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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.6 21-Jan-08  Version 8.12 12-Jan-2011
5    ------------------------
6    
7    1.  Fixed some typos in the markup of the man pages, and wrote a script that
8        checks for such things as part of the documentation building process.
9    
10    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
11        --match-limit and --recursion-limit options (added for 8.11). In
12        particular, this made one of the standard tests crash. (The integer value
13        went into the wrong half of a long int.)
14    
15    3.  If the --colour option was given to pcregrep with -v (invert match), it
16        did strange things, either producing crazy output, or crashing. It should,
17        of course, ignore a request for colour when reporting lines that do not
18        match.
19    
20    
21    Version 8.11 10-Dec-2010
22    ------------------------
23    
24    1.  (*THEN) was not working properly if there were untried alternatives prior
25        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
26        backtracked to try for "b" instead of moving to the next alternative branch
27        at the same level (in this case, to look for "c"). The Perl documentation
28        is clear that when (*THEN) is backtracked onto, it goes to the "next
29        alternative in the innermost enclosing group".
30    
31    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
32        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
33        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
34        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
35        (*THEN).
36    
37    3.  If \s appeared in a character class, it removed the VT character from
38        the class, even if it had been included by some previous item, for example
39        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
40        of \s, but is part of the POSIX "space" class.)
41    
42    4.  A partial match never returns an empty string (because you can always
43        match an empty string at the end of the subject); however the checking for
44        an empty string was starting at the "start of match" point. This has been
45        changed to the "earliest inspected character" point, because the returned
46        data for a partial match starts at this character. This means that, for
47        example, /(?<=abc)def/ gives a partial match for the subject "abc"
48        (previously it gave "no match").
49    
50    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
51        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
52        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
53        has an implication that the given string is incomplete (because a partial
54        match is preferred over a full match). For this reason, these items now
55        give a partial match in this situation. [Aside: previously, the one case
56        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
57        match rather than a full match, which was wrong by the old rules, but is
58        now correct.]
59    
60    6.  There was a bug in the handling of #-introduced comments, recognized when
61        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
62        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
63        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
64        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
65        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
66        places in pcre_compile().
67    
68    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
69        comments when looking ahead for named forward references to subpatterns,
70        the only newline sequence it recognized was NL. It now handles newlines
71        according to the set newline convention.
72    
73    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
74        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
75        cater for a lack of strerror(). These oversights have been fixed.
76    
77    9.  Added --match-limit and --recursion-limit to pcregrep.
78    
79    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
80    
81    11. When the -o option was used, pcregrep was setting a return code of 1, even
82        when matches were found, and --line-buffered was not being honoured.
83    
84    12. Added an optional parentheses number to the -o and --only-matching options
85        of pcregrep.
86    
87    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
88        can match an empty string. The code to do it in pcretest and pcredemo
89        needed fixing:
90    
91        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
92            only one byte after an empty string match just before CRLF (this case
93            just got forgotten; "any" and "anycrlf" were OK).
94    
95        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
96            mode when an empty string match preceded an ASCII character followed by
97            a non-ASCII character. (The code for advancing by one character rather
98            than one byte was nonsense.)
99    
100        (c) The pcredemo.c sample program did not have any code at all to handle
101            the cases when CRLF is a valid newline sequence.
102    
103    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
104        as a starting offset was within the subject string. There is now a new
105        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
106        negative or greater than the length of the string. In order to test this,
107        pcretest is extended to allow the setting of negative starting offsets.
108    
109    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
110        starting offset points to the beginning of a UTF-8 character was
111        unnecessarily clumsy. I tidied it up.
112    
113    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
114        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
115    
116    17. Nobody had reported that the --include_dir option, which was added in
117        release 7.7 should have been called --include-dir (hyphen, not underscore)
118        for compatibility with GNU grep. I have changed it to --include-dir, but
119        left --include_dir as an undocumented synonym, and the same for
120        --exclude-dir, though that is not available in GNU grep, at least as of
121        release 2.5.4.
122    
123    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
124        characters from a string of bytes) have been redefined so as not to use
125        loops, in order to improve performance in some environments. At the same
126        time, I abstracted some of the common code into auxiliary macros to save
127        repetition (this should not affect the compiled code).
128    
129    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
130        compile-time error is now given if \c is not followed by an ASCII
131        character, that is, a byte less than 128. (In EBCDIC mode, the code is
132        different, and any byte value is allowed.)
133    
134    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
135        START_OPTIMIZE option, which is now allowed at compile time - but just
136        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
137        to pcregrep and other applications that have no direct access to PCRE
138        options. The new /Y option in pcretest sets this option when calling
139        pcre_compile().
140    
141    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
142        back references. Groups containing recursive back references were forced to
143        be atomic by that change, but in the case of named groups, the amount of
144        memory required was incorrectly computed, leading to "Failed: internal
145        error: code overflow". This has been fixed.
146    
147    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
148        pcretest.c, to avoid build problems in some Borland environments.
149    
150    
151    Version 8.10 25-Jun-2010
152    ------------------------
153    
154    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
155        THEN.
156    
157    2.  (*ACCEPT) was not working when inside an atomic group.
158    
159    3.  Inside a character class, \B is treated as a literal by default, but
160        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
161        causes the error). The code is unchanged, but I tidied the documentation.
162    
163    4.  Inside a character class, PCRE always treated \R and \X as literals,
164        whereas Perl faults them if its -w option is set. I have changed PCRE so
165        that it faults them when PCRE_EXTRA is set.
166    
167    5.  Added support for \N, which always matches any character other than
168        newline. (It is the same as "." when PCRE_DOTALL is not set.)
169    
170    6.  When compiling pcregrep with newer versions of gcc which may have
171        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
172        declared with attribute warn_unused_result" were given. Just casting the
173        result to (void) does not stop the warnings; a more elaborate fudge is
174        needed. I've used a macro to implement this.
175    
176    7.  Minor change to pcretest.c to avoid a compiler warning.
177    
178    8.  Added four artifical Unicode properties to help with an option to make
179        \s etc use properties (see next item). The new properties are: Xan
180        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
181    
182    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
183        use Unicode properties. (*UCP) at the start of a pattern can be used to set
184        this option. Modified pcretest to add /W to test this facility. Added
185        REG_UCP to make it available via the POSIX interface.
186    
187    10. Added --line-buffered to pcregrep.
188    
189    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
190        studied, and the match started with a letter with a code point greater than
191        127 whose first byte was different to the first byte of the other case of
192        the letter, the other case of this starting letter was not recognized
193        (#976).
194    
195    12. If a pattern that was studied started with a repeated Unicode property
196        test, for example, \p{Nd}+, there was the theoretical possibility of
197        setting up an incorrect bitmap of starting bytes, but fortunately it could
198        not have actually happened in practice until change 8 above was made (it
199        added property types that matched character-matching opcodes).
200    
201    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
202        possible starting bytes for non-anchored patterns.
203    
204    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
205        \R, and also a number of cases that involve Unicode properties, both
206        explicit and implicit when PCRE_UCP is set.
207    
208    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
209        input, it could crash or give wrong results if characters with values
210        greater than 0xc0 were present in the subject string. (Detail: it assumed
211        UTF-8 input when processing these items.)
212    
213    16. Added a lot of (int) casts to avoid compiler warnings in systems where
214        size_t is 64-bit (#991).
215    
216    17. Added a check for running out of memory when PCRE is compiled with
217        --disable-stack-for-recursion (#990).
218    
219    18. If the last data line in a file for pcretest does not have a newline on
220        the end, a newline was missing in the output.
221    
222    19. The default pcre_chartables.c file recognizes only ASCII characters (values
223        less than 128) in its various bitmaps. However, there is a facility for
224        generating tables according to the current locale when PCRE is compiled. It
225        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
226        characters, are recognized by isspace() and therefore were getting set in
227        these tables, and indeed these tables seem to approximate to ISO 8859. This
228        caused a problem in UTF-8 mode when pcre_study() was used to create a list
229        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
230        which of course cannot start UTF-8 characters. I have changed the code so
231        that only real ASCII characters (less than 128) and the correct starting
232        bytes for UTF-8 encodings are set for characters greater than 127 when in
233        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
234        altogether.)
235    
236    20. Added the /T option to pcretest so as to be able to run tests with non-
237        standard character tables, thus making it possible to include the tests
238        used for 19 above in the standard set of tests.
239    
240    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
241        reference to a subpattern the other side of a comment that contains an
242        opening parenthesis caused either an internal compiling error, or a
243        reference to the wrong subpattern.
244    
245    
246    Version 8.02 19-Mar-2010
247    ------------------------
248    
249    1.  The Unicode data tables have been updated to Unicode 5.2.0.
250    
251    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
252        configured.
253    
254    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
255        original author of that file, following a query about its status.
256    
257    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
258        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
259    
260    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
261        quantifier applied to a forward-referencing subroutine call, could compile
262        incorrect code or give the error "internal error: previously-checked
263        referenced subpattern not found".
264    
265    6.  Both MS Visual Studio and Symbian OS have problems with initializing
266        variables to point to external functions. For these systems, therefore,
267        pcre_malloc etc. are now initialized to local functions that call the
268        relevant global functions.
269    
270    7.  There were two entries missing in the vectors called coptable and poptable
271        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
272        I've fixed the data, and added a kludgy way of testing at compile time that
273        the lengths are correct (equal to the number of opcodes).
274    
275    8.  Following on from 7, I added a similar kludge to check the length of the
276        eint vector in pcreposix.c.
277    
278    9.  Error texts for pcre_compile() are held as one long string to avoid too
279        much relocation at load time. To find a text, the string is searched,
280        counting zeros. There was no check for running off the end of the string,
281        which could happen if a new error number was added without updating the
282        string.
283    
284    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
285    
286    11. \K was not working if it appeared in an atomic group or in a group that
287        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
288        \K is "not well defined" if used in an assertion. PCRE now accepts it if
289        the assertion is positive, but not if it is negative.
290    
291    12. Change 11 fortuitously reduced the size of the stack frame used in the
292        "match()" function of pcre_exec.c by one pointer. Forthcoming
293        implementation of support for (*MARK) will need an extra pointer on the
294        stack; I have reserved it now, so that the stack frame size does not
295        decrease.
296    
297    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
298        item in branch that calls a recursion is a subroutine call - as in the
299        second branch in the above example - was incorrectly given the compile-
300        time error "recursive call could loop indefinitely" because pcre_compile()
301        was not correctly checking the subroutine for matching a non-empty string.
302    
303    14. The checks for overrunning compiling workspace could trigger after an
304        overrun had occurred. This is a "should never occur" error, but it can be
305        triggered by pathological patterns such as hundreds of nested parentheses.
306        The checks now trigger 100 bytes before the end of the workspace.
307    
308    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
309    
310    
311    Version 8.01 19-Jan-2010
312    ------------------------
313    
314    1.  If a pattern contained a conditional subpattern with only one branch (in
315        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
316        computed the wrong minimum data length (which is of course zero for such
317        subpatterns). This could cause incorrect "no match" results.
318    
319    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
320        the pattern is reset in the first branch, pcre_compile() failed with
321        "internal error: code overflow at offset...". This happened only when
322        the reset was to the original external option setting. (An optimization
323        abstracts leading options settings into an external setting, which was the
324        cause of this.)
325    
326    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
327        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
328        assertion pattern did not match (meaning that the assertion was true), it
329        was incorrectly treated as false if the SKIP had been reached during the
330        matching. This also applied to assertions used as conditions.
331    
332    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
333        assertion subpattern, including such a pattern used as a condition,
334        unpredictable results occurred, instead of the error return
335        PCRE_ERROR_DFA_UITEM.
336    
337    5.  The C++ GlobalReplace function was not working like Perl for the special
338        situation when an empty string is matched. It now does the fancy magic
339        stuff that is necessary.
340    
341    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
342        removed. (These were left over from very, very early versions of PCRE.)
343    
344    7.  Some cosmetic changes to the code to make life easier when compiling it
345        as part of something else:
346    
347        (a) Change DEBUG to PCRE_DEBUG.
348    
349        (b) In pcre_compile(), rename the member of the "branch_chain" structure
350            called "current" as "current_branch", to prevent a collision with the
351            Linux macro when compiled as a kernel module.
352    
353        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
354            prevent a collision with the Linux macro when compiled as a kernel
355            module.
356    
357    8.  In pcre_compile() there are some checks for integer overflows that used to
358        cast potentially large values to (double). This has been changed to that
359        when building, a check for int64_t is made, and if it is found, it is used
360        instead, thus avoiding the use of floating point arithmetic. (There is no
361        other use of FP in PCRE.) If int64_t is not found, the fallback is to
362        double.
363    
364    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
365        2005 (difference between two addresses compared to an unsigned value).
366    
367    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
368        custom one, because of the following reported problem in Windows:
369    
370          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
371              under Win32.
372          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
373              therefore missing the function definition.
374          - The compiler thus generates a "C" signature for the test function.
375          - The linker fails to find the "C" function.
376          - PCRE fails to configure if asked to do so against libbz2.
377    
378    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
379        messages were output:
380    
381          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
382          rerunning libtoolize, to keep the correct libtool macros in-tree.
383          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
384    
385        I have done both of these things.
386    
387    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
388        most of the time, it *can* run out if it is given a pattern that contains a
389        runaway infinite recursion. I updated the discussion in the pcrestack man
390        page.
391    
392    13. Now that we have gone to the x.xx style of version numbers, the minor
393        version may start with zero. Using 08 or 09 is a bad idea because users
394        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
395        interpreted as invalid octal numbers. I've updated the previous comment in
396        configure.ac, and also added a check that gives an error if 08 or 09 are
397        used.
398    
399    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
400        causing partial matching to fail when the end of the subject matched \W
401        in a UTF-8 pattern where \W was quantified with a minimum of 3.
402    
403    15. There were some discrepancies between the declarations in pcre_internal.h
404        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
405        their definitions. The declarations used "const uschar *" and the
406        definitions used USPTR. Even though USPTR is normally defined as "const
407        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
408        reported that: "This difference in casting confuses some C++ compilers, for
409        example, SunCC recognizes above declarations as different functions and
410        generates broken code for hbpcre." I have changed the declarations to use
411        USPTR.
412    
413    16. GNU libtool is named differently on some systems. The autogen.sh script now
414        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
415        (FreeBSD).
416    
417    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
418        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
419        comment: "Figure out how to create a longlong from a string: strtoll and
420        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
421        instance, but it only takes 2 args instead of 3!"
422    
423    18. A subtle bug concerned with back references has been fixed by a change of
424        specification, with a corresponding code fix. A pattern such as
425        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
426        refers, was giving matches when it shouldn't. For example, xa=xaaa would
427        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
428        same bug. Such groups have to be quantified to be useful, or contained
429        inside another quantified group. (If there's no repetition, the reference
430        can never match.) The problem arises because, having left the group and
431        moved on to the rest of the pattern, a later failure that backtracks into
432        the group uses the captured value from the final iteration of the group
433        rather than the correct earlier one. I have fixed this in PCRE by forcing
434        any group that contains a reference to itself to be an atomic group; that
435        is, there cannot be any backtracking into it once it has completed. This is
436        similar to recursive and subroutine calls.
437    
438    
439    Version 8.00 19-Oct-09
440    ----------------------
441    
442    1.  The table for translating pcre_compile() error codes into POSIX error codes
443        was out-of-date, and there was no check on the pcre_compile() error code
444        being within the table. This could lead to an OK return being given in
445        error.
446    
447    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
448        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
449        in a Windows environment.
450    
451    3.  The pcregrep --count option prints the count for each file even when it is
452        zero, as does GNU grep. However, pcregrep was also printing all files when
453        --files-with-matches was added. Now, when both options are given, it prints
454        counts only for those files that have at least one match. (GNU grep just
455        prints the file name in this circumstance, but including the count seems
456        more useful - otherwise, why use --count?) Also ensured that the
457        combination -clh just lists non-zero counts, with no names.
458    
459    4.  The long form of the pcregrep -F option was incorrectly implemented as
460        --fixed_strings instead of --fixed-strings. This is an incompatible change,
461        but it seems right to fix it, and I didn't think it was worth preserving
462        the old behaviour.
463    
464    5.  The command line items --regex=pattern and --regexp=pattern were not
465        recognized by pcregrep, which required --regex pattern or --regexp pattern
466        (with a space rather than an '='). The man page documented the '=' forms,
467        which are compatible with GNU grep; these now work.
468    
469    6.  No libpcreposix.pc file was created for pkg-config; there was just
470        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
471    
472    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
473        when UCP support is not needed, by modifying the Python script that
474        generates it from Unicode data files. This should not matter if the module
475        is correctly used as a library, but I received one complaint about 50K of
476        unwanted data. My guess is that the person linked everything into his
477        program rather than using a library. Anyway, it does no harm.
478    
479    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
480        was a minimum greater than 1 for a wide character in a possessive
481        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
482        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
483        character. Chaos in the form of incorrect output or a compiling loop could
484        result.
485    
486    9.  The restrictions on what a pattern can contain when partial matching is
487        requested for pcre_exec() have been removed. All patterns can now be
488        partially matched by this function. In addition, if there are at least two
489        slots in the offset vector, the offset of the earliest inspected character
490        for the match and the offset of the end of the subject are set in them when
491        PCRE_ERROR_PARTIAL is returned.
492    
493    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
494        synonymous with PCRE_PARTIAL, for backwards compatibility, and
495        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
496        and may be more useful for multi-segment matching.
497    
498    11. Partial matching with pcre_exec() is now more intuitive. A partial match
499        used to be given if ever the end of the subject was reached; now it is
500        given only if matching could not proceed because another character was
501        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
502        string "Z", which now yields "no match" instead of "partial match". In the
503        case of pcre_dfa_exec(), "no match" is given if every matching path for the
504        final character ended with (*FAIL).
505    
506    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
507        if the pattern had a "must contain" character that was already found in the
508        earlier partial match, unless partial matching was again requested. For
509        example, with the pattern /dog.(body)?/, the "must contain" character is
510        "g". If the first part-match was for the string "dog", restarting with
511        "sbody" failed. This bug has been fixed.
512    
513    13. The string returned by pcre_dfa_exec() after a partial match has been
514        changed so that it starts at the first inspected character rather than the
515        first character of the match. This makes a difference only if the pattern
516        starts with a lookbehind assertion or \b or \B (\K is not supported by
517        pcre_dfa_exec()). It's an incompatible change, but it makes the two
518        matching functions compatible, and I think it's the right thing to do.
519    
520    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
521        so that the demonstration program is easily available in environments where
522        PCRE has not been installed from source.
523    
524    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
525        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
526        library.
527    
528    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
529        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
530        is not the first non-POSIX option to be added. Clearly some people find
531        these options useful.
532    
533    17. If a caller to the POSIX matching function regexec() passes a non-zero
534        value for nmatch with a NULL value for pmatch, the value of
535        nmatch is forced to zero.
536    
537    18. RunGrepTest did not have a test for the availability of the -u option of
538        the diff command, as RunTest does. It now checks in the same way as
539        RunTest, and also checks for the -b option.
540    
541    19. If an odd number of negated classes containing just a single character
542        interposed, within parentheses, between a forward reference to a named
543        subpattern and the definition of the subpattern, compilation crashed with
544        an internal error, complaining that it could not find the referenced
545        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
546        [The bug was that it was starting one character too far in when skipping
547        over the character class, thus treating the ] as data rather than
548        terminating the class. This meant it could skip too much.]
549    
550    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
551        /g option in pcretest when the pattern contains \K, which makes it possible
552        to have an empty string match not at the start, even when the pattern is
553        anchored. Updated pcretest and pcredemo to use this option.
554    
555    21. If the maximum number of capturing subpatterns in a recursion was greater
556        than the maximum at the outer level, the higher number was returned, but
557        with unset values at the outer level. The correct (outer level) value is
558        now given.
559    
560    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
561        PCRE did not set those parentheses (unlike Perl). I have now found a way to
562        make it do so. The string so far is captured, making this feature
563        compatible with Perl.
564    
565    23. The tests have been re-organized, adding tests 11 and 12, to make it
566        possible to check the Perl 5.10 features against Perl 5.10.
567    
568    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
569        pattern matches a fixed length string. PCRE did not allow this; now it
570        does. Neither allows recursion.
571    
572    25. I finally figured out how to implement a request to provide the minimum
573        length of subject string that was needed in order to match a given pattern.
574        (It was back references and recursion that I had previously got hung up
575        on.) This code has now been added to pcre_study(); it finds a lower bound
576        to the length of subject needed. It is not necessarily the greatest lower
577        bound, but using it to avoid searching strings that are too short does give
578        some useful speed-ups. The value is available to calling programs via
579        pcre_fullinfo().
580    
581    26. While implementing 25, I discovered to my embarrassment that pcretest had
582        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
583        study optimizations had never been tested with that matching function.
584        Oops. What is worse, even when it was passed study data, there was a bug in
585        pcre_dfa_exec() that meant it never actually used it. Double oops. There
586        were also very few tests of studied patterns with pcre_dfa_exec().
587    
588    27. If (?| is used to create subpatterns with duplicate numbers, they are now
589        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
590        on the other side of the coin, they are no longer allowed to have different
591        names, because these cannot be distinguished in PCRE, and this has caused
592        confusion. (This is a difference from Perl.)
593    
594    28. When duplicate subpattern names are present (necessarily with different
595        numbers, as required by 27 above), and a test is made by name in a
596        conditional pattern, either for a subpattern having been matched, or for
597        recursion in such a pattern, all the associated numbered subpatterns are
598        tested, and the overall condition is true if the condition is true for any
599        one of them. This is the way Perl works, and is also more like the way
600        testing by number works.
601    
602    
603    Version 7.9 11-Apr-09
604    ---------------------
605    
606    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
607        (pcretest), all targets were linked against these libraries. This included
608        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
609        libraries. This caused unwanted dependencies to be created. This problem
610        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
611        pcretest is linked with readline.
612    
613    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
614        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
615        moved outside it again, because FALSE and TRUE are already defined in AIX,
616        but BOOL is not.
617    
618    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
619        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
620    
621    4.  The pcregrep documentation said spaces were inserted as well as colons (or
622        hyphens) following file names and line numbers when outputting matching
623        lines. This is not true; no spaces are inserted. I have also clarified the
624        wording for the --colour (or --color) option.
625    
626    5.  In pcregrep, when --colour was used with -o, the list of matching strings
627        was not coloured; this is different to GNU grep, so I have changed it to be
628        the same.
629    
630    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
631        each matching line was coloured. Now it goes on to look for further matches
632        of any of the test patterns, which is the same behaviour as GNU grep.
633    
634    7.  A pattern that could match an empty string could cause pcregrep to loop; it
635        doesn't make sense to accept an empty string match in pcregrep, so I have
636        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
637        seems to be how GNU grep behaves.
638    
639    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
640        start or after a newline", because the conditional assertion was not being
641        correctly handled. The rule now is that both the assertion and what follows
642        in the first alternative must satisfy the test.
643    
644    9.  If auto-callout was enabled in a pattern with a conditional group whose
645        condition was an assertion, PCRE could crash during matching, both with
646        pcre_exec() and pcre_dfa_exec().
647    
648    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
649        used for matching.
650    
651    11. Unicode property support in character classes was not working for
652        characters (bytes) greater than 127 when not in UTF-8 mode.
653    
654    12. Added the -M command line option to pcretest.
655    
656    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
657    
658    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
659    
660    16. Added comments and documentation about mis-use of no_arg in the C++
661        wrapper.
662    
663    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
664        from Martin Jerabek that uses macro names for all relevant character and
665        string constants.
666    
667    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
668        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
669        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
670        these, but not everybody uses configure.
671    
672    19. A conditional group that had only one branch was not being correctly
673        recognized as an item that could match an empty string. This meant that an
674        enclosing group might also not be so recognized, causing infinite looping
675        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
676        with the subject "ab", where knowledge that the repeated group can match
677        nothing is needed in order to break the loop.
678    
679    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
680        exec(), but without supplying a callout function, matching went wrong.
681    
682    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
683        leak if the size of the offset vector was greater than 30. When the vector
684        is smaller, the saved offsets during recursion go onto a local stack
685        vector, but for larger vectors malloc() is used. It was failing to free
686        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
687        error, in fact).
688    
689    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
690        heapframe that is used only when UTF-8 support is enabled. This caused no
691        problem, but was untidy.
692    
693    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
694        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
695        included within another project.
696    
697    24. Steven Van Ingelgem's patches to add more options to the CMake support,
698        slightly modified by me:
699    
700          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
701              not building pcregrep.
702    
703          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
704              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
705    
706    25. Forward references, both numeric and by name, in patterns that made use of
707        duplicate group numbers, could behave incorrectly or give incorrect errors,
708        because when scanning forward to find the reference group, PCRE was not
709        taking into account the duplicate group numbers. A pattern such as
710        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
711    
712    26. Changed a few more instances of "const unsigned char *" to USPTR, making
713        the feature of a custom pointer more persuasive (as requested by a user).
714    
715    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
716        pcretest.c, inside #ifndefs, because it seems they are sometimes already
717        pre-defined.
718    
719    28. Added support for (*UTF8) at the start of a pattern.
720    
721    29. Arrange for flags added by the "release type" setting in CMake to be shown
722        in the configuration summary.
723    
724    
725    Version 7.8 05-Sep-08
726    ---------------------
727    
728    1.  Replaced UCP searching code with optimized version as implemented for Ad
729        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
730        stage table and inline lookup instead of a function, giving speed ups of 2
731        to 5 times on some simple patterns that I tested. Permission was given to
732        distribute the MultiStage2.py script that generates the tables (it's not in
733        the tarball, but is in the Subversion repository).
734    
735    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
736        scripts.
737    
738    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
739        a group with a zero qualifier. The result of the study could be incorrect,
740        or the function might crash, depending on the pattern.
741    
742    4.  Caseless matching was not working for non-ASCII characters in back
743        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
744        It now works when Unicode Property Support is available.
745    
746    5.  In pcretest, an escape such as \x{de} in the data was always generating
747        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
748        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
749        truncation.
750    
751    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
752    
753    7.  Added two (int) casts to pcregrep when printing the difference of two
754        pointers, in case they are 64-bit values.
755    
756    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
757        test 2 if it fails.
758    
759    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
760        and a #define of that name to empty if it is not externally set. This is to
761        allow users of MSVC to set it if necessary.
762    
763    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
764        the convenience functions in the pcre_get.c source file.
765    
766    11. An option change at the start of a pattern that had top-level alternatives
767        could cause overwriting and/or a crash. This command provoked a crash in
768        some environments:
769    
770          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
771    
772        This potential security problem was recorded as CVE-2008-2371.
773    
774    12. For a pattern where the match had to start at the beginning or immediately
775        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
776        pcre_dfa_exec() could read past the end of the passed subject if there was
777        no match. To help with detecting such bugs (e.g. with valgrind), I modified
778        pcretest so that it places the subject at the end of its malloc-ed buffer.
779    
780    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
781        exec() might read past the end of the data buffer in UTF-8 mode.
782    
783    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
784        the data contained the byte 0x85 as part of a UTF-8 character within its
785        first line. This applied both to normal and DFA matching.
786    
787    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
788        /^[^d]*?$/8 failed to match "abc".
789    
790    16. Added a missing copyright notice to pcrecpp_internal.h.
791    
792    17. Make it more clear in the documentation that values returned from
793        pcre_exec() in ovector are byte offsets, not character counts.
794    
795    18. Tidied a few places to stop certain compilers from issuing warnings.
796    
797    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
798        supplied by Stefan Weber. I made a further small update for 7.8 because
799        there is a change of source arrangements: the pcre_searchfuncs.c module is
800        replaced by pcre_ucd.c.
801    
802    
803    Version 7.7 07-May-08
804    ---------------------
805    
806    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
807        a string to a long long, pretend we don't even have a long long." This is
808        done by checking for the strtoq, strtoll, and _strtoi64 functions.
809    
810    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
811        pre-7.6 versions, which defined a global no_arg variable instead of putting
812        it in the RE class. (See also #8 below.)
813    
814    3.  Remove a line of dead code, identified by coverity and reported by Nuno
815        Lopes.
816    
817    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
818    
819        (1) The include/exclude patterns were being applied to the whole pathnames
820            of files, instead of just to the final components.
821    
822        (2) If there was more than one level of directory, the subdirectories were
823            skipped unless they satisfied the include/exclude conditions. This is
824            inconsistent with GNU grep (and could even be seen as contrary to the
825            pcregrep specification - which I improved to make it absolutely clear).
826            The action now is always to scan all levels of directory, and just
827            apply the include/exclude patterns to regular files.
828    
829    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
830        --exclude_dir in the tests to avoid scanning .svn directories.
831    
832    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
833        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
834        doesn't support NULs in patterns.
835    
836    7.  Added some missing "const"s to declarations of static tables in
837        pcre_compile.c and pcre_dfa_exec.c.
838    
839    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
840        caused by fix #2  above. (Subsequently also a second patch to fix the
841        first patch. And a third patch - this was a messy problem.)
842    
843    9.  Applied Craig's patch to remove the use of push_back().
844    
845    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
846        matching function regexec().
847    
848    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
849        which, however, unlike Perl's \g{...}, are subroutine calls, not back
850        references. PCRE supports relative numbers with this syntax (I don't think
851        Oniguruma does).
852    
853    12. Previously, a group with a zero repeat such as (...){0} was completely
854        omitted from the compiled regex. However, this means that if the group
855        was called as a subroutine from elsewhere in the pattern, things went wrong
856        (an internal error was given). Such groups are now left in the compiled
857        pattern, with a new opcode that causes them to be skipped at execution
858        time.
859    
860    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
861        to the way PCRE behaves:
862    
863        (a) A lone ] character is dis-allowed (Perl treats it as data).
864    
865        (b) A back reference to an unmatched subpattern matches an empty string
866            (Perl fails the current match path).
867    
868        (c) A data ] in a character class must be notated as \] because if the
869            first data character in a class is ], it defines an empty class. (In
870            Perl it is not possible to have an empty class.) The empty class []
871            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
872            The negative empty class [^] matches any one character, independently
873            of the DOTALL setting.
874    
875    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
876        non-existent subpattern following a character class starting with ']' and
877        containing () gave an internal compiling error instead of "reference to
878        non-existent subpattern". Fortunately, when the pattern did exist, the
879        compiled code was correct. (When scanning forwards to check for the
880        existencd of the subpattern, it was treating the data ']' as terminating
881        the class, so got the count wrong. When actually compiling, the reference
882        was subsequently set up correctly.)
883    
884    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
885        it was being rejected as not supported by pcre_dfa_exec(), even though
886        other assertions are supported. I have made pcre_dfa_exec() support
887        (*FAIL).
888    
889    16. The implementation of 13c above involved the invention of a new opcode,
890        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
891        cannot be changed at match time, I realized I could make a small
892        improvement to matching performance by compiling OP_ALLANY instead of
893        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
894        on the OP_ANY path.
895    
896    17. Compiling pcretest on Windows with readline support failed without the
897        following two fixes: (1) Make the unistd.h include conditional on
898        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
899    
900    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
901        ncurses library to be included for pcretest when ReadLine support is
902        requested, but also to allow for it to be overridden. This patch came from
903        Daniel Bergström.
904    
905    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
906        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
907        any errors with the current Unicode tables. Thanks to Peter Kankowski for
908        spotting this.
909    
910    
911    Version 7.6 28-Jan-08
912  ---------------------  ---------------------
913    
914  1.  A character class containing a very large number of characters with  1.  A character class containing a very large number of characters with
# Line 16  Version 7.6 21-Jan-08 Line 923  Version 7.6 21-Jan-08
923    
924      - Fixed PH's badly added libz and libbz2 support.      - Fixed PH's badly added libz and libbz2 support.
925      - Fixed a problem with static linking.      - Fixed a problem with static linking.
926      - Added pcredemo.      - Added pcredemo. [But later removed - see 7 below.]
927      - Fixed dftables problem and added an option.      - Fixed dftables problem and added an option.
928      - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and      - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
929          HAVE_LONG_LONG.          HAVE_LONG_LONG.
930      - Added readline support for pcretest.      - Added readline support for pcretest.
931      - Added an listing of the option settings after cmake has run.      - Added an listing of the option settings after cmake has run.
932    
933  4.  A user submitted a patch to Makefile that makes it easy to created a dll  4.  A user submitted a patch to Makefile that makes it easy to create
934      under mingw. I added stuff to Makefile.am that cause it to include this      "pcre.dll" under mingw when using Configure/Make. I added stuff to
935      special target, without affecting anything else.      Makefile.am that cause it to include this special target, without
936        affecting anything else. Note that the same mingw target plus all
937        the other distribution libraries and programs are now supported
938        when configuring with CMake (see 6 below) instead of with
939        Configure/Make.
940    
941  5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.  5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
942      This is an attempt to solve the reported problem "pcrecpp::no_arg is not      This is an attempt to solve the reported problem "pcrecpp::no_arg is not
943      exported in the Windows port". It has not yet been confirmed that the patch      exported in the Windows port". It has not yet been confirmed that the patch
944      solves the problem, but it does no harm.      solves the problem, but it does no harm.
945    
946    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
947        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
948        with CMake, and also correct the comment about stack recursion.
949    
950    7.  Remove the automatic building of pcredemo from the ./configure system and
951        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
952        of a program that users should build themselves after PCRE is installed, so
953        building it automatically is not really right. What is more, it gave
954        trouble in some build environments.
955    
956    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
957    
958    
959  Version 7.5 10-Jan-08  Version 7.5 10-Jan-08
960  ---------------------  ---------------------

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