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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.13 30-Apr-2011
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
8    
9    2.  Two minor typos in pcre_internal.h have been fixed.
10    
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
14    
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
23    
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
28    
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
34    
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
38    
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
46    
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55    
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
59    
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
62    
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
68    
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
72    
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
77    
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collections of tests with and without
83        study enabled, and thereby test pcre_study() more easily. All the standard
84        tests are now run with and without -s (but some patterns can be marked as
85        "never study" - see 20 below).
86    
87    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88        restoration of the capturing data to the outer values was not happening
89        correctly.
90    
91    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93        pattern had matched an empty string, and so incorrectly returned a no
94        match.
95    
96    17. There was optimizing code for the last branch of non-capturing parentheses,
97        and also for the obeyed branch of a conditional subexpression, which used
98        tail recursion to cut down on stack usage. Unfortunately, not that there is
99        the possibility of (*THEN) occurring in these branches, tail recursion is
100        no longer possible because the return has to be checked for (*THEN). These
101        two optimizations have therefore been removed.
102    
103    18. If a pattern containing \R was studied, it was assumed that \R always
104        matched two bytes, thus causing the minimum subject length to be
105        incorrectly computed because \R can also match just one byte.
106    
107    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108        was incorrectly computed.
109    
110    20. If /S is present twice on a test pattern in pcretest input, it *disables*
111        studying, thereby overriding the use of -s on the command line. This is
112        necessary for one or two tests to keep the output identical in both cases.
113    
114    21. When (*ACCEPT) was used in an assertion that matched an empty string and
115        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
116    
117    22. When an atomic group that contained a capturing parenthesis was
118        successfully matched, but the branch in which it appeared failed, the
119        capturing was not being forgotten if a higher numbered group was later
120        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121        group 1 to "a", when in fact it should be unset. This applied to multi-
122        branched capturing and non-capturing groups, repeated or not, and also to
123        positive assertions (capturing in negative assertions is not well defined
124        in PCRE) and also to nested atomic groups.
125    
126    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127        subject after a captured substring (to make it easier to tell which of a
128        number of identical substrings has been captured).
129    
130    24. The way atomic groups are processed by pcre_exec() has been changed so that
131        if they are repeated, backtracking one repetition now resets captured
132        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134        "aaa". Previously, it would have been "a". As part of this code
135        refactoring, the way recursive calls are handled has also been changed.
136    
137    24. If an assertion condition captured any substrings, they were not passed
138        back unless some other capturing happened later. For example, if
139        (?(?=(a))a) was matched against "a", no capturing was returned.
140    
141    25. When studying a pattern that contained subroutine calls or assertions,
142        the code for finding the minimum length of a possible match was handling
143        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
144        group 1 called group 2 while simultaneously a separate group 2 called group
145        1). A stack overflow occurred in this case. I have fixed this by limiting
146        the recursion depth to 10.
147    
148    26. Updated RunTest.bat in the distribution to the version supplied by Tom
149        Fortmann. This supports explicit test numbers on the command line, and has
150        argument validation and error reporting.
151    
152    27. An instance of \X with an unlimited repeat could fail if at any point the
153        first character it looked at was a mark character.
154    
155    28. Some minor code refactoring concerning Unicode properties and scripts
156        should reduce the stack requirement of match() slightly.
157    
158    29. Added the '=' option to pcretest to check the setting of unused capturing
159        slots at the end of the pattern, which are documented as being -1, but are
160        not included in the return count.
161    
162    30. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
163        compiled something random. Now it gives a compile-time error (as does
164        Perl).
165    
166    31. A *MARK encountered during the processing of a positive assertion is now
167        recorded and passed back (compatible with Perl).
168    
169    32. If --only-matching or --colour was set on a pcregrep call whose pattern
170        had alternative anchored branches, the search for a second match in a line
171        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
172        matched the line "0102" twice. The same bug affected patterns that started
173        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
174        twice.
175    
176    33. Previously, PCRE did not allow quantification of assertions. However, Perl
177        does, and because of capturing effects, quantifying parenthesized
178        assertions may at times be useful. Quantifiers are now allowed for
179        parenthesized assertions.
180    
181    34. A minor code tidy in pcre_compile() when checking options for \R usage.
182    
183    35. \g was being checked for fancy things in a character class, when it should
184        just be a literal "g".
185    
186    36. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
187        appearance of a nested POSIX class supersedes an apparent external class.
188        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
189        unescaped square brackets may also appear as part of class names. For
190        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
191        more like Perl.
192    
193    37. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
194        was because it thought it was \N{name}, which is not supported).
195    
196    38. Add minix to OS list not supporting the -S option in pcretest.
197    
198    39. PCRE tries to detect cases of infinite recursion at compile time, but it
199        cannot analyze patterns in sufficient detail to catch mutual recursions
200        such as ((?1))((?2)). There is now a runtime test that gives an error if a
201        subgroup is called recursively as a subpattern for a second time at the
202        same position in the subject string. In previous releases this might have
203        been caught by the recursion limit, or it might have run out of stack.
204    
205    40. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
206        happen only once. PCRE was, however incorrectly giving a compile time error
207        "recursive call could loop indefinitely" because it cannot analyze the
208        pattern in sufficient detail. The compile time test no longer happens when
209        PCRE is compiling a conditional subpattern, but actual runaway loops are
210        now caught at runtime (see 39 above).
211    
212    41. It seems that Perl allows any characters other than a closing parenthesis
213        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
214        has been changed to be the same.
215    
216    42. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
217        as not to get warnings when autogen.sh is called. Also changed
218        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
219    
220    43. To help people who use pcregrep to scan files containing exceedingly long
221        lines, the following changes have been made:
222    
223        (a) The default value of the buffer size parameter has been increased from
224            8K to 20K. (A buffer three times this size is actually used.)
225    
226        (b) The default can be changed by ./configure --with-pcregrep-bufsiz when
227            PCRE is built.
228    
229        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
230            to be set at run time.
231    
232        (d) Numerical values in pcregrep options can be followed by K or M, for
233            example --buffer-size=50K.
234    
235        (e) If a line being scanned overflows pcregrep's buffer, an error is now
236            given and the return code is set to 2.
237    
238    44. Add a pointer to the latest mark to the callout data block.
239    
240    45. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
241        partial match of an empty string instead of no match. This was specific to
242        the use of ".".
243    
244    46. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
245        complete match instead of a partial match. This bug was dependent on both
246        the PCRE_UTF8 and PCRE_DOTALL options being set.
247    
248    
249    Version 8.12 15-Jan-2011
250    ------------------------
251    
252    1.  Fixed some typos in the markup of the man pages, and wrote a script that
253        checks for such things as part of the documentation building process.
254    
255    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
256        --match-limit and --recursion-limit options (added for 8.11). In
257        particular, this made one of the standard tests fail. (The integer value
258        went into the wrong half of a long int.)
259    
260    3.  If the --colour option was given to pcregrep with -v (invert match), it
261        did strange things, either producing crazy output, or crashing. It should,
262        of course, ignore a request for colour when reporting lines that do not
263        match.
264    
265    4.  Another pcregrep bug caused similar problems if --colour was specified with
266        -M (multiline) and the pattern match finished with a line ending.
267    
268    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
269        matched in multiline mode, the following line was shown as part of the
270        match. This seems wrong, so I have changed it.
271    
272    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
273        the check for further matches in the same line (so they could be coloured)
274        to overrun the end of the current line. If another match was found, it was
275        incorrectly shown (and then shown again when found in the next line).
276    
277    7.  If pcregrep was compiled under Windows, there was a reference to the
278        function pcregrep_exit() before it was defined. I am assuming this was
279        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
280        reported by a user. I've moved the definition above the reference.
281    
282    
283    Version 8.11 10-Dec-2010
284    ------------------------
285    
286    1.  (*THEN) was not working properly if there were untried alternatives prior
287        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
288        backtracked to try for "b" instead of moving to the next alternative branch
289        at the same level (in this case, to look for "c"). The Perl documentation
290        is clear that when (*THEN) is backtracked onto, it goes to the "next
291        alternative in the innermost enclosing group".
292    
293    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
294        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
295        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
296        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
297        (*THEN).
298    
299    3.  If \s appeared in a character class, it removed the VT character from
300        the class, even if it had been included by some previous item, for example
301        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
302        of \s, but is part of the POSIX "space" class.)
303    
304    4.  A partial match never returns an empty string (because you can always
305        match an empty string at the end of the subject); however the checking for
306        an empty string was starting at the "start of match" point. This has been
307        changed to the "earliest inspected character" point, because the returned
308        data for a partial match starts at this character. This means that, for
309        example, /(?<=abc)def/ gives a partial match for the subject "abc"
310        (previously it gave "no match").
311    
312    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
313        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
314        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
315        has an implication that the given string is incomplete (because a partial
316        match is preferred over a full match). For this reason, these items now
317        give a partial match in this situation. [Aside: previously, the one case
318        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
319        match rather than a full match, which was wrong by the old rules, but is
320        now correct.]
321    
322    6.  There was a bug in the handling of #-introduced comments, recognized when
323        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
324        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
325        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
326        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
327        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
328        places in pcre_compile().
329    
330    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
331        comments when looking ahead for named forward references to subpatterns,
332        the only newline sequence it recognized was NL. It now handles newlines
333        according to the set newline convention.
334    
335    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
336        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
337        cater for a lack of strerror(). These oversights have been fixed.
338    
339    9.  Added --match-limit and --recursion-limit to pcregrep.
340    
341    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
342    
343    11. When the -o option was used, pcregrep was setting a return code of 1, even
344        when matches were found, and --line-buffered was not being honoured.
345    
346    12. Added an optional parentheses number to the -o and --only-matching options
347        of pcregrep.
348    
349    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
350        can match an empty string. The code to do it in pcretest and pcredemo
351        needed fixing:
352    
353        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
354            only one byte after an empty string match just before CRLF (this case
355            just got forgotten; "any" and "anycrlf" were OK).
356    
357        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
358            mode when an empty string match preceded an ASCII character followed by
359            a non-ASCII character. (The code for advancing by one character rather
360            than one byte was nonsense.)
361    
362        (c) The pcredemo.c sample program did not have any code at all to handle
363            the cases when CRLF is a valid newline sequence.
364    
365    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
366        as a starting offset was within the subject string. There is now a new
367        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
368        negative or greater than the length of the string. In order to test this,
369        pcretest is extended to allow the setting of negative starting offsets.
370    
371    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
372        starting offset points to the beginning of a UTF-8 character was
373        unnecessarily clumsy. I tidied it up.
374    
375    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
376        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
377    
378    17. Nobody had reported that the --include_dir option, which was added in
379        release 7.7 should have been called --include-dir (hyphen, not underscore)
380        for compatibility with GNU grep. I have changed it to --include-dir, but
381        left --include_dir as an undocumented synonym, and the same for
382        --exclude-dir, though that is not available in GNU grep, at least as of
383        release 2.5.4.
384    
385    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
386        characters from a string of bytes) have been redefined so as not to use
387        loops, in order to improve performance in some environments. At the same
388        time, I abstracted some of the common code into auxiliary macros to save
389        repetition (this should not affect the compiled code).
390    
391    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
392        compile-time error is now given if \c is not followed by an ASCII
393        character, that is, a byte less than 128. (In EBCDIC mode, the code is
394        different, and any byte value is allowed.)
395    
396    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
397        START_OPTIMIZE option, which is now allowed at compile time - but just
398        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
399        to pcregrep and other applications that have no direct access to PCRE
400        options. The new /Y option in pcretest sets this option when calling
401        pcre_compile().
402    
403    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
404        back references. Groups containing recursive back references were forced to
405        be atomic by that change, but in the case of named groups, the amount of
406        memory required was incorrectly computed, leading to "Failed: internal
407        error: code overflow". This has been fixed.
408    
409    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
410        pcretest.c, to avoid build problems in some Borland environments.
411    
412    
413    Version 8.10 25-Jun-2010
414    ------------------------
415    
416    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
417        THEN.
418    
419    2.  (*ACCEPT) was not working when inside an atomic group.
420    
421    3.  Inside a character class, \B is treated as a literal by default, but
422        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
423        causes the error). The code is unchanged, but I tidied the documentation.
424    
425    4.  Inside a character class, PCRE always treated \R and \X as literals,
426        whereas Perl faults them if its -w option is set. I have changed PCRE so
427        that it faults them when PCRE_EXTRA is set.
428    
429    5.  Added support for \N, which always matches any character other than
430        newline. (It is the same as "." when PCRE_DOTALL is not set.)
431    
432    6.  When compiling pcregrep with newer versions of gcc which may have
433        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
434        declared with attribute warn_unused_result" were given. Just casting the
435        result to (void) does not stop the warnings; a more elaborate fudge is
436        needed. I've used a macro to implement this.
437    
438    7.  Minor change to pcretest.c to avoid a compiler warning.
439    
440    8.  Added four artifical Unicode properties to help with an option to make
441        \s etc use properties (see next item). The new properties are: Xan
442        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
443    
444    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
445        use Unicode properties. (*UCP) at the start of a pattern can be used to set
446        this option. Modified pcretest to add /W to test this facility. Added
447        REG_UCP to make it available via the POSIX interface.
448    
449    10. Added --line-buffered to pcregrep.
450    
451    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
452        studied, and the match started with a letter with a code point greater than
453        127 whose first byte was different to the first byte of the other case of
454        the letter, the other case of this starting letter was not recognized
455        (#976).
456    
457    12. If a pattern that was studied started with a repeated Unicode property
458        test, for example, \p{Nd}+, there was the theoretical possibility of
459        setting up an incorrect bitmap of starting bytes, but fortunately it could
460        not have actually happened in practice until change 8 above was made (it
461        added property types that matched character-matching opcodes).
462    
463    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
464        possible starting bytes for non-anchored patterns.
465    
466    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
467        \R, and also a number of cases that involve Unicode properties, both
468        explicit and implicit when PCRE_UCP is set.
469    
470    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
471        input, it could crash or give wrong results if characters with values
472        greater than 0xc0 were present in the subject string. (Detail: it assumed
473        UTF-8 input when processing these items.)
474    
475    16. Added a lot of (int) casts to avoid compiler warnings in systems where
476        size_t is 64-bit (#991).
477    
478    17. Added a check for running out of memory when PCRE is compiled with
479        --disable-stack-for-recursion (#990).
480    
481    18. If the last data line in a file for pcretest does not have a newline on
482        the end, a newline was missing in the output.
483    
484    19. The default pcre_chartables.c file recognizes only ASCII characters (values
485        less than 128) in its various bitmaps. However, there is a facility for
486        generating tables according to the current locale when PCRE is compiled. It
487        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
488        characters, are recognized by isspace() and therefore were getting set in
489        these tables, and indeed these tables seem to approximate to ISO 8859. This
490        caused a problem in UTF-8 mode when pcre_study() was used to create a list
491        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
492        which of course cannot start UTF-8 characters. I have changed the code so
493        that only real ASCII characters (less than 128) and the correct starting
494        bytes for UTF-8 encodings are set for characters greater than 127 when in
495        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
496        altogether.)
497    
498    20. Added the /T option to pcretest so as to be able to run tests with non-
499        standard character tables, thus making it possible to include the tests
500        used for 19 above in the standard set of tests.
501    
502    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
503        reference to a subpattern the other side of a comment that contains an
504        opening parenthesis caused either an internal compiling error, or a
505        reference to the wrong subpattern.
506    
507    
508    Version 8.02 19-Mar-2010
509    ------------------------
510    
511    1.  The Unicode data tables have been updated to Unicode 5.2.0.
512    
513    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
514        configured.
515    
516    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
517        original author of that file, following a query about its status.
518    
519    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
520        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
521    
522    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
523        quantifier applied to a forward-referencing subroutine call, could compile
524        incorrect code or give the error "internal error: previously-checked
525        referenced subpattern not found".
526    
527    6.  Both MS Visual Studio and Symbian OS have problems with initializing
528        variables to point to external functions. For these systems, therefore,
529        pcre_malloc etc. are now initialized to local functions that call the
530        relevant global functions.
531    
532    7.  There were two entries missing in the vectors called coptable and poptable
533        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
534        I've fixed the data, and added a kludgy way of testing at compile time that
535        the lengths are correct (equal to the number of opcodes).
536    
537    8.  Following on from 7, I added a similar kludge to check the length of the
538        eint vector in pcreposix.c.
539    
540    9.  Error texts for pcre_compile() are held as one long string to avoid too
541        much relocation at load time. To find a text, the string is searched,
542        counting zeros. There was no check for running off the end of the string,
543        which could happen if a new error number was added without updating the
544        string.
545    
546    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
547    
548    11. \K was not working if it appeared in an atomic group or in a group that
549        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
550        \K is "not well defined" if used in an assertion. PCRE now accepts it if
551        the assertion is positive, but not if it is negative.
552    
553    12. Change 11 fortuitously reduced the size of the stack frame used in the
554        "match()" function of pcre_exec.c by one pointer. Forthcoming
555        implementation of support for (*MARK) will need an extra pointer on the
556        stack; I have reserved it now, so that the stack frame size does not
557        decrease.
558    
559    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
560        item in branch that calls a recursion is a subroutine call - as in the
561        second branch in the above example - was incorrectly given the compile-
562        time error "recursive call could loop indefinitely" because pcre_compile()
563        was not correctly checking the subroutine for matching a non-empty string.
564    
565    14. The checks for overrunning compiling workspace could trigger after an
566        overrun had occurred. This is a "should never occur" error, but it can be
567        triggered by pathological patterns such as hundreds of nested parentheses.
568        The checks now trigger 100 bytes before the end of the workspace.
569    
570    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
571    
572    
573    Version 8.01 19-Jan-2010
574    ------------------------
575    
576    1.  If a pattern contained a conditional subpattern with only one branch (in
577        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
578        computed the wrong minimum data length (which is of course zero for such
579        subpatterns). This could cause incorrect "no match" results.
580    
581    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
582        the pattern is reset in the first branch, pcre_compile() failed with
583        "internal error: code overflow at offset...". This happened only when
584        the reset was to the original external option setting. (An optimization
585        abstracts leading options settings into an external setting, which was the
586        cause of this.)
587    
588    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
589        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
590        assertion pattern did not match (meaning that the assertion was true), it
591        was incorrectly treated as false if the SKIP had been reached during the
592        matching. This also applied to assertions used as conditions.
593    
594    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
595        assertion subpattern, including such a pattern used as a condition,
596        unpredictable results occurred, instead of the error return
597        PCRE_ERROR_DFA_UITEM.
598    
599    5.  The C++ GlobalReplace function was not working like Perl for the special
600        situation when an empty string is matched. It now does the fancy magic
601        stuff that is necessary.
602    
603    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
604        removed. (These were left over from very, very early versions of PCRE.)
605    
606    7.  Some cosmetic changes to the code to make life easier when compiling it
607        as part of something else:
608    
609        (a) Change DEBUG to PCRE_DEBUG.
610    
611        (b) In pcre_compile(), rename the member of the "branch_chain" structure
612            called "current" as "current_branch", to prevent a collision with the
613            Linux macro when compiled as a kernel module.
614    
615        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
616            prevent a collision with the Linux macro when compiled as a kernel
617            module.
618    
619    8.  In pcre_compile() there are some checks for integer overflows that used to
620        cast potentially large values to (double). This has been changed to that
621        when building, a check for int64_t is made, and if it is found, it is used
622        instead, thus avoiding the use of floating point arithmetic. (There is no
623        other use of FP in PCRE.) If int64_t is not found, the fallback is to
624        double.
625    
626    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
627        2005 (difference between two addresses compared to an unsigned value).
628    
629    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
630        custom one, because of the following reported problem in Windows:
631    
632          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
633              under Win32.
634          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
635              therefore missing the function definition.
636          - The compiler thus generates a "C" signature for the test function.
637          - The linker fails to find the "C" function.
638          - PCRE fails to configure if asked to do so against libbz2.
639    
640    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
641        messages were output:
642    
643          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
644          rerunning libtoolize, to keep the correct libtool macros in-tree.
645          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
646    
647        I have done both of these things.
648    
649    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
650        most of the time, it *can* run out if it is given a pattern that contains a
651        runaway infinite recursion. I updated the discussion in the pcrestack man
652        page.
653    
654    13. Now that we have gone to the x.xx style of version numbers, the minor
655        version may start with zero. Using 08 or 09 is a bad idea because users
656        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
657        interpreted as invalid octal numbers. I've updated the previous comment in
658        configure.ac, and also added a check that gives an error if 08 or 09 are
659        used.
660    
661    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
662        causing partial matching to fail when the end of the subject matched \W
663        in a UTF-8 pattern where \W was quantified with a minimum of 3.
664    
665    15. There were some discrepancies between the declarations in pcre_internal.h
666        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
667        their definitions. The declarations used "const uschar *" and the
668        definitions used USPTR. Even though USPTR is normally defined as "const
669        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
670        reported that: "This difference in casting confuses some C++ compilers, for
671        example, SunCC recognizes above declarations as different functions and
672        generates broken code for hbpcre." I have changed the declarations to use
673        USPTR.
674    
675    16. GNU libtool is named differently on some systems. The autogen.sh script now
676        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
677        (FreeBSD).
678    
679    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
680        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
681        comment: "Figure out how to create a longlong from a string: strtoll and
682        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
683        instance, but it only takes 2 args instead of 3!"
684    
685    18. A subtle bug concerned with back references has been fixed by a change of
686        specification, with a corresponding code fix. A pattern such as
687        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
688        refers, was giving matches when it shouldn't. For example, xa=xaaa would
689        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
690        same bug. Such groups have to be quantified to be useful, or contained
691        inside another quantified group. (If there's no repetition, the reference
692        can never match.) The problem arises because, having left the group and
693        moved on to the rest of the pattern, a later failure that backtracks into
694        the group uses the captured value from the final iteration of the group
695        rather than the correct earlier one. I have fixed this in PCRE by forcing
696        any group that contains a reference to itself to be an atomic group; that
697        is, there cannot be any backtracking into it once it has completed. This is
698        similar to recursive and subroutine calls.
699    
700    
701    Version 8.00 19-Oct-09
702    ----------------------
703    
704    1.  The table for translating pcre_compile() error codes into POSIX error codes
705        was out-of-date, and there was no check on the pcre_compile() error code
706        being within the table. This could lead to an OK return being given in
707        error.
708    
709    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
710        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
711        in a Windows environment.
712    
713    3.  The pcregrep --count option prints the count for each file even when it is
714        zero, as does GNU grep. However, pcregrep was also printing all files when
715        --files-with-matches was added. Now, when both options are given, it prints
716        counts only for those files that have at least one match. (GNU grep just
717        prints the file name in this circumstance, but including the count seems
718        more useful - otherwise, why use --count?) Also ensured that the
719        combination -clh just lists non-zero counts, with no names.
720    
721    4.  The long form of the pcregrep -F option was incorrectly implemented as
722        --fixed_strings instead of --fixed-strings. This is an incompatible change,
723        but it seems right to fix it, and I didn't think it was worth preserving
724        the old behaviour.
725    
726    5.  The command line items --regex=pattern and --regexp=pattern were not
727        recognized by pcregrep, which required --regex pattern or --regexp pattern
728        (with a space rather than an '='). The man page documented the '=' forms,
729        which are compatible with GNU grep; these now work.
730    
731    6.  No libpcreposix.pc file was created for pkg-config; there was just
732        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
733    
734    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
735        when UCP support is not needed, by modifying the Python script that
736        generates it from Unicode data files. This should not matter if the module
737        is correctly used as a library, but I received one complaint about 50K of
738        unwanted data. My guess is that the person linked everything into his
739        program rather than using a library. Anyway, it does no harm.
740    
741    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
742        was a minimum greater than 1 for a wide character in a possessive
743        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
744        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
745        character. Chaos in the form of incorrect output or a compiling loop could
746        result.
747    
748    9.  The restrictions on what a pattern can contain when partial matching is
749        requested for pcre_exec() have been removed. All patterns can now be
750        partially matched by this function. In addition, if there are at least two
751        slots in the offset vector, the offset of the earliest inspected character
752        for the match and the offset of the end of the subject are set in them when
753        PCRE_ERROR_PARTIAL is returned.
754    
755    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
756        synonymous with PCRE_PARTIAL, for backwards compatibility, and
757        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
758        and may be more useful for multi-segment matching.
759    
760    11. Partial matching with pcre_exec() is now more intuitive. A partial match
761        used to be given if ever the end of the subject was reached; now it is
762        given only if matching could not proceed because another character was
763        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
764        string "Z", which now yields "no match" instead of "partial match". In the
765        case of pcre_dfa_exec(), "no match" is given if every matching path for the
766        final character ended with (*FAIL).
767    
768    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
769        if the pattern had a "must contain" character that was already found in the
770        earlier partial match, unless partial matching was again requested. For
771        example, with the pattern /dog.(body)?/, the "must contain" character is
772        "g". If the first part-match was for the string "dog", restarting with
773        "sbody" failed. This bug has been fixed.
774    
775    13. The string returned by pcre_dfa_exec() after a partial match has been
776        changed so that it starts at the first inspected character rather than the
777        first character of the match. This makes a difference only if the pattern
778        starts with a lookbehind assertion or \b or \B (\K is not supported by
779        pcre_dfa_exec()). It's an incompatible change, but it makes the two
780        matching functions compatible, and I think it's the right thing to do.
781    
782    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
783        so that the demonstration program is easily available in environments where
784        PCRE has not been installed from source.
785    
786    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
787        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
788        library.
789    
790    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
791        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
792        is not the first non-POSIX option to be added. Clearly some people find
793        these options useful.
794    
795    17. If a caller to the POSIX matching function regexec() passes a non-zero
796        value for nmatch with a NULL value for pmatch, the value of
797        nmatch is forced to zero.
798    
799    18. RunGrepTest did not have a test for the availability of the -u option of
800        the diff command, as RunTest does. It now checks in the same way as
801        RunTest, and also checks for the -b option.
802    
803    19. If an odd number of negated classes containing just a single character
804        interposed, within parentheses, between a forward reference to a named
805        subpattern and the definition of the subpattern, compilation crashed with
806        an internal error, complaining that it could not find the referenced
807        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
808        [The bug was that it was starting one character too far in when skipping
809        over the character class, thus treating the ] as data rather than
810        terminating the class. This meant it could skip too much.]
811    
812    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
813        /g option in pcretest when the pattern contains \K, which makes it possible
814        to have an empty string match not at the start, even when the pattern is
815        anchored. Updated pcretest and pcredemo to use this option.
816    
817    21. If the maximum number of capturing subpatterns in a recursion was greater
818        than the maximum at the outer level, the higher number was returned, but
819        with unset values at the outer level. The correct (outer level) value is
820        now given.
821    
822    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
823        PCRE did not set those parentheses (unlike Perl). I have now found a way to
824        make it do so. The string so far is captured, making this feature
825        compatible with Perl.
826    
827    23. The tests have been re-organized, adding tests 11 and 12, to make it
828        possible to check the Perl 5.10 features against Perl 5.10.
829    
830    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
831        pattern matches a fixed length string. PCRE did not allow this; now it
832        does. Neither allows recursion.
833    
834    25. I finally figured out how to implement a request to provide the minimum
835        length of subject string that was needed in order to match a given pattern.
836        (It was back references and recursion that I had previously got hung up
837        on.) This code has now been added to pcre_study(); it finds a lower bound
838        to the length of subject needed. It is not necessarily the greatest lower
839        bound, but using it to avoid searching strings that are too short does give
840        some useful speed-ups. The value is available to calling programs via
841        pcre_fullinfo().
842    
843    26. While implementing 25, I discovered to my embarrassment that pcretest had
844        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
845        study optimizations had never been tested with that matching function.
846        Oops. What is worse, even when it was passed study data, there was a bug in
847        pcre_dfa_exec() that meant it never actually used it. Double oops. There
848        were also very few tests of studied patterns with pcre_dfa_exec().
849    
850    27. If (?| is used to create subpatterns with duplicate numbers, they are now
851        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
852        on the other side of the coin, they are no longer allowed to have different
853        names, because these cannot be distinguished in PCRE, and this has caused
854        confusion. (This is a difference from Perl.)
855    
856    28. When duplicate subpattern names are present (necessarily with different
857        numbers, as required by 27 above), and a test is made by name in a
858        conditional pattern, either for a subpattern having been matched, or for
859        recursion in such a pattern, all the associated numbered subpatterns are
860        tested, and the overall condition is true if the condition is true for any
861        one of them. This is the way Perl works, and is also more like the way
862        testing by number works.
863    
864    
865    Version 7.9 11-Apr-09
866    ---------------------
867    
868    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
869        (pcretest), all targets were linked against these libraries. This included
870        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
871        libraries. This caused unwanted dependencies to be created. This problem
872        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
873        pcretest is linked with readline.
874    
875    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
876        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
877        moved outside it again, because FALSE and TRUE are already defined in AIX,
878        but BOOL is not.
879    
880    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
881        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
882    
883    4.  The pcregrep documentation said spaces were inserted as well as colons (or
884        hyphens) following file names and line numbers when outputting matching
885        lines. This is not true; no spaces are inserted. I have also clarified the
886        wording for the --colour (or --color) option.
887    
888    5.  In pcregrep, when --colour was used with -o, the list of matching strings
889        was not coloured; this is different to GNU grep, so I have changed it to be
890        the same.
891    
892    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
893        each matching line was coloured. Now it goes on to look for further matches
894        of any of the test patterns, which is the same behaviour as GNU grep.
895    
896    7.  A pattern that could match an empty string could cause pcregrep to loop; it
897        doesn't make sense to accept an empty string match in pcregrep, so I have
898        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
899        seems to be how GNU grep behaves.
900    
901    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
902        start or after a newline", because the conditional assertion was not being
903        correctly handled. The rule now is that both the assertion and what follows
904        in the first alternative must satisfy the test.
905    
906    9.  If auto-callout was enabled in a pattern with a conditional group whose
907        condition was an assertion, PCRE could crash during matching, both with
908        pcre_exec() and pcre_dfa_exec().
909    
910    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
911        used for matching.
912    
913    11. Unicode property support in character classes was not working for
914        characters (bytes) greater than 127 when not in UTF-8 mode.
915    
916    12. Added the -M command line option to pcretest.
917    
918    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
919    
920    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
921    
922    16. Added comments and documentation about mis-use of no_arg in the C++
923        wrapper.
924    
925    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
926        from Martin Jerabek that uses macro names for all relevant character and
927        string constants.
928    
929    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
930        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
931        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
932        these, but not everybody uses configure.
933    
934    19. A conditional group that had only one branch was not being correctly
935        recognized as an item that could match an empty string. This meant that an
936        enclosing group might also not be so recognized, causing infinite looping
937        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
938        with the subject "ab", where knowledge that the repeated group can match
939        nothing is needed in order to break the loop.
940    
941    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
942        exec(), but without supplying a callout function, matching went wrong.
943    
944    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
945        leak if the size of the offset vector was greater than 30. When the vector
946        is smaller, the saved offsets during recursion go onto a local stack
947        vector, but for larger vectors malloc() is used. It was failing to free
948        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
949        error, in fact).
950    
951    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
952        heapframe that is used only when UTF-8 support is enabled. This caused no
953        problem, but was untidy.
954    
955    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
956        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
957        included within another project.
958    
959    24. Steven Van Ingelgem's patches to add more options to the CMake support,
960        slightly modified by me:
961    
962          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
963              not building pcregrep.
964    
965          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
966              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
967    
968    25. Forward references, both numeric and by name, in patterns that made use of
969        duplicate group numbers, could behave incorrectly or give incorrect errors,
970        because when scanning forward to find the reference group, PCRE was not
971        taking into account the duplicate group numbers. A pattern such as
972        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
973    
974    26. Changed a few more instances of "const unsigned char *" to USPTR, making
975        the feature of a custom pointer more persuasive (as requested by a user).
976    
977    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
978        pcretest.c, inside #ifndefs, because it seems they are sometimes already
979        pre-defined.
980    
981    28. Added support for (*UTF8) at the start of a pattern.
982    
983    29. Arrange for flags added by the "release type" setting in CMake to be shown
984        in the configuration summary.
985    
986    
987    Version 7.8 05-Sep-08
988    ---------------------
989    
990    1.  Replaced UCP searching code with optimized version as implemented for Ad
991        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
992        stage table and inline lookup instead of a function, giving speed ups of 2
993        to 5 times on some simple patterns that I tested. Permission was given to
994        distribute the MultiStage2.py script that generates the tables (it's not in
995        the tarball, but is in the Subversion repository).
996    
997    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
998        scripts.
999    
1000    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1001        a group with a zero qualifier. The result of the study could be incorrect,
1002        or the function might crash, depending on the pattern.
1003    
1004    4.  Caseless matching was not working for non-ASCII characters in back
1005        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1006        It now works when Unicode Property Support is available.
1007    
1008    5.  In pcretest, an escape such as \x{de} in the data was always generating
1009        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1010        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1011        truncation.
1012    
1013    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1014    
1015    7.  Added two (int) casts to pcregrep when printing the difference of two
1016        pointers, in case they are 64-bit values.
1017    
1018    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1019        test 2 if it fails.
1020    
1021    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1022        and a #define of that name to empty if it is not externally set. This is to
1023        allow users of MSVC to set it if necessary.
1024    
1025    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1026        the convenience functions in the pcre_get.c source file.
1027    
1028    11. An option change at the start of a pattern that had top-level alternatives
1029        could cause overwriting and/or a crash. This command provoked a crash in
1030        some environments:
1031    
1032          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1033    
1034        This potential security problem was recorded as CVE-2008-2371.
1035    
1036    12. For a pattern where the match had to start at the beginning or immediately
1037        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1038        pcre_dfa_exec() could read past the end of the passed subject if there was
1039        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1040        pcretest so that it places the subject at the end of its malloc-ed buffer.
1041    
1042    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1043        exec() might read past the end of the data buffer in UTF-8 mode.
1044    
1045    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1046        the data contained the byte 0x85 as part of a UTF-8 character within its
1047        first line. This applied both to normal and DFA matching.
1048    
1049    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1050        /^[^d]*?$/8 failed to match "abc".
1051    
1052    16. Added a missing copyright notice to pcrecpp_internal.h.
1053    
1054    17. Make it more clear in the documentation that values returned from
1055        pcre_exec() in ovector are byte offsets, not character counts.
1056    
1057    18. Tidied a few places to stop certain compilers from issuing warnings.
1058    
1059    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1060        supplied by Stefan Weber. I made a further small update for 7.8 because
1061        there is a change of source arrangements: the pcre_searchfuncs.c module is
1062        replaced by pcre_ucd.c.
1063    
1064    
1065    Version 7.7 07-May-08
1066    ---------------------
1067    
1068    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1069        a string to a long long, pretend we don't even have a long long." This is
1070        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1071    
1072    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1073        pre-7.6 versions, which defined a global no_arg variable instead of putting
1074        it in the RE class. (See also #8 below.)
1075    
1076    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1077        Lopes.
1078    
1079    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1080    
1081        (1) The include/exclude patterns were being applied to the whole pathnames
1082            of files, instead of just to the final components.
1083    
1084        (2) If there was more than one level of directory, the subdirectories were
1085            skipped unless they satisfied the include/exclude conditions. This is
1086            inconsistent with GNU grep (and could even be seen as contrary to the
1087            pcregrep specification - which I improved to make it absolutely clear).
1088            The action now is always to scan all levels of directory, and just
1089            apply the include/exclude patterns to regular files.
1090    
1091    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1092        --exclude_dir in the tests to avoid scanning .svn directories.
1093    
1094    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1095        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1096        doesn't support NULs in patterns.
1097    
1098    7.  Added some missing "const"s to declarations of static tables in
1099        pcre_compile.c and pcre_dfa_exec.c.
1100    
1101    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1102        caused by fix #2  above. (Subsequently also a second patch to fix the
1103        first patch. And a third patch - this was a messy problem.)
1104    
1105    9.  Applied Craig's patch to remove the use of push_back().
1106    
1107    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1108        matching function regexec().
1109    
1110    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1111        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1112        references. PCRE supports relative numbers with this syntax (I don't think
1113        Oniguruma does).
1114    
1115    12. Previously, a group with a zero repeat such as (...){0} was completely
1116        omitted from the compiled regex. However, this means that if the group
1117        was called as a subroutine from elsewhere in the pattern, things went wrong
1118        (an internal error was given). Such groups are now left in the compiled
1119        pattern, with a new opcode that causes them to be skipped at execution
1120        time.
1121    
1122    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1123        to the way PCRE behaves:
1124    
1125        (a) A lone ] character is dis-allowed (Perl treats it as data).
1126    
1127        (b) A back reference to an unmatched subpattern matches an empty string
1128            (Perl fails the current match path).
1129    
1130        (c) A data ] in a character class must be notated as \] because if the
1131            first data character in a class is ], it defines an empty class. (In
1132            Perl it is not possible to have an empty class.) The empty class []
1133            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1134            The negative empty class [^] matches any one character, independently
1135            of the DOTALL setting.
1136    
1137    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1138        non-existent subpattern following a character class starting with ']' and
1139        containing () gave an internal compiling error instead of "reference to
1140        non-existent subpattern". Fortunately, when the pattern did exist, the
1141        compiled code was correct. (When scanning forwards to check for the
1142        existencd of the subpattern, it was treating the data ']' as terminating
1143        the class, so got the count wrong. When actually compiling, the reference
1144        was subsequently set up correctly.)
1145    
1146    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1147        it was being rejected as not supported by pcre_dfa_exec(), even though
1148        other assertions are supported. I have made pcre_dfa_exec() support
1149        (*FAIL).
1150    
1151    16. The implementation of 13c above involved the invention of a new opcode,
1152        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1153        cannot be changed at match time, I realized I could make a small
1154        improvement to matching performance by compiling OP_ALLANY instead of
1155        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1156        on the OP_ANY path.
1157    
1158    17. Compiling pcretest on Windows with readline support failed without the
1159        following two fixes: (1) Make the unistd.h include conditional on
1160        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1161    
1162    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1163        ncurses library to be included for pcretest when ReadLine support is
1164        requested, but also to allow for it to be overridden. This patch came from
1165        Daniel Bergström.
1166    
1167    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1168        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1169        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1170        spotting this.
1171    
1172    
1173    Version 7.6 28-Jan-08
1174    ---------------------
1175    
1176    1.  A character class containing a very large number of characters with
1177        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1178        overflow.
1179    
1180    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1181        HAVE_LONG_LONG is not defined.
1182    
1183    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1184        bring them up to date and include new features. This patch includes:
1185    
1186        - Fixed PH's badly added libz and libbz2 support.
1187        - Fixed a problem with static linking.
1188        - Added pcredemo. [But later removed - see 7 below.]
1189        - Fixed dftables problem and added an option.
1190        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1191            HAVE_LONG_LONG.
1192        - Added readline support for pcretest.
1193        - Added an listing of the option settings after cmake has run.
1194    
1195    4.  A user submitted a patch to Makefile that makes it easy to create
1196        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1197        Makefile.am that cause it to include this special target, without
1198        affecting anything else. Note that the same mingw target plus all
1199        the other distribution libraries and programs are now supported
1200        when configuring with CMake (see 6 below) instead of with
1201        Configure/Make.
1202    
1203    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1204        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1205        exported in the Windows port". It has not yet been confirmed that the patch
1206        solves the problem, but it does no harm.
1207    
1208    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1209        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1210        with CMake, and also correct the comment about stack recursion.
1211    
1212    7.  Remove the automatic building of pcredemo from the ./configure system and
1213        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1214        of a program that users should build themselves after PCRE is installed, so
1215        building it automatically is not really right. What is more, it gave
1216        trouble in some build environments.
1217    
1218    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1219    
1220    
1221    Version 7.5 10-Jan-08
1222    ---------------------
1223    
1224    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1225        values in parens when parsing an RE using the C++ wrapper."
1226    
1227    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1228        Characters greater than 255 were excluded from the class instead of being
1229        included.
1230    
1231    3.  The same bug as (2) above applied to negated POSIX classes such as
1232        [:^space:].
1233    
1234    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1235        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1236        I have changed it.
1237    
1238    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1239        first named subpattern) and a construct such as (?&a) would reference the
1240        first named subpattern whose name started with "a" (in other words, the
1241        length check was missing). Both these problems are fixed. "Subpattern name
1242        expected" is now given for (?&) (a zero-length name), and this patch also
1243        makes it give the same error for \k'' (previously it complained that that
1244        was a reference to a non-existent subpattern).
1245    
1246    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1247        this is right because (?- can be followed by option settings as well as by
1248        digits. I have, however, made the messages clearer.
1249    
1250    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1251        than the number used in the conditional) now cause a compile-time error.
1252        This is actually not compatible with Perl, which accepts such patterns, but
1253        treats the conditional as always being FALSE (as PCRE used to), but it
1254        seems to me that giving a diagnostic is better.
1255    
1256    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1257        and messages.
1258    
1259    9.  Fix two occurrences of "backslash" in comments that should have been
1260        "backspace".
1261    
1262    10. Remove two redundant lines of code that can never be obeyed (their function
1263        was moved elsewhere).
1264    
1265    11. The program that makes PCRE's Unicode character property table had a bug
1266        which caused it to generate incorrect table entries for sequences of
1267        characters that have the same character type, but are in different scripts.
1268        It amalgamated them into a single range, with the script of the first of
1269        them. In other words, some characters were in the wrong script. There were
1270        thirteen such cases, affecting characters in the following ranges:
1271    
1272          U+002b0 - U+002c1
1273          U+0060c - U+0060d
1274          U+0061e - U+00612
1275          U+0064b - U+0065e
1276          U+0074d - U+0076d
1277          U+01800 - U+01805
1278          U+01d00 - U+01d77
1279          U+01d9b - U+01dbf
1280          U+0200b - U+0200f
1281          U+030fc - U+030fe
1282          U+03260 - U+0327f
1283          U+0fb46 - U+0fbb1
1284          U+10450 - U+1049d
1285    
1286    12. The -o option (show only the matching part of a line) for pcregrep was not
1287        compatible with GNU grep in that, if there was more than one match in a
1288        line, it showed only the first of them. It now behaves in the same way as
1289        GNU grep.
1290    
1291    13. If the -o and -v options were combined for pcregrep, it printed a blank
1292        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1293        does the same. The return code can be used to tell if there were any
1294        non-matching lines.
1295    
1296    14. Added --file-offsets and --line-offsets to pcregrep.
1297    
1298    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1299        infinitely looping recursion. The bug was that positive lookaheads were not
1300        being skipped when checking for a possible empty match (negative lookaheads
1301        and both kinds of lookbehind were skipped).
1302    
1303    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1304        inclusion of <windows.h> to before rather than after the definition of
1305        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1306    
1307    17. Specifying a possessive quantifier with a specific limit for a Unicode
1308        character property caused pcre_compile() to compile bad code, which led at
1309        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1310        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1311        caused the error; without that there was no problem.
1312    
1313    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1314    
1315    19. Added --enable-pcretest-libreadline.
1316    
1317    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1318        RE::GlobalReplace(). As a result, the number of replacements returned was
1319        double what it should be. I removed one of the increments, but Craig sent a
1320        later patch that removed the other one (the right fix) and added unit tests
1321        that check the return values (which was not done before).
1322    
1323    21. Several CMake things:
1324    
1325        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1326            the names libpcre and libpcreposix, not just pcre and pcreposix.
1327    
1328        (2) The above change means that pcretest and pcregrep are now correctly
1329            linked with the newly-built libraries, not previously installed ones.
1330    
1331        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1332    
1333    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1334        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1335        UTF-8 newline character). The key issue is that the pattern starts .*;
1336        this means that the match must be either at the beginning, or after a
1337        newline. The bug was in the code for advancing after a failed match and
1338        checking that the new position followed a newline. It was not taking
1339        account of UTF-8 characters correctly.
1340    
1341    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1342        character classes. PCRE was not treating the sequence [:...:] as a
1343        character class unless the ... were all letters. Perl, however, seems to
1344        allow any characters between [: and :], though of course it rejects as
1345        unknown any "names" that contain non-letters, because all the known class
1346        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1347        for example, whereas PCRE did not - it did not recognize a POSIX character
1348        class. This seemed a bit dangerous, so the code has been changed to be
1349        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1350        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1351        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1352        Perl does, and where it didn't before.
1353    
1354    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1355        Windows environments %n is disabled by default.
1356    
1357    
1358    Version 7.4 21-Sep-07
1359    ---------------------
1360    
1361    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1362        means that a class such as [\s] counted as "explicit reference to CR or
1363        LF". That isn't really right - the whole point of the change was to try to
1364        help when there was an actual mention of one of the two characters. So now
1365        the change happens only if \r or \n (or a literal CR or LF) character is
1366        encountered.
1367    
1368    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1369        of both had grown to the point where there were only 3 bits left.
1370        Fortunately, there was spare space in the data structure, and so I have
1371        moved the internal flags into a new 16-bit field to free up more option
1372        bits.
1373    
1374    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1375        but did not set the internal JCHANGED flag - either of these is enough to
1376        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1377        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1378        start sets both bits.
1379    
1380    4.  Added options (at build time, compile time, exec time) to change \R from
1381        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1382    
1383    5.  doc/pcresyntax.html was missing from the distribution.
1384    
1385    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1386        compatibility, even though it is no longer used.
1387    
1388    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1389        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1390        windows.h file is present (where different names are used). [This was
1391        reversed later after testing - see 16 below.]
1392    
1393    8.  Changed all #include <config.h> to #include "config.h". There were also
1394        some further <pcre.h> cases that I changed to "pcre.h".
1395    
1396    9.  When pcregrep was used with the --colour option, it missed the line ending
1397        sequence off the lines that it output.
1398    
1399    10. It was pointed out to me that arrays of string pointers cause lots of
1400        relocations when a shared library is dynamically loaded. A technique of
1401        using a single long string with a table of offsets can drastically reduce
1402        these. I have refactored PCRE in four places to do this. The result is
1403        dramatic:
1404    
1405          Originally:                          290
1406          After changing UCP table:            187
1407          After changing error message table:   43
1408          After changing table of "verbs"       36
1409          After changing table of Posix names   22
1410    
1411        Thanks to the folks working on Gregex for glib for this insight.
1412    
1413    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1414        unicode-properties was also set.
1415    
1416    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1417    
1418    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1419        checked only for CRLF.
1420    
1421    14. Added casts to pcretest.c to avoid compiler warnings.
1422    
1423    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1424    
1425    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1426        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1427        entirely. This removes changes made in 7 above.
1428    
1429    17. The CMake files have been updated, and there is now more information about
1430        building with CMake in the NON-UNIX-USE document.
1431    
1432    
1433    Version 7.3 28-Aug-07
1434    ---------------------
1435    
1436     1. In the rejigging of the build system that eventually resulted in 7.1, the
1437        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1438        brackets there is not right, since it causes compilers to look for an
1439        installed pcre.h, not the version that is in the source that is being
1440        compiled (which of course may be different). I have changed it back to:
1441    
1442          #include "pcre.h"
1443    
1444        I have a vague recollection that the change was concerned with compiling in
1445        different directories, but in the new build system, that is taken care of
1446        by the VPATH setting the Makefile.
1447    
1448     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1449        when the subject happened to end in the byte 0x85 (e.g. if the last
1450        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1451        characters but of course it shouldn't be taken as a newline when it is part
1452        of another character. The bug was that, for an unlimited repeat of . in
1453        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1454        characters when looking for a newline.
1455    
1456     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1457    
1458     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1459        in debug output.
1460    
1461     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1462        long printing in the pcrecpp unittest when running under MinGW.
1463    
1464     6. ESC_K was left out of the EBCDIC table.
1465    
1466     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1467        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1468        limit also applies to "virtual nesting" when a pattern is recursive, and in
1469        this case 1000 isn't so big. I have been able to remove this limit at the
1470        expense of backing off one optimization in certain circumstances. Normally,
1471        when pcre_exec() would call its internal match() function recursively and
1472        immediately return the result unconditionally, it uses a "tail recursion"
1473        feature to save stack. However, when a subpattern that can match an empty
1474        string has an unlimited repetition quantifier, it no longer makes this
1475        optimization. That gives it a stack frame in which to save the data for
1476        checking that an empty string has been matched. Previously this was taken
1477        from the 1000-entry workspace that had been reserved. So now there is no
1478        explicit limit, but more stack is used.
1479    
1480     8. Applied Daniel's patches to solve problems with the import/export magic
1481        syntax that is required for Windows, and which was going wrong for the
1482        pcreposix and pcrecpp parts of the library. These were overlooked when this
1483        problem was solved for the main library.
1484    
1485     9. There were some crude static tests to avoid integer overflow when computing
1486        the size of patterns that contain repeated groups with explicit upper
1487        limits. As the maximum quantifier is 65535, the maximum group length was
1488        set at 30,000 so that the product of these two numbers did not overflow a
1489        32-bit integer. However, it turns out that people want to use groups that
1490        are longer than 30,000 bytes (though not repeat them that many times).
1491        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1492        made it possible to implement the integer overflow checks in a much more
1493        dynamic way, which I have now done. The artificial limitation on group
1494        length has been removed - we now have only the limit on the total length of
1495        the compiled pattern, which depends on the LINK_SIZE setting.
1496    
1497    10. Fixed a bug in the documentation for get/copy named substring when
1498        duplicate names are permitted. If none of the named substrings are set, the
1499        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1500        empty string.
1501    
1502    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1503        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1504        because the ] is interpreted as the first data character and the
1505        terminating ] is not found. PCRE has been made compatible with Perl in this
1506        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1507        cause memory overwriting.
1508    
1509    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1510        string has been matched (to stop an infinite loop). It was not recognizing
1511        a conditional subpattern that could match an empty string if that
1512        subpattern was within another subpattern. For example, it looped when
1513        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1514        condition was not nested. This bug has been fixed.
1515    
1516    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1517        past the start of the subject in the presence of bytes with the top bit
1518        set, for example "\x8aBCD".
1519    
1520    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1521        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1522    
1523    14. Optimized (?!) to (*FAIL).
1524    
1525    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1526        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1527        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1528        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1529        does: it's just the validity check that is more restrictive.
1530    
1531    16. Inserted checks for integer overflows during escape sequence (backslash)
1532        processing, and also fixed erroneous offset values for syntax errors during
1533        backslash processing.
1534    
1535    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1536        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1537    
1538    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1539        caused an overrun.
1540    
1541    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1542        something other than just ASCII characters) inside a group that had an
1543        unlimited repeat caused a loop at compile time (while checking to see
1544        whether the group could match an empty string).
1545    
1546    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1547        [\P{Any}] did so. (Error in the code for printing property names.)
1548    
1549    21. An orphan \E inside a character class could cause a crash.
1550    
1551    22. A repeated capturing bracket such as (A)? could cause a wild memory
1552        reference during compilation.
1553    
1554    23. There are several functions in pcre_compile() that scan along a compiled
1555        expression for various reasons (e.g. to see if it's fixed length for look
1556        behind). There were bugs in these functions when a repeated \p or \P was
1557        present in the pattern. These operators have additional parameters compared
1558        with \d, etc, and these were not being taken into account when moving along
1559        the compiled data. Specifically:
1560    
1561        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1562            length.
1563    
1564        (b) An item such as \pL+ within a repeated group could cause crashes or
1565            loops.
1566    
1567        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1568            "reference to non-existent subpattern" error.
1569    
1570        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1571    
1572    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1573        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1574    
1575    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1576    
1577    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1578        character were causing crashes (broken optimization).
1579    
1580    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1581        \p or \P) caused a compile-time loop.
1582    
1583    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1584        break. For example, the unstudied pattern [\r\n]A does not match the string
1585        "\r\nA" because change 7.0/46 below moves the current point on by two
1586        characters after failing to match at the start. However, the pattern \nA
1587        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1588        the same is true. There doesn't seem any very clean way out of this, but
1589        what I have chosen to do makes the common cases work: PCRE now takes note
1590        of whether there can be an explicit match for \r or \n anywhere in the
1591        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1592        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1593        pattern has explicit CR or LF references.
1594    
1595    29. Added (*CR) etc for changing newline setting at start of pattern.
1596    
1597    
1598    Version 7.2 19-Jun-07
1599    ---------------------
1600    
1601     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1602        which is apparently normally available under Windows.
1603    
1604     2. Re-jig the pcregrep tests with different newline settings in an attempt
1605        to make them independent of the local environment's newline setting.
1606    
1607     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1608    
1609     4. Some of the "internals" tests were previously cut out when the link size
1610        was not 2, because the output contained actual offsets. The recent new
1611        "Z" feature of pcretest means that these can be cut out, making the tests
1612        usable with all link sizes.
1613    
1614     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1615        stack recursion. This gives a massive performance boost under BSD, but just
1616        a small improvement under Linux. However, it saves one field in the frame
1617        in all cases.
1618    
1619     6. Added more features from the forthcoming Perl 5.10:
1620    
1621        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1622            recursion call. It refers to the nth most recently opened parentheses.
1623    
1624        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1625            to be opened parentheses.
1626    
1627        (c) Conditions that refer to capturing parentheses can be specified
1628            relatively, for example, (?(-2)... or (?(+3)...
1629    
1630        (d) \K resets the start of the current match so that everything before
1631            is not part of it.
1632    
1633        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1634    
1635        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1636            reference syntax.
1637    
1638        (g) (?| introduces a group in which the numbering of parentheses in each
1639            alternative starts with the same number.
1640    
1641        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1642    
1643     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1644        PCRE_INFO_JCHANGED.
1645    
1646     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1647        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1648        for detecting groups that can match an empty string.
1649    
1650     9. A pattern with a very large number of alternatives (more than several
1651        hundred) was running out of internal workspace during the pre-compile
1652        phase, where pcre_compile() figures out how much memory will be needed. A
1653        bit of new cunning has reduced the workspace needed for groups with
1654        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1655        workspace instead of running out of the 4096 that are available.
1656    
1657    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1658    
1659    11. Applied patch from Google to remove an optimization that didn't quite work.
1660        The report of the bug said:
1661    
1662          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1663          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1664          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1665    
1666    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1667        it matched the wrong number of bytes.
1668    
1669    
1670    Version 7.1 24-Apr-07
1671    ---------------------
1672    
1673     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1674        that is more "standard", making use of automake and other Autotools. There
1675        is some re-arrangement of the files and adjustment of comments consequent
1676        on this.
1677    
1678     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1679        for recursive directory scanning broke on some systems because the files
1680        are not scanned in any specific order and on different systems the order
1681        was different. A call to "sort" has been inserted into RunGrepTest for the
1682        approprate test as a short-term fix. In the longer term there may be an
1683        alternative.
1684    
1685     3. I had an email from Eric Raymond about problems translating some of PCRE's
1686        man pages to HTML (despite the fact that I distribute HTML pages, some
1687        people do their own conversions for various reasons). The problems
1688        concerned the use of low-level troff macros .br and .in. I have therefore
1689        removed all such uses from the man pages (some were redundant, some could
1690        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1691        HTML has been updated to handle .nf/.fi and to complain if it encounters
1692        .br or .in.
1693    
1694     4. Updated comments in configure.ac that get placed in config.h.in and also
1695        arranged for config.h to be included in the distribution, with the name
1696        config.h.generic, for the benefit of those who have to compile without
1697        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1698    
1699     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1700        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1701        makevp.bat for the current PCRE, using the additional files
1702        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1703    
1704     6. A Windows user reported a minor discrepancy with test 2, which turned out
1705        to be caused by a trailing space on an input line that had got lost in his
1706        copy. The trailing space was an accident, so I've just removed it.
1707    
1708     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1709        that is needed.
1710    
1711     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1712        as "const" (a) because they are and (b) because it helps the PHP
1713        maintainers who have recently made a script to detect big data structures
1714        in the php code that should be moved to the .rodata section. I remembered
1715        to update Builducptable as well, so it won't revert if ucptable.h is ever
1716        re-created.
1717    
1718     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1719        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1720        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1721        support is not required. This saves 1.5-2K of code, which is important in
1722        some applications.
1723    
1724        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1725        so as not to refer to the tables, even though these functions will never be
1726        called when UTF-8 support is disabled. Otherwise there are problems with a
1727        shared library.
1728    
1729    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1730    
1731        (a) It was defining its arguments as char * instead of void *.
1732    
1733        (b) It was assuming that all moves were upwards in memory; this was true
1734            a long time ago when I wrote it, but is no longer the case.
1735    
1736        The emulated memove() is provided for those environments that have neither
1737        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1738        is clearly not the case, as these two bugs were recently reported.
1739    
1740    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1741        and Detrail to create the HTML documentation, the .txt form of the man
1742        pages, and it removes trailing spaces from listed files. It also creates
1743        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1744        case, it wraps all the #defines with #ifndefs. This script should be run
1745        before "make dist".
1746    
1747    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1748        with Unicode property support.
1749    
1750        (a) For a maximizing quantifier, if the two different cases of the
1751            character were of different lengths in their UTF-8 codings (there are
1752            some cases like this - I found 11), and the matching function had to
1753            back up over a mixture of the two cases, it incorrectly assumed they
1754            were both the same length.
1755    
1756        (b) When PCRE was configured to use the heap rather than the stack for
1757            recursion during matching, it was not correctly preserving the data for
1758            the other case of a UTF-8 character when checking ahead for a match
1759            while processing a minimizing repeat. If the check also involved
1760            matching a wide character, but failed, corruption could cause an
1761            erroneous result when trying to check for a repeat of the original
1762            character.
1763    
1764    13. Some tidying changes to the testing mechanism:
1765    
1766        (a) The RunTest script now detects the internal link size and whether there
1767            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1768            values substituted by "configure". (The RunGrepTest script already did
1769            this for UTF-8.) The configure.ac script no longer substitutes the
1770            relevant variables.
1771    
1772        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1773            with length and offset values. This means that the output is different
1774            for different internal link sizes. Test 2 is skipped for link sizes
1775            other than 2 because of this, bypassing the problem. Unfortunately,
1776            there was also a test in test 3 (the locale tests) that used /B and
1777            failed for link sizes other than 2. Rather than cut the whole test out,
1778            I have added a new /Z option to pcretest that replaces the length and
1779            offset values with spaces. This is now used to make test 3 independent
1780            of link size. (Test 2 will be tidied up later.)
1781    
1782    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1783        segmentation fault instead of returning the appropriate error message.
1784    
1785    15. In multiline mode when the newline sequence was set to "any", the pattern
1786        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1787        This doesn't seem right; it now treats the CRLF combination as the line
1788        ending, and so does not match in that case. It's only a pattern such as ^$
1789        that would hit this one: something like ^ABC$ would have failed after \r
1790        and then tried again after \r\n.
1791    
1792    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1793        in an attempt to make files that differ only in their line terminators
1794        compare equal. This works on Linux.
1795    
1796    17. Under certain error circumstances pcregrep might try to free random memory
1797        as it exited. This is now fixed, thanks to valgrind.
1798    
1799    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1800        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1801        was because its rules for how to advance for /g after matching an empty
1802        string at the end of a line did not allow for this case. They now check for
1803        it specially.
1804    
1805    20. pcretest is supposed to handle patterns and data of any length, by
1806        extending its buffers when necessary. It was getting this wrong when the
1807        buffer for a data line had to be extended.
1808    
1809    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1810        CRLF as a newline sequence.
1811    
1812    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1813        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1814        I have nevertheless tidied it up.
1815    
1816    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1817    
1818    24. Added a man page for pcre-config.
1819    
1820    
1821  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1822  ---------------------  ---------------------
1823    

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