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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.2 01-May-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.
115    Version 8.12 15-Jan-2011
116    ------------------------
118    1.  Fixed some typos in the markup of the man pages, and wrote a script that
119        checks for such things as part of the documentation building process.
121    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
122        --match-limit and --recursion-limit options (added for 8.11). In
123        particular, this made one of the standard tests fail. (The integer value
124        went into the wrong half of a long int.)
126    3.  If the --colour option was given to pcregrep with -v (invert match), it
127        did strange things, either producing crazy output, or crashing. It should,
128        of course, ignore a request for colour when reporting lines that do not
129        match.
131    4.  Another pcregrep bug caused similar problems if --colour was specified with
132        -M (multiline) and the pattern match finished with a line ending.
134    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
135        matched in multiline mode, the following line was shown as part of the
136        match. This seems wrong, so I have changed it.
138    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
139        the check for further matches in the same line (so they could be coloured)
140        to overrun the end of the current line. If another match was found, it was
141        incorrectly shown (and then shown again when found in the next line).
143    7.  If pcregrep was compiled under Windows, there was a reference to the
144        function pcregrep_exit() before it was defined. I am assuming this was
145        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
146        reported by a user. I've moved the definition above the reference.
149    Version 8.11 10-Dec-2010
150    ------------------------
152    1.  (*THEN) was not working properly if there were untried alternatives prior
153        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
154        backtracked to try for "b" instead of moving to the next alternative branch
155        at the same level (in this case, to look for "c"). The Perl documentation
156        is clear that when (*THEN) is backtracked onto, it goes to the "next
157        alternative in the innermost enclosing group".
159    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
160        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
161        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
162        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
163        (*THEN).
165    3.  If \s appeared in a character class, it removed the VT character from
166        the class, even if it had been included by some previous item, for example
167        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
168        of \s, but is part of the POSIX "space" class.)
170    4.  A partial match never returns an empty string (because you can always
171        match an empty string at the end of the subject); however the checking for
172        an empty string was starting at the "start of match" point. This has been
173        changed to the "earliest inspected character" point, because the returned
174        data for a partial match starts at this character. This means that, for
175        example, /(?<=abc)def/ gives a partial match for the subject "abc"
176        (previously it gave "no match").
178    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
179        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
180        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
181        has an implication that the given string is incomplete (because a partial
182        match is preferred over a full match). For this reason, these items now
183        give a partial match in this situation. [Aside: previously, the one case
184        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
185        match rather than a full match, which was wrong by the old rules, but is
186        now correct.]
188    6.  There was a bug in the handling of #-introduced comments, recognized when
189        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
190        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
191        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
192        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
193        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
194        places in pcre_compile().
196    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
197        comments when looking ahead for named forward references to subpatterns,
198        the only newline sequence it recognized was NL. It now handles newlines
199        according to the set newline convention.
201    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
202        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
203        cater for a lack of strerror(). These oversights have been fixed.
205    9.  Added --match-limit and --recursion-limit to pcregrep.
207    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
209    11. When the -o option was used, pcregrep was setting a return code of 1, even
210        when matches were found, and --line-buffered was not being honoured.
212    12. Added an optional parentheses number to the -o and --only-matching options
213        of pcregrep.
215    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
216        can match an empty string. The code to do it in pcretest and pcredemo
217        needed fixing:
219        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
220            only one byte after an empty string match just before CRLF (this case
221            just got forgotten; "any" and "anycrlf" were OK).
223        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
224            mode when an empty string match preceded an ASCII character followed by
225            a non-ASCII character. (The code for advancing by one character rather
226            than one byte was nonsense.)
228        (c) The pcredemo.c sample program did not have any code at all to handle
229            the cases when CRLF is a valid newline sequence.
231    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
232        as a starting offset was within the subject string. There is now a new
233        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
234        negative or greater than the length of the string. In order to test this,
235        pcretest is extended to allow the setting of negative starting offsets.
237    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
238        starting offset points to the beginning of a UTF-8 character was
239        unnecessarily clumsy. I tidied it up.
241    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
242        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
244    17. Nobody had reported that the --include_dir option, which was added in
245        release 7.7 should have been called --include-dir (hyphen, not underscore)
246        for compatibility with GNU grep. I have changed it to --include-dir, but
247        left --include_dir as an undocumented synonym, and the same for
248        --exclude-dir, though that is not available in GNU grep, at least as of
249        release 2.5.4.
251    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
252        characters from a string of bytes) have been redefined so as not to use
253        loops, in order to improve performance in some environments. At the same
254        time, I abstracted some of the common code into auxiliary macros to save
255        repetition (this should not affect the compiled code).
257    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
258        compile-time error is now given if \c is not followed by an ASCII
259        character, that is, a byte less than 128. (In EBCDIC mode, the code is
260        different, and any byte value is allowed.)
262    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
263        START_OPTIMIZE option, which is now allowed at compile time - but just
264        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
265        to pcregrep and other applications that have no direct access to PCRE
266        options. The new /Y option in pcretest sets this option when calling
267        pcre_compile().
269    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
270        back references. Groups containing recursive back references were forced to
271        be atomic by that change, but in the case of named groups, the amount of
272        memory required was incorrectly computed, leading to "Failed: internal
273        error: code overflow". This has been fixed.
275    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
276        pcretest.c, to avoid build problems in some Borland environments.
279    Version 8.10 25-Jun-2010
280    ------------------------
282    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
283        THEN.
285    2.  (*ACCEPT) was not working when inside an atomic group.
287    3.  Inside a character class, \B is treated as a literal by default, but
288        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
289        causes the error). The code is unchanged, but I tidied the documentation.
291    4.  Inside a character class, PCRE always treated \R and \X as literals,
292        whereas Perl faults them if its -w option is set. I have changed PCRE so
293        that it faults them when PCRE_EXTRA is set.
295    5.  Added support for \N, which always matches any character other than
296        newline. (It is the same as "." when PCRE_DOTALL is not set.)
298    6.  When compiling pcregrep with newer versions of gcc which may have
299        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
300        declared with attribute warn_unused_result" were given. Just casting the
301        result to (void) does not stop the warnings; a more elaborate fudge is
302        needed. I've used a macro to implement this.
304    7.  Minor change to pcretest.c to avoid a compiler warning.
306    8.  Added four artifical Unicode properties to help with an option to make
307        \s etc use properties (see next item). The new properties are: Xan
308        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
310    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
311        use Unicode properties. (*UCP) at the start of a pattern can be used to set
312        this option. Modified pcretest to add /W to test this facility. Added
313        REG_UCP to make it available via the POSIX interface.
315    10. Added --line-buffered to pcregrep.
317    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
318        studied, and the match started with a letter with a code point greater than
319        127 whose first byte was different to the first byte of the other case of
320        the letter, the other case of this starting letter was not recognized
321        (#976).
323    12. If a pattern that was studied started with a repeated Unicode property
324        test, for example, \p{Nd}+, there was the theoretical possibility of
325        setting up an incorrect bitmap of starting bytes, but fortunately it could
326        not have actually happened in practice until change 8 above was made (it
327        added property types that matched character-matching opcodes).
329    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
330        possible starting bytes for non-anchored patterns.
332    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
333        \R, and also a number of cases that involve Unicode properties, both
334        explicit and implicit when PCRE_UCP is set.
336    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
337        input, it could crash or give wrong results if characters with values
338        greater than 0xc0 were present in the subject string. (Detail: it assumed
339        UTF-8 input when processing these items.)
341    16. Added a lot of (int) casts to avoid compiler warnings in systems where
342        size_t is 64-bit (#991).
344    17. Added a check for running out of memory when PCRE is compiled with
345        --disable-stack-for-recursion (#990).
347    18. If the last data line in a file for pcretest does not have a newline on
348        the end, a newline was missing in the output.
350    19. The default pcre_chartables.c file recognizes only ASCII characters (values
351        less than 128) in its various bitmaps. However, there is a facility for
352        generating tables according to the current locale when PCRE is compiled. It
353        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
354        characters, are recognized by isspace() and therefore were getting set in
355        these tables, and indeed these tables seem to approximate to ISO 8859. This
356        caused a problem in UTF-8 mode when pcre_study() was used to create a list
357        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
358        which of course cannot start UTF-8 characters. I have changed the code so
359        that only real ASCII characters (less than 128) and the correct starting
360        bytes for UTF-8 encodings are set for characters greater than 127 when in
361        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
362        altogether.)
364    20. Added the /T option to pcretest so as to be able to run tests with non-
365        standard character tables, thus making it possible to include the tests
366        used for 19 above in the standard set of tests.
368    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
369        reference to a subpattern the other side of a comment that contains an
370        opening parenthesis caused either an internal compiling error, or a
371        reference to the wrong subpattern.
374    Version 8.02 19-Mar-2010
375    ------------------------
377    1.  The Unicode data tables have been updated to Unicode 5.2.0.
379    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
380        configured.
382    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
383        original author of that file, following a query about its status.
385    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
386        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
388    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
389        quantifier applied to a forward-referencing subroutine call, could compile
390        incorrect code or give the error "internal error: previously-checked
391        referenced subpattern not found".
393    6.  Both MS Visual Studio and Symbian OS have problems with initializing
394        variables to point to external functions. For these systems, therefore,
395        pcre_malloc etc. are now initialized to local functions that call the
396        relevant global functions.
398    7.  There were two entries missing in the vectors called coptable and poptable
399        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
400        I've fixed the data, and added a kludgy way of testing at compile time that
401        the lengths are correct (equal to the number of opcodes).
403    8.  Following on from 7, I added a similar kludge to check the length of the
404        eint vector in pcreposix.c.
406    9.  Error texts for pcre_compile() are held as one long string to avoid too
407        much relocation at load time. To find a text, the string is searched,
408        counting zeros. There was no check for running off the end of the string,
409        which could happen if a new error number was added without updating the
410        string.
412    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
414    11. \K was not working if it appeared in an atomic group or in a group that
415        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
416        \K is "not well defined" if used in an assertion. PCRE now accepts it if
417        the assertion is positive, but not if it is negative.
419    12. Change 11 fortuitously reduced the size of the stack frame used in the
420        "match()" function of pcre_exec.c by one pointer. Forthcoming
421        implementation of support for (*MARK) will need an extra pointer on the
422        stack; I have reserved it now, so that the stack frame size does not
423        decrease.
425    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
426        item in branch that calls a recursion is a subroutine call - as in the
427        second branch in the above example - was incorrectly given the compile-
428        time error "recursive call could loop indefinitely" because pcre_compile()
429        was not correctly checking the subroutine for matching a non-empty string.
431    14. The checks for overrunning compiling workspace could trigger after an
432        overrun had occurred. This is a "should never occur" error, but it can be
433        triggered by pathological patterns such as hundreds of nested parentheses.
434        The checks now trigger 100 bytes before the end of the workspace.
436    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
439    Version 8.01 19-Jan-2010
440    ------------------------
442    1.  If a pattern contained a conditional subpattern with only one branch (in
443        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
444        computed the wrong minimum data length (which is of course zero for such
445        subpatterns). This could cause incorrect "no match" results.
447    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
448        the pattern is reset in the first branch, pcre_compile() failed with
449        "internal error: code overflow at offset...". This happened only when
450        the reset was to the original external option setting. (An optimization
451        abstracts leading options settings into an external setting, which was the
452        cause of this.)
454    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
455        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
456        assertion pattern did not match (meaning that the assertion was true), it
457        was incorrectly treated as false if the SKIP had been reached during the
458        matching. This also applied to assertions used as conditions.
460    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
461        assertion subpattern, including such a pattern used as a condition,
462        unpredictable results occurred, instead of the error return
465    5.  The C++ GlobalReplace function was not working like Perl for the special
466        situation when an empty string is matched. It now does the fancy magic
467        stuff that is necessary.
469    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
470        removed. (These were left over from very, very early versions of PCRE.)
472    7.  Some cosmetic changes to the code to make life easier when compiling it
473        as part of something else:
475        (a) Change DEBUG to PCRE_DEBUG.
477        (b) In pcre_compile(), rename the member of the "branch_chain" structure
478            called "current" as "current_branch", to prevent a collision with the
479            Linux macro when compiled as a kernel module.
481        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
482            prevent a collision with the Linux macro when compiled as a kernel
483            module.
485    8.  In pcre_compile() there are some checks for integer overflows that used to
486        cast potentially large values to (double). This has been changed to that
487        when building, a check for int64_t is made, and if it is found, it is used
488        instead, thus avoiding the use of floating point arithmetic. (There is no
489        other use of FP in PCRE.) If int64_t is not found, the fallback is to
490        double.
492    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
493        2005 (difference between two addresses compared to an unsigned value).
495    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
496        custom one, because of the following reported problem in Windows:
498          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
499              under Win32.
500          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
501              therefore missing the function definition.
502          - The compiler thus generates a "C" signature for the test function.
503          - The linker fails to find the "C" function.
504          - PCRE fails to configure if asked to do so against libbz2.
506    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
507        messages were output:
509          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
510          rerunning libtoolize, to keep the correct libtool macros in-tree.
511          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
513        I have done both of these things.
515    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
516        most of the time, it *can* run out if it is given a pattern that contains a
517        runaway infinite recursion. I updated the discussion in the pcrestack man
518        page.
520    13. Now that we have gone to the x.xx style of version numbers, the minor
521        version may start with zero. Using 08 or 09 is a bad idea because users
522        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
523        interpreted as invalid octal numbers. I've updated the previous comment in
524        configure.ac, and also added a check that gives an error if 08 or 09 are
525        used.
527    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
528        causing partial matching to fail when the end of the subject matched \W
529        in a UTF-8 pattern where \W was quantified with a minimum of 3.
531    15. There were some discrepancies between the declarations in pcre_internal.h
532        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
533        their definitions. The declarations used "const uschar *" and the
534        definitions used USPTR. Even though USPTR is normally defined as "const
535        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
536        reported that: "This difference in casting confuses some C++ compilers, for
537        example, SunCC recognizes above declarations as different functions and
538        generates broken code for hbpcre." I have changed the declarations to use
539        USPTR.
541    16. GNU libtool is named differently on some systems. The autogen.sh script now
542        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
543        (FreeBSD).
545    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
546        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
547        comment: "Figure out how to create a longlong from a string: strtoll and
548        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
549        instance, but it only takes 2 args instead of 3!"
551    18. A subtle bug concerned with back references has been fixed by a change of
552        specification, with a corresponding code fix. A pattern such as
553        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
554        refers, was giving matches when it shouldn't. For example, xa=xaaa would
555        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
556        same bug. Such groups have to be quantified to be useful, or contained
557        inside another quantified group. (If there's no repetition, the reference
558        can never match.) The problem arises because, having left the group and
559        moved on to the rest of the pattern, a later failure that backtracks into
560        the group uses the captured value from the final iteration of the group
561        rather than the correct earlier one. I have fixed this in PCRE by forcing
562        any group that contains a reference to itself to be an atomic group; that
563        is, there cannot be any backtracking into it once it has completed. This is
564        similar to recursive and subroutine calls.
567    Version 8.00 19-Oct-09
568    ----------------------
570    1.  The table for translating pcre_compile() error codes into POSIX error codes
571        was out-of-date, and there was no check on the pcre_compile() error code
572        being within the table. This could lead to an OK return being given in
573        error.
575    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
576        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
577        in a Windows environment.
579    3.  The pcregrep --count option prints the count for each file even when it is
580        zero, as does GNU grep. However, pcregrep was also printing all files when
581        --files-with-matches was added. Now, when both options are given, it prints
582        counts only for those files that have at least one match. (GNU grep just
583        prints the file name in this circumstance, but including the count seems
584        more useful - otherwise, why use --count?) Also ensured that the
585        combination -clh just lists non-zero counts, with no names.
587    4.  The long form of the pcregrep -F option was incorrectly implemented as
588        --fixed_strings instead of --fixed-strings. This is an incompatible change,
589        but it seems right to fix it, and I didn't think it was worth preserving
590        the old behaviour.
592    5.  The command line items --regex=pattern and --regexp=pattern were not
593        recognized by pcregrep, which required --regex pattern or --regexp pattern
594        (with a space rather than an '='). The man page documented the '=' forms,
595        which are compatible with GNU grep; these now work.
597    6.  No libpcreposix.pc file was created for pkg-config; there was just
598        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
600    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
601        when UCP support is not needed, by modifying the Python script that
602        generates it from Unicode data files. This should not matter if the module
603        is correctly used as a library, but I received one complaint about 50K of
604        unwanted data. My guess is that the person linked everything into his
605        program rather than using a library. Anyway, it does no harm.
607    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
608        was a minimum greater than 1 for a wide character in a possessive
609        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
610        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
611        character. Chaos in the form of incorrect output or a compiling loop could
612        result.
614    9.  The restrictions on what a pattern can contain when partial matching is
615        requested for pcre_exec() have been removed. All patterns can now be
616        partially matched by this function. In addition, if there are at least two
617        slots in the offset vector, the offset of the earliest inspected character
618        for the match and the offset of the end of the subject are set in them when
619        PCRE_ERROR_PARTIAL is returned.
621    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
622        synonymous with PCRE_PARTIAL, for backwards compatibility, and
623        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
624        and may be more useful for multi-segment matching.
626    11. Partial matching with pcre_exec() is now more intuitive. A partial match
627        used to be given if ever the end of the subject was reached; now it is
628        given only if matching could not proceed because another character was
629        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
630        string "Z", which now yields "no match" instead of "partial match". In the
631        case of pcre_dfa_exec(), "no match" is given if every matching path for the
632        final character ended with (*FAIL).
634    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
635        if the pattern had a "must contain" character that was already found in the
636        earlier partial match, unless partial matching was again requested. For
637        example, with the pattern /dog.(body)?/, the "must contain" character is
638        "g". If the first part-match was for the string "dog", restarting with
639        "sbody" failed. This bug has been fixed.
641    13. The string returned by pcre_dfa_exec() after a partial match has been
642        changed so that it starts at the first inspected character rather than the
643        first character of the match. This makes a difference only if the pattern
644        starts with a lookbehind assertion or \b or \B (\K is not supported by
645        pcre_dfa_exec()). It's an incompatible change, but it makes the two
646        matching functions compatible, and I think it's the right thing to do.
648    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
649        so that the demonstration program is easily available in environments where
650        PCRE has not been installed from source.
652    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
653        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
654        library.
656    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
657        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
658        is not the first non-POSIX option to be added. Clearly some people find
659        these options useful.
661    17. If a caller to the POSIX matching function regexec() passes a non-zero
662        value for nmatch with a NULL value for pmatch, the value of
663        nmatch is forced to zero.
665    18. RunGrepTest did not have a test for the availability of the -u option of
666        the diff command, as RunTest does. It now checks in the same way as
667        RunTest, and also checks for the -b option.
669    19. If an odd number of negated classes containing just a single character
670        interposed, within parentheses, between a forward reference to a named
671        subpattern and the definition of the subpattern, compilation crashed with
672        an internal error, complaining that it could not find the referenced
673        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
674        [The bug was that it was starting one character too far in when skipping
675        over the character class, thus treating the ] as data rather than
676        terminating the class. This meant it could skip too much.]
678    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
679        /g option in pcretest when the pattern contains \K, which makes it possible
680        to have an empty string match not at the start, even when the pattern is
681        anchored. Updated pcretest and pcredemo to use this option.
683    21. If the maximum number of capturing subpatterns in a recursion was greater
684        than the maximum at the outer level, the higher number was returned, but
685        with unset values at the outer level. The correct (outer level) value is
686        now given.
688    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
689        PCRE did not set those parentheses (unlike Perl). I have now found a way to
690        make it do so. The string so far is captured, making this feature
691        compatible with Perl.
693    23. The tests have been re-organized, adding tests 11 and 12, to make it
694        possible to check the Perl 5.10 features against Perl 5.10.
696    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
697        pattern matches a fixed length string. PCRE did not allow this; now it
698        does. Neither allows recursion.
700    25. I finally figured out how to implement a request to provide the minimum
701        length of subject string that was needed in order to match a given pattern.
702        (It was back references and recursion that I had previously got hung up
703        on.) This code has now been added to pcre_study(); it finds a lower bound
704        to the length of subject needed. It is not necessarily the greatest lower
705        bound, but using it to avoid searching strings that are too short does give
706        some useful speed-ups. The value is available to calling programs via
707        pcre_fullinfo().
709    26. While implementing 25, I discovered to my embarrassment that pcretest had
710        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
711        study optimizations had never been tested with that matching function.
712        Oops. What is worse, even when it was passed study data, there was a bug in
713        pcre_dfa_exec() that meant it never actually used it. Double oops. There
714        were also very few tests of studied patterns with pcre_dfa_exec().
716    27. If (?| is used to create subpatterns with duplicate numbers, they are now
717        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
718        on the other side of the coin, they are no longer allowed to have different
719        names, because these cannot be distinguished in PCRE, and this has caused
720        confusion. (This is a difference from Perl.)
722    28. When duplicate subpattern names are present (necessarily with different
723        numbers, as required by 27 above), and a test is made by name in a
724        conditional pattern, either for a subpattern having been matched, or for
725        recursion in such a pattern, all the associated numbered subpatterns are
726        tested, and the overall condition is true if the condition is true for any
727        one of them. This is the way Perl works, and is also more like the way
728        testing by number works.
731    Version 7.9 11-Apr-09
732    ---------------------
734    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
735        (pcretest), all targets were linked against these libraries. This included
736        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
737        libraries. This caused unwanted dependencies to be created. This problem
738        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
739        pcretest is linked with readline.
741    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
742        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
743        moved outside it again, because FALSE and TRUE are already defined in AIX,
744        but BOOL is not.
746    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
747        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
749    4.  The pcregrep documentation said spaces were inserted as well as colons (or
750        hyphens) following file names and line numbers when outputting matching
751        lines. This is not true; no spaces are inserted. I have also clarified the
752        wording for the --colour (or --color) option.
754    5.  In pcregrep, when --colour was used with -o, the list of matching strings
755        was not coloured; this is different to GNU grep, so I have changed it to be
756        the same.
758    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
759        each matching line was coloured. Now it goes on to look for further matches
760        of any of the test patterns, which is the same behaviour as GNU grep.
762    7.  A pattern that could match an empty string could cause pcregrep to loop; it
763        doesn't make sense to accept an empty string match in pcregrep, so I have
764        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
765        seems to be how GNU grep behaves.
767    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
768        start or after a newline", because the conditional assertion was not being
769        correctly handled. The rule now is that both the assertion and what follows
770        in the first alternative must satisfy the test.
772    9.  If auto-callout was enabled in a pattern with a conditional group whose
773        condition was an assertion, PCRE could crash during matching, both with
774        pcre_exec() and pcre_dfa_exec().
776    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
777        used for matching.
779    11. Unicode property support in character classes was not working for
780        characters (bytes) greater than 127 when not in UTF-8 mode.
782    12. Added the -M command line option to pcretest.
784    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
786    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
788    16. Added comments and documentation about mis-use of no_arg in the C++
789        wrapper.
791    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
792        from Martin Jerabek that uses macro names for all relevant character and
793        string constants.
795    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
796        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
797        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
798        these, but not everybody uses configure.
800    19. A conditional group that had only one branch was not being correctly
801        recognized as an item that could match an empty string. This meant that an
802        enclosing group might also not be so recognized, causing infinite looping
803        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
804        with the subject "ab", where knowledge that the repeated group can match
805        nothing is needed in order to break the loop.
807    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
808        exec(), but without supplying a callout function, matching went wrong.
810    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
811        leak if the size of the offset vector was greater than 30. When the vector
812        is smaller, the saved offsets during recursion go onto a local stack
813        vector, but for larger vectors malloc() is used. It was failing to free
814        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
815        error, in fact).
817    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
818        heapframe that is used only when UTF-8 support is enabled. This caused no
819        problem, but was untidy.
821    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
822        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
823        included within another project.
825    24. Steven Van Ingelgem's patches to add more options to the CMake support,
826        slightly modified by me:
828          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
829              not building pcregrep.
831          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
832              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
834    25. Forward references, both numeric and by name, in patterns that made use of
835        duplicate group numbers, could behave incorrectly or give incorrect errors,
836        because when scanning forward to find the reference group, PCRE was not
837        taking into account the duplicate group numbers. A pattern such as
838        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
840    26. Changed a few more instances of "const unsigned char *" to USPTR, making
841        the feature of a custom pointer more persuasive (as requested by a user).
843    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
844        pcretest.c, inside #ifndefs, because it seems they are sometimes already
845        pre-defined.
847    28. Added support for (*UTF8) at the start of a pattern.
849    29. Arrange for flags added by the "release type" setting in CMake to be shown
850        in the configuration summary.
853    Version 7.8 05-Sep-08
854    ---------------------
856    1.  Replaced UCP searching code with optimized version as implemented for Ad
857        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
858        stage table and inline lookup instead of a function, giving speed ups of 2
859        to 5 times on some simple patterns that I tested. Permission was given to
860        distribute the MultiStage2.py script that generates the tables (it's not in
861        the tarball, but is in the Subversion repository).
863    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
864        scripts.
866    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
867        a group with a zero qualifier. The result of the study could be incorrect,
868        or the function might crash, depending on the pattern.
870    4.  Caseless matching was not working for non-ASCII characters in back
871        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
872        It now works when Unicode Property Support is available.
874    5.  In pcretest, an escape such as \x{de} in the data was always generating
875        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
876        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
877        truncation.
879    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
881    7.  Added two (int) casts to pcregrep when printing the difference of two
882        pointers, in case they are 64-bit values.
884    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
885        test 2 if it fails.
887    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
888        and a #define of that name to empty if it is not externally set. This is to
889        allow users of MSVC to set it if necessary.
891    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
892        the convenience functions in the pcre_get.c source file.
894    11. An option change at the start of a pattern that had top-level alternatives
895        could cause overwriting and/or a crash. This command provoked a crash in
896        some environments:
898          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
900        This potential security problem was recorded as CVE-2008-2371.
902    12. For a pattern where the match had to start at the beginning or immediately
903        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
904        pcre_dfa_exec() could read past the end of the passed subject if there was
905        no match. To help with detecting such bugs (e.g. with valgrind), I modified
906        pcretest so that it places the subject at the end of its malloc-ed buffer.
908    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
909        exec() might read past the end of the data buffer in UTF-8 mode.
911    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
912        the data contained the byte 0x85 as part of a UTF-8 character within its
913        first line. This applied both to normal and DFA matching.
915    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
916        /^[^d]*?$/8 failed to match "abc".
918    16. Added a missing copyright notice to pcrecpp_internal.h.
920    17. Make it more clear in the documentation that values returned from
921        pcre_exec() in ovector are byte offsets, not character counts.
923    18. Tidied a few places to stop certain compilers from issuing warnings.
925    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
926        supplied by Stefan Weber. I made a further small update for 7.8 because
927        there is a change of source arrangements: the pcre_searchfuncs.c module is
928        replaced by pcre_ucd.c.
931    Version 7.7 07-May-08
932    ---------------------
934    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
935        a string to a long long, pretend we don't even have a long long." This is
936        done by checking for the strtoq, strtoll, and _strtoi64 functions.
938    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
939        pre-7.6 versions, which defined a global no_arg variable instead of putting
940        it in the RE class. (See also #8 below.)
942    3.  Remove a line of dead code, identified by coverity and reported by Nuno
943        Lopes.
945    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
947        (1) The include/exclude patterns were being applied to the whole pathnames
948            of files, instead of just to the final components.
950        (2) If there was more than one level of directory, the subdirectories were
951            skipped unless they satisfied the include/exclude conditions. This is
952            inconsistent with GNU grep (and could even be seen as contrary to the
953            pcregrep specification - which I improved to make it absolutely clear).
954            The action now is always to scan all levels of directory, and just
955            apply the include/exclude patterns to regular files.
957    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
958        --exclude_dir in the tests to avoid scanning .svn directories.
960    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
961        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
962        doesn't support NULs in patterns.
964    7.  Added some missing "const"s to declarations of static tables in
965        pcre_compile.c and pcre_dfa_exec.c.
967    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
968        caused by fix #2  above. (Subsequently also a second patch to fix the
969        first patch. And a third patch - this was a messy problem.)
971    9.  Applied Craig's patch to remove the use of push_back().
973    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
974        matching function regexec().
976    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
977        which, however, unlike Perl's \g{...}, are subroutine calls, not back
978        references. PCRE supports relative numbers with this syntax (I don't think
979        Oniguruma does).
981    12. Previously, a group with a zero repeat such as (...){0} was completely
982        omitted from the compiled regex. However, this means that if the group
983        was called as a subroutine from elsewhere in the pattern, things went wrong
984        (an internal error was given). Such groups are now left in the compiled
985        pattern, with a new opcode that causes them to be skipped at execution
986        time.
988    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
989        to the way PCRE behaves:
991        (a) A lone ] character is dis-allowed (Perl treats it as data).
993        (b) A back reference to an unmatched subpattern matches an empty string
994            (Perl fails the current match path).
996        (c) A data ] in a character class must be notated as \] because if the
997            first data character in a class is ], it defines an empty class. (In
998            Perl it is not possible to have an empty class.) The empty class []
999            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1000            The negative empty class [^] matches any one character, independently
1001            of the DOTALL setting.
1003    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1004        non-existent subpattern following a character class starting with ']' and
1005        containing () gave an internal compiling error instead of "reference to
1006        non-existent subpattern". Fortunately, when the pattern did exist, the
1007        compiled code was correct. (When scanning forwards to check for the
1008        existencd of the subpattern, it was treating the data ']' as terminating
1009        the class, so got the count wrong. When actually compiling, the reference
1010        was subsequently set up correctly.)
1012    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1013        it was being rejected as not supported by pcre_dfa_exec(), even though
1014        other assertions are supported. I have made pcre_dfa_exec() support
1015        (*FAIL).
1017    16. The implementation of 13c above involved the invention of a new opcode,
1018        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1019        cannot be changed at match time, I realized I could make a small
1020        improvement to matching performance by compiling OP_ALLANY instead of
1021        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1022        on the OP_ANY path.
1024    17. Compiling pcretest on Windows with readline support failed without the
1025        following two fixes: (1) Make the unistd.h include conditional on
1026        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1028    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1029        ncurses library to be included for pcretest when ReadLine support is
1030        requested, but also to allow for it to be overridden. This patch came from
1031        Daniel Bergström.
1033    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1034        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1035        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1036        spotting this.
1039    Version 7.6 28-Jan-08
1040    ---------------------
1042    1.  A character class containing a very large number of characters with
1043        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1044        overflow.
1046    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1047        HAVE_LONG_LONG is not defined.
1049    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1050        bring them up to date and include new features. This patch includes:
1052        - Fixed PH's badly added libz and libbz2 support.
1053        - Fixed a problem with static linking.
1054        - Added pcredemo. [But later removed - see 7 below.]
1055        - Fixed dftables problem and added an option.
1056        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1057            HAVE_LONG_LONG.
1058        - Added readline support for pcretest.
1059        - Added an listing of the option settings after cmake has run.
1061    4.  A user submitted a patch to Makefile that makes it easy to create
1062        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1063        Makefile.am that cause it to include this special target, without
1064        affecting anything else. Note that the same mingw target plus all
1065        the other distribution libraries and programs are now supported
1066        when configuring with CMake (see 6 below) instead of with
1067        Configure/Make.
1069    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1070        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1071        exported in the Windows port". It has not yet been confirmed that the patch
1072        solves the problem, but it does no harm.
1074    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1075        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1076        with CMake, and also correct the comment about stack recursion.
1078    7.  Remove the automatic building of pcredemo from the ./configure system and
1079        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1080        of a program that users should build themselves after PCRE is installed, so
1081        building it automatically is not really right. What is more, it gave
1082        trouble in some build environments.
1084    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1087    Version 7.5 10-Jan-08
1088    ---------------------
1090    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1091        values in parens when parsing an RE using the C++ wrapper."
1093    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1094        Characters greater than 255 were excluded from the class instead of being
1095        included.
1097    3.  The same bug as (2) above applied to negated POSIX classes such as
1098        [:^space:].
1100    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1101        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1102        I have changed it.
1104    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1105        first named subpattern) and a construct such as (?&a) would reference the
1106        first named subpattern whose name started with "a" (in other words, the
1107        length check was missing). Both these problems are fixed. "Subpattern name
1108        expected" is now given for (?&) (a zero-length name), and this patch also
1109        makes it give the same error for \k'' (previously it complained that that
1110        was a reference to a non-existent subpattern).
1112    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1113        this is right because (?- can be followed by option settings as well as by
1114        digits. I have, however, made the messages clearer.
1116    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1117        than the number used in the conditional) now cause a compile-time error.
1118        This is actually not compatible with Perl, which accepts such patterns, but
1119        treats the conditional as always being FALSE (as PCRE used to), but it
1120        seems to me that giving a diagnostic is better.
1122    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1123        and messages.
1125    9.  Fix two occurrences of "backslash" in comments that should have been
1126        "backspace".
1128    10. Remove two redundant lines of code that can never be obeyed (their function
1129        was moved elsewhere).
1131    11. The program that makes PCRE's Unicode character property table had a bug
1132        which caused it to generate incorrect table entries for sequences of
1133        characters that have the same character type, but are in different scripts.
1134        It amalgamated them into a single range, with the script of the first of
1135        them. In other words, some characters were in the wrong script. There were
1136        thirteen such cases, affecting characters in the following ranges:
1138          U+002b0 - U+002c1
1139          U+0060c - U+0060d
1140          U+0061e - U+00612
1141          U+0064b - U+0065e
1142          U+0074d - U+0076d
1143          U+01800 - U+01805
1144          U+01d00 - U+01d77
1145          U+01d9b - U+01dbf
1146          U+0200b - U+0200f
1147          U+030fc - U+030fe
1148          U+03260 - U+0327f
1149          U+0fb46 - U+0fbb1
1150          U+10450 - U+1049d
1152    12. The -o option (show only the matching part of a line) for pcregrep was not
1153        compatible with GNU grep in that, if there was more than one match in a
1154        line, it showed only the first of them. It now behaves in the same way as
1155        GNU grep.
1157    13. If the -o and -v options were combined for pcregrep, it printed a blank
1158        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1159        does the same. The return code can be used to tell if there were any
1160        non-matching lines.
1162    14. Added --file-offsets and --line-offsets to pcregrep.
1164    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1165        infinitely looping recursion. The bug was that positive lookaheads were not
1166        being skipped when checking for a possible empty match (negative lookaheads
1167        and both kinds of lookbehind were skipped).
1169    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1170        inclusion of <windows.h> to before rather than after the definition of
1171        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1173    17. Specifying a possessive quantifier with a specific limit for a Unicode
1174        character property caused pcre_compile() to compile bad code, which led at
1175        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1176        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1177        caused the error; without that there was no problem.
1179    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1181    19. Added --enable-pcretest-libreadline.
1183    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1184        RE::GlobalReplace(). As a result, the number of replacements returned was
1185        double what it should be. I removed one of the increments, but Craig sent a
1186        later patch that removed the other one (the right fix) and added unit tests
1187        that check the return values (which was not done before).
1189    21. Several CMake things:
1191        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1192            the names libpcre and libpcreposix, not just pcre and pcreposix.
1194        (2) The above change means that pcretest and pcregrep are now correctly
1195            linked with the newly-built libraries, not previously installed ones.
1199    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1200        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1201        UTF-8 newline character). The key issue is that the pattern starts .*;
1202        this means that the match must be either at the beginning, or after a
1203        newline. The bug was in the code for advancing after a failed match and
1204        checking that the new position followed a newline. It was not taking
1205        account of UTF-8 characters correctly.
1207    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1208        character classes. PCRE was not treating the sequence [:...:] as a
1209        character class unless the ... were all letters. Perl, however, seems to
1210        allow any characters between [: and :], though of course it rejects as
1211        unknown any "names" that contain non-letters, because all the known class
1212        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1213        for example, whereas PCRE did not - it did not recognize a POSIX character
1214        class. This seemed a bit dangerous, so the code has been changed to be
1215        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1216        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1217        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1218        Perl does, and where it didn't before.
1220    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1221        Windows environments %n is disabled by default.
1224    Version 7.4 21-Sep-07
1225    ---------------------
1227    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1228        means that a class such as [\s] counted as "explicit reference to CR or
1229        LF". That isn't really right - the whole point of the change was to try to
1230        help when there was an actual mention of one of the two characters. So now
1231        the change happens only if \r or \n (or a literal CR or LF) character is
1232        encountered.
1234    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1235        of both had grown to the point where there were only 3 bits left.
1236        Fortunately, there was spare space in the data structure, and so I have
1237        moved the internal flags into a new 16-bit field to free up more option
1238        bits.
1240    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1241        but did not set the internal JCHANGED flag - either of these is enough to
1242        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1243        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1244        start sets both bits.
1246    4.  Added options (at build time, compile time, exec time) to change \R from
1247        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1249    5.  doc/pcresyntax.html was missing from the distribution.
1251    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1252        compatibility, even though it is no longer used.
1254    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1255        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1256        windows.h file is present (where different names are used). [This was
1257        reversed later after testing - see 16 below.]
1259    8.  Changed all #include <config.h> to #include "config.h". There were also
1260        some further <pcre.h> cases that I changed to "pcre.h".
1262    9.  When pcregrep was used with the --colour option, it missed the line ending
1263        sequence off the lines that it output.
1265    10. It was pointed out to me that arrays of string pointers cause lots of
1266        relocations when a shared library is dynamically loaded. A technique of
1267        using a single long string with a table of offsets can drastically reduce
1268        these. I have refactored PCRE in four places to do this. The result is
1269        dramatic:
1271          Originally:                          290
1272          After changing UCP table:            187
1273          After changing error message table:   43
1274          After changing table of "verbs"       36
1275          After changing table of Posix names   22
1277        Thanks to the folks working on Gregex for glib for this insight.
1279    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1280        unicode-properties was also set.
1282    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1284    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1285        checked only for CRLF.
1287    14. Added casts to pcretest.c to avoid compiler warnings.
1289    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1291    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1292        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1293        entirely. This removes changes made in 7 above.
1295    17. The CMake files have been updated, and there is now more information about
1296        building with CMake in the NON-UNIX-USE document.
1299    Version 7.3 28-Aug-07
1300    ---------------------
1302     1. In the rejigging of the build system that eventually resulted in 7.1, the
1303        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1304        brackets there is not right, since it causes compilers to look for an
1305        installed pcre.h, not the version that is in the source that is being
1306        compiled (which of course may be different). I have changed it back to:
1308          #include "pcre.h"
1310        I have a vague recollection that the change was concerned with compiling in
1311        different directories, but in the new build system, that is taken care of
1312        by the VPATH setting the Makefile.
1314     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1315        when the subject happened to end in the byte 0x85 (e.g. if the last
1316        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1317        characters but of course it shouldn't be taken as a newline when it is part
1318        of another character. The bug was that, for an unlimited repeat of . in
1319        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1320        characters when looking for a newline.
1322     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1324     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1325        in debug output.
1327     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1328        long printing in the pcrecpp unittest when running under MinGW.
1330     6. ESC_K was left out of the EBCDIC table.
1332     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1333        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1334        limit also applies to "virtual nesting" when a pattern is recursive, and in
1335        this case 1000 isn't so big. I have been able to remove this limit at the
1336        expense of backing off one optimization in certain circumstances. Normally,
1337        when pcre_exec() would call its internal match() function recursively and
1338        immediately return the result unconditionally, it uses a "tail recursion"
1339        feature to save stack. However, when a subpattern that can match an empty
1340        string has an unlimited repetition quantifier, it no longer makes this
1341        optimization. That gives it a stack frame in which to save the data for
1342        checking that an empty string has been matched. Previously this was taken
1343        from the 1000-entry workspace that had been reserved. So now there is no
1344        explicit limit, but more stack is used.
1346     8. Applied Daniel's patches to solve problems with the import/export magic
1347        syntax that is required for Windows, and which was going wrong for the
1348        pcreposix and pcrecpp parts of the library. These were overlooked when this
1349        problem was solved for the main library.
1351     9. There were some crude static tests to avoid integer overflow when computing
1352        the size of patterns that contain repeated groups with explicit upper
1353        limits. As the maximum quantifier is 65535, the maximum group length was
1354        set at 30,000 so that the product of these two numbers did not overflow a
1355        32-bit integer. However, it turns out that people want to use groups that
1356        are longer than 30,000 bytes (though not repeat them that many times).
1357        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1358        made it possible to implement the integer overflow checks in a much more
1359        dynamic way, which I have now done. The artificial limitation on group
1360        length has been removed - we now have only the limit on the total length of
1361        the compiled pattern, which depends on the LINK_SIZE setting.
1363    10. Fixed a bug in the documentation for get/copy named substring when
1364        duplicate names are permitted. If none of the named substrings are set, the
1365        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1366        empty string.
1368    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1369        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1370        because the ] is interpreted as the first data character and the
1371        terminating ] is not found. PCRE has been made compatible with Perl in this
1372        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1373        cause memory overwriting.
1375    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1376        string has been matched (to stop an infinite loop). It was not recognizing
1377        a conditional subpattern that could match an empty string if that
1378        subpattern was within another subpattern. For example, it looped when
1379        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1380        condition was not nested. This bug has been fixed.
1382    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1383        past the start of the subject in the presence of bytes with the top bit
1384        set, for example "\x8aBCD".
1386    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1387        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1389    14. Optimized (?!) to (*FAIL).
1391    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1392        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1393        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1394        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1395        does: it's just the validity check that is more restrictive.
1397    16. Inserted checks for integer overflows during escape sequence (backslash)
1398        processing, and also fixed erroneous offset values for syntax errors during
1399        backslash processing.
1401    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1402        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1404    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1405        caused an overrun.
1407    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1408        something other than just ASCII characters) inside a group that had an
1409        unlimited repeat caused a loop at compile time (while checking to see
1410        whether the group could match an empty string).
1412    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1413        [\P{Any}] did so. (Error in the code for printing property names.)
1415    21. An orphan \E inside a character class could cause a crash.
1417    22. A repeated capturing bracket such as (A)? could cause a wild memory
1418        reference during compilation.
1420    23. There are several functions in pcre_compile() that scan along a compiled
1421        expression for various reasons (e.g. to see if it's fixed length for look
1422        behind). There were bugs in these functions when a repeated \p or \P was
1423        present in the pattern. These operators have additional parameters compared
1424        with \d, etc, and these were not being taken into account when moving along
1425        the compiled data. Specifically:
1427        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1428            length.
1430        (b) An item such as \pL+ within a repeated group could cause crashes or
1431            loops.
1433        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1434            "reference to non-existent subpattern" error.
1436        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1438    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1439        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1441    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1443    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1444        character were causing crashes (broken optimization).
1446    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1447        \p or \P) caused a compile-time loop.
1449    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1450        break. For example, the unstudied pattern [\r\n]A does not match the string
1451        "\r\nA" because change 7.0/46 below moves the current point on by two
1452        characters after failing to match at the start. However, the pattern \nA
1453        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1454        the same is true. There doesn't seem any very clean way out of this, but
1455        what I have chosen to do makes the common cases work: PCRE now takes note
1456        of whether there can be an explicit match for \r or \n anywhere in the
1457        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1458        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1459        pattern has explicit CR or LF references.
1461    29. Added (*CR) etc for changing newline setting at start of pattern.
1464    Version 7.2 19-Jun-07
1465  ---------------------  ---------------------
1467   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 1481  Version 7.2 01-May-07
1481      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
1482      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
1483      in all cases.      in all cases.
1485   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
1487      (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
1488          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
1490      (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
1491          to be opened parentheses.          to be opened parentheses.
1493      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
1494          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
1496      (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
1497          is not part of it.          is not part of it.
1499        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1501        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1502            reference syntax.
1504        (g) (?| introduces a group in which the numbering of parentheses in each
1505            alternative starts with the same number.
1507        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1509     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1512     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1513        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1514        for detecting groups that can match an empty string.
1516     9. A pattern with a very large number of alternatives (more than several
1517        hundred) was running out of internal workspace during the pre-compile
1518        phase, where pcre_compile() figures out how much memory will be needed. A
1519        bit of new cunning has reduced the workspace needed for groups with
1520        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1521        workspace instead of running out of the 4096 that are available.
1523    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1525    11. Applied patch from Google to remove an optimization that didn't quite work.
1526        The report of the bug said:
1528          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1529          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1530          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1532    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1533        it matched the wrong number of bytes.
1536  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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