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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-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    
57    Version 8.12 15-Jan-2011
58    ------------------------
59    
60    1.  Fixed some typos in the markup of the man pages, and wrote a script that
61        checks for such things as part of the documentation building process.
62    
63    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
64        --match-limit and --recursion-limit options (added for 8.11). In
65        particular, this made one of the standard tests fail. (The integer value
66        went into the wrong half of a long int.)
67    
68    3.  If the --colour option was given to pcregrep with -v (invert match), it
69        did strange things, either producing crazy output, or crashing. It should,
70        of course, ignore a request for colour when reporting lines that do not
71        match.
72    
73    4.  Another pcregrep bug caused similar problems if --colour was specified with
74        -M (multiline) and the pattern match finished with a line ending.
75    
76    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
77        matched in multiline mode, the following line was shown as part of the
78        match. This seems wrong, so I have changed it.
79    
80    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
81        the check for further matches in the same line (so they could be coloured)
82        to overrun the end of the current line. If another match was found, it was
83        incorrectly shown (and then shown again when found in the next line).
84    
85    7.  If pcregrep was compiled under Windows, there was a reference to the
86        function pcregrep_exit() before it was defined. I am assuming this was
87        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
88        reported by a user. I've moved the definition above the reference.
89    
90    
91    Version 8.11 10-Dec-2010
92    ------------------------
93    
94    1.  (*THEN) was not working properly if there were untried alternatives prior
95        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
96        backtracked to try for "b" instead of moving to the next alternative branch
97        at the same level (in this case, to look for "c"). The Perl documentation
98        is clear that when (*THEN) is backtracked onto, it goes to the "next
99        alternative in the innermost enclosing group".
100    
101    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
102        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
103        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
104        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
105        (*THEN).
106    
107    3.  If \s appeared in a character class, it removed the VT character from
108        the class, even if it had been included by some previous item, for example
109        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
110        of \s, but is part of the POSIX "space" class.)
111    
112    4.  A partial match never returns an empty string (because you can always
113        match an empty string at the end of the subject); however the checking for
114        an empty string was starting at the "start of match" point. This has been
115        changed to the "earliest inspected character" point, because the returned
116        data for a partial match starts at this character. This means that, for
117        example, /(?<=abc)def/ gives a partial match for the subject "abc"
118        (previously it gave "no match").
119    
120    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
121        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
122        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
123        has an implication that the given string is incomplete (because a partial
124        match is preferred over a full match). For this reason, these items now
125        give a partial match in this situation. [Aside: previously, the one case
126        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
127        match rather than a full match, which was wrong by the old rules, but is
128        now correct.]
129    
130    6.  There was a bug in the handling of #-introduced comments, recognized when
131        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
132        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
133        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
134        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
135        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
136        places in pcre_compile().
137    
138    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
139        comments when looking ahead for named forward references to subpatterns,
140        the only newline sequence it recognized was NL. It now handles newlines
141        according to the set newline convention.
142    
143    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
144        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
145        cater for a lack of strerror(). These oversights have been fixed.
146    
147    9.  Added --match-limit and --recursion-limit to pcregrep.
148    
149    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
150    
151    11. When the -o option was used, pcregrep was setting a return code of 1, even
152        when matches were found, and --line-buffered was not being honoured.
153    
154    12. Added an optional parentheses number to the -o and --only-matching options
155        of pcregrep.
156    
157    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
158        can match an empty string. The code to do it in pcretest and pcredemo
159        needed fixing:
160    
161        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
162            only one byte after an empty string match just before CRLF (this case
163            just got forgotten; "any" and "anycrlf" were OK).
164    
165        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
166            mode when an empty string match preceded an ASCII character followed by
167            a non-ASCII character. (The code for advancing by one character rather
168            than one byte was nonsense.)
169    
170        (c) The pcredemo.c sample program did not have any code at all to handle
171            the cases when CRLF is a valid newline sequence.
172    
173    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
174        as a starting offset was within the subject string. There is now a new
175        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
176        negative or greater than the length of the string. In order to test this,
177        pcretest is extended to allow the setting of negative starting offsets.
178    
179    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
180        starting offset points to the beginning of a UTF-8 character was
181        unnecessarily clumsy. I tidied it up.
182    
183    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
184        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
185    
186    17. Nobody had reported that the --include_dir option, which was added in
187        release 7.7 should have been called --include-dir (hyphen, not underscore)
188        for compatibility with GNU grep. I have changed it to --include-dir, but
189        left --include_dir as an undocumented synonym, and the same for
190        --exclude-dir, though that is not available in GNU grep, at least as of
191        release 2.5.4.
192    
193    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
194        characters from a string of bytes) have been redefined so as not to use
195        loops, in order to improve performance in some environments. At the same
196        time, I abstracted some of the common code into auxiliary macros to save
197        repetition (this should not affect the compiled code).
198    
199    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
200        compile-time error is now given if \c is not followed by an ASCII
201        character, that is, a byte less than 128. (In EBCDIC mode, the code is
202        different, and any byte value is allowed.)
203    
204    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
205        START_OPTIMIZE option, which is now allowed at compile time - but just
206        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
207        to pcregrep and other applications that have no direct access to PCRE
208        options. The new /Y option in pcretest sets this option when calling
209        pcre_compile().
210    
211    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
212        back references. Groups containing recursive back references were forced to
213        be atomic by that change, but in the case of named groups, the amount of
214        memory required was incorrectly computed, leading to "Failed: internal
215        error: code overflow". This has been fixed.
216    
217    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
218        pcretest.c, to avoid build problems in some Borland environments.
219    
220    
221    Version 8.10 25-Jun-2010
222    ------------------------
223    
224    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
225        THEN.
226    
227    2.  (*ACCEPT) was not working when inside an atomic group.
228    
229    3.  Inside a character class, \B is treated as a literal by default, but
230        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
231        causes the error). The code is unchanged, but I tidied the documentation.
232    
233    4.  Inside a character class, PCRE always treated \R and \X as literals,
234        whereas Perl faults them if its -w option is set. I have changed PCRE so
235        that it faults them when PCRE_EXTRA is set.
236    
237    5.  Added support for \N, which always matches any character other than
238        newline. (It is the same as "." when PCRE_DOTALL is not set.)
239    
240    6.  When compiling pcregrep with newer versions of gcc which may have
241        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
242        declared with attribute warn_unused_result" were given. Just casting the
243        result to (void) does not stop the warnings; a more elaborate fudge is
244        needed. I've used a macro to implement this.
245    
246    7.  Minor change to pcretest.c to avoid a compiler warning.
247    
248    8.  Added four artifical Unicode properties to help with an option to make
249        \s etc use properties (see next item). The new properties are: Xan
250        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
251    
252    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
253        use Unicode properties. (*UCP) at the start of a pattern can be used to set
254        this option. Modified pcretest to add /W to test this facility. Added
255        REG_UCP to make it available via the POSIX interface.
256    
257    10. Added --line-buffered to pcregrep.
258    
259    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
260        studied, and the match started with a letter with a code point greater than
261        127 whose first byte was different to the first byte of the other case of
262        the letter, the other case of this starting letter was not recognized
263        (#976).
264    
265    12. If a pattern that was studied started with a repeated Unicode property
266        test, for example, \p{Nd}+, there was the theoretical possibility of
267        setting up an incorrect bitmap of starting bytes, but fortunately it could
268        not have actually happened in practice until change 8 above was made (it
269        added property types that matched character-matching opcodes).
270    
271    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
272        possible starting bytes for non-anchored patterns.
273    
274    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
275        \R, and also a number of cases that involve Unicode properties, both
276        explicit and implicit when PCRE_UCP is set.
277    
278    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
279        input, it could crash or give wrong results if characters with values
280        greater than 0xc0 were present in the subject string. (Detail: it assumed
281        UTF-8 input when processing these items.)
282    
283    16. Added a lot of (int) casts to avoid compiler warnings in systems where
284        size_t is 64-bit (#991).
285    
286    17. Added a check for running out of memory when PCRE is compiled with
287        --disable-stack-for-recursion (#990).
288    
289    18. If the last data line in a file for pcretest does not have a newline on
290        the end, a newline was missing in the output.
291    
292    19. The default pcre_chartables.c file recognizes only ASCII characters (values
293        less than 128) in its various bitmaps. However, there is a facility for
294        generating tables according to the current locale when PCRE is compiled. It
295        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
296        characters, are recognized by isspace() and therefore were getting set in
297        these tables, and indeed these tables seem to approximate to ISO 8859. This
298        caused a problem in UTF-8 mode when pcre_study() was used to create a list
299        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
300        which of course cannot start UTF-8 characters. I have changed the code so
301        that only real ASCII characters (less than 128) and the correct starting
302        bytes for UTF-8 encodings are set for characters greater than 127 when in
303        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
304        altogether.)
305    
306    20. Added the /T option to pcretest so as to be able to run tests with non-
307        standard character tables, thus making it possible to include the tests
308        used for 19 above in the standard set of tests.
309    
310    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
311        reference to a subpattern the other side of a comment that contains an
312        opening parenthesis caused either an internal compiling error, or a
313        reference to the wrong subpattern.
314    
315    
316    Version 8.02 19-Mar-2010
317  ------------------------  ------------------------
318    
319  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
320    
321  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
322      configured.      configured.
323    
324  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
325      original author of that file, following a query about its status.      original author of that file, following a query about its status.
326    
327  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
328      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
329    
330    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
331        quantifier applied to a forward-referencing subroutine call, could compile
332        incorrect code or give the error "internal error: previously-checked
333        referenced subpattern not found".
334    
335    6.  Both MS Visual Studio and Symbian OS have problems with initializing
336        variables to point to external functions. For these systems, therefore,
337        pcre_malloc etc. are now initialized to local functions that call the
338        relevant global functions.
339    
340    7.  There were two entries missing in the vectors called coptable and poptable
341        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
342        I've fixed the data, and added a kludgy way of testing at compile time that
343        the lengths are correct (equal to the number of opcodes).
344    
345    8.  Following on from 7, I added a similar kludge to check the length of the
346        eint vector in pcreposix.c.
347    
348    9.  Error texts for pcre_compile() are held as one long string to avoid too
349        much relocation at load time. To find a text, the string is searched,
350        counting zeros. There was no check for running off the end of the string,
351        which could happen if a new error number was added without updating the
352        string.
353    
354    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
355    
356    11. \K was not working if it appeared in an atomic group or in a group that
357        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
358        \K is "not well defined" if used in an assertion. PCRE now accepts it if
359        the assertion is positive, but not if it is negative.
360    
361    12. Change 11 fortuitously reduced the size of the stack frame used in the
362        "match()" function of pcre_exec.c by one pointer. Forthcoming
363        implementation of support for (*MARK) will need an extra pointer on the
364        stack; I have reserved it now, so that the stack frame size does not
365        decrease.
366    
367    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
368        item in branch that calls a recursion is a subroutine call - as in the
369        second branch in the above example - was incorrectly given the compile-
370        time error "recursive call could loop indefinitely" because pcre_compile()
371        was not correctly checking the subroutine for matching a non-empty string.
372    
373    14. The checks for overrunning compiling workspace could trigger after an
374        overrun had occurred. This is a "should never occur" error, but it can be
375        triggered by pathological patterns such as hundreds of nested parentheses.
376        The checks now trigger 100 bytes before the end of the workspace.
377    
378    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
379    
380    
381  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
382  ------------------------  ------------------------

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