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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 01-May-07  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    
149    Version 8.12 15-Jan-2011
150    ------------------------
151    
152    1.  Fixed some typos in the markup of the man pages, and wrote a script that
153        checks for such things as part of the documentation building process.
154    
155    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
156        --match-limit and --recursion-limit options (added for 8.11). In
157        particular, this made one of the standard tests fail. (The integer value
158        went into the wrong half of a long int.)
159    
160    3.  If the --colour option was given to pcregrep with -v (invert match), it
161        did strange things, either producing crazy output, or crashing. It should,
162        of course, ignore a request for colour when reporting lines that do not
163        match.
164    
165    4.  Another pcregrep bug caused similar problems if --colour was specified with
166        -M (multiline) and the pattern match finished with a line ending.
167    
168    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
169        matched in multiline mode, the following line was shown as part of the
170        match. This seems wrong, so I have changed it.
171    
172    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
173        the check for further matches in the same line (so they could be coloured)
174        to overrun the end of the current line. If another match was found, it was
175        incorrectly shown (and then shown again when found in the next line).
176    
177    7.  If pcregrep was compiled under Windows, there was a reference to the
178        function pcregrep_exit() before it was defined. I am assuming this was
179        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
180        reported by a user. I've moved the definition above the reference.
181    
182    
183    Version 8.11 10-Dec-2010
184    ------------------------
185    
186    1.  (*THEN) was not working properly if there were untried alternatives prior
187        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
188        backtracked to try for "b" instead of moving to the next alternative branch
189        at the same level (in this case, to look for "c"). The Perl documentation
190        is clear that when (*THEN) is backtracked onto, it goes to the "next
191        alternative in the innermost enclosing group".
192    
193    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
194        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
195        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
196        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
197        (*THEN).
198    
199    3.  If \s appeared in a character class, it removed the VT character from
200        the class, even if it had been included by some previous item, for example
201        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
202        of \s, but is part of the POSIX "space" class.)
203    
204    4.  A partial match never returns an empty string (because you can always
205        match an empty string at the end of the subject); however the checking for
206        an empty string was starting at the "start of match" point. This has been
207        changed to the "earliest inspected character" point, because the returned
208        data for a partial match starts at this character. This means that, for
209        example, /(?<=abc)def/ gives a partial match for the subject "abc"
210        (previously it gave "no match").
211    
212    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
213        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
214        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
215        has an implication that the given string is incomplete (because a partial
216        match is preferred over a full match). For this reason, these items now
217        give a partial match in this situation. [Aside: previously, the one case
218        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
219        match rather than a full match, which was wrong by the old rules, but is
220        now correct.]
221    
222    6.  There was a bug in the handling of #-introduced comments, recognized when
223        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
224        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
225        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
226        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
227        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
228        places in pcre_compile().
229    
230    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
231        comments when looking ahead for named forward references to subpatterns,
232        the only newline sequence it recognized was NL. It now handles newlines
233        according to the set newline convention.
234    
235    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
236        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
237        cater for a lack of strerror(). These oversights have been fixed.
238    
239    9.  Added --match-limit and --recursion-limit to pcregrep.
240    
241    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
242    
243    11. When the -o option was used, pcregrep was setting a return code of 1, even
244        when matches were found, and --line-buffered was not being honoured.
245    
246    12. Added an optional parentheses number to the -o and --only-matching options
247        of pcregrep.
248    
249    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
250        can match an empty string. The code to do it in pcretest and pcredemo
251        needed fixing:
252    
253        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
254            only one byte after an empty string match just before CRLF (this case
255            just got forgotten; "any" and "anycrlf" were OK).
256    
257        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
258            mode when an empty string match preceded an ASCII character followed by
259            a non-ASCII character. (The code for advancing by one character rather
260            than one byte was nonsense.)
261    
262        (c) The pcredemo.c sample program did not have any code at all to handle
263            the cases when CRLF is a valid newline sequence.
264    
265    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
266        as a starting offset was within the subject string. There is now a new
267        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
268        negative or greater than the length of the string. In order to test this,
269        pcretest is extended to allow the setting of negative starting offsets.
270    
271    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
272        starting offset points to the beginning of a UTF-8 character was
273        unnecessarily clumsy. I tidied it up.
274    
275    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
276        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
277    
278    17. Nobody had reported that the --include_dir option, which was added in
279        release 7.7 should have been called --include-dir (hyphen, not underscore)
280        for compatibility with GNU grep. I have changed it to --include-dir, but
281        left --include_dir as an undocumented synonym, and the same for
282        --exclude-dir, though that is not available in GNU grep, at least as of
283        release 2.5.4.
284    
285    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
286        characters from a string of bytes) have been redefined so as not to use
287        loops, in order to improve performance in some environments. At the same
288        time, I abstracted some of the common code into auxiliary macros to save
289        repetition (this should not affect the compiled code).
290    
291    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
292        compile-time error is now given if \c is not followed by an ASCII
293        character, that is, a byte less than 128. (In EBCDIC mode, the code is
294        different, and any byte value is allowed.)
295    
296    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
297        START_OPTIMIZE option, which is now allowed at compile time - but just
298        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
299        to pcregrep and other applications that have no direct access to PCRE
300        options. The new /Y option in pcretest sets this option when calling
301        pcre_compile().
302    
303    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
304        back references. Groups containing recursive back references were forced to
305        be atomic by that change, but in the case of named groups, the amount of
306        memory required was incorrectly computed, leading to "Failed: internal
307        error: code overflow". This has been fixed.
308    
309    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
310        pcretest.c, to avoid build problems in some Borland environments.
311    
312    
313    Version 8.10 25-Jun-2010
314    ------------------------
315    
316    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
317        THEN.
318    
319    2.  (*ACCEPT) was not working when inside an atomic group.
320    
321    3.  Inside a character class, \B is treated as a literal by default, but
322        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
323        causes the error). The code is unchanged, but I tidied the documentation.
324    
325    4.  Inside a character class, PCRE always treated \R and \X as literals,
326        whereas Perl faults them if its -w option is set. I have changed PCRE so
327        that it faults them when PCRE_EXTRA is set.
328    
329    5.  Added support for \N, which always matches any character other than
330        newline. (It is the same as "." when PCRE_DOTALL is not set.)
331    
332    6.  When compiling pcregrep with newer versions of gcc which may have
333        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
334        declared with attribute warn_unused_result" were given. Just casting the
335        result to (void) does not stop the warnings; a more elaborate fudge is
336        needed. I've used a macro to implement this.
337    
338    7.  Minor change to pcretest.c to avoid a compiler warning.
339    
340    8.  Added four artifical Unicode properties to help with an option to make
341        \s etc use properties (see next item). The new properties are: Xan
342        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
343    
344    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
345        use Unicode properties. (*UCP) at the start of a pattern can be used to set
346        this option. Modified pcretest to add /W to test this facility. Added
347        REG_UCP to make it available via the POSIX interface.
348    
349    10. Added --line-buffered to pcregrep.
350    
351    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
352        studied, and the match started with a letter with a code point greater than
353        127 whose first byte was different to the first byte of the other case of
354        the letter, the other case of this starting letter was not recognized
355        (#976).
356    
357    12. If a pattern that was studied started with a repeated Unicode property
358        test, for example, \p{Nd}+, there was the theoretical possibility of
359        setting up an incorrect bitmap of starting bytes, but fortunately it could
360        not have actually happened in practice until change 8 above was made (it
361        added property types that matched character-matching opcodes).
362    
363    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
364        possible starting bytes for non-anchored patterns.
365    
366    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
367        \R, and also a number of cases that involve Unicode properties, both
368        explicit and implicit when PCRE_UCP is set.
369    
370    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
371        input, it could crash or give wrong results if characters with values
372        greater than 0xc0 were present in the subject string. (Detail: it assumed
373        UTF-8 input when processing these items.)
374    
375    16. Added a lot of (int) casts to avoid compiler warnings in systems where
376        size_t is 64-bit (#991).
377    
378    17. Added a check for running out of memory when PCRE is compiled with
379        --disable-stack-for-recursion (#990).
380    
381    18. If the last data line in a file for pcretest does not have a newline on
382        the end, a newline was missing in the output.
383    
384    19. The default pcre_chartables.c file recognizes only ASCII characters (values
385        less than 128) in its various bitmaps. However, there is a facility for
386        generating tables according to the current locale when PCRE is compiled. It
387        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
388        characters, are recognized by isspace() and therefore were getting set in
389        these tables, and indeed these tables seem to approximate to ISO 8859. This
390        caused a problem in UTF-8 mode when pcre_study() was used to create a list
391        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
392        which of course cannot start UTF-8 characters. I have changed the code so
393        that only real ASCII characters (less than 128) and the correct starting
394        bytes for UTF-8 encodings are set for characters greater than 127 when in
395        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
396        altogether.)
397    
398    20. Added the /T option to pcretest so as to be able to run tests with non-
399        standard character tables, thus making it possible to include the tests
400        used for 19 above in the standard set of tests.
401    
402    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
403        reference to a subpattern the other side of a comment that contains an
404        opening parenthesis caused either an internal compiling error, or a
405        reference to the wrong subpattern.
406    
407    
408    Version 8.02 19-Mar-2010
409    ------------------------
410    
411    1.  The Unicode data tables have been updated to Unicode 5.2.0.
412    
413    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
414        configured.
415    
416    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
417        original author of that file, following a query about its status.
418    
419    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
420        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
421    
422    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
423        quantifier applied to a forward-referencing subroutine call, could compile
424        incorrect code or give the error "internal error: previously-checked
425        referenced subpattern not found".
426    
427    6.  Both MS Visual Studio and Symbian OS have problems with initializing
428        variables to point to external functions. For these systems, therefore,
429        pcre_malloc etc. are now initialized to local functions that call the
430        relevant global functions.
431    
432    7.  There were two entries missing in the vectors called coptable and poptable
433        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
434        I've fixed the data, and added a kludgy way of testing at compile time that
435        the lengths are correct (equal to the number of opcodes).
436    
437    8.  Following on from 7, I added a similar kludge to check the length of the
438        eint vector in pcreposix.c.
439    
440    9.  Error texts for pcre_compile() are held as one long string to avoid too
441        much relocation at load time. To find a text, the string is searched,
442        counting zeros. There was no check for running off the end of the string,
443        which could happen if a new error number was added without updating the
444        string.
445    
446    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
447    
448    11. \K was not working if it appeared in an atomic group or in a group that
449        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
450        \K is "not well defined" if used in an assertion. PCRE now accepts it if
451        the assertion is positive, but not if it is negative.
452    
453    12. Change 11 fortuitously reduced the size of the stack frame used in the
454        "match()" function of pcre_exec.c by one pointer. Forthcoming
455        implementation of support for (*MARK) will need an extra pointer on the
456        stack; I have reserved it now, so that the stack frame size does not
457        decrease.
458    
459    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
460        item in branch that calls a recursion is a subroutine call - as in the
461        second branch in the above example - was incorrectly given the compile-
462        time error "recursive call could loop indefinitely" because pcre_compile()
463        was not correctly checking the subroutine for matching a non-empty string.
464    
465    14. The checks for overrunning compiling workspace could trigger after an
466        overrun had occurred. This is a "should never occur" error, but it can be
467        triggered by pathological patterns such as hundreds of nested parentheses.
468        The checks now trigger 100 bytes before the end of the workspace.
469    
470    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
471    
472    
473    Version 8.01 19-Jan-2010
474    ------------------------
475    
476    1.  If a pattern contained a conditional subpattern with only one branch (in
477        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
478        computed the wrong minimum data length (which is of course zero for such
479        subpatterns). This could cause incorrect "no match" results.
480    
481    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
482        the pattern is reset in the first branch, pcre_compile() failed with
483        "internal error: code overflow at offset...". This happened only when
484        the reset was to the original external option setting. (An optimization
485        abstracts leading options settings into an external setting, which was the
486        cause of this.)
487    
488    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
489        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
490        assertion pattern did not match (meaning that the assertion was true), it
491        was incorrectly treated as false if the SKIP had been reached during the
492        matching. This also applied to assertions used as conditions.
493    
494    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
495        assertion subpattern, including such a pattern used as a condition,
496        unpredictable results occurred, instead of the error return
497        PCRE_ERROR_DFA_UITEM.
498    
499    5.  The C++ GlobalReplace function was not working like Perl for the special
500        situation when an empty string is matched. It now does the fancy magic
501        stuff that is necessary.
502    
503    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
504        removed. (These were left over from very, very early versions of PCRE.)
505    
506    7.  Some cosmetic changes to the code to make life easier when compiling it
507        as part of something else:
508    
509        (a) Change DEBUG to PCRE_DEBUG.
510    
511        (b) In pcre_compile(), rename the member of the "branch_chain" structure
512            called "current" as "current_branch", to prevent a collision with the
513            Linux macro when compiled as a kernel module.
514    
515        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
516            prevent a collision with the Linux macro when compiled as a kernel
517            module.
518    
519    8.  In pcre_compile() there are some checks for integer overflows that used to
520        cast potentially large values to (double). This has been changed to that
521        when building, a check for int64_t is made, and if it is found, it is used
522        instead, thus avoiding the use of floating point arithmetic. (There is no
523        other use of FP in PCRE.) If int64_t is not found, the fallback is to
524        double.
525    
526    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
527        2005 (difference between two addresses compared to an unsigned value).
528    
529    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
530        custom one, because of the following reported problem in Windows:
531    
532          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
533              under Win32.
534          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
535              therefore missing the function definition.
536          - The compiler thus generates a "C" signature for the test function.
537          - The linker fails to find the "C" function.
538          - PCRE fails to configure if asked to do so against libbz2.
539    
540    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
541        messages were output:
542    
543          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
544          rerunning libtoolize, to keep the correct libtool macros in-tree.
545          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
546    
547        I have done both of these things.
548    
549    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
550        most of the time, it *can* run out if it is given a pattern that contains a
551        runaway infinite recursion. I updated the discussion in the pcrestack man
552        page.
553    
554    13. Now that we have gone to the x.xx style of version numbers, the minor
555        version may start with zero. Using 08 or 09 is a bad idea because users
556        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
557        interpreted as invalid octal numbers. I've updated the previous comment in
558        configure.ac, and also added a check that gives an error if 08 or 09 are
559        used.
560    
561    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
562        causing partial matching to fail when the end of the subject matched \W
563        in a UTF-8 pattern where \W was quantified with a minimum of 3.
564    
565    15. There were some discrepancies between the declarations in pcre_internal.h
566        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
567        their definitions. The declarations used "const uschar *" and the
568        definitions used USPTR. Even though USPTR is normally defined as "const
569        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
570        reported that: "This difference in casting confuses some C++ compilers, for
571        example, SunCC recognizes above declarations as different functions and
572        generates broken code for hbpcre." I have changed the declarations to use
573        USPTR.
574    
575    16. GNU libtool is named differently on some systems. The autogen.sh script now
576        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
577        (FreeBSD).
578    
579    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
580        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
581        comment: "Figure out how to create a longlong from a string: strtoll and
582        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
583        instance, but it only takes 2 args instead of 3!"
584    
585    18. A subtle bug concerned with back references has been fixed by a change of
586        specification, with a corresponding code fix. A pattern such as
587        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
588        refers, was giving matches when it shouldn't. For example, xa=xaaa would
589        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
590        same bug. Such groups have to be quantified to be useful, or contained
591        inside another quantified group. (If there's no repetition, the reference
592        can never match.) The problem arises because, having left the group and
593        moved on to the rest of the pattern, a later failure that backtracks into
594        the group uses the captured value from the final iteration of the group
595        rather than the correct earlier one. I have fixed this in PCRE by forcing
596        any group that contains a reference to itself to be an atomic group; that
597        is, there cannot be any backtracking into it once it has completed. This is
598        similar to recursive and subroutine calls.
599    
600    
601    Version 8.00 19-Oct-09
602    ----------------------
603    
604    1.  The table for translating pcre_compile() error codes into POSIX error codes
605        was out-of-date, and there was no check on the pcre_compile() error code
606        being within the table. This could lead to an OK return being given in
607        error.
608    
609    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
610        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
611        in a Windows environment.
612    
613    3.  The pcregrep --count option prints the count for each file even when it is
614        zero, as does GNU grep. However, pcregrep was also printing all files when
615        --files-with-matches was added. Now, when both options are given, it prints
616        counts only for those files that have at least one match. (GNU grep just
617        prints the file name in this circumstance, but including the count seems
618        more useful - otherwise, why use --count?) Also ensured that the
619        combination -clh just lists non-zero counts, with no names.
620    
621    4.  The long form of the pcregrep -F option was incorrectly implemented as
622        --fixed_strings instead of --fixed-strings. This is an incompatible change,
623        but it seems right to fix it, and I didn't think it was worth preserving
624        the old behaviour.
625    
626    5.  The command line items --regex=pattern and --regexp=pattern were not
627        recognized by pcregrep, which required --regex pattern or --regexp pattern
628        (with a space rather than an '='). The man page documented the '=' forms,
629        which are compatible with GNU grep; these now work.
630    
631    6.  No libpcreposix.pc file was created for pkg-config; there was just
632        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
633    
634    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
635        when UCP support is not needed, by modifying the Python script that
636        generates it from Unicode data files. This should not matter if the module
637        is correctly used as a library, but I received one complaint about 50K of
638        unwanted data. My guess is that the person linked everything into his
639        program rather than using a library. Anyway, it does no harm.
640    
641    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
642        was a minimum greater than 1 for a wide character in a possessive
643        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
644        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
645        character. Chaos in the form of incorrect output or a compiling loop could
646        result.
647    
648    9.  The restrictions on what a pattern can contain when partial matching is
649        requested for pcre_exec() have been removed. All patterns can now be
650        partially matched by this function. In addition, if there are at least two
651        slots in the offset vector, the offset of the earliest inspected character
652        for the match and the offset of the end of the subject are set in them when
653        PCRE_ERROR_PARTIAL is returned.
654    
655    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
656        synonymous with PCRE_PARTIAL, for backwards compatibility, and
657        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
658        and may be more useful for multi-segment matching.
659    
660    11. Partial matching with pcre_exec() is now more intuitive. A partial match
661        used to be given if ever the end of the subject was reached; now it is
662        given only if matching could not proceed because another character was
663        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
664        string "Z", which now yields "no match" instead of "partial match". In the
665        case of pcre_dfa_exec(), "no match" is given if every matching path for the
666        final character ended with (*FAIL).
667    
668    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
669        if the pattern had a "must contain" character that was already found in the
670        earlier partial match, unless partial matching was again requested. For
671        example, with the pattern /dog.(body)?/, the "must contain" character is
672        "g". If the first part-match was for the string "dog", restarting with
673        "sbody" failed. This bug has been fixed.
674    
675    13. The string returned by pcre_dfa_exec() after a partial match has been
676        changed so that it starts at the first inspected character rather than the
677        first character of the match. This makes a difference only if the pattern
678        starts with a lookbehind assertion or \b or \B (\K is not supported by
679        pcre_dfa_exec()). It's an incompatible change, but it makes the two
680        matching functions compatible, and I think it's the right thing to do.
681    
682    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
683        so that the demonstration program is easily available in environments where
684        PCRE has not been installed from source.
685    
686    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
687        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
688        library.
689    
690    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
691        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
692        is not the first non-POSIX option to be added. Clearly some people find
693        these options useful.
694    
695    17. If a caller to the POSIX matching function regexec() passes a non-zero
696        value for nmatch with a NULL value for pmatch, the value of
697        nmatch is forced to zero.
698    
699    18. RunGrepTest did not have a test for the availability of the -u option of
700        the diff command, as RunTest does. It now checks in the same way as
701        RunTest, and also checks for the -b option.
702    
703    19. If an odd number of negated classes containing just a single character
704        interposed, within parentheses, between a forward reference to a named
705        subpattern and the definition of the subpattern, compilation crashed with
706        an internal error, complaining that it could not find the referenced
707        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
708        [The bug was that it was starting one character too far in when skipping
709        over the character class, thus treating the ] as data rather than
710        terminating the class. This meant it could skip too much.]
711    
712    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
713        /g option in pcretest when the pattern contains \K, which makes it possible
714        to have an empty string match not at the start, even when the pattern is
715        anchored. Updated pcretest and pcredemo to use this option.
716    
717    21. If the maximum number of capturing subpatterns in a recursion was greater
718        than the maximum at the outer level, the higher number was returned, but
719        with unset values at the outer level. The correct (outer level) value is
720        now given.
721    
722    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
723        PCRE did not set those parentheses (unlike Perl). I have now found a way to
724        make it do so. The string so far is captured, making this feature
725        compatible with Perl.
726    
727    23. The tests have been re-organized, adding tests 11 and 12, to make it
728        possible to check the Perl 5.10 features against Perl 5.10.
729    
730    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
731        pattern matches a fixed length string. PCRE did not allow this; now it
732        does. Neither allows recursion.
733    
734    25. I finally figured out how to implement a request to provide the minimum
735        length of subject string that was needed in order to match a given pattern.
736        (It was back references and recursion that I had previously got hung up
737        on.) This code has now been added to pcre_study(); it finds a lower bound
738        to the length of subject needed. It is not necessarily the greatest lower
739        bound, but using it to avoid searching strings that are too short does give
740        some useful speed-ups. The value is available to calling programs via
741        pcre_fullinfo().
742    
743    26. While implementing 25, I discovered to my embarrassment that pcretest had
744        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
745        study optimizations had never been tested with that matching function.
746        Oops. What is worse, even when it was passed study data, there was a bug in
747        pcre_dfa_exec() that meant it never actually used it. Double oops. There
748        were also very few tests of studied patterns with pcre_dfa_exec().
749    
750    27. If (?| is used to create subpatterns with duplicate numbers, they are now
751        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
752        on the other side of the coin, they are no longer allowed to have different
753        names, because these cannot be distinguished in PCRE, and this has caused
754        confusion. (This is a difference from Perl.)
755    
756    28. When duplicate subpattern names are present (necessarily with different
757        numbers, as required by 27 above), and a test is made by name in a
758        conditional pattern, either for a subpattern having been matched, or for
759        recursion in such a pattern, all the associated numbered subpatterns are
760        tested, and the overall condition is true if the condition is true for any
761        one of them. This is the way Perl works, and is also more like the way
762        testing by number works.
763    
764    
765    Version 7.9 11-Apr-09
766    ---------------------
767    
768    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
769        (pcretest), all targets were linked against these libraries. This included
770        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
771        libraries. This caused unwanted dependencies to be created. This problem
772        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
773        pcretest is linked with readline.
774    
775    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
776        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
777        moved outside it again, because FALSE and TRUE are already defined in AIX,
778        but BOOL is not.
779    
780    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
781        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
782    
783    4.  The pcregrep documentation said spaces were inserted as well as colons (or
784        hyphens) following file names and line numbers when outputting matching
785        lines. This is not true; no spaces are inserted. I have also clarified the
786        wording for the --colour (or --color) option.
787    
788    5.  In pcregrep, when --colour was used with -o, the list of matching strings
789        was not coloured; this is different to GNU grep, so I have changed it to be
790        the same.
791    
792    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
793        each matching line was coloured. Now it goes on to look for further matches
794        of any of the test patterns, which is the same behaviour as GNU grep.
795    
796    7.  A pattern that could match an empty string could cause pcregrep to loop; it
797        doesn't make sense to accept an empty string match in pcregrep, so I have
798        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
799        seems to be how GNU grep behaves.
800    
801    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
802        start or after a newline", because the conditional assertion was not being
803        correctly handled. The rule now is that both the assertion and what follows
804        in the first alternative must satisfy the test.
805    
806    9.  If auto-callout was enabled in a pattern with a conditional group whose
807        condition was an assertion, PCRE could crash during matching, both with
808        pcre_exec() and pcre_dfa_exec().
809    
810    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
811        used for matching.
812    
813    11. Unicode property support in character classes was not working for
814        characters (bytes) greater than 127 when not in UTF-8 mode.
815    
816    12. Added the -M command line option to pcretest.
817    
818    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
819    
820    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
821    
822    16. Added comments and documentation about mis-use of no_arg in the C++
823        wrapper.
824    
825    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
826        from Martin Jerabek that uses macro names for all relevant character and
827        string constants.
828    
829    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
830        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
831        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
832        these, but not everybody uses configure.
833    
834    19. A conditional group that had only one branch was not being correctly
835        recognized as an item that could match an empty string. This meant that an
836        enclosing group might also not be so recognized, causing infinite looping
837        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
838        with the subject "ab", where knowledge that the repeated group can match
839        nothing is needed in order to break the loop.
840    
841    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
842        exec(), but without supplying a callout function, matching went wrong.
843    
844    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
845        leak if the size of the offset vector was greater than 30. When the vector
846        is smaller, the saved offsets during recursion go onto a local stack
847        vector, but for larger vectors malloc() is used. It was failing to free
848        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
849        error, in fact).
850    
851    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
852        heapframe that is used only when UTF-8 support is enabled. This caused no
853        problem, but was untidy.
854    
855    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
856        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
857        included within another project.
858    
859    24. Steven Van Ingelgem's patches to add more options to the CMake support,
860        slightly modified by me:
861    
862          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
863              not building pcregrep.
864    
865          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
866              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
867    
868    25. Forward references, both numeric and by name, in patterns that made use of
869        duplicate group numbers, could behave incorrectly or give incorrect errors,
870        because when scanning forward to find the reference group, PCRE was not
871        taking into account the duplicate group numbers. A pattern such as
872        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
873    
874    26. Changed a few more instances of "const unsigned char *" to USPTR, making
875        the feature of a custom pointer more persuasive (as requested by a user).
876    
877    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
878        pcretest.c, inside #ifndefs, because it seems they are sometimes already
879        pre-defined.
880    
881    28. Added support for (*UTF8) at the start of a pattern.
882    
883    29. Arrange for flags added by the "release type" setting in CMake to be shown
884        in the configuration summary.
885    
886    
887    Version 7.8 05-Sep-08
888    ---------------------
889    
890    1.  Replaced UCP searching code with optimized version as implemented for Ad
891        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
892        stage table and inline lookup instead of a function, giving speed ups of 2
893        to 5 times on some simple patterns that I tested. Permission was given to
894        distribute the MultiStage2.py script that generates the tables (it's not in
895        the tarball, but is in the Subversion repository).
896    
897    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
898        scripts.
899    
900    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
901        a group with a zero qualifier. The result of the study could be incorrect,
902        or the function might crash, depending on the pattern.
903    
904    4.  Caseless matching was not working for non-ASCII characters in back
905        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
906        It now works when Unicode Property Support is available.
907    
908    5.  In pcretest, an escape such as \x{de} in the data was always generating
909        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
910        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
911        truncation.
912    
913    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
914    
915    7.  Added two (int) casts to pcregrep when printing the difference of two
916        pointers, in case they are 64-bit values.
917    
918    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
919        test 2 if it fails.
920    
921    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
922        and a #define of that name to empty if it is not externally set. This is to
923        allow users of MSVC to set it if necessary.
924    
925    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
926        the convenience functions in the pcre_get.c source file.
927    
928    11. An option change at the start of a pattern that had top-level alternatives
929        could cause overwriting and/or a crash. This command provoked a crash in
930        some environments:
931    
932          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
933    
934        This potential security problem was recorded as CVE-2008-2371.
935    
936    12. For a pattern where the match had to start at the beginning or immediately
937        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
938        pcre_dfa_exec() could read past the end of the passed subject if there was
939        no match. To help with detecting such bugs (e.g. with valgrind), I modified
940        pcretest so that it places the subject at the end of its malloc-ed buffer.
941    
942    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
943        exec() might read past the end of the data buffer in UTF-8 mode.
944    
945    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
946        the data contained the byte 0x85 as part of a UTF-8 character within its
947        first line. This applied both to normal and DFA matching.
948    
949    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
950        /^[^d]*?$/8 failed to match "abc".
951    
952    16. Added a missing copyright notice to pcrecpp_internal.h.
953    
954    17. Make it more clear in the documentation that values returned from
955        pcre_exec() in ovector are byte offsets, not character counts.
956    
957    18. Tidied a few places to stop certain compilers from issuing warnings.
958    
959    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
960        supplied by Stefan Weber. I made a further small update for 7.8 because
961        there is a change of source arrangements: the pcre_searchfuncs.c module is
962        replaced by pcre_ucd.c.
963    
964    
965    Version 7.7 07-May-08
966    ---------------------
967    
968    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
969        a string to a long long, pretend we don't even have a long long." This is
970        done by checking for the strtoq, strtoll, and _strtoi64 functions.
971    
972    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
973        pre-7.6 versions, which defined a global no_arg variable instead of putting
974        it in the RE class. (See also #8 below.)
975    
976    3.  Remove a line of dead code, identified by coverity and reported by Nuno
977        Lopes.
978    
979    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
980    
981        (1) The include/exclude patterns were being applied to the whole pathnames
982            of files, instead of just to the final components.
983    
984        (2) If there was more than one level of directory, the subdirectories were
985            skipped unless they satisfied the include/exclude conditions. This is
986            inconsistent with GNU grep (and could even be seen as contrary to the
987            pcregrep specification - which I improved to make it absolutely clear).
988            The action now is always to scan all levels of directory, and just
989            apply the include/exclude patterns to regular files.
990    
991    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
992        --exclude_dir in the tests to avoid scanning .svn directories.
993    
994    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
995        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
996        doesn't support NULs in patterns.
997    
998    7.  Added some missing "const"s to declarations of static tables in
999        pcre_compile.c and pcre_dfa_exec.c.
1000    
1001    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1002        caused by fix #2  above. (Subsequently also a second patch to fix the
1003        first patch. And a third patch - this was a messy problem.)
1004    
1005    9.  Applied Craig's patch to remove the use of push_back().
1006    
1007    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1008        matching function regexec().
1009    
1010    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1011        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1012        references. PCRE supports relative numbers with this syntax (I don't think
1013        Oniguruma does).
1014    
1015    12. Previously, a group with a zero repeat such as (...){0} was completely
1016        omitted from the compiled regex. However, this means that if the group
1017        was called as a subroutine from elsewhere in the pattern, things went wrong
1018        (an internal error was given). Such groups are now left in the compiled
1019        pattern, with a new opcode that causes them to be skipped at execution
1020        time.
1021    
1022    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1023        to the way PCRE behaves:
1024    
1025        (a) A lone ] character is dis-allowed (Perl treats it as data).
1026    
1027        (b) A back reference to an unmatched subpattern matches an empty string
1028            (Perl fails the current match path).
1029    
1030        (c) A data ] in a character class must be notated as \] because if the
1031            first data character in a class is ], it defines an empty class. (In
1032            Perl it is not possible to have an empty class.) The empty class []
1033            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1034            The negative empty class [^] matches any one character, independently
1035            of the DOTALL setting.
1036    
1037    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1038        non-existent subpattern following a character class starting with ']' and
1039        containing () gave an internal compiling error instead of "reference to
1040        non-existent subpattern". Fortunately, when the pattern did exist, the
1041        compiled code was correct. (When scanning forwards to check for the
1042        existencd of the subpattern, it was treating the data ']' as terminating
1043        the class, so got the count wrong. When actually compiling, the reference
1044        was subsequently set up correctly.)
1045    
1046    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1047        it was being rejected as not supported by pcre_dfa_exec(), even though
1048        other assertions are supported. I have made pcre_dfa_exec() support
1049        (*FAIL).
1050    
1051    16. The implementation of 13c above involved the invention of a new opcode,
1052        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1053        cannot be changed at match time, I realized I could make a small
1054        improvement to matching performance by compiling OP_ALLANY instead of
1055        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1056        on the OP_ANY path.
1057    
1058    17. Compiling pcretest on Windows with readline support failed without the
1059        following two fixes: (1) Make the unistd.h include conditional on
1060        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1061    
1062    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1063        ncurses library to be included for pcretest when ReadLine support is
1064        requested, but also to allow for it to be overridden. This patch came from
1065        Daniel Bergström.
1066    
1067    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1068        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1069        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1070        spotting this.
1071    
1072    
1073    Version 7.6 28-Jan-08
1074    ---------------------
1075    
1076    1.  A character class containing a very large number of characters with
1077        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1078        overflow.
1079    
1080    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1081        HAVE_LONG_LONG is not defined.
1082    
1083    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1084        bring them up to date and include new features. This patch includes:
1085    
1086        - Fixed PH's badly added libz and libbz2 support.
1087        - Fixed a problem with static linking.
1088        - Added pcredemo. [But later removed - see 7 below.]
1089        - Fixed dftables problem and added an option.
1090        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1091            HAVE_LONG_LONG.
1092        - Added readline support for pcretest.
1093        - Added an listing of the option settings after cmake has run.
1094    
1095    4.  A user submitted a patch to Makefile that makes it easy to create
1096        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1097        Makefile.am that cause it to include this special target, without
1098        affecting anything else. Note that the same mingw target plus all
1099        the other distribution libraries and programs are now supported
1100        when configuring with CMake (see 6 below) instead of with
1101        Configure/Make.
1102    
1103    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1104        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1105        exported in the Windows port". It has not yet been confirmed that the patch
1106        solves the problem, but it does no harm.
1107    
1108    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1109        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1110        with CMake, and also correct the comment about stack recursion.
1111    
1112    7.  Remove the automatic building of pcredemo from the ./configure system and
1113        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1114        of a program that users should build themselves after PCRE is installed, so
1115        building it automatically is not really right. What is more, it gave
1116        trouble in some build environments.
1117    
1118    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1119    
1120    
1121    Version 7.5 10-Jan-08
1122    ---------------------
1123    
1124    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1125        values in parens when parsing an RE using the C++ wrapper."
1126    
1127    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1128        Characters greater than 255 were excluded from the class instead of being
1129        included.
1130    
1131    3.  The same bug as (2) above applied to negated POSIX classes such as
1132        [:^space:].
1133    
1134    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1135        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1136        I have changed it.
1137    
1138    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1139        first named subpattern) and a construct such as (?&a) would reference the
1140        first named subpattern whose name started with "a" (in other words, the
1141        length check was missing). Both these problems are fixed. "Subpattern name
1142        expected" is now given for (?&) (a zero-length name), and this patch also
1143        makes it give the same error for \k'' (previously it complained that that
1144        was a reference to a non-existent subpattern).
1145    
1146    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1147        this is right because (?- can be followed by option settings as well as by
1148        digits. I have, however, made the messages clearer.
1149    
1150    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1151        than the number used in the conditional) now cause a compile-time error.
1152        This is actually not compatible with Perl, which accepts such patterns, but
1153        treats the conditional as always being FALSE (as PCRE used to), but it
1154        seems to me that giving a diagnostic is better.
1155    
1156    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1157        and messages.
1158    
1159    9.  Fix two occurrences of "backslash" in comments that should have been
1160        "backspace".
1161    
1162    10. Remove two redundant lines of code that can never be obeyed (their function
1163        was moved elsewhere).
1164    
1165    11. The program that makes PCRE's Unicode character property table had a bug
1166        which caused it to generate incorrect table entries for sequences of
1167        characters that have the same character type, but are in different scripts.
1168        It amalgamated them into a single range, with the script of the first of
1169        them. In other words, some characters were in the wrong script. There were
1170        thirteen such cases, affecting characters in the following ranges:
1171    
1172          U+002b0 - U+002c1
1173          U+0060c - U+0060d
1174          U+0061e - U+00612
1175          U+0064b - U+0065e
1176          U+0074d - U+0076d
1177          U+01800 - U+01805
1178          U+01d00 - U+01d77
1179          U+01d9b - U+01dbf
1180          U+0200b - U+0200f
1181          U+030fc - U+030fe
1182          U+03260 - U+0327f
1183          U+0fb46 - U+0fbb1
1184          U+10450 - U+1049d
1185    
1186    12. The -o option (show only the matching part of a line) for pcregrep was not
1187        compatible with GNU grep in that, if there was more than one match in a
1188        line, it showed only the first of them. It now behaves in the same way as
1189        GNU grep.
1190    
1191    13. If the -o and -v options were combined for pcregrep, it printed a blank
1192        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1193        does the same. The return code can be used to tell if there were any
1194        non-matching lines.
1195    
1196    14. Added --file-offsets and --line-offsets to pcregrep.
1197    
1198    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1199        infinitely looping recursion. The bug was that positive lookaheads were not
1200        being skipped when checking for a possible empty match (negative lookaheads
1201        and both kinds of lookbehind were skipped).
1202    
1203    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1204        inclusion of <windows.h> to before rather than after the definition of
1205        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1206    
1207    17. Specifying a possessive quantifier with a specific limit for a Unicode
1208        character property caused pcre_compile() to compile bad code, which led at
1209        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1210        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1211        caused the error; without that there was no problem.
1212    
1213    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1214    
1215    19. Added --enable-pcretest-libreadline.
1216    
1217    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1218        RE::GlobalReplace(). As a result, the number of replacements returned was
1219        double what it should be. I removed one of the increments, but Craig sent a
1220        later patch that removed the other one (the right fix) and added unit tests
1221        that check the return values (which was not done before).
1222    
1223    21. Several CMake things:
1224    
1225        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1226            the names libpcre and libpcreposix, not just pcre and pcreposix.
1227    
1228        (2) The above change means that pcretest and pcregrep are now correctly
1229            linked with the newly-built libraries, not previously installed ones.
1230    
1231        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1232    
1233    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1234        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1235        UTF-8 newline character). The key issue is that the pattern starts .*;
1236        this means that the match must be either at the beginning, or after a
1237        newline. The bug was in the code for advancing after a failed match and
1238        checking that the new position followed a newline. It was not taking
1239        account of UTF-8 characters correctly.
1240    
1241    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1242        character classes. PCRE was not treating the sequence [:...:] as a
1243        character class unless the ... were all letters. Perl, however, seems to
1244        allow any characters between [: and :], though of course it rejects as
1245        unknown any "names" that contain non-letters, because all the known class
1246        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1247        for example, whereas PCRE did not - it did not recognize a POSIX character
1248        class. This seemed a bit dangerous, so the code has been changed to be
1249        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1250        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1251        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1252        Perl does, and where it didn't before.
1253    
1254    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1255        Windows environments %n is disabled by default.
1256    
1257    
1258    Version 7.4 21-Sep-07
1259    ---------------------
1260    
1261    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1262        means that a class such as [\s] counted as "explicit reference to CR or
1263        LF". That isn't really right - the whole point of the change was to try to
1264        help when there was an actual mention of one of the two characters. So now
1265        the change happens only if \r or \n (or a literal CR or LF) character is
1266        encountered.
1267    
1268    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1269        of both had grown to the point where there were only 3 bits left.
1270        Fortunately, there was spare space in the data structure, and so I have
1271        moved the internal flags into a new 16-bit field to free up more option
1272        bits.
1273    
1274    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1275        but did not set the internal JCHANGED flag - either of these is enough to
1276        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1277        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1278        start sets both bits.
1279    
1280    4.  Added options (at build time, compile time, exec time) to change \R from
1281        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1282    
1283    5.  doc/pcresyntax.html was missing from the distribution.
1284    
1285    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1286        compatibility, even though it is no longer used.
1287    
1288    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1289        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1290        windows.h file is present (where different names are used). [This was
1291        reversed later after testing - see 16 below.]
1292    
1293    8.  Changed all #include <config.h> to #include "config.h". There were also
1294        some further <pcre.h> cases that I changed to "pcre.h".
1295    
1296    9.  When pcregrep was used with the --colour option, it missed the line ending
1297        sequence off the lines that it output.
1298    
1299    10. It was pointed out to me that arrays of string pointers cause lots of
1300        relocations when a shared library is dynamically loaded. A technique of
1301        using a single long string with a table of offsets can drastically reduce
1302        these. I have refactored PCRE in four places to do this. The result is
1303        dramatic:
1304    
1305          Originally:                          290
1306          After changing UCP table:            187
1307          After changing error message table:   43
1308          After changing table of "verbs"       36
1309          After changing table of Posix names   22
1310    
1311        Thanks to the folks working on Gregex for glib for this insight.
1312    
1313    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1314        unicode-properties was also set.
1315    
1316    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1317    
1318    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1319        checked only for CRLF.
1320    
1321    14. Added casts to pcretest.c to avoid compiler warnings.
1322    
1323    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1324    
1325    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1326        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1327        entirely. This removes changes made in 7 above.
1328    
1329    17. The CMake files have been updated, and there is now more information about
1330        building with CMake in the NON-UNIX-USE document.
1331    
1332    
1333    Version 7.3 28-Aug-07
1334    ---------------------
1335    
1336     1. In the rejigging of the build system that eventually resulted in 7.1, the
1337        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1338        brackets there is not right, since it causes compilers to look for an
1339        installed pcre.h, not the version that is in the source that is being
1340        compiled (which of course may be different). I have changed it back to:
1341    
1342          #include "pcre.h"
1343    
1344        I have a vague recollection that the change was concerned with compiling in
1345        different directories, but in the new build system, that is taken care of
1346        by the VPATH setting the Makefile.
1347    
1348     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1349        when the subject happened to end in the byte 0x85 (e.g. if the last
1350        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1351        characters but of course it shouldn't be taken as a newline when it is part
1352        of another character. The bug was that, for an unlimited repeat of . in
1353        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1354        characters when looking for a newline.
1355    
1356     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1357    
1358     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1359        in debug output.
1360    
1361     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1362        long printing in the pcrecpp unittest when running under MinGW.
1363    
1364     6. ESC_K was left out of the EBCDIC table.
1365    
1366     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1367        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1368        limit also applies to "virtual nesting" when a pattern is recursive, and in
1369        this case 1000 isn't so big. I have been able to remove this limit at the
1370        expense of backing off one optimization in certain circumstances. Normally,
1371        when pcre_exec() would call its internal match() function recursively and
1372        immediately return the result unconditionally, it uses a "tail recursion"
1373        feature to save stack. However, when a subpattern that can match an empty
1374        string has an unlimited repetition quantifier, it no longer makes this
1375        optimization. That gives it a stack frame in which to save the data for
1376        checking that an empty string has been matched. Previously this was taken
1377        from the 1000-entry workspace that had been reserved. So now there is no
1378        explicit limit, but more stack is used.
1379    
1380     8. Applied Daniel's patches to solve problems with the import/export magic
1381        syntax that is required for Windows, and which was going wrong for the
1382        pcreposix and pcrecpp parts of the library. These were overlooked when this
1383        problem was solved for the main library.
1384    
1385     9. There were some crude static tests to avoid integer overflow when computing
1386        the size of patterns that contain repeated groups with explicit upper
1387        limits. As the maximum quantifier is 65535, the maximum group length was
1388        set at 30,000 so that the product of these two numbers did not overflow a
1389        32-bit integer. However, it turns out that people want to use groups that
1390        are longer than 30,000 bytes (though not repeat them that many times).
1391        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1392        made it possible to implement the integer overflow checks in a much more
1393        dynamic way, which I have now done. The artificial limitation on group
1394        length has been removed - we now have only the limit on the total length of
1395        the compiled pattern, which depends on the LINK_SIZE setting.
1396    
1397    10. Fixed a bug in the documentation for get/copy named substring when
1398        duplicate names are permitted. If none of the named substrings are set, the
1399        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1400        empty string.
1401    
1402    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1403        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1404        because the ] is interpreted as the first data character and the
1405        terminating ] is not found. PCRE has been made compatible with Perl in this
1406        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1407        cause memory overwriting.
1408    
1409    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1410        string has been matched (to stop an infinite loop). It was not recognizing
1411        a conditional subpattern that could match an empty string if that
1412        subpattern was within another subpattern. For example, it looped when
1413        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1414        condition was not nested. This bug has been fixed.
1415    
1416    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1417        past the start of the subject in the presence of bytes with the top bit
1418        set, for example "\x8aBCD".
1419    
1420    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1421        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1422    
1423    14. Optimized (?!) to (*FAIL).
1424    
1425    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1426        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1427        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1428        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1429        does: it's just the validity check that is more restrictive.
1430    
1431    16. Inserted checks for integer overflows during escape sequence (backslash)
1432        processing, and also fixed erroneous offset values for syntax errors during
1433        backslash processing.
1434    
1435    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1436        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1437    
1438    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1439        caused an overrun.
1440    
1441    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1442        something other than just ASCII characters) inside a group that had an
1443        unlimited repeat caused a loop at compile time (while checking to see
1444        whether the group could match an empty string).
1445    
1446    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1447        [\P{Any}] did so. (Error in the code for printing property names.)
1448    
1449    21. An orphan \E inside a character class could cause a crash.
1450    
1451    22. A repeated capturing bracket such as (A)? could cause a wild memory
1452        reference during compilation.
1453    
1454    23. There are several functions in pcre_compile() that scan along a compiled
1455        expression for various reasons (e.g. to see if it's fixed length for look
1456        behind). There were bugs in these functions when a repeated \p or \P was
1457        present in the pattern. These operators have additional parameters compared
1458        with \d, etc, and these were not being taken into account when moving along
1459        the compiled data. Specifically:
1460    
1461        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1462            length.
1463    
1464        (b) An item such as \pL+ within a repeated group could cause crashes or
1465            loops.
1466    
1467        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1468            "reference to non-existent subpattern" error.
1469    
1470        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1471    
1472    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1473        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1474    
1475    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1476    
1477    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1478        character were causing crashes (broken optimization).
1479    
1480    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1481        \p or \P) caused a compile-time loop.
1482    
1483    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1484        break. For example, the unstudied pattern [\r\n]A does not match the string
1485        "\r\nA" because change 7.0/46 below moves the current point on by two
1486        characters after failing to match at the start. However, the pattern \nA
1487        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1488        the same is true. There doesn't seem any very clean way out of this, but
1489        what I have chosen to do makes the common cases work: PCRE now takes note
1490        of whether there can be an explicit match for \r or \n anywhere in the
1491        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1492        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1493        pattern has explicit CR or LF references.
1494    
1495    29. Added (*CR) etc for changing newline setting at start of pattern.
1496    
1497    
1498    Version 7.2 19-Jun-07
1499  ---------------------  ---------------------
1500    
1501   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 21  Version 7.2 01-May-07 Line 1515  Version 7.2 01-May-07
1515      stack recursion. This gives a massive performance boost under BSD, but just      stack recursion. This gives a massive performance boost under BSD, but just
1516      a small improvement under Linux. However, it saves one field in the frame      a small improvement under Linux. However, it saves one field in the frame
1517      in all cases.      in all cases.
1518    
1519   6. Added more features from the forthcoming Perl 5.10:   6. Added more features from the forthcoming Perl 5.10:
1520    
1521      (a) (?-n) (where n is a string of digits) is a relative subroutine or      (a) (?-n) (where n is a string of digits) is a relative subroutine or
1522          recursion call. It refers to the nth most recently opened parentheses.          recursion call. It refers to the nth most recently opened parentheses.
1523    
1524      (b) (?+n) is also a relative subroutine call; it refers to the nth next      (b) (?+n) is also a relative subroutine call; it refers to the nth next
1525          to be opened parentheses.          to be opened parentheses.
1526    
1527      (c) Conditions that refer to capturing parentheses can be specified      (c) Conditions that refer to capturing parentheses can be specified
1528          relatively, for example, (?(-2)... or (?(+3)...          relatively, for example, (?(-2)... or (?(+3)...
1529    
1530      (d) \K resets the start of the current match so that everything before      (d) \K resets the start of the current match so that everything before
1531          is not part of it.          is not part of it.
1532    
1533   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and      (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1534      PCRE_INFO_JCHANGED.  
1535        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1536   8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not          reference syntax.
1537      terminating or by crashing. Diagnosed by Viktor Griph; it was in the code  
1538        (g) (?| introduces a group in which the numbering of parentheses in each
1539            alternative starts with the same number.
1540    
1541        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1542    
1543     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1544        PCRE_INFO_JCHANGED.
1545    
1546     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1547        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1548      for detecting groups that can match an empty string.      for detecting groups that can match an empty string.
1549    
1550     9. A pattern with a very large number of alternatives (more than several
1551        hundred) was running out of internal workspace during the pre-compile
1552        phase, where pcre_compile() figures out how much memory will be needed. A
1553        bit of new cunning has reduced the workspace needed for groups with
1554        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1555        workspace instead of running out of the 4096 that are available.
1556    
1557    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1558    
1559    11. Applied patch from Google to remove an optimization that didn't quite work.
1560        The report of the bug said:
1561    
1562          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1563          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1564          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1565    
1566    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1567        it matched the wrong number of bytes.
1568    
1569    
1570  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
1571  ---------------------  ---------------------

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