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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.00 ??-???-??  Version 8.21
5    ------------
6    
7    1.  Updating the JIT compiler.
8    
9    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
10        are added as well.
11    
12    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
13        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
14        calling _pcre_jit_exec. Some extra comments are added.
15    
16    4.  Mark settings inside atomic groups that do not contain any capturing
17        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
18        was introduced by change 18 for 8.20.
19    
20    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
21        ECMA-262 standard.
22    
23    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
24        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
25        This bug was probably introduced by change 9 of 8.13.
26    
27    7.  While fixing 6 above, I noticed that a number of other items were being
28        incorrectly rejected as "not fixed length". This arose partly because newer
29        opcodes had not been added to the fixed-length checking code. I have (a)
30        corrected the bug and added tests for these items, and (b) arranged for an
31        error to occur if an unknown opcode is encountered while checking for fixed
32        length instead of just assuming "not fixed length". The items that were
33        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
34        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
35        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
36    
37    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
38        being incorrectly compiled and would have given unpredicatble results.
39    
40    9.  A possessively repeated subpattern with minimum repeat count greater than
41        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
42        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
43        the first (A) could occur when it should not.
44    
45    10. Add a cast and remove a redundant test from the code.
46    
47    11. JIT should use pcre_malloc/pcre_free for allocation.
48    
49    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
50        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
51        is anything other than /usr, -L is still shown).
52    
53    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
54    
55    
56    Version 8.20 21-Oct-2011
57    ------------------------
58    
59    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
60        a POSIX class. After further experiments with Perl, which convinced me that
61        Perl has bugs and confusions, a closing square bracket is no longer allowed
62        in a POSIX name. This bug also affected patterns with classes that started
63        with full stops.
64    
65    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
66        captured substring, but while checking the failing first alternative,
67        substring 1 is temporarily captured. If the output vector supplied to
68        pcre_exec() was not big enough for this capture, the yield of the function
69        was still zero ("insufficient space for captured substrings"). This cannot
70        be totally fixed without adding another stack variable, which seems a lot
71        of expense for a edge case. However, I have improved the situation in cases
72        such as /(a)(b)x|abc/ matched against "abc", where the return code
73        indicates that fewer than the maximum number of slots in the ovector have
74        been set.
75    
76    3.  Related to (2) above: when there are more back references in a pattern than
77        slots in the output vector, pcre_exec() uses temporary memory during
78        matching, and copies in the captures as far as possible afterwards. It was
79        using the entire output vector, but this conflicts with the specification
80        that only 2/3 is used for passing back captured substrings. Now it uses
81        only the first 2/3, for compatibility. This is, of course, another edge
82        case.
83    
84    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
85        main code base, and can be used by building with --enable-jit. When this is
86        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
87        runtime --no-jit option is given.
88    
89    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
90        ovector, the return from the function was zero, implying that there were
91        other matches that did not fit. The correct "exactly full" value is now
92        returned.
93    
94    6.  If a subpattern that was called recursively or as a subroutine contained
95        (*PRUNE) or any other control that caused it to give a non-standard return,
96        invalid errors such as "Error -26 (nested recursion at the same subject
97        position)" or even infinite loops could occur.
98    
99    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
100        computing the minimum length on reaching *ACCEPT, and so ended up with the
101        wrong value of 1 rather than 0. Further investigation indicates that
102        computing a minimum subject length in the presence of *ACCEPT is difficult
103        (think back references, subroutine calls), and so I have changed the code
104        so that no minimum is registered for a pattern that contains *ACCEPT.
105    
106    8.  If (*THEN) was present in the first (true) branch of a conditional group,
107        it was not handled as intended. [But see 16 below.]
108    
109    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
110        Sheri Pierce.
111    
112    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
113        the first byte in a match must be "a".
114    
115    11. Change 17 for 8.13 increased the recursion depth for patterns like
116        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
117        pattern contains any instances of (*THEN). If it does not, the old
118        optimizations are restored. It would be nice to do this on a per-group
119        basis, but at the moment that is not feasible.
120    
121    12. In some environments, the output of pcretest -C is CRLF terminated. This
122        broke RunTest's code that checks for the link size. A single white space
123        character after the value is now allowed for.
124    
125    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
126        For "fr", it uses the Windows-specific input and output files.
127    
128    14. If (*THEN) appeared in a group that was called recursively or as a
129        subroutine, it did not work as intended. [But see next item.]
130    
131    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
132        pattern fragments (but not containing any | characters). If A and B are
133        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
134        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
135        D. In other words, Perl considers parentheses that do not contain any |
136        characters to be part of a surrounding alternative, whereas PCRE was
137        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
138        differently. PCRE now behaves in the same way as Perl, except in the case
139        of subroutine/recursion calls such as (?1) which have in any case always
140        been different (but PCRE had them first :-).
141    
142    16. Related to 15 above: Perl does not treat the | in a conditional group as
143        creating alternatives. Such a group is treated in the same way as an
144        ordinary group without any | characters when processing (*THEN). PCRE has
145        been changed to match Perl's behaviour.
146    
147    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
148        RunGrepTest script failed.
149    
150    18. Change 22 for version 13 caused atomic groups to use more stack. This is
151        inevitable for groups that contain captures, but it can lead to a lot of
152        stack use in large patterns. The old behaviour has been restored for atomic
153        groups that do not contain any capturing parentheses.
154    
155    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
156        suppress the check for a minimum subject length at run time. (If it was
157        given to pcre_exec() or pcre_dfa_exec() it did work.)
158    
159    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
160        fail to work when decoding hex characters in data strings in EBCDIC
161        environments.
162    
163    21. It appears that in at least one Mac OS environment, the isxdigit() function
164        is implemented as a macro that evaluates to its argument more than once,
165        contravening the C 90 Standard (I haven't checked a later standard). There
166        was an instance in pcretest which caused it to go wrong when processing
167        \x{...} escapes in subject strings. The has been rewritten to avoid using
168        things like p++ in the argument of isxdigit().
169    
170    
171    Version 8.13 16-Aug-2011
172    ------------------------
173    
174    1.  The Unicode data tables have been updated to Unicode 6.0.0.
175    
176    2.  Two minor typos in pcre_internal.h have been fixed.
177    
178    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
179        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
180        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
181    
182    4.  There were a number of related bugs in the code for matching backrefences
183        caselessly in UTF-8 mode when codes for the characters concerned were
184        different numbers of bytes. For example, U+023A and U+2C65 are an upper
185        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
186        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
187        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
188        2-byte code at the end of the subject (it thought there wasn't enough data
189        left).
190    
191    5.  Comprehensive information about what went wrong is now returned by
192        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
193        as the output vector has at least 2 elements. The offset of the start of
194        the failing character and a reason code are placed in the vector.
195    
196    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
197        now returned is for the first byte of the failing character, instead of the
198        last byte inspected. This is an incompatible change, but I hope it is small
199        enough not to be a problem. It makes the returned offset consistent with
200        pcre_exec() and pcre_dfa_exec().
201    
202    7.  pcretest now gives a text phrase as well as the error number when
203        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
204        failure, the offset and reason code are output.
205    
206    8.  When \R was used with a maximizing quantifier it failed to skip backwards
207        over a \r\n pair if the subsequent match failed. Instead, it just skipped
208        back over a single character (\n). This seems wrong (because it treated the
209        two characters as a single entity when going forwards), conflicts with the
210        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
211        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
212        has been changed.
213    
214    9.  Some internal refactoring has changed the processing so that the handling
215        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
216        time (the PCRE_DOTALL option was changed this way some time ago: version
217        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
218        which was always a bit of a fudge. It also means that there is one less
219        argument for the match() function, which reduces its stack requirements
220        slightly. This change also fixes an incompatibility with Perl: the pattern
221        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
222    
223    10. More internal refactoring has drastically reduced the number of recursive
224        calls to match() for possessively repeated groups such as (abc)++ when
225        using pcre_exec().
226    
227    11. While implementing 10, a number of bugs in the handling of groups were
228        discovered and fixed:
229    
230        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
231        (a|)*(?1) gave a compile-time internal error.
232        ((a|)+)+  did not notice that the outer group could match an empty string.
233        (^a|^)+   was not marked as anchored.
234        (.*a|.*)+ was not marked as matching at start or after a newline.
235    
236    12. Yet more internal refactoring has removed another argument from the match()
237        function. Special calls to this function are now indicated by setting a
238        value in a variable in the "match data" data block.
239    
240    13. Be more explicit in pcre_study() instead of relying on "default" for
241        opcodes that mean there is no starting character; this means that when new
242        ones are added and accidentally left out of pcre_study(), testing should
243        pick them up.
244    
245    14. The -s option of pcretest has been documented for ages as being an old
246        synonym of -m (show memory usage). I have changed it to mean "force study
247        for every regex", that is, assume /S for every regex. This is similar to -i
248        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
249        using it. It makes it easier to run collections of tests with and without
250        study enabled, and thereby test pcre_study() more easily. All the standard
251        tests are now run with and without -s (but some patterns can be marked as
252        "never study" - see 20 below).
253    
254    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
255        restoration of the capturing data to the outer values was not happening
256        correctly.
257    
258    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
259        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
260        pattern had matched an empty string, and so incorrectly returned a no
261        match.
262    
263    17. There was optimizing code for the last branch of non-capturing parentheses,
264        and also for the obeyed branch of a conditional subexpression, which used
265        tail recursion to cut down on stack usage. Unfortunately, now that there is
266        the possibility of (*THEN) occurring in these branches, tail recursion is
267        no longer possible because the return has to be checked for (*THEN). These
268        two optimizations have therefore been removed. [But see 8.20/11 above.]
269    
270    18. If a pattern containing \R was studied, it was assumed that \R always
271        matched two bytes, thus causing the minimum subject length to be
272        incorrectly computed because \R can also match just one byte.
273    
274    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
275        was incorrectly computed.
276    
277    20. If /S is present twice on a test pattern in pcretest input, it now
278        *disables* studying, thereby overriding the use of -s on the command line
279        (see 14 above). This is necessary for one or two tests to keep the output
280        identical in both cases.
281    
282    21. When (*ACCEPT) was used in an assertion that matched an empty string and
283        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
284    
285    22. When an atomic group that contained a capturing parenthesis was
286        successfully matched, but the branch in which it appeared failed, the
287        capturing was not being forgotten if a higher numbered group was later
288        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
289        group 1 to "a", when in fact it should be unset. This applied to multi-
290        branched capturing and non-capturing groups, repeated or not, and also to
291        positive assertions (capturing in negative assertions does not happen
292        in PCRE) and also to nested atomic groups.
293    
294    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
295        subject after a captured substring, to make it easier to tell which of a
296        number of identical substrings has been captured.
297    
298    24. The way atomic groups are processed by pcre_exec() has been changed so that
299        if they are repeated, backtracking one repetition now resets captured
300        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
301        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
302        "aaa". Previously, it would have been "a". As part of this code
303        refactoring, the way recursive calls are handled has also been changed.
304    
305    25. If an assertion condition captured any substrings, they were not passed
306        back unless some other capturing happened later. For example, if
307        (?(?=(a))a) was matched against "a", no capturing was returned.
308    
309    26. When studying a pattern that contained subroutine calls or assertions,
310        the code for finding the minimum length of a possible match was handling
311        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
312        group 1 called group 2 while simultaneously a separate group 2 called group
313        1). A stack overflow occurred in this case. I have fixed this by limiting
314        the recursion depth to 10.
315    
316    27. Updated RunTest.bat in the distribution to the version supplied by Tom
317        Fortmann. This supports explicit test numbers on the command line, and has
318        argument validation and error reporting.
319    
320    28. An instance of \X with an unlimited repeat could fail if at any point the
321        first character it looked at was a mark character.
322    
323    29. Some minor code refactoring concerning Unicode properties and scripts
324        should reduce the stack requirement of match() slightly.
325    
326    30. Added the '=' option to pcretest to check the setting of unused capturing
327        slots at the end of the pattern, which are documented as being -1, but are
328        not included in the return count.
329    
330    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
331        compiled something random. Now it gives a compile-time error (as does
332        Perl).
333    
334    32. A *MARK encountered during the processing of a positive assertion is now
335        recorded and passed back (compatible with Perl).
336    
337    33. If --only-matching or --colour was set on a pcregrep call whose pattern
338        had alternative anchored branches, the search for a second match in a line
339        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
340        matched the line "0102" twice. The same bug affected patterns that started
341        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
342        twice.
343    
344    34. Previously, PCRE did not allow quantification of assertions. However, Perl
345        does, and because of capturing effects, quantifying parenthesized
346        assertions may at times be useful. Quantifiers are now allowed for
347        parenthesized assertions.
348    
349    35. A minor code tidy in pcre_compile() when checking options for \R usage.
350    
351    36. \g was being checked for fancy things in a character class, when it should
352        just be a literal "g".
353    
354    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
355        appearance of a nested POSIX class supersedes an apparent external class.
356        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
357        unescaped square brackets may also appear as part of class names. For
358        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
359        more like Perl. (But see 8.20/1 above.)
360    
361    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
362        was because it thought it was \N{name}, which is not supported).
363    
364    39. Add minix to OS list not supporting the -S option in pcretest.
365    
366    40. PCRE tries to detect cases of infinite recursion at compile time, but it
367        cannot analyze patterns in sufficient detail to catch mutual recursions
368        such as ((?1))((?2)). There is now a runtime test that gives an error if a
369        subgroup is called recursively as a subpattern for a second time at the
370        same position in the subject string. In previous releases this might have
371        been caught by the recursion limit, or it might have run out of stack.
372    
373    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
374        happen only once. PCRE was, however incorrectly giving a compile time error
375        "recursive call could loop indefinitely" because it cannot analyze the
376        pattern in sufficient detail. The compile time test no longer happens when
377        PCRE is compiling a conditional subpattern, but actual runaway loops are
378        now caught at runtime (see 40 above).
379    
380    42. It seems that Perl allows any characters other than a closing parenthesis
381        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
382        has been changed to be the same.
383    
384    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
385        as not to get warnings when autogen.sh is called. Also changed
386        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
387    
388    44. To help people who use pcregrep to scan files containing exceedingly long
389        lines, the following changes have been made:
390    
391        (a) The default value of the buffer size parameter has been increased from
392            8K to 20K. (The actual buffer used is three times this size.)
393    
394        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
395            PCRE is built.
396    
397        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
398            to be set at run time.
399    
400        (d) Numerical values in pcregrep options can be followed by K or M, for
401            example --buffer-size=50K.
402    
403        (e) If a line being scanned overflows pcregrep's buffer, an error is now
404            given and the return code is set to 2.
405    
406    45. Add a pointer to the latest mark to the callout data block.
407    
408    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
409        partial match of an empty string instead of no match. This was specific to
410        the use of ".".
411    
412    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
413        complete match instead of a partial match. This bug was dependent on both
414        the PCRE_UTF8 and PCRE_DOTALL options being set.
415    
416    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
417        starting byte set, because \b was not being ignored.
418    
419    
420    Version 8.12 15-Jan-2011
421    ------------------------
422    
423    1.  Fixed some typos in the markup of the man pages, and wrote a script that
424        checks for such things as part of the documentation building process.
425    
426    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
427        --match-limit and --recursion-limit options (added for 8.11). In
428        particular, this made one of the standard tests fail. (The integer value
429        went into the wrong half of a long int.)
430    
431    3.  If the --colour option was given to pcregrep with -v (invert match), it
432        did strange things, either producing crazy output, or crashing. It should,
433        of course, ignore a request for colour when reporting lines that do not
434        match.
435    
436    4.  Another pcregrep bug caused similar problems if --colour was specified with
437        -M (multiline) and the pattern match finished with a line ending.
438    
439    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
440        matched in multiline mode, the following line was shown as part of the
441        match. This seems wrong, so I have changed it.
442    
443    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
444        the check for further matches in the same line (so they could be coloured)
445        to overrun the end of the current line. If another match was found, it was
446        incorrectly shown (and then shown again when found in the next line).
447    
448    7.  If pcregrep was compiled under Windows, there was a reference to the
449        function pcregrep_exit() before it was defined. I am assuming this was
450        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
451        reported by a user. I've moved the definition above the reference.
452    
453    
454    Version 8.11 10-Dec-2010
455    ------------------------
456    
457    1.  (*THEN) was not working properly if there were untried alternatives prior
458        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
459        backtracked to try for "b" instead of moving to the next alternative branch
460        at the same level (in this case, to look for "c"). The Perl documentation
461        is clear that when (*THEN) is backtracked onto, it goes to the "next
462        alternative in the innermost enclosing group".
463    
464    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
465        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
466        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
467        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
468        (*THEN).
469    
470    3.  If \s appeared in a character class, it removed the VT character from
471        the class, even if it had been included by some previous item, for example
472        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
473        of \s, but is part of the POSIX "space" class.)
474    
475    4.  A partial match never returns an empty string (because you can always
476        match an empty string at the end of the subject); however the checking for
477        an empty string was starting at the "start of match" point. This has been
478        changed to the "earliest inspected character" point, because the returned
479        data for a partial match starts at this character. This means that, for
480        example, /(?<=abc)def/ gives a partial match for the subject "abc"
481        (previously it gave "no match").
482    
483    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
484        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
485        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
486        has an implication that the given string is incomplete (because a partial
487        match is preferred over a full match). For this reason, these items now
488        give a partial match in this situation. [Aside: previously, the one case
489        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
490        match rather than a full match, which was wrong by the old rules, but is
491        now correct.]
492    
493    6.  There was a bug in the handling of #-introduced comments, recognized when
494        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
495        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
496        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
497        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
498        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
499        places in pcre_compile().
500    
501    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
502        comments when looking ahead for named forward references to subpatterns,
503        the only newline sequence it recognized was NL. It now handles newlines
504        according to the set newline convention.
505    
506    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
507        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
508        cater for a lack of strerror(). These oversights have been fixed.
509    
510    9.  Added --match-limit and --recursion-limit to pcregrep.
511    
512    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
513    
514    11. When the -o option was used, pcregrep was setting a return code of 1, even
515        when matches were found, and --line-buffered was not being honoured.
516    
517    12. Added an optional parentheses number to the -o and --only-matching options
518        of pcregrep.
519    
520    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
521        can match an empty string. The code to do it in pcretest and pcredemo
522        needed fixing:
523    
524        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
525            only one byte after an empty string match just before CRLF (this case
526            just got forgotten; "any" and "anycrlf" were OK).
527    
528        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
529            mode when an empty string match preceded an ASCII character followed by
530            a non-ASCII character. (The code for advancing by one character rather
531            than one byte was nonsense.)
532    
533        (c) The pcredemo.c sample program did not have any code at all to handle
534            the cases when CRLF is a valid newline sequence.
535    
536    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
537        as a starting offset was within the subject string. There is now a new
538        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
539        negative or greater than the length of the string. In order to test this,
540        pcretest is extended to allow the setting of negative starting offsets.
541    
542    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
543        starting offset points to the beginning of a UTF-8 character was
544        unnecessarily clumsy. I tidied it up.
545    
546    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
547        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
548    
549    17. Nobody had reported that the --include_dir option, which was added in
550        release 7.7 should have been called --include-dir (hyphen, not underscore)
551        for compatibility with GNU grep. I have changed it to --include-dir, but
552        left --include_dir as an undocumented synonym, and the same for
553        --exclude-dir, though that is not available in GNU grep, at least as of
554        release 2.5.4.
555    
556    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
557        characters from a string of bytes) have been redefined so as not to use
558        loops, in order to improve performance in some environments. At the same
559        time, I abstracted some of the common code into auxiliary macros to save
560        repetition (this should not affect the compiled code).
561    
562    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
563        compile-time error is now given if \c is not followed by an ASCII
564        character, that is, a byte less than 128. (In EBCDIC mode, the code is
565        different, and any byte value is allowed.)
566    
567    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
568        START_OPTIMIZE option, which is now allowed at compile time - but just
569        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
570        to pcregrep and other applications that have no direct access to PCRE
571        options. The new /Y option in pcretest sets this option when calling
572        pcre_compile().
573    
574    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
575        back references. Groups containing recursive back references were forced to
576        be atomic by that change, but in the case of named groups, the amount of
577        memory required was incorrectly computed, leading to "Failed: internal
578        error: code overflow". This has been fixed.
579    
580    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
581        pcretest.c, to avoid build problems in some Borland environments.
582    
583    
584    Version 8.10 25-Jun-2010
585    ------------------------
586    
587    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
588        THEN.
589    
590    2.  (*ACCEPT) was not working when inside an atomic group.
591    
592    3.  Inside a character class, \B is treated as a literal by default, but
593        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
594        causes the error). The code is unchanged, but I tidied the documentation.
595    
596    4.  Inside a character class, PCRE always treated \R and \X as literals,
597        whereas Perl faults them if its -w option is set. I have changed PCRE so
598        that it faults them when PCRE_EXTRA is set.
599    
600    5.  Added support for \N, which always matches any character other than
601        newline. (It is the same as "." when PCRE_DOTALL is not set.)
602    
603    6.  When compiling pcregrep with newer versions of gcc which may have
604        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
605        declared with attribute warn_unused_result" were given. Just casting the
606        result to (void) does not stop the warnings; a more elaborate fudge is
607        needed. I've used a macro to implement this.
608    
609    7.  Minor change to pcretest.c to avoid a compiler warning.
610    
611    8.  Added four artifical Unicode properties to help with an option to make
612        \s etc use properties (see next item). The new properties are: Xan
613        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
614    
615    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
616        use Unicode properties. (*UCP) at the start of a pattern can be used to set
617        this option. Modified pcretest to add /W to test this facility. Added
618        REG_UCP to make it available via the POSIX interface.
619    
620    10. Added --line-buffered to pcregrep.
621    
622    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
623        studied, and the match started with a letter with a code point greater than
624        127 whose first byte was different to the first byte of the other case of
625        the letter, the other case of this starting letter was not recognized
626        (#976).
627    
628    12. If a pattern that was studied started with a repeated Unicode property
629        test, for example, \p{Nd}+, there was the theoretical possibility of
630        setting up an incorrect bitmap of starting bytes, but fortunately it could
631        not have actually happened in practice until change 8 above was made (it
632        added property types that matched character-matching opcodes).
633    
634    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
635        possible starting bytes for non-anchored patterns.
636    
637    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
638        \R, and also a number of cases that involve Unicode properties, both
639        explicit and implicit when PCRE_UCP is set.
640    
641    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
642        input, it could crash or give wrong results if characters with values
643        greater than 0xc0 were present in the subject string. (Detail: it assumed
644        UTF-8 input when processing these items.)
645    
646    16. Added a lot of (int) casts to avoid compiler warnings in systems where
647        size_t is 64-bit (#991).
648    
649    17. Added a check for running out of memory when PCRE is compiled with
650        --disable-stack-for-recursion (#990).
651    
652    18. If the last data line in a file for pcretest does not have a newline on
653        the end, a newline was missing in the output.
654    
655    19. The default pcre_chartables.c file recognizes only ASCII characters (values
656        less than 128) in its various bitmaps. However, there is a facility for
657        generating tables according to the current locale when PCRE is compiled. It
658        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
659        characters, are recognized by isspace() and therefore were getting set in
660        these tables, and indeed these tables seem to approximate to ISO 8859. This
661        caused a problem in UTF-8 mode when pcre_study() was used to create a list
662        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
663        which of course cannot start UTF-8 characters. I have changed the code so
664        that only real ASCII characters (less than 128) and the correct starting
665        bytes for UTF-8 encodings are set for characters greater than 127 when in
666        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
667        altogether.)
668    
669    20. Added the /T option to pcretest so as to be able to run tests with non-
670        standard character tables, thus making it possible to include the tests
671        used for 19 above in the standard set of tests.
672    
673    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
674        reference to a subpattern the other side of a comment that contains an
675        opening parenthesis caused either an internal compiling error, or a
676        reference to the wrong subpattern.
677    
678    
679    Version 8.02 19-Mar-2010
680    ------------------------
681    
682    1.  The Unicode data tables have been updated to Unicode 5.2.0.
683    
684    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
685        configured.
686    
687    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
688        original author of that file, following a query about its status.
689    
690    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
691        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
692    
693    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
694        quantifier applied to a forward-referencing subroutine call, could compile
695        incorrect code or give the error "internal error: previously-checked
696        referenced subpattern not found".
697    
698    6.  Both MS Visual Studio and Symbian OS have problems with initializing
699        variables to point to external functions. For these systems, therefore,
700        pcre_malloc etc. are now initialized to local functions that call the
701        relevant global functions.
702    
703    7.  There were two entries missing in the vectors called coptable and poptable
704        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
705        I've fixed the data, and added a kludgy way of testing at compile time that
706        the lengths are correct (equal to the number of opcodes).
707    
708    8.  Following on from 7, I added a similar kludge to check the length of the
709        eint vector in pcreposix.c.
710    
711    9.  Error texts for pcre_compile() are held as one long string to avoid too
712        much relocation at load time. To find a text, the string is searched,
713        counting zeros. There was no check for running off the end of the string,
714        which could happen if a new error number was added without updating the
715        string.
716    
717    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
718    
719    11. \K was not working if it appeared in an atomic group or in a group that
720        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
721        \K is "not well defined" if used in an assertion. PCRE now accepts it if
722        the assertion is positive, but not if it is negative.
723    
724    12. Change 11 fortuitously reduced the size of the stack frame used in the
725        "match()" function of pcre_exec.c by one pointer. Forthcoming
726        implementation of support for (*MARK) will need an extra pointer on the
727        stack; I have reserved it now, so that the stack frame size does not
728        decrease.
729    
730    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
731        item in branch that calls a recursion is a subroutine call - as in the
732        second branch in the above example - was incorrectly given the compile-
733        time error "recursive call could loop indefinitely" because pcre_compile()
734        was not correctly checking the subroutine for matching a non-empty string.
735    
736    14. The checks for overrunning compiling workspace could trigger after an
737        overrun had occurred. This is a "should never occur" error, but it can be
738        triggered by pathological patterns such as hundreds of nested parentheses.
739        The checks now trigger 100 bytes before the end of the workspace.
740    
741    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
742    
743    
744    Version 8.01 19-Jan-2010
745    ------------------------
746    
747    1.  If a pattern contained a conditional subpattern with only one branch (in
748        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
749        computed the wrong minimum data length (which is of course zero for such
750        subpatterns). This could cause incorrect "no match" results.
751    
752    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
753        the pattern is reset in the first branch, pcre_compile() failed with
754        "internal error: code overflow at offset...". This happened only when
755        the reset was to the original external option setting. (An optimization
756        abstracts leading options settings into an external setting, which was the
757        cause of this.)
758    
759    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
760        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
761        assertion pattern did not match (meaning that the assertion was true), it
762        was incorrectly treated as false if the SKIP had been reached during the
763        matching. This also applied to assertions used as conditions.
764    
765    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
766        assertion subpattern, including such a pattern used as a condition,
767        unpredictable results occurred, instead of the error return
768        PCRE_ERROR_DFA_UITEM.
769    
770    5.  The C++ GlobalReplace function was not working like Perl for the special
771        situation when an empty string is matched. It now does the fancy magic
772        stuff that is necessary.
773    
774    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
775        removed. (These were left over from very, very early versions of PCRE.)
776    
777    7.  Some cosmetic changes to the code to make life easier when compiling it
778        as part of something else:
779    
780        (a) Change DEBUG to PCRE_DEBUG.
781    
782        (b) In pcre_compile(), rename the member of the "branch_chain" structure
783            called "current" as "current_branch", to prevent a collision with the
784            Linux macro when compiled as a kernel module.
785    
786        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
787            prevent a collision with the Linux macro when compiled as a kernel
788            module.
789    
790    8.  In pcre_compile() there are some checks for integer overflows that used to
791        cast potentially large values to (double). This has been changed to that
792        when building, a check for int64_t is made, and if it is found, it is used
793        instead, thus avoiding the use of floating point arithmetic. (There is no
794        other use of FP in PCRE.) If int64_t is not found, the fallback is to
795        double.
796    
797    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
798        2005 (difference between two addresses compared to an unsigned value).
799    
800    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
801        custom one, because of the following reported problem in Windows:
802    
803          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
804              under Win32.
805          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
806              therefore missing the function definition.
807          - The compiler thus generates a "C" signature for the test function.
808          - The linker fails to find the "C" function.
809          - PCRE fails to configure if asked to do so against libbz2.
810    
811    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
812        messages were output:
813    
814          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
815          rerunning libtoolize, to keep the correct libtool macros in-tree.
816          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
817    
818        I have done both of these things.
819    
820    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
821        most of the time, it *can* run out if it is given a pattern that contains a
822        runaway infinite recursion. I updated the discussion in the pcrestack man
823        page.
824    
825    13. Now that we have gone to the x.xx style of version numbers, the minor
826        version may start with zero. Using 08 or 09 is a bad idea because users
827        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
828        interpreted as invalid octal numbers. I've updated the previous comment in
829        configure.ac, and also added a check that gives an error if 08 or 09 are
830        used.
831    
832    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
833        causing partial matching to fail when the end of the subject matched \W
834        in a UTF-8 pattern where \W was quantified with a minimum of 3.
835    
836    15. There were some discrepancies between the declarations in pcre_internal.h
837        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
838        their definitions. The declarations used "const uschar *" and the
839        definitions used USPTR. Even though USPTR is normally defined as "const
840        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
841        reported that: "This difference in casting confuses some C++ compilers, for
842        example, SunCC recognizes above declarations as different functions and
843        generates broken code for hbpcre." I have changed the declarations to use
844        USPTR.
845    
846    16. GNU libtool is named differently on some systems. The autogen.sh script now
847        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
848        (FreeBSD).
849    
850    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
851        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
852        comment: "Figure out how to create a longlong from a string: strtoll and
853        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
854        instance, but it only takes 2 args instead of 3!"
855    
856    18. A subtle bug concerned with back references has been fixed by a change of
857        specification, with a corresponding code fix. A pattern such as
858        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
859        refers, was giving matches when it shouldn't. For example, xa=xaaa would
860        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
861        same bug. Such groups have to be quantified to be useful, or contained
862        inside another quantified group. (If there's no repetition, the reference
863        can never match.) The problem arises because, having left the group and
864        moved on to the rest of the pattern, a later failure that backtracks into
865        the group uses the captured value from the final iteration of the group
866        rather than the correct earlier one. I have fixed this in PCRE by forcing
867        any group that contains a reference to itself to be an atomic group; that
868        is, there cannot be any backtracking into it once it has completed. This is
869        similar to recursive and subroutine calls.
870    
871    
872    Version 8.00 19-Oct-09
873  ----------------------  ----------------------
874    
875  1.  The table for translating pcre_compile() error codes into POSIX error codes  1.  The table for translating pcre_compile() error codes into POSIX error codes
876      was out-of-date, and there was no check on the pcre_compile() error code      was out-of-date, and there was no check on the pcre_compile() error code
877      being within the table. This could lead to an OK return being given in      being within the table. This could lead to an OK return being given in
878      error.      error.
879    
880  2.  Changed the call to open a subject file in pcregrep from fopen(pathname,  2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
881      "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests      "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
882      in a Windows environment.      in a Windows environment.
883    
884  3.  The pcregrep --count option prints the count for each file even when it is  3.  The pcregrep --count option prints the count for each file even when it is
885      zero, as does GNU grep. However, pcregrep was also printing all files when      zero, as does GNU grep. However, pcregrep was also printing all files when
886      --files-with-matches was added. Now, when both options are given, it prints      --files-with-matches was added. Now, when both options are given, it prints
887      counts only for those files that have at least one match. (GNU grep just      counts only for those files that have at least one match. (GNU grep just
888      prints the file name in this circumstance, but including the count seems      prints the file name in this circumstance, but including the count seems
889      more useful - otherwise, why use --count?) Also ensured that the      more useful - otherwise, why use --count?) Also ensured that the
890      combination -clh just lists non-zero counts, with no names.      combination -clh just lists non-zero counts, with no names.
891    
892  4.  The long form of the pcregrep -F option was incorrectly implemented as  4.  The long form of the pcregrep -F option was incorrectly implemented as
893      --fixed_strings instead of --fixed-strings. This is an incompatible change,      --fixed_strings instead of --fixed-strings. This is an incompatible change,
894      but it seems right to fix it, and I didn't think it was worth preserving      but it seems right to fix it, and I didn't think it was worth preserving
895      the old behaviour.      the old behaviour.
896    
897  5.  The command line items --regex=pattern and --regexp=pattern were not  5.  The command line items --regex=pattern and --regexp=pattern were not
898      recognized by pcregrep, which required --regex pattern or --regexp pattern      recognized by pcregrep, which required --regex pattern or --regexp pattern
899      (with a space rather than an '='). The man page documented the '=' forms,      (with a space rather than an '='). The man page documented the '=' forms,
900      which are compatible with GNU grep; these now work.      which are compatible with GNU grep; these now work.
901    
902  6.  No libpcreposix.pc file was created for pkg-config; there was just  6.  No libpcreposix.pc file was created for pkg-config; there was just
903      libpcre.pc and libpcrecpp.pc. The omission has been rectified.      libpcre.pc and libpcrecpp.pc. The omission has been rectified.
904    
905  7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size  7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
906      when UCP support is not needed, by modifying the Python script that      when UCP support is not needed, by modifying the Python script that
907      generates it from Unicode data files. This should not matter if the module      generates it from Unicode data files. This should not matter if the module
908      is correctly used as a library, but I received one complaint about 50K of      is correctly used as a library, but I received one complaint about 50K of
909      unwanted data. My guess is that the person linked everything into his      unwanted data. My guess is that the person linked everything into his
910      program rather than using a library. Anyway, it does no harm.      program rather than using a library. Anyway, it does no harm.
911    
912  8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger  8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
913      was a minimum greater than 1 for a wide character in a possessive      was a minimum greater than 1 for a wide character in a possessive
914      repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8      repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
915      which had an unlimited repeat of a nested, fixed maximum repeat of a wide      which had an unlimited repeat of a nested, fixed maximum repeat of a wide
916      character. Chaos in the form of incorrect output or a compiling loop could      character. Chaos in the form of incorrect output or a compiling loop could
917      result.      result.
918    
919  9.  The restrictions on what a pattern can contain when partial matching is  9.  The restrictions on what a pattern can contain when partial matching is
920      requested for pcre_exec() have been removed. All patterns can now be      requested for pcre_exec() have been removed. All patterns can now be
921      partially matched by this function. In addition, if there are at least two      partially matched by this function. In addition, if there are at least two
922      slots in the offset vector, the offset of the earliest inspected character      slots in the offset vector, the offset of the earliest inspected character
923      for the match and the offset of the end of the subject are set in them when      for the match and the offset of the end of the subject are set in them when
924      PCRE_ERROR_PARTIAL is returned.      PCRE_ERROR_PARTIAL is returned.
925    
926  10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is  10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
927      synonymous with PCRE_PARTIAL, for backwards compatibility, and      synonymous with PCRE_PARTIAL, for backwards compatibility, and
928      PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,      PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
929      and may be more useful for multi-segment matching, especially with      and may be more useful for multi-segment matching.
930      pcre_exec().  
931    11. Partial matching with pcre_exec() is now more intuitive. A partial match
932  11. Partial matching with pcre_exec() is now more intuitive. A partial match      used to be given if ever the end of the subject was reached; now it is
933      used to be given if ever the end of the subject was reached; now it is      given only if matching could not proceed because another character was
934      given only if matching could not proceed because another character was      needed. This makes a difference in some odd cases such as Z(*FAIL) with the
935      needed. This makes a difference in some odd cases such as Z(*FAIL) with the      string "Z", which now yields "no match" instead of "partial match". In the
936      string "Z", which now yields "no match" instead of "partial match". In the      case of pcre_dfa_exec(), "no match" is given if every matching path for the
937      case of pcre_dfa_exec(), "no match" is given if every matching path for the      final character ended with (*FAIL).
938      final character ended with (*FAIL).  
   
939  12. Restarting a match using pcre_dfa_exec() after a partial match did not work  12. Restarting a match using pcre_dfa_exec() after a partial match did not work
940      if the pattern had a "must contain" character that was already found in the      if the pattern had a "must contain" character that was already found in the
941      earlier partial match, unless partial matching was again requested. For      earlier partial match, unless partial matching was again requested. For
942      example, with the pattern /dog.(body)?/, the "must contain" character is      example, with the pattern /dog.(body)?/, the "must contain" character is
943      "g". If the first part-match was for the string "dog", restarting with      "g". If the first part-match was for the string "dog", restarting with
944      "sbody" failed. This bug has been fixed.      "sbody" failed. This bug has been fixed.
945    
946  13. The string returned by pcre_dfa_exec() after a partial match has been  13. The string returned by pcre_dfa_exec() after a partial match has been
947      changed so that it starts at the first inspected character rather than the      changed so that it starts at the first inspected character rather than the
948      first character of the match. This makes a difference only if the pattern      first character of the match. This makes a difference only if the pattern
949      starts with a lookbehind assertion or \b or \B (\K is not supported by      starts with a lookbehind assertion or \b or \B (\K is not supported by
950      pcre_dfa_exec()). It's an incompatible change, but it makes the two      pcre_dfa_exec()). It's an incompatible change, but it makes the two
951      matching functions compatible, and I think it's the right thing to do.      matching functions compatible, and I think it's the right thing to do.
952    
953  14. Added a pcredemo man page, created automatically from the pcredemo.c file,  14. Added a pcredemo man page, created automatically from the pcredemo.c file,
954      so that the demonstration program is easily available in environments where      so that the demonstration program is easily available in environments where
955      PCRE has not been installed from source.      PCRE has not been installed from source.
956    
957  15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,  15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
958      libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared      libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
959      library.      library.
960    
961  16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.  16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
962      It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it      It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
963      is not the first non-POSIX option to be added. Clearly some people find      is not the first non-POSIX option to be added. Clearly some people find
964      these options useful.      these options useful.
965    
966  17. If a caller to the POSIX matching function regexec() passes a non-zero  17. If a caller to the POSIX matching function regexec() passes a non-zero
967      value for nmatch with a NULL value for pmatch, the value of      value for nmatch with a NULL value for pmatch, the value of
968      nmatch is forced to zero.      nmatch is forced to zero.
969    
970  18. RunGrepTest did not have a test for the availability of the -u option of  18. RunGrepTest did not have a test for the availability of the -u option of
971      the diff command, as RunTest does. It now checks in the same way as      the diff command, as RunTest does. It now checks in the same way as
972      RunTest, and also checks for the -b option.      RunTest, and also checks for the -b option.
973    
974  19. If an odd number of negated classes containing just a single character  19. If an odd number of negated classes containing just a single character
975      interposed, within parentheses, between a forward reference to a named      interposed, within parentheses, between a forward reference to a named
976      subpattern and the definition of the subpattern, compilation crashed with      subpattern and the definition of the subpattern, compilation crashed with
977      an internal error, complaining that it could not find the referenced      an internal error, complaining that it could not find the referenced
978      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
979      [The bug was that it was starting one character too far in when skipping      [The bug was that it was starting one character too far in when skipping
980      over the character class, thus treating the ] as data rather than      over the character class, thus treating the ] as data rather than
981      terminating the class. This meant it could skip too much.]      terminating the class. This meant it could skip too much.]
982    
983  20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the  20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
984      /g option in pcretest when the pattern contains \K, which makes it possible      /g option in pcretest when the pattern contains \K, which makes it possible
985      to have an empty string match not at the start, even when the pattern is      to have an empty string match not at the start, even when the pattern is
986      anchored. Updated pcretest and pcredemo to use this option.      anchored. Updated pcretest and pcredemo to use this option.
987    
988  21. If the maximum number of capturing subpatterns in a recursion was greater  21. If the maximum number of capturing subpatterns in a recursion was greater
989      than the maximum at the outer level, the higher number was returned, but      than the maximum at the outer level, the higher number was returned, but
990      with unset values at the outer level. The correct (outer level) value is      with unset values at the outer level. The correct (outer level) value is
991      now given.      now given.
992    
993  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
994      PCRE did not set those parentheses (unlike Perl). I have now found a way to      PCRE did not set those parentheses (unlike Perl). I have now found a way to
995      make it do so. The string so far is captured, making this feature      make it do so. The string so far is captured, making this feature
996      compatible with Perl.      compatible with Perl.
997    
998  23. The tests have been re-organized, adding tests 11 and 12, to make it  23. The tests have been re-organized, adding tests 11 and 12, to make it
999      possible to check the Perl 5.10 features against Perl 5.10.      possible to check the Perl 5.10 features against Perl 5.10.
1000    
1001  24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine  24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1002      pattern matches a fixed length string. PCRE did not allow this; now it      pattern matches a fixed length string. PCRE did not allow this; now it
1003      does. Neither allows recursion.      does. Neither allows recursion.
1004    
1005    25. I finally figured out how to implement a request to provide the minimum
1006        length of subject string that was needed in order to match a given pattern.
1007        (It was back references and recursion that I had previously got hung up
1008        on.) This code has now been added to pcre_study(); it finds a lower bound
1009        to the length of subject needed. It is not necessarily the greatest lower
1010        bound, but using it to avoid searching strings that are too short does give
1011        some useful speed-ups. The value is available to calling programs via
1012        pcre_fullinfo().
1013    
1014    26. While implementing 25, I discovered to my embarrassment that pcretest had
1015        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1016        study optimizations had never been tested with that matching function.
1017        Oops. What is worse, even when it was passed study data, there was a bug in
1018        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1019        were also very few tests of studied patterns with pcre_dfa_exec().
1020    
1021    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1022        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1023        on the other side of the coin, they are no longer allowed to have different
1024        names, because these cannot be distinguished in PCRE, and this has caused
1025        confusion. (This is a difference from Perl.)
1026    
1027    28. When duplicate subpattern names are present (necessarily with different
1028        numbers, as required by 27 above), and a test is made by name in a
1029        conditional pattern, either for a subpattern having been matched, or for
1030        recursion in such a pattern, all the associated numbered subpatterns are
1031        tested, and the overall condition is true if the condition is true for any
1032        one of them. This is the way Perl works, and is also more like the way
1033        testing by number works.
1034    
1035    
1036  Version 7.9 11-Apr-09  Version 7.9 11-Apr-09
1037  ---------------------  ---------------------

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