/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 108 by ph10, Wed Mar 7 11:11:23 2007 UTC revision 530 by ph10, Tue Jun 1 13:42:06 2010 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  Version 8.10 03 May-2010
5    ------------------------
6    
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
9    
10    2.  (*ACCEPT) was not working when inside an atomic group.
11    
12    3.  Inside a character class, \B is treated as a literal by default, but
13        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14        causes the error). The code is unchanged, but I tidied the documentation.
15    
16    4.  Inside a character class, PCRE always treated \R and \X as literals,
17        whereas Perl faults them if its -w option is set. I have changed PCRE so
18        that it faults them when PCRE_EXTRA is set.
19    
20    5.  Added support for \N, which always matches any character other than
21        newline. (It is the same as "." when PCRE_DOTALL is not set.)
22    
23    6.  When compiling pcregrep with newer versions of gcc which may have
24        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25        declared with attribute warn_unused_result" were given. Just casting the
26        result to (void) does not stop the warnings; a more elaborate fudge is
27        needed. I've used a macro to implement this.
28    
29    7.  Minor change to pcretest.c to avoid a compiler warning.
30    
31    8.  Added four artifical Unicode properties to help with an option to make
32        \s etc use properties (see next item). The new properties are: Xan
33        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34    
35    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36        use Unicode properties. (*UCP) at the start of a pattern can be used to set
37        this option. Modified pcretest to add /W to test this facility. Added
38        REG_UCP to make it available via the POSIX interface.
39    
40    10. Added --line-buffered to pcregrep.
41    
42    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43        studied, and the match started with a letter with a code point greater than
44        127 whose first byte was different to the first byte of the other case of
45        the letter, the other case of this starting letter was not recognized.
46    
47    12. pcreposix.c included pcre.h before including pcre_internal.h. This caused a
48        conflict in the definition of PCRE_EXP_DECL. I have removed the include of
49        pcre.h as pcre_internal.h includes pcre.h itself. (This may be a bit of
50        historical tidying that never got done.)
51    
52    13. If a pattern that was studied started with a repeated Unicode property
53        test, for example, \p{Nd}+, there was the theoretical possibility of
54        setting up an incorrect bitmap of starting bytes, but fortunately it could
55        not have actually happened in practice until change 8 above was made (it
56        added property types that matched character-matching opcodes).
57    
58    14. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
59        possible starting bytes for non-anchored patterns.
60    
61    15. The "auto-possessify" feature of pcre_compile() now recognizes \R.
62    
63    16. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
64        input, it could crash or give wrong results if characters with values
65        greater than 0xc0 were present in the subject string. (Detail: it assumed
66        UTF-8 input when processing these items.)
67    
68    17. Added a lot of (int) casts to avoid compiler warnings in systems where
69        size_t is 64-bit.
70    
71    
72    
73    Version 8.02 19-Mar-2010
74    ------------------------
75    
76    1.  The Unicode data tables have been updated to Unicode 5.2.0.
77    
78    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
79        configured.
80    
81    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
82        original author of that file, following a query about its status.
83    
84    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
85        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
86    
87    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
88        quantifier applied to a forward-referencing subroutine call, could compile
89        incorrect code or give the error "internal error: previously-checked
90        referenced subpattern not found".
91    
92    6.  Both MS Visual Studio and Symbian OS have problems with initializing
93        variables to point to external functions. For these systems, therefore,
94        pcre_malloc etc. are now initialized to local functions that call the
95        relevant global functions.
96    
97    7.  There were two entries missing in the vectors called coptable and poptable
98        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
99        I've fixed the data, and added a kludgy way of testing at compile time that
100        the lengths are correct (equal to the number of opcodes).
101    
102    8.  Following on from 7, I added a similar kludge to check the length of the
103        eint vector in pcreposix.c.
104    
105    9.  Error texts for pcre_compile() are held as one long string to avoid too
106        much relocation at load time. To find a text, the string is searched,
107        counting zeros. There was no check for running off the end of the string,
108        which could happen if a new error number was added without updating the
109        string.
110    
111    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
112    
113    11. \K was not working if it appeared in an atomic group or in a group that
114        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
115        \K is "not well defined" if used in an assertion. PCRE now accepts it if
116        the assertion is positive, but not if it is negative.
117    
118    12. Change 11 fortuitously reduced the size of the stack frame used in the
119        "match()" function of pcre_exec.c by one pointer. Forthcoming
120        implementation of support for (*MARK) will need an extra pointer on the
121        stack; I have reserved it now, so that the stack frame size does not
122        decrease.
123    
124    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
125        item in branch that calls a recursion is a subroutine call - as in the
126        second branch in the above example - was incorrectly given the compile-
127        time error "recursive call could loop indefinitely" because pcre_compile()
128        was not correctly checking the subroutine for matching a non-empty string.
129    
130    14. The checks for overrunning compiling workspace could trigger after an
131        overrun had occurred. This is a "should never occur" error, but it can be
132        triggered by pathological patterns such as hundreds of nested parentheses.
133        The checks now trigger 100 bytes before the end of the workspace.
134    
135    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
136    
137    
138    Version 8.01 19-Jan-2010
139    ------------------------
140    
141    1.  If a pattern contained a conditional subpattern with only one branch (in
142        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
143        computed the wrong minimum data length (which is of course zero for such
144        subpatterns). This could cause incorrect "no match" results.
145    
146    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
147        the pattern is reset in the first branch, pcre_compile() failed with
148        "internal error: code overflow at offset...". This happened only when
149        the reset was to the original external option setting. (An optimization
150        abstracts leading options settings into an external setting, which was the
151        cause of this.)
152    
153    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
154        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
155        assertion pattern did not match (meaning that the assertion was true), it
156        was incorrectly treated as false if the SKIP had been reached during the
157        matching. This also applied to assertions used as conditions.
158    
159    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
160        assertion subpattern, including such a pattern used as a condition,
161        unpredictable results occurred, instead of the error return
162        PCRE_ERROR_DFA_UITEM.
163    
164    5.  The C++ GlobalReplace function was not working like Perl for the special
165        situation when an empty string is matched. It now does the fancy magic
166        stuff that is necessary.
167    
168    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
169        removed. (These were left over from very, very early versions of PCRE.)
170    
171    7.  Some cosmetic changes to the code to make life easier when compiling it
172        as part of something else:
173    
174        (a) Change DEBUG to PCRE_DEBUG.
175    
176        (b) In pcre_compile(), rename the member of the "branch_chain" structure
177            called "current" as "current_branch", to prevent a collision with the
178            Linux macro when compiled as a kernel module.
179    
180        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
181            prevent a collision with the Linux macro when compiled as a kernel
182            module.
183    
184    8.  In pcre_compile() there are some checks for integer overflows that used to
185        cast potentially large values to (double). This has been changed to that
186        when building, a check for int64_t is made, and if it is found, it is used
187        instead, thus avoiding the use of floating point arithmetic. (There is no
188        other use of FP in PCRE.) If int64_t is not found, the fallback is to
189        double.
190    
191    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
192        2005 (difference between two addresses compared to an unsigned value).
193    
194    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
195        custom one, because of the following reported problem in Windows:
196    
197          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
198              under Win32.
199          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
200              therefore missing the function definition.
201          - The compiler thus generates a "C" signature for the test function.
202          - The linker fails to find the "C" function.
203          - PCRE fails to configure if asked to do so against libbz2.
204    
205    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
206        messages were output:
207    
208          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
209          rerunning libtoolize, to keep the correct libtool macros in-tree.
210          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
211    
212        I have done both of these things.
213    
214    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
215        most of the time, it *can* run out if it is given a pattern that contains a
216        runaway infinite recursion. I updated the discussion in the pcrestack man
217        page.
218    
219    13. Now that we have gone to the x.xx style of version numbers, the minor
220        version may start with zero. Using 08 or 09 is a bad idea because users
221        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
222        interpreted as invalid octal numbers. I've updated the previous comment in
223        configure.ac, and also added a check that gives an error if 08 or 09 are
224        used.
225    
226    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
227        causing partial matching to fail when the end of the subject matched \W
228        in a UTF-8 pattern where \W was quantified with a minimum of 3.
229    
230    15. There were some discrepancies between the declarations in pcre_internal.h
231        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
232        their definitions. The declarations used "const uschar *" and the
233        definitions used USPTR. Even though USPTR is normally defined as "const
234        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
235        reported that: "This difference in casting confuses some C++ compilers, for
236        example, SunCC recognizes above declarations as different functions and
237        generates broken code for hbpcre." I have changed the declarations to use
238        USPTR.
239    
240    16. GNU libtool is named differently on some systems. The autogen.sh script now
241        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
242        (FreeBSD).
243    
244    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
245        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
246        comment: "Figure out how to create a longlong from a string: strtoll and
247        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
248        instance, but it only takes 2 args instead of 3!"
249    
250    18. A subtle bug concerned with back references has been fixed by a change of
251        specification, with a corresponding code fix. A pattern such as
252        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
253        refers, was giving matches when it shouldn't. For example, xa=xaaa would
254        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
255        same bug. Such groups have to be quantified to be useful, or contained
256        inside another quantified group. (If there's no repetition, the reference
257        can never match.) The problem arises because, having left the group and
258        moved on to the rest of the pattern, a later failure that backtracks into
259        the group uses the captured value from the final iteration of the group
260        rather than the correct earlier one. I have fixed this in PCRE by forcing
261        any group that contains a reference to itself to be an atomic group; that
262        is, there cannot be any backtracking into it once it has completed. This is
263        similar to recursive and subroutine calls.
264    
265    
266    Version 8.00 19-Oct-09
267    ----------------------
268    
269    1.  The table for translating pcre_compile() error codes into POSIX error codes
270        was out-of-date, and there was no check on the pcre_compile() error code
271        being within the table. This could lead to an OK return being given in
272        error.
273    
274    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
275        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
276        in a Windows environment.
277    
278    3.  The pcregrep --count option prints the count for each file even when it is
279        zero, as does GNU grep. However, pcregrep was also printing all files when
280        --files-with-matches was added. Now, when both options are given, it prints
281        counts only for those files that have at least one match. (GNU grep just
282        prints the file name in this circumstance, but including the count seems
283        more useful - otherwise, why use --count?) Also ensured that the
284        combination -clh just lists non-zero counts, with no names.
285    
286    4.  The long form of the pcregrep -F option was incorrectly implemented as
287        --fixed_strings instead of --fixed-strings. This is an incompatible change,
288        but it seems right to fix it, and I didn't think it was worth preserving
289        the old behaviour.
290    
291    5.  The command line items --regex=pattern and --regexp=pattern were not
292        recognized by pcregrep, which required --regex pattern or --regexp pattern
293        (with a space rather than an '='). The man page documented the '=' forms,
294        which are compatible with GNU grep; these now work.
295    
296    6.  No libpcreposix.pc file was created for pkg-config; there was just
297        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
298    
299    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
300        when UCP support is not needed, by modifying the Python script that
301        generates it from Unicode data files. This should not matter if the module
302        is correctly used as a library, but I received one complaint about 50K of
303        unwanted data. My guess is that the person linked everything into his
304        program rather than using a library. Anyway, it does no harm.
305    
306    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
307        was a minimum greater than 1 for a wide character in a possessive
308        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
309        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
310        character. Chaos in the form of incorrect output or a compiling loop could
311        result.
312    
313    9.  The restrictions on what a pattern can contain when partial matching is
314        requested for pcre_exec() have been removed. All patterns can now be
315        partially matched by this function. In addition, if there are at least two
316        slots in the offset vector, the offset of the earliest inspected character
317        for the match and the offset of the end of the subject are set in them when
318        PCRE_ERROR_PARTIAL is returned.
319    
320    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
321        synonymous with PCRE_PARTIAL, for backwards compatibility, and
322        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
323        and may be more useful for multi-segment matching.
324    
325    11. Partial matching with pcre_exec() is now more intuitive. A partial match
326        used to be given if ever the end of the subject was reached; now it is
327        given only if matching could not proceed because another character was
328        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
329        string "Z", which now yields "no match" instead of "partial match". In the
330        case of pcre_dfa_exec(), "no match" is given if every matching path for the
331        final character ended with (*FAIL).
332    
333    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
334        if the pattern had a "must contain" character that was already found in the
335        earlier partial match, unless partial matching was again requested. For
336        example, with the pattern /dog.(body)?/, the "must contain" character is
337        "g". If the first part-match was for the string "dog", restarting with
338        "sbody" failed. This bug has been fixed.
339    
340    13. The string returned by pcre_dfa_exec() after a partial match has been
341        changed so that it starts at the first inspected character rather than the
342        first character of the match. This makes a difference only if the pattern
343        starts with a lookbehind assertion or \b or \B (\K is not supported by
344        pcre_dfa_exec()). It's an incompatible change, but it makes the two
345        matching functions compatible, and I think it's the right thing to do.
346    
347    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
348        so that the demonstration program is easily available in environments where
349        PCRE has not been installed from source.
350    
351    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
352        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
353        library.
354    
355    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
356        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
357        is not the first non-POSIX option to be added. Clearly some people find
358        these options useful.
359    
360    17. If a caller to the POSIX matching function regexec() passes a non-zero
361        value for nmatch with a NULL value for pmatch, the value of
362        nmatch is forced to zero.
363    
364    18. RunGrepTest did not have a test for the availability of the -u option of
365        the diff command, as RunTest does. It now checks in the same way as
366        RunTest, and also checks for the -b option.
367    
368    19. If an odd number of negated classes containing just a single character
369        interposed, within parentheses, between a forward reference to a named
370        subpattern and the definition of the subpattern, compilation crashed with
371        an internal error, complaining that it could not find the referenced
372        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
373        [The bug was that it was starting one character too far in when skipping
374        over the character class, thus treating the ] as data rather than
375        terminating the class. This meant it could skip too much.]
376    
377    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
378        /g option in pcretest when the pattern contains \K, which makes it possible
379        to have an empty string match not at the start, even when the pattern is
380        anchored. Updated pcretest and pcredemo to use this option.
381    
382    21. If the maximum number of capturing subpatterns in a recursion was greater
383        than the maximum at the outer level, the higher number was returned, but
384        with unset values at the outer level. The correct (outer level) value is
385        now given.
386    
387    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
388        PCRE did not set those parentheses (unlike Perl). I have now found a way to
389        make it do so. The string so far is captured, making this feature
390        compatible with Perl.
391    
392    23. The tests have been re-organized, adding tests 11 and 12, to make it
393        possible to check the Perl 5.10 features against Perl 5.10.
394    
395    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
396        pattern matches a fixed length string. PCRE did not allow this; now it
397        does. Neither allows recursion.
398    
399    25. I finally figured out how to implement a request to provide the minimum
400        length of subject string that was needed in order to match a given pattern.
401        (It was back references and recursion that I had previously got hung up
402        on.) This code has now been added to pcre_study(); it finds a lower bound
403        to the length of subject needed. It is not necessarily the greatest lower
404        bound, but using it to avoid searching strings that are too short does give
405        some useful speed-ups. The value is available to calling programs via
406        pcre_fullinfo().
407    
408    26. While implementing 25, I discovered to my embarrassment that pcretest had
409        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
410        study optimizations had never been tested with that matching function.
411        Oops. What is worse, even when it was passed study data, there was a bug in
412        pcre_dfa_exec() that meant it never actually used it. Double oops. There
413        were also very few tests of studied patterns with pcre_dfa_exec().
414    
415    27. If (?| is used to create subpatterns with duplicate numbers, they are now
416        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
417        on the other side of the coin, they are no longer allowed to have different
418        names, because these cannot be distinguished in PCRE, and this has caused
419        confusion. (This is a difference from Perl.)
420    
421    28. When duplicate subpattern names are present (necessarily with different
422        numbers, as required by 27 above), and a test is made by name in a
423        conditional pattern, either for a subpattern having been matched, or for
424        recursion in such a pattern, all the associated numbered subpatterns are
425        tested, and the overall condition is true if the condition is true for any
426        one of them. This is the way Perl works, and is also more like the way
427        testing by number works.
428    
429    
430    Version 7.9 11-Apr-09
431    ---------------------
432    
433    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
434        (pcretest), all targets were linked against these libraries. This included
435        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
436        libraries. This caused unwanted dependencies to be created. This problem
437        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
438        pcretest is linked with readline.
439    
440    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
441        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
442        moved outside it again, because FALSE and TRUE are already defined in AIX,
443        but BOOL is not.
444    
445    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
446        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
447    
448    4.  The pcregrep documentation said spaces were inserted as well as colons (or
449        hyphens) following file names and line numbers when outputting matching
450        lines. This is not true; no spaces are inserted. I have also clarified the
451        wording for the --colour (or --color) option.
452    
453    5.  In pcregrep, when --colour was used with -o, the list of matching strings
454        was not coloured; this is different to GNU grep, so I have changed it to be
455        the same.
456    
457    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
458        each matching line was coloured. Now it goes on to look for further matches
459        of any of the test patterns, which is the same behaviour as GNU grep.
460    
461    7.  A pattern that could match an empty string could cause pcregrep to loop; it
462        doesn't make sense to accept an empty string match in pcregrep, so I have
463        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
464        seems to be how GNU grep behaves.
465    
466    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
467        start or after a newline", because the conditional assertion was not being
468        correctly handled. The rule now is that both the assertion and what follows
469        in the first alternative must satisfy the test.
470    
471    9.  If auto-callout was enabled in a pattern with a conditional group whose
472        condition was an assertion, PCRE could crash during matching, both with
473        pcre_exec() and pcre_dfa_exec().
474    
475    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
476        used for matching.
477    
478    11. Unicode property support in character classes was not working for
479        characters (bytes) greater than 127 when not in UTF-8 mode.
480    
481    12. Added the -M command line option to pcretest.
482    
483    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
484    
485    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
486    
487    16. Added comments and documentation about mis-use of no_arg in the C++
488        wrapper.
489    
490    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
491        from Martin Jerabek that uses macro names for all relevant character and
492        string constants.
493    
494    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
495        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
496        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
497        these, but not everybody uses configure.
498    
499    19. A conditional group that had only one branch was not being correctly
500        recognized as an item that could match an empty string. This meant that an
501        enclosing group might also not be so recognized, causing infinite looping
502        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
503        with the subject "ab", where knowledge that the repeated group can match
504        nothing is needed in order to break the loop.
505    
506    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
507        exec(), but without supplying a callout function, matching went wrong.
508    
509    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
510        leak if the size of the offset vector was greater than 30. When the vector
511        is smaller, the saved offsets during recursion go onto a local stack
512        vector, but for larger vectors malloc() is used. It was failing to free
513        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
514        error, in fact).
515    
516    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
517        heapframe that is used only when UTF-8 support is enabled. This caused no
518        problem, but was untidy.
519    
520    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
521        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
522        included within another project.
523    
524    24. Steven Van Ingelgem's patches to add more options to the CMake support,
525        slightly modified by me:
526    
527          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
528              not building pcregrep.
529    
530          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
531              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
532    
533    25. Forward references, both numeric and by name, in patterns that made use of
534        duplicate group numbers, could behave incorrectly or give incorrect errors,
535        because when scanning forward to find the reference group, PCRE was not
536        taking into account the duplicate group numbers. A pattern such as
537        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
538    
539    26. Changed a few more instances of "const unsigned char *" to USPTR, making
540        the feature of a custom pointer more persuasive (as requested by a user).
541    
542    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
543        pcretest.c, inside #ifndefs, because it seems they are sometimes already
544        pre-defined.
545    
546    28. Added support for (*UTF8) at the start of a pattern.
547    
548    29. Arrange for flags added by the "release type" setting in CMake to be shown
549        in the configuration summary.
550    
551    
552    Version 7.8 05-Sep-08
553    ---------------------
554    
555    1.  Replaced UCP searching code with optimized version as implemented for Ad
556        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
557        stage table and inline lookup instead of a function, giving speed ups of 2
558        to 5 times on some simple patterns that I tested. Permission was given to
559        distribute the MultiStage2.py script that generates the tables (it's not in
560        the tarball, but is in the Subversion repository).
561    
562    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
563        scripts.
564    
565    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
566        a group with a zero qualifier. The result of the study could be incorrect,
567        or the function might crash, depending on the pattern.
568    
569    4.  Caseless matching was not working for non-ASCII characters in back
570        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
571        It now works when Unicode Property Support is available.
572    
573    5.  In pcretest, an escape such as \x{de} in the data was always generating
574        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
575        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
576        truncation.
577    
578    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
579    
580    7.  Added two (int) casts to pcregrep when printing the difference of two
581        pointers, in case they are 64-bit values.
582    
583    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
584        test 2 if it fails.
585    
586    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
587        and a #define of that name to empty if it is not externally set. This is to
588        allow users of MSVC to set it if necessary.
589    
590    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
591        the convenience functions in the pcre_get.c source file.
592    
593    11. An option change at the start of a pattern that had top-level alternatives
594        could cause overwriting and/or a crash. This command provoked a crash in
595        some environments:
596    
597          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
598    
599        This potential security problem was recorded as CVE-2008-2371.
600    
601    12. For a pattern where the match had to start at the beginning or immediately
602        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
603        pcre_dfa_exec() could read past the end of the passed subject if there was
604        no match. To help with detecting such bugs (e.g. with valgrind), I modified
605        pcretest so that it places the subject at the end of its malloc-ed buffer.
606    
607    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
608        exec() might read past the end of the data buffer in UTF-8 mode.
609    
610    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
611        the data contained the byte 0x85 as part of a UTF-8 character within its
612        first line. This applied both to normal and DFA matching.
613    
614    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
615        /^[^d]*?$/8 failed to match "abc".
616    
617    16. Added a missing copyright notice to pcrecpp_internal.h.
618    
619    17. Make it more clear in the documentation that values returned from
620        pcre_exec() in ovector are byte offsets, not character counts.
621    
622    18. Tidied a few places to stop certain compilers from issuing warnings.
623    
624    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
625        supplied by Stefan Weber. I made a further small update for 7.8 because
626        there is a change of source arrangements: the pcre_searchfuncs.c module is
627        replaced by pcre_ucd.c.
628    
629    
630    Version 7.7 07-May-08
631    ---------------------
632    
633    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
634        a string to a long long, pretend we don't even have a long long." This is
635        done by checking for the strtoq, strtoll, and _strtoi64 functions.
636    
637    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
638        pre-7.6 versions, which defined a global no_arg variable instead of putting
639        it in the RE class. (See also #8 below.)
640    
641    3.  Remove a line of dead code, identified by coverity and reported by Nuno
642        Lopes.
643    
644    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
645    
646        (1) The include/exclude patterns were being applied to the whole pathnames
647            of files, instead of just to the final components.
648    
649        (2) If there was more than one level of directory, the subdirectories were
650            skipped unless they satisfied the include/exclude conditions. This is
651            inconsistent with GNU grep (and could even be seen as contrary to the
652            pcregrep specification - which I improved to make it absolutely clear).
653            The action now is always to scan all levels of directory, and just
654            apply the include/exclude patterns to regular files.
655    
656    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
657        --exclude_dir in the tests to avoid scanning .svn directories.
658    
659    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
660        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
661        doesn't support NULs in patterns.
662    
663    7.  Added some missing "const"s to declarations of static tables in
664        pcre_compile.c and pcre_dfa_exec.c.
665    
666    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
667        caused by fix #2  above. (Subsequently also a second patch to fix the
668        first patch. And a third patch - this was a messy problem.)
669    
670    9.  Applied Craig's patch to remove the use of push_back().
671    
672    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
673        matching function regexec().
674    
675    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
676        which, however, unlike Perl's \g{...}, are subroutine calls, not back
677        references. PCRE supports relative numbers with this syntax (I don't think
678        Oniguruma does).
679    
680    12. Previously, a group with a zero repeat such as (...){0} was completely
681        omitted from the compiled regex. However, this means that if the group
682        was called as a subroutine from elsewhere in the pattern, things went wrong
683        (an internal error was given). Such groups are now left in the compiled
684        pattern, with a new opcode that causes them to be skipped at execution
685        time.
686    
687    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
688        to the way PCRE behaves:
689    
690        (a) A lone ] character is dis-allowed (Perl treats it as data).
691    
692        (b) A back reference to an unmatched subpattern matches an empty string
693            (Perl fails the current match path).
694    
695        (c) A data ] in a character class must be notated as \] because if the
696            first data character in a class is ], it defines an empty class. (In
697            Perl it is not possible to have an empty class.) The empty class []
698            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
699            The negative empty class [^] matches any one character, independently
700            of the DOTALL setting.
701    
702    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
703        non-existent subpattern following a character class starting with ']' and
704        containing () gave an internal compiling error instead of "reference to
705        non-existent subpattern". Fortunately, when the pattern did exist, the
706        compiled code was correct. (When scanning forwards to check for the
707        existencd of the subpattern, it was treating the data ']' as terminating
708        the class, so got the count wrong. When actually compiling, the reference
709        was subsequently set up correctly.)
710    
711    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
712        it was being rejected as not supported by pcre_dfa_exec(), even though
713        other assertions are supported. I have made pcre_dfa_exec() support
714        (*FAIL).
715    
716    16. The implementation of 13c above involved the invention of a new opcode,
717        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
718        cannot be changed at match time, I realized I could make a small
719        improvement to matching performance by compiling OP_ALLANY instead of
720        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
721        on the OP_ANY path.
722    
723    17. Compiling pcretest on Windows with readline support failed without the
724        following two fixes: (1) Make the unistd.h include conditional on
725        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
726    
727    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
728        ncurses library to be included for pcretest when ReadLine support is
729        requested, but also to allow for it to be overridden. This patch came from
730        Daniel Bergström.
731    
732    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
733        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
734        any errors with the current Unicode tables. Thanks to Peter Kankowski for
735        spotting this.
736    
737    
738    Version 7.6 28-Jan-08
739  ---------------------  ---------------------
740    
741   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one  1.  A character class containing a very large number of characters with
742      that is more "standard", making use of automake and other autotools. There      codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
743        overflow.
744    
745    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
746        HAVE_LONG_LONG is not defined.
747    
748    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
749        bring them up to date and include new features. This patch includes:
750    
751        - Fixed PH's badly added libz and libbz2 support.
752        - Fixed a problem with static linking.
753        - Added pcredemo. [But later removed - see 7 below.]
754        - Fixed dftables problem and added an option.
755        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
756            HAVE_LONG_LONG.
757        - Added readline support for pcretest.
758        - Added an listing of the option settings after cmake has run.
759    
760    4.  A user submitted a patch to Makefile that makes it easy to create
761        "pcre.dll" under mingw when using Configure/Make. I added stuff to
762        Makefile.am that cause it to include this special target, without
763        affecting anything else. Note that the same mingw target plus all
764        the other distribution libraries and programs are now supported
765        when configuring with CMake (see 6 below) instead of with
766        Configure/Make.
767    
768    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
769        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
770        exported in the Windows port". It has not yet been confirmed that the patch
771        solves the problem, but it does no harm.
772    
773    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
774        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
775        with CMake, and also correct the comment about stack recursion.
776    
777    7.  Remove the automatic building of pcredemo from the ./configure system and
778        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
779        of a program that users should build themselves after PCRE is installed, so
780        building it automatically is not really right. What is more, it gave
781        trouble in some build environments.
782    
783    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
784    
785    
786    Version 7.5 10-Jan-08
787    ---------------------
788    
789    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
790        values in parens when parsing an RE using the C++ wrapper."
791    
792    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
793        Characters greater than 255 were excluded from the class instead of being
794        included.
795    
796    3.  The same bug as (2) above applied to negated POSIX classes such as
797        [:^space:].
798    
799    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
800        defined or documented. It seems to have been a typo for PCRE_STATIC, so
801        I have changed it.
802    
803    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
804        first named subpattern) and a construct such as (?&a) would reference the
805        first named subpattern whose name started with "a" (in other words, the
806        length check was missing). Both these problems are fixed. "Subpattern name
807        expected" is now given for (?&) (a zero-length name), and this patch also
808        makes it give the same error for \k'' (previously it complained that that
809        was a reference to a non-existent subpattern).
810    
811    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
812        this is right because (?- can be followed by option settings as well as by
813        digits. I have, however, made the messages clearer.
814    
815    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
816        than the number used in the conditional) now cause a compile-time error.
817        This is actually not compatible with Perl, which accepts such patterns, but
818        treats the conditional as always being FALSE (as PCRE used to), but it
819        seems to me that giving a diagnostic is better.
820    
821    8.  Change "alphameric" to the more common word "alphanumeric" in comments
822        and messages.
823    
824    9.  Fix two occurrences of "backslash" in comments that should have been
825        "backspace".
826    
827    10. Remove two redundant lines of code that can never be obeyed (their function
828        was moved elsewhere).
829    
830    11. The program that makes PCRE's Unicode character property table had a bug
831        which caused it to generate incorrect table entries for sequences of
832        characters that have the same character type, but are in different scripts.
833        It amalgamated them into a single range, with the script of the first of
834        them. In other words, some characters were in the wrong script. There were
835        thirteen such cases, affecting characters in the following ranges:
836    
837          U+002b0 - U+002c1
838          U+0060c - U+0060d
839          U+0061e - U+00612
840          U+0064b - U+0065e
841          U+0074d - U+0076d
842          U+01800 - U+01805
843          U+01d00 - U+01d77
844          U+01d9b - U+01dbf
845          U+0200b - U+0200f
846          U+030fc - U+030fe
847          U+03260 - U+0327f
848          U+0fb46 - U+0fbb1
849          U+10450 - U+1049d
850    
851    12. The -o option (show only the matching part of a line) for pcregrep was not
852        compatible with GNU grep in that, if there was more than one match in a
853        line, it showed only the first of them. It now behaves in the same way as
854        GNU grep.
855    
856    13. If the -o and -v options were combined for pcregrep, it printed a blank
857        line for every non-matching line. GNU grep prints nothing, and pcregrep now
858        does the same. The return code can be used to tell if there were any
859        non-matching lines.
860    
861    14. Added --file-offsets and --line-offsets to pcregrep.
862    
863    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
864        infinitely looping recursion. The bug was that positive lookaheads were not
865        being skipped when checking for a possible empty match (negative lookaheads
866        and both kinds of lookbehind were skipped).
867    
868    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
869        inclusion of <windows.h> to before rather than after the definition of
870        INVALID_FILE_ATTRIBUTES (patch from David Byron).
871    
872    17. Specifying a possessive quantifier with a specific limit for a Unicode
873        character property caused pcre_compile() to compile bad code, which led at
874        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
875        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
876        caused the error; without that there was no problem.
877    
878    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
879    
880    19. Added --enable-pcretest-libreadline.
881    
882    20. In pcrecpp.cc, the variable 'count' was incremented twice in
883        RE::GlobalReplace(). As a result, the number of replacements returned was
884        double what it should be. I removed one of the increments, but Craig sent a
885        later patch that removed the other one (the right fix) and added unit tests
886        that check the return values (which was not done before).
887    
888    21. Several CMake things:
889    
890        (1) Arranged that, when cmake is used on Unix, the libraries end up with
891            the names libpcre and libpcreposix, not just pcre and pcreposix.
892    
893        (2) The above change means that pcretest and pcregrep are now correctly
894            linked with the newly-built libraries, not previously installed ones.
895    
896        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
897    
898    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
899        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
900        UTF-8 newline character). The key issue is that the pattern starts .*;
901        this means that the match must be either at the beginning, or after a
902        newline. The bug was in the code for advancing after a failed match and
903        checking that the new position followed a newline. It was not taking
904        account of UTF-8 characters correctly.
905    
906    23. PCRE was behaving differently from Perl in the way it recognized POSIX
907        character classes. PCRE was not treating the sequence [:...:] as a
908        character class unless the ... were all letters. Perl, however, seems to
909        allow any characters between [: and :], though of course it rejects as
910        unknown any "names" that contain non-letters, because all the known class
911        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
912        for example, whereas PCRE did not - it did not recognize a POSIX character
913        class. This seemed a bit dangerous, so the code has been changed to be
914        closer to Perl. The behaviour is not identical to Perl, because PCRE will
915        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
916        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
917        Perl does, and where it didn't before.
918    
919    24. Rewrite so as to remove the single use of %n from pcregrep because in some
920        Windows environments %n is disabled by default.
921    
922    
923    Version 7.4 21-Sep-07
924    ---------------------
925    
926    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
927        means that a class such as [\s] counted as "explicit reference to CR or
928        LF". That isn't really right - the whole point of the change was to try to
929        help when there was an actual mention of one of the two characters. So now
930        the change happens only if \r or \n (or a literal CR or LF) character is
931        encountered.
932    
933    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
934        of both had grown to the point where there were only 3 bits left.
935        Fortunately, there was spare space in the data structure, and so I have
936        moved the internal flags into a new 16-bit field to free up more option
937        bits.
938    
939    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
940        but did not set the internal JCHANGED flag - either of these is enough to
941        control the way the "get" function works - but the PCRE_INFO_JCHANGED
942        facility is supposed to tell if (?J) was ever used, so now (?J) at the
943        start sets both bits.
944    
945    4.  Added options (at build time, compile time, exec time) to change \R from
946        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
947    
948    5.  doc/pcresyntax.html was missing from the distribution.
949    
950    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
951        compatibility, even though it is no longer used.
952    
953    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
954        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
955        windows.h file is present (where different names are used). [This was
956        reversed later after testing - see 16 below.]
957    
958    8.  Changed all #include <config.h> to #include "config.h". There were also
959        some further <pcre.h> cases that I changed to "pcre.h".
960    
961    9.  When pcregrep was used with the --colour option, it missed the line ending
962        sequence off the lines that it output.
963    
964    10. It was pointed out to me that arrays of string pointers cause lots of
965        relocations when a shared library is dynamically loaded. A technique of
966        using a single long string with a table of offsets can drastically reduce
967        these. I have refactored PCRE in four places to do this. The result is
968        dramatic:
969    
970          Originally:                          290
971          After changing UCP table:            187
972          After changing error message table:   43
973          After changing table of "verbs"       36
974          After changing table of Posix names   22
975    
976        Thanks to the folks working on Gregex for glib for this insight.
977    
978    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
979        unicode-properties was also set.
980    
981    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
982    
983    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
984        checked only for CRLF.
985    
986    14. Added casts to pcretest.c to avoid compiler warnings.
987    
988    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
989    
990    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
991        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
992        entirely. This removes changes made in 7 above.
993    
994    17. The CMake files have been updated, and there is now more information about
995        building with CMake in the NON-UNIX-USE document.
996    
997    
998    Version 7.3 28-Aug-07
999    ---------------------
1000    
1001     1. In the rejigging of the build system that eventually resulted in 7.1, the
1002        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1003        brackets there is not right, since it causes compilers to look for an
1004        installed pcre.h, not the version that is in the source that is being
1005        compiled (which of course may be different). I have changed it back to:
1006    
1007          #include "pcre.h"
1008    
1009        I have a vague recollection that the change was concerned with compiling in
1010        different directories, but in the new build system, that is taken care of
1011        by the VPATH setting the Makefile.
1012    
1013     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1014        when the subject happened to end in the byte 0x85 (e.g. if the last
1015        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1016        characters but of course it shouldn't be taken as a newline when it is part
1017        of another character. The bug was that, for an unlimited repeat of . in
1018        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1019        characters when looking for a newline.
1020    
1021     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1022    
1023     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1024        in debug output.
1025    
1026     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1027        long printing in the pcrecpp unittest when running under MinGW.
1028    
1029     6. ESC_K was left out of the EBCDIC table.
1030    
1031     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1032        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1033        limit also applies to "virtual nesting" when a pattern is recursive, and in
1034        this case 1000 isn't so big. I have been able to remove this limit at the
1035        expense of backing off one optimization in certain circumstances. Normally,
1036        when pcre_exec() would call its internal match() function recursively and
1037        immediately return the result unconditionally, it uses a "tail recursion"
1038        feature to save stack. However, when a subpattern that can match an empty
1039        string has an unlimited repetition quantifier, it no longer makes this
1040        optimization. That gives it a stack frame in which to save the data for
1041        checking that an empty string has been matched. Previously this was taken
1042        from the 1000-entry workspace that had been reserved. So now there is no
1043        explicit limit, but more stack is used.
1044    
1045     8. Applied Daniel's patches to solve problems with the import/export magic
1046        syntax that is required for Windows, and which was going wrong for the
1047        pcreposix and pcrecpp parts of the library. These were overlooked when this
1048        problem was solved for the main library.
1049    
1050     9. There were some crude static tests to avoid integer overflow when computing
1051        the size of patterns that contain repeated groups with explicit upper
1052        limits. As the maximum quantifier is 65535, the maximum group length was
1053        set at 30,000 so that the product of these two numbers did not overflow a
1054        32-bit integer. However, it turns out that people want to use groups that
1055        are longer than 30,000 bytes (though not repeat them that many times).
1056        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1057        made it possible to implement the integer overflow checks in a much more
1058        dynamic way, which I have now done. The artificial limitation on group
1059        length has been removed - we now have only the limit on the total length of
1060        the compiled pattern, which depends on the LINK_SIZE setting.
1061    
1062    10. Fixed a bug in the documentation for get/copy named substring when
1063        duplicate names are permitted. If none of the named substrings are set, the
1064        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1065        empty string.
1066    
1067    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1068        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1069        because the ] is interpreted as the first data character and the
1070        terminating ] is not found. PCRE has been made compatible with Perl in this
1071        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1072        cause memory overwriting.
1073    
1074    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1075        string has been matched (to stop an infinite loop). It was not recognizing
1076        a conditional subpattern that could match an empty string if that
1077        subpattern was within another subpattern. For example, it looped when
1078        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1079        condition was not nested. This bug has been fixed.
1080    
1081    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1082        past the start of the subject in the presence of bytes with the top bit
1083        set, for example "\x8aBCD".
1084    
1085    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1086        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1087    
1088    14. Optimized (?!) to (*FAIL).
1089    
1090    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1091        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1092        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1093        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1094        does: it's just the validity check that is more restrictive.
1095    
1096    16. Inserted checks for integer overflows during escape sequence (backslash)
1097        processing, and also fixed erroneous offset values for syntax errors during
1098        backslash processing.
1099    
1100    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1101        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1102    
1103    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1104        caused an overrun.
1105    
1106    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1107        something other than just ASCII characters) inside a group that had an
1108        unlimited repeat caused a loop at compile time (while checking to see
1109        whether the group could match an empty string).
1110    
1111    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1112        [\P{Any}] did so. (Error in the code for printing property names.)
1113    
1114    21. An orphan \E inside a character class could cause a crash.
1115    
1116    22. A repeated capturing bracket such as (A)? could cause a wild memory
1117        reference during compilation.
1118    
1119    23. There are several functions in pcre_compile() that scan along a compiled
1120        expression for various reasons (e.g. to see if it's fixed length for look
1121        behind). There were bugs in these functions when a repeated \p or \P was
1122        present in the pattern. These operators have additional parameters compared
1123        with \d, etc, and these were not being taken into account when moving along
1124        the compiled data. Specifically:
1125    
1126        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1127            length.
1128    
1129        (b) An item such as \pL+ within a repeated group could cause crashes or
1130            loops.
1131    
1132        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1133            "reference to non-existent subpattern" error.
1134    
1135        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1136    
1137    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1138        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1139    
1140    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1141    
1142    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1143        character were causing crashes (broken optimization).
1144    
1145    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1146        \p or \P) caused a compile-time loop.
1147    
1148    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1149        break. For example, the unstudied pattern [\r\n]A does not match the string
1150        "\r\nA" because change 7.0/46 below moves the current point on by two
1151        characters after failing to match at the start. However, the pattern \nA
1152        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1153        the same is true. There doesn't seem any very clean way out of this, but
1154        what I have chosen to do makes the common cases work: PCRE now takes note
1155        of whether there can be an explicit match for \r or \n anywhere in the
1156        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1157        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1158        pattern has explicit CR or LF references.
1159    
1160    29. Added (*CR) etc for changing newline setting at start of pattern.
1161    
1162    
1163    Version 7.2 19-Jun-07
1164    ---------------------
1165    
1166     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1167        which is apparently normally available under Windows.
1168    
1169     2. Re-jig the pcregrep tests with different newline settings in an attempt
1170        to make them independent of the local environment's newline setting.
1171    
1172     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1173    
1174     4. Some of the "internals" tests were previously cut out when the link size
1175        was not 2, because the output contained actual offsets. The recent new
1176        "Z" feature of pcretest means that these can be cut out, making the tests
1177        usable with all link sizes.
1178    
1179     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1180        stack recursion. This gives a massive performance boost under BSD, but just
1181        a small improvement under Linux. However, it saves one field in the frame
1182        in all cases.
1183    
1184     6. Added more features from the forthcoming Perl 5.10:
1185    
1186        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1187            recursion call. It refers to the nth most recently opened parentheses.
1188    
1189        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1190            to be opened parentheses.
1191    
1192        (c) Conditions that refer to capturing parentheses can be specified
1193            relatively, for example, (?(-2)... or (?(+3)...
1194    
1195        (d) \K resets the start of the current match so that everything before
1196            is not part of it.
1197    
1198        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1199    
1200        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1201            reference syntax.
1202    
1203        (g) (?| introduces a group in which the numbering of parentheses in each
1204            alternative starts with the same number.
1205    
1206        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1207    
1208     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1209        PCRE_INFO_JCHANGED.
1210    
1211     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1212        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1213        for detecting groups that can match an empty string.
1214    
1215     9. A pattern with a very large number of alternatives (more than several
1216        hundred) was running out of internal workspace during the pre-compile
1217        phase, where pcre_compile() figures out how much memory will be needed. A
1218        bit of new cunning has reduced the workspace needed for groups with
1219        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1220        workspace instead of running out of the 4096 that are available.
1221    
1222    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1223    
1224    11. Applied patch from Google to remove an optimization that didn't quite work.
1225        The report of the bug said:
1226    
1227          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1228          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1229          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1230    
1231    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1232        it matched the wrong number of bytes.
1233    
1234    
1235    Version 7.1 24-Apr-07
1236    ---------------------
1237    
1238     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1239        that is more "standard", making use of automake and other Autotools. There
1240      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
1241      on this.      on this.
1242    
1243   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1244      for recursive directory scanning broke on some systems because the files      for recursive directory scanning broke on some systems because the files
1245      are not scanned in any specific order and on different systems the order      are not scanned in any specific order and on different systems the order
1246      was different. A call to "sort" has been inserted into RunGrepTest for the      was different. A call to "sort" has been inserted into RunGrepTest for the
1247      approprate test as a short-term fix. In the longer term there may be an      approprate test as a short-term fix. In the longer term there may be an
1248      alternative.      alternative.
1249    
1250   3. I had an email from Eric Raymond about problems translating some of PCRE's   3. I had an email from Eric Raymond about problems translating some of PCRE's
1251      man pages to HTML (despite the fact that I distribute HTML pages, some      man pages to HTML (despite the fact that I distribute HTML pages, some
1252      people do their own conversions for various reasons). The problems      people do their own conversions for various reasons). The problems
1253      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
1254      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
1255      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
1256      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
1257      encounters .br or .in.      .br or .in.
1258    
1259   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
1260      arranged for config.h to be included in the distribution, for the benefit      arranged for config.h to be included in the distribution, with the name
1261      of those who have to compile without Autotools (compare pcre.h).      config.h.generic, for the benefit of those who have to compile without
1262        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1263   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan  
1264      Weber: (1) pcre_internal.h was missing some function renames; (2) updated   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1265      makevp.bat for the current PCRE, using the additional files !compile.txt,      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1266      !linklib.txt, and pcregexp.pas.      makevp.bat for the current PCRE, using the additional files
1267        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1268   6. A Windows user reported a minor discrepancy with test 2, which turned out  
1269      to be caused by a trailing space on an input line that had got lost in his   6. A Windows user reported a minor discrepancy with test 2, which turned out
1270        to be caused by a trailing space on an input line that had got lost in his
1271      copy. The trailing space was an accident, so I've just removed it.      copy. The trailing space was an accident, so I've just removed it.
1272    
1273   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1274      that is needed.      that is needed.
1275    
1276   8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)   8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1277      as "const" (a) because they are and (b) because it helps the PHP      as "const" (a) because they are and (b) because it helps the PHP
1278      maintainers who have recently made a script to detect big data structures      maintainers who have recently made a script to detect big data structures
1279      in the php code that should be moved to the .rodata section. I remembered      in the php code that should be moved to the .rodata section. I remembered
1280      to update Builducptable as well, so it won't revert if ucptable.h is ever      to update Builducptable as well, so it won't revert if ucptable.h is ever
1281      re-created.      re-created.
1282    
1283   9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,   9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1284      pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in      pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1285      order to be able to cut out the UTF-8 tables in the latter when UTF-8      order to be able to cut out the UTF-8 tables in the latter when UTF-8
1286      support is not required. This saves 1.5-2K of code, which is important in      support is not required. This saves 1.5-2K of code, which is important in
1287      some applications.      some applications.
1288    
1289  10. The emulated memmove() function in pcre_internal.h (provided for those      Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1290      environments that have neither memmove() nor bcopy()) was defining its      so as not to refer to the tables, even though these functions will never be
1291      arguments as char * instead of void *.      called when UTF-8 support is disabled. Otherwise there are problems with a
1292        shared library.
1293    
1294    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1295    
1296        (a) It was defining its arguments as char * instead of void *.
1297    
1298        (b) It was assuming that all moves were upwards in memory; this was true
1299            a long time ago when I wrote it, but is no longer the case.
1300    
1301        The emulated memove() is provided for those environments that have neither
1302        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1303        is clearly not the case, as these two bugs were recently reported.
1304    
1305    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1306        and Detrail to create the HTML documentation, the .txt form of the man
1307        pages, and it removes trailing spaces from listed files. It also creates
1308        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1309        case, it wraps all the #defines with #ifndefs. This script should be run
1310        before "make dist".
1311    
1312    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1313        with Unicode property support.
1314    
1315        (a) For a maximizing quantifier, if the two different cases of the
1316            character were of different lengths in their UTF-8 codings (there are
1317            some cases like this - I found 11), and the matching function had to
1318            back up over a mixture of the two cases, it incorrectly assumed they
1319            were both the same length.
1320    
1321        (b) When PCRE was configured to use the heap rather than the stack for
1322            recursion during matching, it was not correctly preserving the data for
1323            the other case of a UTF-8 character when checking ahead for a match
1324            while processing a minimizing repeat. If the check also involved
1325            matching a wide character, but failed, corruption could cause an
1326            erroneous result when trying to check for a repeat of the original
1327            character.
1328    
1329    13. Some tidying changes to the testing mechanism:
1330    
1331        (a) The RunTest script now detects the internal link size and whether there
1332            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1333            values substituted by "configure". (The RunGrepTest script already did
1334            this for UTF-8.) The configure.ac script no longer substitutes the
1335            relevant variables.
1336    
1337        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1338            with length and offset values. This means that the output is different
1339            for different internal link sizes. Test 2 is skipped for link sizes
1340            other than 2 because of this, bypassing the problem. Unfortunately,
1341            there was also a test in test 3 (the locale tests) that used /B and
1342            failed for link sizes other than 2. Rather than cut the whole test out,
1343            I have added a new /Z option to pcretest that replaces the length and
1344            offset values with spaces. This is now used to make test 3 independent
1345            of link size. (Test 2 will be tidied up later.)
1346    
1347    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1348        segmentation fault instead of returning the appropriate error message.
1349    
1350    15. In multiline mode when the newline sequence was set to "any", the pattern
1351        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1352        This doesn't seem right; it now treats the CRLF combination as the line
1353        ending, and so does not match in that case. It's only a pattern such as ^$
1354        that would hit this one: something like ^ABC$ would have failed after \r
1355        and then tried again after \r\n.
1356    
1357    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1358        in an attempt to make files that differ only in their line terminators
1359        compare equal. This works on Linux.
1360    
1361    17. Under certain error circumstances pcregrep might try to free random memory
1362        as it exited. This is now fixed, thanks to valgrind.
1363    
1364    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1365        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1366        was because its rules for how to advance for /g after matching an empty
1367        string at the end of a line did not allow for this case. They now check for
1368        it specially.
1369    
1370    20. pcretest is supposed to handle patterns and data of any length, by
1371        extending its buffers when necessary. It was getting this wrong when the
1372        buffer for a data line had to be extended.
1373    
1374    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1375        CRLF as a newline sequence.
1376    
1377    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1378        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1379        I have nevertheless tidied it up.
1380    
1381    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1382    
1383    24. Added a man page for pcre-config.
1384    
1385    
1386  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1387  ---------------------  ---------------------

Legend:
Removed from v.108  
changed lines
  Added in v.530

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12