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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-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    26. Updated RunTest.bat in the distribution to the version supplied by Tom
149        Fortmann. This supports explicit test numbers on the command line, and has
150        argument validation and error reporting.
151    
152    
153    
154    Version 8.12 15-Jan-2011
155    ------------------------
156    
157    1.  Fixed some typos in the markup of the man pages, and wrote a script that
158        checks for such things as part of the documentation building process.
159    
160    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
161        --match-limit and --recursion-limit options (added for 8.11). In
162        particular, this made one of the standard tests fail. (The integer value
163        went into the wrong half of a long int.)
164    
165    3.  If the --colour option was given to pcregrep with -v (invert match), it
166        did strange things, either producing crazy output, or crashing. It should,
167        of course, ignore a request for colour when reporting lines that do not
168        match.
169    
170    4.  Another pcregrep bug caused similar problems if --colour was specified with
171        -M (multiline) and the pattern match finished with a line ending.
172    
173    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
174        matched in multiline mode, the following line was shown as part of the
175        match. This seems wrong, so I have changed it.
176    
177    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
178        the check for further matches in the same line (so they could be coloured)
179        to overrun the end of the current line. If another match was found, it was
180        incorrectly shown (and then shown again when found in the next line).
181    
182    7.  If pcregrep was compiled under Windows, there was a reference to the
183        function pcregrep_exit() before it was defined. I am assuming this was
184        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
185        reported by a user. I've moved the definition above the reference.
186    
187    
188    Version 8.11 10-Dec-2010
189    ------------------------
190    
191    1.  (*THEN) was not working properly if there were untried alternatives prior
192        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
193        backtracked to try for "b" instead of moving to the next alternative branch
194        at the same level (in this case, to look for "c"). The Perl documentation
195        is clear that when (*THEN) is backtracked onto, it goes to the "next
196        alternative in the innermost enclosing group".
197    
198    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
199        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
200        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
201        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
202        (*THEN).
203    
204    3.  If \s appeared in a character class, it removed the VT character from
205        the class, even if it had been included by some previous item, for example
206        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
207        of \s, but is part of the POSIX "space" class.)
208    
209    4.  A partial match never returns an empty string (because you can always
210        match an empty string at the end of the subject); however the checking for
211        an empty string was starting at the "start of match" point. This has been
212        changed to the "earliest inspected character" point, because the returned
213        data for a partial match starts at this character. This means that, for
214        example, /(?<=abc)def/ gives a partial match for the subject "abc"
215        (previously it gave "no match").
216    
217    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
218        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
219        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
220        has an implication that the given string is incomplete (because a partial
221        match is preferred over a full match). For this reason, these items now
222        give a partial match in this situation. [Aside: previously, the one case
223        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
224        match rather than a full match, which was wrong by the old rules, but is
225        now correct.]
226    
227    6.  There was a bug in the handling of #-introduced comments, recognized when
228        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
229        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
230        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
231        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
232        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
233        places in pcre_compile().
234    
235    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
236        comments when looking ahead for named forward references to subpatterns,
237        the only newline sequence it recognized was NL. It now handles newlines
238        according to the set newline convention.
239    
240    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
241        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
242        cater for a lack of strerror(). These oversights have been fixed.
243    
244    9.  Added --match-limit and --recursion-limit to pcregrep.
245    
246    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
247    
248    11. When the -o option was used, pcregrep was setting a return code of 1, even
249        when matches were found, and --line-buffered was not being honoured.
250    
251    12. Added an optional parentheses number to the -o and --only-matching options
252        of pcregrep.
253    
254    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
255        can match an empty string. The code to do it in pcretest and pcredemo
256        needed fixing:
257    
258        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
259            only one byte after an empty string match just before CRLF (this case
260            just got forgotten; "any" and "anycrlf" were OK).
261    
262        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
263            mode when an empty string match preceded an ASCII character followed by
264            a non-ASCII character. (The code for advancing by one character rather
265            than one byte was nonsense.)
266    
267        (c) The pcredemo.c sample program did not have any code at all to handle
268            the cases when CRLF is a valid newline sequence.
269    
270    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
271        as a starting offset was within the subject string. There is now a new
272        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
273        negative or greater than the length of the string. In order to test this,
274        pcretest is extended to allow the setting of negative starting offsets.
275    
276    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
277        starting offset points to the beginning of a UTF-8 character was
278        unnecessarily clumsy. I tidied it up.
279    
280    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
281        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
282    
283    17. Nobody had reported that the --include_dir option, which was added in
284        release 7.7 should have been called --include-dir (hyphen, not underscore)
285        for compatibility with GNU grep. I have changed it to --include-dir, but
286        left --include_dir as an undocumented synonym, and the same for
287        --exclude-dir, though that is not available in GNU grep, at least as of
288        release 2.5.4.
289    
290    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
291        characters from a string of bytes) have been redefined so as not to use
292        loops, in order to improve performance in some environments. At the same
293        time, I abstracted some of the common code into auxiliary macros to save
294        repetition (this should not affect the compiled code).
295    
296    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
297        compile-time error is now given if \c is not followed by an ASCII
298        character, that is, a byte less than 128. (In EBCDIC mode, the code is
299        different, and any byte value is allowed.)
300    
301    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
302        START_OPTIMIZE option, which is now allowed at compile time - but just
303        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
304        to pcregrep and other applications that have no direct access to PCRE
305        options. The new /Y option in pcretest sets this option when calling
306        pcre_compile().
307    
308    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
309        back references. Groups containing recursive back references were forced to
310        be atomic by that change, but in the case of named groups, the amount of
311        memory required was incorrectly computed, leading to "Failed: internal
312        error: code overflow". This has been fixed.
313    
314    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
315        pcretest.c, to avoid build problems in some Borland environments.
316    
317    
318    Version 8.10 25-Jun-2010
319    ------------------------
320    
321    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
322        THEN.
323    
324    2.  (*ACCEPT) was not working when inside an atomic group.
325    
326    3.  Inside a character class, \B is treated as a literal by default, but
327        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
328        causes the error). The code is unchanged, but I tidied the documentation.
329    
330    4.  Inside a character class, PCRE always treated \R and \X as literals,
331        whereas Perl faults them if its -w option is set. I have changed PCRE so
332        that it faults them when PCRE_EXTRA is set.
333    
334    5.  Added support for \N, which always matches any character other than
335        newline. (It is the same as "." when PCRE_DOTALL is not set.)
336    
337    6.  When compiling pcregrep with newer versions of gcc which may have
338        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
339        declared with attribute warn_unused_result" were given. Just casting the
340        result to (void) does not stop the warnings; a more elaborate fudge is
341        needed. I've used a macro to implement this.
342    
343    7.  Minor change to pcretest.c to avoid a compiler warning.
344    
345    8.  Added four artifical Unicode properties to help with an option to make
346        \s etc use properties (see next item). The new properties are: Xan
347        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
348    
349    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
350        use Unicode properties. (*UCP) at the start of a pattern can be used to set
351        this option. Modified pcretest to add /W to test this facility. Added
352        REG_UCP to make it available via the POSIX interface.
353    
354    10. Added --line-buffered to pcregrep.
355    
356    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
357        studied, and the match started with a letter with a code point greater than
358        127 whose first byte was different to the first byte of the other case of
359        the letter, the other case of this starting letter was not recognized
360        (#976).
361    
362    12. If a pattern that was studied started with a repeated Unicode property
363        test, for example, \p{Nd}+, there was the theoretical possibility of
364        setting up an incorrect bitmap of starting bytes, but fortunately it could
365        not have actually happened in practice until change 8 above was made (it
366        added property types that matched character-matching opcodes).
367    
368    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
369        possible starting bytes for non-anchored patterns.
370    
371    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
372        \R, and also a number of cases that involve Unicode properties, both
373        explicit and implicit when PCRE_UCP is set.
374    
375    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
376        input, it could crash or give wrong results if characters with values
377        greater than 0xc0 were present in the subject string. (Detail: it assumed
378        UTF-8 input when processing these items.)
379    
380    16. Added a lot of (int) casts to avoid compiler warnings in systems where
381        size_t is 64-bit (#991).
382    
383    17. Added a check for running out of memory when PCRE is compiled with
384        --disable-stack-for-recursion (#990).
385    
386    18. If the last data line in a file for pcretest does not have a newline on
387        the end, a newline was missing in the output.
388    
389    19. The default pcre_chartables.c file recognizes only ASCII characters (values
390        less than 128) in its various bitmaps. However, there is a facility for
391        generating tables according to the current locale when PCRE is compiled. It
392        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
393        characters, are recognized by isspace() and therefore were getting set in
394        these tables, and indeed these tables seem to approximate to ISO 8859. This
395        caused a problem in UTF-8 mode when pcre_study() was used to create a list
396        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
397        which of course cannot start UTF-8 characters. I have changed the code so
398        that only real ASCII characters (less than 128) and the correct starting
399        bytes for UTF-8 encodings are set for characters greater than 127 when in
400        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
401        altogether.)
402    
403    20. Added the /T option to pcretest so as to be able to run tests with non-
404        standard character tables, thus making it possible to include the tests
405        used for 19 above in the standard set of tests.
406    
407    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
408        reference to a subpattern the other side of a comment that contains an
409        opening parenthesis caused either an internal compiling error, or a
410        reference to the wrong subpattern.
411    
412    
413    Version 8.02 19-Mar-2010
414    ------------------------
415    
416    1.  The Unicode data tables have been updated to Unicode 5.2.0.
417    
418    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
419        configured.
420    
421    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
422        original author of that file, following a query about its status.
423    
424    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
425        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
426    
427    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
428        quantifier applied to a forward-referencing subroutine call, could compile
429        incorrect code or give the error "internal error: previously-checked
430        referenced subpattern not found".
431    
432    6.  Both MS Visual Studio and Symbian OS have problems with initializing
433        variables to point to external functions. For these systems, therefore,
434        pcre_malloc etc. are now initialized to local functions that call the
435        relevant global functions.
436    
437    7.  There were two entries missing in the vectors called coptable and poptable
438        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
439        I've fixed the data, and added a kludgy way of testing at compile time that
440        the lengths are correct (equal to the number of opcodes).
441    
442    8.  Following on from 7, I added a similar kludge to check the length of the
443        eint vector in pcreposix.c.
444    
445    9.  Error texts for pcre_compile() are held as one long string to avoid too
446        much relocation at load time. To find a text, the string is searched,
447        counting zeros. There was no check for running off the end of the string,
448        which could happen if a new error number was added without updating the
449        string.
450    
451    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
452    
453    11. \K was not working if it appeared in an atomic group or in a group that
454        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
455        \K is "not well defined" if used in an assertion. PCRE now accepts it if
456        the assertion is positive, but not if it is negative.
457    
458    12. Change 11 fortuitously reduced the size of the stack frame used in the
459        "match()" function of pcre_exec.c by one pointer. Forthcoming
460        implementation of support for (*MARK) will need an extra pointer on the
461        stack; I have reserved it now, so that the stack frame size does not
462        decrease.
463    
464    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
465        item in branch that calls a recursion is a subroutine call - as in the
466        second branch in the above example - was incorrectly given the compile-
467        time error "recursive call could loop indefinitely" because pcre_compile()
468        was not correctly checking the subroutine for matching a non-empty string.
469    
470    14. The checks for overrunning compiling workspace could trigger after an
471        overrun had occurred. This is a "should never occur" error, but it can be
472        triggered by pathological patterns such as hundreds of nested parentheses.
473        The checks now trigger 100 bytes before the end of the workspace.
474    
475    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
476    
477    
478    Version 8.01 19-Jan-2010
479    ------------------------
480    
481    1.  If a pattern contained a conditional subpattern with only one branch (in
482        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
483        computed the wrong minimum data length (which is of course zero for such
484        subpatterns). This could cause incorrect "no match" results.
485    
486    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
487        the pattern is reset in the first branch, pcre_compile() failed with
488        "internal error: code overflow at offset...". This happened only when
489        the reset was to the original external option setting. (An optimization
490        abstracts leading options settings into an external setting, which was the
491        cause of this.)
492    
493    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
494        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
495        assertion pattern did not match (meaning that the assertion was true), it
496        was incorrectly treated as false if the SKIP had been reached during the
497        matching. This also applied to assertions used as conditions.
498    
499    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
500        assertion subpattern, including such a pattern used as a condition,
501        unpredictable results occurred, instead of the error return
502        PCRE_ERROR_DFA_UITEM.
503    
504    5.  The C++ GlobalReplace function was not working like Perl for the special
505        situation when an empty string is matched. It now does the fancy magic
506        stuff that is necessary.
507    
508    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
509        removed. (These were left over from very, very early versions of PCRE.)
510    
511    7.  Some cosmetic changes to the code to make life easier when compiling it
512        as part of something else:
513    
514        (a) Change DEBUG to PCRE_DEBUG.
515    
516        (b) In pcre_compile(), rename the member of the "branch_chain" structure
517            called "current" as "current_branch", to prevent a collision with the
518            Linux macro when compiled as a kernel module.
519    
520        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
521            prevent a collision with the Linux macro when compiled as a kernel
522            module.
523    
524    8.  In pcre_compile() there are some checks for integer overflows that used to
525        cast potentially large values to (double). This has been changed to that
526        when building, a check for int64_t is made, and if it is found, it is used
527        instead, thus avoiding the use of floating point arithmetic. (There is no
528        other use of FP in PCRE.) If int64_t is not found, the fallback is to
529        double.
530    
531    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
532        2005 (difference between two addresses compared to an unsigned value).
533    
534    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
535        custom one, because of the following reported problem in Windows:
536    
537          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
538              under Win32.
539          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
540              therefore missing the function definition.
541          - The compiler thus generates a "C" signature for the test function.
542          - The linker fails to find the "C" function.
543          - PCRE fails to configure if asked to do so against libbz2.
544    
545    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
546        messages were output:
547    
548          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
549          rerunning libtoolize, to keep the correct libtool macros in-tree.
550          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
551    
552        I have done both of these things.
553    
554    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
555        most of the time, it *can* run out if it is given a pattern that contains a
556        runaway infinite recursion. I updated the discussion in the pcrestack man
557        page.
558    
559    13. Now that we have gone to the x.xx style of version numbers, the minor
560        version may start with zero. Using 08 or 09 is a bad idea because users
561        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
562        interpreted as invalid octal numbers. I've updated the previous comment in
563        configure.ac, and also added a check that gives an error if 08 or 09 are
564        used.
565    
566    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
567        causing partial matching to fail when the end of the subject matched \W
568        in a UTF-8 pattern where \W was quantified with a minimum of 3.
569    
570    15. There were some discrepancies between the declarations in pcre_internal.h
571        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
572        their definitions. The declarations used "const uschar *" and the
573        definitions used USPTR. Even though USPTR is normally defined as "const
574        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
575        reported that: "This difference in casting confuses some C++ compilers, for
576        example, SunCC recognizes above declarations as different functions and
577        generates broken code for hbpcre." I have changed the declarations to use
578        USPTR.
579    
580    16. GNU libtool is named differently on some systems. The autogen.sh script now
581        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
582        (FreeBSD).
583    
584    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
585        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
586        comment: "Figure out how to create a longlong from a string: strtoll and
587        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
588        instance, but it only takes 2 args instead of 3!"
589    
590    18. A subtle bug concerned with back references has been fixed by a change of
591        specification, with a corresponding code fix. A pattern such as
592        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
593        refers, was giving matches when it shouldn't. For example, xa=xaaa would
594        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
595        same bug. Such groups have to be quantified to be useful, or contained
596        inside another quantified group. (If there's no repetition, the reference
597        can never match.) The problem arises because, having left the group and
598        moved on to the rest of the pattern, a later failure that backtracks into
599        the group uses the captured value from the final iteration of the group
600        rather than the correct earlier one. I have fixed this in PCRE by forcing
601        any group that contains a reference to itself to be an atomic group; that
602        is, there cannot be any backtracking into it once it has completed. This is
603        similar to recursive and subroutine calls.
604    
605    
606    Version 8.00 19-Oct-09
607    ----------------------
608    
609    1.  The table for translating pcre_compile() error codes into POSIX error codes
610        was out-of-date, and there was no check on the pcre_compile() error code
611        being within the table. This could lead to an OK return being given in
612        error.
613    
614    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
615        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
616        in a Windows environment.
617    
618    3.  The pcregrep --count option prints the count for each file even when it is
619        zero, as does GNU grep. However, pcregrep was also printing all files when
620        --files-with-matches was added. Now, when both options are given, it prints
621        counts only for those files that have at least one match. (GNU grep just
622        prints the file name in this circumstance, but including the count seems
623        more useful - otherwise, why use --count?) Also ensured that the
624        combination -clh just lists non-zero counts, with no names.
625    
626    4.  The long form of the pcregrep -F option was incorrectly implemented as
627        --fixed_strings instead of --fixed-strings. This is an incompatible change,
628        but it seems right to fix it, and I didn't think it was worth preserving
629        the old behaviour.
630    
631    5.  The command line items --regex=pattern and --regexp=pattern were not
632        recognized by pcregrep, which required --regex pattern or --regexp pattern
633        (with a space rather than an '='). The man page documented the '=' forms,
634        which are compatible with GNU grep; these now work.
635    
636    6.  No libpcreposix.pc file was created for pkg-config; there was just
637        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
638    
639    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
640        when UCP support is not needed, by modifying the Python script that
641        generates it from Unicode data files. This should not matter if the module
642        is correctly used as a library, but I received one complaint about 50K of
643        unwanted data. My guess is that the person linked everything into his
644        program rather than using a library. Anyway, it does no harm.
645    
646    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
647        was a minimum greater than 1 for a wide character in a possessive
648        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
649        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
650        character. Chaos in the form of incorrect output or a compiling loop could
651        result.
652    
653    9.  The restrictions on what a pattern can contain when partial matching is
654        requested for pcre_exec() have been removed. All patterns can now be
655        partially matched by this function. In addition, if there are at least two
656        slots in the offset vector, the offset of the earliest inspected character
657        for the match and the offset of the end of the subject are set in them when
658        PCRE_ERROR_PARTIAL is returned.
659    
660    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
661        synonymous with PCRE_PARTIAL, for backwards compatibility, and
662        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
663        and may be more useful for multi-segment matching.
664    
665    11. Partial matching with pcre_exec() is now more intuitive. A partial match
666        used to be given if ever the end of the subject was reached; now it is
667        given only if matching could not proceed because another character was
668        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
669        string "Z", which now yields "no match" instead of "partial match". In the
670        case of pcre_dfa_exec(), "no match" is given if every matching path for the
671        final character ended with (*FAIL).
672    
673    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
674        if the pattern had a "must contain" character that was already found in the
675        earlier partial match, unless partial matching was again requested. For
676        example, with the pattern /dog.(body)?/, the "must contain" character is
677        "g". If the first part-match was for the string "dog", restarting with
678        "sbody" failed. This bug has been fixed.
679    
680    13. The string returned by pcre_dfa_exec() after a partial match has been
681        changed so that it starts at the first inspected character rather than the
682        first character of the match. This makes a difference only if the pattern
683        starts with a lookbehind assertion or \b or \B (\K is not supported by
684        pcre_dfa_exec()). It's an incompatible change, but it makes the two
685        matching functions compatible, and I think it's the right thing to do.
686    
687    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
688        so that the demonstration program is easily available in environments where
689        PCRE has not been installed from source.
690    
691    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
692        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
693        library.
694    
695    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
696        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
697        is not the first non-POSIX option to be added. Clearly some people find
698        these options useful.
699    
700    17. If a caller to the POSIX matching function regexec() passes a non-zero
701        value for nmatch with a NULL value for pmatch, the value of
702        nmatch is forced to zero.
703    
704    18. RunGrepTest did not have a test for the availability of the -u option of
705        the diff command, as RunTest does. It now checks in the same way as
706        RunTest, and also checks for the -b option.
707    
708    19. If an odd number of negated classes containing just a single character
709        interposed, within parentheses, between a forward reference to a named
710        subpattern and the definition of the subpattern, compilation crashed with
711        an internal error, complaining that it could not find the referenced
712        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
713        [The bug was that it was starting one character too far in when skipping
714        over the character class, thus treating the ] as data rather than
715        terminating the class. This meant it could skip too much.]
716    
717    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
718        /g option in pcretest when the pattern contains \K, which makes it possible
719        to have an empty string match not at the start, even when the pattern is
720        anchored. Updated pcretest and pcredemo to use this option.
721    
722    21. If the maximum number of capturing subpatterns in a recursion was greater
723        than the maximum at the outer level, the higher number was returned, but
724        with unset values at the outer level. The correct (outer level) value is
725        now given.
726    
727    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
728        PCRE did not set those parentheses (unlike Perl). I have now found a way to
729        make it do so. The string so far is captured, making this feature
730        compatible with Perl.
731    
732    23. The tests have been re-organized, adding tests 11 and 12, to make it
733        possible to check the Perl 5.10 features against Perl 5.10.
734    
735    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
736        pattern matches a fixed length string. PCRE did not allow this; now it
737        does. Neither allows recursion.
738    
739    25. I finally figured out how to implement a request to provide the minimum
740        length of subject string that was needed in order to match a given pattern.
741        (It was back references and recursion that I had previously got hung up
742        on.) This code has now been added to pcre_study(); it finds a lower bound
743        to the length of subject needed. It is not necessarily the greatest lower
744        bound, but using it to avoid searching strings that are too short does give
745        some useful speed-ups. The value is available to calling programs via
746        pcre_fullinfo().
747    
748    26. While implementing 25, I discovered to my embarrassment that pcretest had
749        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
750        study optimizations had never been tested with that matching function.
751        Oops. What is worse, even when it was passed study data, there was a bug in
752        pcre_dfa_exec() that meant it never actually used it. Double oops. There
753        were also very few tests of studied patterns with pcre_dfa_exec().
754    
755    27. If (?| is used to create subpatterns with duplicate numbers, they are now
756        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
757        on the other side of the coin, they are no longer allowed to have different
758        names, because these cannot be distinguished in PCRE, and this has caused
759        confusion. (This is a difference from Perl.)
760    
761    28. When duplicate subpattern names are present (necessarily with different
762        numbers, as required by 27 above), and a test is made by name in a
763        conditional pattern, either for a subpattern having been matched, or for
764        recursion in such a pattern, all the associated numbered subpatterns are
765        tested, and the overall condition is true if the condition is true for any
766        one of them. This is the way Perl works, and is also more like the way
767        testing by number works.
768    
769    
770    Version 7.9 11-Apr-09
771    ---------------------
772    
773    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
774        (pcretest), all targets were linked against these libraries. This included
775        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
776        libraries. This caused unwanted dependencies to be created. This problem
777        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
778        pcretest is linked with readline.
779    
780    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
781        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
782        moved outside it again, because FALSE and TRUE are already defined in AIX,
783        but BOOL is not.
784    
785    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
786        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
787    
788    4.  The pcregrep documentation said spaces were inserted as well as colons (or
789        hyphens) following file names and line numbers when outputting matching
790        lines. This is not true; no spaces are inserted. I have also clarified the
791        wording for the --colour (or --color) option.
792    
793    5.  In pcregrep, when --colour was used with -o, the list of matching strings
794        was not coloured; this is different to GNU grep, so I have changed it to be
795        the same.
796    
797    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
798        each matching line was coloured. Now it goes on to look for further matches
799        of any of the test patterns, which is the same behaviour as GNU grep.
800    
801    7.  A pattern that could match an empty string could cause pcregrep to loop; it
802        doesn't make sense to accept an empty string match in pcregrep, so I have
803        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
804        seems to be how GNU grep behaves.
805    
806    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
807        start or after a newline", because the conditional assertion was not being
808        correctly handled. The rule now is that both the assertion and what follows
809        in the first alternative must satisfy the test.
810    
811    9.  If auto-callout was enabled in a pattern with a conditional group whose
812        condition was an assertion, PCRE could crash during matching, both with
813        pcre_exec() and pcre_dfa_exec().
814    
815    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
816        used for matching.
817    
818    11. Unicode property support in character classes was not working for
819        characters (bytes) greater than 127 when not in UTF-8 mode.
820    
821    12. Added the -M command line option to pcretest.
822    
823    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
824    
825    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
826    
827    16. Added comments and documentation about mis-use of no_arg in the C++
828        wrapper.
829    
830    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
831        from Martin Jerabek that uses macro names for all relevant character and
832        string constants.
833    
834    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
835        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
836        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
837        these, but not everybody uses configure.
838    
839    19. A conditional group that had only one branch was not being correctly
840        recognized as an item that could match an empty string. This meant that an
841        enclosing group might also not be so recognized, causing infinite looping
842        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
843        with the subject "ab", where knowledge that the repeated group can match
844        nothing is needed in order to break the loop.
845    
846    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
847        exec(), but without supplying a callout function, matching went wrong.
848    
849    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
850        leak if the size of the offset vector was greater than 30. When the vector
851        is smaller, the saved offsets during recursion go onto a local stack
852        vector, but for larger vectors malloc() is used. It was failing to free
853        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
854        error, in fact).
855    
856    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
857        heapframe that is used only when UTF-8 support is enabled. This caused no
858        problem, but was untidy.
859    
860    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
861        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
862        included within another project.
863    
864    24. Steven Van Ingelgem's patches to add more options to the CMake support,
865        slightly modified by me:
866    
867          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
868              not building pcregrep.
869    
870          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
871              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
872    
873    25. Forward references, both numeric and by name, in patterns that made use of
874        duplicate group numbers, could behave incorrectly or give incorrect errors,
875        because when scanning forward to find the reference group, PCRE was not
876        taking into account the duplicate group numbers. A pattern such as
877        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
878    
879    26. Changed a few more instances of "const unsigned char *" to USPTR, making
880        the feature of a custom pointer more persuasive (as requested by a user).
881    
882    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
883        pcretest.c, inside #ifndefs, because it seems they are sometimes already
884        pre-defined.
885    
886    28. Added support for (*UTF8) at the start of a pattern.
887    
888    29. Arrange for flags added by the "release type" setting in CMake to be shown
889        in the configuration summary.
890    
891    
892    Version 7.8 05-Sep-08
893  ---------------------  ---------------------
894    
895   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one  1.  Replaced UCP searching code with optimized version as implemented for Ad
896      that is more "standard", making use of automake and other autotools. There      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
897        stage table and inline lookup instead of a function, giving speed ups of 2
898        to 5 times on some simple patterns that I tested. Permission was given to
899        distribute the MultiStage2.py script that generates the tables (it's not in
900        the tarball, but is in the Subversion repository).
901    
902    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
903        scripts.
904    
905    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
906        a group with a zero qualifier. The result of the study could be incorrect,
907        or the function might crash, depending on the pattern.
908    
909    4.  Caseless matching was not working for non-ASCII characters in back
910        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
911        It now works when Unicode Property Support is available.
912    
913    5.  In pcretest, an escape such as \x{de} in the data was always generating
914        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
915        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
916        truncation.
917    
918    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
919    
920    7.  Added two (int) casts to pcregrep when printing the difference of two
921        pointers, in case they are 64-bit values.
922    
923    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
924        test 2 if it fails.
925    
926    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
927        and a #define of that name to empty if it is not externally set. This is to
928        allow users of MSVC to set it if necessary.
929    
930    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
931        the convenience functions in the pcre_get.c source file.
932    
933    11. An option change at the start of a pattern that had top-level alternatives
934        could cause overwriting and/or a crash. This command provoked a crash in
935        some environments:
936    
937          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
938    
939        This potential security problem was recorded as CVE-2008-2371.
940    
941    12. For a pattern where the match had to start at the beginning or immediately
942        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
943        pcre_dfa_exec() could read past the end of the passed subject if there was
944        no match. To help with detecting such bugs (e.g. with valgrind), I modified
945        pcretest so that it places the subject at the end of its malloc-ed buffer.
946    
947    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
948        exec() might read past the end of the data buffer in UTF-8 mode.
949    
950    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
951        the data contained the byte 0x85 as part of a UTF-8 character within its
952        first line. This applied both to normal and DFA matching.
953    
954    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
955        /^[^d]*?$/8 failed to match "abc".
956    
957    16. Added a missing copyright notice to pcrecpp_internal.h.
958    
959    17. Make it more clear in the documentation that values returned from
960        pcre_exec() in ovector are byte offsets, not character counts.
961    
962    18. Tidied a few places to stop certain compilers from issuing warnings.
963    
964    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
965        supplied by Stefan Weber. I made a further small update for 7.8 because
966        there is a change of source arrangements: the pcre_searchfuncs.c module is
967        replaced by pcre_ucd.c.
968    
969    
970    Version 7.7 07-May-08
971    ---------------------
972    
973    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
974        a string to a long long, pretend we don't even have a long long." This is
975        done by checking for the strtoq, strtoll, and _strtoi64 functions.
976    
977    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
978        pre-7.6 versions, which defined a global no_arg variable instead of putting
979        it in the RE class. (See also #8 below.)
980    
981    3.  Remove a line of dead code, identified by coverity and reported by Nuno
982        Lopes.
983    
984    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
985    
986        (1) The include/exclude patterns were being applied to the whole pathnames
987            of files, instead of just to the final components.
988    
989        (2) If there was more than one level of directory, the subdirectories were
990            skipped unless they satisfied the include/exclude conditions. This is
991            inconsistent with GNU grep (and could even be seen as contrary to the
992            pcregrep specification - which I improved to make it absolutely clear).
993            The action now is always to scan all levels of directory, and just
994            apply the include/exclude patterns to regular files.
995    
996    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
997        --exclude_dir in the tests to avoid scanning .svn directories.
998    
999    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1000        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1001        doesn't support NULs in patterns.
1002    
1003    7.  Added some missing "const"s to declarations of static tables in
1004        pcre_compile.c and pcre_dfa_exec.c.
1005    
1006    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1007        caused by fix #2  above. (Subsequently also a second patch to fix the
1008        first patch. And a third patch - this was a messy problem.)
1009    
1010    9.  Applied Craig's patch to remove the use of push_back().
1011    
1012    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1013        matching function regexec().
1014    
1015    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1016        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1017        references. PCRE supports relative numbers with this syntax (I don't think
1018        Oniguruma does).
1019    
1020    12. Previously, a group with a zero repeat such as (...){0} was completely
1021        omitted from the compiled regex. However, this means that if the group
1022        was called as a subroutine from elsewhere in the pattern, things went wrong
1023        (an internal error was given). Such groups are now left in the compiled
1024        pattern, with a new opcode that causes them to be skipped at execution
1025        time.
1026    
1027    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1028        to the way PCRE behaves:
1029    
1030        (a) A lone ] character is dis-allowed (Perl treats it as data).
1031    
1032        (b) A back reference to an unmatched subpattern matches an empty string
1033            (Perl fails the current match path).
1034    
1035        (c) A data ] in a character class must be notated as \] because if the
1036            first data character in a class is ], it defines an empty class. (In
1037            Perl it is not possible to have an empty class.) The empty class []
1038            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1039            The negative empty class [^] matches any one character, independently
1040            of the DOTALL setting.
1041    
1042    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1043        non-existent subpattern following a character class starting with ']' and
1044        containing () gave an internal compiling error instead of "reference to
1045        non-existent subpattern". Fortunately, when the pattern did exist, the
1046        compiled code was correct. (When scanning forwards to check for the
1047        existencd of the subpattern, it was treating the data ']' as terminating
1048        the class, so got the count wrong. When actually compiling, the reference
1049        was subsequently set up correctly.)
1050    
1051    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1052        it was being rejected as not supported by pcre_dfa_exec(), even though
1053        other assertions are supported. I have made pcre_dfa_exec() support
1054        (*FAIL).
1055    
1056    16. The implementation of 13c above involved the invention of a new opcode,
1057        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1058        cannot be changed at match time, I realized I could make a small
1059        improvement to matching performance by compiling OP_ALLANY instead of
1060        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1061        on the OP_ANY path.
1062    
1063    17. Compiling pcretest on Windows with readline support failed without the
1064        following two fixes: (1) Make the unistd.h include conditional on
1065        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1066    
1067    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1068        ncurses library to be included for pcretest when ReadLine support is
1069        requested, but also to allow for it to be overridden. This patch came from
1070        Daniel Bergström.
1071    
1072    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1073        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1074        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1075        spotting this.
1076    
1077    
1078    Version 7.6 28-Jan-08
1079    ---------------------
1080    
1081    1.  A character class containing a very large number of characters with
1082        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1083        overflow.
1084    
1085    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1086        HAVE_LONG_LONG is not defined.
1087    
1088    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1089        bring them up to date and include new features. This patch includes:
1090    
1091        - Fixed PH's badly added libz and libbz2 support.
1092        - Fixed a problem with static linking.
1093        - Added pcredemo. [But later removed - see 7 below.]
1094        - Fixed dftables problem and added an option.
1095        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1096            HAVE_LONG_LONG.
1097        - Added readline support for pcretest.
1098        - Added an listing of the option settings after cmake has run.
1099    
1100    4.  A user submitted a patch to Makefile that makes it easy to create
1101        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1102        Makefile.am that cause it to include this special target, without
1103        affecting anything else. Note that the same mingw target plus all
1104        the other distribution libraries and programs are now supported
1105        when configuring with CMake (see 6 below) instead of with
1106        Configure/Make.
1107    
1108    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1109        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1110        exported in the Windows port". It has not yet been confirmed that the patch
1111        solves the problem, but it does no harm.
1112    
1113    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1114        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1115        with CMake, and also correct the comment about stack recursion.
1116    
1117    7.  Remove the automatic building of pcredemo from the ./configure system and
1118        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1119        of a program that users should build themselves after PCRE is installed, so
1120        building it automatically is not really right. What is more, it gave
1121        trouble in some build environments.
1122    
1123    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1124    
1125    
1126    Version 7.5 10-Jan-08
1127    ---------------------
1128    
1129    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1130        values in parens when parsing an RE using the C++ wrapper."
1131    
1132    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1133        Characters greater than 255 were excluded from the class instead of being
1134        included.
1135    
1136    3.  The same bug as (2) above applied to negated POSIX classes such as
1137        [:^space:].
1138    
1139    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1140        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1141        I have changed it.
1142    
1143    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1144        first named subpattern) and a construct such as (?&a) would reference the
1145        first named subpattern whose name started with "a" (in other words, the
1146        length check was missing). Both these problems are fixed. "Subpattern name
1147        expected" is now given for (?&) (a zero-length name), and this patch also
1148        makes it give the same error for \k'' (previously it complained that that
1149        was a reference to a non-existent subpattern).
1150    
1151    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1152        this is right because (?- can be followed by option settings as well as by
1153        digits. I have, however, made the messages clearer.
1154    
1155    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1156        than the number used in the conditional) now cause a compile-time error.
1157        This is actually not compatible with Perl, which accepts such patterns, but
1158        treats the conditional as always being FALSE (as PCRE used to), but it
1159        seems to me that giving a diagnostic is better.
1160    
1161    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1162        and messages.
1163    
1164    9.  Fix two occurrences of "backslash" in comments that should have been
1165        "backspace".
1166    
1167    10. Remove two redundant lines of code that can never be obeyed (their function
1168        was moved elsewhere).
1169    
1170    11. The program that makes PCRE's Unicode character property table had a bug
1171        which caused it to generate incorrect table entries for sequences of
1172        characters that have the same character type, but are in different scripts.
1173        It amalgamated them into a single range, with the script of the first of
1174        them. In other words, some characters were in the wrong script. There were
1175        thirteen such cases, affecting characters in the following ranges:
1176    
1177          U+002b0 - U+002c1
1178          U+0060c - U+0060d
1179          U+0061e - U+00612
1180          U+0064b - U+0065e
1181          U+0074d - U+0076d
1182          U+01800 - U+01805
1183          U+01d00 - U+01d77
1184          U+01d9b - U+01dbf
1185          U+0200b - U+0200f
1186          U+030fc - U+030fe
1187          U+03260 - U+0327f
1188          U+0fb46 - U+0fbb1
1189          U+10450 - U+1049d
1190    
1191    12. The -o option (show only the matching part of a line) for pcregrep was not
1192        compatible with GNU grep in that, if there was more than one match in a
1193        line, it showed only the first of them. It now behaves in the same way as
1194        GNU grep.
1195    
1196    13. If the -o and -v options were combined for pcregrep, it printed a blank
1197        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1198        does the same. The return code can be used to tell if there were any
1199        non-matching lines.
1200    
1201    14. Added --file-offsets and --line-offsets to pcregrep.
1202    
1203    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1204        infinitely looping recursion. The bug was that positive lookaheads were not
1205        being skipped when checking for a possible empty match (negative lookaheads
1206        and both kinds of lookbehind were skipped).
1207    
1208    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1209        inclusion of <windows.h> to before rather than after the definition of
1210        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1211    
1212    17. Specifying a possessive quantifier with a specific limit for a Unicode
1213        character property caused pcre_compile() to compile bad code, which led at
1214        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1215        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1216        caused the error; without that there was no problem.
1217    
1218    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1219    
1220    19. Added --enable-pcretest-libreadline.
1221    
1222    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1223        RE::GlobalReplace(). As a result, the number of replacements returned was
1224        double what it should be. I removed one of the increments, but Craig sent a
1225        later patch that removed the other one (the right fix) and added unit tests
1226        that check the return values (which was not done before).
1227    
1228    21. Several CMake things:
1229    
1230        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1231            the names libpcre and libpcreposix, not just pcre and pcreposix.
1232    
1233        (2) The above change means that pcretest and pcregrep are now correctly
1234            linked with the newly-built libraries, not previously installed ones.
1235    
1236        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1237    
1238    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1239        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1240        UTF-8 newline character). The key issue is that the pattern starts .*;
1241        this means that the match must be either at the beginning, or after a
1242        newline. The bug was in the code for advancing after a failed match and
1243        checking that the new position followed a newline. It was not taking
1244        account of UTF-8 characters correctly.
1245    
1246    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1247        character classes. PCRE was not treating the sequence [:...:] as a
1248        character class unless the ... were all letters. Perl, however, seems to
1249        allow any characters between [: and :], though of course it rejects as
1250        unknown any "names" that contain non-letters, because all the known class
1251        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1252        for example, whereas PCRE did not - it did not recognize a POSIX character
1253        class. This seemed a bit dangerous, so the code has been changed to be
1254        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1255        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1256        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1257        Perl does, and where it didn't before.
1258    
1259    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1260        Windows environments %n is disabled by default.
1261    
1262    
1263    Version 7.4 21-Sep-07
1264    ---------------------
1265    
1266    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1267        means that a class such as [\s] counted as "explicit reference to CR or
1268        LF". That isn't really right - the whole point of the change was to try to
1269        help when there was an actual mention of one of the two characters. So now
1270        the change happens only if \r or \n (or a literal CR or LF) character is
1271        encountered.
1272    
1273    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1274        of both had grown to the point where there were only 3 bits left.
1275        Fortunately, there was spare space in the data structure, and so I have
1276        moved the internal flags into a new 16-bit field to free up more option
1277        bits.
1278    
1279    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1280        but did not set the internal JCHANGED flag - either of these is enough to
1281        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1282        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1283        start sets both bits.
1284    
1285    4.  Added options (at build time, compile time, exec time) to change \R from
1286        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1287    
1288    5.  doc/pcresyntax.html was missing from the distribution.
1289    
1290    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1291        compatibility, even though it is no longer used.
1292    
1293    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1294        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1295        windows.h file is present (where different names are used). [This was
1296        reversed later after testing - see 16 below.]
1297    
1298    8.  Changed all #include <config.h> to #include "config.h". There were also
1299        some further <pcre.h> cases that I changed to "pcre.h".
1300    
1301    9.  When pcregrep was used with the --colour option, it missed the line ending
1302        sequence off the lines that it output.
1303    
1304    10. It was pointed out to me that arrays of string pointers cause lots of
1305        relocations when a shared library is dynamically loaded. A technique of
1306        using a single long string with a table of offsets can drastically reduce
1307        these. I have refactored PCRE in four places to do this. The result is
1308        dramatic:
1309    
1310          Originally:                          290
1311          After changing UCP table:            187
1312          After changing error message table:   43
1313          After changing table of "verbs"       36
1314          After changing table of Posix names   22
1315    
1316        Thanks to the folks working on Gregex for glib for this insight.
1317    
1318    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1319        unicode-properties was also set.
1320    
1321    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1322    
1323    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1324        checked only for CRLF.
1325    
1326    14. Added casts to pcretest.c to avoid compiler warnings.
1327    
1328    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1329    
1330    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1331        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1332        entirely. This removes changes made in 7 above.
1333    
1334    17. The CMake files have been updated, and there is now more information about
1335        building with CMake in the NON-UNIX-USE document.
1336    
1337    
1338    Version 7.3 28-Aug-07
1339    ---------------------
1340    
1341     1. In the rejigging of the build system that eventually resulted in 7.1, the
1342        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1343        brackets there is not right, since it causes compilers to look for an
1344        installed pcre.h, not the version that is in the source that is being
1345        compiled (which of course may be different). I have changed it back to:
1346    
1347          #include "pcre.h"
1348    
1349        I have a vague recollection that the change was concerned with compiling in
1350        different directories, but in the new build system, that is taken care of
1351        by the VPATH setting the Makefile.
1352    
1353     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1354        when the subject happened to end in the byte 0x85 (e.g. if the last
1355        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1356        characters but of course it shouldn't be taken as a newline when it is part
1357        of another character. The bug was that, for an unlimited repeat of . in
1358        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1359        characters when looking for a newline.
1360    
1361     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1362    
1363     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1364        in debug output.
1365    
1366     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1367        long printing in the pcrecpp unittest when running under MinGW.
1368    
1369     6. ESC_K was left out of the EBCDIC table.
1370    
1371     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1372        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1373        limit also applies to "virtual nesting" when a pattern is recursive, and in
1374        this case 1000 isn't so big. I have been able to remove this limit at the
1375        expense of backing off one optimization in certain circumstances. Normally,
1376        when pcre_exec() would call its internal match() function recursively and
1377        immediately return the result unconditionally, it uses a "tail recursion"
1378        feature to save stack. However, when a subpattern that can match an empty
1379        string has an unlimited repetition quantifier, it no longer makes this
1380        optimization. That gives it a stack frame in which to save the data for
1381        checking that an empty string has been matched. Previously this was taken
1382        from the 1000-entry workspace that had been reserved. So now there is no
1383        explicit limit, but more stack is used.
1384    
1385     8. Applied Daniel's patches to solve problems with the import/export magic
1386        syntax that is required for Windows, and which was going wrong for the
1387        pcreposix and pcrecpp parts of the library. These were overlooked when this
1388        problem was solved for the main library.
1389    
1390     9. There were some crude static tests to avoid integer overflow when computing
1391        the size of patterns that contain repeated groups with explicit upper
1392        limits. As the maximum quantifier is 65535, the maximum group length was
1393        set at 30,000 so that the product of these two numbers did not overflow a
1394        32-bit integer. However, it turns out that people want to use groups that
1395        are longer than 30,000 bytes (though not repeat them that many times).
1396        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1397        made it possible to implement the integer overflow checks in a much more
1398        dynamic way, which I have now done. The artificial limitation on group
1399        length has been removed - we now have only the limit on the total length of
1400        the compiled pattern, which depends on the LINK_SIZE setting.
1401    
1402    10. Fixed a bug in the documentation for get/copy named substring when
1403        duplicate names are permitted. If none of the named substrings are set, the
1404        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1405        empty string.
1406    
1407    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1408        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1409        because the ] is interpreted as the first data character and the
1410        terminating ] is not found. PCRE has been made compatible with Perl in this
1411        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1412        cause memory overwriting.
1413    
1414    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1415        string has been matched (to stop an infinite loop). It was not recognizing
1416        a conditional subpattern that could match an empty string if that
1417        subpattern was within another subpattern. For example, it looped when
1418        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1419        condition was not nested. This bug has been fixed.
1420    
1421    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1422        past the start of the subject in the presence of bytes with the top bit
1423        set, for example "\x8aBCD".
1424    
1425    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1426        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1427    
1428    14. Optimized (?!) to (*FAIL).
1429    
1430    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1431        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1432        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1433        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1434        does: it's just the validity check that is more restrictive.
1435    
1436    16. Inserted checks for integer overflows during escape sequence (backslash)
1437        processing, and also fixed erroneous offset values for syntax errors during
1438        backslash processing.
1439    
1440    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1441        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1442    
1443    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1444        caused an overrun.
1445    
1446    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1447        something other than just ASCII characters) inside a group that had an
1448        unlimited repeat caused a loop at compile time (while checking to see
1449        whether the group could match an empty string).
1450    
1451    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1452        [\P{Any}] did so. (Error in the code for printing property names.)
1453    
1454    21. An orphan \E inside a character class could cause a crash.
1455    
1456    22. A repeated capturing bracket such as (A)? could cause a wild memory
1457        reference during compilation.
1458    
1459    23. There are several functions in pcre_compile() that scan along a compiled
1460        expression for various reasons (e.g. to see if it's fixed length for look
1461        behind). There were bugs in these functions when a repeated \p or \P was
1462        present in the pattern. These operators have additional parameters compared
1463        with \d, etc, and these were not being taken into account when moving along
1464        the compiled data. Specifically:
1465    
1466        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1467            length.
1468    
1469        (b) An item such as \pL+ within a repeated group could cause crashes or
1470            loops.
1471    
1472        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1473            "reference to non-existent subpattern" error.
1474    
1475        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1476    
1477    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1478        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1479    
1480    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1481    
1482    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1483        character were causing crashes (broken optimization).
1484    
1485    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1486        \p or \P) caused a compile-time loop.
1487    
1488    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1489        break. For example, the unstudied pattern [\r\n]A does not match the string
1490        "\r\nA" because change 7.0/46 below moves the current point on by two
1491        characters after failing to match at the start. However, the pattern \nA
1492        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1493        the same is true. There doesn't seem any very clean way out of this, but
1494        what I have chosen to do makes the common cases work: PCRE now takes note
1495        of whether there can be an explicit match for \r or \n anywhere in the
1496        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1497        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1498        pattern has explicit CR or LF references.
1499    
1500    29. Added (*CR) etc for changing newline setting at start of pattern.
1501    
1502    
1503    Version 7.2 19-Jun-07
1504    ---------------------
1505    
1506     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1507        which is apparently normally available under Windows.
1508    
1509     2. Re-jig the pcregrep tests with different newline settings in an attempt
1510        to make them independent of the local environment's newline setting.
1511    
1512     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1513    
1514     4. Some of the "internals" tests were previously cut out when the link size
1515        was not 2, because the output contained actual offsets. The recent new
1516        "Z" feature of pcretest means that these can be cut out, making the tests
1517        usable with all link sizes.
1518    
1519     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1520        stack recursion. This gives a massive performance boost under BSD, but just
1521        a small improvement under Linux. However, it saves one field in the frame
1522        in all cases.
1523    
1524     6. Added more features from the forthcoming Perl 5.10:
1525    
1526        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1527            recursion call. It refers to the nth most recently opened parentheses.
1528    
1529        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1530            to be opened parentheses.
1531    
1532        (c) Conditions that refer to capturing parentheses can be specified
1533            relatively, for example, (?(-2)... or (?(+3)...
1534    
1535        (d) \K resets the start of the current match so that everything before
1536            is not part of it.
1537    
1538        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1539    
1540        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1541            reference syntax.
1542    
1543        (g) (?| introduces a group in which the numbering of parentheses in each
1544            alternative starts with the same number.
1545    
1546        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1547    
1548     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1549        PCRE_INFO_JCHANGED.
1550    
1551     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1552        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1553        for detecting groups that can match an empty string.
1554    
1555     9. A pattern with a very large number of alternatives (more than several
1556        hundred) was running out of internal workspace during the pre-compile
1557        phase, where pcre_compile() figures out how much memory will be needed. A
1558        bit of new cunning has reduced the workspace needed for groups with
1559        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1560        workspace instead of running out of the 4096 that are available.
1561    
1562    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1563    
1564    11. Applied patch from Google to remove an optimization that didn't quite work.
1565        The report of the bug said:
1566    
1567          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1568          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1569          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1570    
1571    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1572        it matched the wrong number of bytes.
1573    
1574    
1575    Version 7.1 24-Apr-07
1576    ---------------------
1577    
1578     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1579        that is more "standard", making use of automake and other Autotools. There
1580      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
1581      on this.      on this.
1582    
1583   2. I had an email from Eric Raymond about problems translating some of PCRE's   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1584      man pages to HTML (despite the fact that I distribute HTML pages, some      for recursive directory scanning broke on some systems because the files
1585      people do their own conversions for various reasons). The problems      are not scanned in any specific order and on different systems the order
1586      concerned the use of low-level troff macros .br and .in. I have therefore      was different. A call to "sort" has been inserted into RunGrepTest for the
1587      removed all such uses from the man pages (some were redundant, some could      approprate test as a short-term fix. In the longer term there may be an
1588      be replaced by .nf/.fi pairs). The maintain/132html script that I use to      alternative.
1589      generate HTML has been updated to handle .nf/.fi and to complain if it  
1590      encounters .br or .in.   3. I had an email from Eric Raymond about problems translating some of PCRE's
1591        man pages to HTML (despite the fact that I distribute HTML pages, some
1592        people do their own conversions for various reasons). The problems
1593        concerned the use of low-level troff macros .br and .in. I have therefore
1594        removed all such uses from the man pages (some were redundant, some could
1595        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1596        HTML has been updated to handle .nf/.fi and to complain if it encounters
1597        .br or .in.
1598    
1599     4. Updated comments in configure.ac that get placed in config.h.in and also
1600        arranged for config.h to be included in the distribution, with the name
1601        config.h.generic, for the benefit of those who have to compile without
1602        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1603    
1604     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1605        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1606        makevp.bat for the current PCRE, using the additional files
1607        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1608    
1609     6. A Windows user reported a minor discrepancy with test 2, which turned out
1610        to be caused by a trailing space on an input line that had got lost in his
1611        copy. The trailing space was an accident, so I've just removed it.
1612    
1613     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1614        that is needed.
1615    
1616     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1617        as "const" (a) because they are and (b) because it helps the PHP
1618        maintainers who have recently made a script to detect big data structures
1619        in the php code that should be moved to the .rodata section. I remembered
1620        to update Builducptable as well, so it won't revert if ucptable.h is ever
1621        re-created.
1622    
1623     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1624        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1625        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1626        support is not required. This saves 1.5-2K of code, which is important in
1627        some applications.
1628    
1629        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1630        so as not to refer to the tables, even though these functions will never be
1631        called when UTF-8 support is disabled. Otherwise there are problems with a
1632        shared library.
1633    
1634    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1635    
1636        (a) It was defining its arguments as char * instead of void *.
1637    
1638        (b) It was assuming that all moves were upwards in memory; this was true
1639            a long time ago when I wrote it, but is no longer the case.
1640    
1641        The emulated memove() is provided for those environments that have neither
1642        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1643        is clearly not the case, as these two bugs were recently reported.
1644    
1645    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1646        and Detrail to create the HTML documentation, the .txt form of the man
1647        pages, and it removes trailing spaces from listed files. It also creates
1648        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1649        case, it wraps all the #defines with #ifndefs. This script should be run
1650        before "make dist".
1651    
1652    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1653        with Unicode property support.
1654    
1655        (a) For a maximizing quantifier, if the two different cases of the
1656            character were of different lengths in their UTF-8 codings (there are
1657            some cases like this - I found 11), and the matching function had to
1658            back up over a mixture of the two cases, it incorrectly assumed they
1659            were both the same length.
1660    
1661        (b) When PCRE was configured to use the heap rather than the stack for
1662            recursion during matching, it was not correctly preserving the data for
1663            the other case of a UTF-8 character when checking ahead for a match
1664            while processing a minimizing repeat. If the check also involved
1665            matching a wide character, but failed, corruption could cause an
1666            erroneous result when trying to check for a repeat of the original
1667            character.
1668    
1669    13. Some tidying changes to the testing mechanism:
1670    
1671        (a) The RunTest script now detects the internal link size and whether there
1672            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1673            values substituted by "configure". (The RunGrepTest script already did
1674            this for UTF-8.) The configure.ac script no longer substitutes the
1675            relevant variables.
1676    
1677        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1678            with length and offset values. This means that the output is different
1679            for different internal link sizes. Test 2 is skipped for link sizes
1680            other than 2 because of this, bypassing the problem. Unfortunately,
1681            there was also a test in test 3 (the locale tests) that used /B and
1682            failed for link sizes other than 2. Rather than cut the whole test out,
1683            I have added a new /Z option to pcretest that replaces the length and
1684            offset values with spaces. This is now used to make test 3 independent
1685            of link size. (Test 2 will be tidied up later.)
1686    
1687    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1688        segmentation fault instead of returning the appropriate error message.
1689    
1690    15. In multiline mode when the newline sequence was set to "any", the pattern
1691        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1692        This doesn't seem right; it now treats the CRLF combination as the line
1693        ending, and so does not match in that case. It's only a pattern such as ^$
1694        that would hit this one: something like ^ABC$ would have failed after \r
1695        and then tried again after \r\n.
1696    
1697    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1698        in an attempt to make files that differ only in their line terminators
1699        compare equal. This works on Linux.
1700    
1701    17. Under certain error circumstances pcregrep might try to free random memory
1702        as it exited. This is now fixed, thanks to valgrind.
1703    
1704    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1705        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1706        was because its rules for how to advance for /g after matching an empty
1707        string at the end of a line did not allow for this case. They now check for
1708        it specially.
1709    
1710    20. pcretest is supposed to handle patterns and data of any length, by
1711        extending its buffers when necessary. It was getting this wrong when the
1712        buffer for a data line had to be extended.
1713    
1714    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1715        CRLF as a newline sequence.
1716    
1717    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1718        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1719        I have nevertheless tidied it up.
1720    
1721    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1722    
1723    24. Added a man page for pcre-config.
1724    
1725    
1726  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1727  ---------------------  ---------------------

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