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

Diff of /code/trunk/ChangeLog

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

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

Legend:
Removed from v.190  
changed lines
  Added in v.531

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12