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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.5 23-Dec-07  Version 8.20 10-Oct-2011
5    ------------------------
6    
7    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
8        a POSIX class. After further experiments with Perl, which convinced me that
9        Perl has bugs and confusions, a closing square bracket is no longer allowed
10        in a POSIX name. This bug also affected patterns with classes that started
11        with full stops.
12    
13    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
14        captured substring, but while checking the failing first alternative,
15        substring 1 is temporarily captured. If the output vector supplied to
16        pcre_exec() was not big enough for this capture, the yield of the function
17        was still zero ("insufficient space for captured substrings"). This cannot
18        be totally fixed without adding another stack variable, which seems a lot
19        of expense for a edge case. However, I have improved the situation in cases
20        such as /(a)(b)x|abc/ matched against "abc", where the return code
21        indicates that fewer than the maximum number of slots in the ovector have
22        been set.
23    
24    3.  Related to (2) above: when there are more back references in a pattern than
25        slots in the output vector, pcre_exec() uses temporary memory during
26        matching, and copies in the captures as far as possible afterwards. It was
27        using the entire output vector, but this conflicts with the specification
28        that only 2/3 is used for passing back captured substrings. Now it uses
29        only the first 2/3, for compatibility. This is, of course, another edge
30        case.
31    
32    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
33        main code base, and can be used by building with --enable-jit. When this is
34        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
35        runtime --no-jit option is given.
36    
37    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
38        ovector, the return from the function was zero, implying that there were
39        other matches that did not fit. The correct "exactly full" value is now
40        returned.
41    
42    6.  If a subpattern that was called recursively or as a subroutine contained
43        (*PRUNE) or any other control that caused it to give a non-standard return,
44        invalid errors such as "Error -26 (nested recursion at the same subject
45        position)" or even infinite loops could occur.
46    
47    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
48        computing the minimum length on reaching *ACCEPT, and so ended up with the
49        wrong value of 1 rather than 0. Further investigation indicates that
50        computing a minimum subject length in the presence of *ACCEPT is difficult
51        (think back references, subroutine calls), and so I have changed the code
52        so that no minimum is registered for a pattern that contains *ACCEPT.
53    
54    8.  If (*THEN) was present in the first (true) branch of a conditional group,
55        it was not handled as intended. [But see 16 below.]
56    
57    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
58        Sheri Pierce.
59    
60    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
61        the first byte in a match must be "a".
62    
63    11. Change 17 for 8.13 increased the recursion depth for patterns like
64        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
65        pattern contains any instances of (*THEN). If it does not, the old
66        optimizations are restored. It would be nice to do this on a per-group
67        basis, but at the moment that is not feasible.
68    
69    12. In some environments, the output of pcretest -C is CRLF terminated. This
70        broke RunTest's code that checks for the link size. A single white space
71        after the value is now allowed for.
72    
73    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
74        For "fr", it uses the Windows-specific input and output files.
75    
76    14. If (*THEN) appeared in a group that was called recursively or as a
77        subroutine, it did not work as intended. [But see next item.]
78    
79    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
80        pattern fragments (but not containing any | characters). If A and B are
81        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
82        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
83        D. In other words, Perl considers parentheses that do not contain any |
84        characters to be part of a surrounding alternative, whereas PCRE was
85        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
86        differently. PCRE now behaves in the same way as Perl, except in the case
87        of subroutine/recursion calls such as (?1) which have in any case always
88        been different (but PCRE had them first :-).
89    
90    16. Related to 15 above: Perl does not treat the | in a conditional group as
91        creating alternatives. Such a group is treated in the same way as an
92        ordinary group without any | characters when processing (*THEN). PCRE has
93        been changed to match Perl's behaviour.
94    
95    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
96        RunGrepTest script failed.
97    
98    18. Change 22 for version 13 caused atomic groups to use more stack. This is
99        inevitable for groups that contain captures, but it can lead to a lot of
100        stack use in large patterns. The old behaviour has been restored for atomic
101        groups that do not contain any capturing parentheses.
102    
103    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
104        suppress the check for a minimum subject length at run time. (If it was
105        given to pcre_exec() or pcre_dfa_exec() it did work.)
106    
107    
108    Version 8.13 16-Aug-2011
109    ------------------------
110    
111    1.  The Unicode data tables have been updated to Unicode 6.0.0.
112    
113    2.  Two minor typos in pcre_internal.h have been fixed.
114    
115    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
116        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
117        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
118    
119    4.  There were a number of related bugs in the code for matching backrefences
120        caselessly in UTF-8 mode when codes for the characters concerned were
121        different numbers of bytes. For example, U+023A and U+2C65 are an upper
122        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
123        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
124        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
125        2-byte code at the end of the subject (it thought there wasn't enough data
126        left).
127    
128    5.  Comprehensive information about what went wrong is now returned by
129        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
130        as the output vector has at least 2 elements. The offset of the start of
131        the failing character and a reason code are placed in the vector.
132    
133    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
134        now returned is for the first byte of the failing character, instead of the
135        last byte inspected. This is an incompatible change, but I hope it is small
136        enough not to be a problem. It makes the returned offset consistent with
137        pcre_exec() and pcre_dfa_exec().
138    
139    7.  pcretest now gives a text phrase as well as the error number when
140        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
141        failure, the offset and reason code are output.
142    
143    8.  When \R was used with a maximizing quantifier it failed to skip backwards
144        over a \r\n pair if the subsequent match failed. Instead, it just skipped
145        back over a single character (\n). This seems wrong (because it treated the
146        two characters as a single entity when going forwards), conflicts with the
147        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
148        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
149        has been changed.
150    
151    9.  Some internal refactoring has changed the processing so that the handling
152        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
153        time (the PCRE_DOTALL option was changed this way some time ago: version
154        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
155        which was always a bit of a fudge. It also means that there is one less
156        argument for the match() function, which reduces its stack requirements
157        slightly. This change also fixes an incompatibility with Perl: the pattern
158        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
159    
160    10. More internal refactoring has drastically reduced the number of recursive
161        calls to match() for possessively repeated groups such as (abc)++ when
162        using pcre_exec().
163    
164    11. While implementing 10, a number of bugs in the handling of groups were
165        discovered and fixed:
166    
167        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
168        (a|)*(?1) gave a compile-time internal error.
169        ((a|)+)+  did not notice that the outer group could match an empty string.
170        (^a|^)+   was not marked as anchored.
171        (.*a|.*)+ was not marked as matching at start or after a newline.
172    
173    12. Yet more internal refactoring has removed another argument from the match()
174        function. Special calls to this function are now indicated by setting a
175        value in a variable in the "match data" data block.
176    
177    13. Be more explicit in pcre_study() instead of relying on "default" for
178        opcodes that mean there is no starting character; this means that when new
179        ones are added and accidentally left out of pcre_study(), testing should
180        pick them up.
181    
182    14. The -s option of pcretest has been documented for ages as being an old
183        synonym of -m (show memory usage). I have changed it to mean "force study
184        for every regex", that is, assume /S for every regex. This is similar to -i
185        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
186        using it. It makes it easier to run collections of tests with and without
187        study enabled, and thereby test pcre_study() more easily. All the standard
188        tests are now run with and without -s (but some patterns can be marked as
189        "never study" - see 20 below).
190    
191    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
192        restoration of the capturing data to the outer values was not happening
193        correctly.
194    
195    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
196        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
197        pattern had matched an empty string, and so incorrectly returned a no
198        match.
199    
200    17. There was optimizing code for the last branch of non-capturing parentheses,
201        and also for the obeyed branch of a conditional subexpression, which used
202        tail recursion to cut down on stack usage. Unfortunately, now that there is
203        the possibility of (*THEN) occurring in these branches, tail recursion is
204        no longer possible because the return has to be checked for (*THEN). These
205        two optimizations have therefore been removed. [But see 8.20/11 above.]
206    
207    18. If a pattern containing \R was studied, it was assumed that \R always
208        matched two bytes, thus causing the minimum subject length to be
209        incorrectly computed because \R can also match just one byte.
210    
211    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
212        was incorrectly computed.
213    
214    20. If /S is present twice on a test pattern in pcretest input, it now
215        *disables* studying, thereby overriding the use of -s on the command line
216        (see 14 above). This is necessary for one or two tests to keep the output
217        identical in both cases.
218    
219    21. When (*ACCEPT) was used in an assertion that matched an empty string and
220        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
221    
222    22. When an atomic group that contained a capturing parenthesis was
223        successfully matched, but the branch in which it appeared failed, the
224        capturing was not being forgotten if a higher numbered group was later
225        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
226        group 1 to "a", when in fact it should be unset. This applied to multi-
227        branched capturing and non-capturing groups, repeated or not, and also to
228        positive assertions (capturing in negative assertions does not happen
229        in PCRE) and also to nested atomic groups.
230    
231    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
232        subject after a captured substring, to make it easier to tell which of a
233        number of identical substrings has been captured.
234    
235    24. The way atomic groups are processed by pcre_exec() has been changed so that
236        if they are repeated, backtracking one repetition now resets captured
237        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
238        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
239        "aaa". Previously, it would have been "a". As part of this code
240        refactoring, the way recursive calls are handled has also been changed.
241    
242    25. If an assertion condition captured any substrings, they were not passed
243        back unless some other capturing happened later. For example, if
244        (?(?=(a))a) was matched against "a", no capturing was returned.
245    
246    26. When studying a pattern that contained subroutine calls or assertions,
247        the code for finding the minimum length of a possible match was handling
248        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
249        group 1 called group 2 while simultaneously a separate group 2 called group
250        1). A stack overflow occurred in this case. I have fixed this by limiting
251        the recursion depth to 10.
252    
253    27. Updated RunTest.bat in the distribution to the version supplied by Tom
254        Fortmann. This supports explicit test numbers on the command line, and has
255        argument validation and error reporting.
256    
257    28. An instance of \X with an unlimited repeat could fail if at any point the
258        first character it looked at was a mark character.
259    
260    29. Some minor code refactoring concerning Unicode properties and scripts
261        should reduce the stack requirement of match() slightly.
262    
263    30. Added the '=' option to pcretest to check the setting of unused capturing
264        slots at the end of the pattern, which are documented as being -1, but are
265        not included in the return count.
266    
267    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
268        compiled something random. Now it gives a compile-time error (as does
269        Perl).
270    
271    32. A *MARK encountered during the processing of a positive assertion is now
272        recorded and passed back (compatible with Perl).
273    
274    33. If --only-matching or --colour was set on a pcregrep call whose pattern
275        had alternative anchored branches, the search for a second match in a line
276        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
277        matched the line "0102" twice. The same bug affected patterns that started
278        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
279        twice.
280    
281    34. Previously, PCRE did not allow quantification of assertions. However, Perl
282        does, and because of capturing effects, quantifying parenthesized
283        assertions may at times be useful. Quantifiers are now allowed for
284        parenthesized assertions.
285    
286    35. A minor code tidy in pcre_compile() when checking options for \R usage.
287    
288    36. \g was being checked for fancy things in a character class, when it should
289        just be a literal "g".
290    
291    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
292        appearance of a nested POSIX class supersedes an apparent external class.
293        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
294        unescaped square brackets may also appear as part of class names. For
295        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
296        more like Perl. (But see 8.20/1 above.)
297    
298    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
299        was because it thought it was \N{name}, which is not supported).
300    
301    39. Add minix to OS list not supporting the -S option in pcretest.
302    
303    40. PCRE tries to detect cases of infinite recursion at compile time, but it
304        cannot analyze patterns in sufficient detail to catch mutual recursions
305        such as ((?1))((?2)). There is now a runtime test that gives an error if a
306        subgroup is called recursively as a subpattern for a second time at the
307        same position in the subject string. In previous releases this might have
308        been caught by the recursion limit, or it might have run out of stack.
309    
310    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
311        happen only once. PCRE was, however incorrectly giving a compile time error
312        "recursive call could loop indefinitely" because it cannot analyze the
313        pattern in sufficient detail. The compile time test no longer happens when
314        PCRE is compiling a conditional subpattern, but actual runaway loops are
315        now caught at runtime (see 40 above).
316    
317    42. It seems that Perl allows any characters other than a closing parenthesis
318        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
319        has been changed to be the same.
320    
321    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
322        as not to get warnings when autogen.sh is called. Also changed
323        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
324    
325    44. To help people who use pcregrep to scan files containing exceedingly long
326        lines, the following changes have been made:
327    
328        (a) The default value of the buffer size parameter has been increased from
329            8K to 20K. (The actual buffer used is three times this size.)
330    
331        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
332            PCRE is built.
333    
334        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
335            to be set at run time.
336    
337        (d) Numerical values in pcregrep options can be followed by K or M, for
338            example --buffer-size=50K.
339    
340        (e) If a line being scanned overflows pcregrep's buffer, an error is now
341            given and the return code is set to 2.
342    
343    45. Add a pointer to the latest mark to the callout data block.
344    
345    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
346        partial match of an empty string instead of no match. This was specific to
347        the use of ".".
348    
349    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
350        complete match instead of a partial match. This bug was dependent on both
351        the PCRE_UTF8 and PCRE_DOTALL options being set.
352    
353    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
354        starting byte set, because \b was not being ignored.
355    
356    
357    Version 8.12 15-Jan-2011
358    ------------------------
359    
360    1.  Fixed some typos in the markup of the man pages, and wrote a script that
361        checks for such things as part of the documentation building process.
362    
363    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
364        --match-limit and --recursion-limit options (added for 8.11). In
365        particular, this made one of the standard tests fail. (The integer value
366        went into the wrong half of a long int.)
367    
368    3.  If the --colour option was given to pcregrep with -v (invert match), it
369        did strange things, either producing crazy output, or crashing. It should,
370        of course, ignore a request for colour when reporting lines that do not
371        match.
372    
373    4.  Another pcregrep bug caused similar problems if --colour was specified with
374        -M (multiline) and the pattern match finished with a line ending.
375    
376    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
377        matched in multiline mode, the following line was shown as part of the
378        match. This seems wrong, so I have changed it.
379    
380    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
381        the check for further matches in the same line (so they could be coloured)
382        to overrun the end of the current line. If another match was found, it was
383        incorrectly shown (and then shown again when found in the next line).
384    
385    7.  If pcregrep was compiled under Windows, there was a reference to the
386        function pcregrep_exit() before it was defined. I am assuming this was
387        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
388        reported by a user. I've moved the definition above the reference.
389    
390    
391    Version 8.11 10-Dec-2010
392    ------------------------
393    
394    1.  (*THEN) was not working properly if there were untried alternatives prior
395        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
396        backtracked to try for "b" instead of moving to the next alternative branch
397        at the same level (in this case, to look for "c"). The Perl documentation
398        is clear that when (*THEN) is backtracked onto, it goes to the "next
399        alternative in the innermost enclosing group".
400    
401    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
402        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
403        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
404        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
405        (*THEN).
406    
407    3.  If \s appeared in a character class, it removed the VT character from
408        the class, even if it had been included by some previous item, for example
409        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
410        of \s, but is part of the POSIX "space" class.)
411    
412    4.  A partial match never returns an empty string (because you can always
413        match an empty string at the end of the subject); however the checking for
414        an empty string was starting at the "start of match" point. This has been
415        changed to the "earliest inspected character" point, because the returned
416        data for a partial match starts at this character. This means that, for
417        example, /(?<=abc)def/ gives a partial match for the subject "abc"
418        (previously it gave "no match").
419    
420    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
421        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
422        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
423        has an implication that the given string is incomplete (because a partial
424        match is preferred over a full match). For this reason, these items now
425        give a partial match in this situation. [Aside: previously, the one case
426        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
427        match rather than a full match, which was wrong by the old rules, but is
428        now correct.]
429    
430    6.  There was a bug in the handling of #-introduced comments, recognized when
431        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
432        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
433        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
434        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
435        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
436        places in pcre_compile().
437    
438    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
439        comments when looking ahead for named forward references to subpatterns,
440        the only newline sequence it recognized was NL. It now handles newlines
441        according to the set newline convention.
442    
443    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
444        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
445        cater for a lack of strerror(). These oversights have been fixed.
446    
447    9.  Added --match-limit and --recursion-limit to pcregrep.
448    
449    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
450    
451    11. When the -o option was used, pcregrep was setting a return code of 1, even
452        when matches were found, and --line-buffered was not being honoured.
453    
454    12. Added an optional parentheses number to the -o and --only-matching options
455        of pcregrep.
456    
457    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
458        can match an empty string. The code to do it in pcretest and pcredemo
459        needed fixing:
460    
461        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
462            only one byte after an empty string match just before CRLF (this case
463            just got forgotten; "any" and "anycrlf" were OK).
464    
465        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
466            mode when an empty string match preceded an ASCII character followed by
467            a non-ASCII character. (The code for advancing by one character rather
468            than one byte was nonsense.)
469    
470        (c) The pcredemo.c sample program did not have any code at all to handle
471            the cases when CRLF is a valid newline sequence.
472    
473    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
474        as a starting offset was within the subject string. There is now a new
475        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
476        negative or greater than the length of the string. In order to test this,
477        pcretest is extended to allow the setting of negative starting offsets.
478    
479    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
480        starting offset points to the beginning of a UTF-8 character was
481        unnecessarily clumsy. I tidied it up.
482    
483    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
484        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
485    
486    17. Nobody had reported that the --include_dir option, which was added in
487        release 7.7 should have been called --include-dir (hyphen, not underscore)
488        for compatibility with GNU grep. I have changed it to --include-dir, but
489        left --include_dir as an undocumented synonym, and the same for
490        --exclude-dir, though that is not available in GNU grep, at least as of
491        release 2.5.4.
492    
493    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
494        characters from a string of bytes) have been redefined so as not to use
495        loops, in order to improve performance in some environments. At the same
496        time, I abstracted some of the common code into auxiliary macros to save
497        repetition (this should not affect the compiled code).
498    
499    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
500        compile-time error is now given if \c is not followed by an ASCII
501        character, that is, a byte less than 128. (In EBCDIC mode, the code is
502        different, and any byte value is allowed.)
503    
504    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
505        START_OPTIMIZE option, which is now allowed at compile time - but just
506        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
507        to pcregrep and other applications that have no direct access to PCRE
508        options. The new /Y option in pcretest sets this option when calling
509        pcre_compile().
510    
511    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
512        back references. Groups containing recursive back references were forced to
513        be atomic by that change, but in the case of named groups, the amount of
514        memory required was incorrectly computed, leading to "Failed: internal
515        error: code overflow". This has been fixed.
516    
517    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
518        pcretest.c, to avoid build problems in some Borland environments.
519    
520    
521    Version 8.10 25-Jun-2010
522    ------------------------
523    
524    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
525        THEN.
526    
527    2.  (*ACCEPT) was not working when inside an atomic group.
528    
529    3.  Inside a character class, \B is treated as a literal by default, but
530        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
531        causes the error). The code is unchanged, but I tidied the documentation.
532    
533    4.  Inside a character class, PCRE always treated \R and \X as literals,
534        whereas Perl faults them if its -w option is set. I have changed PCRE so
535        that it faults them when PCRE_EXTRA is set.
536    
537    5.  Added support for \N, which always matches any character other than
538        newline. (It is the same as "." when PCRE_DOTALL is not set.)
539    
540    6.  When compiling pcregrep with newer versions of gcc which may have
541        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
542        declared with attribute warn_unused_result" were given. Just casting the
543        result to (void) does not stop the warnings; a more elaborate fudge is
544        needed. I've used a macro to implement this.
545    
546    7.  Minor change to pcretest.c to avoid a compiler warning.
547    
548    8.  Added four artifical Unicode properties to help with an option to make
549        \s etc use properties (see next item). The new properties are: Xan
550        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
551    
552    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
553        use Unicode properties. (*UCP) at the start of a pattern can be used to set
554        this option. Modified pcretest to add /W to test this facility. Added
555        REG_UCP to make it available via the POSIX interface.
556    
557    10. Added --line-buffered to pcregrep.
558    
559    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
560        studied, and the match started with a letter with a code point greater than
561        127 whose first byte was different to the first byte of the other case of
562        the letter, the other case of this starting letter was not recognized
563        (#976).
564    
565    12. If a pattern that was studied started with a repeated Unicode property
566        test, for example, \p{Nd}+, there was the theoretical possibility of
567        setting up an incorrect bitmap of starting bytes, but fortunately it could
568        not have actually happened in practice until change 8 above was made (it
569        added property types that matched character-matching opcodes).
570    
571    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
572        possible starting bytes for non-anchored patterns.
573    
574    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
575        \R, and also a number of cases that involve Unicode properties, both
576        explicit and implicit when PCRE_UCP is set.
577    
578    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
579        input, it could crash or give wrong results if characters with values
580        greater than 0xc0 were present in the subject string. (Detail: it assumed
581        UTF-8 input when processing these items.)
582    
583    16. Added a lot of (int) casts to avoid compiler warnings in systems where
584        size_t is 64-bit (#991).
585    
586    17. Added a check for running out of memory when PCRE is compiled with
587        --disable-stack-for-recursion (#990).
588    
589    18. If the last data line in a file for pcretest does not have a newline on
590        the end, a newline was missing in the output.
591    
592    19. The default pcre_chartables.c file recognizes only ASCII characters (values
593        less than 128) in its various bitmaps. However, there is a facility for
594        generating tables according to the current locale when PCRE is compiled. It
595        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
596        characters, are recognized by isspace() and therefore were getting set in
597        these tables, and indeed these tables seem to approximate to ISO 8859. This
598        caused a problem in UTF-8 mode when pcre_study() was used to create a list
599        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
600        which of course cannot start UTF-8 characters. I have changed the code so
601        that only real ASCII characters (less than 128) and the correct starting
602        bytes for UTF-8 encodings are set for characters greater than 127 when in
603        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
604        altogether.)
605    
606    20. Added the /T option to pcretest so as to be able to run tests with non-
607        standard character tables, thus making it possible to include the tests
608        used for 19 above in the standard set of tests.
609    
610    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
611        reference to a subpattern the other side of a comment that contains an
612        opening parenthesis caused either an internal compiling error, or a
613        reference to the wrong subpattern.
614    
615    
616    Version 8.02 19-Mar-2010
617    ------------------------
618    
619    1.  The Unicode data tables have been updated to Unicode 5.2.0.
620    
621    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
622        configured.
623    
624    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
625        original author of that file, following a query about its status.
626    
627    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
628        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
629    
630    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
631        quantifier applied to a forward-referencing subroutine call, could compile
632        incorrect code or give the error "internal error: previously-checked
633        referenced subpattern not found".
634    
635    6.  Both MS Visual Studio and Symbian OS have problems with initializing
636        variables to point to external functions. For these systems, therefore,
637        pcre_malloc etc. are now initialized to local functions that call the
638        relevant global functions.
639    
640    7.  There were two entries missing in the vectors called coptable and poptable
641        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
642        I've fixed the data, and added a kludgy way of testing at compile time that
643        the lengths are correct (equal to the number of opcodes).
644    
645    8.  Following on from 7, I added a similar kludge to check the length of the
646        eint vector in pcreposix.c.
647    
648    9.  Error texts for pcre_compile() are held as one long string to avoid too
649        much relocation at load time. To find a text, the string is searched,
650        counting zeros. There was no check for running off the end of the string,
651        which could happen if a new error number was added without updating the
652        string.
653    
654    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
655    
656    11. \K was not working if it appeared in an atomic group or in a group that
657        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
658        \K is "not well defined" if used in an assertion. PCRE now accepts it if
659        the assertion is positive, but not if it is negative.
660    
661    12. Change 11 fortuitously reduced the size of the stack frame used in the
662        "match()" function of pcre_exec.c by one pointer. Forthcoming
663        implementation of support for (*MARK) will need an extra pointer on the
664        stack; I have reserved it now, so that the stack frame size does not
665        decrease.
666    
667    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
668        item in branch that calls a recursion is a subroutine call - as in the
669        second branch in the above example - was incorrectly given the compile-
670        time error "recursive call could loop indefinitely" because pcre_compile()
671        was not correctly checking the subroutine for matching a non-empty string.
672    
673    14. The checks for overrunning compiling workspace could trigger after an
674        overrun had occurred. This is a "should never occur" error, but it can be
675        triggered by pathological patterns such as hundreds of nested parentheses.
676        The checks now trigger 100 bytes before the end of the workspace.
677    
678    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
679    
680    
681    Version 8.01 19-Jan-2010
682    ------------------------
683    
684    1.  If a pattern contained a conditional subpattern with only one branch (in
685        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
686        computed the wrong minimum data length (which is of course zero for such
687        subpatterns). This could cause incorrect "no match" results.
688    
689    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
690        the pattern is reset in the first branch, pcre_compile() failed with
691        "internal error: code overflow at offset...". This happened only when
692        the reset was to the original external option setting. (An optimization
693        abstracts leading options settings into an external setting, which was the
694        cause of this.)
695    
696    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
697        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
698        assertion pattern did not match (meaning that the assertion was true), it
699        was incorrectly treated as false if the SKIP had been reached during the
700        matching. This also applied to assertions used as conditions.
701    
702    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
703        assertion subpattern, including such a pattern used as a condition,
704        unpredictable results occurred, instead of the error return
705        PCRE_ERROR_DFA_UITEM.
706    
707    5.  The C++ GlobalReplace function was not working like Perl for the special
708        situation when an empty string is matched. It now does the fancy magic
709        stuff that is necessary.
710    
711    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
712        removed. (These were left over from very, very early versions of PCRE.)
713    
714    7.  Some cosmetic changes to the code to make life easier when compiling it
715        as part of something else:
716    
717        (a) Change DEBUG to PCRE_DEBUG.
718    
719        (b) In pcre_compile(), rename the member of the "branch_chain" structure
720            called "current" as "current_branch", to prevent a collision with the
721            Linux macro when compiled as a kernel module.
722    
723        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
724            prevent a collision with the Linux macro when compiled as a kernel
725            module.
726    
727    8.  In pcre_compile() there are some checks for integer overflows that used to
728        cast potentially large values to (double). This has been changed to that
729        when building, a check for int64_t is made, and if it is found, it is used
730        instead, thus avoiding the use of floating point arithmetic. (There is no
731        other use of FP in PCRE.) If int64_t is not found, the fallback is to
732        double.
733    
734    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
735        2005 (difference between two addresses compared to an unsigned value).
736    
737    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
738        custom one, because of the following reported problem in Windows:
739    
740          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
741              under Win32.
742          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
743              therefore missing the function definition.
744          - The compiler thus generates a "C" signature for the test function.
745          - The linker fails to find the "C" function.
746          - PCRE fails to configure if asked to do so against libbz2.
747    
748    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
749        messages were output:
750    
751          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
752          rerunning libtoolize, to keep the correct libtool macros in-tree.
753          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
754    
755        I have done both of these things.
756    
757    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
758        most of the time, it *can* run out if it is given a pattern that contains a
759        runaway infinite recursion. I updated the discussion in the pcrestack man
760        page.
761    
762    13. Now that we have gone to the x.xx style of version numbers, the minor
763        version may start with zero. Using 08 or 09 is a bad idea because users
764        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
765        interpreted as invalid octal numbers. I've updated the previous comment in
766        configure.ac, and also added a check that gives an error if 08 or 09 are
767        used.
768    
769    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
770        causing partial matching to fail when the end of the subject matched \W
771        in a UTF-8 pattern where \W was quantified with a minimum of 3.
772    
773    15. There were some discrepancies between the declarations in pcre_internal.h
774        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
775        their definitions. The declarations used "const uschar *" and the
776        definitions used USPTR. Even though USPTR is normally defined as "const
777        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
778        reported that: "This difference in casting confuses some C++ compilers, for
779        example, SunCC recognizes above declarations as different functions and
780        generates broken code for hbpcre." I have changed the declarations to use
781        USPTR.
782    
783    16. GNU libtool is named differently on some systems. The autogen.sh script now
784        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
785        (FreeBSD).
786    
787    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
788        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
789        comment: "Figure out how to create a longlong from a string: strtoll and
790        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
791        instance, but it only takes 2 args instead of 3!"
792    
793    18. A subtle bug concerned with back references has been fixed by a change of
794        specification, with a corresponding code fix. A pattern such as
795        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
796        refers, was giving matches when it shouldn't. For example, xa=xaaa would
797        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
798        same bug. Such groups have to be quantified to be useful, or contained
799        inside another quantified group. (If there's no repetition, the reference
800        can never match.) The problem arises because, having left the group and
801        moved on to the rest of the pattern, a later failure that backtracks into
802        the group uses the captured value from the final iteration of the group
803        rather than the correct earlier one. I have fixed this in PCRE by forcing
804        any group that contains a reference to itself to be an atomic group; that
805        is, there cannot be any backtracking into it once it has completed. This is
806        similar to recursive and subroutine calls.
807    
808    
809    Version 8.00 19-Oct-09
810    ----------------------
811    
812    1.  The table for translating pcre_compile() error codes into POSIX error codes
813        was out-of-date, and there was no check on the pcre_compile() error code
814        being within the table. This could lead to an OK return being given in
815        error.
816    
817    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
818        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
819        in a Windows environment.
820    
821    3.  The pcregrep --count option prints the count for each file even when it is
822        zero, as does GNU grep. However, pcregrep was also printing all files when
823        --files-with-matches was added. Now, when both options are given, it prints
824        counts only for those files that have at least one match. (GNU grep just
825        prints the file name in this circumstance, but including the count seems
826        more useful - otherwise, why use --count?) Also ensured that the
827        combination -clh just lists non-zero counts, with no names.
828    
829    4.  The long form of the pcregrep -F option was incorrectly implemented as
830        --fixed_strings instead of --fixed-strings. This is an incompatible change,
831        but it seems right to fix it, and I didn't think it was worth preserving
832        the old behaviour.
833    
834    5.  The command line items --regex=pattern and --regexp=pattern were not
835        recognized by pcregrep, which required --regex pattern or --regexp pattern
836        (with a space rather than an '='). The man page documented the '=' forms,
837        which are compatible with GNU grep; these now work.
838    
839    6.  No libpcreposix.pc file was created for pkg-config; there was just
840        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
841    
842    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
843        when UCP support is not needed, by modifying the Python script that
844        generates it from Unicode data files. This should not matter if the module
845        is correctly used as a library, but I received one complaint about 50K of
846        unwanted data. My guess is that the person linked everything into his
847        program rather than using a library. Anyway, it does no harm.
848    
849    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
850        was a minimum greater than 1 for a wide character in a possessive
851        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
852        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
853        character. Chaos in the form of incorrect output or a compiling loop could
854        result.
855    
856    9.  The restrictions on what a pattern can contain when partial matching is
857        requested for pcre_exec() have been removed. All patterns can now be
858        partially matched by this function. In addition, if there are at least two
859        slots in the offset vector, the offset of the earliest inspected character
860        for the match and the offset of the end of the subject are set in them when
861        PCRE_ERROR_PARTIAL is returned.
862    
863    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
864        synonymous with PCRE_PARTIAL, for backwards compatibility, and
865        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
866        and may be more useful for multi-segment matching.
867    
868    11. Partial matching with pcre_exec() is now more intuitive. A partial match
869        used to be given if ever the end of the subject was reached; now it is
870        given only if matching could not proceed because another character was
871        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
872        string "Z", which now yields "no match" instead of "partial match". In the
873        case of pcre_dfa_exec(), "no match" is given if every matching path for the
874        final character ended with (*FAIL).
875    
876    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
877        if the pattern had a "must contain" character that was already found in the
878        earlier partial match, unless partial matching was again requested. For
879        example, with the pattern /dog.(body)?/, the "must contain" character is
880        "g". If the first part-match was for the string "dog", restarting with
881        "sbody" failed. This bug has been fixed.
882    
883    13. The string returned by pcre_dfa_exec() after a partial match has been
884        changed so that it starts at the first inspected character rather than the
885        first character of the match. This makes a difference only if the pattern
886        starts with a lookbehind assertion or \b or \B (\K is not supported by
887        pcre_dfa_exec()). It's an incompatible change, but it makes the two
888        matching functions compatible, and I think it's the right thing to do.
889    
890    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
891        so that the demonstration program is easily available in environments where
892        PCRE has not been installed from source.
893    
894    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
895        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
896        library.
897    
898    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
899        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
900        is not the first non-POSIX option to be added. Clearly some people find
901        these options useful.
902    
903    17. If a caller to the POSIX matching function regexec() passes a non-zero
904        value for nmatch with a NULL value for pmatch, the value of
905        nmatch is forced to zero.
906    
907    18. RunGrepTest did not have a test for the availability of the -u option of
908        the diff command, as RunTest does. It now checks in the same way as
909        RunTest, and also checks for the -b option.
910    
911    19. If an odd number of negated classes containing just a single character
912        interposed, within parentheses, between a forward reference to a named
913        subpattern and the definition of the subpattern, compilation crashed with
914        an internal error, complaining that it could not find the referenced
915        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
916        [The bug was that it was starting one character too far in when skipping
917        over the character class, thus treating the ] as data rather than
918        terminating the class. This meant it could skip too much.]
919    
920    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
921        /g option in pcretest when the pattern contains \K, which makes it possible
922        to have an empty string match not at the start, even when the pattern is
923        anchored. Updated pcretest and pcredemo to use this option.
924    
925    21. If the maximum number of capturing subpatterns in a recursion was greater
926        than the maximum at the outer level, the higher number was returned, but
927        with unset values at the outer level. The correct (outer level) value is
928        now given.
929    
930    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
931        PCRE did not set those parentheses (unlike Perl). I have now found a way to
932        make it do so. The string so far is captured, making this feature
933        compatible with Perl.
934    
935    23. The tests have been re-organized, adding tests 11 and 12, to make it
936        possible to check the Perl 5.10 features against Perl 5.10.
937    
938    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
939        pattern matches a fixed length string. PCRE did not allow this; now it
940        does. Neither allows recursion.
941    
942    25. I finally figured out how to implement a request to provide the minimum
943        length of subject string that was needed in order to match a given pattern.
944        (It was back references and recursion that I had previously got hung up
945        on.) This code has now been added to pcre_study(); it finds a lower bound
946        to the length of subject needed. It is not necessarily the greatest lower
947        bound, but using it to avoid searching strings that are too short does give
948        some useful speed-ups. The value is available to calling programs via
949        pcre_fullinfo().
950    
951    26. While implementing 25, I discovered to my embarrassment that pcretest had
952        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
953        study optimizations had never been tested with that matching function.
954        Oops. What is worse, even when it was passed study data, there was a bug in
955        pcre_dfa_exec() that meant it never actually used it. Double oops. There
956        were also very few tests of studied patterns with pcre_dfa_exec().
957    
958    27. If (?| is used to create subpatterns with duplicate numbers, they are now
959        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
960        on the other side of the coin, they are no longer allowed to have different
961        names, because these cannot be distinguished in PCRE, and this has caused
962        confusion. (This is a difference from Perl.)
963    
964    28. When duplicate subpattern names are present (necessarily with different
965        numbers, as required by 27 above), and a test is made by name in a
966        conditional pattern, either for a subpattern having been matched, or for
967        recursion in such a pattern, all the associated numbered subpatterns are
968        tested, and the overall condition is true if the condition is true for any
969        one of them. This is the way Perl works, and is also more like the way
970        testing by number works.
971    
972    
973    Version 7.9 11-Apr-09
974    ---------------------
975    
976    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
977        (pcretest), all targets were linked against these libraries. This included
978        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
979        libraries. This caused unwanted dependencies to be created. This problem
980        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
981        pcretest is linked with readline.
982    
983    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
984        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
985        moved outside it again, because FALSE and TRUE are already defined in AIX,
986        but BOOL is not.
987    
988    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
989        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
990    
991    4.  The pcregrep documentation said spaces were inserted as well as colons (or
992        hyphens) following file names and line numbers when outputting matching
993        lines. This is not true; no spaces are inserted. I have also clarified the
994        wording for the --colour (or --color) option.
995    
996    5.  In pcregrep, when --colour was used with -o, the list of matching strings
997        was not coloured; this is different to GNU grep, so I have changed it to be
998        the same.
999    
1000    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1001        each matching line was coloured. Now it goes on to look for further matches
1002        of any of the test patterns, which is the same behaviour as GNU grep.
1003    
1004    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1005        doesn't make sense to accept an empty string match in pcregrep, so I have
1006        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1007        seems to be how GNU grep behaves.
1008    
1009    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1010        start or after a newline", because the conditional assertion was not being
1011        correctly handled. The rule now is that both the assertion and what follows
1012        in the first alternative must satisfy the test.
1013    
1014    9.  If auto-callout was enabled in a pattern with a conditional group whose
1015        condition was an assertion, PCRE could crash during matching, both with
1016        pcre_exec() and pcre_dfa_exec().
1017    
1018    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1019        used for matching.
1020    
1021    11. Unicode property support in character classes was not working for
1022        characters (bytes) greater than 127 when not in UTF-8 mode.
1023    
1024    12. Added the -M command line option to pcretest.
1025    
1026    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1027    
1028    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1029    
1030    16. Added comments and documentation about mis-use of no_arg in the C++
1031        wrapper.
1032    
1033    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1034        from Martin Jerabek that uses macro names for all relevant character and
1035        string constants.
1036    
1037    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1038        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1039        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1040        these, but not everybody uses configure.
1041    
1042    19. A conditional group that had only one branch was not being correctly
1043        recognized as an item that could match an empty string. This meant that an
1044        enclosing group might also not be so recognized, causing infinite looping
1045        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1046        with the subject "ab", where knowledge that the repeated group can match
1047        nothing is needed in order to break the loop.
1048    
1049    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1050        exec(), but without supplying a callout function, matching went wrong.
1051    
1052    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1053        leak if the size of the offset vector was greater than 30. When the vector
1054        is smaller, the saved offsets during recursion go onto a local stack
1055        vector, but for larger vectors malloc() is used. It was failing to free
1056        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1057        error, in fact).
1058    
1059    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1060        heapframe that is used only when UTF-8 support is enabled. This caused no
1061        problem, but was untidy.
1062    
1063    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1064        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1065        included within another project.
1066    
1067    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1068        slightly modified by me:
1069    
1070          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1071              not building pcregrep.
1072    
1073          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1074              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1075    
1076    25. Forward references, both numeric and by name, in patterns that made use of
1077        duplicate group numbers, could behave incorrectly or give incorrect errors,
1078        because when scanning forward to find the reference group, PCRE was not
1079        taking into account the duplicate group numbers. A pattern such as
1080        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1081    
1082    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1083        the feature of a custom pointer more persuasive (as requested by a user).
1084    
1085    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1086        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1087        pre-defined.
1088    
1089    28. Added support for (*UTF8) at the start of a pattern.
1090    
1091    29. Arrange for flags added by the "release type" setting in CMake to be shown
1092        in the configuration summary.
1093    
1094    
1095    Version 7.8 05-Sep-08
1096    ---------------------
1097    
1098    1.  Replaced UCP searching code with optimized version as implemented for Ad
1099        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1100        stage table and inline lookup instead of a function, giving speed ups of 2
1101        to 5 times on some simple patterns that I tested. Permission was given to
1102        distribute the MultiStage2.py script that generates the tables (it's not in
1103        the tarball, but is in the Subversion repository).
1104    
1105    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1106        scripts.
1107    
1108    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1109        a group with a zero qualifier. The result of the study could be incorrect,
1110        or the function might crash, depending on the pattern.
1111    
1112    4.  Caseless matching was not working for non-ASCII characters in back
1113        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1114        It now works when Unicode Property Support is available.
1115    
1116    5.  In pcretest, an escape such as \x{de} in the data was always generating
1117        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1118        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1119        truncation.
1120    
1121    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1122    
1123    7.  Added two (int) casts to pcregrep when printing the difference of two
1124        pointers, in case they are 64-bit values.
1125    
1126    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1127        test 2 if it fails.
1128    
1129    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1130        and a #define of that name to empty if it is not externally set. This is to
1131        allow users of MSVC to set it if necessary.
1132    
1133    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1134        the convenience functions in the pcre_get.c source file.
1135    
1136    11. An option change at the start of a pattern that had top-level alternatives
1137        could cause overwriting and/or a crash. This command provoked a crash in
1138        some environments:
1139    
1140          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1141    
1142        This potential security problem was recorded as CVE-2008-2371.
1143    
1144    12. For a pattern where the match had to start at the beginning or immediately
1145        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1146        pcre_dfa_exec() could read past the end of the passed subject if there was
1147        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1148        pcretest so that it places the subject at the end of its malloc-ed buffer.
1149    
1150    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1151        exec() might read past the end of the data buffer in UTF-8 mode.
1152    
1153    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1154        the data contained the byte 0x85 as part of a UTF-8 character within its
1155        first line. This applied both to normal and DFA matching.
1156    
1157    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1158        /^[^d]*?$/8 failed to match "abc".
1159    
1160    16. Added a missing copyright notice to pcrecpp_internal.h.
1161    
1162    17. Make it more clear in the documentation that values returned from
1163        pcre_exec() in ovector are byte offsets, not character counts.
1164    
1165    18. Tidied a few places to stop certain compilers from issuing warnings.
1166    
1167    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1168        supplied by Stefan Weber. I made a further small update for 7.8 because
1169        there is a change of source arrangements: the pcre_searchfuncs.c module is
1170        replaced by pcre_ucd.c.
1171    
1172    
1173    Version 7.7 07-May-08
1174    ---------------------
1175    
1176    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1177        a string to a long long, pretend we don't even have a long long." This is
1178        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1179    
1180    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1181        pre-7.6 versions, which defined a global no_arg variable instead of putting
1182        it in the RE class. (See also #8 below.)
1183    
1184    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1185        Lopes.
1186    
1187    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1188    
1189        (1) The include/exclude patterns were being applied to the whole pathnames
1190            of files, instead of just to the final components.
1191    
1192        (2) If there was more than one level of directory, the subdirectories were
1193            skipped unless they satisfied the include/exclude conditions. This is
1194            inconsistent with GNU grep (and could even be seen as contrary to the
1195            pcregrep specification - which I improved to make it absolutely clear).
1196            The action now is always to scan all levels of directory, and just
1197            apply the include/exclude patterns to regular files.
1198    
1199    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1200        --exclude_dir in the tests to avoid scanning .svn directories.
1201    
1202    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1203        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1204        doesn't support NULs in patterns.
1205    
1206    7.  Added some missing "const"s to declarations of static tables in
1207        pcre_compile.c and pcre_dfa_exec.c.
1208    
1209    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1210        caused by fix #2  above. (Subsequently also a second patch to fix the
1211        first patch. And a third patch - this was a messy problem.)
1212    
1213    9.  Applied Craig's patch to remove the use of push_back().
1214    
1215    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1216        matching function regexec().
1217    
1218    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1219        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1220        references. PCRE supports relative numbers with this syntax (I don't think
1221        Oniguruma does).
1222    
1223    12. Previously, a group with a zero repeat such as (...){0} was completely
1224        omitted from the compiled regex. However, this means that if the group
1225        was called as a subroutine from elsewhere in the pattern, things went wrong
1226        (an internal error was given). Such groups are now left in the compiled
1227        pattern, with a new opcode that causes them to be skipped at execution
1228        time.
1229    
1230    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1231        to the way PCRE behaves:
1232    
1233        (a) A lone ] character is dis-allowed (Perl treats it as data).
1234    
1235        (b) A back reference to an unmatched subpattern matches an empty string
1236            (Perl fails the current match path).
1237    
1238        (c) A data ] in a character class must be notated as \] because if the
1239            first data character in a class is ], it defines an empty class. (In
1240            Perl it is not possible to have an empty class.) The empty class []
1241            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1242            The negative empty class [^] matches any one character, independently
1243            of the DOTALL setting.
1244    
1245    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1246        non-existent subpattern following a character class starting with ']' and
1247        containing () gave an internal compiling error instead of "reference to
1248        non-existent subpattern". Fortunately, when the pattern did exist, the
1249        compiled code was correct. (When scanning forwards to check for the
1250        existencd of the subpattern, it was treating the data ']' as terminating
1251        the class, so got the count wrong. When actually compiling, the reference
1252        was subsequently set up correctly.)
1253    
1254    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1255        it was being rejected as not supported by pcre_dfa_exec(), even though
1256        other assertions are supported. I have made pcre_dfa_exec() support
1257        (*FAIL).
1258    
1259    16. The implementation of 13c above involved the invention of a new opcode,
1260        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1261        cannot be changed at match time, I realized I could make a small
1262        improvement to matching performance by compiling OP_ALLANY instead of
1263        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1264        on the OP_ANY path.
1265    
1266    17. Compiling pcretest on Windows with readline support failed without the
1267        following two fixes: (1) Make the unistd.h include conditional on
1268        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1269    
1270    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1271        ncurses library to be included for pcretest when ReadLine support is
1272        requested, but also to allow for it to be overridden. This patch came from
1273        Daniel Bergström.
1274    
1275    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1276        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1277        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1278        spotting this.
1279    
1280    
1281    Version 7.6 28-Jan-08
1282    ---------------------
1283    
1284    1.  A character class containing a very large number of characters with
1285        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1286        overflow.
1287    
1288    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1289        HAVE_LONG_LONG is not defined.
1290    
1291    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1292        bring them up to date and include new features. This patch includes:
1293    
1294        - Fixed PH's badly added libz and libbz2 support.
1295        - Fixed a problem with static linking.
1296        - Added pcredemo. [But later removed - see 7 below.]
1297        - Fixed dftables problem and added an option.
1298        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1299            HAVE_LONG_LONG.
1300        - Added readline support for pcretest.
1301        - Added an listing of the option settings after cmake has run.
1302    
1303    4.  A user submitted a patch to Makefile that makes it easy to create
1304        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1305        Makefile.am that cause it to include this special target, without
1306        affecting anything else. Note that the same mingw target plus all
1307        the other distribution libraries and programs are now supported
1308        when configuring with CMake (see 6 below) instead of with
1309        Configure/Make.
1310    
1311    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1312        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1313        exported in the Windows port". It has not yet been confirmed that the patch
1314        solves the problem, but it does no harm.
1315    
1316    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1317        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1318        with CMake, and also correct the comment about stack recursion.
1319    
1320    7.  Remove the automatic building of pcredemo from the ./configure system and
1321        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1322        of a program that users should build themselves after PCRE is installed, so
1323        building it automatically is not really right. What is more, it gave
1324        trouble in some build environments.
1325    
1326    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1327    
1328    
1329    Version 7.5 10-Jan-08
1330  ---------------------  ---------------------
1331    
1332  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
# Line 99  Version 7.5 23-Dec-07 Line 1424  Version 7.5 23-Dec-07
1424    
1425  20. In pcrecpp.cc, the variable 'count' was incremented twice in  20. In pcrecpp.cc, the variable 'count' was incremented twice in
1426      RE::GlobalReplace(). As a result, the number of replacements returned was      RE::GlobalReplace(). As a result, the number of replacements returned was
1427      double what it should be. I have removed one of the increments.      double what it should be. I removed one of the increments, but Craig sent a
1428        later patch that removed the other one (the right fix) and added unit tests
1429        that check the return values (which was not done before).
1430    
1431  21. Several CMake things:  21. Several CMake things:
1432    
1433      (1) Arranged that, when cmake is used on Unix, the libraries end up with      (1) Arranged that, when cmake is used on Unix, the libraries end up with
1434          the names libpcre and libpcreposix.          the names libpcre and libpcreposix, not just pcre and pcreposix.
1435    
1436      (2) Arranged for pcretest and pcregrep to link with the newly-built      (2) The above change means that pcretest and pcregrep are now correctly
1437          libraries, not previously installed ones.          linked with the newly-built libraries, not previously installed ones.
1438    
1439      (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.      (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1440    
1441    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1442        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1443        UTF-8 newline character). The key issue is that the pattern starts .*;
1444        this means that the match must be either at the beginning, or after a
1445        newline. The bug was in the code for advancing after a failed match and
1446        checking that the new position followed a newline. It was not taking
1447        account of UTF-8 characters correctly.
1448    
1449    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1450        character classes. PCRE was not treating the sequence [:...:] as a
1451        character class unless the ... were all letters. Perl, however, seems to
1452        allow any characters between [: and :], though of course it rejects as
1453        unknown any "names" that contain non-letters, because all the known class
1454        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1455        for example, whereas PCRE did not - it did not recognize a POSIX character
1456        class. This seemed a bit dangerous, so the code has been changed to be
1457        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1458        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1459        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1460        Perl does, and where it didn't before.
1461    
1462    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1463        Windows environments %n is disabled by default.
1464    
1465    
1466  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07

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