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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.3 05-Jul-07  Version 8.13 30-Apr-2011
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
9    2.  Two minor typos in pcre_internal.h have been fixed.
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, not that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
110    20. If /S is present twice on a test pattern in pcretest input, it *disables*
111        studying, thereby overriding the use of -s on the command line. This is
112        necessary for one or two tests to keep the output identical in both cases.
114    21. When (*ACCEPT) was used in an assertion that matched an empty string and
115        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
117    22. When an atomic group that contained a capturing parenthesis was
118        successfully matched, but the branch in which it appeared failed, the
119        capturing was not being forgotten if a higher numbered group was later
120        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121        group 1 to "a", when in fact it should be unset. This applied to multi-
122        branched capturing and non-capturing groups, repeated or not, and also to
123        positive assertions (capturing in negative assertions is not well defined
124        in PCRE) and also to nested atomic groups.
127    Version 8.12 15-Jan-2011
128    ------------------------
130    1.  Fixed some typos in the markup of the man pages, and wrote a script that
131        checks for such things as part of the documentation building process.
133    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
134        --match-limit and --recursion-limit options (added for 8.11). In
135        particular, this made one of the standard tests fail. (The integer value
136        went into the wrong half of a long int.)
138    3.  If the --colour option was given to pcregrep with -v (invert match), it
139        did strange things, either producing crazy output, or crashing. It should,
140        of course, ignore a request for colour when reporting lines that do not
141        match.
143    4.  Another pcregrep bug caused similar problems if --colour was specified with
144        -M (multiline) and the pattern match finished with a line ending.
146    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
147        matched in multiline mode, the following line was shown as part of the
148        match. This seems wrong, so I have changed it.
150    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
151        the check for further matches in the same line (so they could be coloured)
152        to overrun the end of the current line. If another match was found, it was
153        incorrectly shown (and then shown again when found in the next line).
155    7.  If pcregrep was compiled under Windows, there was a reference to the
156        function pcregrep_exit() before it was defined. I am assuming this was
157        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
158        reported by a user. I've moved the definition above the reference.
161    Version 8.11 10-Dec-2010
162    ------------------------
164    1.  (*THEN) was not working properly if there were untried alternatives prior
165        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
166        backtracked to try for "b" instead of moving to the next alternative branch
167        at the same level (in this case, to look for "c"). The Perl documentation
168        is clear that when (*THEN) is backtracked onto, it goes to the "next
169        alternative in the innermost enclosing group".
171    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
172        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
173        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
174        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
175        (*THEN).
177    3.  If \s appeared in a character class, it removed the VT character from
178        the class, even if it had been included by some previous item, for example
179        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
180        of \s, but is part of the POSIX "space" class.)
182    4.  A partial match never returns an empty string (because you can always
183        match an empty string at the end of the subject); however the checking for
184        an empty string was starting at the "start of match" point. This has been
185        changed to the "earliest inspected character" point, because the returned
186        data for a partial match starts at this character. This means that, for
187        example, /(?<=abc)def/ gives a partial match for the subject "abc"
188        (previously it gave "no match").
190    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
191        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
192        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
193        has an implication that the given string is incomplete (because a partial
194        match is preferred over a full match). For this reason, these items now
195        give a partial match in this situation. [Aside: previously, the one case
196        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
197        match rather than a full match, which was wrong by the old rules, but is
198        now correct.]
200    6.  There was a bug in the handling of #-introduced comments, recognized when
201        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
202        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
203        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
204        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
205        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
206        places in pcre_compile().
208    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
209        comments when looking ahead for named forward references to subpatterns,
210        the only newline sequence it recognized was NL. It now handles newlines
211        according to the set newline convention.
213    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
214        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
215        cater for a lack of strerror(). These oversights have been fixed.
217    9.  Added --match-limit and --recursion-limit to pcregrep.
219    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
221    11. When the -o option was used, pcregrep was setting a return code of 1, even
222        when matches were found, and --line-buffered was not being honoured.
224    12. Added an optional parentheses number to the -o and --only-matching options
225        of pcregrep.
227    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
228        can match an empty string. The code to do it in pcretest and pcredemo
229        needed fixing:
231        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
232            only one byte after an empty string match just before CRLF (this case
233            just got forgotten; "any" and "anycrlf" were OK).
235        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
236            mode when an empty string match preceded an ASCII character followed by
237            a non-ASCII character. (The code for advancing by one character rather
238            than one byte was nonsense.)
240        (c) The pcredemo.c sample program did not have any code at all to handle
241            the cases when CRLF is a valid newline sequence.
243    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
244        as a starting offset was within the subject string. There is now a new
245        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
246        negative or greater than the length of the string. In order to test this,
247        pcretest is extended to allow the setting of negative starting offsets.
249    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
250        starting offset points to the beginning of a UTF-8 character was
251        unnecessarily clumsy. I tidied it up.
253    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
254        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
256    17. Nobody had reported that the --include_dir option, which was added in
257        release 7.7 should have been called --include-dir (hyphen, not underscore)
258        for compatibility with GNU grep. I have changed it to --include-dir, but
259        left --include_dir as an undocumented synonym, and the same for
260        --exclude-dir, though that is not available in GNU grep, at least as of
261        release 2.5.4.
263    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
264        characters from a string of bytes) have been redefined so as not to use
265        loops, in order to improve performance in some environments. At the same
266        time, I abstracted some of the common code into auxiliary macros to save
267        repetition (this should not affect the compiled code).
269    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
270        compile-time error is now given if \c is not followed by an ASCII
271        character, that is, a byte less than 128. (In EBCDIC mode, the code is
272        different, and any byte value is allowed.)
274    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
275        START_OPTIMIZE option, which is now allowed at compile time - but just
276        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
277        to pcregrep and other applications that have no direct access to PCRE
278        options. The new /Y option in pcretest sets this option when calling
279        pcre_compile().
281    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
282        back references. Groups containing recursive back references were forced to
283        be atomic by that change, but in the case of named groups, the amount of
284        memory required was incorrectly computed, leading to "Failed: internal
285        error: code overflow". This has been fixed.
287    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
288        pcretest.c, to avoid build problems in some Borland environments.
291    Version 8.10 25-Jun-2010
292    ------------------------
294    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
295        THEN.
297    2.  (*ACCEPT) was not working when inside an atomic group.
299    3.  Inside a character class, \B is treated as a literal by default, but
300        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
301        causes the error). The code is unchanged, but I tidied the documentation.
303    4.  Inside a character class, PCRE always treated \R and \X as literals,
304        whereas Perl faults them if its -w option is set. I have changed PCRE so
305        that it faults them when PCRE_EXTRA is set.
307    5.  Added support for \N, which always matches any character other than
308        newline. (It is the same as "." when PCRE_DOTALL is not set.)
310    6.  When compiling pcregrep with newer versions of gcc which may have
311        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
312        declared with attribute warn_unused_result" were given. Just casting the
313        result to (void) does not stop the warnings; a more elaborate fudge is
314        needed. I've used a macro to implement this.
316    7.  Minor change to pcretest.c to avoid a compiler warning.
318    8.  Added four artifical Unicode properties to help with an option to make
319        \s etc use properties (see next item). The new properties are: Xan
320        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
322    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
323        use Unicode properties. (*UCP) at the start of a pattern can be used to set
324        this option. Modified pcretest to add /W to test this facility. Added
325        REG_UCP to make it available via the POSIX interface.
327    10. Added --line-buffered to pcregrep.
329    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
330        studied, and the match started with a letter with a code point greater than
331        127 whose first byte was different to the first byte of the other case of
332        the letter, the other case of this starting letter was not recognized
333        (#976).
335    12. If a pattern that was studied started with a repeated Unicode property
336        test, for example, \p{Nd}+, there was the theoretical possibility of
337        setting up an incorrect bitmap of starting bytes, but fortunately it could
338        not have actually happened in practice until change 8 above was made (it
339        added property types that matched character-matching opcodes).
341    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
342        possible starting bytes for non-anchored patterns.
344    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
345        \R, and also a number of cases that involve Unicode properties, both
346        explicit and implicit when PCRE_UCP is set.
348    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
349        input, it could crash or give wrong results if characters with values
350        greater than 0xc0 were present in the subject string. (Detail: it assumed
351        UTF-8 input when processing these items.)
353    16. Added a lot of (int) casts to avoid compiler warnings in systems where
354        size_t is 64-bit (#991).
356    17. Added a check for running out of memory when PCRE is compiled with
357        --disable-stack-for-recursion (#990).
359    18. If the last data line in a file for pcretest does not have a newline on
360        the end, a newline was missing in the output.
362    19. The default pcre_chartables.c file recognizes only ASCII characters (values
363        less than 128) in its various bitmaps. However, there is a facility for
364        generating tables according to the current locale when PCRE is compiled. It
365        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
366        characters, are recognized by isspace() and therefore were getting set in
367        these tables, and indeed these tables seem to approximate to ISO 8859. This
368        caused a problem in UTF-8 mode when pcre_study() was used to create a list
369        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
370        which of course cannot start UTF-8 characters. I have changed the code so
371        that only real ASCII characters (less than 128) and the correct starting
372        bytes for UTF-8 encodings are set for characters greater than 127 when in
373        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
374        altogether.)
376    20. Added the /T option to pcretest so as to be able to run tests with non-
377        standard character tables, thus making it possible to include the tests
378        used for 19 above in the standard set of tests.
380    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
381        reference to a subpattern the other side of a comment that contains an
382        opening parenthesis caused either an internal compiling error, or a
383        reference to the wrong subpattern.
386    Version 8.02 19-Mar-2010
387    ------------------------
389    1.  The Unicode data tables have been updated to Unicode 5.2.0.
391    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
392        configured.
394    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
395        original author of that file, following a query about its status.
397    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
398        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
400    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
401        quantifier applied to a forward-referencing subroutine call, could compile
402        incorrect code or give the error "internal error: previously-checked
403        referenced subpattern not found".
405    6.  Both MS Visual Studio and Symbian OS have problems with initializing
406        variables to point to external functions. For these systems, therefore,
407        pcre_malloc etc. are now initialized to local functions that call the
408        relevant global functions.
410    7.  There were two entries missing in the vectors called coptable and poptable
411        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
412        I've fixed the data, and added a kludgy way of testing at compile time that
413        the lengths are correct (equal to the number of opcodes).
415    8.  Following on from 7, I added a similar kludge to check the length of the
416        eint vector in pcreposix.c.
418    9.  Error texts for pcre_compile() are held as one long string to avoid too
419        much relocation at load time. To find a text, the string is searched,
420        counting zeros. There was no check for running off the end of the string,
421        which could happen if a new error number was added without updating the
422        string.
424    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
426    11. \K was not working if it appeared in an atomic group or in a group that
427        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
428        \K is "not well defined" if used in an assertion. PCRE now accepts it if
429        the assertion is positive, but not if it is negative.
431    12. Change 11 fortuitously reduced the size of the stack frame used in the
432        "match()" function of pcre_exec.c by one pointer. Forthcoming
433        implementation of support for (*MARK) will need an extra pointer on the
434        stack; I have reserved it now, so that the stack frame size does not
435        decrease.
437    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
438        item in branch that calls a recursion is a subroutine call - as in the
439        second branch in the above example - was incorrectly given the compile-
440        time error "recursive call could loop indefinitely" because pcre_compile()
441        was not correctly checking the subroutine for matching a non-empty string.
443    14. The checks for overrunning compiling workspace could trigger after an
444        overrun had occurred. This is a "should never occur" error, but it can be
445        triggered by pathological patterns such as hundreds of nested parentheses.
446        The checks now trigger 100 bytes before the end of the workspace.
448    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
451    Version 8.01 19-Jan-2010
452    ------------------------
454    1.  If a pattern contained a conditional subpattern with only one branch (in
455        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
456        computed the wrong minimum data length (which is of course zero for such
457        subpatterns). This could cause incorrect "no match" results.
459    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
460        the pattern is reset in the first branch, pcre_compile() failed with
461        "internal error: code overflow at offset...". This happened only when
462        the reset was to the original external option setting. (An optimization
463        abstracts leading options settings into an external setting, which was the
464        cause of this.)
466    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
467        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
468        assertion pattern did not match (meaning that the assertion was true), it
469        was incorrectly treated as false if the SKIP had been reached during the
470        matching. This also applied to assertions used as conditions.
472    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
473        assertion subpattern, including such a pattern used as a condition,
474        unpredictable results occurred, instead of the error return
477    5.  The C++ GlobalReplace function was not working like Perl for the special
478        situation when an empty string is matched. It now does the fancy magic
479        stuff that is necessary.
481    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
482        removed. (These were left over from very, very early versions of PCRE.)
484    7.  Some cosmetic changes to the code to make life easier when compiling it
485        as part of something else:
487        (a) Change DEBUG to PCRE_DEBUG.
489        (b) In pcre_compile(), rename the member of the "branch_chain" structure
490            called "current" as "current_branch", to prevent a collision with the
491            Linux macro when compiled as a kernel module.
493        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
494            prevent a collision with the Linux macro when compiled as a kernel
495            module.
497    8.  In pcre_compile() there are some checks for integer overflows that used to
498        cast potentially large values to (double). This has been changed to that
499        when building, a check for int64_t is made, and if it is found, it is used
500        instead, thus avoiding the use of floating point arithmetic. (There is no
501        other use of FP in PCRE.) If int64_t is not found, the fallback is to
502        double.
504    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
505        2005 (difference between two addresses compared to an unsigned value).
507    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
508        custom one, because of the following reported problem in Windows:
510          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
511              under Win32.
512          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
513              therefore missing the function definition.
514          - The compiler thus generates a "C" signature for the test function.
515          - The linker fails to find the "C" function.
516          - PCRE fails to configure if asked to do so against libbz2.
518    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
519        messages were output:
521          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
522          rerunning libtoolize, to keep the correct libtool macros in-tree.
523          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
525        I have done both of these things.
527    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
528        most of the time, it *can* run out if it is given a pattern that contains a
529        runaway infinite recursion. I updated the discussion in the pcrestack man
530        page.
532    13. Now that we have gone to the x.xx style of version numbers, the minor
533        version may start with zero. Using 08 or 09 is a bad idea because users
534        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
535        interpreted as invalid octal numbers. I've updated the previous comment in
536        configure.ac, and also added a check that gives an error if 08 or 09 are
537        used.
539    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
540        causing partial matching to fail when the end of the subject matched \W
541        in a UTF-8 pattern where \W was quantified with a minimum of 3.
543    15. There were some discrepancies between the declarations in pcre_internal.h
544        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
545        their definitions. The declarations used "const uschar *" and the
546        definitions used USPTR. Even though USPTR is normally defined as "const
547        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
548        reported that: "This difference in casting confuses some C++ compilers, for
549        example, SunCC recognizes above declarations as different functions and
550        generates broken code for hbpcre." I have changed the declarations to use
551        USPTR.
553    16. GNU libtool is named differently on some systems. The autogen.sh script now
554        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
555        (FreeBSD).
557    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
558        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
559        comment: "Figure out how to create a longlong from a string: strtoll and
560        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
561        instance, but it only takes 2 args instead of 3!"
563    18. A subtle bug concerned with back references has been fixed by a change of
564        specification, with a corresponding code fix. A pattern such as
565        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
566        refers, was giving matches when it shouldn't. For example, xa=xaaa would
567        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
568        same bug. Such groups have to be quantified to be useful, or contained
569        inside another quantified group. (If there's no repetition, the reference
570        can never match.) The problem arises because, having left the group and
571        moved on to the rest of the pattern, a later failure that backtracks into
572        the group uses the captured value from the final iteration of the group
573        rather than the correct earlier one. I have fixed this in PCRE by forcing
574        any group that contains a reference to itself to be an atomic group; that
575        is, there cannot be any backtracking into it once it has completed. This is
576        similar to recursive and subroutine calls.
579    Version 8.00 19-Oct-09
580    ----------------------
582    1.  The table for translating pcre_compile() error codes into POSIX error codes
583        was out-of-date, and there was no check on the pcre_compile() error code
584        being within the table. This could lead to an OK return being given in
585        error.
587    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
588        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
589        in a Windows environment.
591    3.  The pcregrep --count option prints the count for each file even when it is
592        zero, as does GNU grep. However, pcregrep was also printing all files when
593        --files-with-matches was added. Now, when both options are given, it prints
594        counts only for those files that have at least one match. (GNU grep just
595        prints the file name in this circumstance, but including the count seems
596        more useful - otherwise, why use --count?) Also ensured that the
597        combination -clh just lists non-zero counts, with no names.
599    4.  The long form of the pcregrep -F option was incorrectly implemented as
600        --fixed_strings instead of --fixed-strings. This is an incompatible change,
601        but it seems right to fix it, and I didn't think it was worth preserving
602        the old behaviour.
604    5.  The command line items --regex=pattern and --regexp=pattern were not
605        recognized by pcregrep, which required --regex pattern or --regexp pattern
606        (with a space rather than an '='). The man page documented the '=' forms,
607        which are compatible with GNU grep; these now work.
609    6.  No libpcreposix.pc file was created for pkg-config; there was just
610        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
612    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
613        when UCP support is not needed, by modifying the Python script that
614        generates it from Unicode data files. This should not matter if the module
615        is correctly used as a library, but I received one complaint about 50K of
616        unwanted data. My guess is that the person linked everything into his
617        program rather than using a library. Anyway, it does no harm.
619    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
620        was a minimum greater than 1 for a wide character in a possessive
621        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
622        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
623        character. Chaos in the form of incorrect output or a compiling loop could
624        result.
626    9.  The restrictions on what a pattern can contain when partial matching is
627        requested for pcre_exec() have been removed. All patterns can now be
628        partially matched by this function. In addition, if there are at least two
629        slots in the offset vector, the offset of the earliest inspected character
630        for the match and the offset of the end of the subject are set in them when
631        PCRE_ERROR_PARTIAL is returned.
633    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
634        synonymous with PCRE_PARTIAL, for backwards compatibility, and
635        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
636        and may be more useful for multi-segment matching.
638    11. Partial matching with pcre_exec() is now more intuitive. A partial match
639        used to be given if ever the end of the subject was reached; now it is
640        given only if matching could not proceed because another character was
641        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
642        string "Z", which now yields "no match" instead of "partial match". In the
643        case of pcre_dfa_exec(), "no match" is given if every matching path for the
644        final character ended with (*FAIL).
646    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
647        if the pattern had a "must contain" character that was already found in the
648        earlier partial match, unless partial matching was again requested. For
649        example, with the pattern /dog.(body)?/, the "must contain" character is
650        "g". If the first part-match was for the string "dog", restarting with
651        "sbody" failed. This bug has been fixed.
653    13. The string returned by pcre_dfa_exec() after a partial match has been
654        changed so that it starts at the first inspected character rather than the
655        first character of the match. This makes a difference only if the pattern
656        starts with a lookbehind assertion or \b or \B (\K is not supported by
657        pcre_dfa_exec()). It's an incompatible change, but it makes the two
658        matching functions compatible, and I think it's the right thing to do.
660    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
661        so that the demonstration program is easily available in environments where
662        PCRE has not been installed from source.
664    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
665        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
666        library.
668    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
669        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
670        is not the first non-POSIX option to be added. Clearly some people find
671        these options useful.
673    17. If a caller to the POSIX matching function regexec() passes a non-zero
674        value for nmatch with a NULL value for pmatch, the value of
675        nmatch is forced to zero.
677    18. RunGrepTest did not have a test for the availability of the -u option of
678        the diff command, as RunTest does. It now checks in the same way as
679        RunTest, and also checks for the -b option.
681    19. If an odd number of negated classes containing just a single character
682        interposed, within parentheses, between a forward reference to a named
683        subpattern and the definition of the subpattern, compilation crashed with
684        an internal error, complaining that it could not find the referenced
685        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
686        [The bug was that it was starting one character too far in when skipping
687        over the character class, thus treating the ] as data rather than
688        terminating the class. This meant it could skip too much.]
690    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
691        /g option in pcretest when the pattern contains \K, which makes it possible
692        to have an empty string match not at the start, even when the pattern is
693        anchored. Updated pcretest and pcredemo to use this option.
695    21. If the maximum number of capturing subpatterns in a recursion was greater
696        than the maximum at the outer level, the higher number was returned, but
697        with unset values at the outer level. The correct (outer level) value is
698        now given.
700    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
701        PCRE did not set those parentheses (unlike Perl). I have now found a way to
702        make it do so. The string so far is captured, making this feature
703        compatible with Perl.
705    23. The tests have been re-organized, adding tests 11 and 12, to make it
706        possible to check the Perl 5.10 features against Perl 5.10.
708    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
709        pattern matches a fixed length string. PCRE did not allow this; now it
710        does. Neither allows recursion.
712    25. I finally figured out how to implement a request to provide the minimum
713        length of subject string that was needed in order to match a given pattern.
714        (It was back references and recursion that I had previously got hung up
715        on.) This code has now been added to pcre_study(); it finds a lower bound
716        to the length of subject needed. It is not necessarily the greatest lower
717        bound, but using it to avoid searching strings that are too short does give
718        some useful speed-ups. The value is available to calling programs via
719        pcre_fullinfo().
721    26. While implementing 25, I discovered to my embarrassment that pcretest had
722        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
723        study optimizations had never been tested with that matching function.
724        Oops. What is worse, even when it was passed study data, there was a bug in
725        pcre_dfa_exec() that meant it never actually used it. Double oops. There
726        were also very few tests of studied patterns with pcre_dfa_exec().
728    27. If (?| is used to create subpatterns with duplicate numbers, they are now
729        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
730        on the other side of the coin, they are no longer allowed to have different
731        names, because these cannot be distinguished in PCRE, and this has caused
732        confusion. (This is a difference from Perl.)
734    28. When duplicate subpattern names are present (necessarily with different
735        numbers, as required by 27 above), and a test is made by name in a
736        conditional pattern, either for a subpattern having been matched, or for
737        recursion in such a pattern, all the associated numbered subpatterns are
738        tested, and the overall condition is true if the condition is true for any
739        one of them. This is the way Perl works, and is also more like the way
740        testing by number works.
743    Version 7.9 11-Apr-09
744    ---------------------
746    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
747        (pcretest), all targets were linked against these libraries. This included
748        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
749        libraries. This caused unwanted dependencies to be created. This problem
750        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
751        pcretest is linked with readline.
753    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
754        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
755        moved outside it again, because FALSE and TRUE are already defined in AIX,
756        but BOOL is not.
758    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
759        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
761    4.  The pcregrep documentation said spaces were inserted as well as colons (or
762        hyphens) following file names and line numbers when outputting matching
763        lines. This is not true; no spaces are inserted. I have also clarified the
764        wording for the --colour (or --color) option.
766    5.  In pcregrep, when --colour was used with -o, the list of matching strings
767        was not coloured; this is different to GNU grep, so I have changed it to be
768        the same.
770    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
771        each matching line was coloured. Now it goes on to look for further matches
772        of any of the test patterns, which is the same behaviour as GNU grep.
774    7.  A pattern that could match an empty string could cause pcregrep to loop; it
775        doesn't make sense to accept an empty string match in pcregrep, so I have
776        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
777        seems to be how GNU grep behaves.
779    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
780        start or after a newline", because the conditional assertion was not being
781        correctly handled. The rule now is that both the assertion and what follows
782        in the first alternative must satisfy the test.
784    9.  If auto-callout was enabled in a pattern with a conditional group whose
785        condition was an assertion, PCRE could crash during matching, both with
786        pcre_exec() and pcre_dfa_exec().
788    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
789        used for matching.
791    11. Unicode property support in character classes was not working for
792        characters (bytes) greater than 127 when not in UTF-8 mode.
794    12. Added the -M command line option to pcretest.
796    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
798    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
800    16. Added comments and documentation about mis-use of no_arg in the C++
801        wrapper.
803    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
804        from Martin Jerabek that uses macro names for all relevant character and
805        string constants.
807    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
808        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
809        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
810        these, but not everybody uses configure.
812    19. A conditional group that had only one branch was not being correctly
813        recognized as an item that could match an empty string. This meant that an
814        enclosing group might also not be so recognized, causing infinite looping
815        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
816        with the subject "ab", where knowledge that the repeated group can match
817        nothing is needed in order to break the loop.
819    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
820        exec(), but without supplying a callout function, matching went wrong.
822    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
823        leak if the size of the offset vector was greater than 30. When the vector
824        is smaller, the saved offsets during recursion go onto a local stack
825        vector, but for larger vectors malloc() is used. It was failing to free
826        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
827        error, in fact).
829    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
830        heapframe that is used only when UTF-8 support is enabled. This caused no
831        problem, but was untidy.
833    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
834        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
835        included within another project.
837    24. Steven Van Ingelgem's patches to add more options to the CMake support,
838        slightly modified by me:
840          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
841              not building pcregrep.
843          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
844              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
846    25. Forward references, both numeric and by name, in patterns that made use of
847        duplicate group numbers, could behave incorrectly or give incorrect errors,
848        because when scanning forward to find the reference group, PCRE was not
849        taking into account the duplicate group numbers. A pattern such as
850        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
852    26. Changed a few more instances of "const unsigned char *" to USPTR, making
853        the feature of a custom pointer more persuasive (as requested by a user).
855    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
856        pcretest.c, inside #ifndefs, because it seems they are sometimes already
857        pre-defined.
859    28. Added support for (*UTF8) at the start of a pattern.
861    29. Arrange for flags added by the "release type" setting in CMake to be shown
862        in the configuration summary.
865    Version 7.8 05-Sep-08
866    ---------------------
868    1.  Replaced UCP searching code with optimized version as implemented for Ad
869        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
870        stage table and inline lookup instead of a function, giving speed ups of 2
871        to 5 times on some simple patterns that I tested. Permission was given to
872        distribute the MultiStage2.py script that generates the tables (it's not in
873        the tarball, but is in the Subversion repository).
875    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
876        scripts.
878    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
879        a group with a zero qualifier. The result of the study could be incorrect,
880        or the function might crash, depending on the pattern.
882    4.  Caseless matching was not working for non-ASCII characters in back
883        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
884        It now works when Unicode Property Support is available.
886    5.  In pcretest, an escape such as \x{de} in the data was always generating
887        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
888        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
889        truncation.
891    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
893    7.  Added two (int) casts to pcregrep when printing the difference of two
894        pointers, in case they are 64-bit values.
896    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
897        test 2 if it fails.
899    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
900        and a #define of that name to empty if it is not externally set. This is to
901        allow users of MSVC to set it if necessary.
903    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
904        the convenience functions in the pcre_get.c source file.
906    11. An option change at the start of a pattern that had top-level alternatives
907        could cause overwriting and/or a crash. This command provoked a crash in
908        some environments:
910          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
912        This potential security problem was recorded as CVE-2008-2371.
914    12. For a pattern where the match had to start at the beginning or immediately
915        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
916        pcre_dfa_exec() could read past the end of the passed subject if there was
917        no match. To help with detecting such bugs (e.g. with valgrind), I modified
918        pcretest so that it places the subject at the end of its malloc-ed buffer.
920    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
921        exec() might read past the end of the data buffer in UTF-8 mode.
923    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
924        the data contained the byte 0x85 as part of a UTF-8 character within its
925        first line. This applied both to normal and DFA matching.
927    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
928        /^[^d]*?$/8 failed to match "abc".
930    16. Added a missing copyright notice to pcrecpp_internal.h.
932    17. Make it more clear in the documentation that values returned from
933        pcre_exec() in ovector are byte offsets, not character counts.
935    18. Tidied a few places to stop certain compilers from issuing warnings.
937    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
938        supplied by Stefan Weber. I made a further small update for 7.8 because
939        there is a change of source arrangements: the pcre_searchfuncs.c module is
940        replaced by pcre_ucd.c.
943    Version 7.7 07-May-08
944    ---------------------
946    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
947        a string to a long long, pretend we don't even have a long long." This is
948        done by checking for the strtoq, strtoll, and _strtoi64 functions.
950    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
951        pre-7.6 versions, which defined a global no_arg variable instead of putting
952        it in the RE class. (See also #8 below.)
954    3.  Remove a line of dead code, identified by coverity and reported by Nuno
955        Lopes.
957    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
959        (1) The include/exclude patterns were being applied to the whole pathnames
960            of files, instead of just to the final components.
962        (2) If there was more than one level of directory, the subdirectories were
963            skipped unless they satisfied the include/exclude conditions. This is
964            inconsistent with GNU grep (and could even be seen as contrary to the
965            pcregrep specification - which I improved to make it absolutely clear).
966            The action now is always to scan all levels of directory, and just
967            apply the include/exclude patterns to regular files.
969    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
970        --exclude_dir in the tests to avoid scanning .svn directories.
972    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
973        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
974        doesn't support NULs in patterns.
976    7.  Added some missing "const"s to declarations of static tables in
977        pcre_compile.c and pcre_dfa_exec.c.
979    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
980        caused by fix #2  above. (Subsequently also a second patch to fix the
981        first patch. And a third patch - this was a messy problem.)
983    9.  Applied Craig's patch to remove the use of push_back().
985    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
986        matching function regexec().
988    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
989        which, however, unlike Perl's \g{...}, are subroutine calls, not back
990        references. PCRE supports relative numbers with this syntax (I don't think
991        Oniguruma does).
993    12. Previously, a group with a zero repeat such as (...){0} was completely
994        omitted from the compiled regex. However, this means that if the group
995        was called as a subroutine from elsewhere in the pattern, things went wrong
996        (an internal error was given). Such groups are now left in the compiled
997        pattern, with a new opcode that causes them to be skipped at execution
998        time.
1000    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1001        to the way PCRE behaves:
1003        (a) A lone ] character is dis-allowed (Perl treats it as data).
1005        (b) A back reference to an unmatched subpattern matches an empty string
1006            (Perl fails the current match path).
1008        (c) A data ] in a character class must be notated as \] because if the
1009            first data character in a class is ], it defines an empty class. (In
1010            Perl it is not possible to have an empty class.) The empty class []
1011            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1012            The negative empty class [^] matches any one character, independently
1013            of the DOTALL setting.
1015    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1016        non-existent subpattern following a character class starting with ']' and
1017        containing () gave an internal compiling error instead of "reference to
1018        non-existent subpattern". Fortunately, when the pattern did exist, the
1019        compiled code was correct. (When scanning forwards to check for the
1020        existencd of the subpattern, it was treating the data ']' as terminating
1021        the class, so got the count wrong. When actually compiling, the reference
1022        was subsequently set up correctly.)
1024    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1025        it was being rejected as not supported by pcre_dfa_exec(), even though
1026        other assertions are supported. I have made pcre_dfa_exec() support
1027        (*FAIL).
1029    16. The implementation of 13c above involved the invention of a new opcode,
1030        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1031        cannot be changed at match time, I realized I could make a small
1032        improvement to matching performance by compiling OP_ALLANY instead of
1033        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1034        on the OP_ANY path.
1036    17. Compiling pcretest on Windows with readline support failed without the
1037        following two fixes: (1) Make the unistd.h include conditional on
1038        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1040    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1041        ncurses library to be included for pcretest when ReadLine support is
1042        requested, but also to allow for it to be overridden. This patch came from
1043        Daniel Bergström.
1045    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1046        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1047        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1048        spotting this.
1051    Version 7.6 28-Jan-08
1052    ---------------------
1054    1.  A character class containing a very large number of characters with
1055        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1056        overflow.
1058    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1059        HAVE_LONG_LONG is not defined.
1061    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1062        bring them up to date and include new features. This patch includes:
1064        - Fixed PH's badly added libz and libbz2 support.
1065        - Fixed a problem with static linking.
1066        - Added pcredemo. [But later removed - see 7 below.]
1067        - Fixed dftables problem and added an option.
1068        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1069            HAVE_LONG_LONG.
1070        - Added readline support for pcretest.
1071        - Added an listing of the option settings after cmake has run.
1073    4.  A user submitted a patch to Makefile that makes it easy to create
1074        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1075        Makefile.am that cause it to include this special target, without
1076        affecting anything else. Note that the same mingw target plus all
1077        the other distribution libraries and programs are now supported
1078        when configuring with CMake (see 6 below) instead of with
1079        Configure/Make.
1081    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1082        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1083        exported in the Windows port". It has not yet been confirmed that the patch
1084        solves the problem, but it does no harm.
1086    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1087        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1088        with CMake, and also correct the comment about stack recursion.
1090    7.  Remove the automatic building of pcredemo from the ./configure system and
1091        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1092        of a program that users should build themselves after PCRE is installed, so
1093        building it automatically is not really right. What is more, it gave
1094        trouble in some build environments.
1096    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1099    Version 7.5 10-Jan-08
1100    ---------------------
1102    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1103        values in parens when parsing an RE using the C++ wrapper."
1105    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1106        Characters greater than 255 were excluded from the class instead of being
1107        included.
1109    3.  The same bug as (2) above applied to negated POSIX classes such as
1110        [:^space:].
1112    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1113        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1114        I have changed it.
1116    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1117        first named subpattern) and a construct such as (?&a) would reference the
1118        first named subpattern whose name started with "a" (in other words, the
1119        length check was missing). Both these problems are fixed. "Subpattern name
1120        expected" is now given for (?&) (a zero-length name), and this patch also
1121        makes it give the same error for \k'' (previously it complained that that
1122        was a reference to a non-existent subpattern).
1124    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1125        this is right because (?- can be followed by option settings as well as by
1126        digits. I have, however, made the messages clearer.
1128    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1129        than the number used in the conditional) now cause a compile-time error.
1130        This is actually not compatible with Perl, which accepts such patterns, but
1131        treats the conditional as always being FALSE (as PCRE used to), but it
1132        seems to me that giving a diagnostic is better.
1134    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1135        and messages.
1137    9.  Fix two occurrences of "backslash" in comments that should have been
1138        "backspace".
1140    10. Remove two redundant lines of code that can never be obeyed (their function
1141        was moved elsewhere).
1143    11. The program that makes PCRE's Unicode character property table had a bug
1144        which caused it to generate incorrect table entries for sequences of
1145        characters that have the same character type, but are in different scripts.
1146        It amalgamated them into a single range, with the script of the first of
1147        them. In other words, some characters were in the wrong script. There were
1148        thirteen such cases, affecting characters in the following ranges:
1150          U+002b0 - U+002c1
1151          U+0060c - U+0060d
1152          U+0061e - U+00612
1153          U+0064b - U+0065e
1154          U+0074d - U+0076d
1155          U+01800 - U+01805
1156          U+01d00 - U+01d77
1157          U+01d9b - U+01dbf
1158          U+0200b - U+0200f
1159          U+030fc - U+030fe
1160          U+03260 - U+0327f
1161          U+0fb46 - U+0fbb1
1162          U+10450 - U+1049d
1164    12. The -o option (show only the matching part of a line) for pcregrep was not
1165        compatible with GNU grep in that, if there was more than one match in a
1166        line, it showed only the first of them. It now behaves in the same way as
1167        GNU grep.
1169    13. If the -o and -v options were combined for pcregrep, it printed a blank
1170        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1171        does the same. The return code can be used to tell if there were any
1172        non-matching lines.
1174    14. Added --file-offsets and --line-offsets to pcregrep.
1176    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1177        infinitely looping recursion. The bug was that positive lookaheads were not
1178        being skipped when checking for a possible empty match (negative lookaheads
1179        and both kinds of lookbehind were skipped).
1181    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1182        inclusion of <windows.h> to before rather than after the definition of
1183        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1185    17. Specifying a possessive quantifier with a specific limit for a Unicode
1186        character property caused pcre_compile() to compile bad code, which led at
1187        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1188        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1189        caused the error; without that there was no problem.
1191    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1193    19. Added --enable-pcretest-libreadline.
1195    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1196        RE::GlobalReplace(). As a result, the number of replacements returned was
1197        double what it should be. I removed one of the increments, but Craig sent a
1198        later patch that removed the other one (the right fix) and added unit tests
1199        that check the return values (which was not done before).
1201    21. Several CMake things:
1203        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1204            the names libpcre and libpcreposix, not just pcre and pcreposix.
1206        (2) The above change means that pcretest and pcregrep are now correctly
1207            linked with the newly-built libraries, not previously installed ones.
1211    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1212        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1213        UTF-8 newline character). The key issue is that the pattern starts .*;
1214        this means that the match must be either at the beginning, or after a
1215        newline. The bug was in the code for advancing after a failed match and
1216        checking that the new position followed a newline. It was not taking
1217        account of UTF-8 characters correctly.
1219    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1220        character classes. PCRE was not treating the sequence [:...:] as a
1221        character class unless the ... were all letters. Perl, however, seems to
1222        allow any characters between [: and :], though of course it rejects as
1223        unknown any "names" that contain non-letters, because all the known class
1224        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1225        for example, whereas PCRE did not - it did not recognize a POSIX character
1226        class. This seemed a bit dangerous, so the code has been changed to be
1227        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1228        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1229        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1230        Perl does, and where it didn't before.
1232    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1233        Windows environments %n is disabled by default.
1236    Version 7.4 21-Sep-07
1237    ---------------------
1239    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1240        means that a class such as [\s] counted as "explicit reference to CR or
1241        LF". That isn't really right - the whole point of the change was to try to
1242        help when there was an actual mention of one of the two characters. So now
1243        the change happens only if \r or \n (or a literal CR or LF) character is
1244        encountered.
1246    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1247        of both had grown to the point where there were only 3 bits left.
1248        Fortunately, there was spare space in the data structure, and so I have
1249        moved the internal flags into a new 16-bit field to free up more option
1250        bits.
1252    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1253        but did not set the internal JCHANGED flag - either of these is enough to
1254        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1255        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1256        start sets both bits.
1258    4.  Added options (at build time, compile time, exec time) to change \R from
1259        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1261    5.  doc/pcresyntax.html was missing from the distribution.
1263    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1264        compatibility, even though it is no longer used.
1266    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1267        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1268        windows.h file is present (where different names are used). [This was
1269        reversed later after testing - see 16 below.]
1271    8.  Changed all #include <config.h> to #include "config.h". There were also
1272        some further <pcre.h> cases that I changed to "pcre.h".
1274    9.  When pcregrep was used with the --colour option, it missed the line ending
1275        sequence off the lines that it output.
1277    10. It was pointed out to me that arrays of string pointers cause lots of
1278        relocations when a shared library is dynamically loaded. A technique of
1279        using a single long string with a table of offsets can drastically reduce
1280        these. I have refactored PCRE in four places to do this. The result is
1281        dramatic:
1283          Originally:                          290
1284          After changing UCP table:            187
1285          After changing error message table:   43
1286          After changing table of "verbs"       36
1287          After changing table of Posix names   22
1289        Thanks to the folks working on Gregex for glib for this insight.
1291    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1292        unicode-properties was also set.
1294    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1296    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1297        checked only for CRLF.
1299    14. Added casts to pcretest.c to avoid compiler warnings.
1301    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1303    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1304        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1305        entirely. This removes changes made in 7 above.
1307    17. The CMake files have been updated, and there is now more information about
1308        building with CMake in the NON-UNIX-USE document.
1311    Version 7.3 28-Aug-07
1312  ---------------------  ---------------------
1314   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 29  Version 7.3 05-Jul-07 Line 1336  Version 7.3 05-Jul-07
1336   4. Debugging: adjusted the names of opcodes for different kinds of parentheses   4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1337      in debug output.      in debug output.
1339   5. Arrange to use "%I64d" instead of "%lld" for long printing in the pcrecpp   5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1340      unittest when running under MinGW.      long printing in the pcrecpp unittest when running under MinGW.
1342   6. ESC_K was left out of the EBCDIC table.   6. ESC_K was left out of the EBCDIC table.
# Line 53  Version 7.3 05-Jul-07 Line 1360  Version 7.3 05-Jul-07
1360      pcreposix and pcrecpp parts of the library. These were overlooked when this      pcreposix and pcrecpp parts of the library. These were overlooked when this
1361      problem was solved for the main library.      problem was solved for the main library.
1363     9. There were some crude static tests to avoid integer overflow when computing
1364        the size of patterns that contain repeated groups with explicit upper
1365        limits. As the maximum quantifier is 65535, the maximum group length was
1366        set at 30,000 so that the product of these two numbers did not overflow a
1367        32-bit integer. However, it turns out that people want to use groups that
1368        are longer than 30,000 bytes (though not repeat them that many times).
1369        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1370        made it possible to implement the integer overflow checks in a much more
1371        dynamic way, which I have now done. The artificial limitation on group
1372        length has been removed - we now have only the limit on the total length of
1373        the compiled pattern, which depends on the LINK_SIZE setting.
1375    10. Fixed a bug in the documentation for get/copy named substring when
1376        duplicate names are permitted. If none of the named substrings are set, the
1377        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1378        empty string.
1380    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1381        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1382        because the ] is interpreted as the first data character and the
1383        terminating ] is not found. PCRE has been made compatible with Perl in this
1384        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1385        cause memory overwriting.
1387    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1388        string has been matched (to stop an infinite loop). It was not recognizing
1389        a conditional subpattern that could match an empty string if that
1390        subpattern was within another subpattern. For example, it looped when
1391        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1392        condition was not nested. This bug has been fixed.
1394    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1395        past the start of the subject in the presence of bytes with the top bit
1396        set, for example "\x8aBCD".
1398    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1399        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1401    14. Optimized (?!) to (*FAIL).
1403    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1404        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1405        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1406        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1407        does: it's just the validity check that is more restrictive.
1409    16. Inserted checks for integer overflows during escape sequence (backslash)
1410        processing, and also fixed erroneous offset values for syntax errors during
1411        backslash processing.
1413    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1414        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1416    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1417        caused an overrun.
1419    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1420        something other than just ASCII characters) inside a group that had an
1421        unlimited repeat caused a loop at compile time (while checking to see
1422        whether the group could match an empty string).
1424    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1425        [\P{Any}] did so. (Error in the code for printing property names.)
1427    21. An orphan \E inside a character class could cause a crash.
1429    22. A repeated capturing bracket such as (A)? could cause a wild memory
1430        reference during compilation.
1432    23. There are several functions in pcre_compile() that scan along a compiled
1433        expression for various reasons (e.g. to see if it's fixed length for look
1434        behind). There were bugs in these functions when a repeated \p or \P was
1435        present in the pattern. These operators have additional parameters compared
1436        with \d, etc, and these were not being taken into account when moving along
1437        the compiled data. Specifically:
1439        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1440            length.
1442        (b) An item such as \pL+ within a repeated group could cause crashes or
1443            loops.
1445        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1446            "reference to non-existent subpattern" error.
1448        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1450    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1451        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1453    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1455    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1456        character were causing crashes (broken optimization).
1458    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1459        \p or \P) caused a compile-time loop.
1461    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1462        break. For example, the unstudied pattern [\r\n]A does not match the string
1463        "\r\nA" because change 7.0/46 below moves the current point on by two
1464        characters after failing to match at the start. However, the pattern \nA
1465        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1466        the same is true. There doesn't seem any very clean way out of this, but
1467        what I have chosen to do makes the common cases work: PCRE now takes note
1468        of whether there can be an explicit match for \r or \n anywhere in the
1469        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1470        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1471        pattern has explicit CR or LF references.
1473    29. Added (*CR) etc for changing newline setting at start of pattern.
1476  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
1477  ---------------------  ---------------------

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