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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.6 21-Jan-08  Version 8.30
5    ------------
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
10    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
11        only in quite long subpatterns.
13    3.  Removed the function pcre_info(), which has been obsolete and deprecated
14        since it was replaced by pcre_fullinfo() in February 2000.
16    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
17        match a (*MARK), and the match failed at the start of the subject, a
18        reference to memory before the start of the subject could occur. This bug
19        was introduced by fix 17 of release 8.21.
21    5.  A reference to an unset group with zero minimum repetition was giving
22        totally wrong answers (in non-JavaScript-compatibility mode). For example,
23        /(another)?(\1?)test/ matched against "hello world test". This bug was
24        introduced in release 8.13.
26    6.  Add support for 16-bit character strings (a large amount of work involving
27        many changes and refactorings).
29    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
30        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
31        from a file.
33    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
34        rounding is not applied in this particular case).
36    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37        if they appear, or are escaped, in patterns.
39    10. Get rid of a number of -Wunused-but-set-variable warnings.
41    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44        also returns the mark "x". This bug applied to capturing parentheses,
45        non-capturing parentheses, and atomic parentheses.
48    Version 8.21 12-Dec-2011
49    ------------------------
51    1.  Updating the JIT compiler.
53    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
54        are added as well.
56    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
57        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
58        calling _pcre_jit_exec. Some extra comments are added.
60    4.  (*MARK) settings inside atomic groups that do not contain any capturing
61        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
62        was introduced by change 18 for 8.20.
64    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
65        ECMA-262 standard.
67    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
68        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
69        This bug was probably introduced by change 9 of 8.13.
71    7.  While fixing 6 above, I noticed that a number of other items were being
72        incorrectly rejected as "not fixed length". This arose partly because newer
73        opcodes had not been added to the fixed-length checking code. I have (a)
74        corrected the bug and added tests for these items, and (b) arranged for an
75        error to occur if an unknown opcode is encountered while checking for fixed
76        length instead of just assuming "not fixed length". The items that were
77        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
78        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
79        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
81    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
82        being incorrectly compiled and would have given unpredicatble results.
84    9.  A possessively repeated subpattern with minimum repeat count greater than
85        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
86        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
87        the first (A) could occur when it should not.
89    10. Add a cast and remove a redundant test from the code.
91    11. JIT should use pcre_malloc/pcre_free for allocation.
93    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
94        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
95        is anything other than /usr, -L is still shown).
97    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
99    14. Perl does not support \N without a following name in a [] class; PCRE now
100        also gives an error.
102    15. If a forward reference was repeated with an upper limit of around 2000,
103        it caused the error "internal error: overran compiling workspace". The
104        maximum number of forward references (including repeats) was limited by the
105        internal workspace, and dependent on the LINK_SIZE. The code has been
106        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
107        the default depends on LINK_SIZE. There is a new upper limit (for safety)
108        of around 200,000 forward references. While doing this, I also speeded up
109        the filling in of repeated forward references.
111    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
112        incorrectly expecting the subject to contain another "a" after the start.
114    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
115        in the match, the SKIP should be ignored. This was not happening; instead
116        the SKIP was being treated as NOMATCH. For patterns such as
117        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
118        tested.
120    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
121        now much more compatible with Perl, in particular in cases where the result
122        is a non-match for a non-anchored pattern. For example, if
123        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
124        "m", where previously it did not return a name. A side effect of this
125        change is that for partial matches, the last encountered mark name is
126        returned, as for non matches. A number of tests that were previously not
127        Perl-compatible have been moved into the Perl-compatible test files. The
128        refactoring has had the pleasing side effect of removing one argument from
129        the match() function, thus reducing its stack requirements.
131    19. If the /S+ option was used in pcretest to study a pattern using JIT,
132        subsequent uses of /S (without +) incorrectly behaved like /S+.
134    21. Retrieve executable code size support for the JIT compiler and fixing
135        some warnings.
137    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
138        not work when the shorter character appeared right at the end of the
139        subject string.
141    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
142        systems.
144    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
145        output it when the /M option is used in pcretest.
147    25. The CheckMan script was not being included in the distribution. Also, added
148        an explicit "perl" to run Perl scripts from the PrepareRelease script
149        because this is reportedly needed in Windows.
151    26. If study data was being save in a file and studying had not found a set of
152        "starts with" bytes for the pattern, the data written to the file (though
153        never used) was taken from uninitialized memory and so caused valgrind to
154        complain.
156    27. Updated RunTest.bat as provided by Sheri Pierce.
158    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
160    29. Computation of memory usage for the table of capturing group names was
161        giving an unnecessarily large value.
164    Version 8.20 21-Oct-2011
165    ------------------------
167    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
168        a POSIX class. After further experiments with Perl, which convinced me that
169        Perl has bugs and confusions, a closing square bracket is no longer allowed
170        in a POSIX name. This bug also affected patterns with classes that started
171        with full stops.
173    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
174        captured substring, but while checking the failing first alternative,
175        substring 1 is temporarily captured. If the output vector supplied to
176        pcre_exec() was not big enough for this capture, the yield of the function
177        was still zero ("insufficient space for captured substrings"). This cannot
178        be totally fixed without adding another stack variable, which seems a lot
179        of expense for a edge case. However, I have improved the situation in cases
180        such as /(a)(b)x|abc/ matched against "abc", where the return code
181        indicates that fewer than the maximum number of slots in the ovector have
182        been set.
184    3.  Related to (2) above: when there are more back references in a pattern than
185        slots in the output vector, pcre_exec() uses temporary memory during
186        matching, and copies in the captures as far as possible afterwards. It was
187        using the entire output vector, but this conflicts with the specification
188        that only 2/3 is used for passing back captured substrings. Now it uses
189        only the first 2/3, for compatibility. This is, of course, another edge
190        case.
192    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
193        main code base, and can be used by building with --enable-jit. When this is
194        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
195        runtime --no-jit option is given.
197    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
198        ovector, the return from the function was zero, implying that there were
199        other matches that did not fit. The correct "exactly full" value is now
200        returned.
202    6.  If a subpattern that was called recursively or as a subroutine contained
203        (*PRUNE) or any other control that caused it to give a non-standard return,
204        invalid errors such as "Error -26 (nested recursion at the same subject
205        position)" or even infinite loops could occur.
207    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
208        computing the minimum length on reaching *ACCEPT, and so ended up with the
209        wrong value of 1 rather than 0. Further investigation indicates that
210        computing a minimum subject length in the presence of *ACCEPT is difficult
211        (think back references, subroutine calls), and so I have changed the code
212        so that no minimum is registered for a pattern that contains *ACCEPT.
214    8.  If (*THEN) was present in the first (true) branch of a conditional group,
215        it was not handled as intended. [But see 16 below.]
217    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
218        Sheri Pierce.
220    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
221        the first byte in a match must be "a".
223    11. Change 17 for 8.13 increased the recursion depth for patterns like
224        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
225        pattern contains any instances of (*THEN). If it does not, the old
226        optimizations are restored. It would be nice to do this on a per-group
227        basis, but at the moment that is not feasible.
229    12. In some environments, the output of pcretest -C is CRLF terminated. This
230        broke RunTest's code that checks for the link size. A single white space
231        character after the value is now allowed for.
233    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
234        For "fr", it uses the Windows-specific input and output files.
236    14. If (*THEN) appeared in a group that was called recursively or as a
237        subroutine, it did not work as intended. [But see next item.]
239    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
240        pattern fragments (but not containing any | characters). If A and B are
241        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
242        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
243        D. In other words, Perl considers parentheses that do not contain any |
244        characters to be part of a surrounding alternative, whereas PCRE was
245        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
246        differently. PCRE now behaves in the same way as Perl, except in the case
247        of subroutine/recursion calls such as (?1) which have in any case always
248        been different (but PCRE had them first :-).
250    16. Related to 15 above: Perl does not treat the | in a conditional group as
251        creating alternatives. Such a group is treated in the same way as an
252        ordinary group without any | characters when processing (*THEN). PCRE has
253        been changed to match Perl's behaviour.
255    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
256        RunGrepTest script failed.
258    18. Change 22 for version 13 caused atomic groups to use more stack. This is
259        inevitable for groups that contain captures, but it can lead to a lot of
260        stack use in large patterns. The old behaviour has been restored for atomic
261        groups that do not contain any capturing parentheses.
263    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
264        suppress the check for a minimum subject length at run time. (If it was
265        given to pcre_exec() or pcre_dfa_exec() it did work.)
267    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
268        fail to work when decoding hex characters in data strings in EBCDIC
269        environments.
271    21. It appears that in at least one Mac OS environment, the isxdigit() function
272        is implemented as a macro that evaluates to its argument more than once,
273        contravening the C 90 Standard (I haven't checked a later standard). There
274        was an instance in pcretest which caused it to go wrong when processing
275        \x{...} escapes in subject strings. The has been rewritten to avoid using
276        things like p++ in the argument of isxdigit().
279    Version 8.13 16-Aug-2011
280    ------------------------
282    1.  The Unicode data tables have been updated to Unicode 6.0.0.
284    2.  Two minor typos in pcre_internal.h have been fixed.
286    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
287        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
288        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
290    4.  There were a number of related bugs in the code for matching backrefences
291        caselessly in UTF-8 mode when codes for the characters concerned were
292        different numbers of bytes. For example, U+023A and U+2C65 are an upper
293        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
294        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
295        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
296        2-byte code at the end of the subject (it thought there wasn't enough data
297        left).
299    5.  Comprehensive information about what went wrong is now returned by
300        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
301        as the output vector has at least 2 elements. The offset of the start of
302        the failing character and a reason code are placed in the vector.
304    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
305        now returned is for the first byte of the failing character, instead of the
306        last byte inspected. This is an incompatible change, but I hope it is small
307        enough not to be a problem. It makes the returned offset consistent with
308        pcre_exec() and pcre_dfa_exec().
310    7.  pcretest now gives a text phrase as well as the error number when
311        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
312        failure, the offset and reason code are output.
314    8.  When \R was used with a maximizing quantifier it failed to skip backwards
315        over a \r\n pair if the subsequent match failed. Instead, it just skipped
316        back over a single character (\n). This seems wrong (because it treated the
317        two characters as a single entity when going forwards), conflicts with the
318        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
319        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
320        has been changed.
322    9.  Some internal refactoring has changed the processing so that the handling
323        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
324        time (the PCRE_DOTALL option was changed this way some time ago: version
325        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
326        which was always a bit of a fudge. It also means that there is one less
327        argument for the match() function, which reduces its stack requirements
328        slightly. This change also fixes an incompatibility with Perl: the pattern
329        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
331    10. More internal refactoring has drastically reduced the number of recursive
332        calls to match() for possessively repeated groups such as (abc)++ when
333        using pcre_exec().
335    11. While implementing 10, a number of bugs in the handling of groups were
336        discovered and fixed:
338        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
339        (a|)*(?1) gave a compile-time internal error.
340        ((a|)+)+  did not notice that the outer group could match an empty string.
341        (^a|^)+   was not marked as anchored.
342        (.*a|.*)+ was not marked as matching at start or after a newline.
344    12. Yet more internal refactoring has removed another argument from the match()
345        function. Special calls to this function are now indicated by setting a
346        value in a variable in the "match data" data block.
348    13. Be more explicit in pcre_study() instead of relying on "default" for
349        opcodes that mean there is no starting character; this means that when new
350        ones are added and accidentally left out of pcre_study(), testing should
351        pick them up.
353    14. The -s option of pcretest has been documented for ages as being an old
354        synonym of -m (show memory usage). I have changed it to mean "force study
355        for every regex", that is, assume /S for every regex. This is similar to -i
356        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
357        using it. It makes it easier to run collections of tests with and without
358        study enabled, and thereby test pcre_study() more easily. All the standard
359        tests are now run with and without -s (but some patterns can be marked as
360        "never study" - see 20 below).
362    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
363        restoration of the capturing data to the outer values was not happening
364        correctly.
366    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
367        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
368        pattern had matched an empty string, and so incorrectly returned a no
369        match.
371    17. There was optimizing code for the last branch of non-capturing parentheses,
372        and also for the obeyed branch of a conditional subexpression, which used
373        tail recursion to cut down on stack usage. Unfortunately, now that there is
374        the possibility of (*THEN) occurring in these branches, tail recursion is
375        no longer possible because the return has to be checked for (*THEN). These
376        two optimizations have therefore been removed. [But see 8.20/11 above.]
378    18. If a pattern containing \R was studied, it was assumed that \R always
379        matched two bytes, thus causing the minimum subject length to be
380        incorrectly computed because \R can also match just one byte.
382    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
383        was incorrectly computed.
385    20. If /S is present twice on a test pattern in pcretest input, it now
386        *disables* studying, thereby overriding the use of -s on the command line
387        (see 14 above). This is necessary for one or two tests to keep the output
388        identical in both cases.
390    21. When (*ACCEPT) was used in an assertion that matched an empty string and
391        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
393    22. When an atomic group that contained a capturing parenthesis was
394        successfully matched, but the branch in which it appeared failed, the
395        capturing was not being forgotten if a higher numbered group was later
396        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
397        group 1 to "a", when in fact it should be unset. This applied to multi-
398        branched capturing and non-capturing groups, repeated or not, and also to
399        positive assertions (capturing in negative assertions does not happen
400        in PCRE) and also to nested atomic groups.
402    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
403        subject after a captured substring, to make it easier to tell which of a
404        number of identical substrings has been captured.
406    24. The way atomic groups are processed by pcre_exec() has been changed so that
407        if they are repeated, backtracking one repetition now resets captured
408        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
409        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
410        "aaa". Previously, it would have been "a". As part of this code
411        refactoring, the way recursive calls are handled has also been changed.
413    25. If an assertion condition captured any substrings, they were not passed
414        back unless some other capturing happened later. For example, if
415        (?(?=(a))a) was matched against "a", no capturing was returned.
417    26. When studying a pattern that contained subroutine calls or assertions,
418        the code for finding the minimum length of a possible match was handling
419        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
420        group 1 called group 2 while simultaneously a separate group 2 called group
421        1). A stack overflow occurred in this case. I have fixed this by limiting
422        the recursion depth to 10.
424    27. Updated RunTest.bat in the distribution to the version supplied by Tom
425        Fortmann. This supports explicit test numbers on the command line, and has
426        argument validation and error reporting.
428    28. An instance of \X with an unlimited repeat could fail if at any point the
429        first character it looked at was a mark character.
431    29. Some minor code refactoring concerning Unicode properties and scripts
432        should reduce the stack requirement of match() slightly.
434    30. Added the '=' option to pcretest to check the setting of unused capturing
435        slots at the end of the pattern, which are documented as being -1, but are
436        not included in the return count.
438    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
439        compiled something random. Now it gives a compile-time error (as does
440        Perl).
442    32. A *MARK encountered during the processing of a positive assertion is now
443        recorded and passed back (compatible with Perl).
445    33. If --only-matching or --colour was set on a pcregrep call whose pattern
446        had alternative anchored branches, the search for a second match in a line
447        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
448        matched the line "0102" twice. The same bug affected patterns that started
449        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
450        twice.
452    34. Previously, PCRE did not allow quantification of assertions. However, Perl
453        does, and because of capturing effects, quantifying parenthesized
454        assertions may at times be useful. Quantifiers are now allowed for
455        parenthesized assertions.
457    35. A minor code tidy in pcre_compile() when checking options for \R usage.
459    36. \g was being checked for fancy things in a character class, when it should
460        just be a literal "g".
462    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
463        appearance of a nested POSIX class supersedes an apparent external class.
464        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
465        unescaped square brackets may also appear as part of class names. For
466        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
467        more like Perl. (But see 8.20/1 above.)
469    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
470        was because it thought it was \N{name}, which is not supported).
472    39. Add minix to OS list not supporting the -S option in pcretest.
474    40. PCRE tries to detect cases of infinite recursion at compile time, but it
475        cannot analyze patterns in sufficient detail to catch mutual recursions
476        such as ((?1))((?2)). There is now a runtime test that gives an error if a
477        subgroup is called recursively as a subpattern for a second time at the
478        same position in the subject string. In previous releases this might have
479        been caught by the recursion limit, or it might have run out of stack.
481    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
482        happen only once. PCRE was, however incorrectly giving a compile time error
483        "recursive call could loop indefinitely" because it cannot analyze the
484        pattern in sufficient detail. The compile time test no longer happens when
485        PCRE is compiling a conditional subpattern, but actual runaway loops are
486        now caught at runtime (see 40 above).
488    42. It seems that Perl allows any characters other than a closing parenthesis
489        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
490        has been changed to be the same.
492    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
493        as not to get warnings when autogen.sh is called. Also changed
494        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
496    44. To help people who use pcregrep to scan files containing exceedingly long
497        lines, the following changes have been made:
499        (a) The default value of the buffer size parameter has been increased from
500            8K to 20K. (The actual buffer used is three times this size.)
502        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
503            PCRE is built.
505        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
506            to be set at run time.
508        (d) Numerical values in pcregrep options can be followed by K or M, for
509            example --buffer-size=50K.
511        (e) If a line being scanned overflows pcregrep's buffer, an error is now
512            given and the return code is set to 2.
514    45. Add a pointer to the latest mark to the callout data block.
516    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
517        partial match of an empty string instead of no match. This was specific to
518        the use of ".".
520    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
521        complete match instead of a partial match. This bug was dependent on both
522        the PCRE_UTF8 and PCRE_DOTALL options being set.
524    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
525        starting byte set, because \b was not being ignored.
528    Version 8.12 15-Jan-2011
529    ------------------------
531    1.  Fixed some typos in the markup of the man pages, and wrote a script that
532        checks for such things as part of the documentation building process.
534    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
535        --match-limit and --recursion-limit options (added for 8.11). In
536        particular, this made one of the standard tests fail. (The integer value
537        went into the wrong half of a long int.)
539    3.  If the --colour option was given to pcregrep with -v (invert match), it
540        did strange things, either producing crazy output, or crashing. It should,
541        of course, ignore a request for colour when reporting lines that do not
542        match.
544    4.  Another pcregrep bug caused similar problems if --colour was specified with
545        -M (multiline) and the pattern match finished with a line ending.
547    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
548        matched in multiline mode, the following line was shown as part of the
549        match. This seems wrong, so I have changed it.
551    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
552        the check for further matches in the same line (so they could be coloured)
553        to overrun the end of the current line. If another match was found, it was
554        incorrectly shown (and then shown again when found in the next line).
556    7.  If pcregrep was compiled under Windows, there was a reference to the
557        function pcregrep_exit() before it was defined. I am assuming this was
558        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
559        reported by a user. I've moved the definition above the reference.
562    Version 8.11 10-Dec-2010
563    ------------------------
565    1.  (*THEN) was not working properly if there were untried alternatives prior
566        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
567        backtracked to try for "b" instead of moving to the next alternative branch
568        at the same level (in this case, to look for "c"). The Perl documentation
569        is clear that when (*THEN) is backtracked onto, it goes to the "next
570        alternative in the innermost enclosing group".
572    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
573        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
574        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
575        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
576        (*THEN).
578    3.  If \s appeared in a character class, it removed the VT character from
579        the class, even if it had been included by some previous item, for example
580        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
581        of \s, but is part of the POSIX "space" class.)
583    4.  A partial match never returns an empty string (because you can always
584        match an empty string at the end of the subject); however the checking for
585        an empty string was starting at the "start of match" point. This has been
586        changed to the "earliest inspected character" point, because the returned
587        data for a partial match starts at this character. This means that, for
588        example, /(?<=abc)def/ gives a partial match for the subject "abc"
589        (previously it gave "no match").
591    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
592        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
593        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
594        has an implication that the given string is incomplete (because a partial
595        match is preferred over a full match). For this reason, these items now
596        give a partial match in this situation. [Aside: previously, the one case
597        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
598        match rather than a full match, which was wrong by the old rules, but is
599        now correct.]
601    6.  There was a bug in the handling of #-introduced comments, recognized when
602        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
603        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
604        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
605        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
606        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
607        places in pcre_compile().
609    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
610        comments when looking ahead for named forward references to subpatterns,
611        the only newline sequence it recognized was NL. It now handles newlines
612        according to the set newline convention.
614    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
615        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
616        cater for a lack of strerror(). These oversights have been fixed.
618    9.  Added --match-limit and --recursion-limit to pcregrep.
620    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
622    11. When the -o option was used, pcregrep was setting a return code of 1, even
623        when matches were found, and --line-buffered was not being honoured.
625    12. Added an optional parentheses number to the -o and --only-matching options
626        of pcregrep.
628    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
629        can match an empty string. The code to do it in pcretest and pcredemo
630        needed fixing:
632        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
633            only one byte after an empty string match just before CRLF (this case
634            just got forgotten; "any" and "anycrlf" were OK).
636        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
637            mode when an empty string match preceded an ASCII character followed by
638            a non-ASCII character. (The code for advancing by one character rather
639            than one byte was nonsense.)
641        (c) The pcredemo.c sample program did not have any code at all to handle
642            the cases when CRLF is a valid newline sequence.
644    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
645        as a starting offset was within the subject string. There is now a new
646        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
647        negative or greater than the length of the string. In order to test this,
648        pcretest is extended to allow the setting of negative starting offsets.
650    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
651        starting offset points to the beginning of a UTF-8 character was
652        unnecessarily clumsy. I tidied it up.
654    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
655        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
657    17. Nobody had reported that the --include_dir option, which was added in
658        release 7.7 should have been called --include-dir (hyphen, not underscore)
659        for compatibility with GNU grep. I have changed it to --include-dir, but
660        left --include_dir as an undocumented synonym, and the same for
661        --exclude-dir, though that is not available in GNU grep, at least as of
662        release 2.5.4.
664    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
665        characters from a string of bytes) have been redefined so as not to use
666        loops, in order to improve performance in some environments. At the same
667        time, I abstracted some of the common code into auxiliary macros to save
668        repetition (this should not affect the compiled code).
670    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
671        compile-time error is now given if \c is not followed by an ASCII
672        character, that is, a byte less than 128. (In EBCDIC mode, the code is
673        different, and any byte value is allowed.)
675    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
676        START_OPTIMIZE option, which is now allowed at compile time - but just
677        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
678        to pcregrep and other applications that have no direct access to PCRE
679        options. The new /Y option in pcretest sets this option when calling
680        pcre_compile().
682    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
683        back references. Groups containing recursive back references were forced to
684        be atomic by that change, but in the case of named groups, the amount of
685        memory required was incorrectly computed, leading to "Failed: internal
686        error: code overflow". This has been fixed.
688    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
689        pcretest.c, to avoid build problems in some Borland environments.
692    Version 8.10 25-Jun-2010
693    ------------------------
695    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
696        THEN.
698    2.  (*ACCEPT) was not working when inside an atomic group.
700    3.  Inside a character class, \B is treated as a literal by default, but
701        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
702        causes the error). The code is unchanged, but I tidied the documentation.
704    4.  Inside a character class, PCRE always treated \R and \X as literals,
705        whereas Perl faults them if its -w option is set. I have changed PCRE so
706        that it faults them when PCRE_EXTRA is set.
708    5.  Added support for \N, which always matches any character other than
709        newline. (It is the same as "." when PCRE_DOTALL is not set.)
711    6.  When compiling pcregrep with newer versions of gcc which may have
712        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
713        declared with attribute warn_unused_result" were given. Just casting the
714        result to (void) does not stop the warnings; a more elaborate fudge is
715        needed. I've used a macro to implement this.
717    7.  Minor change to pcretest.c to avoid a compiler warning.
719    8.  Added four artifical Unicode properties to help with an option to make
720        \s etc use properties (see next item). The new properties are: Xan
721        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
723    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
724        use Unicode properties. (*UCP) at the start of a pattern can be used to set
725        this option. Modified pcretest to add /W to test this facility. Added
726        REG_UCP to make it available via the POSIX interface.
728    10. Added --line-buffered to pcregrep.
730    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
731        studied, and the match started with a letter with a code point greater than
732        127 whose first byte was different to the first byte of the other case of
733        the letter, the other case of this starting letter was not recognized
734        (#976).
736    12. If a pattern that was studied started with a repeated Unicode property
737        test, for example, \p{Nd}+, there was the theoretical possibility of
738        setting up an incorrect bitmap of starting bytes, but fortunately it could
739        not have actually happened in practice until change 8 above was made (it
740        added property types that matched character-matching opcodes).
742    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
743        possible starting bytes for non-anchored patterns.
745    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
746        \R, and also a number of cases that involve Unicode properties, both
747        explicit and implicit when PCRE_UCP is set.
749    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
750        input, it could crash or give wrong results if characters with values
751        greater than 0xc0 were present in the subject string. (Detail: it assumed
752        UTF-8 input when processing these items.)
754    16. Added a lot of (int) casts to avoid compiler warnings in systems where
755        size_t is 64-bit (#991).
757    17. Added a check for running out of memory when PCRE is compiled with
758        --disable-stack-for-recursion (#990).
760    18. If the last data line in a file for pcretest does not have a newline on
761        the end, a newline was missing in the output.
763    19. The default pcre_chartables.c file recognizes only ASCII characters (values
764        less than 128) in its various bitmaps. However, there is a facility for
765        generating tables according to the current locale when PCRE is compiled. It
766        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
767        characters, are recognized by isspace() and therefore were getting set in
768        these tables, and indeed these tables seem to approximate to ISO 8859. This
769        caused a problem in UTF-8 mode when pcre_study() was used to create a list
770        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
771        which of course cannot start UTF-8 characters. I have changed the code so
772        that only real ASCII characters (less than 128) and the correct starting
773        bytes for UTF-8 encodings are set for characters greater than 127 when in
774        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
775        altogether.)
777    20. Added the /T option to pcretest so as to be able to run tests with non-
778        standard character tables, thus making it possible to include the tests
779        used for 19 above in the standard set of tests.
781    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
782        reference to a subpattern the other side of a comment that contains an
783        opening parenthesis caused either an internal compiling error, or a
784        reference to the wrong subpattern.
787    Version 8.02 19-Mar-2010
788    ------------------------
790    1.  The Unicode data tables have been updated to Unicode 5.2.0.
792    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
793        configured.
795    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
796        original author of that file, following a query about its status.
798    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
799        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
801    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
802        quantifier applied to a forward-referencing subroutine call, could compile
803        incorrect code or give the error "internal error: previously-checked
804        referenced subpattern not found".
806    6.  Both MS Visual Studio and Symbian OS have problems with initializing
807        variables to point to external functions. For these systems, therefore,
808        pcre_malloc etc. are now initialized to local functions that call the
809        relevant global functions.
811    7.  There were two entries missing in the vectors called coptable and poptable
812        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
813        I've fixed the data, and added a kludgy way of testing at compile time that
814        the lengths are correct (equal to the number of opcodes).
816    8.  Following on from 7, I added a similar kludge to check the length of the
817        eint vector in pcreposix.c.
819    9.  Error texts for pcre_compile() are held as one long string to avoid too
820        much relocation at load time. To find a text, the string is searched,
821        counting zeros. There was no check for running off the end of the string,
822        which could happen if a new error number was added without updating the
823        string.
825    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
827    11. \K was not working if it appeared in an atomic group or in a group that
828        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
829        \K is "not well defined" if used in an assertion. PCRE now accepts it if
830        the assertion is positive, but not if it is negative.
832    12. Change 11 fortuitously reduced the size of the stack frame used in the
833        "match()" function of pcre_exec.c by one pointer. Forthcoming
834        implementation of support for (*MARK) will need an extra pointer on the
835        stack; I have reserved it now, so that the stack frame size does not
836        decrease.
838    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
839        item in branch that calls a recursion is a subroutine call - as in the
840        second branch in the above example - was incorrectly given the compile-
841        time error "recursive call could loop indefinitely" because pcre_compile()
842        was not correctly checking the subroutine for matching a non-empty string.
844    14. The checks for overrunning compiling workspace could trigger after an
845        overrun had occurred. This is a "should never occur" error, but it can be
846        triggered by pathological patterns such as hundreds of nested parentheses.
847        The checks now trigger 100 bytes before the end of the workspace.
849    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
852    Version 8.01 19-Jan-2010
853    ------------------------
855    1.  If a pattern contained a conditional subpattern with only one branch (in
856        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
857        computed the wrong minimum data length (which is of course zero for such
858        subpatterns). This could cause incorrect "no match" results.
860    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
861        the pattern is reset in the first branch, pcre_compile() failed with
862        "internal error: code overflow at offset...". This happened only when
863        the reset was to the original external option setting. (An optimization
864        abstracts leading options settings into an external setting, which was the
865        cause of this.)
867    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
868        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
869        assertion pattern did not match (meaning that the assertion was true), it
870        was incorrectly treated as false if the SKIP had been reached during the
871        matching. This also applied to assertions used as conditions.
873    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
874        assertion subpattern, including such a pattern used as a condition,
875        unpredictable results occurred, instead of the error return
878    5.  The C++ GlobalReplace function was not working like Perl for the special
879        situation when an empty string is matched. It now does the fancy magic
880        stuff that is necessary.
882    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
883        removed. (These were left over from very, very early versions of PCRE.)
885    7.  Some cosmetic changes to the code to make life easier when compiling it
886        as part of something else:
888        (a) Change DEBUG to PCRE_DEBUG.
890        (b) In pcre_compile(), rename the member of the "branch_chain" structure
891            called "current" as "current_branch", to prevent a collision with the
892            Linux macro when compiled as a kernel module.
894        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
895            prevent a collision with the Linux macro when compiled as a kernel
896            module.
898    8.  In pcre_compile() there are some checks for integer overflows that used to
899        cast potentially large values to (double). This has been changed to that
900        when building, a check for int64_t is made, and if it is found, it is used
901        instead, thus avoiding the use of floating point arithmetic. (There is no
902        other use of FP in PCRE.) If int64_t is not found, the fallback is to
903        double.
905    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
906        2005 (difference between two addresses compared to an unsigned value).
908    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
909        custom one, because of the following reported problem in Windows:
911          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
912              under Win32.
913          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
914              therefore missing the function definition.
915          - The compiler thus generates a "C" signature for the test function.
916          - The linker fails to find the "C" function.
917          - PCRE fails to configure if asked to do so against libbz2.
919    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
920        messages were output:
922          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
923          rerunning libtoolize, to keep the correct libtool macros in-tree.
924          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
926        I have done both of these things.
928    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
929        most of the time, it *can* run out if it is given a pattern that contains a
930        runaway infinite recursion. I updated the discussion in the pcrestack man
931        page.
933    13. Now that we have gone to the x.xx style of version numbers, the minor
934        version may start with zero. Using 08 or 09 is a bad idea because users
935        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
936        interpreted as invalid octal numbers. I've updated the previous comment in
937        configure.ac, and also added a check that gives an error if 08 or 09 are
938        used.
940    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
941        causing partial matching to fail when the end of the subject matched \W
942        in a UTF-8 pattern where \W was quantified with a minimum of 3.
944    15. There were some discrepancies between the declarations in pcre_internal.h
945        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
946        their definitions. The declarations used "const uschar *" and the
947        definitions used USPTR. Even though USPTR is normally defined as "const
948        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
949        reported that: "This difference in casting confuses some C++ compilers, for
950        example, SunCC recognizes above declarations as different functions and
951        generates broken code for hbpcre." I have changed the declarations to use
952        USPTR.
954    16. GNU libtool is named differently on some systems. The autogen.sh script now
955        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
956        (FreeBSD).
958    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
959        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
960        comment: "Figure out how to create a longlong from a string: strtoll and
961        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
962        instance, but it only takes 2 args instead of 3!"
964    18. A subtle bug concerned with back references has been fixed by a change of
965        specification, with a corresponding code fix. A pattern such as
966        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
967        refers, was giving matches when it shouldn't. For example, xa=xaaa would
968        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
969        same bug. Such groups have to be quantified to be useful, or contained
970        inside another quantified group. (If there's no repetition, the reference
971        can never match.) The problem arises because, having left the group and
972        moved on to the rest of the pattern, a later failure that backtracks into
973        the group uses the captured value from the final iteration of the group
974        rather than the correct earlier one. I have fixed this in PCRE by forcing
975        any group that contains a reference to itself to be an atomic group; that
976        is, there cannot be any backtracking into it once it has completed. This is
977        similar to recursive and subroutine calls.
980    Version 8.00 19-Oct-09
981    ----------------------
983    1.  The table for translating pcre_compile() error codes into POSIX error codes
984        was out-of-date, and there was no check on the pcre_compile() error code
985        being within the table. This could lead to an OK return being given in
986        error.
988    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
989        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
990        in a Windows environment.
992    3.  The pcregrep --count option prints the count for each file even when it is
993        zero, as does GNU grep. However, pcregrep was also printing all files when
994        --files-with-matches was added. Now, when both options are given, it prints
995        counts only for those files that have at least one match. (GNU grep just
996        prints the file name in this circumstance, but including the count seems
997        more useful - otherwise, why use --count?) Also ensured that the
998        combination -clh just lists non-zero counts, with no names.
1000    4.  The long form of the pcregrep -F option was incorrectly implemented as
1001        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1002        but it seems right to fix it, and I didn't think it was worth preserving
1003        the old behaviour.
1005    5.  The command line items --regex=pattern and --regexp=pattern were not
1006        recognized by pcregrep, which required --regex pattern or --regexp pattern
1007        (with a space rather than an '='). The man page documented the '=' forms,
1008        which are compatible with GNU grep; these now work.
1010    6.  No libpcreposix.pc file was created for pkg-config; there was just
1011        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1013    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1014        when UCP support is not needed, by modifying the Python script that
1015        generates it from Unicode data files. This should not matter if the module
1016        is correctly used as a library, but I received one complaint about 50K of
1017        unwanted data. My guess is that the person linked everything into his
1018        program rather than using a library. Anyway, it does no harm.
1020    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1021        was a minimum greater than 1 for a wide character in a possessive
1022        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1023        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1024        character. Chaos in the form of incorrect output or a compiling loop could
1025        result.
1027    9.  The restrictions on what a pattern can contain when partial matching is
1028        requested for pcre_exec() have been removed. All patterns can now be
1029        partially matched by this function. In addition, if there are at least two
1030        slots in the offset vector, the offset of the earliest inspected character
1031        for the match and the offset of the end of the subject are set in them when
1032        PCRE_ERROR_PARTIAL is returned.
1034    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1035        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1036        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1037        and may be more useful for multi-segment matching.
1039    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1040        used to be given if ever the end of the subject was reached; now it is
1041        given only if matching could not proceed because another character was
1042        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1043        string "Z", which now yields "no match" instead of "partial match". In the
1044        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1045        final character ended with (*FAIL).
1047    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1048        if the pattern had a "must contain" character that was already found in the
1049        earlier partial match, unless partial matching was again requested. For
1050        example, with the pattern /dog.(body)?/, the "must contain" character is
1051        "g". If the first part-match was for the string "dog", restarting with
1052        "sbody" failed. This bug has been fixed.
1054    13. The string returned by pcre_dfa_exec() after a partial match has been
1055        changed so that it starts at the first inspected character rather than the
1056        first character of the match. This makes a difference only if the pattern
1057        starts with a lookbehind assertion or \b or \B (\K is not supported by
1058        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1059        matching functions compatible, and I think it's the right thing to do.
1061    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1062        so that the demonstration program is easily available in environments where
1063        PCRE has not been installed from source.
1065    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1066        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1067        library.
1069    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1070        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1071        is not the first non-POSIX option to be added. Clearly some people find
1072        these options useful.
1074    17. If a caller to the POSIX matching function regexec() passes a non-zero
1075        value for nmatch with a NULL value for pmatch, the value of
1076        nmatch is forced to zero.
1078    18. RunGrepTest did not have a test for the availability of the -u option of
1079        the diff command, as RunTest does. It now checks in the same way as
1080        RunTest, and also checks for the -b option.
1082    19. If an odd number of negated classes containing just a single character
1083        interposed, within parentheses, between a forward reference to a named
1084        subpattern and the definition of the subpattern, compilation crashed with
1085        an internal error, complaining that it could not find the referenced
1086        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1087        [The bug was that it was starting one character too far in when skipping
1088        over the character class, thus treating the ] as data rather than
1089        terminating the class. This meant it could skip too much.]
1091    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1092        /g option in pcretest when the pattern contains \K, which makes it possible
1093        to have an empty string match not at the start, even when the pattern is
1094        anchored. Updated pcretest and pcredemo to use this option.
1096    21. If the maximum number of capturing subpatterns in a recursion was greater
1097        than the maximum at the outer level, the higher number was returned, but
1098        with unset values at the outer level. The correct (outer level) value is
1099        now given.
1101    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1102        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1103        make it do so. The string so far is captured, making this feature
1104        compatible with Perl.
1106    23. The tests have been re-organized, adding tests 11 and 12, to make it
1107        possible to check the Perl 5.10 features against Perl 5.10.
1109    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1110        pattern matches a fixed length string. PCRE did not allow this; now it
1111        does. Neither allows recursion.
1113    25. I finally figured out how to implement a request to provide the minimum
1114        length of subject string that was needed in order to match a given pattern.
1115        (It was back references and recursion that I had previously got hung up
1116        on.) This code has now been added to pcre_study(); it finds a lower bound
1117        to the length of subject needed. It is not necessarily the greatest lower
1118        bound, but using it to avoid searching strings that are too short does give
1119        some useful speed-ups. The value is available to calling programs via
1120        pcre_fullinfo().
1122    26. While implementing 25, I discovered to my embarrassment that pcretest had
1123        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1124        study optimizations had never been tested with that matching function.
1125        Oops. What is worse, even when it was passed study data, there was a bug in
1126        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1127        were also very few tests of studied patterns with pcre_dfa_exec().
1129    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1130        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1131        on the other side of the coin, they are no longer allowed to have different
1132        names, because these cannot be distinguished in PCRE, and this has caused
1133        confusion. (This is a difference from Perl.)
1135    28. When duplicate subpattern names are present (necessarily with different
1136        numbers, as required by 27 above), and a test is made by name in a
1137        conditional pattern, either for a subpattern having been matched, or for
1138        recursion in such a pattern, all the associated numbered subpatterns are
1139        tested, and the overall condition is true if the condition is true for any
1140        one of them. This is the way Perl works, and is also more like the way
1141        testing by number works.
1144    Version 7.9 11-Apr-09
1145    ---------------------
1147    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1148        (pcretest), all targets were linked against these libraries. This included
1149        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1150        libraries. This caused unwanted dependencies to be created. This problem
1151        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1152        pcretest is linked with readline.
1154    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1155        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1156        moved outside it again, because FALSE and TRUE are already defined in AIX,
1157        but BOOL is not.
1159    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1160        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1162    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1163        hyphens) following file names and line numbers when outputting matching
1164        lines. This is not true; no spaces are inserted. I have also clarified the
1165        wording for the --colour (or --color) option.
1167    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1168        was not coloured; this is different to GNU grep, so I have changed it to be
1169        the same.
1171    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1172        each matching line was coloured. Now it goes on to look for further matches
1173        of any of the test patterns, which is the same behaviour as GNU grep.
1175    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1176        doesn't make sense to accept an empty string match in pcregrep, so I have
1177        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1178        seems to be how GNU grep behaves.
1180    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1181        start or after a newline", because the conditional assertion was not being
1182        correctly handled. The rule now is that both the assertion and what follows
1183        in the first alternative must satisfy the test.
1185    9.  If auto-callout was enabled in a pattern with a conditional group whose
1186        condition was an assertion, PCRE could crash during matching, both with
1187        pcre_exec() and pcre_dfa_exec().
1189    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1190        used for matching.
1192    11. Unicode property support in character classes was not working for
1193        characters (bytes) greater than 127 when not in UTF-8 mode.
1195    12. Added the -M command line option to pcretest.
1197    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1199    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1201    16. Added comments and documentation about mis-use of no_arg in the C++
1202        wrapper.
1204    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1205        from Martin Jerabek that uses macro names for all relevant character and
1206        string constants.
1208    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1209        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1210        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1211        these, but not everybody uses configure.
1213    19. A conditional group that had only one branch was not being correctly
1214        recognized as an item that could match an empty string. This meant that an
1215        enclosing group might also not be so recognized, causing infinite looping
1216        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1217        with the subject "ab", where knowledge that the repeated group can match
1218        nothing is needed in order to break the loop.
1220    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1221        exec(), but without supplying a callout function, matching went wrong.
1223    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1224        leak if the size of the offset vector was greater than 30. When the vector
1225        is smaller, the saved offsets during recursion go onto a local stack
1226        vector, but for larger vectors malloc() is used. It was failing to free
1227        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1228        error, in fact).
1230    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1231        heapframe that is used only when UTF-8 support is enabled. This caused no
1232        problem, but was untidy.
1234    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1235        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1236        included within another project.
1238    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1239        slightly modified by me:
1241          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1242              not building pcregrep.
1244          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1245              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1247    25. Forward references, both numeric and by name, in patterns that made use of
1248        duplicate group numbers, could behave incorrectly or give incorrect errors,
1249        because when scanning forward to find the reference group, PCRE was not
1250        taking into account the duplicate group numbers. A pattern such as
1251        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1253    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1254        the feature of a custom pointer more persuasive (as requested by a user).
1256    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1257        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1258        pre-defined.
1260    28. Added support for (*UTF8) at the start of a pattern.
1262    29. Arrange for flags added by the "release type" setting in CMake to be shown
1263        in the configuration summary.
1266    Version 7.8 05-Sep-08
1267    ---------------------
1269    1.  Replaced UCP searching code with optimized version as implemented for Ad
1270        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1271        stage table and inline lookup instead of a function, giving speed ups of 2
1272        to 5 times on some simple patterns that I tested. Permission was given to
1273        distribute the MultiStage2.py script that generates the tables (it's not in
1274        the tarball, but is in the Subversion repository).
1276    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1277        scripts.
1279    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1280        a group with a zero qualifier. The result of the study could be incorrect,
1281        or the function might crash, depending on the pattern.
1283    4.  Caseless matching was not working for non-ASCII characters in back
1284        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1285        It now works when Unicode Property Support is available.
1287    5.  In pcretest, an escape such as \x{de} in the data was always generating
1288        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1289        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1290        truncation.
1292    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1294    7.  Added two (int) casts to pcregrep when printing the difference of two
1295        pointers, in case they are 64-bit values.
1297    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1298        test 2 if it fails.
1300    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1301        and a #define of that name to empty if it is not externally set. This is to
1302        allow users of MSVC to set it if necessary.
1304    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1305        the convenience functions in the pcre_get.c source file.
1307    11. An option change at the start of a pattern that had top-level alternatives
1308        could cause overwriting and/or a crash. This command provoked a crash in
1309        some environments:
1311          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1313        This potential security problem was recorded as CVE-2008-2371.
1315    12. For a pattern where the match had to start at the beginning or immediately
1316        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1317        pcre_dfa_exec() could read past the end of the passed subject if there was
1318        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1319        pcretest so that it places the subject at the end of its malloc-ed buffer.
1321    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1322        exec() might read past the end of the data buffer in UTF-8 mode.
1324    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1325        the data contained the byte 0x85 as part of a UTF-8 character within its
1326        first line. This applied both to normal and DFA matching.
1328    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1329        /^[^d]*?$/8 failed to match "abc".
1331    16. Added a missing copyright notice to pcrecpp_internal.h.
1333    17. Make it more clear in the documentation that values returned from
1334        pcre_exec() in ovector are byte offsets, not character counts.
1336    18. Tidied a few places to stop certain compilers from issuing warnings.
1338    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1339        supplied by Stefan Weber. I made a further small update for 7.8 because
1340        there is a change of source arrangements: the pcre_searchfuncs.c module is
1341        replaced by pcre_ucd.c.
1344    Version 7.7 07-May-08
1345    ---------------------
1347    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1348        a string to a long long, pretend we don't even have a long long." This is
1349        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1351    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1352        pre-7.6 versions, which defined a global no_arg variable instead of putting
1353        it in the RE class. (See also #8 below.)
1355    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1356        Lopes.
1358    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1360        (1) The include/exclude patterns were being applied to the whole pathnames
1361            of files, instead of just to the final components.
1363        (2) If there was more than one level of directory, the subdirectories were
1364            skipped unless they satisfied the include/exclude conditions. This is
1365            inconsistent with GNU grep (and could even be seen as contrary to the
1366            pcregrep specification - which I improved to make it absolutely clear).
1367            The action now is always to scan all levels of directory, and just
1368            apply the include/exclude patterns to regular files.
1370    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1371        --exclude_dir in the tests to avoid scanning .svn directories.
1373    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1374        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1375        doesn't support NULs in patterns.
1377    7.  Added some missing "const"s to declarations of static tables in
1378        pcre_compile.c and pcre_dfa_exec.c.
1380    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1381        caused by fix #2  above. (Subsequently also a second patch to fix the
1382        first patch. And a third patch - this was a messy problem.)
1384    9.  Applied Craig's patch to remove the use of push_back().
1386    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1387        matching function regexec().
1389    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1390        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1391        references. PCRE supports relative numbers with this syntax (I don't think
1392        Oniguruma does).
1394    12. Previously, a group with a zero repeat such as (...){0} was completely
1395        omitted from the compiled regex. However, this means that if the group
1396        was called as a subroutine from elsewhere in the pattern, things went wrong
1397        (an internal error was given). Such groups are now left in the compiled
1398        pattern, with a new opcode that causes them to be skipped at execution
1399        time.
1401    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1402        to the way PCRE behaves:
1404        (a) A lone ] character is dis-allowed (Perl treats it as data).
1406        (b) A back reference to an unmatched subpattern matches an empty string
1407            (Perl fails the current match path).
1409        (c) A data ] in a character class must be notated as \] because if the
1410            first data character in a class is ], it defines an empty class. (In
1411            Perl it is not possible to have an empty class.) The empty class []
1412            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1413            The negative empty class [^] matches any one character, independently
1414            of the DOTALL setting.
1416    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1417        non-existent subpattern following a character class starting with ']' and
1418        containing () gave an internal compiling error instead of "reference to
1419        non-existent subpattern". Fortunately, when the pattern did exist, the
1420        compiled code was correct. (When scanning forwards to check for the
1421        existencd of the subpattern, it was treating the data ']' as terminating
1422        the class, so got the count wrong. When actually compiling, the reference
1423        was subsequently set up correctly.)
1425    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1426        it was being rejected as not supported by pcre_dfa_exec(), even though
1427        other assertions are supported. I have made pcre_dfa_exec() support
1428        (*FAIL).
1430    16. The implementation of 13c above involved the invention of a new opcode,
1431        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1432        cannot be changed at match time, I realized I could make a small
1433        improvement to matching performance by compiling OP_ALLANY instead of
1434        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1435        on the OP_ANY path.
1437    17. Compiling pcretest on Windows with readline support failed without the
1438        following two fixes: (1) Make the unistd.h include conditional on
1439        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1441    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1442        ncurses library to be included for pcretest when ReadLine support is
1443        requested, but also to allow for it to be overridden. This patch came from
1444        Daniel Bergström.
1446    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1447        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1448        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1449        spotting this.
1452    Version 7.6 28-Jan-08
1453  ---------------------  ---------------------
1455  1.  A character class containing a very large number of characters with  1.  A character class containing a very large number of characters with
# Line 16  Version 7.6 21-Jan-08 Line 1464  Version 7.6 21-Jan-08
1465      - Fixed PH's badly added libz and libbz2 support.      - Fixed PH's badly added libz and libbz2 support.
1466      - Fixed a problem with static linking.      - Fixed a problem with static linking.
1467      - Added pcredemo.      - Added pcredemo. [But later removed - see 7 below.]
1468      - Fixed dftables problem and added an option.      - Fixed dftables problem and added an option.
1469      - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and      - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1470          HAVE_LONG_LONG.          HAVE_LONG_LONG.
1471      - Added readline support for pcretest.      - Added readline support for pcretest.
1472      - Added an listing of the option settings after cmake has run.      - Added an listing of the option settings after cmake has run.
1474  4.  A user submitted a patch to Makefile that makes it easy to created a dll  4.  A user submitted a patch to Makefile that makes it easy to create
1475      under mingw. I added stuff to Makefile.am that cause it to include this      "pcre.dll" under mingw when using Configure/Make. I added stuff to
1476      special target, without affecting anything else.      Makefile.am that cause it to include this special target, without
1477        affecting anything else. Note that the same mingw target plus all
1478        the other distribution libraries and programs are now supported
1479        when configuring with CMake (see 6 below) instead of with
1480        Configure/Make.
1482  5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.  5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1483      This is an attempt to solve the reported problem "pcrecpp::no_arg is not      This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1484      exported in the Windows port". It has not yet been confirmed that the patch      exported in the Windows port". It has not yet been confirmed that the patch
1485      solves the problem, but it does no harm.      solves the problem, but it does no harm.
1487    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1488        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1489        with CMake, and also correct the comment about stack recursion.
1491    7.  Remove the automatic building of pcredemo from the ./configure system and
1492        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1493        of a program that users should build themselves after PCRE is installed, so
1494        building it automatically is not really right. What is more, it gave
1495        trouble in some build environments.
1497    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1500  Version 7.5 10-Jan-08  Version 7.5 10-Jan-08
1501  ---------------------  ---------------------

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