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revision 165 by ph10, Wed May 9 10:50:57 2007 UTC revision 653 by ph10, Tue Aug 2 09:15:13 2011 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 01-May-07  Version 8.13 02-Aug-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, now 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 now
111        *disables* studying, thereby overriding the use of -s on the command line
112        (see 14 above). This is necessary for one or two tests to keep the output
113        identical in both cases.
114    
115    21. When (*ACCEPT) was used in an assertion that matched an empty string and
116        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
117    
118    22. When an atomic group that contained a capturing parenthesis was
119        successfully matched, but the branch in which it appeared failed, the
120        capturing was not being forgotten if a higher numbered group was later
121        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
122        group 1 to "a", when in fact it should be unset. This applied to multi-
123        branched capturing and non-capturing groups, repeated or not, and also to
124        positive assertions (capturing in negative assertions does not happen
125        in PCRE) and also to nested atomic groups.
126    
127    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
128        subject after a captured substring, to make it easier to tell which of a
129        number of identical substrings has been captured.
130    
131    24. The way atomic groups are processed by pcre_exec() has been changed so that
132        if they are repeated, backtracking one repetition now resets captured
133        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
134        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
135        "aaa". Previously, it would have been "a". As part of this code
136        refactoring, the way recursive calls are handled has also been changed.
137    
138    25. If an assertion condition captured any substrings, they were not passed
139        back unless some other capturing happened later. For example, if
140        (?(?=(a))a) was matched against "a", no capturing was returned.
141    
142    26. When studying a pattern that contained subroutine calls or assertions,
143        the code for finding the minimum length of a possible match was handling
144        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
145        group 1 called group 2 while simultaneously a separate group 2 called group
146        1). A stack overflow occurred in this case. I have fixed this by limiting
147        the recursion depth to 10.
148    
149    27. Updated RunTest.bat in the distribution to the version supplied by Tom
150        Fortmann. This supports explicit test numbers on the command line, and has
151        argument validation and error reporting.
152    
153    28. An instance of \X with an unlimited repeat could fail if at any point the
154        first character it looked at was a mark character.
155    
156    29. Some minor code refactoring concerning Unicode properties and scripts
157        should reduce the stack requirement of match() slightly.
158    
159    30. Added the '=' option to pcretest to check the setting of unused capturing
160        slots at the end of the pattern, which are documented as being -1, but are
161        not included in the return count.
162    
163    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
164        compiled something random. Now it gives a compile-time error (as does
165        Perl).
166    
167    32. A *MARK encountered during the processing of a positive assertion is now
168        recorded and passed back (compatible with Perl).
169    
170    33. If --only-matching or --colour was set on a pcregrep call whose pattern
171        had alternative anchored branches, the search for a second match in a line
172        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
173        matched the line "0102" twice. The same bug affected patterns that started
174        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
175        twice.
176    
177    34. Previously, PCRE did not allow quantification of assertions. However, Perl
178        does, and because of capturing effects, quantifying parenthesized
179        assertions may at times be useful. Quantifiers are now allowed for
180        parenthesized assertions.
181    
182    35. A minor code tidy in pcre_compile() when checking options for \R usage.
183    
184    36. \g was being checked for fancy things in a character class, when it should
185        just be a literal "g".
186    
187    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
188        appearance of a nested POSIX class supersedes an apparent external class.
189        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
190        unescaped square brackets may also appear as part of class names. For
191        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
192        more like Perl.
193    
194    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
195        was because it thought it was \N{name}, which is not supported).
196    
197    39. Add minix to OS list not supporting the -S option in pcretest.
198    
199    40. PCRE tries to detect cases of infinite recursion at compile time, but it
200        cannot analyze patterns in sufficient detail to catch mutual recursions
201        such as ((?1))((?2)). There is now a runtime test that gives an error if a
202        subgroup is called recursively as a subpattern for a second time at the
203        same position in the subject string. In previous releases this might have
204        been caught by the recursion limit, or it might have run out of stack.
205    
206    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
207        happen only once. PCRE was, however incorrectly giving a compile time error
208        "recursive call could loop indefinitely" because it cannot analyze the
209        pattern in sufficient detail. The compile time test no longer happens when
210        PCRE is compiling a conditional subpattern, but actual runaway loops are
211        now caught at runtime (see 40 above).
212    
213    42. It seems that Perl allows any characters other than a closing parenthesis
214        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
215        has been changed to be the same.
216    
217    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
218        as not to get warnings when autogen.sh is called. Also changed
219        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
220    
221    44. To help people who use pcregrep to scan files containing exceedingly long
222        lines, the following changes have been made:
223    
224        (a) The default value of the buffer size parameter has been increased from
225            8K to 20K. (The actual buffer used is three times this size.)
226    
227        (b) The default can be changed by ./configure --with-pcregrep-bufsiz when
228            PCRE is built.
229    
230        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
231            to be set at run time.
232    
233        (d) Numerical values in pcregrep options can be followed by K or M, for
234            example --buffer-size=50K.
235    
236        (e) If a line being scanned overflows pcregrep's buffer, an error is now
237            given and the return code is set to 2.
238    
239    45. Add a pointer to the latest mark to the callout data block.
240    
241    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
242        partial match of an empty string instead of no match. This was specific to
243        the use of ".".
244    
245    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
246        complete match instead of a partial match. This bug was dependent on both
247        the PCRE_UTF8 and PCRE_DOTALL options being set.
248    
249    
250    Version 8.12 15-Jan-2011
251    ------------------------
252    
253    1.  Fixed some typos in the markup of the man pages, and wrote a script that
254        checks for such things as part of the documentation building process.
255    
256    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
257        --match-limit and --recursion-limit options (added for 8.11). In
258        particular, this made one of the standard tests fail. (The integer value
259        went into the wrong half of a long int.)
260    
261    3.  If the --colour option was given to pcregrep with -v (invert match), it
262        did strange things, either producing crazy output, or crashing. It should,
263        of course, ignore a request for colour when reporting lines that do not
264        match.
265    
266    4.  Another pcregrep bug caused similar problems if --colour was specified with
267        -M (multiline) and the pattern match finished with a line ending.
268    
269    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
270        matched in multiline mode, the following line was shown as part of the
271        match. This seems wrong, so I have changed it.
272    
273    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
274        the check for further matches in the same line (so they could be coloured)
275        to overrun the end of the current line. If another match was found, it was
276        incorrectly shown (and then shown again when found in the next line).
277    
278    7.  If pcregrep was compiled under Windows, there was a reference to the
279        function pcregrep_exit() before it was defined. I am assuming this was
280        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
281        reported by a user. I've moved the definition above the reference.
282    
283    
284    Version 8.11 10-Dec-2010
285    ------------------------
286    
287    1.  (*THEN) was not working properly if there were untried alternatives prior
288        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
289        backtracked to try for "b" instead of moving to the next alternative branch
290        at the same level (in this case, to look for "c"). The Perl documentation
291        is clear that when (*THEN) is backtracked onto, it goes to the "next
292        alternative in the innermost enclosing group".
293    
294    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
295        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
296        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
297        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
298        (*THEN).
299    
300    3.  If \s appeared in a character class, it removed the VT character from
301        the class, even if it had been included by some previous item, for example
302        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
303        of \s, but is part of the POSIX "space" class.)
304    
305    4.  A partial match never returns an empty string (because you can always
306        match an empty string at the end of the subject); however the checking for
307        an empty string was starting at the "start of match" point. This has been
308        changed to the "earliest inspected character" point, because the returned
309        data for a partial match starts at this character. This means that, for
310        example, /(?<=abc)def/ gives a partial match for the subject "abc"
311        (previously it gave "no match").
312    
313    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
314        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
315        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
316        has an implication that the given string is incomplete (because a partial
317        match is preferred over a full match). For this reason, these items now
318        give a partial match in this situation. [Aside: previously, the one case
319        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
320        match rather than a full match, which was wrong by the old rules, but is
321        now correct.]
322    
323    6.  There was a bug in the handling of #-introduced comments, recognized when
324        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
325        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
326        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
327        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
328        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
329        places in pcre_compile().
330    
331    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
332        comments when looking ahead for named forward references to subpatterns,
333        the only newline sequence it recognized was NL. It now handles newlines
334        according to the set newline convention.
335    
336    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
337        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
338        cater for a lack of strerror(). These oversights have been fixed.
339    
340    9.  Added --match-limit and --recursion-limit to pcregrep.
341    
342    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
343    
344    11. When the -o option was used, pcregrep was setting a return code of 1, even
345        when matches were found, and --line-buffered was not being honoured.
346    
347    12. Added an optional parentheses number to the -o and --only-matching options
348        of pcregrep.
349    
350    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
351        can match an empty string. The code to do it in pcretest and pcredemo
352        needed fixing:
353    
354        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
355            only one byte after an empty string match just before CRLF (this case
356            just got forgotten; "any" and "anycrlf" were OK).
357    
358        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
359            mode when an empty string match preceded an ASCII character followed by
360            a non-ASCII character. (The code for advancing by one character rather
361            than one byte was nonsense.)
362    
363        (c) The pcredemo.c sample program did not have any code at all to handle
364            the cases when CRLF is a valid newline sequence.
365    
366    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
367        as a starting offset was within the subject string. There is now a new
368        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
369        negative or greater than the length of the string. In order to test this,
370        pcretest is extended to allow the setting of negative starting offsets.
371    
372    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
373        starting offset points to the beginning of a UTF-8 character was
374        unnecessarily clumsy. I tidied it up.
375    
376    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
377        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
378    
379    17. Nobody had reported that the --include_dir option, which was added in
380        release 7.7 should have been called --include-dir (hyphen, not underscore)
381        for compatibility with GNU grep. I have changed it to --include-dir, but
382        left --include_dir as an undocumented synonym, and the same for
383        --exclude-dir, though that is not available in GNU grep, at least as of
384        release 2.5.4.
385    
386    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
387        characters from a string of bytes) have been redefined so as not to use
388        loops, in order to improve performance in some environments. At the same
389        time, I abstracted some of the common code into auxiliary macros to save
390        repetition (this should not affect the compiled code).
391    
392    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
393        compile-time error is now given if \c is not followed by an ASCII
394        character, that is, a byte less than 128. (In EBCDIC mode, the code is
395        different, and any byte value is allowed.)
396    
397    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
398        START_OPTIMIZE option, which is now allowed at compile time - but just
399        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
400        to pcregrep and other applications that have no direct access to PCRE
401        options. The new /Y option in pcretest sets this option when calling
402        pcre_compile().
403    
404    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
405        back references. Groups containing recursive back references were forced to
406        be atomic by that change, but in the case of named groups, the amount of
407        memory required was incorrectly computed, leading to "Failed: internal
408        error: code overflow". This has been fixed.
409    
410    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
411        pcretest.c, to avoid build problems in some Borland environments.
412    
413    
414    Version 8.10 25-Jun-2010
415    ------------------------
416    
417    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
418        THEN.
419    
420    2.  (*ACCEPT) was not working when inside an atomic group.
421    
422    3.  Inside a character class, \B is treated as a literal by default, but
423        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
424        causes the error). The code is unchanged, but I tidied the documentation.
425    
426    4.  Inside a character class, PCRE always treated \R and \X as literals,
427        whereas Perl faults them if its -w option is set. I have changed PCRE so
428        that it faults them when PCRE_EXTRA is set.
429    
430    5.  Added support for \N, which always matches any character other than
431        newline. (It is the same as "." when PCRE_DOTALL is not set.)
432    
433    6.  When compiling pcregrep with newer versions of gcc which may have
434        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
435        declared with attribute warn_unused_result" were given. Just casting the
436        result to (void) does not stop the warnings; a more elaborate fudge is
437        needed. I've used a macro to implement this.
438    
439    7.  Minor change to pcretest.c to avoid a compiler warning.
440    
441    8.  Added four artifical Unicode properties to help with an option to make
442        \s etc use properties (see next item). The new properties are: Xan
443        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
444    
445    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
446        use Unicode properties. (*UCP) at the start of a pattern can be used to set
447        this option. Modified pcretest to add /W to test this facility. Added
448        REG_UCP to make it available via the POSIX interface.
449    
450    10. Added --line-buffered to pcregrep.
451    
452    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
453        studied, and the match started with a letter with a code point greater than
454        127 whose first byte was different to the first byte of the other case of
455        the letter, the other case of this starting letter was not recognized
456        (#976).
457    
458    12. If a pattern that was studied started with a repeated Unicode property
459        test, for example, \p{Nd}+, there was the theoretical possibility of
460        setting up an incorrect bitmap of starting bytes, but fortunately it could
461        not have actually happened in practice until change 8 above was made (it
462        added property types that matched character-matching opcodes).
463    
464    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
465        possible starting bytes for non-anchored patterns.
466    
467    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
468        \R, and also a number of cases that involve Unicode properties, both
469        explicit and implicit when PCRE_UCP is set.
470    
471    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
472        input, it could crash or give wrong results if characters with values
473        greater than 0xc0 were present in the subject string. (Detail: it assumed
474        UTF-8 input when processing these items.)
475    
476    16. Added a lot of (int) casts to avoid compiler warnings in systems where
477        size_t is 64-bit (#991).
478    
479    17. Added a check for running out of memory when PCRE is compiled with
480        --disable-stack-for-recursion (#990).
481    
482    18. If the last data line in a file for pcretest does not have a newline on
483        the end, a newline was missing in the output.
484    
485    19. The default pcre_chartables.c file recognizes only ASCII characters (values
486        less than 128) in its various bitmaps. However, there is a facility for
487        generating tables according to the current locale when PCRE is compiled. It
488        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
489        characters, are recognized by isspace() and therefore were getting set in
490        these tables, and indeed these tables seem to approximate to ISO 8859. This
491        caused a problem in UTF-8 mode when pcre_study() was used to create a list
492        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
493        which of course cannot start UTF-8 characters. I have changed the code so
494        that only real ASCII characters (less than 128) and the correct starting
495        bytes for UTF-8 encodings are set for characters greater than 127 when in
496        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
497        altogether.)
498    
499    20. Added the /T option to pcretest so as to be able to run tests with non-
500        standard character tables, thus making it possible to include the tests
501        used for 19 above in the standard set of tests.
502    
503    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
504        reference to a subpattern the other side of a comment that contains an
505        opening parenthesis caused either an internal compiling error, or a
506        reference to the wrong subpattern.
507    
508    
509    Version 8.02 19-Mar-2010
510    ------------------------
511    
512    1.  The Unicode data tables have been updated to Unicode 5.2.0.
513    
514    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
515        configured.
516    
517    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
518        original author of that file, following a query about its status.
519    
520    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
521        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
522    
523    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
524        quantifier applied to a forward-referencing subroutine call, could compile
525        incorrect code or give the error "internal error: previously-checked
526        referenced subpattern not found".
527    
528    6.  Both MS Visual Studio and Symbian OS have problems with initializing
529        variables to point to external functions. For these systems, therefore,
530        pcre_malloc etc. are now initialized to local functions that call the
531        relevant global functions.
532    
533    7.  There were two entries missing in the vectors called coptable and poptable
534        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
535        I've fixed the data, and added a kludgy way of testing at compile time that
536        the lengths are correct (equal to the number of opcodes).
537    
538    8.  Following on from 7, I added a similar kludge to check the length of the
539        eint vector in pcreposix.c.
540    
541    9.  Error texts for pcre_compile() are held as one long string to avoid too
542        much relocation at load time. To find a text, the string is searched,
543        counting zeros. There was no check for running off the end of the string,
544        which could happen if a new error number was added without updating the
545        string.
546    
547    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
548    
549    11. \K was not working if it appeared in an atomic group or in a group that
550        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
551        \K is "not well defined" if used in an assertion. PCRE now accepts it if
552        the assertion is positive, but not if it is negative.
553    
554    12. Change 11 fortuitously reduced the size of the stack frame used in the
555        "match()" function of pcre_exec.c by one pointer. Forthcoming
556        implementation of support for (*MARK) will need an extra pointer on the
557        stack; I have reserved it now, so that the stack frame size does not
558        decrease.
559    
560    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
561        item in branch that calls a recursion is a subroutine call - as in the
562        second branch in the above example - was incorrectly given the compile-
563        time error "recursive call could loop indefinitely" because pcre_compile()
564        was not correctly checking the subroutine for matching a non-empty string.
565    
566    14. The checks for overrunning compiling workspace could trigger after an
567        overrun had occurred. This is a "should never occur" error, but it can be
568        triggered by pathological patterns such as hundreds of nested parentheses.
569        The checks now trigger 100 bytes before the end of the workspace.
570    
571    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
572    
573    
574    Version 8.01 19-Jan-2010
575    ------------------------
576    
577    1.  If a pattern contained a conditional subpattern with only one branch (in
578        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
579        computed the wrong minimum data length (which is of course zero for such
580        subpatterns). This could cause incorrect "no match" results.
581    
582    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
583        the pattern is reset in the first branch, pcre_compile() failed with
584        "internal error: code overflow at offset...". This happened only when
585        the reset was to the original external option setting. (An optimization
586        abstracts leading options settings into an external setting, which was the
587        cause of this.)
588    
589    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
590        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
591        assertion pattern did not match (meaning that the assertion was true), it
592        was incorrectly treated as false if the SKIP had been reached during the
593        matching. This also applied to assertions used as conditions.
594    
595    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
596        assertion subpattern, including such a pattern used as a condition,
597        unpredictable results occurred, instead of the error return
598        PCRE_ERROR_DFA_UITEM.
599    
600    5.  The C++ GlobalReplace function was not working like Perl for the special
601        situation when an empty string is matched. It now does the fancy magic
602        stuff that is necessary.
603    
604    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
605        removed. (These were left over from very, very early versions of PCRE.)
606    
607    7.  Some cosmetic changes to the code to make life easier when compiling it
608        as part of something else:
609    
610        (a) Change DEBUG to PCRE_DEBUG.
611    
612        (b) In pcre_compile(), rename the member of the "branch_chain" structure
613            called "current" as "current_branch", to prevent a collision with the
614            Linux macro when compiled as a kernel module.
615    
616        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
617            prevent a collision with the Linux macro when compiled as a kernel
618            module.
619    
620    8.  In pcre_compile() there are some checks for integer overflows that used to
621        cast potentially large values to (double). This has been changed to that
622        when building, a check for int64_t is made, and if it is found, it is used
623        instead, thus avoiding the use of floating point arithmetic. (There is no
624        other use of FP in PCRE.) If int64_t is not found, the fallback is to
625        double.
626    
627    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
628        2005 (difference between two addresses compared to an unsigned value).
629    
630    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
631        custom one, because of the following reported problem in Windows:
632    
633          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
634              under Win32.
635          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
636              therefore missing the function definition.
637          - The compiler thus generates a "C" signature for the test function.
638          - The linker fails to find the "C" function.
639          - PCRE fails to configure if asked to do so against libbz2.
640    
641    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
642        messages were output:
643    
644          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
645          rerunning libtoolize, to keep the correct libtool macros in-tree.
646          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
647    
648        I have done both of these things.
649    
650    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
651        most of the time, it *can* run out if it is given a pattern that contains a
652        runaway infinite recursion. I updated the discussion in the pcrestack man
653        page.
654    
655    13. Now that we have gone to the x.xx style of version numbers, the minor
656        version may start with zero. Using 08 or 09 is a bad idea because users
657        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
658        interpreted as invalid octal numbers. I've updated the previous comment in
659        configure.ac, and also added a check that gives an error if 08 or 09 are
660        used.
661    
662    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
663        causing partial matching to fail when the end of the subject matched \W
664        in a UTF-8 pattern where \W was quantified with a minimum of 3.
665    
666    15. There were some discrepancies between the declarations in pcre_internal.h
667        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
668        their definitions. The declarations used "const uschar *" and the
669        definitions used USPTR. Even though USPTR is normally defined as "const
670        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
671        reported that: "This difference in casting confuses some C++ compilers, for
672        example, SunCC recognizes above declarations as different functions and
673        generates broken code for hbpcre." I have changed the declarations to use
674        USPTR.
675    
676    16. GNU libtool is named differently on some systems. The autogen.sh script now
677        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
678        (FreeBSD).
679    
680    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
681        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
682        comment: "Figure out how to create a longlong from a string: strtoll and
683        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
684        instance, but it only takes 2 args instead of 3!"
685    
686    18. A subtle bug concerned with back references has been fixed by a change of
687        specification, with a corresponding code fix. A pattern such as
688        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
689        refers, was giving matches when it shouldn't. For example, xa=xaaa would
690        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
691        same bug. Such groups have to be quantified to be useful, or contained
692        inside another quantified group. (If there's no repetition, the reference
693        can never match.) The problem arises because, having left the group and
694        moved on to the rest of the pattern, a later failure that backtracks into
695        the group uses the captured value from the final iteration of the group
696        rather than the correct earlier one. I have fixed this in PCRE by forcing
697        any group that contains a reference to itself to be an atomic group; that
698        is, there cannot be any backtracking into it once it has completed. This is
699        similar to recursive and subroutine calls.
700    
701    
702    Version 8.00 19-Oct-09
703    ----------------------
704    
705    1.  The table for translating pcre_compile() error codes into POSIX error codes
706        was out-of-date, and there was no check on the pcre_compile() error code
707        being within the table. This could lead to an OK return being given in
708        error.
709    
710    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
711        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
712        in a Windows environment.
713    
714    3.  The pcregrep --count option prints the count for each file even when it is
715        zero, as does GNU grep. However, pcregrep was also printing all files when
716        --files-with-matches was added. Now, when both options are given, it prints
717        counts only for those files that have at least one match. (GNU grep just
718        prints the file name in this circumstance, but including the count seems
719        more useful - otherwise, why use --count?) Also ensured that the
720        combination -clh just lists non-zero counts, with no names.
721    
722    4.  The long form of the pcregrep -F option was incorrectly implemented as
723        --fixed_strings instead of --fixed-strings. This is an incompatible change,
724        but it seems right to fix it, and I didn't think it was worth preserving
725        the old behaviour.
726    
727    5.  The command line items --regex=pattern and --regexp=pattern were not
728        recognized by pcregrep, which required --regex pattern or --regexp pattern
729        (with a space rather than an '='). The man page documented the '=' forms,
730        which are compatible with GNU grep; these now work.
731    
732    6.  No libpcreposix.pc file was created for pkg-config; there was just
733        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
734    
735    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
736        when UCP support is not needed, by modifying the Python script that
737        generates it from Unicode data files. This should not matter if the module
738        is correctly used as a library, but I received one complaint about 50K of
739        unwanted data. My guess is that the person linked everything into his
740        program rather than using a library. Anyway, it does no harm.
741    
742    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
743        was a minimum greater than 1 for a wide character in a possessive
744        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
745        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
746        character. Chaos in the form of incorrect output or a compiling loop could
747        result.
748    
749    9.  The restrictions on what a pattern can contain when partial matching is
750        requested for pcre_exec() have been removed. All patterns can now be
751        partially matched by this function. In addition, if there are at least two
752        slots in the offset vector, the offset of the earliest inspected character
753        for the match and the offset of the end of the subject are set in them when
754        PCRE_ERROR_PARTIAL is returned.
755    
756    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
757        synonymous with PCRE_PARTIAL, for backwards compatibility, and
758        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
759        and may be more useful for multi-segment matching.
760    
761    11. Partial matching with pcre_exec() is now more intuitive. A partial match
762        used to be given if ever the end of the subject was reached; now it is
763        given only if matching could not proceed because another character was
764        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
765        string "Z", which now yields "no match" instead of "partial match". In the
766        case of pcre_dfa_exec(), "no match" is given if every matching path for the
767        final character ended with (*FAIL).
768    
769    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
770        if the pattern had a "must contain" character that was already found in the
771        earlier partial match, unless partial matching was again requested. For
772        example, with the pattern /dog.(body)?/, the "must contain" character is
773        "g". If the first part-match was for the string "dog", restarting with
774        "sbody" failed. This bug has been fixed.
775    
776    13. The string returned by pcre_dfa_exec() after a partial match has been
777        changed so that it starts at the first inspected character rather than the
778        first character of the match. This makes a difference only if the pattern
779        starts with a lookbehind assertion or \b or \B (\K is not supported by
780        pcre_dfa_exec()). It's an incompatible change, but it makes the two
781        matching functions compatible, and I think it's the right thing to do.
782    
783    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
784        so that the demonstration program is easily available in environments where
785        PCRE has not been installed from source.
786    
787    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
788        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
789        library.
790    
791    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
792        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
793        is not the first non-POSIX option to be added. Clearly some people find
794        these options useful.
795    
796    17. If a caller to the POSIX matching function regexec() passes a non-zero
797        value for nmatch with a NULL value for pmatch, the value of
798        nmatch is forced to zero.
799    
800    18. RunGrepTest did not have a test for the availability of the -u option of
801        the diff command, as RunTest does. It now checks in the same way as
802        RunTest, and also checks for the -b option.
803    
804    19. If an odd number of negated classes containing just a single character
805        interposed, within parentheses, between a forward reference to a named
806        subpattern and the definition of the subpattern, compilation crashed with
807        an internal error, complaining that it could not find the referenced
808        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
809        [The bug was that it was starting one character too far in when skipping
810        over the character class, thus treating the ] as data rather than
811        terminating the class. This meant it could skip too much.]
812    
813    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
814        /g option in pcretest when the pattern contains \K, which makes it possible
815        to have an empty string match not at the start, even when the pattern is
816        anchored. Updated pcretest and pcredemo to use this option.
817    
818    21. If the maximum number of capturing subpatterns in a recursion was greater
819        than the maximum at the outer level, the higher number was returned, but
820        with unset values at the outer level. The correct (outer level) value is
821        now given.
822    
823    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
824        PCRE did not set those parentheses (unlike Perl). I have now found a way to
825        make it do so. The string so far is captured, making this feature
826        compatible with Perl.
827    
828    23. The tests have been re-organized, adding tests 11 and 12, to make it
829        possible to check the Perl 5.10 features against Perl 5.10.
830    
831    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
832        pattern matches a fixed length string. PCRE did not allow this; now it
833        does. Neither allows recursion.
834    
835    25. I finally figured out how to implement a request to provide the minimum
836        length of subject string that was needed in order to match a given pattern.
837        (It was back references and recursion that I had previously got hung up
838        on.) This code has now been added to pcre_study(); it finds a lower bound
839        to the length of subject needed. It is not necessarily the greatest lower
840        bound, but using it to avoid searching strings that are too short does give
841        some useful speed-ups. The value is available to calling programs via
842        pcre_fullinfo().
843    
844    26. While implementing 25, I discovered to my embarrassment that pcretest had
845        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
846        study optimizations had never been tested with that matching function.
847        Oops. What is worse, even when it was passed study data, there was a bug in
848        pcre_dfa_exec() that meant it never actually used it. Double oops. There
849        were also very few tests of studied patterns with pcre_dfa_exec().
850    
851    27. If (?| is used to create subpatterns with duplicate numbers, they are now
852        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
853        on the other side of the coin, they are no longer allowed to have different
854        names, because these cannot be distinguished in PCRE, and this has caused
855        confusion. (This is a difference from Perl.)
856    
857    28. When duplicate subpattern names are present (necessarily with different
858        numbers, as required by 27 above), and a test is made by name in a
859        conditional pattern, either for a subpattern having been matched, or for
860        recursion in such a pattern, all the associated numbered subpatterns are
861        tested, and the overall condition is true if the condition is true for any
862        one of them. This is the way Perl works, and is also more like the way
863        testing by number works.
864    
865    
866    Version 7.9 11-Apr-09
867    ---------------------
868    
869    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
870        (pcretest), all targets were linked against these libraries. This included
871        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
872        libraries. This caused unwanted dependencies to be created. This problem
873        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
874        pcretest is linked with readline.
875    
876    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
877        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
878        moved outside it again, because FALSE and TRUE are already defined in AIX,
879        but BOOL is not.
880    
881    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
882        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
883    
884    4.  The pcregrep documentation said spaces were inserted as well as colons (or
885        hyphens) following file names and line numbers when outputting matching
886        lines. This is not true; no spaces are inserted. I have also clarified the
887        wording for the --colour (or --color) option.
888    
889    5.  In pcregrep, when --colour was used with -o, the list of matching strings
890        was not coloured; this is different to GNU grep, so I have changed it to be
891        the same.
892    
893    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
894        each matching line was coloured. Now it goes on to look for further matches
895        of any of the test patterns, which is the same behaviour as GNU grep.
896    
897    7.  A pattern that could match an empty string could cause pcregrep to loop; it
898        doesn't make sense to accept an empty string match in pcregrep, so I have
899        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
900        seems to be how GNU grep behaves.
901    
902    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
903        start or after a newline", because the conditional assertion was not being
904        correctly handled. The rule now is that both the assertion and what follows
905        in the first alternative must satisfy the test.
906    
907    9.  If auto-callout was enabled in a pattern with a conditional group whose
908        condition was an assertion, PCRE could crash during matching, both with
909        pcre_exec() and pcre_dfa_exec().
910    
911    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
912        used for matching.
913    
914    11. Unicode property support in character classes was not working for
915        characters (bytes) greater than 127 when not in UTF-8 mode.
916    
917    12. Added the -M command line option to pcretest.
918    
919    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
920    
921    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
922    
923    16. Added comments and documentation about mis-use of no_arg in the C++
924        wrapper.
925    
926    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
927        from Martin Jerabek that uses macro names for all relevant character and
928        string constants.
929    
930    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
931        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
932        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
933        these, but not everybody uses configure.
934    
935    19. A conditional group that had only one branch was not being correctly
936        recognized as an item that could match an empty string. This meant that an
937        enclosing group might also not be so recognized, causing infinite looping
938        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
939        with the subject "ab", where knowledge that the repeated group can match
940        nothing is needed in order to break the loop.
941    
942    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
943        exec(), but without supplying a callout function, matching went wrong.
944    
945    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
946        leak if the size of the offset vector was greater than 30. When the vector
947        is smaller, the saved offsets during recursion go onto a local stack
948        vector, but for larger vectors malloc() is used. It was failing to free
949        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
950        error, in fact).
951    
952    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
953        heapframe that is used only when UTF-8 support is enabled. This caused no
954        problem, but was untidy.
955    
956    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
957        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
958        included within another project.
959    
960    24. Steven Van Ingelgem's patches to add more options to the CMake support,
961        slightly modified by me:
962    
963          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
964              not building pcregrep.
965    
966          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
967              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
968    
969    25. Forward references, both numeric and by name, in patterns that made use of
970        duplicate group numbers, could behave incorrectly or give incorrect errors,
971        because when scanning forward to find the reference group, PCRE was not
972        taking into account the duplicate group numbers. A pattern such as
973        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
974    
975    26. Changed a few more instances of "const unsigned char *" to USPTR, making
976        the feature of a custom pointer more persuasive (as requested by a user).
977    
978    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
979        pcretest.c, inside #ifndefs, because it seems they are sometimes already
980        pre-defined.
981    
982    28. Added support for (*UTF8) at the start of a pattern.
983    
984    29. Arrange for flags added by the "release type" setting in CMake to be shown
985        in the configuration summary.
986    
987    
988    Version 7.8 05-Sep-08
989    ---------------------
990    
991    1.  Replaced UCP searching code with optimized version as implemented for Ad
992        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
993        stage table and inline lookup instead of a function, giving speed ups of 2
994        to 5 times on some simple patterns that I tested. Permission was given to
995        distribute the MultiStage2.py script that generates the tables (it's not in
996        the tarball, but is in the Subversion repository).
997    
998    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
999        scripts.
1000    
1001    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1002        a group with a zero qualifier. The result of the study could be incorrect,
1003        or the function might crash, depending on the pattern.
1004    
1005    4.  Caseless matching was not working for non-ASCII characters in back
1006        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1007        It now works when Unicode Property Support is available.
1008    
1009    5.  In pcretest, an escape such as \x{de} in the data was always generating
1010        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1011        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1012        truncation.
1013    
1014    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1015    
1016    7.  Added two (int) casts to pcregrep when printing the difference of two
1017        pointers, in case they are 64-bit values.
1018    
1019    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1020        test 2 if it fails.
1021    
1022    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1023        and a #define of that name to empty if it is not externally set. This is to
1024        allow users of MSVC to set it if necessary.
1025    
1026    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1027        the convenience functions in the pcre_get.c source file.
1028    
1029    11. An option change at the start of a pattern that had top-level alternatives
1030        could cause overwriting and/or a crash. This command provoked a crash in
1031        some environments:
1032    
1033          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1034    
1035        This potential security problem was recorded as CVE-2008-2371.
1036    
1037    12. For a pattern where the match had to start at the beginning or immediately
1038        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1039        pcre_dfa_exec() could read past the end of the passed subject if there was
1040        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1041        pcretest so that it places the subject at the end of its malloc-ed buffer.
1042    
1043    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1044        exec() might read past the end of the data buffer in UTF-8 mode.
1045    
1046    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1047        the data contained the byte 0x85 as part of a UTF-8 character within its
1048        first line. This applied both to normal and DFA matching.
1049    
1050    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1051        /^[^d]*?$/8 failed to match "abc".
1052    
1053    16. Added a missing copyright notice to pcrecpp_internal.h.
1054    
1055    17. Make it more clear in the documentation that values returned from
1056        pcre_exec() in ovector are byte offsets, not character counts.
1057    
1058    18. Tidied a few places to stop certain compilers from issuing warnings.
1059    
1060    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1061        supplied by Stefan Weber. I made a further small update for 7.8 because
1062        there is a change of source arrangements: the pcre_searchfuncs.c module is
1063        replaced by pcre_ucd.c.
1064    
1065    
1066    Version 7.7 07-May-08
1067    ---------------------
1068    
1069    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1070        a string to a long long, pretend we don't even have a long long." This is
1071        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1072    
1073    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1074        pre-7.6 versions, which defined a global no_arg variable instead of putting
1075        it in the RE class. (See also #8 below.)
1076    
1077    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1078        Lopes.
1079    
1080    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1081    
1082        (1) The include/exclude patterns were being applied to the whole pathnames
1083            of files, instead of just to the final components.
1084    
1085        (2) If there was more than one level of directory, the subdirectories were
1086            skipped unless they satisfied the include/exclude conditions. This is
1087            inconsistent with GNU grep (and could even be seen as contrary to the
1088            pcregrep specification - which I improved to make it absolutely clear).
1089            The action now is always to scan all levels of directory, and just
1090            apply the include/exclude patterns to regular files.
1091    
1092    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1093        --exclude_dir in the tests to avoid scanning .svn directories.
1094    
1095    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1096        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1097        doesn't support NULs in patterns.
1098    
1099    7.  Added some missing "const"s to declarations of static tables in
1100        pcre_compile.c and pcre_dfa_exec.c.
1101    
1102    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1103        caused by fix #2  above. (Subsequently also a second patch to fix the
1104        first patch. And a third patch - this was a messy problem.)
1105    
1106    9.  Applied Craig's patch to remove the use of push_back().
1107    
1108    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1109        matching function regexec().
1110    
1111    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1112        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1113        references. PCRE supports relative numbers with this syntax (I don't think
1114        Oniguruma does).
1115    
1116    12. Previously, a group with a zero repeat such as (...){0} was completely
1117        omitted from the compiled regex. However, this means that if the group
1118        was called as a subroutine from elsewhere in the pattern, things went wrong
1119        (an internal error was given). Such groups are now left in the compiled
1120        pattern, with a new opcode that causes them to be skipped at execution
1121        time.
1122    
1123    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1124        to the way PCRE behaves:
1125    
1126        (a) A lone ] character is dis-allowed (Perl treats it as data).
1127    
1128        (b) A back reference to an unmatched subpattern matches an empty string
1129            (Perl fails the current match path).
1130    
1131        (c) A data ] in a character class must be notated as \] because if the
1132            first data character in a class is ], it defines an empty class. (In
1133            Perl it is not possible to have an empty class.) The empty class []
1134            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1135            The negative empty class [^] matches any one character, independently
1136            of the DOTALL setting.
1137    
1138    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1139        non-existent subpattern following a character class starting with ']' and
1140        containing () gave an internal compiling error instead of "reference to
1141        non-existent subpattern". Fortunately, when the pattern did exist, the
1142        compiled code was correct. (When scanning forwards to check for the
1143        existencd of the subpattern, it was treating the data ']' as terminating
1144        the class, so got the count wrong. When actually compiling, the reference
1145        was subsequently set up correctly.)
1146    
1147    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1148        it was being rejected as not supported by pcre_dfa_exec(), even though
1149        other assertions are supported. I have made pcre_dfa_exec() support
1150        (*FAIL).
1151    
1152    16. The implementation of 13c above involved the invention of a new opcode,
1153        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1154        cannot be changed at match time, I realized I could make a small
1155        improvement to matching performance by compiling OP_ALLANY instead of
1156        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1157        on the OP_ANY path.
1158    
1159    17. Compiling pcretest on Windows with readline support failed without the
1160        following two fixes: (1) Make the unistd.h include conditional on
1161        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1162    
1163    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1164        ncurses library to be included for pcretest when ReadLine support is
1165        requested, but also to allow for it to be overridden. This patch came from
1166        Daniel Bergström.
1167    
1168    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1169        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1170        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1171        spotting this.
1172    
1173    
1174    Version 7.6 28-Jan-08
1175    ---------------------
1176    
1177    1.  A character class containing a very large number of characters with
1178        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1179        overflow.
1180    
1181    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1182        HAVE_LONG_LONG is not defined.
1183    
1184    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1185        bring them up to date and include new features. This patch includes:
1186    
1187        - Fixed PH's badly added libz and libbz2 support.
1188        - Fixed a problem with static linking.
1189        - Added pcredemo. [But later removed - see 7 below.]
1190        - Fixed dftables problem and added an option.
1191        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1192            HAVE_LONG_LONG.
1193        - Added readline support for pcretest.
1194        - Added an listing of the option settings after cmake has run.
1195    
1196    4.  A user submitted a patch to Makefile that makes it easy to create
1197        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1198        Makefile.am that cause it to include this special target, without
1199        affecting anything else. Note that the same mingw target plus all
1200        the other distribution libraries and programs are now supported
1201        when configuring with CMake (see 6 below) instead of with
1202        Configure/Make.
1203    
1204    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1205        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1206        exported in the Windows port". It has not yet been confirmed that the patch
1207        solves the problem, but it does no harm.
1208    
1209    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1210        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1211        with CMake, and also correct the comment about stack recursion.
1212    
1213    7.  Remove the automatic building of pcredemo from the ./configure system and
1214        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1215        of a program that users should build themselves after PCRE is installed, so
1216        building it automatically is not really right. What is more, it gave
1217        trouble in some build environments.
1218    
1219    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1220    
1221    
1222    Version 7.5 10-Jan-08
1223    ---------------------
1224    
1225    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1226        values in parens when parsing an RE using the C++ wrapper."
1227    
1228    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1229        Characters greater than 255 were excluded from the class instead of being
1230        included.
1231    
1232    3.  The same bug as (2) above applied to negated POSIX classes such as
1233        [:^space:].
1234    
1235    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1236        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1237        I have changed it.
1238    
1239    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1240        first named subpattern) and a construct such as (?&a) would reference the
1241        first named subpattern whose name started with "a" (in other words, the
1242        length check was missing). Both these problems are fixed. "Subpattern name
1243        expected" is now given for (?&) (a zero-length name), and this patch also
1244        makes it give the same error for \k'' (previously it complained that that
1245        was a reference to a non-existent subpattern).
1246    
1247    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1248        this is right because (?- can be followed by option settings as well as by
1249        digits. I have, however, made the messages clearer.
1250    
1251    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1252        than the number used in the conditional) now cause a compile-time error.
1253        This is actually not compatible with Perl, which accepts such patterns, but
1254        treats the conditional as always being FALSE (as PCRE used to), but it
1255        seems to me that giving a diagnostic is better.
1256    
1257    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1258        and messages.
1259    
1260    9.  Fix two occurrences of "backslash" in comments that should have been
1261        "backspace".
1262    
1263    10. Remove two redundant lines of code that can never be obeyed (their function
1264        was moved elsewhere).
1265    
1266    11. The program that makes PCRE's Unicode character property table had a bug
1267        which caused it to generate incorrect table entries for sequences of
1268        characters that have the same character type, but are in different scripts.
1269        It amalgamated them into a single range, with the script of the first of
1270        them. In other words, some characters were in the wrong script. There were
1271        thirteen such cases, affecting characters in the following ranges:
1272    
1273          U+002b0 - U+002c1
1274          U+0060c - U+0060d
1275          U+0061e - U+00612
1276          U+0064b - U+0065e
1277          U+0074d - U+0076d
1278          U+01800 - U+01805
1279          U+01d00 - U+01d77
1280          U+01d9b - U+01dbf
1281          U+0200b - U+0200f
1282          U+030fc - U+030fe
1283          U+03260 - U+0327f
1284          U+0fb46 - U+0fbb1
1285          U+10450 - U+1049d
1286    
1287    12. The -o option (show only the matching part of a line) for pcregrep was not
1288        compatible with GNU grep in that, if there was more than one match in a
1289        line, it showed only the first of them. It now behaves in the same way as
1290        GNU grep.
1291    
1292    13. If the -o and -v options were combined for pcregrep, it printed a blank
1293        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1294        does the same. The return code can be used to tell if there were any
1295        non-matching lines.
1296    
1297    14. Added --file-offsets and --line-offsets to pcregrep.
1298    
1299    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1300        infinitely looping recursion. The bug was that positive lookaheads were not
1301        being skipped when checking for a possible empty match (negative lookaheads
1302        and both kinds of lookbehind were skipped).
1303    
1304    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1305        inclusion of <windows.h> to before rather than after the definition of
1306        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1307    
1308    17. Specifying a possessive quantifier with a specific limit for a Unicode
1309        character property caused pcre_compile() to compile bad code, which led at
1310        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1311        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1312        caused the error; without that there was no problem.
1313    
1314    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1315    
1316    19. Added --enable-pcretest-libreadline.
1317    
1318    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1319        RE::GlobalReplace(). As a result, the number of replacements returned was
1320        double what it should be. I removed one of the increments, but Craig sent a
1321        later patch that removed the other one (the right fix) and added unit tests
1322        that check the return values (which was not done before).
1323    
1324    21. Several CMake things:
1325    
1326        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1327            the names libpcre and libpcreposix, not just pcre and pcreposix.
1328    
1329        (2) The above change means that pcretest and pcregrep are now correctly
1330            linked with the newly-built libraries, not previously installed ones.
1331    
1332        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1333    
1334    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1335        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1336        UTF-8 newline character). The key issue is that the pattern starts .*;
1337        this means that the match must be either at the beginning, or after a
1338        newline. The bug was in the code for advancing after a failed match and
1339        checking that the new position followed a newline. It was not taking
1340        account of UTF-8 characters correctly.
1341    
1342    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1343        character classes. PCRE was not treating the sequence [:...:] as a
1344        character class unless the ... were all letters. Perl, however, seems to
1345        allow any characters between [: and :], though of course it rejects as
1346        unknown any "names" that contain non-letters, because all the known class
1347        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1348        for example, whereas PCRE did not - it did not recognize a POSIX character
1349        class. This seemed a bit dangerous, so the code has been changed to be
1350        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1351        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1352        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1353        Perl does, and where it didn't before.
1354    
1355    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1356        Windows environments %n is disabled by default.
1357    
1358    
1359    Version 7.4 21-Sep-07
1360    ---------------------
1361    
1362    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1363        means that a class such as [\s] counted as "explicit reference to CR or
1364        LF". That isn't really right - the whole point of the change was to try to
1365        help when there was an actual mention of one of the two characters. So now
1366        the change happens only if \r or \n (or a literal CR or LF) character is
1367        encountered.
1368    
1369    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1370        of both had grown to the point where there were only 3 bits left.
1371        Fortunately, there was spare space in the data structure, and so I have
1372        moved the internal flags into a new 16-bit field to free up more option
1373        bits.
1374    
1375    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1376        but did not set the internal JCHANGED flag - either of these is enough to
1377        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1378        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1379        start sets both bits.
1380    
1381    4.  Added options (at build time, compile time, exec time) to change \R from
1382        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1383    
1384    5.  doc/pcresyntax.html was missing from the distribution.
1385    
1386    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1387        compatibility, even though it is no longer used.
1388    
1389    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1390        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1391        windows.h file is present (where different names are used). [This was
1392        reversed later after testing - see 16 below.]
1393    
1394    8.  Changed all #include <config.h> to #include "config.h". There were also
1395        some further <pcre.h> cases that I changed to "pcre.h".
1396    
1397    9.  When pcregrep was used with the --colour option, it missed the line ending
1398        sequence off the lines that it output.
1399    
1400    10. It was pointed out to me that arrays of string pointers cause lots of
1401        relocations when a shared library is dynamically loaded. A technique of
1402        using a single long string with a table of offsets can drastically reduce
1403        these. I have refactored PCRE in four places to do this. The result is
1404        dramatic:
1405    
1406          Originally:                          290
1407          After changing UCP table:            187
1408          After changing error message table:   43
1409          After changing table of "verbs"       36
1410          After changing table of Posix names   22
1411    
1412        Thanks to the folks working on Gregex for glib for this insight.
1413    
1414    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1415        unicode-properties was also set.
1416    
1417    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1418    
1419    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1420        checked only for CRLF.
1421    
1422    14. Added casts to pcretest.c to avoid compiler warnings.
1423    
1424    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1425    
1426    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1427        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1428        entirely. This removes changes made in 7 above.
1429    
1430    17. The CMake files have been updated, and there is now more information about
1431        building with CMake in the NON-UNIX-USE document.
1432    
1433    
1434    Version 7.3 28-Aug-07
1435    ---------------------
1436    
1437     1. In the rejigging of the build system that eventually resulted in 7.1, the
1438        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1439        brackets there is not right, since it causes compilers to look for an
1440        installed pcre.h, not the version that is in the source that is being
1441        compiled (which of course may be different). I have changed it back to:
1442    
1443          #include "pcre.h"
1444    
1445        I have a vague recollection that the change was concerned with compiling in
1446        different directories, but in the new build system, that is taken care of
1447        by the VPATH setting the Makefile.
1448    
1449     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1450        when the subject happened to end in the byte 0x85 (e.g. if the last
1451        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1452        characters but of course it shouldn't be taken as a newline when it is part
1453        of another character. The bug was that, for an unlimited repeat of . in
1454        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1455        characters when looking for a newline.
1456    
1457     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1458    
1459     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1460        in debug output.
1461    
1462     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1463        long printing in the pcrecpp unittest when running under MinGW.
1464    
1465     6. ESC_K was left out of the EBCDIC table.
1466    
1467     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1468        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1469        limit also applies to "virtual nesting" when a pattern is recursive, and in
1470        this case 1000 isn't so big. I have been able to remove this limit at the
1471        expense of backing off one optimization in certain circumstances. Normally,
1472        when pcre_exec() would call its internal match() function recursively and
1473        immediately return the result unconditionally, it uses a "tail recursion"
1474        feature to save stack. However, when a subpattern that can match an empty
1475        string has an unlimited repetition quantifier, it no longer makes this
1476        optimization. That gives it a stack frame in which to save the data for
1477        checking that an empty string has been matched. Previously this was taken
1478        from the 1000-entry workspace that had been reserved. So now there is no
1479        explicit limit, but more stack is used.
1480    
1481     8. Applied Daniel's patches to solve problems with the import/export magic
1482        syntax that is required for Windows, and which was going wrong for the
1483        pcreposix and pcrecpp parts of the library. These were overlooked when this
1484        problem was solved for the main library.
1485    
1486     9. There were some crude static tests to avoid integer overflow when computing
1487        the size of patterns that contain repeated groups with explicit upper
1488        limits. As the maximum quantifier is 65535, the maximum group length was
1489        set at 30,000 so that the product of these two numbers did not overflow a
1490        32-bit integer. However, it turns out that people want to use groups that
1491        are longer than 30,000 bytes (though not repeat them that many times).
1492        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1493        made it possible to implement the integer overflow checks in a much more
1494        dynamic way, which I have now done. The artificial limitation on group
1495        length has been removed - we now have only the limit on the total length of
1496        the compiled pattern, which depends on the LINK_SIZE setting.
1497    
1498    10. Fixed a bug in the documentation for get/copy named substring when
1499        duplicate names are permitted. If none of the named substrings are set, the
1500        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1501        empty string.
1502    
1503    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1504        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1505        because the ] is interpreted as the first data character and the
1506        terminating ] is not found. PCRE has been made compatible with Perl in this
1507        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1508        cause memory overwriting.
1509    
1510    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1511        string has been matched (to stop an infinite loop). It was not recognizing
1512        a conditional subpattern that could match an empty string if that
1513        subpattern was within another subpattern. For example, it looped when
1514        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1515        condition was not nested. This bug has been fixed.
1516    
1517    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1518        past the start of the subject in the presence of bytes with the top bit
1519        set, for example "\x8aBCD".
1520    
1521    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1522        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1523    
1524    14. Optimized (?!) to (*FAIL).
1525    
1526    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1527        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1528        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1529        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1530        does: it's just the validity check that is more restrictive.
1531    
1532    16. Inserted checks for integer overflows during escape sequence (backslash)
1533        processing, and also fixed erroneous offset values for syntax errors during
1534        backslash processing.
1535    
1536    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1537        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1538    
1539    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1540        caused an overrun.
1541    
1542    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1543        something other than just ASCII characters) inside a group that had an
1544        unlimited repeat caused a loop at compile time (while checking to see
1545        whether the group could match an empty string).
1546    
1547    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1548        [\P{Any}] did so. (Error in the code for printing property names.)
1549    
1550    21. An orphan \E inside a character class could cause a crash.
1551    
1552    22. A repeated capturing bracket such as (A)? could cause a wild memory
1553        reference during compilation.
1554    
1555    23. There are several functions in pcre_compile() that scan along a compiled
1556        expression for various reasons (e.g. to see if it's fixed length for look
1557        behind). There were bugs in these functions when a repeated \p or \P was
1558        present in the pattern. These operators have additional parameters compared
1559        with \d, etc, and these were not being taken into account when moving along
1560        the compiled data. Specifically:
1561    
1562        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1563            length.
1564    
1565        (b) An item such as \pL+ within a repeated group could cause crashes or
1566            loops.
1567    
1568        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1569            "reference to non-existent subpattern" error.
1570    
1571        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1572    
1573    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1574        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1575    
1576    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1577    
1578    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1579        character were causing crashes (broken optimization).
1580    
1581    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1582        \p or \P) caused a compile-time loop.
1583    
1584    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1585        break. For example, the unstudied pattern [\r\n]A does not match the string
1586        "\r\nA" because change 7.0/46 below moves the current point on by two
1587        characters after failing to match at the start. However, the pattern \nA
1588        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1589        the same is true. There doesn't seem any very clean way out of this, but
1590        what I have chosen to do makes the common cases work: PCRE now takes note
1591        of whether there can be an explicit match for \r or \n anywhere in the
1592        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1593        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1594        pattern has explicit CR or LF references.
1595    
1596    29. Added (*CR) etc for changing newline setting at start of pattern.
1597    
1598    
1599    Version 7.2 19-Jun-07
1600  ---------------------  ---------------------
1601    
1602   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 22  Version 7.2 01-May-07 Line 1617  Version 7.2 01-May-07
1617      a small improvement under Linux. However, it saves one field in the frame      a small improvement under Linux. However, it saves one field in the frame
1618      in all cases.      in all cases.
1619    
1620     6. Added more features from the forthcoming Perl 5.10:
1621    
1622        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1623            recursion call. It refers to the nth most recently opened parentheses.
1624    
1625        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1626            to be opened parentheses.
1627    
1628        (c) Conditions that refer to capturing parentheses can be specified
1629            relatively, for example, (?(-2)... or (?(+3)...
1630    
1631        (d) \K resets the start of the current match so that everything before
1632            is not part of it.
1633    
1634        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1635    
1636        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1637            reference syntax.
1638    
1639        (g) (?| introduces a group in which the numbering of parentheses in each
1640            alternative starts with the same number.
1641    
1642        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1643    
1644     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1645        PCRE_INFO_JCHANGED.
1646    
1647     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1648        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1649        for detecting groups that can match an empty string.
1650    
1651     9. A pattern with a very large number of alternatives (more than several
1652        hundred) was running out of internal workspace during the pre-compile
1653        phase, where pcre_compile() figures out how much memory will be needed. A
1654        bit of new cunning has reduced the workspace needed for groups with
1655        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1656        workspace instead of running out of the 4096 that are available.
1657    
1658    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1659    
1660    11. Applied patch from Google to remove an optimization that didn't quite work.
1661        The report of the bug said:
1662    
1663          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1664          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1665          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1666    
1667    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1668        it matched the wrong number of bytes.
1669    
1670    
1671  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07
1672  ---------------------  ---------------------

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