        \x{...} escapes in subject strings. The has been rewritten to avoid using
160        things like p++ in the argument of isxdigit().
163    Version 8.13 16-Aug-2011
164    ------------------------
166    1.  The Unicode data tables have been updated to Unicode 6.0.0.
168    2.  Two minor typos in pcre_internal.h have been fixed.
170    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
171        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
172        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
174    4.  There were a number of related bugs in the code for matching backrefences
175        caselessly in UTF-8 mode when codes for the characters concerned were
176        different numbers of bytes. For example, U+023A and U+2C65 are an upper
177        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
178        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
179        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
180        2-byte code at the end of the subject (it thought there wasn't enough data
181        left).
183    5.  Comprehensive information about what went wrong is now returned by
184        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
185        as the output vector has at least 2 elements. The offset of the start of
186        the failing character and a reason code are placed in the vector.
188    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
189        now returned is for the first byte of the failing character, instead of the
190        last byte inspected. This is an incompatible change, but I hope it is small
191        enough not to be a problem. It makes the returned offset consistent with
192        pcre_exec() and pcre_dfa_exec().
194    7.  pcretest now gives a text phrase as well as the error number when
195        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
196        failure, the offset and reason code are output.
198    8.  When \R was used with a maximizing quantifier it failed to skip backwards
199        over a \r\n pair if the subsequent match failed. Instead, it just skipped
200        back over a single character (\n). This seems wrong (because it treated the
201        two characters as a single entity when going forwards), conflicts with the
202        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
203        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
204        has been changed.
206    9.  Some internal refactoring has changed the processing so that the handling
207        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
208        time (the PCRE_DOTALL option was changed this way some time ago: version
209        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
210        which was always a bit of a fudge. It also means that there is one less
211        argument for the match() function, which reduces its stack requirements
212        slightly. This change also fixes an incompatibility with Perl: the pattern
213        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
215    10. More internal refactoring has drastically reduced the number of recursive
216        calls to match() for possessively repeated groups such as (abc)++ when
217        using pcre_exec().
219    11. While implementing 10, a number of bugs in the handling of groups were
220        discovered and fixed:
222        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
223        (a|)*(?1) gave a compile-time internal error.
224        ((a|)+)+  did not notice that the outer group could match an empty string.
225        (^a|^)+   was not marked as anchored.
226        (.*a|.*)+ was not marked as matching at start or after a newline.
228    12. Yet more internal refactoring has removed another argument from the match()
229        function. Special calls to this function are now indicated by setting a
230        value in a variable in the "match data" data block.
232    13. Be more explicit in pcre_study() instead of relying on "default" for
233        opcodes that mean there is no starting character; this means that when new
234        ones are added and accidentally left out of pcre_study(), testing should
235        pick them up.
237    14. The -s option of pcretest has been documented for ages as being an old
238        synonym of -m (show memory usage). I have changed it to mean "force study
239        for every regex", that is, assume /S for every regex. This is similar to -i
240        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
241        using it. It makes it easier to run collections of tests with and without
242        study enabled, and thereby test pcre_study() more easily. All the standard
243        tests are now run with and without -s (but some patterns can be marked as
244        "never study" - see 20 below).
246    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
247        restoration of the capturing data to the outer values was not happening
248        correctly.
250    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
251        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
252        pattern had matched an empty string, and so incorrectly returned a no
253        match.
255    17. There was optimizing code for the last branch of non-capturing parentheses,
256        and also for the obeyed branch of a conditional subexpression, which used
257        tail recursion to cut down on stack usage. Unfortunately, now that there is
258        the possibility of (*THEN) occurring in these branches, tail recursion is
259        no longer possible because the return has to be checked for (*THEN). These
260        two optimizations have therefore been removed. [But see 8.20/11 above.]
262    18. If a pattern containing \R was studied, it was assumed that \R always
263        matched two bytes, thus causing the minimum subject length to be
264        incorrectly computed because \R can also match just one byte.
266    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
267        was incorrectly computed.
269    20. If /S is present twice on a test pattern in pcretest input, it now
270        *disables* studying, thereby overriding the use of -s on the command line
271        (see 14 above). This is necessary for one or two tests to keep the output
272        identical in both cases.
274    21. When (*ACCEPT) was used in an assertion that matched an empty string and
275        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
277    22. When an atomic group that contained a capturing parenthesis was
278        successfully matched, but the branch in which it appeared failed, the
279        capturing was not being forgotten if a higher numbered group was later
280        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
281        group 1 to "a", when in fact it should be unset. This applied to multi-
282        branched capturing and non-capturing groups, repeated or not, and also to
283        positive assertions (capturing in negative assertions does not happen
284        in PCRE) and also to nested atomic groups.
286    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
287        subject after a captured substring, to make it easier to tell which of a
288        number of identical substrings has been captured.
290    24. The way atomic groups are processed by pcre_exec() has been changed so that
291        if they are repeated, backtracking one repetition now resets captured
292        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
293        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
294        "aaa". Previously, it would have been "a". As part of this code
295        refactoring, the way recursive calls are handled has also been changed.
297    25. If an assertion condition captured any substrings, they were not passed
298        back unless some other capturing happened later. For example, if
299        (?(?=(a))a) was matched against "a", no capturing was returned.
301    26. When studying a pattern that contained subroutine calls or assertions,
302        the code for finding the minimum length of a possible match was handling
303        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
304        group 1 called group 2 while simultaneously a separate group 2 called group
305        1). A stack overflow occurred in this case. I have fixed this by limiting
306        the recursion depth to 10.
308    27. Updated RunTest.bat in the distribution to the version supplied by Tom
309        Fortmann. This supports explicit test numbers on the command line, and has
310        argument validation and error reporting.
312    28. An instance of \X with an unlimited repeat could fail if at any point the
313        first character it looked at was a mark character.
315    29. Some minor code refactoring concerning Unicode properties and scripts
316        should reduce the stack requirement of match() slightly.
318    30. Added the '=' option to pcretest to check the setting of unused capturing
319        slots at the end of the pattern, which are documented as being -1, but are
320        not included in the return count.
322    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
323        compiled something random. Now it gives a compile-time error (as does
324        Perl).
326    32. A *MARK encountered during the processing of a positive assertion is now
327        recorded and passed back (compatible with Perl).
329    33. If --only-matching or --colour was set on a pcregrep call whose pattern
330        had alternative anchored branches, the search for a second match in a line
331        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
332        matched the line "0102" twice. The same bug affected patterns that started
333        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
334        twice.
336    34. Previously, PCRE did not allow quantification of assertions. However, Perl
337        does, and because of capturing effects, quantifying parenthesized
338        assertions may at times be useful. Quantifiers are now allowed for
339        parenthesized assertions.
341    35. A minor code tidy in pcre_compile() when checking options for \R usage.
343    36. \g was being checked for fancy things in a character class, when it should
344        just be a literal "g".
346    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
347        appearance of a nested POSIX class supersedes an apparent external class.
348        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
349        unescaped square brackets may also appear as part of class names. For
350        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
351        more like Perl. (But see 8.20/1 above.)
353    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
354        was because it thought it was \N{name}, which is not supported).
356    39. Add minix to OS list not supporting the -S option in pcretest.
358    40. PCRE tries to detect cases of infinite recursion at compile time, but it
359        cannot analyze patterns in sufficient detail to catch mutual recursions
360        such as ((?1))((?2)). There is now a runtime test that gives an error if a
361        subgroup is called recursively as a subpattern for a second time at the
362        same position in the subject string. In previous releases this might have
363        been caught by the recursion limit, or it might have run out of stack.
365    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
366        happen only once. PCRE was, however incorrectly giving a compile time error
367        "recursive call could loop indefinitely" because it cannot analyze the
368        pattern in sufficient detail. The compile time test no longer happens when
369        PCRE is compiling a conditional subpattern, but actual runaway loops are
370        now caught at runtime (see 40 above).
372    42. It seems that Perl allows any characters other than a closing parenthesis
373        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
374        has been changed to be the same.
376    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
377        as not to get warnings when autogen.sh is called. Also changed
378        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
380    44. To help people who use pcregrep to scan files containing exceedingly long
381        lines, the following changes have been made:
383        (a) The default value of the buffer size parameter has been increased from
384            8K to 20K. (The actual buffer used is three times this size.)
386        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
387            PCRE is built.
389        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
390            to be set at run time.
392        (d) Numerical values in pcregrep options can be followed by K or M, for
393            example --buffer-size=50K.
395        (e) If a line being scanned overflows pcregrep's buffer, an error is now
396            given and the return code is set to 2.
398    45. Add a pointer to the latest mark to the callout data block.
400    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
401        partial match of an empty string instead of no match. This was specific to
402        the use of ".".
404    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
405        complete match instead of a partial match. This bug was dependent on both
406        the PCRE_UTF8 and PCRE_DOTALL options being set.
408    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
409        starting byte set, because \b was not being ignored.
412    Version 8.12 15-Jan-2011
413    ------------------------
415    1.  Fixed some typos in the markup of the man pages, and wrote a script that
416        checks for such things as part of the documentation building process.
418    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
419        --match-limit and --recursion-limit options (added for 8.11). In
420        particular, this made one of the standard tests fail. (The integer value
421        went into the wrong half of a long int.)
423    3.  If the --colour option was given to pcregrep with -v (invert match), it
424        did strange things, either producing crazy output, or crashing. It should,
425        of course, ignore a request for colour when reporting lines that do not
426        match.
428    4.  Another pcregrep bug caused similar problems if --colour was specified with
429        -M (multiline) and the pattern match finished with a line ending.
431    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
432        matched in multiline mode, the following line was shown as part of the
433        match. This seems wrong, so I have changed it.
435    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
436        the check for further matches in the same line (so they could be coloured)
437        to overrun the end of the current line. If another match was found, it was
438        incorrectly shown (and then shown again when found in the next line).
440    7.  If pcregrep was compiled under Windows, there was a reference to the
441        function pcregrep_exit() before it was defined. I am assuming this was
442        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
443        reported by a user. I've moved the definition above the reference.
446    Version 8.11 10-Dec-2010
447    ------------------------
449    1.  (*THEN) was not working properly if there were untried alternatives prior
450        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
451        backtracked to try for "b" instead of moving to the next alternative branch
452        at the same level (in this case, to look for "c"). The Perl documentation
453        is clear that when (*THEN) is backtracked onto, it goes to the "next
454        alternative in the innermost enclosing group".
456    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
457        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
458        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
459        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
460        (*THEN).
462    3.  If \s appeared in a character class, it removed the VT character from
463        the class, even if it had been included by some previous item, for example
464        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
465        of \s, but is part of the POSIX "space" class.)
467    4.  A partial match never returns an empty string (because you can always
468        match an empty string at the end of the subject); however the checking for
469        an empty string was starting at the "start of match" point. This has been
470        changed to the "earliest inspected character" point, because the returned
471        data for a partial match starts at this character. This means that, for
472        example, /(?<=abc)def/ gives a partial match for the subject "abc"
473        (previously it gave "no match").
475    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
476        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
477        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
478        has an implication that the given string is incomplete (because a partial
479        match is preferred over a full match). For this reason, these items now
480        give a partial match in this situation. [Aside: previously, the one case
481        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
482        match rather than a full match, which was wrong by the old rules, but is
483        now correct.]
485    6.  There was a bug in the handling of #-introduced comments, recognized when
486        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
487        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
488        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
489        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
490        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
491        places in pcre_compile().
493    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
494        comments when looking ahead for named forward references to subpatterns,
495        the only newline sequence it recognized was NL. It now handles newlines
496        according to the set newline convention.
498    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
499        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
500        cater for a lack of strerror(). These oversights have been fixed.
502    9.  Added --match-limit and --recursion-limit to pcregrep.
504    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
506    11. When the -o option was used, pcregrep was setting a return code of 1, even
507        when matches were found, and --line-buffered was not being honoured.
509    12. Added an optional parentheses number to the -o and --only-matching options
510        of pcregrep.
512    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
513        can match an empty string. The code to do it in pcretest and pcredemo
514        needed fixing:
516        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
517            only one byte after an empty string match just before CRLF (this case
518            just got forgotten; "any" and "anycrlf" were OK).
520        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
521            mode when an empty string match preceded an ASCII character followed by
522            a non-ASCII character. (The code for advancing by one character rather
523            than one byte was nonsense.)
525        (c) The pcredemo.c sample program did not have any code at all to handle
526            the cases when CRLF is a valid newline sequence.
528    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
529        as a starting offset was within the subject string. There is now a new
530        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
531        negative or greater than the length of the string. In order to test this,
532        pcretest is extended to allow the setting of negative starting offsets.
534    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
535        starting offset points to the beginning of a UTF-8 character was
536        unnecessarily clumsy. I tidied it up.
538    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
539        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
541    17. Nobody had reported that the --include_dir option, which was added in
542        release 7.7 should have been called --include-dir (hyphen, not underscore)
543        for compatibility with GNU grep. I have changed it to --include-dir, but
544        left --include_dir as an undocumented synonym, and the same for
545        --exclude-dir, though that is not available in GNU grep, at least as of
546        release 2.5.4.
548    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
549        characters from a string of bytes) have been redefined so as not to use
550        loops, in order to improve performance in some environments. At the same
551        time, I abstracted some of the common code into auxiliary macros to save
552        repetition (this should not affect the compiled code).
554    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
555        compile-time error is now given if \c is not followed by an ASCII
556        character, that is, a byte less than 128. (In EBCDIC mode, the code is
557        different, and any byte value is allowed.)
559    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
560        START_OPTIMIZE option, which is now allowed at compile time - but just
561        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
562        to pcregrep and other applications that have no direct access to PCRE
563        options. The new /Y option in pcretest sets this option when calling
564        pcre_compile().
566    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
567        back references. Groups containing recursive back references were forced to
568        be atomic by that change, but in the case of named groups, the amount of
569        memory required was incorrectly computed, leading to "Failed: internal
570        error: code overflow". This has been fixed.
572    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
573        pcretest.c, to avoid build problems in some Borland environments.
576    Version 8.10 25-Jun-2010
577    ------------------------
579    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
580        THEN.
582    2.  (*ACCEPT) was not working when inside an atomic group.
584    3.  Inside a character class, \B is treated as a literal by default, but
585        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
586        causes the error). The code is unchanged, but I tidied the documentation.
588    4.  Inside a character class, PCRE always treated \R and \X as literals,
589        whereas Perl faults them if its -w option is set. I have changed PCRE so
590        that it faults them when PCRE_EXTRA is set.
592    5.  Added support for \N, which always matches any character other than
593        newline. (It is the same as "." when PCRE_DOTALL is not set.)
595    6.  When compiling pcregrep with newer versions of gcc which may have
596        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
597        declared with attribute warn_unused_result" were given. Just casting the
598        result to (void) does not stop the warnings; a more elaborate fudge is
599        needed. I've used a macro to implement this.
601    7.  Minor change to pcretest.c to avoid a compiler warning.
603    8.  Added four artifical Unicode properties to help with an option to make
604        \s etc use properties (see next item). The new properties are: Xan
605        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
607    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
608        use Unicode properties. (*UCP) at the start of a pattern can be used to set
609        this option. Modified pcretest to add /W to test this facility. Added
610        REG_UCP to make it available via the POSIX interface.
612    10. Added --line-buffered to pcregrep.
614    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
615        studied, and the match started with a letter with a code point greater than
616        127 whose first byte was different to the first byte of the other case of
617        the letter, the other case of this starting letter was not recognized
618        (#976).
620    12. If a pattern that was studied started with a repeated Unicode property
621        test, for example, \p{Nd}+, there was the theoretical possibility of
622        setting up an incorrect bitmap of starting bytes, but fortunately it could
623        not have actually happened in practice until change 8 above was made (it
624        added property types that matched character-matching opcodes).
626    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
627        possible starting bytes for non-anchored patterns.
629    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
630        \R, and also a number of cases that involve Unicode properties, both
631        explicit and implicit when PCRE_UCP is set.
633    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
634        input, it could crash or give wrong results if characters with values
635        greater than 0xc0 were present in the subject string. (Detail: it assumed
636        UTF-8 input when processing these items.)
638    16. Added a lot of (int) casts to avoid compiler warnings in systems where
639        size_t is 64-bit (#991).
641    17. Added a check for running out of memory when PCRE is compiled with
642        --disable-stack-for-recursion (#990).
644    18. If the last data line in a file for pcretest does not have a newline on
645        the end, a newline was missing in the output.
647    19. The default pcre_chartables.c file recognizes only ASCII characters (values
648        less than 128) in its various bitmaps. However, there is a facility for
649        generating tables according to the current locale when PCRE is compiled. It
650        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
651        characters, are recognized by isspace() and therefore were getting set in
652        these tables, and indeed these tables seem to approximate to ISO 8859. This
653        caused a problem in UTF-8 mode when pcre_study() was used to create a list
654        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
655        which of course cannot start UTF-8 characters. I have changed the code so
656        that only real ASCII characters (less than 128) and the correct starting
657        bytes for UTF-8 encodings are set for characters greater than 127 when in
658        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
659        altogether.)
661    20. Added the /T option to pcretest so as to be able to run tests with non-
662        standard character tables, thus making it possible to include the tests
663        used for 19 above in the standard set of tests.
665    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
666        reference to a subpattern the other side of a comment that contains an
667        opening parenthesis caused either an internal compiling error, or a
668        reference to the wrong subpattern.
671    Version 8.02 19-Mar-2010
672    ------------------------
674    1.  The Unicode data tables have been updated to Unicode 5.2.0.
676    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
677        configured.
679    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
680        original author of that file, following a query about its status.
682    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
683        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
685    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
686        quantifier applied to a forward-referencing subroutine call, could compile
687        incorrect code or give the error "internal error: previously-checked
688        referenced subpattern not found".
690    6.  Both MS Visual Studio and Symbian OS have problems with initializing
691        variables to point to external functions. For these systems, therefore,
692        pcre_malloc etc. are now initialized to local functions that call the
693        relevant global functions.
695    7.  There were two entries missing in the vectors called coptable and poptable
696        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
697        I've fixed the data, and added a kludgy way of testing at compile time that
698        the lengths are correct (equal to the number of opcodes).
700    8.  Following on from 7, I added a similar kludge to check the length of the
701        eint vector in pcreposix.c.
703    9.  Error texts for pcre_compile() are held as one long string to avoid too
704        much relocation at load time. To find a text, the string is searched,
705        counting zeros. There was no check for running off the end of the string,
706        which could happen if a new error number was added without updating the
707        string.
709    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
711    11. \K was not working if it appeared in an atomic group or in a group that
712        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
713        \K is "not well defined" if used in an assertion. PCRE now accepts it if
714        the assertion is positive, but not if it is negative.
716    12. Change 11 fortuitously reduced the size of the stack frame used in the
717        "match()" function of pcre_exec.c by one pointer. Forthcoming
718        implementation of support for (*MARK) will need an extra pointer on the
719        stack; I have reserved it now, so that the stack frame size does not
720        decrease.
722    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
723        item in branch that calls a recursion is a subroutine call - as in the
724        second branch in the above example - was incorrectly given the compile-
725        time error "recursive call could loop indefinitely" because pcre_compile()
726        was not correctly checking the subroutine for matching a non-empty string.
728    14. The checks for overrunning compiling workspace could trigger after an
729        overrun had occurred. This is a "should never occur" error, but it can be
730        triggered by pathological patterns such as hundreds of nested parentheses.
731        The checks now trigger 100 bytes before the end of the workspace.
733    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
736    Version 8.01 19-Jan-2010
737    ------------------------
739    1.  If a pattern contained a conditional subpattern with only one branch (in
740        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
741        computed the wrong minimum data length (which is of course zero for such
742        subpatterns). This could cause incorrect "no match" results.
744    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
745        the pattern is reset in the first branch, pcre_compile() failed with
746        "internal error: code overflow at offset...". This happened only when
747        the reset was to the original external option setting. (An optimization
748        abstracts leading options settings into an external setting, which was the
749        cause of this.)
751    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
752        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
753        assertion pattern did not match (meaning that the assertion was true), it
754        was incorrectly treated as false if the SKIP had been reached during the
755        matching. This also applied to assertions used as conditions.
757    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
758        assertion subpattern, including such a pattern used as a condition,
759        unpredictable results occurred, instead of the error return
762    5.  The C++ GlobalReplace function was not working like Perl for the special
763        situation when an empty string is matched. It now does the fancy magic
764        stuff that is necessary.
766    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
767        removed. (These were left over from very, very early versions of PCRE.)
769    7.  Some cosmetic changes to the code to make life easier when compiling it
770        as part of something else:
772        (a) Change DEBUG to PCRE_DEBUG.
774        (b) In pcre_compile(), rename the member of the "branch_chain" structure
775            called "current" as "current_branch", to prevent a collision with the
776            Linux macro when compiled as a kernel module.
778        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
779            prevent a collision with the Linux macro when compiled as a kernel
780            module.
782    8.  In pcre_compile() there are some checks for integer overflows that used to
783        cast potentially large values to (double). This has been changed to that
784        when building, a check for int64_t is made, and if it is found, it is used
785        instead, thus avoiding the use of floating point arithmetic. (There is no
786        other use of FP in PCRE.) If int64_t is not found, the fallback is to
787        double.
789    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
790        2005 (difference between two addresses compared to an unsigned value).
792    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
793        custom one, because of the following reported problem in Windows:
795          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
796              under Win32.
797          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
798              therefore missing the function definition.
799          - The compiler thus generates a "C" signature for the test function.
800          - The linker fails to find the "C" function.
801          - PCRE fails to configure if asked to do so against libbz2.
803    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
804        messages were output:
806          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
807          rerunning libtoolize, to keep the correct libtool macros in-tree.
808          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
810        I have done both of these things.
812    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
813        most of the time, it *can* run out if it is given a pattern that contains a
814        runaway infinite recursion. I updated the discussion in the pcrestack man
815        page.
817    13. Now that we have gone to the x.xx style of version numbers, the minor
818        version may start with zero. Using 08 or 09 is a bad idea because users
819        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
820        interpreted as invalid octal numbers. I've updated the previous comment in
821        configure.ac, and also added a check that gives an error if 08 or 09 are
822        used.
824    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
825        causing partial matching to fail when the end of the subject matched \W
826        in a UTF-8 pattern where \W was quantified with a minimum of 3.
828    15. There were some discrepancies between the declarations in pcre_internal.h
829        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
830        their definitions. The declarations used "const uschar *" and the
831        definitions used USPTR. Even though USPTR is normally defined as "const
832        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
833        reported that: "This difference in casting confuses some C++ compilers, for
834        example, SunCC recognizes above declarations as different functions and
835        generates broken code for hbpcre." I have changed the declarations to use
836        USPTR.
838    16. GNU libtool is named differently on some systems. The autogen.sh script now
839        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
840        (FreeBSD).
842    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
843        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
844        comment: "Figure out how to create a longlong from a string: strtoll and
845        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
846        instance, but it only takes 2 args instead of 3!"
848    18. A subtle bug concerned with back references has been fixed by a change of
849        specification, with a corresponding code fix. A pattern such as
850        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
851        refers, was giving matches when it shouldn't. For example, xa=xaaa would
852        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
853        same bug. Such groups have to be quantified to be useful, or contained
854        inside another quantified group. (If there's no repetition, the reference
855        can never match.) The problem arises because, having left the group and
856        moved on to the rest of the pattern, a later failure that backtracks into
857        the group uses the captured value from the final iteration of the group
858        rather than the correct earlier one. I have fixed this in PCRE by forcing
859        any group that contains a reference to itself to be an atomic group; that
860        is, there cannot be any backtracking into it once it has completed. This is
861        similar to recursive and subroutine calls.
864    Version 8.00 19-Oct-09
865    ----------------------
867    1.  The table for translating pcre_compile() error codes into POSIX error codes
868        was out-of-date, and there was no check on the pcre_compile() error code
869        being within the table. This could lead to an OK return being given in
870        error.
872    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
873        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
874        in a Windows environment.
876    3.  The pcregrep --count option prints the count for each file even when it is
877        zero, as does GNU grep. However, pcregrep was also printing all files when
878        --files-with-matches was added. Now, when both options are given, it prints
879        counts only for those files that have at least one match. (GNU grep just
880        prints the file name in this circumstance, but including the count seems
881        more useful - otherwise, why use --count?) Also ensured that the
882        combination -clh just lists non-zero counts, with no names.
884    4.  The long form of the pcregrep -F option was incorrectly implemented as
885        --fixed_strings instead of --fixed-strings. This is an incompatible change,
886        but it seems right to fix it, and I didn't think it was worth preserving
887        the old behaviour.
889    5.  The command line items --regex=pattern and --regexp=pattern were not
890        recognized by pcregrep, which required --regex pattern or --regexp pattern
891        (with a space rather than an '='). The man page documented the '=' forms,
892        which are compatible with GNU grep; these now work.
894    6.  No libpcreposix.pc file was created for pkg-config; there was just
895        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
897    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
898        when UCP support is not needed, by modifying the Python script that
899        generates it from Unicode data files. This should not matter if the module
900        is correctly used as a library, but I received one complaint about 50K of
901        unwanted data. My guess is that the person linked everything into his
902        program rather than using a library. Anyway, it does no harm.
904    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
905        was a minimum greater than 1 for a wide character in a possessive
906        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
907        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
908        character. Chaos in the form of incorrect output or a compiling loop could
909        result.
911    9.  The restrictions on what a pattern can contain when partial matching is
912        requested for pcre_exec() have been removed. All patterns can now be
913        partially matched by this function. In addition, if there are at least two
914        slots in the offset vector, the offset of the earliest inspected character
915        for the match and the offset of the end of the subject are set in them when
916        PCRE_ERROR_PARTIAL is returned.
918    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
919        synonymous with PCRE_PARTIAL, for backwards compatibility, and
920        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
921        and may be more useful for multi-segment matching.
923    11. Partial matching with pcre_exec() is now more intuitive. A partial match
924        used to be given if ever the end of the subject was reached; now it is
925        given only if matching could not proceed because another character was
926        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
927        string "Z", which now yields "no match" instead of "partial match". In the
928        case of pcre_dfa_exec(), "no match" is given if every matching path for the
929        final character ended with (*FAIL).
931    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
932        if the pattern had a "must contain" character that was already found in the
933        earlier partial match, unless partial matching was again requested. For
934        example, with the pattern /dog.(body)?/, the "must contain" character is
935        "g". If the first part-match was for the string "dog", restarting with
936        "sbody" failed. This bug has been fixed.
938    13. The string returned by pcre_dfa_exec() after a partial match has been
939        changed so that it starts at the first inspected character rather than the
940        first character of the match. This makes a difference only if the pattern
941        starts with a lookbehind assertion or \b or \B (\K is not supported by
942        pcre_dfa_exec()). It's an incompatible change, but it makes the two
943        matching functions compatible, and I think it's the right thing to do.
945    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
946        so that the demonstration program is easily available in environments where
947        PCRE has not been installed from source.
949    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
950        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
951        library.
953    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
954        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
955        is not the first non-POSIX option to be added. Clearly some people find
956        these options useful.
958    17. If a caller to the POSIX matching function regexec() passes a non-zero
959        value for nmatch with a NULL value for pmatch, the value of
960        nmatch is forced to zero.
962    18. RunGrepTest did not have a test for the availability of the -u option of
963        the diff command, as RunTest does. It now checks in the same way as
964        RunTest, and also checks for the -b option.
966    19. If an odd number of negated classes containing just a single character
967        interposed, within parentheses, between a forward reference to a named
968        subpattern and the definition of the subpattern, compilation crashed with
969        an internal error, complaining that it could not find the referenced
970        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
971        [The bug was that it was starting one character too far in when skipping
972        over the character class, thus treating the ] as data rather than
973        terminating the class. This meant it could skip too much.]
975    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
976        /g option in pcretest when the pattern contains \K, which makes it possible
977        to have an empty string match not at the start, even when the pattern is
978        anchored. Updated pcretest and pcredemo to use this option.
980    21. If the maximum number of capturing subpatterns in a recursion was greater
981        than the maximum at the outer level, the higher number was returned, but
982        with unset values at the outer level. The correct (outer level) value is
983        now given.
985    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
986        PCRE did not set those parentheses (unlike Perl). I have now found a way to
987        make it do so. The string so far is captured, making this feature
988        compatible with Perl.
990    23. The tests have been re-organized, adding tests 11 and 12, to make it
991        possible to check the Perl 5.10 features against Perl 5.10.
993    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
994        pattern matches a fixed length string. PCRE did not allow this; now it
995        does. Neither allows recursion.
997    25. I finally figured out how to implement a request to provide the minimum
998        length of subject string that was needed in order to match a given pattern.
999        (It was back references and recursion that I had previously got hung up
1000        on.) This code has now been added to pcre_study(); it finds a lower bound
1001        to the length of subject needed. It is not necessarily the greatest lower
1002        bound, but using it to avoid searching strings that are too short does give
1003        some useful speed-ups. The value is available to calling programs via
1004        pcre_fullinfo().
1006    26. While implementing 25, I discovered to my embarrassment that pcretest had
1007        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1008        study optimizations had never been tested with that matching function.
1009        Oops. What is worse, even when it was passed study data, there was a bug in
1010        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1011        were also very few tests of studied patterns with pcre_dfa_exec().
1013    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1014        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1015        on the other side of the coin, they are no longer allowed to have different
1016        names, because these cannot be distinguished in PCRE, and this has caused
1017        confusion. (This is a difference from Perl.)
1019    28. When duplicate subpattern names are present (necessarily with different
1020        numbers, as required by 27 above), and a test is made by name in a
1021        conditional pattern, either for a subpattern having been matched, or for
1022        recursion in such a pattern, all the associated numbered subpatterns are
1023        tested, and the overall condition is true if the condition is true for any
1024        one of them. This is the way Perl works, and is also more like the way
1025        testing by number works.
1028    Version 7.9 11-Apr-09
1029    ---------------------
1031    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1032        (pcretest), all targets were linked against these libraries. This included
1033        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1034        libraries. This caused unwanted dependencies to be created. This problem
1035        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1036        pcretest is linked with readline.
1038    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1039        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1040        moved outside it again, because FALSE and TRUE are already defined in AIX,
1041        but BOOL is not.
1043    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1044        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1046    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1047        hyphens) following file names and line numbers when outputting matching
1048        lines. This is not true; no spaces are inserted. I have also clarified the
1049        wording for the --colour (or --color) option.
1051    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1052        was not coloured; this is different to GNU grep, so I have changed it to be
1053        the same.
1055    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1056        each matching line was coloured. Now it goes on to look for further matches
1057        of any of the test patterns, which is the same behaviour as GNU grep.
1059    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1060        doesn't make sense to accept an empty string match in pcregrep, so I have
1061        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1062        seems to be how GNU grep behaves.
1064    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1065        start or after a newline", because the conditional assertion was not being
1066        correctly handled. The rule now is that both the assertion and what follows
1067        in the first alternative must satisfy the test.
1069    9.  If auto-callout was enabled in a pattern with a conditional group whose
1070        condition was an assertion, PCRE could crash during matching, both with
1071        pcre_exec() and pcre_dfa_exec().
1073    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1074        used for matching.
1076    11. Unicode property support in character classes was not working for
1077        characters (bytes) greater than 127 when not in UTF-8 mode.
1079    12. Added the -M command line option to pcretest.
1081    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1083    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1085    16. Added comments and documentation about mis-use of no_arg in the C++
1086        wrapper.
1088    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1089        from Martin Jerabek that uses macro names for all relevant character and
1090        string constants.
1092    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1093        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1094        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1095        these, but not everybody uses configure.
1097    19. A conditional group that had only one branch was not being correctly
1098        recognized as an item that could match an empty string. This meant that an
1099        enclosing group might also not be so recognized, causing infinite looping
1100        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1101        with the subject "ab", where knowledge that the repeated group can match
1102        nothing is needed in order to break the loop.
1104    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1105        exec(), but without supplying a callout function, matching went wrong.
1107    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1108        leak if the size of the offset vector was greater than 30. When the vector
1109        is smaller, the saved offsets during recursion go onto a local stack
1110        vector, but for larger vectors malloc() is used. It was failing to free
1111        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1112        error, in fact).
1114    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1115        heapframe that is used only when UTF-8 support is enabled. This caused no
1116        problem, but was untidy.
1118    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1119        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1120        included within another project.
1122    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1123        slightly modified by me:
1125          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1126              not building pcregrep.
1128          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1129              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1131    25. Forward references, both numeric and by name, in patterns that made use of
1132        duplicate group numbers, could behave incorrectly or give incorrect errors,
1133        because when scanning forward to find the reference group, PCRE was not
1134        taking into account the duplicate group numbers. A pattern such as
1135        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1137    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1138        the feature of a custom pointer more persuasive (as requested by a user).
1140    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1141        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1142        pre-defined.
1144    28. Added support for (*UTF8) at the start of a pattern.
1146    29. Arrange for flags added by the "release type" setting in CMake to be shown
1147        in the configuration summary.
1150    Version 7.8 05-Sep-08
1151    ---------------------
1153    1.  Replaced UCP searching code with optimized version as implemented for Ad
1154        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1155        stage table and inline lookup instead of a function, giving speed ups of 2
1156        to 5 times on some simple patterns that I tested. Permission was given to
1157        distribute the MultiStage2.py script that generates the tables (it's not in
1158        the tarball, but is in the Subversion repository).
1160    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1161        scripts.
1163    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1164        a group with a zero qualifier. The result of the study could be incorrect,
1165        or the function might crash, depending on the pattern.
1167    4.  Caseless matching was not working for non-ASCII characters in back
1168        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1169        It now works when Unicode Property Support is available.
1171    5.  In pcretest, an escape such as \x{de} in the data was always generating
1172        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1173        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1174        truncation.
1176    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1178    7.  Added two (int) casts to pcregrep when printing the difference of two
1179        pointers, in case they are 64-bit values.
1181    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1182        test 2 if it fails.
1184    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1185        and a #define of that name to empty if it is not externally set. This is to
1186        allow users of MSVC to set it if necessary.
1188    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1189        the convenience functions in the pcre_get.c source file.
1191    11. An option change at the start of a pattern that had top-level alternatives
1192        could cause overwriting and/or a crash. This command provoked a crash in
1193        some environments:
1195          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1197        This potential security problem was recorded as CVE-2008-2371.
1199    12. For a pattern where the match had to start at the beginning or immediately
1200        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1201        pcre_dfa_exec() could read past the end of the passed subject if there was
1202        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1203        pcretest so that it places the subject at the end of its malloc-ed buffer.
1205    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1206        exec() might read past the end of the data buffer in UTF-8 mode.
1208    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1209        the data contained the byte 0x85 as part of a UTF-8 character within its
1210        first line. This applied both to normal and DFA matching.
1212    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1213        /^[^d]*?$/8 failed to match "abc".
1215    16. Added a missing copyright notice to pcrecpp_internal.h.
1217    17. Make it more clear in the documentation that values returned from
1218        pcre_exec() in ovector are byte offsets, not character counts.
1220    18. Tidied a few places to stop certain compilers from issuing warnings.
1222    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1223        supplied by Stefan Weber. I made a further small update for 7.8 because
1224        there is a change of source arrangements: the pcre_searchfuncs.c module is
1225        replaced by pcre_ucd.c.
1228    Version 7.7 07-May-08
1229    ---------------------
1231    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1232        a string to a long long, pretend we don't even have a long long." This is
1233        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1235    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1236        pre-7.6 versions, which defined a global no_arg variable instead of putting
1237        it in the RE class. (See also #8 below.)
1239    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1240        Lopes.
1242    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1244        (1) The include/exclude patterns were being applied to the whole pathnames
1245            of files, instead of just to the final components.
1247        (2) If there was more than one level of directory, the subdirectories were
1248            skipped unless they satisfied the include/exclude conditions. This is
1249            inconsistent with GNU grep (and could even be seen as contrary to the
1250            pcregrep specification - which I improved to make it absolutely clear).
1251            The action now is always to scan all levels of directory, and just
1252            apply the include/exclude patterns to regular files.
1254    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1255        --exclude_dir in the tests to avoid scanning .svn directories.
1257    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1258        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1259        doesn't support NULs in patterns.
1261    7.  Added some missing "const"s to declarations of static tables in
1262        pcre_compile.c and pcre_dfa_exec.c.
1264    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1265        caused by fix #2  above. (Subsequently also a second patch to fix the
1266        first patch. And a third patch - this was a messy problem.)
1268    9.  Applied Craig's patch to remove the use of push_back().
1270    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1271        matching function regexec().
1273    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1274        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1275        references. PCRE supports relative numbers with this syntax (I don't think
1276        Oniguruma does).
1278    12. Previously, a group with a zero repeat such as (...){0} was completely
1279        omitted from the compiled regex. However, this means that if the group
1280        was called as a subroutine from elsewhere in the pattern, things went wrong
1281        (an internal error was given). Such groups are now left in the compiled
1282        pattern, with a new opcode that causes them to be skipped at execution
1283        time.
1285    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1286        to the way PCRE behaves:
1288        (a) A lone ] character is dis-allowed (Perl treats it as data).
1290        (b) A back reference to an unmatched subpattern matches an empty string
1291            (Perl fails the current match path).
1293        (c) A data ] in a character class must be notated as \] because if the
1294            first data character in a class is ], it defines an empty class. (In
1295            Perl it is not possible to have an empty class.) The empty class []
1296            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1297            The negative empty class [^] matches any one character, independently
1298            of the DOTALL setting.
1300    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1301        non-existent subpattern following a character class starting with ']' and
1302        containing () gave an internal compiling error instead of "reference to
1303        non-existent subpattern". Fortunately, when the pattern did exist, the
1304        compiled code was correct. (When scanning forwards to check for the
1305        existencd of the subpattern, it was treating the data ']' as terminating
1306        the class, so got the count wrong. When actually compiling, the reference
1307        was subsequently set up correctly.)
1309    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1310        it was being rejected as not supported by pcre_dfa_exec(), even though
1311        other assertions are supported. I have made pcre_dfa_exec() support
1312        (*FAIL).
1314    16. The implementation of 13c above involved the invention of a new opcode,
1315        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1316        cannot be changed at match time, I realized I could make a small
1317        improvement to matching performance by compiling OP_ALLANY instead of
1318        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1319        on the OP_ANY path.
1321    17. Compiling pcretest on Windows with readline support failed without the
1322        following two fixes: (1) Make the unistd.h include conditional on
1323        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1325    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1326        ncurses library to be included for pcretest when ReadLine support is
1327        requested, but also to allow for it to be overridden. This patch came from
1328        Daniel Bergström.
1330    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1331        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1332        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1333        spotting this.
1336    Version 7.6 28-Jan-08
1337    ---------------------
1339    1.  A character class containing a very large number of characters with
1340        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1341        overflow.
1343    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1344        HAVE_LONG_LONG is not defined.
1346    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1347        bring them up to date and include new features. This patch includes:
1349        - Fixed PH's badly added libz and libbz2 support.
1350        - Fixed a problem with static linking.
1351        - Added pcredemo. [But later removed - see 7 below.]
1352        - Fixed dftables problem and added an option.
1353        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1354            HAVE_LONG_LONG.
1355        - Added readline support for pcretest.
1356        - Added an listing of the option settings after cmake has run.
1358    4.  A user submitted a patch to Makefile that makes it easy to create
1359        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1360        Makefile.am that cause it to include this special target, without
1361        affecting anything else. Note that the same mingw target plus all
1362        the other distribution libraries and programs are now supported
1363        when configuring with CMake (see 6 below) instead of with
1364        Configure/Make.
1366    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1367        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1368        exported in the Windows port". It has not yet been confirmed that the patch
1369        solves the problem, but it does no harm.
1371    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1372        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1373        with CMake, and also correct the comment about stack recursion.
1375    7.  Remove the automatic building of pcredemo from the ./configure system and
1376        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1377        of a program that users should build themselves after PCRE is installed, so
1378        building it automatically is not really right. What is more, it gave
1379        trouble in some build environments.
1381    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1384    Version 7.5 10-Jan-08
1385    ---------------------
1387    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1388        values in parens when parsing an RE using the C++ wrapper."
1390    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1391        Characters greater than 255 were excluded from the class instead of being
1392        included.
1394    3.  The same bug as (2) above applied to negated POSIX classes such as
1395        [:^space:].
1397    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1398        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1399        I have changed it.
1401    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1402        first named subpattern) and a construct such as (?&a) would reference the
1403        first named subpattern whose name started with "a" (in other words, the
1404        length check was missing). Both these problems are fixed. "Subpattern name
1405        expected" is now given for (?&) (a zero-length name), and this patch also
1406        makes it give the same error for \k'' (previously it complained that that
1407        was a reference to a non-existent subpattern).
1409    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1410        this is right because (?- can be followed by option settings as well as by
1411        digits. I have, however, made the messages clearer.
1413    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1414        than the number used in the conditional) now cause a compile-time error.
1415        This is actually not compatible with Perl, which accepts such patterns, but
1416        treats the conditional as always being FALSE (as PCRE used to), but it
1417        seems to me that giving a diagnostic is better.
1419    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1420        and messages.
1422    9.  Fix two occurrences of "backslash" in comments that should have been
1423        "backspace".
1425    10. Remove two redundant lines of code that can never be obeyed (their function
1426        was moved elsewhere).
1428    11. The program that makes PCRE's Unicode character property table had a bug
1429        which caused it to generate incorrect table entries for sequences of
1430        characters that have the same character type, but are in different scripts.
1431        It amalgamated them into a single range, with the script of the first of
1432        them. In other words, some characters were in the wrong script. There were
1433        thirteen such cases, affecting characters in the following ranges:
1435          U+002b0 - U+002c1
1436          U+0060c - U+0060d
1437          U+0061e - U+00612
1438          U+0064b - U+0065e
1439          U+0074d - U+0076d
1440          U+01800 - U+01805
1441          U+01d00 - U+01d77
1442          U+01d9b - U+01dbf
1443          U+0200b - U+0200f
1444          U+030fc - U+030fe
1445          U+03260 - U+0327f
1446          U+0fb46 - U+0fbb1
1447          U+10450 - U+1049d
1449    12. The -o option (show only the matching part of a line) for pcregrep was not
1450        compatible with GNU grep in that, if there was more than one match in a
1451        line, it showed only the first of them. It now behaves in the same way as
1452        GNU grep.
1454    13. If the -o and -v options were combined for pcregrep, it printed a blank
1455        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1456        does the same. The return code can be used to tell if there were any
1457        non-matching lines.
1459    14. Added --file-offsets and --line-offsets to pcregrep.
1461    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1462        infinitely looping recursion. The bug was that positive lookaheads were not
1463        being skipped when checking for a possible empty match (negative lookaheads
1464        and both kinds of lookbehind were skipped).
1466    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1467        inclusion of <windows.h> to before rather than after the definition of
1468        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1470    17. Specifying a possessive quantifier with a specific limit for a Unicode
1471        character property caused pcre_compile() to compile bad code, which led at
1472        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1473        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1474        caused the error; without that there was no problem.
1476    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1478    19. Added --enable-pcretest-libreadline.
1480    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1481        RE::GlobalReplace(). As a result, the number of replacements returned was
1482        double what it should be. I removed one of the increments, but Craig sent a
1483        later patch that removed the other one (the right fix) and added unit tests
1484        that check the return values (which was not done before).
1486    21. Several CMake things:
1488        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1489            the names libpcre and libpcreposix, not just pcre and pcreposix.
1491        (2) The above change means that pcretest and pcregrep are now correctly
1492            linked with the newly-built libraries, not previously installed ones.
1496    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1497        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1498        UTF-8 newline character). The key issue is that the pattern starts .*;
1499        this means that the match must be either at the beginning, or after a
1500        newline. The bug was in the code for advancing after a failed match and
1501        checking that the new position followed a newline. It was not taking
1502        account of UTF-8 characters correctly.
1504    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1505        character classes. PCRE was not treating the sequence [:...:] as a
1506        character class unless the ... were all letters. Perl, however, seems to
1507        allow any characters between [: and :], though of course it rejects as
1508        unknown any "names" that contain non-letters, because all the known class
1509        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1510        for example, whereas PCRE did not - it did not recognize a POSIX character
1511        class. This seemed a bit dangerous, so the code has been changed to be
1512        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1513        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1514        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1515        Perl does, and where it didn't before.
1517    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1518        Windows environments %n is disabled by default.
1521    Version 7.4 21-Sep-07
1522    ---------------------
1524    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1525        means that a class such as [\s] counted as "explicit reference to CR or
1526        LF". That isn't really right - the whole point of the change was to try to
1527        help when there was an actual mention of one of the two characters. So now
1528        the change happens only if \r or \n (or a literal CR or LF) character is
1529        encountered.
1531    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1532        of both had grown to the point where there were only 3 bits left.
1533        Fortunately, there was spare space in the data structure, and so I have
1534        moved the internal flags into a new 16-bit field to free up more option
1535        bits.
1537    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1538        but did not set the internal JCHANGED flag - either of these is enough to
1539        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1540        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1541        start sets both bits.
1543    4.  Added options (at build time, compile time, exec time) to change \R from
1544        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1546    5.  doc/pcresyntax.html was missing from the distribution.
1548    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1549        compatibility, even though it is no longer used.
1551    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1552        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1553        windows.h file is present (where different names are used). [This was
1554        reversed later after testing - see 16 below.]
1556    8.  Changed all #include <config.h> to #include "config.h". There were also
1557        some further <pcre.h> cases that I changed to "pcre.h".
1559    9.  When pcregrep was used with the --colour option, it missed the line ending
1560        sequence off the lines that it output.
1562    10. It was pointed out to me that arrays of string pointers cause lots of
1563        relocations when a shared library is dynamically loaded. A technique of
1564        using a single long string with a table of offsets can drastically reduce
1565        these. I have refactored PCRE in four places to do this. The result is
1566        dramatic:
1568          Originally:                          290
1569          After changing UCP table:            187
1570          After changing error message table:   43
1571          After changing table of "verbs"       36
1572          After changing table of Posix names   22
1574        Thanks to the folks working on Gregex for glib for this insight.
1576    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1577        unicode-properties was also set.
1579    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1581    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1582        checked only for CRLF.
1584    14. Added casts to pcretest.c to avoid compiler warnings.
1586    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1588    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1589        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1590        entirely. This removes changes made in 7 above.
1592    17. The CMake files have been updated, and there is now more information about
1593        building with CMake in the NON-UNIX-USE document.
1596    Version 7.3 28-Aug-07
1597    ---------------------
1599     1. In the rejigging of the build system that eventually resulted in 7.1, the
1600        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1601        brackets there is not right, since it causes compilers to look for an
1602        installed pcre.h, not the version that is in the source that is being
1603        compiled (which of course may be different). I have changed it back to:
1605          #include "pcre.h"
1607        I have a vague recollection that the change was concerned with compiling in
1608        different directories, but in the new build system, that is taken care of
1609        by the VPATH setting the Makefile.
1611     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1612        when the subject happened to end in the byte 0x85 (e.g. if the last
1613        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1614        characters but of course it shouldn't be taken as a newline when it is part
1615        of another character. The bug was that, for an unlimited repeat of . in
1616        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1617        characters when looking for a newline.
1619     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1621     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1622        in debug output.
1624     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1625        long printing in the pcrecpp unittest when running under MinGW.
1627     6. ESC_K was left out of the EBCDIC table.
1629     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1630        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1631        limit also applies to "virtual nesting" when a pattern is recursive, and in
1632        this case 1000 isn't so big. I have been able to remove this limit at the
1633        expense of backing off one optimization in certain circumstances. Normally,
1634        when pcre_exec() would call its internal match() function recursively and
1635        immediately return the result unconditionally, it uses a "tail recursion"
1636        feature to save stack. However, when a subpattern that can match an empty
1637        string has an unlimited repetition quantifier, it no longer makes this
1638        optimization. That gives it a stack frame in which to save the data for
1639        checking that an empty string has been matched. Previously this was taken
1640        from the 1000-entry workspace that had been reserved. So now there is no
1641        explicit limit, but more stack is used.
1643     8. Applied Daniel's patches to solve problems with the import/export magic
1644        syntax that is required for Windows, and which was going wrong for the
1645        pcreposix and pcrecpp parts of the library. These were overlooked when this
1646        problem was solved for the main library.
1648     9. There were some crude static tests to avoid integer overflow when computing
1649        the size of patterns that contain repeated groups with explicit upper
1650        limits. As the maximum quantifier is 65535, the maximum group length was
1651        set at 30,000 so that the product of these two numbers did not overflow a
1652        32-bit integer. However, it turns out that people want to use groups that
1653        are longer than 30,000 bytes (though not repeat them that many times).
1654        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1655        made it possible to implement the integer overflow checks in a much more
1656        dynamic way, which I have now done. The artificial limitation on group
1657        length has been removed - we now have only the limit on the total length of
1658        the compiled pattern, which depends on the LINK_SIZE setting.
1660    10. Fixed a bug in the documentation for get/copy named substring when
1661        duplicate names are permitted. If none of the named substrings are set, the
1662        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1663        empty string.
1665    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1666        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1667        because the ] is interpreted as the first data character and the
1668        terminating ] is not found. PCRE has been made compatible with Perl in this
1669        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1670        cause memory overwriting.
1672    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1673        string has been matched (to stop an infinite loop). It was not recognizing
1674        a conditional subpattern that could match an empty string if that
1675        subpattern was within another subpattern. For example, it looped when
1676        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1677        condition was not nested. This bug has been fixed.
1679    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1680        past the start of the subject in the presence of bytes with the top bit
1681        set, for example "\x8aBCD".
1683    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1684        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1686    14. Optimized (?!) to (*FAIL).
1688    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1689        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1690        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1691        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1692        does: it's just the validity check that is more restrictive.
1694    16. Inserted checks for integer overflows during escape sequence (backslash)
1695        processing, and also fixed erroneous offset values for syntax errors during
1696        backslash processing.
1698    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1699        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1701    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1702        caused an overrun.
1704    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1705        something other than just ASCII characters) inside a group that had an
1706        unlimited repeat caused a loop at compile time (while checking to see
1707        whether the group could match an empty string).
1709    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1710        [\P{Any}] did so. (Error in the code for printing property names.)
1712    21. An orphan \E inside a character class could cause a crash.
1714    22. A repeated capturing bracket such as (A)? could cause a wild memory
1715        reference during compilation.
1717    23. There are several functions in pcre_compile() that scan along a compiled
1718        expression for various reasons (e.g. to see if it's fixed length for look
1719        behind). There were bugs in these functions when a repeated \p or \P was
1720        present in the pattern. These operators have additional parameters compared
1721        with \d, etc, and these were not being taken into account when moving along
1722        the compiled data. Specifically:
1724        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1725            length.
1727        (b) An item such as \pL+ within a repeated group could cause crashes or
1728            loops.
1730        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1731            "reference to non-existent subpattern" error.
1733        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1735    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1736        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1738    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1740    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1741        character were causing crashes (broken optimization).
1743    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1744        \p or \P) caused a compile-time loop.
1746    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1747        break. For example, the unstudied pattern [\r\n]A does not match the string
1748        "\r\nA" because change 7.0/46 below moves the current point on by two
1749        characters after failing to match at the start. However, the pattern \nA
1750        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1751        the same is true. There doesn't seem any very clean way out of this, but
1752        what I have chosen to do makes the common cases work: PCRE now takes note
1753        of whether there can be an explicit match for \r or \n anywhere in the
1754        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1755        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1756        pattern has explicit CR or LF references.
1758    29. Added (*CR) etc for changing newline setting at start of pattern.
1761    Version 7.2 19-Jun-07
1762    ---------------------
1764     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1765        which is apparently normally available under Windows.
1767     2. Re-jig the pcregrep tests with different newline settings in an attempt
1768        to make them independent of the local environment's newline setting.
1770     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1772     4. Some of the "internals" tests were previously cut out when the link size
1773        was not 2, because the output contained actual offsets. The recent new
1774        "Z" feature of pcretest means that these can be cut out, making the tests
1775        usable with all link sizes.
1777     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1778        stack recursion. This gives a massive performance boost under BSD, but just
1779        a small improvement under Linux. However, it saves one field in the frame
1780        in all cases.
1782     6. Added more features from the forthcoming Perl 5.10:
1784        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1785            recursion call. It refers to the nth most recently opened parentheses.
1787        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1788            to be opened parentheses.
1790        (c) Conditions that refer to capturing parentheses can be specified
1791            relatively, for example, (?(-2)... or (?(+3)...
1793        (d) \K resets the start of the current match so that everything before
1794            is not part of it.
1796        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1798        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1799            reference syntax.
1801        (g) (?| introduces a group in which the numbering of parentheses in each
1802            alternative starts with the same number.
1804        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1806     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1809     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1810        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1811        for detecting groups that can match an empty string.
1813     9. A pattern with a very large number of alternatives (more than several
1814        hundred) was running out of internal workspace during the pre-compile
1815        phase, where pcre_compile() figures out how much memory will be needed. A
1816        bit of new cunning has reduced the workspace needed for groups with
1817        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1818        workspace instead of running out of the 4096 that are available.
1820    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1822    11. Applied patch from Google to remove an optimization that didn't quite work.
1823        The report of the bug said:
1825          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1826          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1827          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1829    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1830        it matched the wrong number of bytes.
1833    Version 7.1 24-Apr-07
1834  ---------------------  ---------------------
1836   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
# Line 136  Version 7.1 12-Mar-07 Line 1965  Version 7.1 12-Mar-07
1965      string at the end of a line did not allow for this case. They now check for      string at the end of a line did not allow for this case. They now check for
1966      it specially.      it specially.
1968    20. pcretest is supposed to handle patterns and data of any length, by
1969        extending its buffers when necessary. It was getting this wrong when the
1970        buffer for a data line had to be extended.
1972    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1973        CRLF as a newline sequence.
1975    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1976        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1977        I have nevertheless tidied it up.
1979    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1981    24. Added a man page for pcre-config.
1984  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1985  ---------------------  ---------------------

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