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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.10 03-Jun-2010  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 collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
86    
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
90    
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
95    
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, not that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
102    
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
106    
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
109    
110    20. If /S is present twice on a test pattern in pcretest input, it *disables*
111        studying, thereby overriding the use of -s on the command line. This is
112        necessary for one or two tests to keep the output identical in both cases.
113    
114    21. When (*ACCEPT) was used in an assertion that matched an empty string and
115        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
116    
117    22. When an atomic group that contained a capturing parenthesis was
118        successfully matched, but the branch in which it appeared failed, the
119        capturing was not being forgotten if a higher numbered group was later
120        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121        group 1 to "a", when in fact it should be unset. This applied to multi-
122        branched capturing and non-capturing groups, repeated or not, and also to
123        positive assertions (capturing in negative assertions is not well defined
124        in PCRE) and also to nested atomic groups.
125    
126    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127        subject after a captured substring (to make it easier to tell which of a
128        number of identical substrings has been captured).
129    
130    24. The way atomic groups are processed by pcre_exec() has been changed so that
131        if they are repeated, backtracking one repetition now resets captured
132        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134        "aaa". Previously, it would have been "a". As part of this code
135        refactoring, the way recursive calls are handled has also been changed.
136    
137    24. If an assertion condition captured any substrings, they were not passed
138        back unless some other capturing happened later. For example, if
139        (?(?=(a))a) was matched against "a", no capturing was returned.
140    
141    25. When studying a pattern that contained subroutine calls or assertions,
142        the code for finding the minimum length of a possible match was handling
143        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
144        group 1 called group 2 while simultaneously a separate group 2 called group
145        1). A stack overflow occurred in this case. I have fixed this by limiting
146        the recursion depth to 10.
147    
148    26. Updated RunTest.bat in the distribution to the version supplied by Tom
149        Fortmann. This supports explicit test numbers on the command line, and has
150        argument validation and error reporting.
151    
152    27. An instance of \X with an unlimited repeat could fail if at any point the
153        first character it looked at was a mark character.
154    
155    28. Some minor code refactoring concerning Unicode properties and scripts
156        should reduce the stack requirement of match() slightly.
157    
158    29. Added the '=' option to pcretest to check the setting of unused capturing
159        slots at the end of the pattern, which are documented as being -1, but are
160        not included in the return count.
161    
162    30. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
163        compiled something random. Now it gives a compile-time error (as does
164        Perl).
165    
166    31. A *MARK encountered during the processing of a positive assertion is now
167        recorded and passed back (compatible with Perl).
168    
169    32. If --only-matching or --colour was set on a pcregrep call whose pattern
170        had alternative anchored branches, the search for a second match in a line
171        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
172        matched the line "0102" twice. The same bug affected patterns that started
173        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
174        twice.
175    
176    33. Previously, PCRE did not allow quantification of assertions. However, Perl
177        does, and because of capturing effects, quantifying parenthesized
178        assertions may at times be useful. Quantifiers are now allowed for
179        parenthesized assertions.
180    
181    34. A minor code tidy in pcre_compile() when checking options for \R usage.
182    
183    35. \g was being checked for fancy things in a character class, when it should
184        just be a literal "g".
185    
186    36. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
187        appearance of a nested POSIX class supersedes an apparent external class.
188        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
189        unescaped square brackets may also appear as part of class names. For
190        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
191        more like Perl.
192    
193    37. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
194        was because it thought it was \N{name}, which is not supported).
195    
196    38. Add minix to OS list not supporting the -S option in pcretest.
197    
198    
199    Version 8.12 15-Jan-2011
200    ------------------------
201    
202    1.  Fixed some typos in the markup of the man pages, and wrote a script that
203        checks for such things as part of the documentation building process.
204    
205    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
206        --match-limit and --recursion-limit options (added for 8.11). In
207        particular, this made one of the standard tests fail. (The integer value
208        went into the wrong half of a long int.)
209    
210    3.  If the --colour option was given to pcregrep with -v (invert match), it
211        did strange things, either producing crazy output, or crashing. It should,
212        of course, ignore a request for colour when reporting lines that do not
213        match.
214    
215    4.  Another pcregrep bug caused similar problems if --colour was specified with
216        -M (multiline) and the pattern match finished with a line ending.
217    
218    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
219        matched in multiline mode, the following line was shown as part of the
220        match. This seems wrong, so I have changed it.
221    
222    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
223        the check for further matches in the same line (so they could be coloured)
224        to overrun the end of the current line. If another match was found, it was
225        incorrectly shown (and then shown again when found in the next line).
226    
227    7.  If pcregrep was compiled under Windows, there was a reference to the
228        function pcregrep_exit() before it was defined. I am assuming this was
229        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
230        reported by a user. I've moved the definition above the reference.
231    
232    
233    Version 8.11 10-Dec-2010
234    ------------------------
235    
236    1.  (*THEN) was not working properly if there were untried alternatives prior
237        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
238        backtracked to try for "b" instead of moving to the next alternative branch
239        at the same level (in this case, to look for "c"). The Perl documentation
240        is clear that when (*THEN) is backtracked onto, it goes to the "next
241        alternative in the innermost enclosing group".
242    
243    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
244        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
245        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
246        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
247        (*THEN).
248    
249    3.  If \s appeared in a character class, it removed the VT character from
250        the class, even if it had been included by some previous item, for example
251        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
252        of \s, but is part of the POSIX "space" class.)
253    
254    4.  A partial match never returns an empty string (because you can always
255        match an empty string at the end of the subject); however the checking for
256        an empty string was starting at the "start of match" point. This has been
257        changed to the "earliest inspected character" point, because the returned
258        data for a partial match starts at this character. This means that, for
259        example, /(?<=abc)def/ gives a partial match for the subject "abc"
260        (previously it gave "no match").
261    
262    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
263        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
264        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
265        has an implication that the given string is incomplete (because a partial
266        match is preferred over a full match). For this reason, these items now
267        give a partial match in this situation. [Aside: previously, the one case
268        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
269        match rather than a full match, which was wrong by the old rules, but is
270        now correct.]
271    
272    6.  There was a bug in the handling of #-introduced comments, recognized when
273        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
274        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
275        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
276        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
277        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
278        places in pcre_compile().
279    
280    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
281        comments when looking ahead for named forward references to subpatterns,
282        the only newline sequence it recognized was NL. It now handles newlines
283        according to the set newline convention.
284    
285    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
286        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
287        cater for a lack of strerror(). These oversights have been fixed.
288    
289    9.  Added --match-limit and --recursion-limit to pcregrep.
290    
291    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
292    
293    11. When the -o option was used, pcregrep was setting a return code of 1, even
294        when matches were found, and --line-buffered was not being honoured.
295    
296    12. Added an optional parentheses number to the -o and --only-matching options
297        of pcregrep.
298    
299    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
300        can match an empty string. The code to do it in pcretest and pcredemo
301        needed fixing:
302    
303        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
304            only one byte after an empty string match just before CRLF (this case
305            just got forgotten; "any" and "anycrlf" were OK).
306    
307        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
308            mode when an empty string match preceded an ASCII character followed by
309            a non-ASCII character. (The code for advancing by one character rather
310            than one byte was nonsense.)
311    
312        (c) The pcredemo.c sample program did not have any code at all to handle
313            the cases when CRLF is a valid newline sequence.
314    
315    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
316        as a starting offset was within the subject string. There is now a new
317        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
318        negative or greater than the length of the string. In order to test this,
319        pcretest is extended to allow the setting of negative starting offsets.
320    
321    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
322        starting offset points to the beginning of a UTF-8 character was
323        unnecessarily clumsy. I tidied it up.
324    
325    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
326        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
327    
328    17. Nobody had reported that the --include_dir option, which was added in
329        release 7.7 should have been called --include-dir (hyphen, not underscore)
330        for compatibility with GNU grep. I have changed it to --include-dir, but
331        left --include_dir as an undocumented synonym, and the same for
332        --exclude-dir, though that is not available in GNU grep, at least as of
333        release 2.5.4.
334    
335    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
336        characters from a string of bytes) have been redefined so as not to use
337        loops, in order to improve performance in some environments. At the same
338        time, I abstracted some of the common code into auxiliary macros to save
339        repetition (this should not affect the compiled code).
340    
341    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
342        compile-time error is now given if \c is not followed by an ASCII
343        character, that is, a byte less than 128. (In EBCDIC mode, the code is
344        different, and any byte value is allowed.)
345    
346    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
347        START_OPTIMIZE option, which is now allowed at compile time - but just
348        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
349        to pcregrep and other applications that have no direct access to PCRE
350        options. The new /Y option in pcretest sets this option when calling
351        pcre_compile().
352    
353    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
354        back references. Groups containing recursive back references were forced to
355        be atomic by that change, but in the case of named groups, the amount of
356        memory required was incorrectly computed, leading to "Failed: internal
357        error: code overflow". This has been fixed.
358    
359    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
360        pcretest.c, to avoid build problems in some Borland environments.
361    
362    
363    Version 8.10 25-Jun-2010
364  ------------------------  ------------------------
365    
366  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 42  Version 8.10 03-Jun-2010 Line 401  Version 8.10 03-Jun-2010
401  11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was  11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
402      studied, and the match started with a letter with a code point greater than      studied, and the match started with a letter with a code point greater than
403      127 whose first byte was different to the first byte of the other case of      127 whose first byte was different to the first byte of the other case of
404      the letter, the other case of this starting letter was not recognized      the letter, the other case of this starting letter was not recognized
405      (#976).      (#976).
406    
407  12. If a pattern that was studied started with a repeated Unicode property  12. If a pattern that was studied started with a repeated Unicode property
# Line 68  Version 8.10 03-Jun-2010 Line 427  Version 8.10 03-Jun-2010
427    
428  17. Added a check for running out of memory when PCRE is compiled with  17. Added a check for running out of memory when PCRE is compiled with
429      --disable-stack-for-recursion (#990).      --disable-stack-for-recursion (#990).
430    
431  18. If the last data line in a file for pcretest does not have a newline on  18. If the last data line in a file for pcretest does not have a newline on
432      the end, a newline was missing in the output.      the end, a newline was missing in the output.
433    
434  19. The default pcre_chartables.c file recognizes only ASCII characters (values  19. The default pcre_chartables.c file recognizes only ASCII characters (values
435      less than 128) in its various bitmaps. However, there is a facility for      less than 128) in its various bitmaps. However, there is a facility for
436      generating tables according to the current locale when PCRE is compiled. It      generating tables according to the current locale when PCRE is compiled. It
437      turns out that in some environments, 0x85 and 0xa0, which are Unicode space      turns out that in some environments, 0x85 and 0xa0, which are Unicode space
438      characters, are recognized by isspace() and therefore were getting set in      characters, are recognized by isspace() and therefore were getting set in
439      these tables, and indeed these tables seem to approximate to ISO 8859. This      these tables, and indeed these tables seem to approximate to ISO 8859. This
440      caused a problem in UTF-8 mode when pcre_study() was used to create a list      caused a problem in UTF-8 mode when pcre_study() was used to create a list
441      of bytes that can start a match. For \s, it was including 0x85 and 0xa0,      of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
442      which of course cannot start UTF-8 characters. I have changed the code so      which of course cannot start UTF-8 characters. I have changed the code so
443      that only real ASCII characters (less than 128) and the correct starting      that only real ASCII characters (less than 128) and the correct starting
444      bytes for UTF-8 encodings are set for characters greater than 127 when in      bytes for UTF-8 encodings are set for characters greater than 127 when in
445      UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different      UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
446      altogether.)      altogether.)
447    
448  20. Added the /T option to pcretest so as to be able to run tests with non-  20. Added the /T option to pcretest so as to be able to run tests with non-
449      standard character tables, thus making it possible to include the tests      standard character tables, thus making it possible to include the tests
450      used for 19 above in the standard set of tests.      used for 19 above in the standard set of tests.
451    
452    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
453        reference to a subpattern the other side of a comment that contains an
454        opening parenthesis caused either an internal compiling error, or a
455        reference to the wrong subpattern.
456    
457    
458  Version 8.02 19-Mar-2010  Version 8.02 19-Mar-2010

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