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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 01-May-07  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 the code for calculating the fixed length of lookbehind
11        assertions.
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.
34    Version 8.21 12-Dec-2011
35    ------------------------
37    1.  Updating the JIT compiler.
39    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
40        are added as well.
42    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
43        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
44        calling _pcre_jit_exec. Some extra comments are added.
46    4.  (*MARK) settings inside atomic groups that do not contain any capturing
47        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
48        was introduced by change 18 for 8.20.
50    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
51        ECMA-262 standard.
53    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
54        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
55        This bug was probably introduced by change 9 of 8.13.
57    7.  While fixing 6 above, I noticed that a number of other items were being
58        incorrectly rejected as "not fixed length". This arose partly because newer
59        opcodes had not been added to the fixed-length checking code. I have (a)
60        corrected the bug and added tests for these items, and (b) arranged for an
61        error to occur if an unknown opcode is encountered while checking for fixed
62        length instead of just assuming "not fixed length". The items that were
63        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
64        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
65        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
67    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
68        being incorrectly compiled and would have given unpredicatble results.
70    9.  A possessively repeated subpattern with minimum repeat count greater than
71        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
72        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
73        the first (A) could occur when it should not.
75    10. Add a cast and remove a redundant test from the code.
77    11. JIT should use pcre_malloc/pcre_free for allocation.
79    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
80        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
81        is anything other than /usr, -L is still shown).
83    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
85    14. Perl does not support \N without a following name in a [] class; PCRE now
86        also gives an error.
88    15. If a forward reference was repeated with an upper limit of around 2000,
89        it caused the error "internal error: overran compiling workspace". The
90        maximum number of forward references (including repeats) was limited by the
91        internal workspace, and dependent on the LINK_SIZE. The code has been
92        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
93        the default depends on LINK_SIZE. There is a new upper limit (for safety)
94        of around 200,000 forward references. While doing this, I also speeded up
95        the filling in of repeated forward references.
97    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
98        incorrectly expecting the subject to contain another "a" after the start.
100    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
101        in the match, the SKIP should be ignored. This was not happening; instead
102        the SKIP was being treated as NOMATCH. For patterns such as
103        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
104        tested.
106    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
107        now much more compatible with Perl, in particular in cases where the result
108        is a non-match for a non-anchored pattern. For example, if
109        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
110        "m", where previously it did not return a name. A side effect of this
111        change is that for partial matches, the last encountered mark name is
112        returned, as for non matches. A number of tests that were previously not
113        Perl-compatible have been moved into the Perl-compatible test files. The
114        refactoring has had the pleasing side effect of removing one argument from
115        the match() function, thus reducing its stack requirements.
117    19. If the /S+ option was used in pcretest to study a pattern using JIT,
118        subsequent uses of /S (without +) incorrectly behaved like /S+.
120    21. Retrieve executable code size support for the JIT compiler and fixing
121        some warnings.
123    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
124        not work when the shorter character appeared right at the end of the
125        subject string.
127    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
128        systems.
130    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
131        output it when the /M option is used in pcretest.
133    25. The CheckMan script was not being included in the distribution. Also, added
134        an explicit "perl" to run Perl scripts from the PrepareRelease script
135        because this is reportedly needed in Windows.
137    26. If study data was being save in a file and studying had not found a set of
138        "starts with" bytes for the pattern, the data written to the file (though
139        never used) was taken from uninitialized memory and so caused valgrind to
140        complain.
142    27. Updated RunTest.bat as provided by Sheri Pierce.
144    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
146    29. Computation of memory usage for the table of capturing group names was
147        giving an unnecessarily large value.
150    Version 8.20 21-Oct-2011
151    ------------------------
153    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
154        a POSIX class. After further experiments with Perl, which convinced me that
155        Perl has bugs and confusions, a closing square bracket is no longer allowed
156        in a POSIX name. This bug also affected patterns with classes that started
157        with full stops.
159    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
160        captured substring, but while checking the failing first alternative,
161        substring 1 is temporarily captured. If the output vector supplied to
162        pcre_exec() was not big enough for this capture, the yield of the function
163        was still zero ("insufficient space for captured substrings"). This cannot
164        be totally fixed without adding another stack variable, which seems a lot
165        of expense for a edge case. However, I have improved the situation in cases
166        such as /(a)(b)x|abc/ matched against "abc", where the return code
167        indicates that fewer than the maximum number of slots in the ovector have
168        been set.
170    3.  Related to (2) above: when there are more back references in a pattern than
171        slots in the output vector, pcre_exec() uses temporary memory during
172        matching, and copies in the captures as far as possible afterwards. It was
173        using the entire output vector, but this conflicts with the specification
174        that only 2/3 is used for passing back captured substrings. Now it uses
175        only the first 2/3, for compatibility. This is, of course, another edge
176        case.
178    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
179        main code base, and can be used by building with --enable-jit. When this is
180        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
181        runtime --no-jit option is given.
183    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
184        ovector, the return from the function was zero, implying that there were
185        other matches that did not fit. The correct "exactly full" value is now
186        returned.
188    6.  If a subpattern that was called recursively or as a subroutine contained
189        (*PRUNE) or any other control that caused it to give a non-standard return,
190        invalid errors such as "Error -26 (nested recursion at the same subject
191        position)" or even infinite loops could occur.
193    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
194        computing the minimum length on reaching *ACCEPT, and so ended up with the
195        wrong value of 1 rather than 0. Further investigation indicates that
196        computing a minimum subject length in the presence of *ACCEPT is difficult
197        (think back references, subroutine calls), and so I have changed the code
198        so that no minimum is registered for a pattern that contains *ACCEPT.
200    8.  If (*THEN) was present in the first (true) branch of a conditional group,
201        it was not handled as intended. [But see 16 below.]
203    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
204        Sheri Pierce.
206    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
207        the first byte in a match must be "a".
209    11. Change 17 for 8.13 increased the recursion depth for patterns like
210        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
211        pattern contains any instances of (*THEN). If it does not, the old
212        optimizations are restored. It would be nice to do this on a per-group
213        basis, but at the moment that is not feasible.
215    12. In some environments, the output of pcretest -C is CRLF terminated. This
216        broke RunTest's code that checks for the link size. A single white space
217        character after the value is now allowed for.
219    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
220        For "fr", it uses the Windows-specific input and output files.
222    14. If (*THEN) appeared in a group that was called recursively or as a
223        subroutine, it did not work as intended. [But see next item.]
225    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
226        pattern fragments (but not containing any | characters). If A and B are
227        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
228        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
229        D. In other words, Perl considers parentheses that do not contain any |
230        characters to be part of a surrounding alternative, whereas PCRE was
231        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
232        differently. PCRE now behaves in the same way as Perl, except in the case
233        of subroutine/recursion calls such as (?1) which have in any case always
234        been different (but PCRE had them first :-).
236    16. Related to 15 above: Perl does not treat the | in a conditional group as
237        creating alternatives. Such a group is treated in the same way as an
238        ordinary group without any | characters when processing (*THEN). PCRE has
239        been changed to match Perl's behaviour.
241    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
242        RunGrepTest script failed.
244    18. Change 22 for version 13 caused atomic groups to use more stack. This is
245        inevitable for groups that contain captures, but it can lead to a lot of
246        stack use in large patterns. The old behaviour has been restored for atomic
247        groups that do not contain any capturing parentheses.
249    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
250        suppress the check for a minimum subject length at run time. (If it was
251        given to pcre_exec() or pcre_dfa_exec() it did work.)
253    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
254        fail to work when decoding hex characters in data strings in EBCDIC
255        environments.
257    21. It appears that in at least one Mac OS environment, the isxdigit() function
258        is implemented as a macro that evaluates to its argument more than once,
259        contravening the C 90 Standard (I haven't checked a later standard). There
260        was an instance in pcretest which caused it to go wrong when processing
261        \x{...} escapes in subject strings. The has been rewritten to avoid using
262        things like p++ in the argument of isxdigit().
265    Version 8.13 16-Aug-2011
266    ------------------------
268    1.  The Unicode data tables have been updated to Unicode 6.0.0.
270    2.  Two minor typos in pcre_internal.h have been fixed.
272    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
273        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
274        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
276    4.  There were a number of related bugs in the code for matching backrefences
277        caselessly in UTF-8 mode when codes for the characters concerned were
278        different numbers of bytes. For example, U+023A and U+2C65 are an upper
279        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
280        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
281        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
282        2-byte code at the end of the subject (it thought there wasn't enough data
283        left).
285    5.  Comprehensive information about what went wrong is now returned by
286        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
287        as the output vector has at least 2 elements. The offset of the start of
288        the failing character and a reason code are placed in the vector.
290    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
291        now returned is for the first byte of the failing character, instead of the
292        last byte inspected. This is an incompatible change, but I hope it is small
293        enough not to be a problem. It makes the returned offset consistent with
294        pcre_exec() and pcre_dfa_exec().
296    7.  pcretest now gives a text phrase as well as the error number when
297        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
298        failure, the offset and reason code are output.
300    8.  When \R was used with a maximizing quantifier it failed to skip backwards
301        over a \r\n pair if the subsequent match failed. Instead, it just skipped
302        back over a single character (\n). This seems wrong (because it treated the
303        two characters as a single entity when going forwards), conflicts with the
304        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
305        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
306        has been changed.
308    9.  Some internal refactoring has changed the processing so that the handling
309        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
310        time (the PCRE_DOTALL option was changed this way some time ago: version
311        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
312        which was always a bit of a fudge. It also means that there is one less
313        argument for the match() function, which reduces its stack requirements
314        slightly. This change also fixes an incompatibility with Perl: the pattern
315        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
317    10. More internal refactoring has drastically reduced the number of recursive
318        calls to match() for possessively repeated groups such as (abc)++ when
319        using pcre_exec().
321    11. While implementing 10, a number of bugs in the handling of groups were
322        discovered and fixed:
324        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
325        (a|)*(?1) gave a compile-time internal error.
326        ((a|)+)+  did not notice that the outer group could match an empty string.
327        (^a|^)+   was not marked as anchored.
328        (.*a|.*)+ was not marked as matching at start or after a newline.
330    12. Yet more internal refactoring has removed another argument from the match()
331        function. Special calls to this function are now indicated by setting a
332        value in a variable in the "match data" data block.
334    13. Be more explicit in pcre_study() instead of relying on "default" for
335        opcodes that mean there is no starting character; this means that when new
336        ones are added and accidentally left out of pcre_study(), testing should
337        pick them up.
339    14. The -s option of pcretest has been documented for ages as being an old
340        synonym of -m (show memory usage). I have changed it to mean "force study
341        for every regex", that is, assume /S for every regex. This is similar to -i
342        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
343        using it. It makes it easier to run collections of tests with and without
344        study enabled, and thereby test pcre_study() more easily. All the standard
345        tests are now run with and without -s (but some patterns can be marked as
346        "never study" - see 20 below).
348    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
349        restoration of the capturing data to the outer values was not happening
350        correctly.
352    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
353        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
354        pattern had matched an empty string, and so incorrectly returned a no
355        match.
357    17. There was optimizing code for the last branch of non-capturing parentheses,
358        and also for the obeyed branch of a conditional subexpression, which used
359        tail recursion to cut down on stack usage. Unfortunately, now that there is
360        the possibility of (*THEN) occurring in these branches, tail recursion is
361        no longer possible because the return has to be checked for (*THEN). These
362        two optimizations have therefore been removed. [But see 8.20/11 above.]
364    18. If a pattern containing \R was studied, it was assumed that \R always
365        matched two bytes, thus causing the minimum subject length to be
366        incorrectly computed because \R can also match just one byte.
368    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
369        was incorrectly computed.
371    20. If /S is present twice on a test pattern in pcretest input, it now
372        *disables* studying, thereby overriding the use of -s on the command line
373        (see 14 above). This is necessary for one or two tests to keep the output
374        identical in both cases.
376    21. When (*ACCEPT) was used in an assertion that matched an empty string and
377        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
379    22. When an atomic group that contained a capturing parenthesis was
380        successfully matched, but the branch in which it appeared failed, the
381        capturing was not being forgotten if a higher numbered group was later
382        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
383        group 1 to "a", when in fact it should be unset. This applied to multi-
384        branched capturing and non-capturing groups, repeated or not, and also to
385        positive assertions (capturing in negative assertions does not happen
386        in PCRE) and also to nested atomic groups.
388    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
389        subject after a captured substring, to make it easier to tell which of a
390        number of identical substrings has been captured.
392    24. The way atomic groups are processed by pcre_exec() has been changed so that
393        if they are repeated, backtracking one repetition now resets captured
394        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
395        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
396        "aaa". Previously, it would have been "a". As part of this code
397        refactoring, the way recursive calls are handled has also been changed.
399    25. If an assertion condition captured any substrings, they were not passed
400        back unless some other capturing happened later. For example, if
401        (?(?=(a))a) was matched against "a", no capturing was returned.
403    26. When studying a pattern that contained subroutine calls or assertions,
404        the code for finding the minimum length of a possible match was handling
405        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
406        group 1 called group 2 while simultaneously a separate group 2 called group
407        1). A stack overflow occurred in this case. I have fixed this by limiting
408        the recursion depth to 10.
410    27. Updated RunTest.bat in the distribution to the version supplied by Tom
411        Fortmann. This supports explicit test numbers on the command line, and has
412        argument validation and error reporting.
414    28. An instance of \X with an unlimited repeat could fail if at any point the
415        first character it looked at was a mark character.
417    29. Some minor code refactoring concerning Unicode properties and scripts
418        should reduce the stack requirement of match() slightly.
420    30. Added the '=' option to pcretest to check the setting of unused capturing
421        slots at the end of the pattern, which are documented as being -1, but are
422        not included in the return count.
424    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
425        compiled something random. Now it gives a compile-time error (as does
426        Perl).
428    32. A *MARK encountered during the processing of a positive assertion is now
429        recorded and passed back (compatible with Perl).
431    33. If --only-matching or --colour was set on a pcregrep call whose pattern
432        had alternative anchored branches, the search for a second match in a line
433        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
434        matched the line "0102" twice. The same bug affected patterns that started
435        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
436        twice.
438    34. Previously, PCRE did not allow quantification of assertions. However, Perl
439        does, and because of capturing effects, quantifying parenthesized
440        assertions may at times be useful. Quantifiers are now allowed for
441        parenthesized assertions.
443    35. A minor code tidy in pcre_compile() when checking options for \R usage.
445    36. \g was being checked for fancy things in a character class, when it should
446        just be a literal "g".
448    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
449        appearance of a nested POSIX class supersedes an apparent external class.
450        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
451        unescaped square brackets may also appear as part of class names. For
452        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
453        more like Perl. (But see 8.20/1 above.)
455    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
456        was because it thought it was \N{name}, which is not supported).
458    39. Add minix to OS list not supporting the -S option in pcretest.
460    40. PCRE tries to detect cases of infinite recursion at compile time, but it
461        cannot analyze patterns in sufficient detail to catch mutual recursions
462        such as ((?1))((?2)). There is now a runtime test that gives an error if a
463        subgroup is called recursively as a subpattern for a second time at the
464        same position in the subject string. In previous releases this might have
465        been caught by the recursion limit, or it might have run out of stack.
467    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
468        happen only once. PCRE was, however incorrectly giving a compile time error
469        "recursive call could loop indefinitely" because it cannot analyze the
470        pattern in sufficient detail. The compile time test no longer happens when
471        PCRE is compiling a conditional subpattern, but actual runaway loops are
472        now caught at runtime (see 40 above).
474    42. It seems that Perl allows any characters other than a closing parenthesis
475        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
476        has been changed to be the same.
478    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
479        as not to get warnings when autogen.sh is called. Also changed
480        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
482    44. To help people who use pcregrep to scan files containing exceedingly long
483        lines, the following changes have been made:
485        (a) The default value of the buffer size parameter has been increased from
486            8K to 20K. (The actual buffer used is three times this size.)
488        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
489            PCRE is built.
491        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
492            to be set at run time.
494        (d) Numerical values in pcregrep options can be followed by K or M, for
495            example --buffer-size=50K.
497        (e) If a line being scanned overflows pcregrep's buffer, an error is now
498            given and the return code is set to 2.
500    45. Add a pointer to the latest mark to the callout data block.
502    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
503        partial match of an empty string instead of no match. This was specific to
504        the use of ".".
506    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
507        complete match instead of a partial match. This bug was dependent on both
508        the PCRE_UTF8 and PCRE_DOTALL options being set.
510    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
511        starting byte set, because \b was not being ignored.
514    Version 8.12 15-Jan-2011
515    ------------------------
517    1.  Fixed some typos in the markup of the man pages, and wrote a script that
518        checks for such things as part of the documentation building process.
520    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
521        --match-limit and --recursion-limit options (added for 8.11). In
522        particular, this made one of the standard tests fail. (The integer value
523        went into the wrong half of a long int.)
525    3.  If the --colour option was given to pcregrep with -v (invert match), it
526        did strange things, either producing crazy output, or crashing. It should,
527        of course, ignore a request for colour when reporting lines that do not
528        match.
530    4.  Another pcregrep bug caused similar problems if --colour was specified with
531        -M (multiline) and the pattern match finished with a line ending.
533    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
534        matched in multiline mode, the following line was shown as part of the
535        match. This seems wrong, so I have changed it.
537    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
538        the check for further matches in the same line (so they could be coloured)
539        to overrun the end of the current line. If another match was found, it was
540        incorrectly shown (and then shown again when found in the next line).
542    7.  If pcregrep was compiled under Windows, there was a reference to the
543        function pcregrep_exit() before it was defined. I am assuming this was
544        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
545        reported by a user. I've moved the definition above the reference.
548    Version 8.11 10-Dec-2010
549    ------------------------
551    1.  (*THEN) was not working properly if there were untried alternatives prior
552        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
553        backtracked to try for "b" instead of moving to the next alternative branch
554        at the same level (in this case, to look for "c"). The Perl documentation
555        is clear that when (*THEN) is backtracked onto, it goes to the "next
556        alternative in the innermost enclosing group".
558    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
559        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
560        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
561        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
562        (*THEN).
564    3.  If \s appeared in a character class, it removed the VT character from
565        the class, even if it had been included by some previous item, for example
566        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
567        of \s, but is part of the POSIX "space" class.)
569    4.  A partial match never returns an empty string (because you can always
570        match an empty string at the end of the subject); however the checking for
571        an empty string was starting at the "start of match" point. This has been
572        changed to the "earliest inspected character" point, because the returned
573        data for a partial match starts at this character. This means that, for
574        example, /(?<=abc)def/ gives a partial match for the subject "abc"
575        (previously it gave "no match").
577    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
578        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
579        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
580        has an implication that the given string is incomplete (because a partial
581        match is preferred over a full match). For this reason, these items now
582        give a partial match in this situation. [Aside: previously, the one case
583        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
584        match rather than a full match, which was wrong by the old rules, but is
585        now correct.]
587    6.  There was a bug in the handling of #-introduced comments, recognized when
588        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
589        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
590        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
591        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
592        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
593        places in pcre_compile().
595    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
596        comments when looking ahead for named forward references to subpatterns,
597        the only newline sequence it recognized was NL. It now handles newlines
598        according to the set newline convention.
600    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
601        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
602        cater for a lack of strerror(). These oversights have been fixed.
604    9.  Added --match-limit and --recursion-limit to pcregrep.
606    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
608    11. When the -o option was used, pcregrep was setting a return code of 1, even
609        when matches were found, and --line-buffered was not being honoured.
611    12. Added an optional parentheses number to the -o and --only-matching options
612        of pcregrep.
614    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
615        can match an empty string. The code to do it in pcretest and pcredemo
616        needed fixing:
618        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
619            only one byte after an empty string match just before CRLF (this case
620            just got forgotten; "any" and "anycrlf" were OK).
622        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
623            mode when an empty string match preceded an ASCII character followed by
624            a non-ASCII character. (The code for advancing by one character rather
625            than one byte was nonsense.)
627        (c) The pcredemo.c sample program did not have any code at all to handle
628            the cases when CRLF is a valid newline sequence.
630    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
631        as a starting offset was within the subject string. There is now a new
632        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
633        negative or greater than the length of the string. In order to test this,
634        pcretest is extended to allow the setting of negative starting offsets.
636    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
637        starting offset points to the beginning of a UTF-8 character was
638        unnecessarily clumsy. I tidied it up.
640    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
641        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
643    17. Nobody had reported that the --include_dir option, which was added in
644        release 7.7 should have been called --include-dir (hyphen, not underscore)
645        for compatibility with GNU grep. I have changed it to --include-dir, but
646        left --include_dir as an undocumented synonym, and the same for
647        --exclude-dir, though that is not available in GNU grep, at least as of
648        release 2.5.4.
650    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
651        characters from a string of bytes) have been redefined so as not to use
652        loops, in order to improve performance in some environments. At the same
653        time, I abstracted some of the common code into auxiliary macros to save
654        repetition (this should not affect the compiled code).
656    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
657        compile-time error is now given if \c is not followed by an ASCII
658        character, that is, a byte less than 128. (In EBCDIC mode, the code is
659        different, and any byte value is allowed.)
661    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
662        START_OPTIMIZE option, which is now allowed at compile time - but just
663        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
664        to pcregrep and other applications that have no direct access to PCRE
665        options. The new /Y option in pcretest sets this option when calling
666        pcre_compile().
668    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
669        back references. Groups containing recursive back references were forced to
670        be atomic by that change, but in the case of named groups, the amount of
671        memory required was incorrectly computed, leading to "Failed: internal
672        error: code overflow". This has been fixed.
674    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
675        pcretest.c, to avoid build problems in some Borland environments.
678    Version 8.10 25-Jun-2010
679    ------------------------
681    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
682        THEN.
684    2.  (*ACCEPT) was not working when inside an atomic group.
686    3.  Inside a character class, \B is treated as a literal by default, but
687        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
688        causes the error). The code is unchanged, but I tidied the documentation.
690    4.  Inside a character class, PCRE always treated \R and \X as literals,
691        whereas Perl faults them if its -w option is set. I have changed PCRE so
692        that it faults them when PCRE_EXTRA is set.
694    5.  Added support for \N, which always matches any character other than
695        newline. (It is the same as "." when PCRE_DOTALL is not set.)
697    6.  When compiling pcregrep with newer versions of gcc which may have
698        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
699        declared with attribute warn_unused_result" were given. Just casting the
700        result to (void) does not stop the warnings; a more elaborate fudge is
701        needed. I've used a macro to implement this.
703    7.  Minor change to pcretest.c to avoid a compiler warning.
705    8.  Added four artifical Unicode properties to help with an option to make
706        \s etc use properties (see next item). The new properties are: Xan
707        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
709    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
710        use Unicode properties. (*UCP) at the start of a pattern can be used to set
711        this option. Modified pcretest to add /W to test this facility. Added
712        REG_UCP to make it available via the POSIX interface.
714    10. Added --line-buffered to pcregrep.
716    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
717        studied, and the match started with a letter with a code point greater than
718        127 whose first byte was different to the first byte of the other case of
719        the letter, the other case of this starting letter was not recognized
720        (#976).
722    12. If a pattern that was studied started with a repeated Unicode property
723        test, for example, \p{Nd}+, there was the theoretical possibility of
724        setting up an incorrect bitmap of starting bytes, but fortunately it could
725        not have actually happened in practice until change 8 above was made (it
726        added property types that matched character-matching opcodes).
728    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
729        possible starting bytes for non-anchored patterns.
731    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
732        \R, and also a number of cases that involve Unicode properties, both
733        explicit and implicit when PCRE_UCP is set.
735    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
736        input, it could crash or give wrong results if characters with values
737        greater than 0xc0 were present in the subject string. (Detail: it assumed
738        UTF-8 input when processing these items.)
740    16. Added a lot of (int) casts to avoid compiler warnings in systems where
741        size_t is 64-bit (#991).
743    17. Added a check for running out of memory when PCRE is compiled with
744        --disable-stack-for-recursion (#990).
746    18. If the last data line in a file for pcretest does not have a newline on
747        the end, a newline was missing in the output.
749    19. The default pcre_chartables.c file recognizes only ASCII characters (values
750        less than 128) in its various bitmaps. However, there is a facility for
751        generating tables according to the current locale when PCRE is compiled. It
752        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
753        characters, are recognized by isspace() and therefore were getting set in
754        these tables, and indeed these tables seem to approximate to ISO 8859. This
755        caused a problem in UTF-8 mode when pcre_study() was used to create a list
756        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
757        which of course cannot start UTF-8 characters. I have changed the code so
758        that only real ASCII characters (less than 128) and the correct starting
759        bytes for UTF-8 encodings are set for characters greater than 127 when in
760        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
761        altogether.)
763    20. Added the /T option to pcretest so as to be able to run tests with non-
764        standard character tables, thus making it possible to include the tests
765        used for 19 above in the standard set of tests.
767    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
768        reference to a subpattern the other side of a comment that contains an
769        opening parenthesis caused either an internal compiling error, or a
770        reference to the wrong subpattern.
773    Version 8.02 19-Mar-2010
774    ------------------------
776    1.  The Unicode data tables have been updated to Unicode 5.2.0.
778    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
779        configured.
781    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
782        original author of that file, following a query about its status.
784    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
785        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
787    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
788        quantifier applied to a forward-referencing subroutine call, could compile
789        incorrect code or give the error "internal error: previously-checked
790        referenced subpattern not found".
792    6.  Both MS Visual Studio and Symbian OS have problems with initializing
793        variables to point to external functions. For these systems, therefore,
794        pcre_malloc etc. are now initialized to local functions that call the
795        relevant global functions.
797    7.  There were two entries missing in the vectors called coptable and poptable
798        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
799        I've fixed the data, and added a kludgy way of testing at compile time that
800        the lengths are correct (equal to the number of opcodes).
802    8.  Following on from 7, I added a similar kludge to check the length of the
803        eint vector in pcreposix.c.
805    9.  Error texts for pcre_compile() are held as one long string to avoid too
806        much relocation at load time. To find a text, the string is searched,
807        counting zeros. There was no check for running off the end of the string,
808        which could happen if a new error number was added without updating the
809        string.
811    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
813    11. \K was not working if it appeared in an atomic group or in a group that
814        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
815        \K is "not well defined" if used in an assertion. PCRE now accepts it if
816        the assertion is positive, but not if it is negative.
818    12. Change 11 fortuitously reduced the size of the stack frame used in the
819        "match()" function of pcre_exec.c by one pointer. Forthcoming
820        implementation of support for (*MARK) will need an extra pointer on the
821        stack; I have reserved it now, so that the stack frame size does not
822        decrease.
824    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
825        item in branch that calls a recursion is a subroutine call - as in the
826        second branch in the above example - was incorrectly given the compile-
827        time error "recursive call could loop indefinitely" because pcre_compile()
828        was not correctly checking the subroutine for matching a non-empty string.
830    14. The checks for overrunning compiling workspace could trigger after an
831        overrun had occurred. This is a "should never occur" error, but it can be
832        triggered by pathological patterns such as hundreds of nested parentheses.
833        The checks now trigger 100 bytes before the end of the workspace.
835    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
838    Version 8.01 19-Jan-2010
839    ------------------------
841    1.  If a pattern contained a conditional subpattern with only one branch (in
842        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
843        computed the wrong minimum data length (which is of course zero for such
844        subpatterns). This could cause incorrect "no match" results.
846    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
847        the pattern is reset in the first branch, pcre_compile() failed with
848        "internal error: code overflow at offset...". This happened only when
849        the reset was to the original external option setting. (An optimization
850        abstracts leading options settings into an external setting, which was the
851        cause of this.)
853    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
854        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
855        assertion pattern did not match (meaning that the assertion was true), it
856        was incorrectly treated as false if the SKIP had been reached during the
857        matching. This also applied to assertions used as conditions.
859    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
860        assertion subpattern, including such a pattern used as a condition,
861        unpredictable results occurred, instead of the error return
864    5.  The C++ GlobalReplace function was not working like Perl for the special
865        situation when an empty string is matched. It now does the fancy magic
866        stuff that is necessary.
868    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
869        removed. (These were left over from very, very early versions of PCRE.)
871    7.  Some cosmetic changes to the code to make life easier when compiling it
872        as part of something else:
874        (a) Change DEBUG to PCRE_DEBUG.
876        (b) In pcre_compile(), rename the member of the "branch_chain" structure
877            called "current" as "current_branch", to prevent a collision with the
878            Linux macro when compiled as a kernel module.
880        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
881            prevent a collision with the Linux macro when compiled as a kernel
882            module.
884    8.  In pcre_compile() there are some checks for integer overflows that used to
885        cast potentially large values to (double). This has been changed to that
886        when building, a check for int64_t is made, and if it is found, it is used
887        instead, thus avoiding the use of floating point arithmetic. (There is no
888        other use of FP in PCRE.) If int64_t is not found, the fallback is to
889        double.
891    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
892        2005 (difference between two addresses compared to an unsigned value).
894    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
895        custom one, because of the following reported problem in Windows:
897          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
898              under Win32.
899          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
900              therefore missing the function definition.
901          - The compiler thus generates a "C" signature for the test function.
902          - The linker fails to find the "C" function.
903          - PCRE fails to configure if asked to do so against libbz2.
905    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
906        messages were output:
908          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
909          rerunning libtoolize, to keep the correct libtool macros in-tree.
910          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
912        I have done both of these things.
914    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
915        most of the time, it *can* run out if it is given a pattern that contains a
916        runaway infinite recursion. I updated the discussion in the pcrestack man
917        page.
919    13. Now that we have gone to the x.xx style of version numbers, the minor
920        version may start with zero. Using 08 or 09 is a bad idea because users
921        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
922        interpreted as invalid octal numbers. I've updated the previous comment in
923        configure.ac, and also added a check that gives an error if 08 or 09 are
924        used.
926    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
927        causing partial matching to fail when the end of the subject matched \W
928        in a UTF-8 pattern where \W was quantified with a minimum of 3.
930    15. There were some discrepancies between the declarations in pcre_internal.h
931        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
932        their definitions. The declarations used "const uschar *" and the
933        definitions used USPTR. Even though USPTR is normally defined as "const
934        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
935        reported that: "This difference in casting confuses some C++ compilers, for
936        example, SunCC recognizes above declarations as different functions and
937        generates broken code for hbpcre." I have changed the declarations to use
938        USPTR.
940    16. GNU libtool is named differently on some systems. The autogen.sh script now
941        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
942        (FreeBSD).
944    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
945        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
946        comment: "Figure out how to create a longlong from a string: strtoll and
947        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
948        instance, but it only takes 2 args instead of 3!"
950    18. A subtle bug concerned with back references has been fixed by a change of
951        specification, with a corresponding code fix. A pattern such as
952        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
953        refers, was giving matches when it shouldn't. For example, xa=xaaa would
954        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
955        same bug. Such groups have to be quantified to be useful, or contained
956        inside another quantified group. (If there's no repetition, the reference
957        can never match.) The problem arises because, having left the group and
958        moved on to the rest of the pattern, a later failure that backtracks into
959        the group uses the captured value from the final iteration of the group
960        rather than the correct earlier one. I have fixed this in PCRE by forcing
961        any group that contains a reference to itself to be an atomic group; that
962        is, there cannot be any backtracking into it once it has completed. This is
963        similar to recursive and subroutine calls.
966    Version 8.00 19-Oct-09
967    ----------------------
969    1.  The table for translating pcre_compile() error codes into POSIX error codes
970        was out-of-date, and there was no check on the pcre_compile() error code
971        being within the table. This could lead to an OK return being given in
972        error.
974    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
975        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
976        in a Windows environment.
978    3.  The pcregrep --count option prints the count for each file even when it is
979        zero, as does GNU grep. However, pcregrep was also printing all files when
980        --files-with-matches was added. Now, when both options are given, it prints
981        counts only for those files that have at least one match. (GNU grep just
982        prints the file name in this circumstance, but including the count seems
983        more useful - otherwise, why use --count?) Also ensured that the
984        combination -clh just lists non-zero counts, with no names.
986    4.  The long form of the pcregrep -F option was incorrectly implemented as
987        --fixed_strings instead of --fixed-strings. This is an incompatible change,
988        but it seems right to fix it, and I didn't think it was worth preserving
989        the old behaviour.
991    5.  The command line items --regex=pattern and --regexp=pattern were not
992        recognized by pcregrep, which required --regex pattern or --regexp pattern
993        (with a space rather than an '='). The man page documented the '=' forms,
994        which are compatible with GNU grep; these now work.
996    6.  No libpcreposix.pc file was created for pkg-config; there was just
997        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
999    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1000        when UCP support is not needed, by modifying the Python script that
1001        generates it from Unicode data files. This should not matter if the module
1002        is correctly used as a library, but I received one complaint about 50K of
1003        unwanted data. My guess is that the person linked everything into his
1004        program rather than using a library. Anyway, it does no harm.
1006    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1007        was a minimum greater than 1 for a wide character in a possessive
1008        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1009        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1010        character. Chaos in the form of incorrect output or a compiling loop could
1011        result.
1013    9.  The restrictions on what a pattern can contain when partial matching is
1014        requested for pcre_exec() have been removed. All patterns can now be
1015        partially matched by this function. In addition, if there are at least two
1016        slots in the offset vector, the offset of the earliest inspected character
1017        for the match and the offset of the end of the subject are set in them when
1018        PCRE_ERROR_PARTIAL is returned.
1020    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1021        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1022        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1023        and may be more useful for multi-segment matching.
1025    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1026        used to be given if ever the end of the subject was reached; now it is
1027        given only if matching could not proceed because another character was
1028        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1029        string "Z", which now yields "no match" instead of "partial match". In the
1030        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1031        final character ended with (*FAIL).
1033    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1034        if the pattern had a "must contain" character that was already found in the
1035        earlier partial match, unless partial matching was again requested. For
1036        example, with the pattern /dog.(body)?/, the "must contain" character is
1037        "g". If the first part-match was for the string "dog", restarting with
1038        "sbody" failed. This bug has been fixed.
1040    13. The string returned by pcre_dfa_exec() after a partial match has been
1041        changed so that it starts at the first inspected character rather than the
1042        first character of the match. This makes a difference only if the pattern
1043        starts with a lookbehind assertion or \b or \B (\K is not supported by
1044        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1045        matching functions compatible, and I think it's the right thing to do.
1047    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1048        so that the demonstration program is easily available in environments where
1049        PCRE has not been installed from source.
1051    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1052        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1053        library.
1055    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1056        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1057        is not the first non-POSIX option to be added. Clearly some people find
1058        these options useful.
1060    17. If a caller to the POSIX matching function regexec() passes a non-zero
1061        value for nmatch with a NULL value for pmatch, the value of
1062        nmatch is forced to zero.
1064    18. RunGrepTest did not have a test for the availability of the -u option of
1065        the diff command, as RunTest does. It now checks in the same way as
1066        RunTest, and also checks for the -b option.
1068    19. If an odd number of negated classes containing just a single character
1069        interposed, within parentheses, between a forward reference to a named
1070        subpattern and the definition of the subpattern, compilation crashed with
1071        an internal error, complaining that it could not find the referenced
1072        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1073        [The bug was that it was starting one character too far in when skipping
1074        over the character class, thus treating the ] as data rather than
1075        terminating the class. This meant it could skip too much.]
1077    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1078        /g option in pcretest when the pattern contains \K, which makes it possible
1079        to have an empty string match not at the start, even when the pattern is
1080        anchored. Updated pcretest and pcredemo to use this option.
1082    21. If the maximum number of capturing subpatterns in a recursion was greater
1083        than the maximum at the outer level, the higher number was returned, but
1084        with unset values at the outer level. The correct (outer level) value is
1085        now given.
1087    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1088        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1089        make it do so. The string so far is captured, making this feature
1090        compatible with Perl.
1092    23. The tests have been re-organized, adding tests 11 and 12, to make it
1093        possible to check the Perl 5.10 features against Perl 5.10.
1095    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1096        pattern matches a fixed length string. PCRE did not allow this; now it
1097        does. Neither allows recursion.
1099    25. I finally figured out how to implement a request to provide the minimum
1100        length of subject string that was needed in order to match a given pattern.
1101        (It was back references and recursion that I had previously got hung up
1102        on.) This code has now been added to pcre_study(); it finds a lower bound
1103        to the length of subject needed. It is not necessarily the greatest lower
1104        bound, but using it to avoid searching strings that are too short does give
1105        some useful speed-ups. The value is available to calling programs via
1106        pcre_fullinfo().
1108    26. While implementing 25, I discovered to my embarrassment that pcretest had
1109        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1110        study optimizations had never been tested with that matching function.
1111        Oops. What is worse, even when it was passed study data, there was a bug in
1112        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1113        were also very few tests of studied patterns with pcre_dfa_exec().
1115    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1116        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1117        on the other side of the coin, they are no longer allowed to have different
1118        names, because these cannot be distinguished in PCRE, and this has caused
1119        confusion. (This is a difference from Perl.)
1121    28. When duplicate subpattern names are present (necessarily with different
1122        numbers, as required by 27 above), and a test is made by name in a
1123        conditional pattern, either for a subpattern having been matched, or for
1124        recursion in such a pattern, all the associated numbered subpatterns are
1125        tested, and the overall condition is true if the condition is true for any
1126        one of them. This is the way Perl works, and is also more like the way
1127        testing by number works.
1130    Version 7.9 11-Apr-09
1131    ---------------------
1133    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1134        (pcretest), all targets were linked against these libraries. This included
1135        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1136        libraries. This caused unwanted dependencies to be created. This problem
1137        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1138        pcretest is linked with readline.
1140    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1141        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1142        moved outside it again, because FALSE and TRUE are already defined in AIX,
1143        but BOOL is not.
1145    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1146        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1148    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1149        hyphens) following file names and line numbers when outputting matching
1150        lines. This is not true; no spaces are inserted. I have also clarified the
1151        wording for the --colour (or --color) option.
1153    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1154        was not coloured; this is different to GNU grep, so I have changed it to be
1155        the same.
1157    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1158        each matching line was coloured. Now it goes on to look for further matches
1159        of any of the test patterns, which is the same behaviour as GNU grep.
1161    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1162        doesn't make sense to accept an empty string match in pcregrep, so I have
1163        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1164        seems to be how GNU grep behaves.
1166    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1167        start or after a newline", because the conditional assertion was not being
1168        correctly handled. The rule now is that both the assertion and what follows
1169        in the first alternative must satisfy the test.
1171    9.  If auto-callout was enabled in a pattern with a conditional group whose
1172        condition was an assertion, PCRE could crash during matching, both with
1173        pcre_exec() and pcre_dfa_exec().
1175    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1176        used for matching.
1178    11. Unicode property support in character classes was not working for
1179        characters (bytes) greater than 127 when not in UTF-8 mode.
1181    12. Added the -M command line option to pcretest.
1183    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1185    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1187    16. Added comments and documentation about mis-use of no_arg in the C++
1188        wrapper.
1190    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1191        from Martin Jerabek that uses macro names for all relevant character and
1192        string constants.
1194    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1195        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1196        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1197        these, but not everybody uses configure.
1199    19. A conditional group that had only one branch was not being correctly
1200        recognized as an item that could match an empty string. This meant that an
1201        enclosing group might also not be so recognized, causing infinite looping
1202        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1203        with the subject "ab", where knowledge that the repeated group can match
1204        nothing is needed in order to break the loop.
1206    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1207        exec(), but without supplying a callout function, matching went wrong.
1209    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1210        leak if the size of the offset vector was greater than 30. When the vector
1211        is smaller, the saved offsets during recursion go onto a local stack
1212        vector, but for larger vectors malloc() is used. It was failing to free
1213        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1214        error, in fact).
1216    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1217        heapframe that is used only when UTF-8 support is enabled. This caused no
1218        problem, but was untidy.
1220    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1221        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1222        included within another project.
1224    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1225        slightly modified by me:
1227          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1228              not building pcregrep.
1230          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1231              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1233    25. Forward references, both numeric and by name, in patterns that made use of
1234        duplicate group numbers, could behave incorrectly or give incorrect errors,
1235        because when scanning forward to find the reference group, PCRE was not
1236        taking into account the duplicate group numbers. A pattern such as
1237        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1239    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1240        the feature of a custom pointer more persuasive (as requested by a user).
1242    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1243        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1244        pre-defined.
1246    28. Added support for (*UTF8) at the start of a pattern.
1248    29. Arrange for flags added by the "release type" setting in CMake to be shown
1249        in the configuration summary.
1252    Version 7.8 05-Sep-08
1253    ---------------------
1255    1.  Replaced UCP searching code with optimized version as implemented for Ad
1256        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1257        stage table and inline lookup instead of a function, giving speed ups of 2
1258        to 5 times on some simple patterns that I tested. Permission was given to
1259        distribute the MultiStage2.py script that generates the tables (it's not in
1260        the tarball, but is in the Subversion repository).
1262    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1263        scripts.
1265    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1266        a group with a zero qualifier. The result of the study could be incorrect,
1267        or the function might crash, depending on the pattern.
1269    4.  Caseless matching was not working for non-ASCII characters in back
1270        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1271        It now works when Unicode Property Support is available.
1273    5.  In pcretest, an escape such as \x{de} in the data was always generating
1274        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1275        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1276        truncation.
1278    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1280    7.  Added two (int) casts to pcregrep when printing the difference of two
1281        pointers, in case they are 64-bit values.
1283    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1284        test 2 if it fails.
1286    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1287        and a #define of that name to empty if it is not externally set. This is to
1288        allow users of MSVC to set it if necessary.
1290    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1291        the convenience functions in the pcre_get.c source file.
1293    11. An option change at the start of a pattern that had top-level alternatives
1294        could cause overwriting and/or a crash. This command provoked a crash in
1295        some environments:
1297          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1299        This potential security problem was recorded as CVE-2008-2371.
1301    12. For a pattern where the match had to start at the beginning or immediately
1302        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1303        pcre_dfa_exec() could read past the end of the passed subject if there was
1304        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1305        pcretest so that it places the subject at the end of its malloc-ed buffer.
1307    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1308        exec() might read past the end of the data buffer in UTF-8 mode.
1310    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1311        the data contained the byte 0x85 as part of a UTF-8 character within its
1312        first line. This applied both to normal and DFA matching.
1314    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1315        /^[^d]*?$/8 failed to match "abc".
1317    16. Added a missing copyright notice to pcrecpp_internal.h.
1319    17. Make it more clear in the documentation that values returned from
1320        pcre_exec() in ovector are byte offsets, not character counts.
1322    18. Tidied a few places to stop certain compilers from issuing warnings.
1324    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1325        supplied by Stefan Weber. I made a further small update for 7.8 because
1326        there is a change of source arrangements: the pcre_searchfuncs.c module is
1327        replaced by pcre_ucd.c.
1330    Version 7.7 07-May-08
1331    ---------------------
1333    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1334        a string to a long long, pretend we don't even have a long long." This is
1335        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1337    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1338        pre-7.6 versions, which defined a global no_arg variable instead of putting
1339        it in the RE class. (See also #8 below.)
1341    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1342        Lopes.
1344    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1346        (1) The include/exclude patterns were being applied to the whole pathnames
1347            of files, instead of just to the final components.
1349        (2) If there was more than one level of directory, the subdirectories were
1350            skipped unless they satisfied the include/exclude conditions. This is
1351            inconsistent with GNU grep (and could even be seen as contrary to the
1352            pcregrep specification - which I improved to make it absolutely clear).
1353            The action now is always to scan all levels of directory, and just
1354            apply the include/exclude patterns to regular files.
1356    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1357        --exclude_dir in the tests to avoid scanning .svn directories.
1359    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1360        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1361        doesn't support NULs in patterns.
1363    7.  Added some missing "const"s to declarations of static tables in
1364        pcre_compile.c and pcre_dfa_exec.c.
1366    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1367        caused by fix #2  above. (Subsequently also a second patch to fix the
1368        first patch. And a third patch - this was a messy problem.)
1370    9.  Applied Craig's patch to remove the use of push_back().
1372    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1373        matching function regexec().
1375    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1376        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1377        references. PCRE supports relative numbers with this syntax (I don't think
1378        Oniguruma does).
1380    12. Previously, a group with a zero repeat such as (...){0} was completely
1381        omitted from the compiled regex. However, this means that if the group
1382        was called as a subroutine from elsewhere in the pattern, things went wrong
1383        (an internal error was given). Such groups are now left in the compiled
1384        pattern, with a new opcode that causes them to be skipped at execution
1385        time.
1387    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1388        to the way PCRE behaves:
1390        (a) A lone ] character is dis-allowed (Perl treats it as data).
1392        (b) A back reference to an unmatched subpattern matches an empty string
1393            (Perl fails the current match path).
1395        (c) A data ] in a character class must be notated as \] because if the
1396            first data character in a class is ], it defines an empty class. (In
1397            Perl it is not possible to have an empty class.) The empty class []
1398            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1399            The negative empty class [^] matches any one character, independently
1400            of the DOTALL setting.
1402    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1403        non-existent subpattern following a character class starting with ']' and
1404        containing () gave an internal compiling error instead of "reference to
1405        non-existent subpattern". Fortunately, when the pattern did exist, the
1406        compiled code was correct. (When scanning forwards to check for the
1407        existencd of the subpattern, it was treating the data ']' as terminating
1408        the class, so got the count wrong. When actually compiling, the reference
1409        was subsequently set up correctly.)
1411    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1412        it was being rejected as not supported by pcre_dfa_exec(), even though
1413        other assertions are supported. I have made pcre_dfa_exec() support
1414        (*FAIL).
1416    16. The implementation of 13c above involved the invention of a new opcode,
1417        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1418        cannot be changed at match time, I realized I could make a small
1419        improvement to matching performance by compiling OP_ALLANY instead of
1420        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1421        on the OP_ANY path.
1423    17. Compiling pcretest on Windows with readline support failed without the
1424        following two fixes: (1) Make the unistd.h include conditional on
1425        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1427    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1428        ncurses library to be included for pcretest when ReadLine support is
1429        requested, but also to allow for it to be overridden. This patch came from
1430        Daniel Bergström.
1432    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1433        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1434        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1435        spotting this.
1438    Version 7.6 28-Jan-08
1439    ---------------------
1441    1.  A character class containing a very large number of characters with
1442        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1443        overflow.
1445    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1446        HAVE_LONG_LONG is not defined.
1448    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1449        bring them up to date and include new features. This patch includes:
1451        - Fixed PH's badly added libz and libbz2 support.
1452        - Fixed a problem with static linking.
1453        - Added pcredemo. [But later removed - see 7 below.]
1454        - Fixed dftables problem and added an option.
1455        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1456            HAVE_LONG_LONG.
1457        - Added readline support for pcretest.
1458        - Added an listing of the option settings after cmake has run.
1460    4.  A user submitted a patch to Makefile that makes it easy to create
1461        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1462        Makefile.am that cause it to include this special target, without
1463        affecting anything else. Note that the same mingw target plus all
1464        the other distribution libraries and programs are now supported
1465        when configuring with CMake (see 6 below) instead of with
1466        Configure/Make.
1468    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1469        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1470        exported in the Windows port". It has not yet been confirmed that the patch
1471        solves the problem, but it does no harm.
1473    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1474        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1475        with CMake, and also correct the comment about stack recursion.
1477    7.  Remove the automatic building of pcredemo from the ./configure system and
1478        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1479        of a program that users should build themselves after PCRE is installed, so
1480        building it automatically is not really right. What is more, it gave
1481        trouble in some build environments.
1483    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1486    Version 7.5 10-Jan-08
1487    ---------------------
1489    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1490        values in parens when parsing an RE using the C++ wrapper."
1492    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1493        Characters greater than 255 were excluded from the class instead of being
1494        included.
1496    3.  The same bug as (2) above applied to negated POSIX classes such as
1497        [:^space:].
1499    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1500        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1501        I have changed it.
1503    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1504        first named subpattern) and a construct such as (?&a) would reference the
1505        first named subpattern whose name started with "a" (in other words, the
1506        length check was missing). Both these problems are fixed. "Subpattern name
1507        expected" is now given for (?&) (a zero-length name), and this patch also
1508        makes it give the same error for \k'' (previously it complained that that
1509        was a reference to a non-existent subpattern).
1511    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1512        this is right because (?- can be followed by option settings as well as by
1513        digits. I have, however, made the messages clearer.
1515    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1516        than the number used in the conditional) now cause a compile-time error.
1517        This is actually not compatible with Perl, which accepts such patterns, but
1518        treats the conditional as always being FALSE (as PCRE used to), but it
1519        seems to me that giving a diagnostic is better.
1521    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1522        and messages.
1524    9.  Fix two occurrences of "backslash" in comments that should have been
1525        "backspace".
1527    10. Remove two redundant lines of code that can never be obeyed (their function
1528        was moved elsewhere).
1530    11. The program that makes PCRE's Unicode character property table had a bug
1531        which caused it to generate incorrect table entries for sequences of
1532        characters that have the same character type, but are in different scripts.
1533        It amalgamated them into a single range, with the script of the first of
1534        them. In other words, some characters were in the wrong script. There were
1535        thirteen such cases, affecting characters in the following ranges:
1537          U+002b0 - U+002c1
1538          U+0060c - U+0060d
1539          U+0061e - U+00612
1540          U+0064b - U+0065e
1541          U+0074d - U+0076d
1542          U+01800 - U+01805
1543          U+01d00 - U+01d77
1544          U+01d9b - U+01dbf
1545          U+0200b - U+0200f
1546          U+030fc - U+030fe
1547          U+03260 - U+0327f
1548          U+0fb46 - U+0fbb1
1549          U+10450 - U+1049d
1551    12. The -o option (show only the matching part of a line) for pcregrep was not
1552        compatible with GNU grep in that, if there was more than one match in a
1553        line, it showed only the first of them. It now behaves in the same way as
1554        GNU grep.
1556    13. If the -o and -v options were combined for pcregrep, it printed a blank
1557        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1558        does the same. The return code can be used to tell if there were any
1559        non-matching lines.
1561    14. Added --file-offsets and --line-offsets to pcregrep.
1563    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1564        infinitely looping recursion. The bug was that positive lookaheads were not
1565        being skipped when checking for a possible empty match (negative lookaheads
1566        and both kinds of lookbehind were skipped).
1568    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1569        inclusion of <windows.h> to before rather than after the definition of
1570        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1572    17. Specifying a possessive quantifier with a specific limit for a Unicode
1573        character property caused pcre_compile() to compile bad code, which led at
1574        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1575        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1576        caused the error; without that there was no problem.
1578    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1580    19. Added --enable-pcretest-libreadline.
1582    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1583        RE::GlobalReplace(). As a result, the number of replacements returned was
1584        double what it should be. I removed one of the increments, but Craig sent a
1585        later patch that removed the other one (the right fix) and added unit tests
1586        that check the return values (which was not done before).
1588    21. Several CMake things:
1590        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1591            the names libpcre and libpcreposix, not just pcre and pcreposix.
1593        (2) The above change means that pcretest and pcregrep are now correctly
1594            linked with the newly-built libraries, not previously installed ones.
1598    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1599        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1600        UTF-8 newline character). The key issue is that the pattern starts .*;
1601        this means that the match must be either at the beginning, or after a
1602        newline. The bug was in the code for advancing after a failed match and
1603        checking that the new position followed a newline. It was not taking
1604        account of UTF-8 characters correctly.
1606    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1607        character classes. PCRE was not treating the sequence [:...:] as a
1608        character class unless the ... were all letters. Perl, however, seems to
1609        allow any characters between [: and :], though of course it rejects as
1610        unknown any "names" that contain non-letters, because all the known class
1611        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1612        for example, whereas PCRE did not - it did not recognize a POSIX character
1613        class. This seemed a bit dangerous, so the code has been changed to be
1614        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1615        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1616        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1617        Perl does, and where it didn't before.
1619    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1620        Windows environments %n is disabled by default.
1623    Version 7.4 21-Sep-07
1624    ---------------------
1626    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1627        means that a class such as [\s] counted as "explicit reference to CR or
1628        LF". That isn't really right - the whole point of the change was to try to
1629        help when there was an actual mention of one of the two characters. So now
1630        the change happens only if \r or \n (or a literal CR or LF) character is
1631        encountered.
1633    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1634        of both had grown to the point where there were only 3 bits left.
1635        Fortunately, there was spare space in the data structure, and so I have
1636        moved the internal flags into a new 16-bit field to free up more option
1637        bits.
1639    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1640        but did not set the internal JCHANGED flag - either of these is enough to
1641        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1642        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1643        start sets both bits.
1645    4.  Added options (at build time, compile time, exec time) to change \R from
1646        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1648    5.  doc/pcresyntax.html was missing from the distribution.
1650    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1651        compatibility, even though it is no longer used.
1653    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1654        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1655        windows.h file is present (where different names are used). [This was
1656        reversed later after testing - see 16 below.]
1658    8.  Changed all #include <config.h> to #include "config.h". There were also
1659        some further <pcre.h> cases that I changed to "pcre.h".
1661    9.  When pcregrep was used with the --colour option, it missed the line ending
1662        sequence off the lines that it output.
1664    10. It was pointed out to me that arrays of string pointers cause lots of
1665        relocations when a shared library is dynamically loaded. A technique of
1666        using a single long string with a table of offsets can drastically reduce
1667        these. I have refactored PCRE in four places to do this. The result is
1668        dramatic:
1670          Originally:                          290
1671          After changing UCP table:            187
1672          After changing error message table:   43
1673          After changing table of "verbs"       36
1674          After changing table of Posix names   22
1676        Thanks to the folks working on Gregex for glib for this insight.
1678    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1679        unicode-properties was also set.
1681    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1683    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1684        checked only for CRLF.
1686    14. Added casts to pcretest.c to avoid compiler warnings.
1688    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1690    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1691        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1692        entirely. This removes changes made in 7 above.
1694    17. The CMake files have been updated, and there is now more information about
1695        building with CMake in the NON-UNIX-USE document.
1698    Version 7.3 28-Aug-07
1699    ---------------------
1701     1. In the rejigging of the build system that eventually resulted in 7.1, the
1702        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1703        brackets there is not right, since it causes compilers to look for an
1704        installed pcre.h, not the version that is in the source that is being
1705        compiled (which of course may be different). I have changed it back to:
1707          #include "pcre.h"
1709        I have a vague recollection that the change was concerned with compiling in
1710        different directories, but in the new build system, that is taken care of
1711        by the VPATH setting the Makefile.
1713     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1714        when the subject happened to end in the byte 0x85 (e.g. if the last
1715        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1716        characters but of course it shouldn't be taken as a newline when it is part
1717        of another character. The bug was that, for an unlimited repeat of . in
1718        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1719        characters when looking for a newline.
1721     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1723     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1724        in debug output.
1726     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1727        long printing in the pcrecpp unittest when running under MinGW.
1729     6. ESC_K was left out of the EBCDIC table.
1731     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1732        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1733        limit also applies to "virtual nesting" when a pattern is recursive, and in
1734        this case 1000 isn't so big. I have been able to remove this limit at the
1735        expense of backing off one optimization in certain circumstances. Normally,
1736        when pcre_exec() would call its internal match() function recursively and
1737        immediately return the result unconditionally, it uses a "tail recursion"
1738        feature to save stack. However, when a subpattern that can match an empty
1739        string has an unlimited repetition quantifier, it no longer makes this
1740        optimization. That gives it a stack frame in which to save the data for
1741        checking that an empty string has been matched. Previously this was taken
1742        from the 1000-entry workspace that had been reserved. So now there is no
1743        explicit limit, but more stack is used.
1745     8. Applied Daniel's patches to solve problems with the import/export magic
1746        syntax that is required for Windows, and which was going wrong for the
1747        pcreposix and pcrecpp parts of the library. These were overlooked when this
1748        problem was solved for the main library.
1750     9. There were some crude static tests to avoid integer overflow when computing
1751        the size of patterns that contain repeated groups with explicit upper
1752        limits. As the maximum quantifier is 65535, the maximum group length was
1753        set at 30,000 so that the product of these two numbers did not overflow a
1754        32-bit integer. However, it turns out that people want to use groups that
1755        are longer than 30,000 bytes (though not repeat them that many times).
1756        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1757        made it possible to implement the integer overflow checks in a much more
1758        dynamic way, which I have now done. The artificial limitation on group
1759        length has been removed - we now have only the limit on the total length of
1760        the compiled pattern, which depends on the LINK_SIZE setting.
1762    10. Fixed a bug in the documentation for get/copy named substring when
1763        duplicate names are permitted. If none of the named substrings are set, the
1764        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1765        empty string.
1767    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1768        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1769        because the ] is interpreted as the first data character and the
1770        terminating ] is not found. PCRE has been made compatible with Perl in this
1771        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1772        cause memory overwriting.
1774    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1775        string has been matched (to stop an infinite loop). It was not recognizing
1776        a conditional subpattern that could match an empty string if that
1777        subpattern was within another subpattern. For example, it looped when
1778        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1779        condition was not nested. This bug has been fixed.
1781    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1782        past the start of the subject in the presence of bytes with the top bit
1783        set, for example "\x8aBCD".
1785    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1786        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1788    14. Optimized (?!) to (*FAIL).
1790    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1791        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1792        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1793        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1794        does: it's just the validity check that is more restrictive.
1796    16. Inserted checks for integer overflows during escape sequence (backslash)
1797        processing, and also fixed erroneous offset values for syntax errors during
1798        backslash processing.
1800    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1801        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1803    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1804        caused an overrun.
1806    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1807        something other than just ASCII characters) inside a group that had an
1808        unlimited repeat caused a loop at compile time (while checking to see
1809        whether the group could match an empty string).
1811    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1812        [\P{Any}] did so. (Error in the code for printing property names.)
1814    21. An orphan \E inside a character class could cause a crash.
1816    22. A repeated capturing bracket such as (A)? could cause a wild memory
1817        reference during compilation.
1819    23. There are several functions in pcre_compile() that scan along a compiled
1820        expression for various reasons (e.g. to see if it's fixed length for look
1821        behind). There were bugs in these functions when a repeated \p or \P was
1822        present in the pattern. These operators have additional parameters compared
1823        with \d, etc, and these were not being taken into account when moving along
1824        the compiled data. Specifically:
1826        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1827            length.
1829        (b) An item such as \pL+ within a repeated group could cause crashes or
1830            loops.
1832        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1833            "reference to non-existent subpattern" error.
1835        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1837    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1838        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1840    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1842    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1843        character were causing crashes (broken optimization).
1845    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1846        \p or \P) caused a compile-time loop.
1848    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1849        break. For example, the unstudied pattern [\r\n]A does not match the string
1850        "\r\nA" because change 7.0/46 below moves the current point on by two
1851        characters after failing to match at the start. However, the pattern \nA
1852        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1853        the same is true. There doesn't seem any very clean way out of this, but
1854        what I have chosen to do makes the common cases work: PCRE now takes note
1855        of whether there can be an explicit match for \r or \n anywhere in the
1856        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1857        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1858        pattern has explicit CR or LF references.
1860    29. Added (*CR) etc for changing newline setting at start of pattern.
1863    Version 7.2 19-Jun-07
1864  ---------------------  ---------------------
1866   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 21  Version 7.2 01-May-07 Line 1880  Version 7.2 01-May-07
1880      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
1881      a small improvement under Linux. However, it saves one field in the frame      a small improvement under Linux. However, it saves one field in the frame
1882      in all cases.      in all cases.
1884   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
1886      (a) (?-n) (where n is a string of digits) is a relative subroutine or      (a) (?-n) (where n is a string of digits) is a relative subroutine or
1887          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
1889      (b) (?+n) is also a relative subroutine call; it refers to the nth next      (b) (?+n) is also a relative subroutine call; it refers to the nth next
1890          to be opened parentheses.          to be opened parentheses.
1892      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
1893          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
1895      (d) \K resets the start of the current match so that everything before      (d) \K resets the start of the current match so that everything before
1896          is not part of it.          is not part of it.
1898        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1900        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1901            reference syntax.
1903        (g) (?| introduces a group in which the numbering of parentheses in each
1904            alternative starts with the same number.
1906        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1908     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1911     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1912        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1913        for detecting groups that can match an empty string.
1915     9. A pattern with a very large number of alternatives (more than several
1916        hundred) was running out of internal workspace during the pre-compile
1917        phase, where pcre_compile() figures out how much memory will be needed. A
1918        bit of new cunning has reduced the workspace needed for groups with
1919        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1920        workspace instead of running out of the 4096 that are available.
1922    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1924    11. Applied patch from Google to remove an optimization that didn't quite work.
1925        The report of the bug said:
1927          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1928          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1929          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1931    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1932        it matched the wrong number of bytes.
1935  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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