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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.01 11-Dec-09  Version 8.20
5  ----------------------  ------------
7    1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
8       a POSIX class. After further experiments with Perl, which convinced me that
9       Perl has bugs and confusions, a closing square bracket is no longer allowed
10       in a POSIX name.
12    2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no captured
13       substring, but while checking the failing first alternative, substring 1 is
14       temporarily captured. If the output vector supplied to pcre_exec() was not
15       big enough for this capture, the yield of the function was still zero
16       ("insufficient space for captured substrings"). This cannot be totally fixed
17       without adding another stack variable, which seems a lot of expense for a
18       edge case. However, I have improved the situation in cases such as
19       /(a)(b)x|abc/ matched against "abc", where the return code indicates that
20       fewer than the maximum number of slots in the ovector have been set.
22    3. Related to (2) above: when there are more back references in a pattern than
23       slots in the output vector, pcre_exec() uses temporary memory during
24       matching, and copies in the captures as far as possible afterwards. It was
25       using the entire output vector, but this conflicts with the specification
26       that only 2/3 is used for passing back captured substrings. Now it uses only
27       the first 2/3, for compatibility. This is, of course, another edge case.
29    4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
30       main code base, and can be used by building with --enable-jit. When this is
31       done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
32       runtime --no-jit option is given.
34    5. When the number of matches in a pcre_dfa_exec() run exactly filled the
35       ovector, the return from the function was zero, implying that there were
36       other matches that did not fit. The correct "exactly full" value is now
37       returned.
39    6. If a subpattern that was called recursively or as a subroutine contained
40       (*PRUNE) or any other control that caused it to give a non-standard return,
41       invalid errors such as "Error -26 (nested recursion at the same subject
42       position)" or even infinite loops could occur.
45    Version 8.13 16-Aug-2011
46    ------------------------
48    1.  The Unicode data tables have been updated to Unicode 6.0.0.
50    2.  Two minor typos in pcre_internal.h have been fixed.
52    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
53        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
54        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
56    4.  There were a number of related bugs in the code for matching backrefences
57        caselessly in UTF-8 mode when codes for the characters concerned were
58        different numbers of bytes. For example, U+023A and U+2C65 are an upper
59        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
60        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
61        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
62        2-byte code at the end of the subject (it thought there wasn't enough data
63        left).
65    5.  Comprehensive information about what went wrong is now returned by
66        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
67        as the output vector has at least 2 elements. The offset of the start of
68        the failing character and a reason code are placed in the vector.
70    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
71        now returned is for the first byte of the failing character, instead of the
72        last byte inspected. This is an incompatible change, but I hope it is small
73        enough not to be a problem. It makes the returned offset consistent with
74        pcre_exec() and pcre_dfa_exec().
76    7.  pcretest now gives a text phrase as well as the error number when
77        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
78        failure, the offset and reason code are output.
80    8.  When \R was used with a maximizing quantifier it failed to skip backwards
81        over a \r\n pair if the subsequent match failed. Instead, it just skipped
82        back over a single character (\n). This seems wrong (because it treated the
83        two characters as a single entity when going forwards), conflicts with the
84        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
85        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
86        has been changed.
88    9.  Some internal refactoring has changed the processing so that the handling
89        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
90        time (the PCRE_DOTALL option was changed this way some time ago: version
91        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
92        which was always a bit of a fudge. It also means that there is one less
93        argument for the match() function, which reduces its stack requirements
94        slightly. This change also fixes an incompatibility with Perl: the pattern
95        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
97    10. More internal refactoring has drastically reduced the number of recursive
98        calls to match() for possessively repeated groups such as (abc)++ when
99        using pcre_exec().
101    11. While implementing 10, a number of bugs in the handling of groups were
102        discovered and fixed:
104        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
105        (a|)*(?1) gave a compile-time internal error.
106        ((a|)+)+  did not notice that the outer group could match an empty string.
107        (^a|^)+   was not marked as anchored.
108        (.*a|.*)+ was not marked as matching at start or after a newline.
110    12. Yet more internal refactoring has removed another argument from the match()
111        function. Special calls to this function are now indicated by setting a
112        value in a variable in the "match data" data block.
114    13. Be more explicit in pcre_study() instead of relying on "default" for
115        opcodes that mean there is no starting character; this means that when new
116        ones are added and accidentally left out of pcre_study(), testing should
117        pick them up.
119    14. The -s option of pcretest has been documented for ages as being an old
120        synonym of -m (show memory usage). I have changed it to mean "force study
121        for every regex", that is, assume /S for every regex. This is similar to -i
122        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
123        using it. It makes it easier to run collections of tests with and without
124        study enabled, and thereby test pcre_study() more easily. All the standard
125        tests are now run with and without -s (but some patterns can be marked as
126        "never study" - see 20 below).
128    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
129        restoration of the capturing data to the outer values was not happening
130        correctly.
132    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
133        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
134        pattern had matched an empty string, and so incorrectly returned a no
135        match.
137    17. There was optimizing code for the last branch of non-capturing parentheses,
138        and also for the obeyed branch of a conditional subexpression, which used
139        tail recursion to cut down on stack usage. Unfortunately, now that there is
140        the possibility of (*THEN) occurring in these branches, tail recursion is
141        no longer possible because the return has to be checked for (*THEN). These
142        two optimizations have therefore been removed.
144    18. If a pattern containing \R was studied, it was assumed that \R always
145        matched two bytes, thus causing the minimum subject length to be
146        incorrectly computed because \R can also match just one byte.
148    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
149        was incorrectly computed.
151    20. If /S is present twice on a test pattern in pcretest input, it now
152        *disables* studying, thereby overriding the use of -s on the command line
153        (see 14 above). This is necessary for one or two tests to keep the output
154        identical in both cases.
156    21. When (*ACCEPT) was used in an assertion that matched an empty string and
157        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
159    22. When an atomic group that contained a capturing parenthesis was
160        successfully matched, but the branch in which it appeared failed, the
161        capturing was not being forgotten if a higher numbered group was later
162        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
163        group 1 to "a", when in fact it should be unset. This applied to multi-
164        branched capturing and non-capturing groups, repeated or not, and also to
165        positive assertions (capturing in negative assertions does not happen
166        in PCRE) and also to nested atomic groups.
168    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
169        subject after a captured substring, to make it easier to tell which of a
170        number of identical substrings has been captured.
172    24. The way atomic groups are processed by pcre_exec() has been changed so that
173        if they are repeated, backtracking one repetition now resets captured
174        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
175        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
176        "aaa". Previously, it would have been "a". As part of this code
177        refactoring, the way recursive calls are handled has also been changed.
179    25. If an assertion condition captured any substrings, they were not passed
180        back unless some other capturing happened later. For example, if
181        (?(?=(a))a) was matched against "a", no capturing was returned.
183    26. When studying a pattern that contained subroutine calls or assertions,
184        the code for finding the minimum length of a possible match was handling
185        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
186        group 1 called group 2 while simultaneously a separate group 2 called group
187        1). A stack overflow occurred in this case. I have fixed this by limiting
188        the recursion depth to 10.
190    27. Updated RunTest.bat in the distribution to the version supplied by Tom
191        Fortmann. This supports explicit test numbers on the command line, and has
192        argument validation and error reporting.
194    28. An instance of \X with an unlimited repeat could fail if at any point the
195        first character it looked at was a mark character.
197    29. Some minor code refactoring concerning Unicode properties and scripts
198        should reduce the stack requirement of match() slightly.
200    30. Added the '=' option to pcretest to check the setting of unused capturing
201        slots at the end of the pattern, which are documented as being -1, but are
202        not included in the return count.
204    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
205        compiled something random. Now it gives a compile-time error (as does
206        Perl).
208    32. A *MARK encountered during the processing of a positive assertion is now
209        recorded and passed back (compatible with Perl).
211    33. If --only-matching or --colour was set on a pcregrep call whose pattern
212        had alternative anchored branches, the search for a second match in a line
213        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
214        matched the line "0102" twice. The same bug affected patterns that started
215        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
216        twice.
218    34. Previously, PCRE did not allow quantification of assertions. However, Perl
219        does, and because of capturing effects, quantifying parenthesized
220        assertions may at times be useful. Quantifiers are now allowed for
221        parenthesized assertions.
223    35. A minor code tidy in pcre_compile() when checking options for \R usage.
225    36. \g was being checked for fancy things in a character class, when it should
226        just be a literal "g".
228    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
229        appearance of a nested POSIX class supersedes an apparent external class.
230        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
231        unescaped square brackets may also appear as part of class names. For
232        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
233        more like Perl. (But see 8.20/1 above.)
235    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
236        was because it thought it was \N{name}, which is not supported).
238    39. Add minix to OS list not supporting the -S option in pcretest.
240    40. PCRE tries to detect cases of infinite recursion at compile time, but it
241        cannot analyze patterns in sufficient detail to catch mutual recursions
242        such as ((?1))((?2)). There is now a runtime test that gives an error if a
243        subgroup is called recursively as a subpattern for a second time at the
244        same position in the subject string. In previous releases this might have
245        been caught by the recursion limit, or it might have run out of stack.
247    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
248        happen only once. PCRE was, however incorrectly giving a compile time error
249        "recursive call could loop indefinitely" because it cannot analyze the
250        pattern in sufficient detail. The compile time test no longer happens when
251        PCRE is compiling a conditional subpattern, but actual runaway loops are
252        now caught at runtime (see 40 above).
254    42. It seems that Perl allows any characters other than a closing parenthesis
255        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
256        has been changed to be the same.
258    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
259        as not to get warnings when autogen.sh is called. Also changed
260        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
262    44. To help people who use pcregrep to scan files containing exceedingly long
263        lines, the following changes have been made:
265        (a) The default value of the buffer size parameter has been increased from
266            8K to 20K. (The actual buffer used is three times this size.)
268        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
269            PCRE is built.
271        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
272            to be set at run time.
274        (d) Numerical values in pcregrep options can be followed by K or M, for
275            example --buffer-size=50K.
277        (e) If a line being scanned overflows pcregrep's buffer, an error is now
278            given and the return code is set to 2.
280    45. Add a pointer to the latest mark to the callout data block.
282    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
283        partial match of an empty string instead of no match. This was specific to
284        the use of ".".
286    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
287        complete match instead of a partial match. This bug was dependent on both
288        the PCRE_UTF8 and PCRE_DOTALL options being set.
290    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
291        starting byte set, because \b was not being ignored.
294    Version 8.12 15-Jan-2011
295    ------------------------
297    1.  Fixed some typos in the markup of the man pages, and wrote a script that
298        checks for such things as part of the documentation building process.
300    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
301        --match-limit and --recursion-limit options (added for 8.11). In
302        particular, this made one of the standard tests fail. (The integer value
303        went into the wrong half of a long int.)
305    3.  If the --colour option was given to pcregrep with -v (invert match), it
306        did strange things, either producing crazy output, or crashing. It should,
307        of course, ignore a request for colour when reporting lines that do not
308        match.
310    4.  Another pcregrep bug caused similar problems if --colour was specified with
311        -M (multiline) and the pattern match finished with a line ending.
313    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
314        matched in multiline mode, the following line was shown as part of the
315        match. This seems wrong, so I have changed it.
317    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
318        the check for further matches in the same line (so they could be coloured)
319        to overrun the end of the current line. If another match was found, it was
320        incorrectly shown (and then shown again when found in the next line).
322    7.  If pcregrep was compiled under Windows, there was a reference to the
323        function pcregrep_exit() before it was defined. I am assuming this was
324        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
325        reported by a user. I've moved the definition above the reference.
328    Version 8.11 10-Dec-2010
329    ------------------------
331    1.  (*THEN) was not working properly if there were untried alternatives prior
332        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
333        backtracked to try for "b" instead of moving to the next alternative branch
334        at the same level (in this case, to look for "c"). The Perl documentation
335        is clear that when (*THEN) is backtracked onto, it goes to the "next
336        alternative in the innermost enclosing group".
338    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
339        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
340        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
341        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
342        (*THEN).
344    3.  If \s appeared in a character class, it removed the VT character from
345        the class, even if it had been included by some previous item, for example
346        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
347        of \s, but is part of the POSIX "space" class.)
349    4.  A partial match never returns an empty string (because you can always
350        match an empty string at the end of the subject); however the checking for
351        an empty string was starting at the "start of match" point. This has been
352        changed to the "earliest inspected character" point, because the returned
353        data for a partial match starts at this character. This means that, for
354        example, /(?<=abc)def/ gives a partial match for the subject "abc"
355        (previously it gave "no match").
357    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
358        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
359        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
360        has an implication that the given string is incomplete (because a partial
361        match is preferred over a full match). For this reason, these items now
362        give a partial match in this situation. [Aside: previously, the one case
363        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
364        match rather than a full match, which was wrong by the old rules, but is
365        now correct.]
367    6.  There was a bug in the handling of #-introduced comments, recognized when
368        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
369        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
370        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
371        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
372        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
373        places in pcre_compile().
375    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
376        comments when looking ahead for named forward references to subpatterns,
377        the only newline sequence it recognized was NL. It now handles newlines
378        according to the set newline convention.
380    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
381        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
382        cater for a lack of strerror(). These oversights have been fixed.
384    9.  Added --match-limit and --recursion-limit to pcregrep.
386    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
388    11. When the -o option was used, pcregrep was setting a return code of 1, even
389        when matches were found, and --line-buffered was not being honoured.
391    12. Added an optional parentheses number to the -o and --only-matching options
392        of pcregrep.
394    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
395        can match an empty string. The code to do it in pcretest and pcredemo
396        needed fixing:
398        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
399            only one byte after an empty string match just before CRLF (this case
400            just got forgotten; "any" and "anycrlf" were OK).
402        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
403            mode when an empty string match preceded an ASCII character followed by
404            a non-ASCII character. (The code for advancing by one character rather
405            than one byte was nonsense.)
407        (c) The pcredemo.c sample program did not have any code at all to handle
408            the cases when CRLF is a valid newline sequence.
410    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
411        as a starting offset was within the subject string. There is now a new
412        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
413        negative or greater than the length of the string. In order to test this,
414        pcretest is extended to allow the setting of negative starting offsets.
416    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
417        starting offset points to the beginning of a UTF-8 character was
418        unnecessarily clumsy. I tidied it up.
420    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
421        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
423    17. Nobody had reported that the --include_dir option, which was added in
424        release 7.7 should have been called --include-dir (hyphen, not underscore)
425        for compatibility with GNU grep. I have changed it to --include-dir, but
426        left --include_dir as an undocumented synonym, and the same for
427        --exclude-dir, though that is not available in GNU grep, at least as of
428        release 2.5.4.
430    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
431        characters from a string of bytes) have been redefined so as not to use
432        loops, in order to improve performance in some environments. At the same
433        time, I abstracted some of the common code into auxiliary macros to save
434        repetition (this should not affect the compiled code).
436    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
437        compile-time error is now given if \c is not followed by an ASCII
438        character, that is, a byte less than 128. (In EBCDIC mode, the code is
439        different, and any byte value is allowed.)
441    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
442        START_OPTIMIZE option, which is now allowed at compile time - but just
443        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
444        to pcregrep and other applications that have no direct access to PCRE
445        options. The new /Y option in pcretest sets this option when calling
446        pcre_compile().
448    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
449        back references. Groups containing recursive back references were forced to
450        be atomic by that change, but in the case of named groups, the amount of
451        memory required was incorrectly computed, leading to "Failed: internal
452        error: code overflow". This has been fixed.
454    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
455        pcretest.c, to avoid build problems in some Borland environments.
458    Version 8.10 25-Jun-2010
459    ------------------------
461    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
462        THEN.
464    2.  (*ACCEPT) was not working when inside an atomic group.
466    3.  Inside a character class, \B is treated as a literal by default, but
467        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
468        causes the error). The code is unchanged, but I tidied the documentation.
470    4.  Inside a character class, PCRE always treated \R and \X as literals,
471        whereas Perl faults them if its -w option is set. I have changed PCRE so
472        that it faults them when PCRE_EXTRA is set.
474    5.  Added support for \N, which always matches any character other than
475        newline. (It is the same as "." when PCRE_DOTALL is not set.)
477    6.  When compiling pcregrep with newer versions of gcc which may have
478        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
479        declared with attribute warn_unused_result" were given. Just casting the
480        result to (void) does not stop the warnings; a more elaborate fudge is
481        needed. I've used a macro to implement this.
483    7.  Minor change to pcretest.c to avoid a compiler warning.
485    8.  Added four artifical Unicode properties to help with an option to make
486        \s etc use properties (see next item). The new properties are: Xan
487        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
489    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
490        use Unicode properties. (*UCP) at the start of a pattern can be used to set
491        this option. Modified pcretest to add /W to test this facility. Added
492        REG_UCP to make it available via the POSIX interface.
494    10. Added --line-buffered to pcregrep.
496    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
497        studied, and the match started with a letter with a code point greater than
498        127 whose first byte was different to the first byte of the other case of
499        the letter, the other case of this starting letter was not recognized
500        (#976).
502    12. If a pattern that was studied started with a repeated Unicode property
503        test, for example, \p{Nd}+, there was the theoretical possibility of
504        setting up an incorrect bitmap of starting bytes, but fortunately it could
505        not have actually happened in practice until change 8 above was made (it
506        added property types that matched character-matching opcodes).
508    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
509        possible starting bytes for non-anchored patterns.
511    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
512        \R, and also a number of cases that involve Unicode properties, both
513        explicit and implicit when PCRE_UCP is set.
515    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
516        input, it could crash or give wrong results if characters with values
517        greater than 0xc0 were present in the subject string. (Detail: it assumed
518        UTF-8 input when processing these items.)
520    16. Added a lot of (int) casts to avoid compiler warnings in systems where
521        size_t is 64-bit (#991).
523    17. Added a check for running out of memory when PCRE is compiled with
524        --disable-stack-for-recursion (#990).
526    18. If the last data line in a file for pcretest does not have a newline on
527        the end, a newline was missing in the output.
529    19. The default pcre_chartables.c file recognizes only ASCII characters (values
530        less than 128) in its various bitmaps. However, there is a facility for
531        generating tables according to the current locale when PCRE is compiled. It
532        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
533        characters, are recognized by isspace() and therefore were getting set in
534        these tables, and indeed these tables seem to approximate to ISO 8859. This
535        caused a problem in UTF-8 mode when pcre_study() was used to create a list
536        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
537        which of course cannot start UTF-8 characters. I have changed the code so
538        that only real ASCII characters (less than 128) and the correct starting
539        bytes for UTF-8 encodings are set for characters greater than 127 when in
540        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
541        altogether.)
543    20. Added the /T option to pcretest so as to be able to run tests with non-
544        standard character tables, thus making it possible to include the tests
545        used for 19 above in the standard set of tests.
547    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
548        reference to a subpattern the other side of a comment that contains an
549        opening parenthesis caused either an internal compiling error, or a
550        reference to the wrong subpattern.
553    Version 8.02 19-Mar-2010
554    ------------------------
556    1.  The Unicode data tables have been updated to Unicode 5.2.0.
558    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
559        configured.
561    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
562        original author of that file, following a query about its status.
564    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
565        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
567    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
568        quantifier applied to a forward-referencing subroutine call, could compile
569        incorrect code or give the error "internal error: previously-checked
570        referenced subpattern not found".
572    6.  Both MS Visual Studio and Symbian OS have problems with initializing
573        variables to point to external functions. For these systems, therefore,
574        pcre_malloc etc. are now initialized to local functions that call the
575        relevant global functions.
577    7.  There were two entries missing in the vectors called coptable and poptable
578        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
579        I've fixed the data, and added a kludgy way of testing at compile time that
580        the lengths are correct (equal to the number of opcodes).
582    8.  Following on from 7, I added a similar kludge to check the length of the
583        eint vector in pcreposix.c.
585    9.  Error texts for pcre_compile() are held as one long string to avoid too
586        much relocation at load time. To find a text, the string is searched,
587        counting zeros. There was no check for running off the end of the string,
588        which could happen if a new error number was added without updating the
589        string.
591    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
593    11. \K was not working if it appeared in an atomic group or in a group that
594        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
595        \K is "not well defined" if used in an assertion. PCRE now accepts it if
596        the assertion is positive, but not if it is negative.
598    12. Change 11 fortuitously reduced the size of the stack frame used in the
599        "match()" function of pcre_exec.c by one pointer. Forthcoming
600        implementation of support for (*MARK) will need an extra pointer on the
601        stack; I have reserved it now, so that the stack frame size does not
602        decrease.
604    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
605        item in branch that calls a recursion is a subroutine call - as in the
606        second branch in the above example - was incorrectly given the compile-
607        time error "recursive call could loop indefinitely" because pcre_compile()
608        was not correctly checking the subroutine for matching a non-empty string.
610    14. The checks for overrunning compiling workspace could trigger after an
611        overrun had occurred. This is a "should never occur" error, but it can be
612        triggered by pathological patterns such as hundreds of nested parentheses.
613        The checks now trigger 100 bytes before the end of the workspace.
615    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
618    Version 8.01 19-Jan-2010
619    ------------------------
621  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
622      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
623      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
624      subpatterns).      subpatterns). This could cause incorrect "no match" results.
626  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
627      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 26  Version 8.01 11-Dec-09 Line 640  Version 8.01 11-Dec-09
640      assertion subpattern, including such a pattern used as a condition,      assertion subpattern, including such a pattern used as a condition,
641      unpredictable results occurred, instead of the error return      unpredictable results occurred, instead of the error return
644  5.  The C++ GlobalReplace function was not working like Perl for the special  5.  The C++ GlobalReplace function was not working like Perl for the special
645      situation when an empty string is matched. It now does the fancy magic      situation when an empty string is matched. It now does the fancy magic
646      stuff that is necessary.      stuff that is necessary.
648    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
649        removed. (These were left over from very, very early versions of PCRE.)
651    7.  Some cosmetic changes to the code to make life easier when compiling it
652        as part of something else:
654        (a) Change DEBUG to PCRE_DEBUG.
656        (b) In pcre_compile(), rename the member of the "branch_chain" structure
657            called "current" as "current_branch", to prevent a collision with the
658            Linux macro when compiled as a kernel module.
660        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
661            prevent a collision with the Linux macro when compiled as a kernel
662            module.
664    8.  In pcre_compile() there are some checks for integer overflows that used to
665        cast potentially large values to (double). This has been changed to that
666        when building, a check for int64_t is made, and if it is found, it is used
667        instead, thus avoiding the use of floating point arithmetic. (There is no
668        other use of FP in PCRE.) If int64_t is not found, the fallback is to
669        double.
671    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
672        2005 (difference between two addresses compared to an unsigned value).
674    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
675        custom one, because of the following reported problem in Windows:
677          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
678              under Win32.
679          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
680              therefore missing the function definition.
681          - The compiler thus generates a "C" signature for the test function.
682          - The linker fails to find the "C" function.
683          - PCRE fails to configure if asked to do so against libbz2.
685    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
686        messages were output:
688          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
689          rerunning libtoolize, to keep the correct libtool macros in-tree.
690          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
692        I have done both of these things.
694    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
695        most of the time, it *can* run out if it is given a pattern that contains a
696        runaway infinite recursion. I updated the discussion in the pcrestack man
697        page.
699    13. Now that we have gone to the x.xx style of version numbers, the minor
700        version may start with zero. Using 08 or 09 is a bad idea because users
701        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
702        interpreted as invalid octal numbers. I've updated the previous comment in
703        configure.ac, and also added a check that gives an error if 08 or 09 are
704        used.
706    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
707        causing partial matching to fail when the end of the subject matched \W
708        in a UTF-8 pattern where \W was quantified with a minimum of 3.
710    15. There were some discrepancies between the declarations in pcre_internal.h
711        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
712        their definitions. The declarations used "const uschar *" and the
713        definitions used USPTR. Even though USPTR is normally defined as "const
714        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
715        reported that: "This difference in casting confuses some C++ compilers, for
716        example, SunCC recognizes above declarations as different functions and
717        generates broken code for hbpcre." I have changed the declarations to use
718        USPTR.
720    16. GNU libtool is named differently on some systems. The autogen.sh script now
721        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
722        (FreeBSD).
724    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
725        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
726        comment: "Figure out how to create a longlong from a string: strtoll and
727        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
728        instance, but it only takes 2 args instead of 3!"
730    18. A subtle bug concerned with back references has been fixed by a change of
731        specification, with a corresponding code fix. A pattern such as
732        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
733        refers, was giving matches when it shouldn't. For example, xa=xaaa would
734        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
735        same bug. Such groups have to be quantified to be useful, or contained
736        inside another quantified group. (If there's no repetition, the reference
737        can never match.) The problem arises because, having left the group and
738        moved on to the rest of the pattern, a later failure that backtracks into
739        the group uses the captured value from the final iteration of the group
740        rather than the correct earlier one. I have fixed this in PCRE by forcing
741        any group that contains a reference to itself to be an atomic group; that
742        is, there cannot be any backtracking into it once it has completed. This is
743        similar to recursive and subroutine calls.
746  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09

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