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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    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
1456        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1457        overflow.
1459    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1460        HAVE_LONG_LONG is not defined.
1462    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1463        bring them up to date and include new features. This patch includes:
1465        - Fixed PH's badly added libz and libbz2 support.
1466        - Fixed a problem with static linking.
1467        - Added pcredemo. [But later removed - see 7 below.]
1468        - Fixed dftables problem and added an option.
1469        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1470            HAVE_LONG_LONG.
1471        - Added readline support for pcretest.
1472        - 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 create
1475        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1476        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.
1483        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
1485        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
1501    ---------------------
1503    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1504        values in parens when parsing an RE using the C++ wrapper."
1506    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1507        Characters greater than 255 were excluded from the class instead of being
1508        included.
1510    3.  The same bug as (2) above applied to negated POSIX classes such as
1511        [:^space:].
1513    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1514        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1515        I have changed it.
1517    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1518        first named subpattern) and a construct such as (?&a) would reference the
1519        first named subpattern whose name started with "a" (in other words, the
1520        length check was missing). Both these problems are fixed. "Subpattern name
1521        expected" is now given for (?&) (a zero-length name), and this patch also
1522        makes it give the same error for \k'' (previously it complained that that
1523        was a reference to a non-existent subpattern).
1525    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1526        this is right because (?- can be followed by option settings as well as by
1527        digits. I have, however, made the messages clearer.
1529    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1530        than the number used in the conditional) now cause a compile-time error.
1531        This is actually not compatible with Perl, which accepts such patterns, but
1532        treats the conditional as always being FALSE (as PCRE used to), but it
1533        seems to me that giving a diagnostic is better.
1535    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1536        and messages.
1538    9.  Fix two occurrences of "backslash" in comments that should have been
1539        "backspace".
1541    10. Remove two redundant lines of code that can never be obeyed (their function
1542        was moved elsewhere).
1544    11. The program that makes PCRE's Unicode character property table had a bug
1545        which caused it to generate incorrect table entries for sequences of
1546        characters that have the same character type, but are in different scripts.
1547        It amalgamated them into a single range, with the script of the first of
1548        them. In other words, some characters were in the wrong script. There were
1549        thirteen such cases, affecting characters in the following ranges:
1551          U+002b0 - U+002c1
1552          U+0060c - U+0060d
1553          U+0061e - U+00612
1554          U+0064b - U+0065e
1555          U+0074d - U+0076d
1556          U+01800 - U+01805
1557          U+01d00 - U+01d77
1558          U+01d9b - U+01dbf
1559          U+0200b - U+0200f
1560          U+030fc - U+030fe
1561          U+03260 - U+0327f
1562          U+0fb46 - U+0fbb1
1563          U+10450 - U+1049d
1565    12. The -o option (show only the matching part of a line) for pcregrep was not
1566        compatible with GNU grep in that, if there was more than one match in a
1567        line, it showed only the first of them. It now behaves in the same way as
1568        GNU grep.
1570    13. If the -o and -v options were combined for pcregrep, it printed a blank
1571        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1572        does the same. The return code can be used to tell if there were any
1573        non-matching lines.
1575    14. Added --file-offsets and --line-offsets to pcregrep.
1577    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1578        infinitely looping recursion. The bug was that positive lookaheads were not
1579        being skipped when checking for a possible empty match (negative lookaheads
1580        and both kinds of lookbehind were skipped).
1582    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1583        inclusion of <windows.h> to before rather than after the definition of
1584        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1586    17. Specifying a possessive quantifier with a specific limit for a Unicode
1587        character property caused pcre_compile() to compile bad code, which led at
1588        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1589        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1590        caused the error; without that there was no problem.
1592    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1594    19. Added --enable-pcretest-libreadline.
1596    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1597        RE::GlobalReplace(). As a result, the number of replacements returned was
1598        double what it should be. I removed one of the increments, but Craig sent a
1599        later patch that removed the other one (the right fix) and added unit tests
1600        that check the return values (which was not done before).
1602    21. Several CMake things:
1604        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1605            the names libpcre and libpcreposix, not just pcre and pcreposix.
1607        (2) The above change means that pcretest and pcregrep are now correctly
1608            linked with the newly-built libraries, not previously installed ones.
1612    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1613        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1614        UTF-8 newline character). The key issue is that the pattern starts .*;
1615        this means that the match must be either at the beginning, or after a
1616        newline. The bug was in the code for advancing after a failed match and
1617        checking that the new position followed a newline. It was not taking
1618        account of UTF-8 characters correctly.
1620    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1621        character classes. PCRE was not treating the sequence [:...:] as a
1622        character class unless the ... were all letters. Perl, however, seems to
1623        allow any characters between [: and :], though of course it rejects as
1624        unknown any "names" that contain non-letters, because all the known class
1625        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1626        for example, whereas PCRE did not - it did not recognize a POSIX character
1627        class. This seemed a bit dangerous, so the code has been changed to be
1628        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1629        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1630        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1631        Perl does, and where it didn't before.
1633    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1634        Windows environments %n is disabled by default.
1637    Version 7.4 21-Sep-07
1638    ---------------------
1640    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1641        means that a class such as [\s] counted as "explicit reference to CR or
1642        LF". That isn't really right - the whole point of the change was to try to
1643        help when there was an actual mention of one of the two characters. So now
1644        the change happens only if \r or \n (or a literal CR or LF) character is
1645        encountered.
1647    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1648        of both had grown to the point where there were only 3 bits left.
1649        Fortunately, there was spare space in the data structure, and so I have
1650        moved the internal flags into a new 16-bit field to free up more option
1651        bits.
1653    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1654        but did not set the internal JCHANGED flag - either of these is enough to
1655        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1656        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1657        start sets both bits.
1659    4.  Added options (at build time, compile time, exec time) to change \R from
1660        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1662    5.  doc/pcresyntax.html was missing from the distribution.
1664    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1665        compatibility, even though it is no longer used.
1667    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1668        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1669        windows.h file is present (where different names are used). [This was
1670        reversed later after testing - see 16 below.]
1672    8.  Changed all #include <config.h> to #include "config.h". There were also
1673        some further <pcre.h> cases that I changed to "pcre.h".
1675    9.  When pcregrep was used with the --colour option, it missed the line ending
1676        sequence off the lines that it output.
1678    10. It was pointed out to me that arrays of string pointers cause lots of
1679        relocations when a shared library is dynamically loaded. A technique of
1680        using a single long string with a table of offsets can drastically reduce
1681        these. I have refactored PCRE in four places to do this. The result is
1682        dramatic:
1684          Originally:                          290
1685          After changing UCP table:            187
1686          After changing error message table:   43
1687          After changing table of "verbs"       36
1688          After changing table of Posix names   22
1690        Thanks to the folks working on Gregex for glib for this insight.
1692    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1693        unicode-properties was also set.
1695    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1697    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1698        checked only for CRLF.
1700    14. Added casts to pcretest.c to avoid compiler warnings.
1702    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1704    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1705        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1706        entirely. This removes changes made in 7 above.
1708    17. The CMake files have been updated, and there is now more information about
1709        building with CMake in the NON-UNIX-USE document.
1712    Version 7.3 28-Aug-07
1713    ---------------------
1715     1. In the rejigging of the build system that eventually resulted in 7.1, the
1716        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1717        brackets there is not right, since it causes compilers to look for an
1718        installed pcre.h, not the version that is in the source that is being
1719        compiled (which of course may be different). I have changed it back to:
1721          #include "pcre.h"
1723        I have a vague recollection that the change was concerned with compiling in
1724        different directories, but in the new build system, that is taken care of
1725        by the VPATH setting the Makefile.
1727     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1728        when the subject happened to end in the byte 0x85 (e.g. if the last
1729        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1730        characters but of course it shouldn't be taken as a newline when it is part
1731        of another character. The bug was that, for an unlimited repeat of . in
1732        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1733        characters when looking for a newline.
1735     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1737     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1738        in debug output.
1740     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1741        long printing in the pcrecpp unittest when running under MinGW.
1743     6. ESC_K was left out of the EBCDIC table.
1745     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1746        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1747        limit also applies to "virtual nesting" when a pattern is recursive, and in
1748        this case 1000 isn't so big. I have been able to remove this limit at the
1749        expense of backing off one optimization in certain circumstances. Normally,
1750        when pcre_exec() would call its internal match() function recursively and
1751        immediately return the result unconditionally, it uses a "tail recursion"
1752        feature to save stack. However, when a subpattern that can match an empty
1753        string has an unlimited repetition quantifier, it no longer makes this
1754        optimization. That gives it a stack frame in which to save the data for
1755        checking that an empty string has been matched. Previously this was taken
1756        from the 1000-entry workspace that had been reserved. So now there is no
1757        explicit limit, but more stack is used.
1759     8. Applied Daniel's patches to solve problems with the import/export magic
1760        syntax that is required for Windows, and which was going wrong for the
1761        pcreposix and pcrecpp parts of the library. These were overlooked when this
1762        problem was solved for the main library.
1764     9. There were some crude static tests to avoid integer overflow when computing
1765        the size of patterns that contain repeated groups with explicit upper
1766        limits. As the maximum quantifier is 65535, the maximum group length was
1767        set at 30,000 so that the product of these two numbers did not overflow a
1768        32-bit integer. However, it turns out that people want to use groups that
1769        are longer than 30,000 bytes (though not repeat them that many times).
1770        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1771        made it possible to implement the integer overflow checks in a much more
1772        dynamic way, which I have now done. The artificial limitation on group
1773        length has been removed - we now have only the limit on the total length of
1774        the compiled pattern, which depends on the LINK_SIZE setting.
1776    10. Fixed a bug in the documentation for get/copy named substring when
1777        duplicate names are permitted. If none of the named substrings are set, the
1778        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1779        empty string.
1781    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1782        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1783        because the ] is interpreted as the first data character and the
1784        terminating ] is not found. PCRE has been made compatible with Perl in this
1785        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1786        cause memory overwriting.
1788    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1789        string has been matched (to stop an infinite loop). It was not recognizing
1790        a conditional subpattern that could match an empty string if that
1791        subpattern was within another subpattern. For example, it looped when
1792        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1793        condition was not nested. This bug has been fixed.
1795    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1796        past the start of the subject in the presence of bytes with the top bit
1797        set, for example "\x8aBCD".
1799    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1800        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1802    14. Optimized (?!) to (*FAIL).
1804    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1805        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1806        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1807        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1808        does: it's just the validity check that is more restrictive.
1810    16. Inserted checks for integer overflows during escape sequence (backslash)
1811        processing, and also fixed erroneous offset values for syntax errors during
1812        backslash processing.
1814    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1815        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1817    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1818        caused an overrun.
1820    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1821        something other than just ASCII characters) inside a group that had an
1822        unlimited repeat caused a loop at compile time (while checking to see
1823        whether the group could match an empty string).
1825    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1826        [\P{Any}] did so. (Error in the code for printing property names.)
1828    21. An orphan \E inside a character class could cause a crash.
1830    22. A repeated capturing bracket such as (A)? could cause a wild memory
1831        reference during compilation.
1833    23. There are several functions in pcre_compile() that scan along a compiled
1834        expression for various reasons (e.g. to see if it's fixed length for look
1835        behind). There were bugs in these functions when a repeated \p or \P was
1836        present in the pattern. These operators have additional parameters compared
1837        with \d, etc, and these were not being taken into account when moving along
1838        the compiled data. Specifically:
1840        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1841            length.
1843        (b) An item such as \pL+ within a repeated group could cause crashes or
1844            loops.
1846        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1847            "reference to non-existent subpattern" error.
1849        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1851    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1852        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1854    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1856    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1857        character were causing crashes (broken optimization).
1859    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1860        \p or \P) caused a compile-time loop.
1862    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1863        break. For example, the unstudied pattern [\r\n]A does not match the string
1864        "\r\nA" because change 7.0/46 below moves the current point on by two
1865        characters after failing to match at the start. However, the pattern \nA
1866        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1867        the same is true. There doesn't seem any very clean way out of this, but
1868        what I have chosen to do makes the common cases work: PCRE now takes note
1869        of whether there can be an explicit match for \r or \n anywhere in the
1870        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1871        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1872        pattern has explicit CR or LF references.
1874    29. Added (*CR) etc for changing newline setting at start of pattern.
1877    Version 7.2 19-Jun-07
1878    ---------------------
1880     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1881        which is apparently normally available under Windows.
1883     2. Re-jig the pcregrep tests with different newline settings in an attempt
1884        to make them independent of the local environment's newline setting.
1886     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1888     4. Some of the "internals" tests were previously cut out when the link size
1889        was not 2, because the output contained actual offsets. The recent new
1890        "Z" feature of pcretest means that these can be cut out, making the tests
1891        usable with all link sizes.
1893     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1894        stack recursion. This gives a massive performance boost under BSD, but just
1895        a small improvement under Linux. However, it saves one field in the frame
1896        in all cases.
1898     6. Added more features from the forthcoming Perl 5.10:
1900        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1901            recursion call. It refers to the nth most recently opened parentheses.
1903        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1904            to be opened parentheses.
1906        (c) Conditions that refer to capturing parentheses can be specified
1907            relatively, for example, (?(-2)... or (?(+3)...
1909        (d) \K resets the start of the current match so that everything before
1910            is not part of it.
1912        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1914        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1915            reference syntax.
1917        (g) (?| introduces a group in which the numbering of parentheses in each
1918            alternative starts with the same number.
1920        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1922     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1925     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1926        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1927        for detecting groups that can match an empty string.
1929     9. A pattern with a very large number of alternatives (more than several
1930        hundred) was running out of internal workspace during the pre-compile
1931        phase, where pcre_compile() figures out how much memory will be needed. A
1932        bit of new cunning has reduced the workspace needed for groups with
1933        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1934        workspace instead of running out of the 4096 that are available.
1936    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1938    11. Applied patch from Google to remove an optimization that didn't quite work.
1939        The report of the bug said:
1941          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1942          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1943          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1945    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1946        it matched the wrong number of bytes.
1949    Version 7.1 24-Apr-07
1950    ---------------------
1952     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1953        that is more "standard", making use of automake and other Autotools. There
1954        is some re-arrangement of the files and adjustment of comments consequent
1955        on this.
1957     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1958        for recursive directory scanning broke on some systems because the files
1959        are not scanned in any specific order and on different systems the order
1960        was different. A call to "sort" has been inserted into RunGrepTest for the
1961        approprate test as a short-term fix. In the longer term there may be an
1962        alternative.
1964     3. I had an email from Eric Raymond about problems translating some of PCRE's
1965        man pages to HTML (despite the fact that I distribute HTML pages, some
1966        people do their own conversions for various reasons). The problems
1967        concerned the use of low-level troff macros .br and .in. I have therefore
1968        removed all such uses from the man pages (some were redundant, some could
1969        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1970        HTML has been updated to handle .nf/.fi and to complain if it encounters
1971        .br or .in.
1973     4. Updated comments in configure.ac that get placed in config.h.in and also
1974        arranged for config.h to be included in the distribution, with the name
1975        config.h.generic, for the benefit of those who have to compile without
1976        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1978     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1979        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1980        makevp.bat for the current PCRE, using the additional files
1981        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1983     6. A Windows user reported a minor discrepancy with test 2, which turned out
1984        to be caused by a trailing space on an input line that had got lost in his
1985        copy. The trailing space was an accident, so I've just removed it.
1987     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1988        that is needed.
1990     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1991        as "const" (a) because they are and (b) because it helps the PHP
1992        maintainers who have recently made a script to detect big data structures
1993        in the php code that should be moved to the .rodata section. I remembered
1994        to update Builducptable as well, so it won't revert if ucptable.h is ever
1995        re-created.
1997     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1998        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1999        order to be able to cut out the UTF-8 tables in the latter when UTF-8
2000        support is not required. This saves 1.5-2K of code, which is important in
2001        some applications.
2003        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2004        so as not to refer to the tables, even though these functions will never be
2005        called when UTF-8 support is disabled. Otherwise there are problems with a
2006        shared library.
2008    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2010        (a) It was defining its arguments as char * instead of void *.
2012        (b) It was assuming that all moves were upwards in memory; this was true
2013            a long time ago when I wrote it, but is no longer the case.
2015        The emulated memove() is provided for those environments that have neither
2016        memmove() nor bcopy(). I didn't think anyone used it these days, but that
2017        is clearly not the case, as these two bugs were recently reported.
2019    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2020        and Detrail to create the HTML documentation, the .txt form of the man
2021        pages, and it removes trailing spaces from listed files. It also creates
2022        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2023        case, it wraps all the #defines with #ifndefs. This script should be run
2024        before "make dist".
2026    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2027        with Unicode property support.
2029        (a) For a maximizing quantifier, if the two different cases of the
2030            character were of different lengths in their UTF-8 codings (there are
2031            some cases like this - I found 11), and the matching function had to
2032            back up over a mixture of the two cases, it incorrectly assumed they
2033            were both the same length.
2035        (b) When PCRE was configured to use the heap rather than the stack for
2036            recursion during matching, it was not correctly preserving the data for
2037            the other case of a UTF-8 character when checking ahead for a match
2038            while processing a minimizing repeat. If the check also involved
2039            matching a wide character, but failed, corruption could cause an
2040            erroneous result when trying to check for a repeat of the original
2041            character.
2043    13. Some tidying changes to the testing mechanism:
2045        (a) The RunTest script now detects the internal link size and whether there
2046            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2047            values substituted by "configure". (The RunGrepTest script already did
2048            this for UTF-8.) The configure.ac script no longer substitutes the
2049            relevant variables.
2051        (b) The debugging options /B and /D in pcretest show the compiled bytecode
2052            with length and offset values. This means that the output is different
2053            for different internal link sizes. Test 2 is skipped for link sizes
2054            other than 2 because of this, bypassing the problem. Unfortunately,
2055            there was also a test in test 3 (the locale tests) that used /B and
2056            failed for link sizes other than 2. Rather than cut the whole test out,
2057            I have added a new /Z option to pcretest that replaces the length and
2058            offset values with spaces. This is now used to make test 3 independent
2059            of link size. (Test 2 will be tidied up later.)
2061    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2062        segmentation fault instead of returning the appropriate error message.
2064    15. In multiline mode when the newline sequence was set to "any", the pattern
2065        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2066        This doesn't seem right; it now treats the CRLF combination as the line
2067        ending, and so does not match in that case. It's only a pattern such as ^$
2068        that would hit this one: something like ^ABC$ would have failed after \r
2069        and then tried again after \r\n.
2071    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2072        in an attempt to make files that differ only in their line terminators
2073        compare equal. This works on Linux.
2075    17. Under certain error circumstances pcregrep might try to free random memory
2076        as it exited. This is now fixed, thanks to valgrind.
2078    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2079        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2080        was because its rules for how to advance for /g after matching an empty
2081        string at the end of a line did not allow for this case. They now check for
2082        it specially.
2084    20. pcretest is supposed to handle patterns and data of any length, by
2085        extending its buffers when necessary. It was getting this wrong when the
2086        buffer for a data line had to be extended.
2088    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2089        CRLF as a newline sequence.
2091    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2092        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2093        I have nevertheless tidied it up.
2095    23. Added some casts to kill warnings from HP-UX ia64 compiler.
2097    24. Added a man page for pcre-config.
2100    Version 7.0 19-Dec-06
2101    ---------------------
2103     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2104        moving to gcc 4.1.1.
2106     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2107        sys/time.h, which is documented as needed for this function. It doesn't
2108        seem to matter on Linux, but it showed up on some releases of OS X.
2110     3. It seems that there are systems where bytes whose values are greater than
2111        127 match isprint() in the "C" locale. The "C" locale should be the
2112        default when a C program starts up. In most systems, only ASCII printing
2113        characters match isprint(). This difference caused the output from pcretest
2114        to vary, making some of the tests fail. I have changed pcretest so that:
2116        (a) When it is outputting text in the compiled version of a pattern, bytes
2117            other than 32-126 are always shown as hex escapes.
2119        (b) When it is outputting text that is a matched part of a subject string,
2120            it does the same, unless a different locale has been set for the match
2121            (using the /L modifier). In this case, it uses isprint() to decide.
2123     4. Fixed a major bug that caused incorrect computation of the amount of memory
2124        required for a compiled pattern when options that changed within the
2125        pattern affected the logic of the preliminary scan that determines the
2126        length. The relevant options are -x, and -i in UTF-8 mode. The result was
2127        that the computed length was too small. The symptoms of this bug were
2128        either the PCRE error "internal error: code overflow" from pcre_compile(),
2129        or a glibc crash with a message such as "pcretest: free(): invalid next
2130        size (fast)". Examples of patterns that provoked this bug (shown in
2131        pcretest format) are:
2133          /(?-x: )/x
2134          /(?x)(?-x: \s*#\s*)/
2135          /((?i)[\x{c0}])/8
2136          /(?i:[\x{c0}])/8
2138        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2139        is now done differently.
2141     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2142        wrapper classes; (b) implement a new function in the C++ scanner that is
2143        more efficient than the old way of doing things because it avoids levels of
2144        recursion in the regex matching; (c) add a paragraph to the documentation
2145        for the FullMatch() function.
2147     6. The escape sequence \n was being treated as whatever was defined as
2148        "newline". Not only was this contrary to the documentation, which states
2149        that \n is character 10 (hex 0A), but it also went horribly wrong when
2150        "newline" was defined as CRLF. This has been fixed.
2152     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2153        was being set to -1 for the "end of line" case (supposedly a value that no
2154        character can have). Though this value is never used (the check for end of
2155        line is "zero bytes in current character"), it caused compiler complaints.
2156        I've changed it to 0xffffffff.
2158     8. In pcre_version.c, the version string was being built by a sequence of
2159        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2160        string (as it is for production releases) called a macro with an empty
2161        argument. The C standard says the result of this is undefined. The gcc
2162        compiler treats it as an empty string (which was what was wanted) but it is
2163        reported that Visual C gives an error. The source has been hacked around to
2164        avoid this problem.
2166     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2167        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2168        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2169        of them did).
2171    10. Originally, pcretest opened its input and output without "b"; then I was
2172        told that "b" was needed in some environments, so it was added for release
2173        5.0 to both the input and output. (It makes no difference on Unix-like
2174        systems.) Later I was told that it is wrong for the input on Windows. I've
2175        now abstracted the modes into two macros, to make it easier to fiddle with
2176        them, and removed "b" from the input mode under Windows.
2178    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2180    12. Added -help and --help to pcretest as an official way of being reminded
2181        of the options.
2183    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2184        and pcrecpp.cc because they annoy compilers at high warning levels.
2186    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2188    15. Fixed an occurrence of == in configure.ac that should have been = (shell
2189        scripts are not C programs :-) and which was not noticed because it works
2190        on Linux.
2192    16. pcretest is supposed to handle any length of pattern and data line (as one
2193        line or as a continued sequence of lines) by extending its input buffer if
2194        necessary. This feature was broken for very long pattern lines, leading to
2195        a string of junk being passed to pcre_compile() if the pattern was longer
2196        than about 50K.
2198    17. I have done a major re-factoring of the way pcre_compile() computes the
2199        amount of memory needed for a compiled pattern. Previously, there was code
2200        that made a preliminary scan of the pattern in order to do this. That was
2201        OK when PCRE was new, but as the facilities have expanded, it has become
2202        harder and harder to keep it in step with the real compile phase, and there
2203        have been a number of bugs (see for example, 4 above). I have now found a
2204        cunning way of running the real compile function in a "fake" mode that
2205        enables it to compute how much memory it would need, while actually only
2206        ever using a few hundred bytes of working memory and without too many
2207        tests of the mode. This should make future maintenance and development
2208        easier. A side effect of this work is that the limit of 200 on the nesting
2209        depth of parentheses has been removed (though this was never a serious
2210        limitation, I suspect). However, there is a downside: pcre_compile() now
2211        runs more slowly than before (30% or more, depending on the pattern). I
2212        hope this isn't a big issue. There is no effect on runtime performance.
2214    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2215        newline (only possible for the last line of a file) and it was a
2216        pattern that set a locale (followed by /Lsomething), pcretest crashed.
2218    19. Added additional timing features to pcretest. (1) The -tm option now times
2219        matching only, not compiling. (2) Both -t and -tm can be followed, as a
2220        separate command line item, by a number that specifies the number of
2221        repeats to use when timing. The default is 50000; this gives better
2222        precision, but takes uncomfortably long for very large patterns.
2224    20. Extended pcre_study() to be more clever in cases where a branch of a
2225        subpattern has no definite first character. For example, (a*|b*)[cd] would
2226        previously give no result from pcre_study(). Now it recognizes that the
2227        first character must be a, b, c, or d.
2229    21. There was an incorrect error "recursive call could loop indefinitely" if
2230        a subpattern (or the entire pattern) that was being tested for matching an
2231        empty string contained only one non-empty item after a nested subpattern.
2232        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2233        incorrectly, because the \d was being skipped in the check.
2235    22. The pcretest program now has a new pattern option /B and a command line
2236        option -b, which is equivalent to adding /B to every pattern. This causes
2237        it to show the compiled bytecode, without the additional information that
2238        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2239        is the same as /B/I).
2241    23. A new optimization is now able automatically to treat some sequences such
2242        as a*b as a*+b. More specifically, if something simple (such as a character
2243        or a simple class like \d) has an unlimited quantifier, and is followed by
2244        something that cannot possibly match the quantified thing, the quantifier
2245        is automatically "possessified".
2247    24. A recursive reference to a subpattern whose number was greater than 39
2248        went wrong under certain circumstances in UTF-8 mode. This bug could also
2249        have affected the operation of pcre_study().
2251    25. Realized that a little bit of performance could be had by replacing
2252        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2254    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2256    27. Possessive quantifiers such as a++ were previously implemented by turning
2257        them into atomic groups such as ($>a+). Now they have their own opcodes,
2258        which improves performance. This includes the automatically created ones
2259        from 23 above.
2261    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2262        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2263        the first matched character to be a colon. This applied both to named and
2264        numbered groups.
2266    29. The ucpinternal.h header file was missing its idempotency #ifdef.
2268    30. I was sent a "project" file called libpcre.a.dev which I understand makes
2269        building PCRE on Windows easier, so I have included it in the distribution.
2271    31. There is now a check in pcretest against a ridiculously large number being
2272        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2273        loop, the loop is abandoned.
2275    32. Forward references to subpatterns in conditions such as (?(2)...) where
2276        subpattern 2 is defined later cause pcre_compile() to search forwards in
2277        the pattern for the relevant set of parentheses. This search went wrong
2278        when there were unescaped parentheses in a character class, parentheses
2279        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2281    33. "Subroutine" calls and backreferences were previously restricted to
2282        referencing subpatterns earlier in the regex. This restriction has now
2283        been removed.
2285    34. Added a number of extra features that are going to be in Perl 5.10. On the
2286        whole, these are just syntactic alternatives for features that PCRE had
2287        previously implemented using the Python syntax or my own invention. The
2288        other formats are all retained for compatibility.
2290        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2291            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2292            also .NET compatible.
2294        (b) A recursion or subroutine call to a named group can now be defined as
2295            (?&name) as well as (?P>name).
2297        (c) A backreference to a named group can now be defined as \k<name> or
2298            \k'name' as well as (?P=name). The new forms, as well as being in Perl
2299            5.10, are also .NET compatible.
2301        (d) A conditional reference to a named group can now use the syntax
2302            (?(<name>) or (?('name') as well as (?(name).
2304        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2305            groups (named and numbered) that are never evaluated inline, but can be
2306            called as "subroutines" from elsewhere. In effect, the DEFINE condition
2307            is always false. There may be only one alternative in such a group.
2309        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2310            as the simple (?(R). The condition is true only if the most recent
2311            recursion is that of the given number or name. It does not search out
2312            through the entire recursion stack.
2314        (g) The escape \gN or \g{N} has been added, where N is a positive or
2315            negative number, specifying an absolute or relative reference.
2317    35. Tidied to get rid of some further signed/unsigned compiler warnings and
2318        some "unreachable code" warnings.
2320    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2321        things, this adds five new scripts.
2323    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2324        There were also incompatibilities regarding the handling of \Q..\E inside
2325        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2326        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2328    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2329        matches an empty string, and forcibly breaks the loop. There were bugs in
2330        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
2331        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
2332        separate and independent bugs (that affected different cases) have been
2333        fixed.
2335    39. Refactored the code to abolish the use of different opcodes for small
2336        capturing bracket numbers. This is a tidy that I avoided doing when I
2337        removed the limit on the number of capturing brackets for 3.5 back in 2001.
2338        The new approach is not only tidier, it makes it possible to reduce the
2339        memory needed to fix the previous bug (38).
2341    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2342        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2343        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2344        mode.
2346    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2347        report.
2349    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2350        copy construction and assignment in the C++ wrapper.
2352    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2353        couple of bugs that could have given wrong results in the "--newline=crlf"
2354        case.
2356    44. Added a number of casts and did some reorganization of signed/unsigned int
2357        variables following suggestions from Dair Grant. Also renamed the variable
2358        "this" as "item" because it is a C++ keyword.
2360    45. Arranged for dftables to add
2362          #include "pcre_internal.h"
2364        to pcre_chartables.c because without it, gcc 4.x may remove the array
2365        definition from the final binary if PCRE is built into a static library and
2366        dead code stripping is activated.
2368    46. For an unanchored pattern, if a match attempt fails at the start of a
2369        newline sequence, and the newline setting is CRLF or ANY, and the next two
2370        characters are CRLF, advance by two characters instead of one.
2373    Version 6.7 04-Jul-06
2374    ---------------------
2376     1. In order to handle tests when input lines are enormously long, pcretest has
2377        been re-factored so that it automatically extends its buffers when
2378        necessary. The code is crude, but this _is_ just a test program. The
2379        default size has been increased from 32K to 50K.
2381     2. The code in pcre_study() was using the value of the re argument before
2382        testing it for NULL. (Of course, in any sensible call of the function, it
2383        won't be NULL.)
2385     3. The memmove() emulation function in pcre_internal.h, which is used on
2386        systems that lack both memmove() and bcopy() - that is, hardly ever -
2387        was missing a "static" storage class specifier.
2389     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2390        containing an extended class (one that cannot be represented by a bitmap
2391        because it contains high-valued characters or Unicode property items, e.g.
2392        [\pZ]). Almost always one would set UTF-8 mode when processing such a
2393        pattern, but PCRE should not loop if you do not (it no longer does).
2394        [Detail: two cases were found: (a) a repeated subpattern containing an
2395        extended class; (b) a recursive reference to a subpattern that followed a
2396        previous extended class. It wasn't skipping over the extended class
2397        correctly when UTF-8 mode was not set.]
2399     5. A negated single-character class was not being recognized as fixed-length
2400        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2401        compile error "lookbehind assertion is not fixed length".
2403     6. The RunPerlTest auxiliary script was showing an unexpected difference
2404        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2405        write a Perl script that can interpret lines of an input file either as
2406        byte characters or as UTF-8, which is what "perltest" was being required to
2407        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2408        can't do is switch easily at run time between having the "use utf8;" pragma
2409        or not. In the end, I fudged it by using the RunPerlTest script to insert
2410        "use utf8;" explicitly for the UTF-8 tests.
2412     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2413        the end of the subject string, contrary to the documentation and to what
2414        Perl does. This was true of both matching functions. Now it matches only at
2415        the start of the subject and immediately after *internal* newlines.
2417     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2418        a pointer to an int instead of a pointer to an unsigned long int. This
2419        caused problems on 64-bit systems.
2421     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2422        instance of the 'standard' template library not being so standard".
2424    10. There was no check on the number of named subpatterns nor the maximum
2425        length of a subpattern name. The product of these values is used to compute
2426        the size of the memory block for a compiled pattern. By supplying a very
2427        long subpattern name and a large number of named subpatterns, the size
2428        computation could be caused to overflow. This is now prevented by limiting
2429        the length of names to 32 characters, and the number of named subpatterns
2430        to 10,000.
2432    11. Subpatterns that are repeated with specific counts have to be replicated in
2433        the compiled pattern. The size of memory for this was computed from the
2434        length of the subpattern and the repeat count. The latter is limited to
2435        65535, but there was no limit on the former, meaning that integer overflow
2436        could in principle occur. The compiled length of a repeated subpattern is
2437        now limited to 30,000 bytes in order to prevent this.
2439    12. Added the optional facility to have named substrings with the same name.
2441    13. Added the ability to use a named substring as a condition, using the
2442        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2443        are numbers (not recommended). Forward references are permitted.
2445    14. Added forward references in named backreferences (if you see what I mean).
2447    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2448        pattern could run off the end of the subject. For example, the pattern
2449        "(?s)(.{1,5})"8 did this with the subject "ab".
2451    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2452        PCRE_CASELESS was set when matching characters that were quantified with ?
2453        or *.
2455    17. A character class other than a single negated character that had a minimum
2456        but no maximum quantifier - for example [ab]{6,} - was not handled
2457        correctly by pce_dfa_exec(). It would match only one character.
2459    18. A valid (though odd) pattern that looked like a POSIX character
2460        class but used an invalid character after [ (for example [[,abc,]]) caused
2461        pcre_compile() to give the error "Failed: internal error: code overflow" or
2462        in some cases to crash with a glibc free() error. This could even happen if
2463        the pattern terminated after [[ but there just happened to be a sequence of
2464        letters, a binary zero, and a closing ] in the memory that followed.
2466    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2467        over the years. Originally (before any Unicode support), just the bottom 8
2468        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2469        output from "man perlunicode" includes this:
2471          The regular expression compiler produces polymorphic opcodes.  That
2472          is, the pattern adapts to the data and automatically switches to
2473          the Unicode character scheme when presented with Unicode data--or
2474          instead uses a traditional byte scheme when presented with byte
2475          data.
2477        Sadly, a wide octal escape does not cause a switch, and in a string with
2478        no other multibyte characters, these octal escapes are treated as before.
2479        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
2480        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2481        Unicode string.
2483        I have not perpetrated such confusion in PCRE. Up till now, it took just
2484        the bottom 8 bits, as in old Perl. I have now made octal escapes with
2485        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2486        translate to the appropriate multibyte character.
2488    29. Applied some refactoring to reduce the number of warnings from Microsoft
2489        and Borland compilers. This has included removing the fudge introduced
2490        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2491        a warning about an unused variable.
2493    21. PCRE has not included VT (character 0x0b) in the set of whitespace
2494        characters since release 4.0, because Perl (from release 5.004) does not.
2495        [Or at least, is documented not to: some releases seem to be in conflict
2496        with the documentation.] However, when a pattern was studied with
2497        pcre_study() and all its branches started with \s, PCRE still included VT
2498        as a possible starting character. Of course, this did no harm; it just
2499        caused an unnecessary match attempt.
2501    22. Removed a now-redundant internal flag bit that recorded the fact that case
2502        dependency changed within the pattern. This was once needed for "required
2503        byte" processing, but is no longer used. This recovers a now-scarce options
2504        bit. Also moved the least significant internal flag bit to the most-
2505        significant bit of the word, which was not previously used (hangover from
2506        the days when it was an int rather than a uint) to free up another bit for
2507        the future.
2509    23. Added support for CRLF line endings as well as CR and LF. As well as the
2510        default being selectable at build time, it can now be changed at runtime
2511        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2512        specify that it is scanning data with non-default line endings.
2514    24. Changed the definition of CXXLINK to make it agree with the definition of
2515        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2517    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2518        recursions. This makes a big different to stack usage for some patterns.
2520    26. If a subpattern containing a named recursion or subroutine reference such
2521        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2522        the space required for the compiled pattern went wrong and gave too small a
2523        value. Depending on the environment, this could lead to "Failed: internal
2524        error: code overflow at offset 49" or "glibc detected double free or
2525        corruption" errors.
2527    27. Applied patches from Google (a) to support the new newline modes and (b) to
2528        advance over multibyte UTF-8 characters in GlobalReplace.
2530    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2531        difference for some implementation of PCRE in some Windows version.
2533    29. Added some extra testing facilities to pcretest:
2535        \q<number>   in a data line sets the "match limit" value
2536        \Q<number>   in a data line sets the "match recursion limt" value
2537        -S <number>  sets the stack size, where <number> is in megabytes
2539        The -S option isn't available for Windows.
2542    Version 6.6 06-Feb-06
2543    ---------------------
2545     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2546        in pcreposix.h. I have copied the definition from pcre.h.
2548     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2549        because pcre.h is no longer a built file.
2551     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2552        not normally included in the compiled code.
2555    Version 6.5 01-Feb-06
2556    ---------------------
2558     1. When using the partial match feature with pcre_dfa_exec(), it was not
2559        anchoring the second and subsequent partial matches at the new starting
2560        point. This could lead to incorrect results. For example, with the pattern
2561        /1234/, partially matching against "123" and then "a4" gave a match.
2563     2. Changes to pcregrep:
2565        (a) All non-match returns from pcre_exec() were being treated as failures
2566            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2567            error message is output. Some extra information is given for the
2568            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2569            probably the only errors that are likely to be caused by users (by
2570            specifying a regex that has nested indefinite repeats, for instance).
2571            If there are more than 20 of these errors, pcregrep is abandoned.
2573        (b) A binary zero was treated as data while matching, but terminated the
2574            output line if it was written out. This has been fixed: binary zeroes
2575            are now no different to any other data bytes.
2577        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2578            used to set a locale for matching. The --locale=xxxx long option has
2579            been added (no short equivalent) to specify a locale explicitly on the
2580            pcregrep command, overriding the environment variables.
2582        (d) When -B was used with -n, some line numbers in the output were one less
2583            than they should have been.
2585        (e) Added the -o (--only-matching) option.
2587        (f) If -A or -C was used with -c (count only), some lines of context were
2588            accidentally printed for the final match.
2590        (g) Added the -H (--with-filename) option.
2592        (h) The combination of options -rh failed to suppress file names for files
2593            that were found from directory arguments.
2595        (i) Added the -D (--devices) and -d (--directories) options.
2597        (j) Added the -F (--fixed-strings) option.
2599        (k) Allow "-" to be used as a file name for -f as well as for a data file.
2601        (l) Added the --colo(u)r option.
2603        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2604            is not present by default.
2606     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2607        items such as (?R) or (?1), when the recursion could match a number of
2608        alternatives. If it matched one of the alternatives, but subsequently,
2609        outside the recursion, there was a failure, the code tried to back up into
2610        the recursion. However, because of the way PCRE is implemented, this is not
2611        possible, and the result was an incorrect result from the match.
2613        In order to prevent this happening, the specification of recursion has
2614        been changed so that all such subpatterns are automatically treated as
2615        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2617     4. I had overlooked the fact that, in some locales, there are characters for
2618        which isalpha() is true but neither isupper() nor islower() are true. In
2619        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2620        and ordfeminine) are like this. This affected the treatment of \w and \W
2621        when they appeared in character classes, but not when they appeared outside
2622        a character class. The bit map for "word" characters is now created
2623        separately from the results of isalnum() instead of just taking it from the
2624        upper, lower, and digit maps. (Plus the underscore character, of course.)
2626     5. The above bug also affected the handling of POSIX character classes such as
2627        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2628        permanent tables. Instead, the bit maps for such a class were previously
2629        created as the appropriate unions of the upper, lower, and digit bitmaps.
2630        Now they are created by subtraction from the [[:word:]] class, which has
2631        its own bitmap.
2633     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2634        It is created by subtracting the vertical space characters (\x09, \x0a,
2635        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2636        subtraction was done in the overall bitmap for a character class, meaning
2637        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2638        be recognized. This bug has been fixed.
2640     7. Patches from the folks at Google:
2642          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2643          real life, but is still worth protecting against".
2645          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2646          regular expressions".
2648          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2649          have it.
2651          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2652          "configure" and the latter not, in order to fix a problem somebody had
2653          with compiling the Arg class on HP-UX.
2655          (e) Improve the error-handling of the C++ wrapper a little bit.
2657          (f) New tests for checking recursion limiting.
2659     8. The pcre_memmove() function, which is used only if the environment does not
2660        have a standard memmove() function (and is therefore rarely compiled),
2661        contained two bugs: (a) use of int instead of size_t, and (b) it was not
2662        returning a result (though PCRE never actually uses the result).
2664     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2665        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2666        returned instead of calling malloc() with an overflowing number that would
2667        most likely cause subsequent chaos.
2669    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2671    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2672        with this option is matched, the nmatch and pmatch options of regexec() are
2673        ignored.
2675    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2676        provided in case anyone wants to the the POSIX interface with UTF-8
2677        strings.
2679    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2680        C++ linking (needed for some HP-UX environments).
2682    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2683        (unused parameter) and in the pcre_printint() function (omitted "default"
2684        switch label when the default is to do nothing).
2686    15. Added some code to make it possible, when PCRE is compiled as a C++
2687        library, to replace subject pointers for pcre_exec() with a smart pointer
2688        class, thus making it possible to process discontinuous strings.
2690    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2691        much the same function. They were added by different people who were trying
2692        to make PCRE easy to compile on non-Unix systems. It has been suggested
2693        that PCRE_EXPORT be abolished now that there is more automatic apparatus
2694        for compiling on Windows systems. I have therefore replaced it with
2695        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2696        defaults to "extern" for C or "extern C" for C++, which works fine on
2697        Unix-like systems. It is now possible to override the value of PCRE_DATA_
2698        SCOPE with something explicit in config.h. In addition:
2700        (a) pcreposix.h still had just "extern" instead of either of these macros;
2701            I have replaced it with PCRE_DATA_SCOPE.
2703        (b) Functions such as _pcre_xclass(), which are internal to the library,
2704            but external in the C sense, all had PCRE_EXPORT in their definitions.
2705            This is apparently wrong for the Windows case, so I have removed it.
2706            (It makes no difference on Unix-like systems.)
2708    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2709        of recursive calls to match(). This is different to MATCH_LIMIT because
2710        that limits the total number of calls to match(), not all of which increase
2711        the depth of recursion. Limiting the recursion depth limits the amount of
2712        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2713        when PCRE is compiled, and changed at run time. A patch from Google adds
2714        this functionality to the C++ interface.
2716    18. Changes to the handling of Unicode character properties:
2718        (a) Updated the table to Unicode 4.1.0.
2720        (b) Recognize characters that are not in the table as "Cn" (undefined).
2722        (c) I revised the way the table is implemented to a much improved format
2723            which includes recognition of ranges. It now supports the ranges that
2724            are defined in UnicodeData.txt, and it also amalgamates other
2725            characters into ranges. This has reduced the number of entries in the
2726            table from around 16,000 to around 3,000, thus reducing its size
2727            considerably. I realized I did not need to use a tree structure after
2728            all - a binary chop search is just as efficient. Having reduced the
2729            number of entries, I extended their size from 6 bytes to 8 bytes to
2730            allow for more data.
2732        (d) Added support for Unicode script names via properties such as \p{Han}.
2734    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2735        matching that character.
2737    20. When matching a repeated Unicode property with a minimum greater than zero,
2738        (for example \pL{2,}), PCRE could look past the end of the subject if it
2739        reached it while seeking the minimum number of characters. This could
2740        happen only if some of the characters were more than one byte long, because
2741        there is a check for at least the minimum number of bytes.
2743    21. Refactored the implementation of \p and \P so as to be more general, to
2744        allow for more different types of property in future. This has changed the
2745        compiled form incompatibly. Anybody with saved compiled patterns that use
2746        \p or \P will have to recompile them.
2748    22. Added "Any" and "L&" to the supported property types.
2750    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2751        but give a compile time error if the value is greater than 0xff.
2753    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2754        accidentally not being installed or uninstalled.
2756    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2757        made were to insert the current release number. This seemed silly, because
2758        it made things harder for people building PCRE on systems that don't run
2759        "configure". I have turned pcre.h into a distributed file, no longer built
2760        by "configure", with the version identification directly included. There is
2761        no longer a pcre.h.in file.
2763        However, this change necessitated a change to the pcre-config script as
2764        well. It is built from pcre-config.in, and one of the substitutions was the
2765        release number. I have updated configure.ac so that ./configure now finds
2766        the release number by grepping pcre.h.
2768    26. Added the ability to run the tests under valgrind.
2771  Version 6.4 05-Sep-05  Version 6.4 05-Sep-05
2772  ---------------------  ---------------------

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