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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.9 xx-xxx-09  Version 8.13 30-Apr-2011
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
8    
9    2.  Two minor typos in pcre_internal.h have been fixed.
10    
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
14    
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
23    
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
28    
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
34    
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
38    
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
46    
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55    
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
59    
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
62    
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
68    
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
72    
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
77    
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collection of tests with study enabled,
83        and thereby test pcre_study() more easily.
84    
85    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
86        restoration of the capturing data to the outer values was not happening
87        correctly.
88    
89    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
90        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
91        pattern had matched an empty string, and so incorrectly returned a no
92        match.
93    
94    17. There was optimizing code for the last branch of non-capturing parentheses,
95        and also for the obeyed branch of a conditional subexpression, which used
96        tail recursion to cut down on stack usage. Unfortunately, not that there is
97        the possibility of (*THEN) occurring in these branches, tail recursion is
98        no longer possible because the return has to be checked for (*THEN). These
99        two optimizations have therefore been removed.
100    
101    
102    Version 8.12 15-Jan-2011
103    ------------------------
104    
105    1.  Fixed some typos in the markup of the man pages, and wrote a script that
106        checks for such things as part of the documentation building process.
107    
108    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
109        --match-limit and --recursion-limit options (added for 8.11). In
110        particular, this made one of the standard tests fail. (The integer value
111        went into the wrong half of a long int.)
112    
113    3.  If the --colour option was given to pcregrep with -v (invert match), it
114        did strange things, either producing crazy output, or crashing. It should,
115        of course, ignore a request for colour when reporting lines that do not
116        match.
117    
118    4.  Another pcregrep bug caused similar problems if --colour was specified with
119        -M (multiline) and the pattern match finished with a line ending.
120    
121    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
122        matched in multiline mode, the following line was shown as part of the
123        match. This seems wrong, so I have changed it.
124    
125    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
126        the check for further matches in the same line (so they could be coloured)
127        to overrun the end of the current line. If another match was found, it was
128        incorrectly shown (and then shown again when found in the next line).
129    
130    7.  If pcregrep was compiled under Windows, there was a reference to the
131        function pcregrep_exit() before it was defined. I am assuming this was
132        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
133        reported by a user. I've moved the definition above the reference.
134    
135    
136    Version 8.11 10-Dec-2010
137    ------------------------
138    
139    1.  (*THEN) was not working properly if there were untried alternatives prior
140        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
141        backtracked to try for "b" instead of moving to the next alternative branch
142        at the same level (in this case, to look for "c"). The Perl documentation
143        is clear that when (*THEN) is backtracked onto, it goes to the "next
144        alternative in the innermost enclosing group".
145    
146    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
147        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
148        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
149        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
150        (*THEN).
151    
152    3.  If \s appeared in a character class, it removed the VT character from
153        the class, even if it had been included by some previous item, for example
154        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
155        of \s, but is part of the POSIX "space" class.)
156    
157    4.  A partial match never returns an empty string (because you can always
158        match an empty string at the end of the subject); however the checking for
159        an empty string was starting at the "start of match" point. This has been
160        changed to the "earliest inspected character" point, because the returned
161        data for a partial match starts at this character. This means that, for
162        example, /(?<=abc)def/ gives a partial match for the subject "abc"
163        (previously it gave "no match").
164    
165    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
166        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
167        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
168        has an implication that the given string is incomplete (because a partial
169        match is preferred over a full match). For this reason, these items now
170        give a partial match in this situation. [Aside: previously, the one case
171        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
172        match rather than a full match, which was wrong by the old rules, but is
173        now correct.]
174    
175    6.  There was a bug in the handling of #-introduced comments, recognized when
176        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
177        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
178        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
179        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
180        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
181        places in pcre_compile().
182    
183    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
184        comments when looking ahead for named forward references to subpatterns,
185        the only newline sequence it recognized was NL. It now handles newlines
186        according to the set newline convention.
187    
188    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
189        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
190        cater for a lack of strerror(). These oversights have been fixed.
191    
192    9.  Added --match-limit and --recursion-limit to pcregrep.
193    
194    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
195    
196    11. When the -o option was used, pcregrep was setting a return code of 1, even
197        when matches were found, and --line-buffered was not being honoured.
198    
199    12. Added an optional parentheses number to the -o and --only-matching options
200        of pcregrep.
201    
202    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
203        can match an empty string. The code to do it in pcretest and pcredemo
204        needed fixing:
205    
206        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
207            only one byte after an empty string match just before CRLF (this case
208            just got forgotten; "any" and "anycrlf" were OK).
209    
210        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
211            mode when an empty string match preceded an ASCII character followed by
212            a non-ASCII character. (The code for advancing by one character rather
213            than one byte was nonsense.)
214    
215        (c) The pcredemo.c sample program did not have any code at all to handle
216            the cases when CRLF is a valid newline sequence.
217    
218    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
219        as a starting offset was within the subject string. There is now a new
220        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
221        negative or greater than the length of the string. In order to test this,
222        pcretest is extended to allow the setting of negative starting offsets.
223    
224    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
225        starting offset points to the beginning of a UTF-8 character was
226        unnecessarily clumsy. I tidied it up.
227    
228    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
229        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
230    
231    17. Nobody had reported that the --include_dir option, which was added in
232        release 7.7 should have been called --include-dir (hyphen, not underscore)
233        for compatibility with GNU grep. I have changed it to --include-dir, but
234        left --include_dir as an undocumented synonym, and the same for
235        --exclude-dir, though that is not available in GNU grep, at least as of
236        release 2.5.4.
237    
238    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
239        characters from a string of bytes) have been redefined so as not to use
240        loops, in order to improve performance in some environments. At the same
241        time, I abstracted some of the common code into auxiliary macros to save
242        repetition (this should not affect the compiled code).
243    
244    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
245        compile-time error is now given if \c is not followed by an ASCII
246        character, that is, a byte less than 128. (In EBCDIC mode, the code is
247        different, and any byte value is allowed.)
248    
249    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
250        START_OPTIMIZE option, which is now allowed at compile time - but just
251        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
252        to pcregrep and other applications that have no direct access to PCRE
253        options. The new /Y option in pcretest sets this option when calling
254        pcre_compile().
255    
256    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
257        back references. Groups containing recursive back references were forced to
258        be atomic by that change, but in the case of named groups, the amount of
259        memory required was incorrectly computed, leading to "Failed: internal
260        error: code overflow". This has been fixed.
261    
262    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
263        pcretest.c, to avoid build problems in some Borland environments.
264    
265    
266    Version 8.10 25-Jun-2010
267    ------------------------
268    
269    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
270        THEN.
271    
272    2.  (*ACCEPT) was not working when inside an atomic group.
273    
274    3.  Inside a character class, \B is treated as a literal by default, but
275        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
276        causes the error). The code is unchanged, but I tidied the documentation.
277    
278    4.  Inside a character class, PCRE always treated \R and \X as literals,
279        whereas Perl faults them if its -w option is set. I have changed PCRE so
280        that it faults them when PCRE_EXTRA is set.
281    
282    5.  Added support for \N, which always matches any character other than
283        newline. (It is the same as "." when PCRE_DOTALL is not set.)
284    
285    6.  When compiling pcregrep with newer versions of gcc which may have
286        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
287        declared with attribute warn_unused_result" were given. Just casting the
288        result to (void) does not stop the warnings; a more elaborate fudge is
289        needed. I've used a macro to implement this.
290    
291    7.  Minor change to pcretest.c to avoid a compiler warning.
292    
293    8.  Added four artifical Unicode properties to help with an option to make
294        \s etc use properties (see next item). The new properties are: Xan
295        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
296    
297    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
298        use Unicode properties. (*UCP) at the start of a pattern can be used to set
299        this option. Modified pcretest to add /W to test this facility. Added
300        REG_UCP to make it available via the POSIX interface.
301    
302    10. Added --line-buffered to pcregrep.
303    
304    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
305        studied, and the match started with a letter with a code point greater than
306        127 whose first byte was different to the first byte of the other case of
307        the letter, the other case of this starting letter was not recognized
308        (#976).
309    
310    12. If a pattern that was studied started with a repeated Unicode property
311        test, for example, \p{Nd}+, there was the theoretical possibility of
312        setting up an incorrect bitmap of starting bytes, but fortunately it could
313        not have actually happened in practice until change 8 above was made (it
314        added property types that matched character-matching opcodes).
315    
316    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
317        possible starting bytes for non-anchored patterns.
318    
319    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
320        \R, and also a number of cases that involve Unicode properties, both
321        explicit and implicit when PCRE_UCP is set.
322    
323    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
324        input, it could crash or give wrong results if characters with values
325        greater than 0xc0 were present in the subject string. (Detail: it assumed
326        UTF-8 input when processing these items.)
327    
328    16. Added a lot of (int) casts to avoid compiler warnings in systems where
329        size_t is 64-bit (#991).
330    
331    17. Added a check for running out of memory when PCRE is compiled with
332        --disable-stack-for-recursion (#990).
333    
334    18. If the last data line in a file for pcretest does not have a newline on
335        the end, a newline was missing in the output.
336    
337    19. The default pcre_chartables.c file recognizes only ASCII characters (values
338        less than 128) in its various bitmaps. However, there is a facility for
339        generating tables according to the current locale when PCRE is compiled. It
340        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
341        characters, are recognized by isspace() and therefore were getting set in
342        these tables, and indeed these tables seem to approximate to ISO 8859. This
343        caused a problem in UTF-8 mode when pcre_study() was used to create a list
344        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
345        which of course cannot start UTF-8 characters. I have changed the code so
346        that only real ASCII characters (less than 128) and the correct starting
347        bytes for UTF-8 encodings are set for characters greater than 127 when in
348        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
349        altogether.)
350    
351    20. Added the /T option to pcretest so as to be able to run tests with non-
352        standard character tables, thus making it possible to include the tests
353        used for 19 above in the standard set of tests.
354    
355    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
356        reference to a subpattern the other side of a comment that contains an
357        opening parenthesis caused either an internal compiling error, or a
358        reference to the wrong subpattern.
359    
360    
361    Version 8.02 19-Mar-2010
362    ------------------------
363    
364    1.  The Unicode data tables have been updated to Unicode 5.2.0.
365    
366    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
367        configured.
368    
369    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
370        original author of that file, following a query about its status.
371    
372    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
373        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
374    
375    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
376        quantifier applied to a forward-referencing subroutine call, could compile
377        incorrect code or give the error "internal error: previously-checked
378        referenced subpattern not found".
379    
380    6.  Both MS Visual Studio and Symbian OS have problems with initializing
381        variables to point to external functions. For these systems, therefore,
382        pcre_malloc etc. are now initialized to local functions that call the
383        relevant global functions.
384    
385    7.  There were two entries missing in the vectors called coptable and poptable
386        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
387        I've fixed the data, and added a kludgy way of testing at compile time that
388        the lengths are correct (equal to the number of opcodes).
389    
390    8.  Following on from 7, I added a similar kludge to check the length of the
391        eint vector in pcreposix.c.
392    
393    9.  Error texts for pcre_compile() are held as one long string to avoid too
394        much relocation at load time. To find a text, the string is searched,
395        counting zeros. There was no check for running off the end of the string,
396        which could happen if a new error number was added without updating the
397        string.
398    
399    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
400    
401    11. \K was not working if it appeared in an atomic group or in a group that
402        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
403        \K is "not well defined" if used in an assertion. PCRE now accepts it if
404        the assertion is positive, but not if it is negative.
405    
406    12. Change 11 fortuitously reduced the size of the stack frame used in the
407        "match()" function of pcre_exec.c by one pointer. Forthcoming
408        implementation of support for (*MARK) will need an extra pointer on the
409        stack; I have reserved it now, so that the stack frame size does not
410        decrease.
411    
412    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
413        item in branch that calls a recursion is a subroutine call - as in the
414        second branch in the above example - was incorrectly given the compile-
415        time error "recursive call could loop indefinitely" because pcre_compile()
416        was not correctly checking the subroutine for matching a non-empty string.
417    
418    14. The checks for overrunning compiling workspace could trigger after an
419        overrun had occurred. This is a "should never occur" error, but it can be
420        triggered by pathological patterns such as hundreds of nested parentheses.
421        The checks now trigger 100 bytes before the end of the workspace.
422    
423    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
424    
425    
426    Version 8.01 19-Jan-2010
427    ------------------------
428    
429    1.  If a pattern contained a conditional subpattern with only one branch (in
430        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
431        computed the wrong minimum data length (which is of course zero for such
432        subpatterns). This could cause incorrect "no match" results.
433    
434    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
435        the pattern is reset in the first branch, pcre_compile() failed with
436        "internal error: code overflow at offset...". This happened only when
437        the reset was to the original external option setting. (An optimization
438        abstracts leading options settings into an external setting, which was the
439        cause of this.)
440    
441    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
442        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
443        assertion pattern did not match (meaning that the assertion was true), it
444        was incorrectly treated as false if the SKIP had been reached during the
445        matching. This also applied to assertions used as conditions.
446    
447    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
448        assertion subpattern, including such a pattern used as a condition,
449        unpredictable results occurred, instead of the error return
450        PCRE_ERROR_DFA_UITEM.
451    
452    5.  The C++ GlobalReplace function was not working like Perl for the special
453        situation when an empty string is matched. It now does the fancy magic
454        stuff that is necessary.
455    
456    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
457        removed. (These were left over from very, very early versions of PCRE.)
458    
459    7.  Some cosmetic changes to the code to make life easier when compiling it
460        as part of something else:
461    
462        (a) Change DEBUG to PCRE_DEBUG.
463    
464        (b) In pcre_compile(), rename the member of the "branch_chain" structure
465            called "current" as "current_branch", to prevent a collision with the
466            Linux macro when compiled as a kernel module.
467    
468        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
469            prevent a collision with the Linux macro when compiled as a kernel
470            module.
471    
472    8.  In pcre_compile() there are some checks for integer overflows that used to
473        cast potentially large values to (double). This has been changed to that
474        when building, a check for int64_t is made, and if it is found, it is used
475        instead, thus avoiding the use of floating point arithmetic. (There is no
476        other use of FP in PCRE.) If int64_t is not found, the fallback is to
477        double.
478    
479    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
480        2005 (difference between two addresses compared to an unsigned value).
481    
482    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
483        custom one, because of the following reported problem in Windows:
484    
485          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
486              under Win32.
487          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
488              therefore missing the function definition.
489          - The compiler thus generates a "C" signature for the test function.
490          - The linker fails to find the "C" function.
491          - PCRE fails to configure if asked to do so against libbz2.
492    
493    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
494        messages were output:
495    
496          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
497          rerunning libtoolize, to keep the correct libtool macros in-tree.
498          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
499    
500        I have done both of these things.
501    
502    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
503        most of the time, it *can* run out if it is given a pattern that contains a
504        runaway infinite recursion. I updated the discussion in the pcrestack man
505        page.
506    
507    13. Now that we have gone to the x.xx style of version numbers, the minor
508        version may start with zero. Using 08 or 09 is a bad idea because users
509        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
510        interpreted as invalid octal numbers. I've updated the previous comment in
511        configure.ac, and also added a check that gives an error if 08 or 09 are
512        used.
513    
514    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
515        causing partial matching to fail when the end of the subject matched \W
516        in a UTF-8 pattern where \W was quantified with a minimum of 3.
517    
518    15. There were some discrepancies between the declarations in pcre_internal.h
519        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
520        their definitions. The declarations used "const uschar *" and the
521        definitions used USPTR. Even though USPTR is normally defined as "const
522        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
523        reported that: "This difference in casting confuses some C++ compilers, for
524        example, SunCC recognizes above declarations as different functions and
525        generates broken code for hbpcre." I have changed the declarations to use
526        USPTR.
527    
528    16. GNU libtool is named differently on some systems. The autogen.sh script now
529        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
530        (FreeBSD).
531    
532    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
533        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
534        comment: "Figure out how to create a longlong from a string: strtoll and
535        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
536        instance, but it only takes 2 args instead of 3!"
537    
538    18. A subtle bug concerned with back references has been fixed by a change of
539        specification, with a corresponding code fix. A pattern such as
540        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
541        refers, was giving matches when it shouldn't. For example, xa=xaaa would
542        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
543        same bug. Such groups have to be quantified to be useful, or contained
544        inside another quantified group. (If there's no repetition, the reference
545        can never match.) The problem arises because, having left the group and
546        moved on to the rest of the pattern, a later failure that backtracks into
547        the group uses the captured value from the final iteration of the group
548        rather than the correct earlier one. I have fixed this in PCRE by forcing
549        any group that contains a reference to itself to be an atomic group; that
550        is, there cannot be any backtracking into it once it has completed. This is
551        similar to recursive and subroutine calls.
552    
553    
554    Version 8.00 19-Oct-09
555    ----------------------
556    
557    1.  The table for translating pcre_compile() error codes into POSIX error codes
558        was out-of-date, and there was no check on the pcre_compile() error code
559        being within the table. This could lead to an OK return being given in
560        error.
561    
562    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
563        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
564        in a Windows environment.
565    
566    3.  The pcregrep --count option prints the count for each file even when it is
567        zero, as does GNU grep. However, pcregrep was also printing all files when
568        --files-with-matches was added. Now, when both options are given, it prints
569        counts only for those files that have at least one match. (GNU grep just
570        prints the file name in this circumstance, but including the count seems
571        more useful - otherwise, why use --count?) Also ensured that the
572        combination -clh just lists non-zero counts, with no names.
573    
574    4.  The long form of the pcregrep -F option was incorrectly implemented as
575        --fixed_strings instead of --fixed-strings. This is an incompatible change,
576        but it seems right to fix it, and I didn't think it was worth preserving
577        the old behaviour.
578    
579    5.  The command line items --regex=pattern and --regexp=pattern were not
580        recognized by pcregrep, which required --regex pattern or --regexp pattern
581        (with a space rather than an '='). The man page documented the '=' forms,
582        which are compatible with GNU grep; these now work.
583    
584    6.  No libpcreposix.pc file was created for pkg-config; there was just
585        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
586    
587    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
588        when UCP support is not needed, by modifying the Python script that
589        generates it from Unicode data files. This should not matter if the module
590        is correctly used as a library, but I received one complaint about 50K of
591        unwanted data. My guess is that the person linked everything into his
592        program rather than using a library. Anyway, it does no harm.
593    
594    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
595        was a minimum greater than 1 for a wide character in a possessive
596        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
597        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
598        character. Chaos in the form of incorrect output or a compiling loop could
599        result.
600    
601    9.  The restrictions on what a pattern can contain when partial matching is
602        requested for pcre_exec() have been removed. All patterns can now be
603        partially matched by this function. In addition, if there are at least two
604        slots in the offset vector, the offset of the earliest inspected character
605        for the match and the offset of the end of the subject are set in them when
606        PCRE_ERROR_PARTIAL is returned.
607    
608    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
609        synonymous with PCRE_PARTIAL, for backwards compatibility, and
610        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
611        and may be more useful for multi-segment matching.
612    
613    11. Partial matching with pcre_exec() is now more intuitive. A partial match
614        used to be given if ever the end of the subject was reached; now it is
615        given only if matching could not proceed because another character was
616        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
617        string "Z", which now yields "no match" instead of "partial match". In the
618        case of pcre_dfa_exec(), "no match" is given if every matching path for the
619        final character ended with (*FAIL).
620    
621    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
622        if the pattern had a "must contain" character that was already found in the
623        earlier partial match, unless partial matching was again requested. For
624        example, with the pattern /dog.(body)?/, the "must contain" character is
625        "g". If the first part-match was for the string "dog", restarting with
626        "sbody" failed. This bug has been fixed.
627    
628    13. The string returned by pcre_dfa_exec() after a partial match has been
629        changed so that it starts at the first inspected character rather than the
630        first character of the match. This makes a difference only if the pattern
631        starts with a lookbehind assertion or \b or \B (\K is not supported by
632        pcre_dfa_exec()). It's an incompatible change, but it makes the two
633        matching functions compatible, and I think it's the right thing to do.
634    
635    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
636        so that the demonstration program is easily available in environments where
637        PCRE has not been installed from source.
638    
639    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
640        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
641        library.
642    
643    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
644        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
645        is not the first non-POSIX option to be added. Clearly some people find
646        these options useful.
647    
648    17. If a caller to the POSIX matching function regexec() passes a non-zero
649        value for nmatch with a NULL value for pmatch, the value of
650        nmatch is forced to zero.
651    
652    18. RunGrepTest did not have a test for the availability of the -u option of
653        the diff command, as RunTest does. It now checks in the same way as
654        RunTest, and also checks for the -b option.
655    
656    19. If an odd number of negated classes containing just a single character
657        interposed, within parentheses, between a forward reference to a named
658        subpattern and the definition of the subpattern, compilation crashed with
659        an internal error, complaining that it could not find the referenced
660        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
661        [The bug was that it was starting one character too far in when skipping
662        over the character class, thus treating the ] as data rather than
663        terminating the class. This meant it could skip too much.]
664    
665    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
666        /g option in pcretest when the pattern contains \K, which makes it possible
667        to have an empty string match not at the start, even when the pattern is
668        anchored. Updated pcretest and pcredemo to use this option.
669    
670    21. If the maximum number of capturing subpatterns in a recursion was greater
671        than the maximum at the outer level, the higher number was returned, but
672        with unset values at the outer level. The correct (outer level) value is
673        now given.
674    
675    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
676        PCRE did not set those parentheses (unlike Perl). I have now found a way to
677        make it do so. The string so far is captured, making this feature
678        compatible with Perl.
679    
680    23. The tests have been re-organized, adding tests 11 and 12, to make it
681        possible to check the Perl 5.10 features against Perl 5.10.
682    
683    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
684        pattern matches a fixed length string. PCRE did not allow this; now it
685        does. Neither allows recursion.
686    
687    25. I finally figured out how to implement a request to provide the minimum
688        length of subject string that was needed in order to match a given pattern.
689        (It was back references and recursion that I had previously got hung up
690        on.) This code has now been added to pcre_study(); it finds a lower bound
691        to the length of subject needed. It is not necessarily the greatest lower
692        bound, but using it to avoid searching strings that are too short does give
693        some useful speed-ups. The value is available to calling programs via
694        pcre_fullinfo().
695    
696    26. While implementing 25, I discovered to my embarrassment that pcretest had
697        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
698        study optimizations had never been tested with that matching function.
699        Oops. What is worse, even when it was passed study data, there was a bug in
700        pcre_dfa_exec() that meant it never actually used it. Double oops. There
701        were also very few tests of studied patterns with pcre_dfa_exec().
702    
703    27. If (?| is used to create subpatterns with duplicate numbers, they are now
704        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
705        on the other side of the coin, they are no longer allowed to have different
706        names, because these cannot be distinguished in PCRE, and this has caused
707        confusion. (This is a difference from Perl.)
708    
709    28. When duplicate subpattern names are present (necessarily with different
710        numbers, as required by 27 above), and a test is made by name in a
711        conditional pattern, either for a subpattern having been matched, or for
712        recursion in such a pattern, all the associated numbered subpatterns are
713        tested, and the overall condition is true if the condition is true for any
714        one of them. This is the way Perl works, and is also more like the way
715        testing by number works.
716    
717    
718    Version 7.9 11-Apr-09
719  ---------------------  ---------------------
720    
721  1.  When building with support for bzlib/zlib (pcregrep) and/or readline  1.  When building with support for bzlib/zlib (pcregrep) and/or readline
# Line 17  Version 7.9 xx-xxx-09 Line 731  Version 7.9 xx-xxx-09
731      but BOOL is not.      but BOOL is not.
732    
733  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
734      PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.      PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
735    
736  4.  The pcregrep documentation said spaces were inserted as well as colons (or  4.  The pcregrep documentation said spaces were inserted as well as colons (or
737      hyphens) following file names and line numbers when outputting matching      hyphens) following file names and line numbers when outputting matching
# Line 94  Version 7.9 xx-xxx-09 Line 808  Version 7.9 xx-xxx-09
808  23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name  23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
809      CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is      CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
810      included within another project.      included within another project.
811    
812  24. Steven Van Ingelgem's patches to add more options to the CMake support,  24. Steven Van Ingelgem's patches to add more options to the CMake support,
813      slightly modified by me:      slightly modified by me:
814    
815        (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including        (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
816            not building pcregrep.            not building pcregrep.
817    
818        (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only        (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
819            if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.            if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
820    
821  25. Forward references, both numeric and by name, in patterns that made use of  25. Forward references, both numeric and by name, in patterns that made use of
822      duplicate group numbers, could behave incorrectly or give incorrect errors,      duplicate group numbers, could behave incorrectly or give incorrect errors,
823      because when scanning forward to find the reference group, PCRE was not      because when scanning forward to find the reference group, PCRE was not
824      taking into account the duplicate group numbers. A pattern such as      taking into account the duplicate group numbers. A pattern such as
825      ^X(?3)(a)(?|(b)|(q))(Y) is an example.      ^X(?3)(a)(?|(b)|(q))(Y) is an example.
826    
827    26. Changed a few more instances of "const unsigned char *" to USPTR, making
828        the feature of a custom pointer more persuasive (as requested by a user).
829    
830    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
831        pcretest.c, inside #ifndefs, because it seems they are sometimes already
832        pre-defined.
833    
834    28. Added support for (*UTF8) at the start of a pattern.
835    
836    29. Arrange for flags added by the "release type" setting in CMake to be shown
837        in the configuration summary.
838    
839    
840  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

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