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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.1 05-Mar-07  Version 8.12 11-Jan-2011
5    ------------------------
7    1.  Fixed some typos in the markup of the man pages, and wrote a script that
8        checks for such things as part of the documentation building process.
11    Version 8.11 10-Dec-2010
12    ------------------------
14    1.  (*THEN) was not working properly if there were untried alternatives prior
15        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
16        backtracked to try for "b" instead of moving to the next alternative branch
17        at the same level (in this case, to look for "c"). The Perl documentation
18        is clear that when (*THEN) is backtracked onto, it goes to the "next
19        alternative in the innermost enclosing group".
21    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
22        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
23        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
24        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
25        (*THEN).
27    3.  If \s appeared in a character class, it removed the VT character from
28        the class, even if it had been included by some previous item, for example
29        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
30        of \s, but is part of the POSIX "space" class.)
32    4.  A partial match never returns an empty string (because you can always
33        match an empty string at the end of the subject); however the checking for
34        an empty string was starting at the "start of match" point. This has been
35        changed to the "earliest inspected character" point, because the returned
36        data for a partial match starts at this character. This means that, for
37        example, /(?<=abc)def/ gives a partial match for the subject "abc"
38        (previously it gave "no match").
40    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
41        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
42        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
43        has an implication that the given string is incomplete (because a partial
44        match is preferred over a full match). For this reason, these items now
45        give a partial match in this situation. [Aside: previously, the one case
46        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
47        match rather than a full match, which was wrong by the old rules, but is
48        now correct.]
50    6.  There was a bug in the handling of #-introduced comments, recognized when
51        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
52        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
53        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
54        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
55        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
56        places in pcre_compile().
58    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
59        comments when looking ahead for named forward references to subpatterns,
60        the only newline sequence it recognized was NL. It now handles newlines
61        according to the set newline convention.
63    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
64        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
65        cater for a lack of strerror(). These oversights have been fixed.
67    9.  Added --match-limit and --recursion-limit to pcregrep.
69    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
71    11. When the -o option was used, pcregrep was setting a return code of 1, even
72        when matches were found, and --line-buffered was not being honoured.
74    12. Added an optional parentheses number to the -o and --only-matching options
75        of pcregrep.
77    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
78        can match an empty string. The code to do it in pcretest and pcredemo
79        needed fixing:
81        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
82            only one byte after an empty string match just before CRLF (this case
83            just got forgotten; "any" and "anycrlf" were OK).
85        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
86            mode when an empty string match preceded an ASCII character followed by
87            a non-ASCII character. (The code for advancing by one character rather
88            than one byte was nonsense.)
90        (c) The pcredemo.c sample program did not have any code at all to handle
91            the cases when CRLF is a valid newline sequence.
93    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
94        as a starting offset was within the subject string. There is now a new
95        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
96        negative or greater than the length of the string. In order to test this,
97        pcretest is extended to allow the setting of negative starting offsets.
99    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
100        starting offset points to the beginning of a UTF-8 character was
101        unnecessarily clumsy. I tidied it up.
103    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
104        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
106    17. Nobody had reported that the --include_dir option, which was added in
107        release 7.7 should have been called --include-dir (hyphen, not underscore)
108        for compatibility with GNU grep. I have changed it to --include-dir, but
109        left --include_dir as an undocumented synonym, and the same for
110        --exclude-dir, though that is not available in GNU grep, at least as of
111        release 2.5.4.
113    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
114        characters from a string of bytes) have been redefined so as not to use
115        loops, in order to improve performance in some environments. At the same
116        time, I abstracted some of the common code into auxiliary macros to save
117        repetition (this should not affect the compiled code).
119    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
120        compile-time error is now given if \c is not followed by an ASCII
121        character, that is, a byte less than 128. (In EBCDIC mode, the code is
122        different, and any byte value is allowed.)
124    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
125        START_OPTIMIZE option, which is now allowed at compile time - but just
126        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
127        to pcregrep and other applications that have no direct access to PCRE
128        options. The new /Y option in pcretest sets this option when calling
129        pcre_compile().
131    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
132        back references. Groups containing recursive back references were forced to
133        be atomic by that change, but in the case of named groups, the amount of
134        memory required was incorrectly computed, leading to "Failed: internal
135        error: code overflow". This has been fixed.
137    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
138        pcretest.c, to avoid build problems in some Borland environments.
141    Version 8.10 25-Jun-2010
142    ------------------------
144    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
145        THEN.
147    2.  (*ACCEPT) was not working when inside an atomic group.
149    3.  Inside a character class, \B is treated as a literal by default, but
150        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
151        causes the error). The code is unchanged, but I tidied the documentation.
153    4.  Inside a character class, PCRE always treated \R and \X as literals,
154        whereas Perl faults them if its -w option is set. I have changed PCRE so
155        that it faults them when PCRE_EXTRA is set.
157    5.  Added support for \N, which always matches any character other than
158        newline. (It is the same as "." when PCRE_DOTALL is not set.)
160    6.  When compiling pcregrep with newer versions of gcc which may have
161        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
162        declared with attribute warn_unused_result" were given. Just casting the
163        result to (void) does not stop the warnings; a more elaborate fudge is
164        needed. I've used a macro to implement this.
166    7.  Minor change to pcretest.c to avoid a compiler warning.
168    8.  Added four artifical Unicode properties to help with an option to make
169        \s etc use properties (see next item). The new properties are: Xan
170        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
172    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
173        use Unicode properties. (*UCP) at the start of a pattern can be used to set
174        this option. Modified pcretest to add /W to test this facility. Added
175        REG_UCP to make it available via the POSIX interface.
177    10. Added --line-buffered to pcregrep.
179    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
180        studied, and the match started with a letter with a code point greater than
181        127 whose first byte was different to the first byte of the other case of
182        the letter, the other case of this starting letter was not recognized
183        (#976).
185    12. If a pattern that was studied started with a repeated Unicode property
186        test, for example, \p{Nd}+, there was the theoretical possibility of
187        setting up an incorrect bitmap of starting bytes, but fortunately it could
188        not have actually happened in practice until change 8 above was made (it
189        added property types that matched character-matching opcodes).
191    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
192        possible starting bytes for non-anchored patterns.
194    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
195        \R, and also a number of cases that involve Unicode properties, both
196        explicit and implicit when PCRE_UCP is set.
198    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
199        input, it could crash or give wrong results if characters with values
200        greater than 0xc0 were present in the subject string. (Detail: it assumed
201        UTF-8 input when processing these items.)
203    16. Added a lot of (int) casts to avoid compiler warnings in systems where
204        size_t is 64-bit (#991).
206    17. Added a check for running out of memory when PCRE is compiled with
207        --disable-stack-for-recursion (#990).
209    18. If the last data line in a file for pcretest does not have a newline on
210        the end, a newline was missing in the output.
212    19. The default pcre_chartables.c file recognizes only ASCII characters (values
213        less than 128) in its various bitmaps. However, there is a facility for
214        generating tables according to the current locale when PCRE is compiled. It
215        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
216        characters, are recognized by isspace() and therefore were getting set in
217        these tables, and indeed these tables seem to approximate to ISO 8859. This
218        caused a problem in UTF-8 mode when pcre_study() was used to create a list
219        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
220        which of course cannot start UTF-8 characters. I have changed the code so
221        that only real ASCII characters (less than 128) and the correct starting
222        bytes for UTF-8 encodings are set for characters greater than 127 when in
223        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
224        altogether.)
226    20. Added the /T option to pcretest so as to be able to run tests with non-
227        standard character tables, thus making it possible to include the tests
228        used for 19 above in the standard set of tests.
230    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
231        reference to a subpattern the other side of a comment that contains an
232        opening parenthesis caused either an internal compiling error, or a
233        reference to the wrong subpattern.
236    Version 8.02 19-Mar-2010
237    ------------------------
239    1.  The Unicode data tables have been updated to Unicode 5.2.0.
241    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
242        configured.
244    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
245        original author of that file, following a query about its status.
247    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
248        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
250    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
251        quantifier applied to a forward-referencing subroutine call, could compile
252        incorrect code or give the error "internal error: previously-checked
253        referenced subpattern not found".
255    6.  Both MS Visual Studio and Symbian OS have problems with initializing
256        variables to point to external functions. For these systems, therefore,
257        pcre_malloc etc. are now initialized to local functions that call the
258        relevant global functions.
260    7.  There were two entries missing in the vectors called coptable and poptable
261        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
262        I've fixed the data, and added a kludgy way of testing at compile time that
263        the lengths are correct (equal to the number of opcodes).
265    8.  Following on from 7, I added a similar kludge to check the length of the
266        eint vector in pcreposix.c.
268    9.  Error texts for pcre_compile() are held as one long string to avoid too
269        much relocation at load time. To find a text, the string is searched,
270        counting zeros. There was no check for running off the end of the string,
271        which could happen if a new error number was added without updating the
272        string.
274    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
276    11. \K was not working if it appeared in an atomic group or in a group that
277        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
278        \K is "not well defined" if used in an assertion. PCRE now accepts it if
279        the assertion is positive, but not if it is negative.
281    12. Change 11 fortuitously reduced the size of the stack frame used in the
282        "match()" function of pcre_exec.c by one pointer. Forthcoming
283        implementation of support for (*MARK) will need an extra pointer on the
284        stack; I have reserved it now, so that the stack frame size does not
285        decrease.
287    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
288        item in branch that calls a recursion is a subroutine call - as in the
289        second branch in the above example - was incorrectly given the compile-
290        time error "recursive call could loop indefinitely" because pcre_compile()
291        was not correctly checking the subroutine for matching a non-empty string.
293    14. The checks for overrunning compiling workspace could trigger after an
294        overrun had occurred. This is a "should never occur" error, but it can be
295        triggered by pathological patterns such as hundreds of nested parentheses.
296        The checks now trigger 100 bytes before the end of the workspace.
298    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
301    Version 8.01 19-Jan-2010
302    ------------------------
304    1.  If a pattern contained a conditional subpattern with only one branch (in
305        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
306        computed the wrong minimum data length (which is of course zero for such
307        subpatterns). This could cause incorrect "no match" results.
309    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
310        the pattern is reset in the first branch, pcre_compile() failed with
311        "internal error: code overflow at offset...". This happened only when
312        the reset was to the original external option setting. (An optimization
313        abstracts leading options settings into an external setting, which was the
314        cause of this.)
316    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
317        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
318        assertion pattern did not match (meaning that the assertion was true), it
319        was incorrectly treated as false if the SKIP had been reached during the
320        matching. This also applied to assertions used as conditions.
322    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
323        assertion subpattern, including such a pattern used as a condition,
324        unpredictable results occurred, instead of the error return
327    5.  The C++ GlobalReplace function was not working like Perl for the special
328        situation when an empty string is matched. It now does the fancy magic
329        stuff that is necessary.
331    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
332        removed. (These were left over from very, very early versions of PCRE.)
334    7.  Some cosmetic changes to the code to make life easier when compiling it
335        as part of something else:
337        (a) Change DEBUG to PCRE_DEBUG.
339        (b) In pcre_compile(), rename the member of the "branch_chain" structure
340            called "current" as "current_branch", to prevent a collision with the
341            Linux macro when compiled as a kernel module.
343        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
344            prevent a collision with the Linux macro when compiled as a kernel
345            module.
347    8.  In pcre_compile() there are some checks for integer overflows that used to
348        cast potentially large values to (double). This has been changed to that
349        when building, a check for int64_t is made, and if it is found, it is used
350        instead, thus avoiding the use of floating point arithmetic. (There is no
351        other use of FP in PCRE.) If int64_t is not found, the fallback is to
352        double.
354    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
355        2005 (difference between two addresses compared to an unsigned value).
357    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
358        custom one, because of the following reported problem in Windows:
360          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
361              under Win32.
362          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
363              therefore missing the function definition.
364          - The compiler thus generates a "C" signature for the test function.
365          - The linker fails to find the "C" function.
366          - PCRE fails to configure if asked to do so against libbz2.
368    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
369        messages were output:
371          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
372          rerunning libtoolize, to keep the correct libtool macros in-tree.
373          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
375        I have done both of these things.
377    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
378        most of the time, it *can* run out if it is given a pattern that contains a
379        runaway infinite recursion. I updated the discussion in the pcrestack man
380        page.
382    13. Now that we have gone to the x.xx style of version numbers, the minor
383        version may start with zero. Using 08 or 09 is a bad idea because users
384        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
385        interpreted as invalid octal numbers. I've updated the previous comment in
386        configure.ac, and also added a check that gives an error if 08 or 09 are
387        used.
389    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
390        causing partial matching to fail when the end of the subject matched \W
391        in a UTF-8 pattern where \W was quantified with a minimum of 3.
393    15. There were some discrepancies between the declarations in pcre_internal.h
394        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
395        their definitions. The declarations used "const uschar *" and the
396        definitions used USPTR. Even though USPTR is normally defined as "const
397        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
398        reported that: "This difference in casting confuses some C++ compilers, for
399        example, SunCC recognizes above declarations as different functions and
400        generates broken code for hbpcre." I have changed the declarations to use
401        USPTR.
403    16. GNU libtool is named differently on some systems. The autogen.sh script now
404        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
405        (FreeBSD).
407    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
408        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
409        comment: "Figure out how to create a longlong from a string: strtoll and
410        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
411        instance, but it only takes 2 args instead of 3!"
413    18. A subtle bug concerned with back references has been fixed by a change of
414        specification, with a corresponding code fix. A pattern such as
415        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
416        refers, was giving matches when it shouldn't. For example, xa=xaaa would
417        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
418        same bug. Such groups have to be quantified to be useful, or contained
419        inside another quantified group. (If there's no repetition, the reference
420        can never match.) The problem arises because, having left the group and
421        moved on to the rest of the pattern, a later failure that backtracks into
422        the group uses the captured value from the final iteration of the group
423        rather than the correct earlier one. I have fixed this in PCRE by forcing
424        any group that contains a reference to itself to be an atomic group; that
425        is, there cannot be any backtracking into it once it has completed. This is
426        similar to recursive and subroutine calls.
429    Version 8.00 19-Oct-09
430    ----------------------
432    1.  The table for translating pcre_compile() error codes into POSIX error codes
433        was out-of-date, and there was no check on the pcre_compile() error code
434        being within the table. This could lead to an OK return being given in
435        error.
437    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
438        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
439        in a Windows environment.
441    3.  The pcregrep --count option prints the count for each file even when it is
442        zero, as does GNU grep. However, pcregrep was also printing all files when
443        --files-with-matches was added. Now, when both options are given, it prints
444        counts only for those files that have at least one match. (GNU grep just
445        prints the file name in this circumstance, but including the count seems
446        more useful - otherwise, why use --count?) Also ensured that the
447        combination -clh just lists non-zero counts, with no names.
449    4.  The long form of the pcregrep -F option was incorrectly implemented as
450        --fixed_strings instead of --fixed-strings. This is an incompatible change,
451        but it seems right to fix it, and I didn't think it was worth preserving
452        the old behaviour.
454    5.  The command line items --regex=pattern and --regexp=pattern were not
455        recognized by pcregrep, which required --regex pattern or --regexp pattern
456        (with a space rather than an '='). The man page documented the '=' forms,
457        which are compatible with GNU grep; these now work.
459    6.  No libpcreposix.pc file was created for pkg-config; there was just
460        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
462    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
463        when UCP support is not needed, by modifying the Python script that
464        generates it from Unicode data files. This should not matter if the module
465        is correctly used as a library, but I received one complaint about 50K of
466        unwanted data. My guess is that the person linked everything into his
467        program rather than using a library. Anyway, it does no harm.
469    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
470        was a minimum greater than 1 for a wide character in a possessive
471        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
472        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
473        character. Chaos in the form of incorrect output or a compiling loop could
474        result.
476    9.  The restrictions on what a pattern can contain when partial matching is
477        requested for pcre_exec() have been removed. All patterns can now be
478        partially matched by this function. In addition, if there are at least two
479        slots in the offset vector, the offset of the earliest inspected character
480        for the match and the offset of the end of the subject are set in them when
481        PCRE_ERROR_PARTIAL is returned.
483    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
484        synonymous with PCRE_PARTIAL, for backwards compatibility, and
485        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
486        and may be more useful for multi-segment matching.
488    11. Partial matching with pcre_exec() is now more intuitive. A partial match
489        used to be given if ever the end of the subject was reached; now it is
490        given only if matching could not proceed because another character was
491        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
492        string "Z", which now yields "no match" instead of "partial match". In the
493        case of pcre_dfa_exec(), "no match" is given if every matching path for the
494        final character ended with (*FAIL).
496    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
497        if the pattern had a "must contain" character that was already found in the
498        earlier partial match, unless partial matching was again requested. For
499        example, with the pattern /dog.(body)?/, the "must contain" character is
500        "g". If the first part-match was for the string "dog", restarting with
501        "sbody" failed. This bug has been fixed.
503    13. The string returned by pcre_dfa_exec() after a partial match has been
504        changed so that it starts at the first inspected character rather than the
505        first character of the match. This makes a difference only if the pattern
506        starts with a lookbehind assertion or \b or \B (\K is not supported by
507        pcre_dfa_exec()). It's an incompatible change, but it makes the two
508        matching functions compatible, and I think it's the right thing to do.
510    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
511        so that the demonstration program is easily available in environments where
512        PCRE has not been installed from source.
514    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
515        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
516        library.
518    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
519        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
520        is not the first non-POSIX option to be added. Clearly some people find
521        these options useful.
523    17. If a caller to the POSIX matching function regexec() passes a non-zero
524        value for nmatch with a NULL value for pmatch, the value of
525        nmatch is forced to zero.
527    18. RunGrepTest did not have a test for the availability of the -u option of
528        the diff command, as RunTest does. It now checks in the same way as
529        RunTest, and also checks for the -b option.
531    19. If an odd number of negated classes containing just a single character
532        interposed, within parentheses, between a forward reference to a named
533        subpattern and the definition of the subpattern, compilation crashed with
534        an internal error, complaining that it could not find the referenced
535        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
536        [The bug was that it was starting one character too far in when skipping
537        over the character class, thus treating the ] as data rather than
538        terminating the class. This meant it could skip too much.]
540    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
541        /g option in pcretest when the pattern contains \K, which makes it possible
542        to have an empty string match not at the start, even when the pattern is
543        anchored. Updated pcretest and pcredemo to use this option.
545    21. If the maximum number of capturing subpatterns in a recursion was greater
546        than the maximum at the outer level, the higher number was returned, but
547        with unset values at the outer level. The correct (outer level) value is
548        now given.
550    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
551        PCRE did not set those parentheses (unlike Perl). I have now found a way to
552        make it do so. The string so far is captured, making this feature
553        compatible with Perl.
555    23. The tests have been re-organized, adding tests 11 and 12, to make it
556        possible to check the Perl 5.10 features against Perl 5.10.
558    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
559        pattern matches a fixed length string. PCRE did not allow this; now it
560        does. Neither allows recursion.
562    25. I finally figured out how to implement a request to provide the minimum
563        length of subject string that was needed in order to match a given pattern.
564        (It was back references and recursion that I had previously got hung up
565        on.) This code has now been added to pcre_study(); it finds a lower bound
566        to the length of subject needed. It is not necessarily the greatest lower
567        bound, but using it to avoid searching strings that are too short does give
568        some useful speed-ups. The value is available to calling programs via
569        pcre_fullinfo().
571    26. While implementing 25, I discovered to my embarrassment that pcretest had
572        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
573        study optimizations had never been tested with that matching function.
574        Oops. What is worse, even when it was passed study data, there was a bug in
575        pcre_dfa_exec() that meant it never actually used it. Double oops. There
576        were also very few tests of studied patterns with pcre_dfa_exec().
578    27. If (?| is used to create subpatterns with duplicate numbers, they are now
579        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
580        on the other side of the coin, they are no longer allowed to have different
581        names, because these cannot be distinguished in PCRE, and this has caused
582        confusion. (This is a difference from Perl.)
584    28. When duplicate subpattern names are present (necessarily with different
585        numbers, as required by 27 above), and a test is made by name in a
586        conditional pattern, either for a subpattern having been matched, or for
587        recursion in such a pattern, all the associated numbered subpatterns are
588        tested, and the overall condition is true if the condition is true for any
589        one of them. This is the way Perl works, and is also more like the way
590        testing by number works.
593    Version 7.9 11-Apr-09
594    ---------------------
596    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
597        (pcretest), all targets were linked against these libraries. This included
598        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
599        libraries. This caused unwanted dependencies to be created. This problem
600        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
601        pcretest is linked with readline.
603    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
604        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
605        moved outside it again, because FALSE and TRUE are already defined in AIX,
606        but BOOL is not.
608    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
609        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
611    4.  The pcregrep documentation said spaces were inserted as well as colons (or
612        hyphens) following file names and line numbers when outputting matching
613        lines. This is not true; no spaces are inserted. I have also clarified the
614        wording for the --colour (or --color) option.
616    5.  In pcregrep, when --colour was used with -o, the list of matching strings
617        was not coloured; this is different to GNU grep, so I have changed it to be
618        the same.
620    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
621        each matching line was coloured. Now it goes on to look for further matches
622        of any of the test patterns, which is the same behaviour as GNU grep.
624    7.  A pattern that could match an empty string could cause pcregrep to loop; it
625        doesn't make sense to accept an empty string match in pcregrep, so I have
626        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
627        seems to be how GNU grep behaves.
629    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
630        start or after a newline", because the conditional assertion was not being
631        correctly handled. The rule now is that both the assertion and what follows
632        in the first alternative must satisfy the test.
634    9.  If auto-callout was enabled in a pattern with a conditional group whose
635        condition was an assertion, PCRE could crash during matching, both with
636        pcre_exec() and pcre_dfa_exec().
638    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
639        used for matching.
641    11. Unicode property support in character classes was not working for
642        characters (bytes) greater than 127 when not in UTF-8 mode.
644    12. Added the -M command line option to pcretest.
646    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
648    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
650    16. Added comments and documentation about mis-use of no_arg in the C++
651        wrapper.
653    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
654        from Martin Jerabek that uses macro names for all relevant character and
655        string constants.
657    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
658        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
659        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
660        these, but not everybody uses configure.
662    19. A conditional group that had only one branch was not being correctly
663        recognized as an item that could match an empty string. This meant that an
664        enclosing group might also not be so recognized, causing infinite looping
665        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
666        with the subject "ab", where knowledge that the repeated group can match
667        nothing is needed in order to break the loop.
669    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
670        exec(), but without supplying a callout function, matching went wrong.
672    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
673        leak if the size of the offset vector was greater than 30. When the vector
674        is smaller, the saved offsets during recursion go onto a local stack
675        vector, but for larger vectors malloc() is used. It was failing to free
676        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
677        error, in fact).
679    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
680        heapframe that is used only when UTF-8 support is enabled. This caused no
681        problem, but was untidy.
683    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
684        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
685        included within another project.
687    24. Steven Van Ingelgem's patches to add more options to the CMake support,
688        slightly modified by me:
690          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
691              not building pcregrep.
693          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
694              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
696    25. Forward references, both numeric and by name, in patterns that made use of
697        duplicate group numbers, could behave incorrectly or give incorrect errors,
698        because when scanning forward to find the reference group, PCRE was not
699        taking into account the duplicate group numbers. A pattern such as
700        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
702    26. Changed a few more instances of "const unsigned char *" to USPTR, making
703        the feature of a custom pointer more persuasive (as requested by a user).
705    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
706        pcretest.c, inside #ifndefs, because it seems they are sometimes already
707        pre-defined.
709    28. Added support for (*UTF8) at the start of a pattern.
711    29. Arrange for flags added by the "release type" setting in CMake to be shown
712        in the configuration summary.
715    Version 7.8 05-Sep-08
716    ---------------------
718    1.  Replaced UCP searching code with optimized version as implemented for Ad
719        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
720        stage table and inline lookup instead of a function, giving speed ups of 2
721        to 5 times on some simple patterns that I tested. Permission was given to
722        distribute the MultiStage2.py script that generates the tables (it's not in
723        the tarball, but is in the Subversion repository).
725    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
726        scripts.
728    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
729        a group with a zero qualifier. The result of the study could be incorrect,
730        or the function might crash, depending on the pattern.
732    4.  Caseless matching was not working for non-ASCII characters in back
733        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
734        It now works when Unicode Property Support is available.
736    5.  In pcretest, an escape such as \x{de} in the data was always generating
737        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
738        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
739        truncation.
741    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
743    7.  Added two (int) casts to pcregrep when printing the difference of two
744        pointers, in case they are 64-bit values.
746    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
747        test 2 if it fails.
749    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
750        and a #define of that name to empty if it is not externally set. This is to
751        allow users of MSVC to set it if necessary.
753    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
754        the convenience functions in the pcre_get.c source file.
756    11. An option change at the start of a pattern that had top-level alternatives
757        could cause overwriting and/or a crash. This command provoked a crash in
758        some environments:
760          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
762        This potential security problem was recorded as CVE-2008-2371.
764    12. For a pattern where the match had to start at the beginning or immediately
765        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
766        pcre_dfa_exec() could read past the end of the passed subject if there was
767        no match. To help with detecting such bugs (e.g. with valgrind), I modified
768        pcretest so that it places the subject at the end of its malloc-ed buffer.
770    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
771        exec() might read past the end of the data buffer in UTF-8 mode.
773    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
774        the data contained the byte 0x85 as part of a UTF-8 character within its
775        first line. This applied both to normal and DFA matching.
777    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
778        /^[^d]*?$/8 failed to match "abc".
780    16. Added a missing copyright notice to pcrecpp_internal.h.
782    17. Make it more clear in the documentation that values returned from
783        pcre_exec() in ovector are byte offsets, not character counts.
785    18. Tidied a few places to stop certain compilers from issuing warnings.
787    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
788        supplied by Stefan Weber. I made a further small update for 7.8 because
789        there is a change of source arrangements: the pcre_searchfuncs.c module is
790        replaced by pcre_ucd.c.
793    Version 7.7 07-May-08
794    ---------------------
796    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
797        a string to a long long, pretend we don't even have a long long." This is
798        done by checking for the strtoq, strtoll, and _strtoi64 functions.
800    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
801        pre-7.6 versions, which defined a global no_arg variable instead of putting
802        it in the RE class. (See also #8 below.)
804    3.  Remove a line of dead code, identified by coverity and reported by Nuno
805        Lopes.
807    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
809        (1) The include/exclude patterns were being applied to the whole pathnames
810            of files, instead of just to the final components.
812        (2) If there was more than one level of directory, the subdirectories were
813            skipped unless they satisfied the include/exclude conditions. This is
814            inconsistent with GNU grep (and could even be seen as contrary to the
815            pcregrep specification - which I improved to make it absolutely clear).
816            The action now is always to scan all levels of directory, and just
817            apply the include/exclude patterns to regular files.
819    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
820        --exclude_dir in the tests to avoid scanning .svn directories.
822    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
823        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
824        doesn't support NULs in patterns.
826    7.  Added some missing "const"s to declarations of static tables in
827        pcre_compile.c and pcre_dfa_exec.c.
829    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
830        caused by fix #2  above. (Subsequently also a second patch to fix the
831        first patch. And a third patch - this was a messy problem.)
833    9.  Applied Craig's patch to remove the use of push_back().
835    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
836        matching function regexec().
838    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
839        which, however, unlike Perl's \g{...}, are subroutine calls, not back
840        references. PCRE supports relative numbers with this syntax (I don't think
841        Oniguruma does).
843    12. Previously, a group with a zero repeat such as (...){0} was completely
844        omitted from the compiled regex. However, this means that if the group
845        was called as a subroutine from elsewhere in the pattern, things went wrong
846        (an internal error was given). Such groups are now left in the compiled
847        pattern, with a new opcode that causes them to be skipped at execution
848        time.
850    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
851        to the way PCRE behaves:
853        (a) A lone ] character is dis-allowed (Perl treats it as data).
855        (b) A back reference to an unmatched subpattern matches an empty string
856            (Perl fails the current match path).
858        (c) A data ] in a character class must be notated as \] because if the
859            first data character in a class is ], it defines an empty class. (In
860            Perl it is not possible to have an empty class.) The empty class []
861            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
862            The negative empty class [^] matches any one character, independently
863            of the DOTALL setting.
865    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
866        non-existent subpattern following a character class starting with ']' and
867        containing () gave an internal compiling error instead of "reference to
868        non-existent subpattern". Fortunately, when the pattern did exist, the
869        compiled code was correct. (When scanning forwards to check for the
870        existencd of the subpattern, it was treating the data ']' as terminating
871        the class, so got the count wrong. When actually compiling, the reference
872        was subsequently set up correctly.)
874    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
875        it was being rejected as not supported by pcre_dfa_exec(), even though
876        other assertions are supported. I have made pcre_dfa_exec() support
877        (*FAIL).
879    16. The implementation of 13c above involved the invention of a new opcode,
880        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
881        cannot be changed at match time, I realized I could make a small
882        improvement to matching performance by compiling OP_ALLANY instead of
883        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
884        on the OP_ANY path.
886    17. Compiling pcretest on Windows with readline support failed without the
887        following two fixes: (1) Make the unistd.h include conditional on
888        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
890    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
891        ncurses library to be included for pcretest when ReadLine support is
892        requested, but also to allow for it to be overridden. This patch came from
893        Daniel Bergström.
895    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
896        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
897        any errors with the current Unicode tables. Thanks to Peter Kankowski for
898        spotting this.
901    Version 7.6 28-Jan-08
902    ---------------------
904    1.  A character class containing a very large number of characters with
905        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
906        overflow.
908    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
909        HAVE_LONG_LONG is not defined.
911    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
912        bring them up to date and include new features. This patch includes:
914        - Fixed PH's badly added libz and libbz2 support.
915        - Fixed a problem with static linking.
916        - Added pcredemo. [But later removed - see 7 below.]
917        - Fixed dftables problem and added an option.
918        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
919            HAVE_LONG_LONG.
920        - Added readline support for pcretest.
921        - Added an listing of the option settings after cmake has run.
923    4.  A user submitted a patch to Makefile that makes it easy to create
924        "pcre.dll" under mingw when using Configure/Make. I added stuff to
925        Makefile.am that cause it to include this special target, without
926        affecting anything else. Note that the same mingw target plus all
927        the other distribution libraries and programs are now supported
928        when configuring with CMake (see 6 below) instead of with
929        Configure/Make.
931    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
932        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
933        exported in the Windows port". It has not yet been confirmed that the patch
934        solves the problem, but it does no harm.
936    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
937        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
938        with CMake, and also correct the comment about stack recursion.
940    7.  Remove the automatic building of pcredemo from the ./configure system and
941        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
942        of a program that users should build themselves after PCRE is installed, so
943        building it automatically is not really right. What is more, it gave
944        trouble in some build environments.
946    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
949    Version 7.5 10-Jan-08
950    ---------------------
952    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
953        values in parens when parsing an RE using the C++ wrapper."
955    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
956        Characters greater than 255 were excluded from the class instead of being
957        included.
959    3.  The same bug as (2) above applied to negated POSIX classes such as
960        [:^space:].
962    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
963        defined or documented. It seems to have been a typo for PCRE_STATIC, so
964        I have changed it.
966    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
967        first named subpattern) and a construct such as (?&a) would reference the
968        first named subpattern whose name started with "a" (in other words, the
969        length check was missing). Both these problems are fixed. "Subpattern name
970        expected" is now given for (?&) (a zero-length name), and this patch also
971        makes it give the same error for \k'' (previously it complained that that
972        was a reference to a non-existent subpattern).
974    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
975        this is right because (?- can be followed by option settings as well as by
976        digits. I have, however, made the messages clearer.
978    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
979        than the number used in the conditional) now cause a compile-time error.
980        This is actually not compatible with Perl, which accepts such patterns, but
981        treats the conditional as always being FALSE (as PCRE used to), but it
982        seems to me that giving a diagnostic is better.
984    8.  Change "alphameric" to the more common word "alphanumeric" in comments
985        and messages.
987    9.  Fix two occurrences of "backslash" in comments that should have been
988        "backspace".
990    10. Remove two redundant lines of code that can never be obeyed (their function
991        was moved elsewhere).
993    11. The program that makes PCRE's Unicode character property table had a bug
994        which caused it to generate incorrect table entries for sequences of
995        characters that have the same character type, but are in different scripts.
996        It amalgamated them into a single range, with the script of the first of
997        them. In other words, some characters were in the wrong script. There were
998        thirteen such cases, affecting characters in the following ranges:
1000          U+002b0 - U+002c1
1001          U+0060c - U+0060d
1002          U+0061e - U+00612
1003          U+0064b - U+0065e
1004          U+0074d - U+0076d
1005          U+01800 - U+01805
1006          U+01d00 - U+01d77
1007          U+01d9b - U+01dbf
1008          U+0200b - U+0200f
1009          U+030fc - U+030fe
1010          U+03260 - U+0327f
1011          U+0fb46 - U+0fbb1
1012          U+10450 - U+1049d
1014    12. The -o option (show only the matching part of a line) for pcregrep was not
1015        compatible with GNU grep in that, if there was more than one match in a
1016        line, it showed only the first of them. It now behaves in the same way as
1017        GNU grep.
1019    13. If the -o and -v options were combined for pcregrep, it printed a blank
1020        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1021        does the same. The return code can be used to tell if there were any
1022        non-matching lines.
1024    14. Added --file-offsets and --line-offsets to pcregrep.
1026    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1027        infinitely looping recursion. The bug was that positive lookaheads were not
1028        being skipped when checking for a possible empty match (negative lookaheads
1029        and both kinds of lookbehind were skipped).
1031    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1032        inclusion of <windows.h> to before rather than after the definition of
1033        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1035    17. Specifying a possessive quantifier with a specific limit for a Unicode
1036        character property caused pcre_compile() to compile bad code, which led at
1037        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1038        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1039        caused the error; without that there was no problem.
1041    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1043    19. Added --enable-pcretest-libreadline.
1045    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1046        RE::GlobalReplace(). As a result, the number of replacements returned was
1047        double what it should be. I removed one of the increments, but Craig sent a
1048        later patch that removed the other one (the right fix) and added unit tests
1049        that check the return values (which was not done before).
1051    21. Several CMake things:
1053        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1054            the names libpcre and libpcreposix, not just pcre and pcreposix.
1056        (2) The above change means that pcretest and pcregrep are now correctly
1057            linked with the newly-built libraries, not previously installed ones.
1061    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1062        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1063        UTF-8 newline character). The key issue is that the pattern starts .*;
1064        this means that the match must be either at the beginning, or after a
1065        newline. The bug was in the code for advancing after a failed match and
1066        checking that the new position followed a newline. It was not taking
1067        account of UTF-8 characters correctly.
1069    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1070        character classes. PCRE was not treating the sequence [:...:] as a
1071        character class unless the ... were all letters. Perl, however, seems to
1072        allow any characters between [: and :], though of course it rejects as
1073        unknown any "names" that contain non-letters, because all the known class
1074        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1075        for example, whereas PCRE did not - it did not recognize a POSIX character
1076        class. This seemed a bit dangerous, so the code has been changed to be
1077        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1078        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1079        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1080        Perl does, and where it didn't before.
1082    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1083        Windows environments %n is disabled by default.
1086    Version 7.4 21-Sep-07
1087    ---------------------
1089    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1090        means that a class such as [\s] counted as "explicit reference to CR or
1091        LF". That isn't really right - the whole point of the change was to try to
1092        help when there was an actual mention of one of the two characters. So now
1093        the change happens only if \r or \n (or a literal CR or LF) character is
1094        encountered.
1096    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1097        of both had grown to the point where there were only 3 bits left.
1098        Fortunately, there was spare space in the data structure, and so I have
1099        moved the internal flags into a new 16-bit field to free up more option
1100        bits.
1102    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1103        but did not set the internal JCHANGED flag - either of these is enough to
1104        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1105        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1106        start sets both bits.
1108    4.  Added options (at build time, compile time, exec time) to change \R from
1109        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1111    5.  doc/pcresyntax.html was missing from the distribution.
1113    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1114        compatibility, even though it is no longer used.
1116    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1117        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1118        windows.h file is present (where different names are used). [This was
1119        reversed later after testing - see 16 below.]
1121    8.  Changed all #include <config.h> to #include "config.h". There were also
1122        some further <pcre.h> cases that I changed to "pcre.h".
1124    9.  When pcregrep was used with the --colour option, it missed the line ending
1125        sequence off the lines that it output.
1127    10. It was pointed out to me that arrays of string pointers cause lots of
1128        relocations when a shared library is dynamically loaded. A technique of
1129        using a single long string with a table of offsets can drastically reduce
1130        these. I have refactored PCRE in four places to do this. The result is
1131        dramatic:
1133          Originally:                          290
1134          After changing UCP table:            187
1135          After changing error message table:   43
1136          After changing table of "verbs"       36
1137          After changing table of Posix names   22
1139        Thanks to the folks working on Gregex for glib for this insight.
1141    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1142        unicode-properties was also set.
1144    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1146    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1147        checked only for CRLF.
1149    14. Added casts to pcretest.c to avoid compiler warnings.
1151    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1153    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1154        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1155        entirely. This removes changes made in 7 above.
1157    17. The CMake files have been updated, and there is now more information about
1158        building with CMake in the NON-UNIX-USE document.
1161    Version 7.3 28-Aug-07
1162    ---------------------
1164     1. In the rejigging of the build system that eventually resulted in 7.1, the
1165        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1166        brackets there is not right, since it causes compilers to look for an
1167        installed pcre.h, not the version that is in the source that is being
1168        compiled (which of course may be different). I have changed it back to:
1170          #include "pcre.h"
1172        I have a vague recollection that the change was concerned with compiling in
1173        different directories, but in the new build system, that is taken care of
1174        by the VPATH setting the Makefile.
1176     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1177        when the subject happened to end in the byte 0x85 (e.g. if the last
1178        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1179        characters but of course it shouldn't be taken as a newline when it is part
1180        of another character. The bug was that, for an unlimited repeat of . in
1181        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1182        characters when looking for a newline.
1184     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1186     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1187        in debug output.
1189     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1190        long printing in the pcrecpp unittest when running under MinGW.
1192     6. ESC_K was left out of the EBCDIC table.
1194     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1195        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1196        limit also applies to "virtual nesting" when a pattern is recursive, and in
1197        this case 1000 isn't so big. I have been able to remove this limit at the
1198        expense of backing off one optimization in certain circumstances. Normally,
1199        when pcre_exec() would call its internal match() function recursively and
1200        immediately return the result unconditionally, it uses a "tail recursion"
1201        feature to save stack. However, when a subpattern that can match an empty
1202        string has an unlimited repetition quantifier, it no longer makes this
1203        optimization. That gives it a stack frame in which to save the data for
1204        checking that an empty string has been matched. Previously this was taken
1205        from the 1000-entry workspace that had been reserved. So now there is no
1206        explicit limit, but more stack is used.
1208     8. Applied Daniel's patches to solve problems with the import/export magic
1209        syntax that is required for Windows, and which was going wrong for the
1210        pcreposix and pcrecpp parts of the library. These were overlooked when this
1211        problem was solved for the main library.
1213     9. There were some crude static tests to avoid integer overflow when computing
1214        the size of patterns that contain repeated groups with explicit upper
1215        limits. As the maximum quantifier is 65535, the maximum group length was
1216        set at 30,000 so that the product of these two numbers did not overflow a
1217        32-bit integer. However, it turns out that people want to use groups that
1218        are longer than 30,000 bytes (though not repeat them that many times).
1219        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1220        made it possible to implement the integer overflow checks in a much more
1221        dynamic way, which I have now done. The artificial limitation on group
1222        length has been removed - we now have only the limit on the total length of
1223        the compiled pattern, which depends on the LINK_SIZE setting.
1225    10. Fixed a bug in the documentation for get/copy named substring when
1226        duplicate names are permitted. If none of the named substrings are set, the
1227        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1228        empty string.
1230    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1231        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1232        because the ] is interpreted as the first data character and the
1233        terminating ] is not found. PCRE has been made compatible with Perl in this
1234        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1235        cause memory overwriting.
1237    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1238        string has been matched (to stop an infinite loop). It was not recognizing
1239        a conditional subpattern that could match an empty string if that
1240        subpattern was within another subpattern. For example, it looped when
1241        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1242        condition was not nested. This bug has been fixed.
1244    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1245        past the start of the subject in the presence of bytes with the top bit
1246        set, for example "\x8aBCD".
1248    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1249        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1251    14. Optimized (?!) to (*FAIL).
1253    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1254        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1255        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1256        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1257        does: it's just the validity check that is more restrictive.
1259    16. Inserted checks for integer overflows during escape sequence (backslash)
1260        processing, and also fixed erroneous offset values for syntax errors during
1261        backslash processing.
1263    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1264        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1266    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1267        caused an overrun.
1269    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1270        something other than just ASCII characters) inside a group that had an
1271        unlimited repeat caused a loop at compile time (while checking to see
1272        whether the group could match an empty string).
1274    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1275        [\P{Any}] did so. (Error in the code for printing property names.)
1277    21. An orphan \E inside a character class could cause a crash.
1279    22. A repeated capturing bracket such as (A)? could cause a wild memory
1280        reference during compilation.
1282    23. There are several functions in pcre_compile() that scan along a compiled
1283        expression for various reasons (e.g. to see if it's fixed length for look
1284        behind). There were bugs in these functions when a repeated \p or \P was
1285        present in the pattern. These operators have additional parameters compared
1286        with \d, etc, and these were not being taken into account when moving along
1287        the compiled data. Specifically:
1289        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1290            length.
1292        (b) An item such as \pL+ within a repeated group could cause crashes or
1293            loops.
1295        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1296            "reference to non-existent subpattern" error.
1298        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1300    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1301        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1303    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1305    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1306        character were causing crashes (broken optimization).
1308    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1309        \p or \P) caused a compile-time loop.
1311    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1312        break. For example, the unstudied pattern [\r\n]A does not match the string
1313        "\r\nA" because change 7.0/46 below moves the current point on by two
1314        characters after failing to match at the start. However, the pattern \nA
1315        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1316        the same is true. There doesn't seem any very clean way out of this, but
1317        what I have chosen to do makes the common cases work: PCRE now takes note
1318        of whether there can be an explicit match for \r or \n anywhere in the
1319        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1320        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1321        pattern has explicit CR or LF references.
1323    29. Added (*CR) etc for changing newline setting at start of pattern.
1326    Version 7.2 19-Jun-07
1327    ---------------------
1329     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1330        which is apparently normally available under Windows.
1332     2. Re-jig the pcregrep tests with different newline settings in an attempt
1333        to make them independent of the local environment's newline setting.
1335     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1337     4. Some of the "internals" tests were previously cut out when the link size
1338        was not 2, because the output contained actual offsets. The recent new
1339        "Z" feature of pcretest means that these can be cut out, making the tests
1340        usable with all link sizes.
1342     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1343        stack recursion. This gives a massive performance boost under BSD, but just
1344        a small improvement under Linux. However, it saves one field in the frame
1345        in all cases.
1347     6. Added more features from the forthcoming Perl 5.10:
1349        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1350            recursion call. It refers to the nth most recently opened parentheses.
1352        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1353            to be opened parentheses.
1355        (c) Conditions that refer to capturing parentheses can be specified
1356            relatively, for example, (?(-2)... or (?(+3)...
1358        (d) \K resets the start of the current match so that everything before
1359            is not part of it.
1361        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1363        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1364            reference syntax.
1366        (g) (?| introduces a group in which the numbering of parentheses in each
1367            alternative starts with the same number.
1369        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1371     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1374     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1375        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1376        for detecting groups that can match an empty string.
1378     9. A pattern with a very large number of alternatives (more than several
1379        hundred) was running out of internal workspace during the pre-compile
1380        phase, where pcre_compile() figures out how much memory will be needed. A
1381        bit of new cunning has reduced the workspace needed for groups with
1382        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1383        workspace instead of running out of the 4096 that are available.
1385    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1387    11. Applied patch from Google to remove an optimization that didn't quite work.
1388        The report of the bug said:
1390          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1391          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1392          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1394    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1395        it matched the wrong number of bytes.
1398    Version 7.1 24-Apr-07
1399  ---------------------  ---------------------
1401   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1402      that is more "standard", making use of automake and other autotools. There      that is more "standard", making use of automake and other Autotools. There
1403      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
1404      on this.      on this.
# Line 21  Version 7.1 05-Mar-07 Line 1415  Version 7.1 05-Mar-07
1415      people do their own conversions for various reasons). The problems      people do their own conversions for various reasons). The problems
1416      concerned the use of low-level troff macros .br and .in. I have therefore      concerned the use of low-level troff macros .br and .in. I have therefore
1417      removed all such uses from the man pages (some were redundant, some could      removed all such uses from the man pages (some were redundant, some could
1418      be replaced by .nf/.fi pairs). The maintain/132html script that I use to      be replaced by .nf/.fi pairs). The 132html script that I use to generate
1419      generate HTML has been updated to handle .nf/.fi and to complain if it      HTML has been updated to handle .nf/.fi and to complain if it encounters
1420      encounters .br or .in.      .br or .in.
1422   4. Updated comments in configure.ac that get placed in config.h.in and also   4. Updated comments in configure.ac that get placed in config.h.in and also
1423      arranged for config.h to be included in the distribution, with the name      arranged for config.h to be included in the distribution, with the name
1424      config.h.generic, for the benefit of those who have to compile without      config.h.generic, for the benefit of those who have to compile without
1425      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1427   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1428      Weber: (1) pcre_internal.h was missing some function renames; (2) updated      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1429      makevp.bat for the current PCRE, using the additional files !compile.txt,      makevp.bat for the current PCRE, using the additional files
1430      !linklib.txt, and pcregexp.pas.      makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1432   6. A Windows user reported a minor discrepancy with test 2, which turned out   6. A Windows user reported a minor discrepancy with test 2, which turned out
1433      to be caused by a trailing space on an input line that had got lost in his      to be caused by a trailing space on an input line that had got lost in his
# Line 60  Version 7.1 05-Mar-07 Line 1454  Version 7.1 05-Mar-07
1454      called when UTF-8 support is disabled. Otherwise there are problems with a      called when UTF-8 support is disabled. Otherwise there are problems with a
1455      shared library.      shared library.
1457  10. The emulated memmove() function in pcre_internal.h (provided for those  10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1458      environments that have neither memmove() nor bcopy()) was defining its  
1459      arguments as char * instead of void *.      (a) It was defining its arguments as char * instead of void *.
1461        (b) It was assuming that all moves were upwards in memory; this was true
1462            a long time ago when I wrote it, but is no longer the case.
1464        The emulated memove() is provided for those environments that have neither
1465        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1466        is clearly not the case, as these two bugs were recently reported.
1468  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1469      and Detrail to create the HTML documentation, the .txt form of the man      and Detrail to create the HTML documentation, the .txt form of the man
1470      pages, and it removes trailing spaces from listed files. It also creates      pages, and it removes trailing spaces from listed files. It also creates
1471      pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter      pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1472      case, it wraps all the #defines with #ifndefs. This script should be run      case, it wraps all the #defines with #ifndefs. This script should be run
1473      before "make dist".      before "make dist".
1475    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1476        with Unicode property support.
1478        (a) For a maximizing quantifier, if the two different cases of the
1479            character were of different lengths in their UTF-8 codings (there are
1480            some cases like this - I found 11), and the matching function had to
1481            back up over a mixture of the two cases, it incorrectly assumed they
1482            were both the same length.
1484        (b) When PCRE was configured to use the heap rather than the stack for
1485            recursion during matching, it was not correctly preserving the data for
1486            the other case of a UTF-8 character when checking ahead for a match
1487            while processing a minimizing repeat. If the check also involved
1488            matching a wide character, but failed, corruption could cause an
1489            erroneous result when trying to check for a repeat of the original
1490            character.
1492    13. Some tidying changes to the testing mechanism:
1494        (a) The RunTest script now detects the internal link size and whether there
1495            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1496            values substituted by "configure". (The RunGrepTest script already did
1497            this for UTF-8.) The configure.ac script no longer substitutes the
1498            relevant variables.
1500        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1501            with length and offset values. This means that the output is different
1502            for different internal link sizes. Test 2 is skipped for link sizes
1503            other than 2 because of this, bypassing the problem. Unfortunately,
1504            there was also a test in test 3 (the locale tests) that used /B and
1505            failed for link sizes other than 2. Rather than cut the whole test out,
1506            I have added a new /Z option to pcretest that replaces the length and
1507            offset values with spaces. This is now used to make test 3 independent
1508            of link size. (Test 2 will be tidied up later.)
1510    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1511        segmentation fault instead of returning the appropriate error message.
1513    15. In multiline mode when the newline sequence was set to "any", the pattern
1514        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1515        This doesn't seem right; it now treats the CRLF combination as the line
1516        ending, and so does not match in that case. It's only a pattern such as ^$
1517        that would hit this one: something like ^ABC$ would have failed after \r
1518        and then tried again after \r\n.
1520    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1521        in an attempt to make files that differ only in their line terminators
1522        compare equal. This works on Linux.
1524    17. Under certain error circumstances pcregrep might try to free random memory
1525        as it exited. This is now fixed, thanks to valgrind.
1527    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1528        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1529        was because its rules for how to advance for /g after matching an empty
1530        string at the end of a line did not allow for this case. They now check for
1531        it specially.
1533    20. pcretest is supposed to handle patterns and data of any length, by
1534        extending its buffers when necessary. It was getting this wrong when the
1535        buffer for a data line had to be extended.
1537    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1538        CRLF as a newline sequence.
1540    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1541        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1542        I have nevertheless tidied it up.
1544    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1546    24. Added a man page for pcre-config.
1549  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1550  ---------------------  ---------------------

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