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revision 513 by ph10, Mon May 3 11:13:37 2010 UTC revision 609 by ph10, Wed Jun 15 18:09:23 2011 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.10 03 May-2010  Version 8.13 30-Apr-2011
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
9    2.  Two minor typos in pcre_internal.h have been fixed.
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).
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).
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.
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().
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.
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.
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.
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().
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
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.
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.
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.
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.
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.
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.
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.
102    Version 8.12 15-Jan-2011
103    ------------------------
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.
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.)
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.
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.
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.
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).
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.
136    Version 8.11 10-Dec-2010
137    ------------------------
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".
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).
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.)
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").
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.]
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().
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.
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.
192    9.  Added --match-limit and --recursion-limit to pcregrep.
194    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
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.
199    12. Added an optional parentheses number to the -o and --only-matching options
200        of pcregrep.
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:
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).
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.)
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.
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.
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.
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.
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.
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).
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.)
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().
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.
262    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
263        pcretest.c, to avoid build problems in some Borland environments.
266    Version 8.10 25-Jun-2010
267  ------------------------  ------------------------
269  1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and  1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
# Line 9  Version 8.10 03 May-2010 Line 271  Version 8.10 03 May-2010
272  2.  (*ACCEPT) was not working when inside an atomic group.  2.  (*ACCEPT) was not working when inside an atomic group.
274  3.  Inside a character class, \B is treated as a literal by default, but  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      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.      causes the error). The code is unchanged, but I tidied the documentation.
278  4.  Inside a character class, PCRE always treated \R and \X as literals,  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      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.      that it faults them when PCRE_EXTRA is set.
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.)
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.
291    7.  Minor change to pcretest.c to avoid a compiler warning.
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).
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.
302    10. Added --line-buffered to pcregrep.
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).
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).
316    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
317        possible starting bytes for non-anchored patterns.
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.
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.)
328    16. Added a lot of (int) casts to avoid compiler warnings in systems where
329        size_t is 64-bit (#991).
331    17. Added a check for running out of memory when PCRE is compiled with
332        --disable-stack-for-recursion (#990).
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.
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.)
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.
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.
361  Version 8.02 19-Mar-2010  Version 8.02 19-Mar-2010
362  ------------------------  ------------------------

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