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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.01 11-Dec-09  Version 8.20 12-Sep-2011
5  ----------------------  ------------------------
6    
7    1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
8       a POSIX class. After further experiments with Perl, which convinced me that
9       Perl has bugs and confusions, a closing square bracket is no longer allowed
10       in a POSIX name. This bug also affected patterns with classes that started
11       with full stops.
12    
13    2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no captured
14       substring, but while checking the failing first alternative, substring 1 is
15       temporarily captured. If the output vector supplied to pcre_exec() was not
16       big enough for this capture, the yield of the function was still zero
17       ("insufficient space for captured substrings"). This cannot be totally fixed
18       without adding another stack variable, which seems a lot of expense for a
19       edge case. However, I have improved the situation in cases such as
20       /(a)(b)x|abc/ matched against "abc", where the return code indicates that
21       fewer than the maximum number of slots in the ovector have been set.
22    
23    3. Related to (2) above: when there are more back references in a pattern than
24       slots in the output vector, pcre_exec() uses temporary memory during
25       matching, and copies in the captures as far as possible afterwards. It was
26       using the entire output vector, but this conflicts with the specification
27       that only 2/3 is used for passing back captured substrings. Now it uses only
28       the first 2/3, for compatibility. This is, of course, another edge case.
29    
30    4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
31       main code base, and can be used by building with --enable-jit. When this is
32       done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
33       runtime --no-jit option is given.
34    
35    5. When the number of matches in a pcre_dfa_exec() run exactly filled the
36       ovector, the return from the function was zero, implying that there were
37       other matches that did not fit. The correct "exactly full" value is now
38       returned.
39    
40    6. If a subpattern that was called recursively or as a subroutine contained
41       (*PRUNE) or any other control that caused it to give a non-standard return,
42       invalid errors such as "Error -26 (nested recursion at the same subject
43       position)" or even infinite loops could occur.
44    
45    7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
46       computing the minimum length on reaching *ACCEPT, and so ended up with the
47       wrong value of 1 rather than 0. Further investigation indicates that
48       computing a minimum subject length in the presence of *ACCEPT is difficult
49       (think back references, subroutine calls), and so I have changed the code so
50       that no minimum is registered for a pattern that contains *ACCEPT.
51    
52    8. If (*THEN) was present in the first (true) branch of a conditional group,
53       it was not handled as intended.
54    
55    
56    Version 8.13 16-Aug-2011
57    ------------------------
58    
59    1.  The Unicode data tables have been updated to Unicode 6.0.0.
60    
61    2.  Two minor typos in pcre_internal.h have been fixed.
62    
63    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
64        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
65        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
66    
67    4.  There were a number of related bugs in the code for matching backrefences
68        caselessly in UTF-8 mode when codes for the characters concerned were
69        different numbers of bytes. For example, U+023A and U+2C65 are an upper
70        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
71        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
72        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
73        2-byte code at the end of the subject (it thought there wasn't enough data
74        left).
75    
76    5.  Comprehensive information about what went wrong is now returned by
77        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
78        as the output vector has at least 2 elements. The offset of the start of
79        the failing character and a reason code are placed in the vector.
80    
81    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
82        now returned is for the first byte of the failing character, instead of the
83        last byte inspected. This is an incompatible change, but I hope it is small
84        enough not to be a problem. It makes the returned offset consistent with
85        pcre_exec() and pcre_dfa_exec().
86    
87    7.  pcretest now gives a text phrase as well as the error number when
88        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
89        failure, the offset and reason code are output.
90    
91    8.  When \R was used with a maximizing quantifier it failed to skip backwards
92        over a \r\n pair if the subsequent match failed. Instead, it just skipped
93        back over a single character (\n). This seems wrong (because it treated the
94        two characters as a single entity when going forwards), conflicts with the
95        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
96        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
97        has been changed.
98    
99    9.  Some internal refactoring has changed the processing so that the handling
100        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
101        time (the PCRE_DOTALL option was changed this way some time ago: version
102        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
103        which was always a bit of a fudge. It also means that there is one less
104        argument for the match() function, which reduces its stack requirements
105        slightly. This change also fixes an incompatibility with Perl: the pattern
106        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
107    
108    10. More internal refactoring has drastically reduced the number of recursive
109        calls to match() for possessively repeated groups such as (abc)++ when
110        using pcre_exec().
111    
112    11. While implementing 10, a number of bugs in the handling of groups were
113        discovered and fixed:
114    
115        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
116        (a|)*(?1) gave a compile-time internal error.
117        ((a|)+)+  did not notice that the outer group could match an empty string.
118        (^a|^)+   was not marked as anchored.
119        (.*a|.*)+ was not marked as matching at start or after a newline.
120    
121    12. Yet more internal refactoring has removed another argument from the match()
122        function. Special calls to this function are now indicated by setting a
123        value in a variable in the "match data" data block.
124    
125    13. Be more explicit in pcre_study() instead of relying on "default" for
126        opcodes that mean there is no starting character; this means that when new
127        ones are added and accidentally left out of pcre_study(), testing should
128        pick them up.
129    
130    14. The -s option of pcretest has been documented for ages as being an old
131        synonym of -m (show memory usage). I have changed it to mean "force study
132        for every regex", that is, assume /S for every regex. This is similar to -i
133        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
134        using it. It makes it easier to run collections of tests with and without
135        study enabled, and thereby test pcre_study() more easily. All the standard
136        tests are now run with and without -s (but some patterns can be marked as
137        "never study" - see 20 below).
138    
139    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
140        restoration of the capturing data to the outer values was not happening
141        correctly.
142    
143    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
144        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
145        pattern had matched an empty string, and so incorrectly returned a no
146        match.
147    
148    17. There was optimizing code for the last branch of non-capturing parentheses,
149        and also for the obeyed branch of a conditional subexpression, which used
150        tail recursion to cut down on stack usage. Unfortunately, now that there is
151        the possibility of (*THEN) occurring in these branches, tail recursion is
152        no longer possible because the return has to be checked for (*THEN). These
153        two optimizations have therefore been removed.
154    
155    18. If a pattern containing \R was studied, it was assumed that \R always
156        matched two bytes, thus causing the minimum subject length to be
157        incorrectly computed because \R can also match just one byte.
158    
159    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
160        was incorrectly computed.
161    
162    20. If /S is present twice on a test pattern in pcretest input, it now
163        *disables* studying, thereby overriding the use of -s on the command line
164        (see 14 above). This is necessary for one or two tests to keep the output
165        identical in both cases.
166    
167    21. When (*ACCEPT) was used in an assertion that matched an empty string and
168        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
169    
170    22. When an atomic group that contained a capturing parenthesis was
171        successfully matched, but the branch in which it appeared failed, the
172        capturing was not being forgotten if a higher numbered group was later
173        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
174        group 1 to "a", when in fact it should be unset. This applied to multi-
175        branched capturing and non-capturing groups, repeated or not, and also to
176        positive assertions (capturing in negative assertions does not happen
177        in PCRE) and also to nested atomic groups.
178    
179    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
180        subject after a captured substring, to make it easier to tell which of a
181        number of identical substrings has been captured.
182    
183    24. The way atomic groups are processed by pcre_exec() has been changed so that
184        if they are repeated, backtracking one repetition now resets captured
185        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
186        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
187        "aaa". Previously, it would have been "a". As part of this code
188        refactoring, the way recursive calls are handled has also been changed.
189    
190    25. If an assertion condition captured any substrings, they were not passed
191        back unless some other capturing happened later. For example, if
192        (?(?=(a))a) was matched against "a", no capturing was returned.
193    
194    26. When studying a pattern that contained subroutine calls or assertions,
195        the code for finding the minimum length of a possible match was handling
196        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
197        group 1 called group 2 while simultaneously a separate group 2 called group
198        1). A stack overflow occurred in this case. I have fixed this by limiting
199        the recursion depth to 10.
200    
201    27. Updated RunTest.bat in the distribution to the version supplied by Tom
202        Fortmann. This supports explicit test numbers on the command line, and has
203        argument validation and error reporting.
204    
205    28. An instance of \X with an unlimited repeat could fail if at any point the
206        first character it looked at was a mark character.
207    
208    29. Some minor code refactoring concerning Unicode properties and scripts
209        should reduce the stack requirement of match() slightly.
210    
211    30. Added the '=' option to pcretest to check the setting of unused capturing
212        slots at the end of the pattern, which are documented as being -1, but are
213        not included in the return count.
214    
215    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
216        compiled something random. Now it gives a compile-time error (as does
217        Perl).
218    
219    32. A *MARK encountered during the processing of a positive assertion is now
220        recorded and passed back (compatible with Perl).
221    
222    33. If --only-matching or --colour was set on a pcregrep call whose pattern
223        had alternative anchored branches, the search for a second match in a line
224        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
225        matched the line "0102" twice. The same bug affected patterns that started
226        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
227        twice.
228    
229    34. Previously, PCRE did not allow quantification of assertions. However, Perl
230        does, and because of capturing effects, quantifying parenthesized
231        assertions may at times be useful. Quantifiers are now allowed for
232        parenthesized assertions.
233    
234    35. A minor code tidy in pcre_compile() when checking options for \R usage.
235    
236    36. \g was being checked for fancy things in a character class, when it should
237        just be a literal "g".
238    
239    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
240        appearance of a nested POSIX class supersedes an apparent external class.
241        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
242        unescaped square brackets may also appear as part of class names. For
243        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
244        more like Perl. (But see 8.20/1 above.)
245    
246    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
247        was because it thought it was \N{name}, which is not supported).
248    
249    39. Add minix to OS list not supporting the -S option in pcretest.
250    
251    40. PCRE tries to detect cases of infinite recursion at compile time, but it
252        cannot analyze patterns in sufficient detail to catch mutual recursions
253        such as ((?1))((?2)). There is now a runtime test that gives an error if a
254        subgroup is called recursively as a subpattern for a second time at the
255        same position in the subject string. In previous releases this might have
256        been caught by the recursion limit, or it might have run out of stack.
257    
258    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
259        happen only once. PCRE was, however incorrectly giving a compile time error
260        "recursive call could loop indefinitely" because it cannot analyze the
261        pattern in sufficient detail. The compile time test no longer happens when
262        PCRE is compiling a conditional subpattern, but actual runaway loops are
263        now caught at runtime (see 40 above).
264    
265    42. It seems that Perl allows any characters other than a closing parenthesis
266        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
267        has been changed to be the same.
268    
269    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
270        as not to get warnings when autogen.sh is called. Also changed
271        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
272    
273    44. To help people who use pcregrep to scan files containing exceedingly long
274        lines, the following changes have been made:
275    
276        (a) The default value of the buffer size parameter has been increased from
277            8K to 20K. (The actual buffer used is three times this size.)
278    
279        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
280            PCRE is built.
281    
282        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
283            to be set at run time.
284    
285        (d) Numerical values in pcregrep options can be followed by K or M, for
286            example --buffer-size=50K.
287    
288        (e) If a line being scanned overflows pcregrep's buffer, an error is now
289            given and the return code is set to 2.
290    
291    45. Add a pointer to the latest mark to the callout data block.
292    
293    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
294        partial match of an empty string instead of no match. This was specific to
295        the use of ".".
296    
297    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
298        complete match instead of a partial match. This bug was dependent on both
299        the PCRE_UTF8 and PCRE_DOTALL options being set.
300    
301    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
302        starting byte set, because \b was not being ignored.
303    
304    
305    Version 8.12 15-Jan-2011
306    ------------------------
307    
308    1.  Fixed some typos in the markup of the man pages, and wrote a script that
309        checks for such things as part of the documentation building process.
310    
311    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
312        --match-limit and --recursion-limit options (added for 8.11). In
313        particular, this made one of the standard tests fail. (The integer value
314        went into the wrong half of a long int.)
315    
316    3.  If the --colour option was given to pcregrep with -v (invert match), it
317        did strange things, either producing crazy output, or crashing. It should,
318        of course, ignore a request for colour when reporting lines that do not
319        match.
320    
321    4.  Another pcregrep bug caused similar problems if --colour was specified with
322        -M (multiline) and the pattern match finished with a line ending.
323    
324    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
325        matched in multiline mode, the following line was shown as part of the
326        match. This seems wrong, so I have changed it.
327    
328    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
329        the check for further matches in the same line (so they could be coloured)
330        to overrun the end of the current line. If another match was found, it was
331        incorrectly shown (and then shown again when found in the next line).
332    
333    7.  If pcregrep was compiled under Windows, there was a reference to the
334        function pcregrep_exit() before it was defined. I am assuming this was
335        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
336        reported by a user. I've moved the definition above the reference.
337    
338    
339    Version 8.11 10-Dec-2010
340    ------------------------
341    
342    1.  (*THEN) was not working properly if there were untried alternatives prior
343        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
344        backtracked to try for "b" instead of moving to the next alternative branch
345        at the same level (in this case, to look for "c"). The Perl documentation
346        is clear that when (*THEN) is backtracked onto, it goes to the "next
347        alternative in the innermost enclosing group".
348    
349    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
350        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
351        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
352        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
353        (*THEN).
354    
355    3.  If \s appeared in a character class, it removed the VT character from
356        the class, even if it had been included by some previous item, for example
357        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
358        of \s, but is part of the POSIX "space" class.)
359    
360    4.  A partial match never returns an empty string (because you can always
361        match an empty string at the end of the subject); however the checking for
362        an empty string was starting at the "start of match" point. This has been
363        changed to the "earliest inspected character" point, because the returned
364        data for a partial match starts at this character. This means that, for
365        example, /(?<=abc)def/ gives a partial match for the subject "abc"
366        (previously it gave "no match").
367    
368    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
369        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
370        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
371        has an implication that the given string is incomplete (because a partial
372        match is preferred over a full match). For this reason, these items now
373        give a partial match in this situation. [Aside: previously, the one case
374        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
375        match rather than a full match, which was wrong by the old rules, but is
376        now correct.]
377    
378    6.  There was a bug in the handling of #-introduced comments, recognized when
379        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
380        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
381        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
382        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
383        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
384        places in pcre_compile().
385    
386    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
387        comments when looking ahead for named forward references to subpatterns,
388        the only newline sequence it recognized was NL. It now handles newlines
389        according to the set newline convention.
390    
391    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
392        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
393        cater for a lack of strerror(). These oversights have been fixed.
394    
395    9.  Added --match-limit and --recursion-limit to pcregrep.
396    
397    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
398    
399    11. When the -o option was used, pcregrep was setting a return code of 1, even
400        when matches were found, and --line-buffered was not being honoured.
401    
402    12. Added an optional parentheses number to the -o and --only-matching options
403        of pcregrep.
404    
405    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
406        can match an empty string. The code to do it in pcretest and pcredemo
407        needed fixing:
408    
409        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
410            only one byte after an empty string match just before CRLF (this case
411            just got forgotten; "any" and "anycrlf" were OK).
412    
413        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
414            mode when an empty string match preceded an ASCII character followed by
415            a non-ASCII character. (The code for advancing by one character rather
416            than one byte was nonsense.)
417    
418        (c) The pcredemo.c sample program did not have any code at all to handle
419            the cases when CRLF is a valid newline sequence.
420    
421    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
422        as a starting offset was within the subject string. There is now a new
423        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
424        negative or greater than the length of the string. In order to test this,
425        pcretest is extended to allow the setting of negative starting offsets.
426    
427    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
428        starting offset points to the beginning of a UTF-8 character was
429        unnecessarily clumsy. I tidied it up.
430    
431    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
432        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
433    
434    17. Nobody had reported that the --include_dir option, which was added in
435        release 7.7 should have been called --include-dir (hyphen, not underscore)
436        for compatibility with GNU grep. I have changed it to --include-dir, but
437        left --include_dir as an undocumented synonym, and the same for
438        --exclude-dir, though that is not available in GNU grep, at least as of
439        release 2.5.4.
440    
441    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
442        characters from a string of bytes) have been redefined so as not to use
443        loops, in order to improve performance in some environments. At the same
444        time, I abstracted some of the common code into auxiliary macros to save
445        repetition (this should not affect the compiled code).
446    
447    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
448        compile-time error is now given if \c is not followed by an ASCII
449        character, that is, a byte less than 128. (In EBCDIC mode, the code is
450        different, and any byte value is allowed.)
451    
452    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
453        START_OPTIMIZE option, which is now allowed at compile time - but just
454        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
455        to pcregrep and other applications that have no direct access to PCRE
456        options. The new /Y option in pcretest sets this option when calling
457        pcre_compile().
458    
459    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
460        back references. Groups containing recursive back references were forced to
461        be atomic by that change, but in the case of named groups, the amount of
462        memory required was incorrectly computed, leading to "Failed: internal
463        error: code overflow". This has been fixed.
464    
465    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
466        pcretest.c, to avoid build problems in some Borland environments.
467    
468    
469    Version 8.10 25-Jun-2010
470    ------------------------
471    
472    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
473        THEN.
474    
475    2.  (*ACCEPT) was not working when inside an atomic group.
476    
477    3.  Inside a character class, \B is treated as a literal by default, but
478        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
479        causes the error). The code is unchanged, but I tidied the documentation.
480    
481    4.  Inside a character class, PCRE always treated \R and \X as literals,
482        whereas Perl faults them if its -w option is set. I have changed PCRE so
483        that it faults them when PCRE_EXTRA is set.
484    
485    5.  Added support for \N, which always matches any character other than
486        newline. (It is the same as "." when PCRE_DOTALL is not set.)
487    
488    6.  When compiling pcregrep with newer versions of gcc which may have
489        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
490        declared with attribute warn_unused_result" were given. Just casting the
491        result to (void) does not stop the warnings; a more elaborate fudge is
492        needed. I've used a macro to implement this.
493    
494    7.  Minor change to pcretest.c to avoid a compiler warning.
495    
496    8.  Added four artifical Unicode properties to help with an option to make
497        \s etc use properties (see next item). The new properties are: Xan
498        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
499    
500    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
501        use Unicode properties. (*UCP) at the start of a pattern can be used to set
502        this option. Modified pcretest to add /W to test this facility. Added
503        REG_UCP to make it available via the POSIX interface.
504    
505    10. Added --line-buffered to pcregrep.
506    
507    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
508        studied, and the match started with a letter with a code point greater than
509        127 whose first byte was different to the first byte of the other case of
510        the letter, the other case of this starting letter was not recognized
511        (#976).
512    
513    12. If a pattern that was studied started with a repeated Unicode property
514        test, for example, \p{Nd}+, there was the theoretical possibility of
515        setting up an incorrect bitmap of starting bytes, but fortunately it could
516        not have actually happened in practice until change 8 above was made (it
517        added property types that matched character-matching opcodes).
518    
519    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
520        possible starting bytes for non-anchored patterns.
521    
522    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
523        \R, and also a number of cases that involve Unicode properties, both
524        explicit and implicit when PCRE_UCP is set.
525    
526    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
527        input, it could crash or give wrong results if characters with values
528        greater than 0xc0 were present in the subject string. (Detail: it assumed
529        UTF-8 input when processing these items.)
530    
531    16. Added a lot of (int) casts to avoid compiler warnings in systems where
532        size_t is 64-bit (#991).
533    
534    17. Added a check for running out of memory when PCRE is compiled with
535        --disable-stack-for-recursion (#990).
536    
537    18. If the last data line in a file for pcretest does not have a newline on
538        the end, a newline was missing in the output.
539    
540    19. The default pcre_chartables.c file recognizes only ASCII characters (values
541        less than 128) in its various bitmaps. However, there is a facility for
542        generating tables according to the current locale when PCRE is compiled. It
543        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
544        characters, are recognized by isspace() and therefore were getting set in
545        these tables, and indeed these tables seem to approximate to ISO 8859. This
546        caused a problem in UTF-8 mode when pcre_study() was used to create a list
547        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
548        which of course cannot start UTF-8 characters. I have changed the code so
549        that only real ASCII characters (less than 128) and the correct starting
550        bytes for UTF-8 encodings are set for characters greater than 127 when in
551        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
552        altogether.)
553    
554    20. Added the /T option to pcretest so as to be able to run tests with non-
555        standard character tables, thus making it possible to include the tests
556        used for 19 above in the standard set of tests.
557    
558    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
559        reference to a subpattern the other side of a comment that contains an
560        opening parenthesis caused either an internal compiling error, or a
561        reference to the wrong subpattern.
562    
563    
564    Version 8.02 19-Mar-2010
565    ------------------------
566    
567    1.  The Unicode data tables have been updated to Unicode 5.2.0.
568    
569    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
570        configured.
571    
572    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
573        original author of that file, following a query about its status.
574    
575    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
576        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
577    
578    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
579        quantifier applied to a forward-referencing subroutine call, could compile
580        incorrect code or give the error "internal error: previously-checked
581        referenced subpattern not found".
582    
583    6.  Both MS Visual Studio and Symbian OS have problems with initializing
584        variables to point to external functions. For these systems, therefore,
585        pcre_malloc etc. are now initialized to local functions that call the
586        relevant global functions.
587    
588    7.  There were two entries missing in the vectors called coptable and poptable
589        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
590        I've fixed the data, and added a kludgy way of testing at compile time that
591        the lengths are correct (equal to the number of opcodes).
592    
593    8.  Following on from 7, I added a similar kludge to check the length of the
594        eint vector in pcreposix.c.
595    
596    9.  Error texts for pcre_compile() are held as one long string to avoid too
597        much relocation at load time. To find a text, the string is searched,
598        counting zeros. There was no check for running off the end of the string,
599        which could happen if a new error number was added without updating the
600        string.
601    
602    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
603    
604    11. \K was not working if it appeared in an atomic group or in a group that
605        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
606        \K is "not well defined" if used in an assertion. PCRE now accepts it if
607        the assertion is positive, but not if it is negative.
608    
609    12. Change 11 fortuitously reduced the size of the stack frame used in the
610        "match()" function of pcre_exec.c by one pointer. Forthcoming
611        implementation of support for (*MARK) will need an extra pointer on the
612        stack; I have reserved it now, so that the stack frame size does not
613        decrease.
614    
615    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
616        item in branch that calls a recursion is a subroutine call - as in the
617        second branch in the above example - was incorrectly given the compile-
618        time error "recursive call could loop indefinitely" because pcre_compile()
619        was not correctly checking the subroutine for matching a non-empty string.
620    
621    14. The checks for overrunning compiling workspace could trigger after an
622        overrun had occurred. This is a "should never occur" error, but it can be
623        triggered by pathological patterns such as hundreds of nested parentheses.
624        The checks now trigger 100 bytes before the end of the workspace.
625    
626    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
627    
628    
629    Version 8.01 19-Jan-2010
630    ------------------------
631    
632  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
633      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
634      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
635      subpatterns).      subpatterns). This could cause incorrect "no match" results.
636    
637  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
638      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 686  Version 8.01 11-Dec-09
686      custom one, because of the following reported problem in Windows:      custom one, because of the following reported problem in Windows:
687    
688        - libbz2 uses the Pascal calling convention (WINAPI) for the functions        - libbz2 uses the Pascal calling convention (WINAPI) for the functions
689          under Win32.            under Win32.
690        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",        - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
691          therefore missing the function definition.            therefore missing the function definition.
692        - The compiler thus generates a "C" signature for the test function.        - The compiler thus generates a "C" signature for the test function.
693        - The linker fails to find the "C" function.        - The linker fails to find the "C" function.
694        - PCRE fails to configure if asked to do so against libbz2.        - PCRE fails to configure if asked to do so against libbz2.
695    
696  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
697      messages were output:      messages were output:
698    
699        Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and        Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
700        rerunning libtoolize, to keep the correct libtool macros in-tree.        rerunning libtoolize, to keep the correct libtool macros in-tree.
701        Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.        Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
702    
703      I have done both of these things.      I have done both of these things.
704    
705  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()
706      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
707      runaway infinite recursion. I updated the discussion in the pcrestack man      runaway infinite recursion. I updated the discussion in the pcrestack man
708      page.      page.
709    
710  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
711      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
712      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
713      interpreted as invalid octal numbers. I've updated the previous comment in      interpreted as invalid octal numbers. I've updated the previous comment in
714      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
715      used.      used.
716    
717  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,
718      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
719      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.
720    
721  15. There were some discrepancies between the declarations in pcre_internal.h  15. There were some discrepancies between the declarations in pcre_internal.h
722      of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and      of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
723      their definitions. The declarations used "const uschar *" and the      their definitions. The declarations used "const uschar *" and the
724      definitions used USPTR. Even though USPTR is normally defined as "const      definitions used USPTR. Even though USPTR is normally defined as "const
725      unsigned char *" (and uschar is typedeffed as "unsigned char"), it was      unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
726      reported that: "This difference in casting confuses some C++ compilers, for      reported that: "This difference in casting confuses some C++ compilers, for
727      example, SunCC recognizes above declarations as different functions and      example, SunCC recognizes above declarations as different functions and
728      generates broken code for hbpcre." I have changed the declarations to use      generates broken code for hbpcre." I have changed the declarations to use
729      USPTR.      USPTR.
730    
731    16. GNU libtool is named differently on some systems. The autogen.sh script now
732        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
733        (FreeBSD).
734    
735    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
736        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
737        comment: "Figure out how to create a longlong from a string: strtoll and
738        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
739        instance, but it only takes 2 args instead of 3!"
740    
741    18. A subtle bug concerned with back references has been fixed by a change of
742        specification, with a corresponding code fix. A pattern such as
743        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
744        refers, was giving matches when it shouldn't. For example, xa=xaaa would
745        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
746        same bug. Such groups have to be quantified to be useful, or contained
747        inside another quantified group. (If there's no repetition, the reference
748        can never match.) The problem arises because, having left the group and
749        moved on to the rest of the pattern, a later failure that backtracks into
750        the group uses the captured value from the final iteration of the group
751        rather than the correct earlier one. I have fixed this in PCRE by forcing
752        any group that contains a reference to itself to be an atomic group; that
753        is, there cannot be any backtracking into it once it has completed. This is
754        similar to recursive and subroutine calls.
755    
756    
757  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09

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