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

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