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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    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    
86    Version 8.12 15-Jan-2011
87    ------------------------
88    
89    1.  Fixed some typos in the markup of the man pages, and wrote a script that
90        checks for such things as part of the documentation building process.
91    
92    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
93        --match-limit and --recursion-limit options (added for 8.11). In
94        particular, this made one of the standard tests fail. (The integer value
95        went into the wrong half of a long int.)
96    
97    3.  If the --colour option was given to pcregrep with -v (invert match), it
98        did strange things, either producing crazy output, or crashing. It should,
99        of course, ignore a request for colour when reporting lines that do not
100        match.
101    
102    4.  Another pcregrep bug caused similar problems if --colour was specified with
103        -M (multiline) and the pattern match finished with a line ending.
104    
105    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
106        matched in multiline mode, the following line was shown as part of the
107        match. This seems wrong, so I have changed it.
108    
109    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
110        the check for further matches in the same line (so they could be coloured)
111        to overrun the end of the current line. If another match was found, it was
112        incorrectly shown (and then shown again when found in the next line).
113    
114    7.  If pcregrep was compiled under Windows, there was a reference to the
115        function pcregrep_exit() before it was defined. I am assuming this was
116        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
117        reported by a user. I've moved the definition above the reference.
118    
119    
120    Version 8.11 10-Dec-2010
121    ------------------------
122    
123    1.  (*THEN) was not working properly if there were untried alternatives prior
124        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
125        backtracked to try for "b" instead of moving to the next alternative branch
126        at the same level (in this case, to look for "c"). The Perl documentation
127        is clear that when (*THEN) is backtracked onto, it goes to the "next
128        alternative in the innermost enclosing group".
129    
130    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
131        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
132        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
133        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
134        (*THEN).
135    
136    3.  If \s appeared in a character class, it removed the VT character from
137        the class, even if it had been included by some previous item, for example
138        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
139        of \s, but is part of the POSIX "space" class.)
140    
141    4.  A partial match never returns an empty string (because you can always
142        match an empty string at the end of the subject); however the checking for
143        an empty string was starting at the "start of match" point. This has been
144        changed to the "earliest inspected character" point, because the returned
145        data for a partial match starts at this character. This means that, for
146        example, /(?<=abc)def/ gives a partial match for the subject "abc"
147        (previously it gave "no match").
148    
149    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
150        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
151        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
152        has an implication that the given string is incomplete (because a partial
153        match is preferred over a full match). For this reason, these items now
154        give a partial match in this situation. [Aside: previously, the one case
155        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
156        match rather than a full match, which was wrong by the old rules, but is
157        now correct.]
158    
159    6.  There was a bug in the handling of #-introduced comments, recognized when
160        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
161        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
162        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
163        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
164        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
165        places in pcre_compile().
166    
167    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
168        comments when looking ahead for named forward references to subpatterns,
169        the only newline sequence it recognized was NL. It now handles newlines
170        according to the set newline convention.
171    
172    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
173        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
174        cater for a lack of strerror(). These oversights have been fixed.
175    
176    9.  Added --match-limit and --recursion-limit to pcregrep.
177    
178    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
179    
180    11. When the -o option was used, pcregrep was setting a return code of 1, even
181        when matches were found, and --line-buffered was not being honoured.
182    
183    12. Added an optional parentheses number to the -o and --only-matching options
184        of pcregrep.
185    
186    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
187        can match an empty string. The code to do it in pcretest and pcredemo
188        needed fixing:
189    
190        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
191            only one byte after an empty string match just before CRLF (this case
192            just got forgotten; "any" and "anycrlf" were OK).
193    
194        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
195            mode when an empty string match preceded an ASCII character followed by
196            a non-ASCII character. (The code for advancing by one character rather
197            than one byte was nonsense.)
198    
199        (c) The pcredemo.c sample program did not have any code at all to handle
200            the cases when CRLF is a valid newline sequence.
201    
202    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
203        as a starting offset was within the subject string. There is now a new
204        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
205        negative or greater than the length of the string. In order to test this,
206        pcretest is extended to allow the setting of negative starting offsets.
207    
208    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
209        starting offset points to the beginning of a UTF-8 character was
210        unnecessarily clumsy. I tidied it up.
211    
212    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
213        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
214    
215    17. Nobody had reported that the --include_dir option, which was added in
216        release 7.7 should have been called --include-dir (hyphen, not underscore)
217        for compatibility with GNU grep. I have changed it to --include-dir, but
218        left --include_dir as an undocumented synonym, and the same for
219        --exclude-dir, though that is not available in GNU grep, at least as of
220        release 2.5.4.
221    
222    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
223        characters from a string of bytes) have been redefined so as not to use
224        loops, in order to improve performance in some environments. At the same
225        time, I abstracted some of the common code into auxiliary macros to save
226        repetition (this should not affect the compiled code).
227    
228    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
229        compile-time error is now given if \c is not followed by an ASCII
230        character, that is, a byte less than 128. (In EBCDIC mode, the code is
231        different, and any byte value is allowed.)
232    
233    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
234        START_OPTIMIZE option, which is now allowed at compile time - but just
235        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
236        to pcregrep and other applications that have no direct access to PCRE
237        options. The new /Y option in pcretest sets this option when calling
238        pcre_compile().
239    
240    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
241        back references. Groups containing recursive back references were forced to
242        be atomic by that change, but in the case of named groups, the amount of
243        memory required was incorrectly computed, leading to "Failed: internal
244        error: code overflow". This has been fixed.
245    
246    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
247        pcretest.c, to avoid build problems in some Borland environments.
248    
249    
250    Version 8.10 25-Jun-2010
251    ------------------------
252    
253    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
254        THEN.
255    
256    2.  (*ACCEPT) was not working when inside an atomic group.
257    
258    3.  Inside a character class, \B is treated as a literal by default, but
259        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
260        causes the error). The code is unchanged, but I tidied the documentation.
261    
262    4.  Inside a character class, PCRE always treated \R and \X as literals,
263        whereas Perl faults them if its -w option is set. I have changed PCRE so
264        that it faults them when PCRE_EXTRA is set.
265    
266    5.  Added support for \N, which always matches any character other than
267        newline. (It is the same as "." when PCRE_DOTALL is not set.)
268    
269    6.  When compiling pcregrep with newer versions of gcc which may have
270        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
271        declared with attribute warn_unused_result" were given. Just casting the
272        result to (void) does not stop the warnings; a more elaborate fudge is
273        needed. I've used a macro to implement this.
274    
275    7.  Minor change to pcretest.c to avoid a compiler warning.
276    
277    8.  Added four artifical Unicode properties to help with an option to make
278        \s etc use properties (see next item). The new properties are: Xan
279        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
280    
281    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
282        use Unicode properties. (*UCP) at the start of a pattern can be used to set
283        this option. Modified pcretest to add /W to test this facility. Added
284        REG_UCP to make it available via the POSIX interface.
285    
286    10. Added --line-buffered to pcregrep.
287    
288    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
289        studied, and the match started with a letter with a code point greater than
290        127 whose first byte was different to the first byte of the other case of
291        the letter, the other case of this starting letter was not recognized
292        (#976).
293    
294    12. If a pattern that was studied started with a repeated Unicode property
295        test, for example, \p{Nd}+, there was the theoretical possibility of
296        setting up an incorrect bitmap of starting bytes, but fortunately it could
297        not have actually happened in practice until change 8 above was made (it
298        added property types that matched character-matching opcodes).
299    
300    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
301        possible starting bytes for non-anchored patterns.
302    
303    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
304        \R, and also a number of cases that involve Unicode properties, both
305        explicit and implicit when PCRE_UCP is set.
306    
307    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
308        input, it could crash or give wrong results if characters with values
309        greater than 0xc0 were present in the subject string. (Detail: it assumed
310        UTF-8 input when processing these items.)
311    
312    16. Added a lot of (int) casts to avoid compiler warnings in systems where
313        size_t is 64-bit (#991).
314    
315    17. Added a check for running out of memory when PCRE is compiled with
316        --disable-stack-for-recursion (#990).
317    
318    18. If the last data line in a file for pcretest does not have a newline on
319        the end, a newline was missing in the output.
320    
321    19. The default pcre_chartables.c file recognizes only ASCII characters (values
322        less than 128) in its various bitmaps. However, there is a facility for
323        generating tables according to the current locale when PCRE is compiled. It
324        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
325        characters, are recognized by isspace() and therefore were getting set in
326        these tables, and indeed these tables seem to approximate to ISO 8859. This
327        caused a problem in UTF-8 mode when pcre_study() was used to create a list
328        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
329        which of course cannot start UTF-8 characters. I have changed the code so
330        that only real ASCII characters (less than 128) and the correct starting
331        bytes for UTF-8 encodings are set for characters greater than 127 when in
332        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
333        altogether.)
334    
335    20. Added the /T option to pcretest so as to be able to run tests with non-
336        standard character tables, thus making it possible to include the tests
337        used for 19 above in the standard set of tests.
338    
339    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
340        reference to a subpattern the other side of a comment that contains an
341        opening parenthesis caused either an internal compiling error, or a
342        reference to the wrong subpattern.
343    
344    
345    Version 8.02 19-Mar-2010
346  ------------------------  ------------------------
347    
348  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.
349    
350  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
351      configured.      configured.
352    
353  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
354      original author of that file, following a query about its status.      original author of that file, following a query about its status.
355    
356  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
357      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.
358    
359  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
360      quantifier applied to a forward-referencing subroutine call, could compile      quantifier applied to a forward-referencing subroutine call, could compile
361      incorrect code or give the error "internal error: previously-checked      incorrect code or give the error "internal error: previously-checked
362      referenced subpattern not found".      referenced subpattern not found".
363    
364    6.  Both MS Visual Studio and Symbian OS have problems with initializing
365        variables to point to external functions. For these systems, therefore,
366        pcre_malloc etc. are now initialized to local functions that call the
367        relevant global functions.
368    
369    7.  There were two entries missing in the vectors called coptable and poptable
370        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
371        I've fixed the data, and added a kludgy way of testing at compile time that
372        the lengths are correct (equal to the number of opcodes).
373    
374    8.  Following on from 7, I added a similar kludge to check the length of the
375        eint vector in pcreposix.c.
376    
377    9.  Error texts for pcre_compile() are held as one long string to avoid too
378        much relocation at load time. To find a text, the string is searched,
379        counting zeros. There was no check for running off the end of the string,
380        which could happen if a new error number was added without updating the
381        string.
382    
383    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
384    
385    11. \K was not working if it appeared in an atomic group or in a group that
386        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
387        \K is "not well defined" if used in an assertion. PCRE now accepts it if
388        the assertion is positive, but not if it is negative.
389    
390    12. Change 11 fortuitously reduced the size of the stack frame used in the
391        "match()" function of pcre_exec.c by one pointer. Forthcoming
392        implementation of support for (*MARK) will need an extra pointer on the
393        stack; I have reserved it now, so that the stack frame size does not
394        decrease.
395    
396    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
397        item in branch that calls a recursion is a subroutine call - as in the
398        second branch in the above example - was incorrectly given the compile-
399        time error "recursive call could loop indefinitely" because pcre_compile()
400        was not correctly checking the subroutine for matching a non-empty string.
401    
402    14. The checks for overrunning compiling workspace could trigger after an
403        overrun had occurred. This is a "should never occur" error, but it can be
404        triggered by pathological patterns such as hundreds of nested parentheses.
405        The checks now trigger 100 bytes before the end of the workspace.
406    
407    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
408    
409    
410  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
411  ------------------------  ------------------------

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