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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.3 20-Aug-07  Version 8.20
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.
11    
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.
21    
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.
28    
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.
31    
32    5. When the number of matches in a pcre_dfa_exec() run exactly filled the
33       ovector, the return from the function was zero, implying that there were
34       other matches that did not fit. The correct "exactly full" value is now
35       returned.
36    
37    6. If a subpattern that was called recursively or as a subroutine contained
38       (*PRUNE) or any other control that caused it to give a non-standard return,
39       invalid errors such as "Error -26 (nested recursion at the same subject
40       position)" or even infinite loops could occur.
41    
42    
43    Version 8.13 16-Aug-2011
44    ------------------------
45    
46    1.  The Unicode data tables have been updated to Unicode 6.0.0.
47    
48    2.  Two minor typos in pcre_internal.h have been fixed.
49    
50    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
51        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
52        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
53    
54    4.  There were a number of related bugs in the code for matching backrefences
55        caselessly in UTF-8 mode when codes for the characters concerned were
56        different numbers of bytes. For example, U+023A and U+2C65 are an upper
57        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
58        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
59        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
60        2-byte code at the end of the subject (it thought there wasn't enough data
61        left).
62    
63    5.  Comprehensive information about what went wrong is now returned by
64        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
65        as the output vector has at least 2 elements. The offset of the start of
66        the failing character and a reason code are placed in the vector.
67    
68    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
69        now returned is for the first byte of the failing character, instead of the
70        last byte inspected. This is an incompatible change, but I hope it is small
71        enough not to be a problem. It makes the returned offset consistent with
72        pcre_exec() and pcre_dfa_exec().
73    
74    7.  pcretest now gives a text phrase as well as the error number when
75        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
76        failure, the offset and reason code are output.
77    
78    8.  When \R was used with a maximizing quantifier it failed to skip backwards
79        over a \r\n pair if the subsequent match failed. Instead, it just skipped
80        back over a single character (\n). This seems wrong (because it treated the
81        two characters as a single entity when going forwards), conflicts with the
82        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
83        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
84        has been changed.
85    
86    9.  Some internal refactoring has changed the processing so that the handling
87        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
88        time (the PCRE_DOTALL option was changed this way some time ago: version
89        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
90        which was always a bit of a fudge. It also means that there is one less
91        argument for the match() function, which reduces its stack requirements
92        slightly. This change also fixes an incompatibility with Perl: the pattern
93        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
94    
95    10. More internal refactoring has drastically reduced the number of recursive
96        calls to match() for possessively repeated groups such as (abc)++ when
97        using pcre_exec().
98    
99    11. While implementing 10, a number of bugs in the handling of groups were
100        discovered and fixed:
101    
102        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
103        (a|)*(?1) gave a compile-time internal error.
104        ((a|)+)+  did not notice that the outer group could match an empty string.
105        (^a|^)+   was not marked as anchored.
106        (.*a|.*)+ was not marked as matching at start or after a newline.
107    
108    12. Yet more internal refactoring has removed another argument from the match()
109        function. Special calls to this function are now indicated by setting a
110        value in a variable in the "match data" data block.
111    
112    13. Be more explicit in pcre_study() instead of relying on "default" for
113        opcodes that mean there is no starting character; this means that when new
114        ones are added and accidentally left out of pcre_study(), testing should
115        pick them up.
116    
117    14. The -s option of pcretest has been documented for ages as being an old
118        synonym of -m (show memory usage). I have changed it to mean "force study
119        for every regex", that is, assume /S for every regex. This is similar to -i
120        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
121        using it. It makes it easier to run collections of tests with and without
122        study enabled, and thereby test pcre_study() more easily. All the standard
123        tests are now run with and without -s (but some patterns can be marked as
124        "never study" - see 20 below).
125    
126    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
127        restoration of the capturing data to the outer values was not happening
128        correctly.
129    
130    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
131        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
132        pattern had matched an empty string, and so incorrectly returned a no
133        match.
134    
135    17. There was optimizing code for the last branch of non-capturing parentheses,
136        and also for the obeyed branch of a conditional subexpression, which used
137        tail recursion to cut down on stack usage. Unfortunately, now that there is
138        the possibility of (*THEN) occurring in these branches, tail recursion is
139        no longer possible because the return has to be checked for (*THEN). These
140        two optimizations have therefore been removed.
141    
142    18. If a pattern containing \R was studied, it was assumed that \R always
143        matched two bytes, thus causing the minimum subject length to be
144        incorrectly computed because \R can also match just one byte.
145    
146    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
147        was incorrectly computed.
148    
149    20. If /S is present twice on a test pattern in pcretest input, it now
150        *disables* studying, thereby overriding the use of -s on the command line
151        (see 14 above). This is necessary for one or two tests to keep the output
152        identical in both cases.
153    
154    21. When (*ACCEPT) was used in an assertion that matched an empty string and
155        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
156    
157    22. When an atomic group that contained a capturing parenthesis was
158        successfully matched, but the branch in which it appeared failed, the
159        capturing was not being forgotten if a higher numbered group was later
160        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
161        group 1 to "a", when in fact it should be unset. This applied to multi-
162        branched capturing and non-capturing groups, repeated or not, and also to
163        positive assertions (capturing in negative assertions does not happen
164        in PCRE) and also to nested atomic groups.
165    
166    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
167        subject after a captured substring, to make it easier to tell which of a
168        number of identical substrings has been captured.
169    
170    24. The way atomic groups are processed by pcre_exec() has been changed so that
171        if they are repeated, backtracking one repetition now resets captured
172        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
173        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
174        "aaa". Previously, it would have been "a". As part of this code
175        refactoring, the way recursive calls are handled has also been changed.
176    
177    25. If an assertion condition captured any substrings, they were not passed
178        back unless some other capturing happened later. For example, if
179        (?(?=(a))a) was matched against "a", no capturing was returned.
180    
181    26. When studying a pattern that contained subroutine calls or assertions,
182        the code for finding the minimum length of a possible match was handling
183        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
184        group 1 called group 2 while simultaneously a separate group 2 called group
185        1). A stack overflow occurred in this case. I have fixed this by limiting
186        the recursion depth to 10.
187    
188    27. Updated RunTest.bat in the distribution to the version supplied by Tom
189        Fortmann. This supports explicit test numbers on the command line, and has
190        argument validation and error reporting.
191    
192    28. An instance of \X with an unlimited repeat could fail if at any point the
193        first character it looked at was a mark character.
194    
195    29. Some minor code refactoring concerning Unicode properties and scripts
196        should reduce the stack requirement of match() slightly.
197    
198    30. Added the '=' option to pcretest to check the setting of unused capturing
199        slots at the end of the pattern, which are documented as being -1, but are
200        not included in the return count.
201    
202    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
203        compiled something random. Now it gives a compile-time error (as does
204        Perl).
205    
206    32. A *MARK encountered during the processing of a positive assertion is now
207        recorded and passed back (compatible with Perl).
208    
209    33. If --only-matching or --colour was set on a pcregrep call whose pattern
210        had alternative anchored branches, the search for a second match in a line
211        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
212        matched the line "0102" twice. The same bug affected patterns that started
213        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
214        twice.
215    
216    34. Previously, PCRE did not allow quantification of assertions. However, Perl
217        does, and because of capturing effects, quantifying parenthesized
218        assertions may at times be useful. Quantifiers are now allowed for
219        parenthesized assertions.
220    
221    35. A minor code tidy in pcre_compile() when checking options for \R usage.
222    
223    36. \g was being checked for fancy things in a character class, when it should
224        just be a literal "g".
225    
226    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
227        appearance of a nested POSIX class supersedes an apparent external class.
228        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
229        unescaped square brackets may also appear as part of class names. For
230        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
231        more like Perl. (But see 8.20/1 above.)
232    
233    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
234        was because it thought it was \N{name}, which is not supported).
235    
236    39. Add minix to OS list not supporting the -S option in pcretest.
237    
238    40. PCRE tries to detect cases of infinite recursion at compile time, but it
239        cannot analyze patterns in sufficient detail to catch mutual recursions
240        such as ((?1))((?2)). There is now a runtime test that gives an error if a
241        subgroup is called recursively as a subpattern for a second time at the
242        same position in the subject string. In previous releases this might have
243        been caught by the recursion limit, or it might have run out of stack.
244    
245    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
246        happen only once. PCRE was, however incorrectly giving a compile time error
247        "recursive call could loop indefinitely" because it cannot analyze the
248        pattern in sufficient detail. The compile time test no longer happens when
249        PCRE is compiling a conditional subpattern, but actual runaway loops are
250        now caught at runtime (see 40 above).
251    
252    42. It seems that Perl allows any characters other than a closing parenthesis
253        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
254        has been changed to be the same.
255    
256    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
257        as not to get warnings when autogen.sh is called. Also changed
258        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
259    
260    44. To help people who use pcregrep to scan files containing exceedingly long
261        lines, the following changes have been made:
262    
263        (a) The default value of the buffer size parameter has been increased from
264            8K to 20K. (The actual buffer used is three times this size.)
265    
266        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
267            PCRE is built.
268    
269        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
270            to be set at run time.
271    
272        (d) Numerical values in pcregrep options can be followed by K or M, for
273            example --buffer-size=50K.
274    
275        (e) If a line being scanned overflows pcregrep's buffer, an error is now
276            given and the return code is set to 2.
277    
278    45. Add a pointer to the latest mark to the callout data block.
279    
280    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
281        partial match of an empty string instead of no match. This was specific to
282        the use of ".".
283    
284    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
285        complete match instead of a partial match. This bug was dependent on both
286        the PCRE_UTF8 and PCRE_DOTALL options being set.
287    
288    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
289        starting byte set, because \b was not being ignored.
290    
291    
292    Version 8.12 15-Jan-2011
293    ------------------------
294    
295    1.  Fixed some typos in the markup of the man pages, and wrote a script that
296        checks for such things as part of the documentation building process.
297    
298    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
299        --match-limit and --recursion-limit options (added for 8.11). In
300        particular, this made one of the standard tests fail. (The integer value
301        went into the wrong half of a long int.)
302    
303    3.  If the --colour option was given to pcregrep with -v (invert match), it
304        did strange things, either producing crazy output, or crashing. It should,
305        of course, ignore a request for colour when reporting lines that do not
306        match.
307    
308    4.  Another pcregrep bug caused similar problems if --colour was specified with
309        -M (multiline) and the pattern match finished with a line ending.
310    
311    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
312        matched in multiline mode, the following line was shown as part of the
313        match. This seems wrong, so I have changed it.
314    
315    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
316        the check for further matches in the same line (so they could be coloured)
317        to overrun the end of the current line. If another match was found, it was
318        incorrectly shown (and then shown again when found in the next line).
319    
320    7.  If pcregrep was compiled under Windows, there was a reference to the
321        function pcregrep_exit() before it was defined. I am assuming this was
322        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
323        reported by a user. I've moved the definition above the reference.
324    
325    
326    Version 8.11 10-Dec-2010
327    ------------------------
328    
329    1.  (*THEN) was not working properly if there were untried alternatives prior
330        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
331        backtracked to try for "b" instead of moving to the next alternative branch
332        at the same level (in this case, to look for "c"). The Perl documentation
333        is clear that when (*THEN) is backtracked onto, it goes to the "next
334        alternative in the innermost enclosing group".
335    
336    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
337        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
338        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
339        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
340        (*THEN).
341    
342    3.  If \s appeared in a character class, it removed the VT character from
343        the class, even if it had been included by some previous item, for example
344        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
345        of \s, but is part of the POSIX "space" class.)
346    
347    4.  A partial match never returns an empty string (because you can always
348        match an empty string at the end of the subject); however the checking for
349        an empty string was starting at the "start of match" point. This has been
350        changed to the "earliest inspected character" point, because the returned
351        data for a partial match starts at this character. This means that, for
352        example, /(?<=abc)def/ gives a partial match for the subject "abc"
353        (previously it gave "no match").
354    
355    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
356        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
357        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
358        has an implication that the given string is incomplete (because a partial
359        match is preferred over a full match). For this reason, these items now
360        give a partial match in this situation. [Aside: previously, the one case
361        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
362        match rather than a full match, which was wrong by the old rules, but is
363        now correct.]
364    
365    6.  There was a bug in the handling of #-introduced comments, recognized when
366        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
367        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
368        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
369        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
370        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
371        places in pcre_compile().
372    
373    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
374        comments when looking ahead for named forward references to subpatterns,
375        the only newline sequence it recognized was NL. It now handles newlines
376        according to the set newline convention.
377    
378    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
379        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
380        cater for a lack of strerror(). These oversights have been fixed.
381    
382    9.  Added --match-limit and --recursion-limit to pcregrep.
383    
384    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
385    
386    11. When the -o option was used, pcregrep was setting a return code of 1, even
387        when matches were found, and --line-buffered was not being honoured.
388    
389    12. Added an optional parentheses number to the -o and --only-matching options
390        of pcregrep.
391    
392    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
393        can match an empty string. The code to do it in pcretest and pcredemo
394        needed fixing:
395    
396        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
397            only one byte after an empty string match just before CRLF (this case
398            just got forgotten; "any" and "anycrlf" were OK).
399    
400        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
401            mode when an empty string match preceded an ASCII character followed by
402            a non-ASCII character. (The code for advancing by one character rather
403            than one byte was nonsense.)
404    
405        (c) The pcredemo.c sample program did not have any code at all to handle
406            the cases when CRLF is a valid newline sequence.
407    
408    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
409        as a starting offset was within the subject string. There is now a new
410        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
411        negative or greater than the length of the string. In order to test this,
412        pcretest is extended to allow the setting of negative starting offsets.
413    
414    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
415        starting offset points to the beginning of a UTF-8 character was
416        unnecessarily clumsy. I tidied it up.
417    
418    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
419        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
420    
421    17. Nobody had reported that the --include_dir option, which was added in
422        release 7.7 should have been called --include-dir (hyphen, not underscore)
423        for compatibility with GNU grep. I have changed it to --include-dir, but
424        left --include_dir as an undocumented synonym, and the same for
425        --exclude-dir, though that is not available in GNU grep, at least as of
426        release 2.5.4.
427    
428    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
429        characters from a string of bytes) have been redefined so as not to use
430        loops, in order to improve performance in some environments. At the same
431        time, I abstracted some of the common code into auxiliary macros to save
432        repetition (this should not affect the compiled code).
433    
434    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
435        compile-time error is now given if \c is not followed by an ASCII
436        character, that is, a byte less than 128. (In EBCDIC mode, the code is
437        different, and any byte value is allowed.)
438    
439    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
440        START_OPTIMIZE option, which is now allowed at compile time - but just
441        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
442        to pcregrep and other applications that have no direct access to PCRE
443        options. The new /Y option in pcretest sets this option when calling
444        pcre_compile().
445    
446    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
447        back references. Groups containing recursive back references were forced to
448        be atomic by that change, but in the case of named groups, the amount of
449        memory required was incorrectly computed, leading to "Failed: internal
450        error: code overflow". This has been fixed.
451    
452    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
453        pcretest.c, to avoid build problems in some Borland environments.
454    
455    
456    Version 8.10 25-Jun-2010
457    ------------------------
458    
459    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
460        THEN.
461    
462    2.  (*ACCEPT) was not working when inside an atomic group.
463    
464    3.  Inside a character class, \B is treated as a literal by default, but
465        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
466        causes the error). The code is unchanged, but I tidied the documentation.
467    
468    4.  Inside a character class, PCRE always treated \R and \X as literals,
469        whereas Perl faults them if its -w option is set. I have changed PCRE so
470        that it faults them when PCRE_EXTRA is set.
471    
472    5.  Added support for \N, which always matches any character other than
473        newline. (It is the same as "." when PCRE_DOTALL is not set.)
474    
475    6.  When compiling pcregrep with newer versions of gcc which may have
476        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
477        declared with attribute warn_unused_result" were given. Just casting the
478        result to (void) does not stop the warnings; a more elaborate fudge is
479        needed. I've used a macro to implement this.
480    
481    7.  Minor change to pcretest.c to avoid a compiler warning.
482    
483    8.  Added four artifical Unicode properties to help with an option to make
484        \s etc use properties (see next item). The new properties are: Xan
485        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
486    
487    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
488        use Unicode properties. (*UCP) at the start of a pattern can be used to set
489        this option. Modified pcretest to add /W to test this facility. Added
490        REG_UCP to make it available via the POSIX interface.
491    
492    10. Added --line-buffered to pcregrep.
493    
494    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
495        studied, and the match started with a letter with a code point greater than
496        127 whose first byte was different to the first byte of the other case of
497        the letter, the other case of this starting letter was not recognized
498        (#976).
499    
500    12. If a pattern that was studied started with a repeated Unicode property
501        test, for example, \p{Nd}+, there was the theoretical possibility of
502        setting up an incorrect bitmap of starting bytes, but fortunately it could
503        not have actually happened in practice until change 8 above was made (it
504        added property types that matched character-matching opcodes).
505    
506    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
507        possible starting bytes for non-anchored patterns.
508    
509    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
510        \R, and also a number of cases that involve Unicode properties, both
511        explicit and implicit when PCRE_UCP is set.
512    
513    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
514        input, it could crash or give wrong results if characters with values
515        greater than 0xc0 were present in the subject string. (Detail: it assumed
516        UTF-8 input when processing these items.)
517    
518    16. Added a lot of (int) casts to avoid compiler warnings in systems where
519        size_t is 64-bit (#991).
520    
521    17. Added a check for running out of memory when PCRE is compiled with
522        --disable-stack-for-recursion (#990).
523    
524    18. If the last data line in a file for pcretest does not have a newline on
525        the end, a newline was missing in the output.
526    
527    19. The default pcre_chartables.c file recognizes only ASCII characters (values
528        less than 128) in its various bitmaps. However, there is a facility for
529        generating tables according to the current locale when PCRE is compiled. It
530        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
531        characters, are recognized by isspace() and therefore were getting set in
532        these tables, and indeed these tables seem to approximate to ISO 8859. This
533        caused a problem in UTF-8 mode when pcre_study() was used to create a list
534        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
535        which of course cannot start UTF-8 characters. I have changed the code so
536        that only real ASCII characters (less than 128) and the correct starting
537        bytes for UTF-8 encodings are set for characters greater than 127 when in
538        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
539        altogether.)
540    
541    20. Added the /T option to pcretest so as to be able to run tests with non-
542        standard character tables, thus making it possible to include the tests
543        used for 19 above in the standard set of tests.
544    
545    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
546        reference to a subpattern the other side of a comment that contains an
547        opening parenthesis caused either an internal compiling error, or a
548        reference to the wrong subpattern.
549    
550    
551    Version 8.02 19-Mar-2010
552    ------------------------
553    
554    1.  The Unicode data tables have been updated to Unicode 5.2.0.
555    
556    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
557        configured.
558    
559    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
560        original author of that file, following a query about its status.
561    
562    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
563        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
564    
565    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
566        quantifier applied to a forward-referencing subroutine call, could compile
567        incorrect code or give the error "internal error: previously-checked
568        referenced subpattern not found".
569    
570    6.  Both MS Visual Studio and Symbian OS have problems with initializing
571        variables to point to external functions. For these systems, therefore,
572        pcre_malloc etc. are now initialized to local functions that call the
573        relevant global functions.
574    
575    7.  There were two entries missing in the vectors called coptable and poptable
576        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
577        I've fixed the data, and added a kludgy way of testing at compile time that
578        the lengths are correct (equal to the number of opcodes).
579    
580    8.  Following on from 7, I added a similar kludge to check the length of the
581        eint vector in pcreposix.c.
582    
583    9.  Error texts for pcre_compile() are held as one long string to avoid too
584        much relocation at load time. To find a text, the string is searched,
585        counting zeros. There was no check for running off the end of the string,
586        which could happen if a new error number was added without updating the
587        string.
588    
589    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
590    
591    11. \K was not working if it appeared in an atomic group or in a group that
592        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
593        \K is "not well defined" if used in an assertion. PCRE now accepts it if
594        the assertion is positive, but not if it is negative.
595    
596    12. Change 11 fortuitously reduced the size of the stack frame used in the
597        "match()" function of pcre_exec.c by one pointer. Forthcoming
598        implementation of support for (*MARK) will need an extra pointer on the
599        stack; I have reserved it now, so that the stack frame size does not
600        decrease.
601    
602    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
603        item in branch that calls a recursion is a subroutine call - as in the
604        second branch in the above example - was incorrectly given the compile-
605        time error "recursive call could loop indefinitely" because pcre_compile()
606        was not correctly checking the subroutine for matching a non-empty string.
607    
608    14. The checks for overrunning compiling workspace could trigger after an
609        overrun had occurred. This is a "should never occur" error, but it can be
610        triggered by pathological patterns such as hundreds of nested parentheses.
611        The checks now trigger 100 bytes before the end of the workspace.
612    
613    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
614    
615    
616    Version 8.01 19-Jan-2010
617    ------------------------
618    
619    1.  If a pattern contained a conditional subpattern with only one branch (in
620        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
621        computed the wrong minimum data length (which is of course zero for such
622        subpatterns). This could cause incorrect "no match" results.
623    
624    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
625        the pattern is reset in the first branch, pcre_compile() failed with
626        "internal error: code overflow at offset...". This happened only when
627        the reset was to the original external option setting. (An optimization
628        abstracts leading options settings into an external setting, which was the
629        cause of this.)
630    
631    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
632        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
633        assertion pattern did not match (meaning that the assertion was true), it
634        was incorrectly treated as false if the SKIP had been reached during the
635        matching. This also applied to assertions used as conditions.
636    
637    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
638        assertion subpattern, including such a pattern used as a condition,
639        unpredictable results occurred, instead of the error return
640        PCRE_ERROR_DFA_UITEM.
641    
642    5.  The C++ GlobalReplace function was not working like Perl for the special
643        situation when an empty string is matched. It now does the fancy magic
644        stuff that is necessary.
645    
646    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
647        removed. (These were left over from very, very early versions of PCRE.)
648    
649    7.  Some cosmetic changes to the code to make life easier when compiling it
650        as part of something else:
651    
652        (a) Change DEBUG to PCRE_DEBUG.
653    
654        (b) In pcre_compile(), rename the member of the "branch_chain" structure
655            called "current" as "current_branch", to prevent a collision with the
656            Linux macro when compiled as a kernel module.
657    
658        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
659            prevent a collision with the Linux macro when compiled as a kernel
660            module.
661    
662    8.  In pcre_compile() there are some checks for integer overflows that used to
663        cast potentially large values to (double). This has been changed to that
664        when building, a check for int64_t is made, and if it is found, it is used
665        instead, thus avoiding the use of floating point arithmetic. (There is no
666        other use of FP in PCRE.) If int64_t is not found, the fallback is to
667        double.
668    
669    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
670        2005 (difference between two addresses compared to an unsigned value).
671    
672    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
673        custom one, because of the following reported problem in Windows:
674    
675          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
676              under Win32.
677          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
678              therefore missing the function definition.
679          - The compiler thus generates a "C" signature for the test function.
680          - The linker fails to find the "C" function.
681          - PCRE fails to configure if asked to do so against libbz2.
682    
683    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
684        messages were output:
685    
686          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
687          rerunning libtoolize, to keep the correct libtool macros in-tree.
688          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
689    
690        I have done both of these things.
691    
692    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
693        most of the time, it *can* run out if it is given a pattern that contains a
694        runaway infinite recursion. I updated the discussion in the pcrestack man
695        page.
696    
697    13. Now that we have gone to the x.xx style of version numbers, the minor
698        version may start with zero. Using 08 or 09 is a bad idea because users
699        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
700        interpreted as invalid octal numbers. I've updated the previous comment in
701        configure.ac, and also added a check that gives an error if 08 or 09 are
702        used.
703    
704    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
705        causing partial matching to fail when the end of the subject matched \W
706        in a UTF-8 pattern where \W was quantified with a minimum of 3.
707    
708    15. There were some discrepancies between the declarations in pcre_internal.h
709        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
710        their definitions. The declarations used "const uschar *" and the
711        definitions used USPTR. Even though USPTR is normally defined as "const
712        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
713        reported that: "This difference in casting confuses some C++ compilers, for
714        example, SunCC recognizes above declarations as different functions and
715        generates broken code for hbpcre." I have changed the declarations to use
716        USPTR.
717    
718    16. GNU libtool is named differently on some systems. The autogen.sh script now
719        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
720        (FreeBSD).
721    
722    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
723        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
724        comment: "Figure out how to create a longlong from a string: strtoll and
725        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
726        instance, but it only takes 2 args instead of 3!"
727    
728    18. A subtle bug concerned with back references has been fixed by a change of
729        specification, with a corresponding code fix. A pattern such as
730        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
731        refers, was giving matches when it shouldn't. For example, xa=xaaa would
732        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
733        same bug. Such groups have to be quantified to be useful, or contained
734        inside another quantified group. (If there's no repetition, the reference
735        can never match.) The problem arises because, having left the group and
736        moved on to the rest of the pattern, a later failure that backtracks into
737        the group uses the captured value from the final iteration of the group
738        rather than the correct earlier one. I have fixed this in PCRE by forcing
739        any group that contains a reference to itself to be an atomic group; that
740        is, there cannot be any backtracking into it once it has completed. This is
741        similar to recursive and subroutine calls.
742    
743    
744    Version 8.00 19-Oct-09
745    ----------------------
746    
747    1.  The table for translating pcre_compile() error codes into POSIX error codes
748        was out-of-date, and there was no check on the pcre_compile() error code
749        being within the table. This could lead to an OK return being given in
750        error.
751    
752    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
753        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
754        in a Windows environment.
755    
756    3.  The pcregrep --count option prints the count for each file even when it is
757        zero, as does GNU grep. However, pcregrep was also printing all files when
758        --files-with-matches was added. Now, when both options are given, it prints
759        counts only for those files that have at least one match. (GNU grep just
760        prints the file name in this circumstance, but including the count seems
761        more useful - otherwise, why use --count?) Also ensured that the
762        combination -clh just lists non-zero counts, with no names.
763    
764    4.  The long form of the pcregrep -F option was incorrectly implemented as
765        --fixed_strings instead of --fixed-strings. This is an incompatible change,
766        but it seems right to fix it, and I didn't think it was worth preserving
767        the old behaviour.
768    
769    5.  The command line items --regex=pattern and --regexp=pattern were not
770        recognized by pcregrep, which required --regex pattern or --regexp pattern
771        (with a space rather than an '='). The man page documented the '=' forms,
772        which are compatible with GNU grep; these now work.
773    
774    6.  No libpcreposix.pc file was created for pkg-config; there was just
775        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
776    
777    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
778        when UCP support is not needed, by modifying the Python script that
779        generates it from Unicode data files. This should not matter if the module
780        is correctly used as a library, but I received one complaint about 50K of
781        unwanted data. My guess is that the person linked everything into his
782        program rather than using a library. Anyway, it does no harm.
783    
784    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
785        was a minimum greater than 1 for a wide character in a possessive
786        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
787        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
788        character. Chaos in the form of incorrect output or a compiling loop could
789        result.
790    
791    9.  The restrictions on what a pattern can contain when partial matching is
792        requested for pcre_exec() have been removed. All patterns can now be
793        partially matched by this function. In addition, if there are at least two
794        slots in the offset vector, the offset of the earliest inspected character
795        for the match and the offset of the end of the subject are set in them when
796        PCRE_ERROR_PARTIAL is returned.
797    
798    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
799        synonymous with PCRE_PARTIAL, for backwards compatibility, and
800        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
801        and may be more useful for multi-segment matching.
802    
803    11. Partial matching with pcre_exec() is now more intuitive. A partial match
804        used to be given if ever the end of the subject was reached; now it is
805        given only if matching could not proceed because another character was
806        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
807        string "Z", which now yields "no match" instead of "partial match". In the
808        case of pcre_dfa_exec(), "no match" is given if every matching path for the
809        final character ended with (*FAIL).
810    
811    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
812        if the pattern had a "must contain" character that was already found in the
813        earlier partial match, unless partial matching was again requested. For
814        example, with the pattern /dog.(body)?/, the "must contain" character is
815        "g". If the first part-match was for the string "dog", restarting with
816        "sbody" failed. This bug has been fixed.
817    
818    13. The string returned by pcre_dfa_exec() after a partial match has been
819        changed so that it starts at the first inspected character rather than the
820        first character of the match. This makes a difference only if the pattern
821        starts with a lookbehind assertion or \b or \B (\K is not supported by
822        pcre_dfa_exec()). It's an incompatible change, but it makes the two
823        matching functions compatible, and I think it's the right thing to do.
824    
825    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
826        so that the demonstration program is easily available in environments where
827        PCRE has not been installed from source.
828    
829    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
830        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
831        library.
832    
833    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
834        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
835        is not the first non-POSIX option to be added. Clearly some people find
836        these options useful.
837    
838    17. If a caller to the POSIX matching function regexec() passes a non-zero
839        value for nmatch with a NULL value for pmatch, the value of
840        nmatch is forced to zero.
841    
842    18. RunGrepTest did not have a test for the availability of the -u option of
843        the diff command, as RunTest does. It now checks in the same way as
844        RunTest, and also checks for the -b option.
845    
846    19. If an odd number of negated classes containing just a single character
847        interposed, within parentheses, between a forward reference to a named
848        subpattern and the definition of the subpattern, compilation crashed with
849        an internal error, complaining that it could not find the referenced
850        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
851        [The bug was that it was starting one character too far in when skipping
852        over the character class, thus treating the ] as data rather than
853        terminating the class. This meant it could skip too much.]
854    
855    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
856        /g option in pcretest when the pattern contains \K, which makes it possible
857        to have an empty string match not at the start, even when the pattern is
858        anchored. Updated pcretest and pcredemo to use this option.
859    
860    21. If the maximum number of capturing subpatterns in a recursion was greater
861        than the maximum at the outer level, the higher number was returned, but
862        with unset values at the outer level. The correct (outer level) value is
863        now given.
864    
865    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
866        PCRE did not set those parentheses (unlike Perl). I have now found a way to
867        make it do so. The string so far is captured, making this feature
868        compatible with Perl.
869    
870    23. The tests have been re-organized, adding tests 11 and 12, to make it
871        possible to check the Perl 5.10 features against Perl 5.10.
872    
873    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
874        pattern matches a fixed length string. PCRE did not allow this; now it
875        does. Neither allows recursion.
876    
877    25. I finally figured out how to implement a request to provide the minimum
878        length of subject string that was needed in order to match a given pattern.
879        (It was back references and recursion that I had previously got hung up
880        on.) This code has now been added to pcre_study(); it finds a lower bound
881        to the length of subject needed. It is not necessarily the greatest lower
882        bound, but using it to avoid searching strings that are too short does give
883        some useful speed-ups. The value is available to calling programs via
884        pcre_fullinfo().
885    
886    26. While implementing 25, I discovered to my embarrassment that pcretest had
887        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
888        study optimizations had never been tested with that matching function.
889        Oops. What is worse, even when it was passed study data, there was a bug in
890        pcre_dfa_exec() that meant it never actually used it. Double oops. There
891        were also very few tests of studied patterns with pcre_dfa_exec().
892    
893    27. If (?| is used to create subpatterns with duplicate numbers, they are now
894        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
895        on the other side of the coin, they are no longer allowed to have different
896        names, because these cannot be distinguished in PCRE, and this has caused
897        confusion. (This is a difference from Perl.)
898    
899    28. When duplicate subpattern names are present (necessarily with different
900        numbers, as required by 27 above), and a test is made by name in a
901        conditional pattern, either for a subpattern having been matched, or for
902        recursion in such a pattern, all the associated numbered subpatterns are
903        tested, and the overall condition is true if the condition is true for any
904        one of them. This is the way Perl works, and is also more like the way
905        testing by number works.
906    
907    
908    Version 7.9 11-Apr-09
909    ---------------------
910    
911    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
912        (pcretest), all targets were linked against these libraries. This included
913        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
914        libraries. This caused unwanted dependencies to be created. This problem
915        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
916        pcretest is linked with readline.
917    
918    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
919        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
920        moved outside it again, because FALSE and TRUE are already defined in AIX,
921        but BOOL is not.
922    
923    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
924        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
925    
926    4.  The pcregrep documentation said spaces were inserted as well as colons (or
927        hyphens) following file names and line numbers when outputting matching
928        lines. This is not true; no spaces are inserted. I have also clarified the
929        wording for the --colour (or --color) option.
930    
931    5.  In pcregrep, when --colour was used with -o, the list of matching strings
932        was not coloured; this is different to GNU grep, so I have changed it to be
933        the same.
934    
935    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
936        each matching line was coloured. Now it goes on to look for further matches
937        of any of the test patterns, which is the same behaviour as GNU grep.
938    
939    7.  A pattern that could match an empty string could cause pcregrep to loop; it
940        doesn't make sense to accept an empty string match in pcregrep, so I have
941        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
942        seems to be how GNU grep behaves.
943    
944    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
945        start or after a newline", because the conditional assertion was not being
946        correctly handled. The rule now is that both the assertion and what follows
947        in the first alternative must satisfy the test.
948    
949    9.  If auto-callout was enabled in a pattern with a conditional group whose
950        condition was an assertion, PCRE could crash during matching, both with
951        pcre_exec() and pcre_dfa_exec().
952    
953    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
954        used for matching.
955    
956    11. Unicode property support in character classes was not working for
957        characters (bytes) greater than 127 when not in UTF-8 mode.
958    
959    12. Added the -M command line option to pcretest.
960    
961    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
962    
963    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
964    
965    16. Added comments and documentation about mis-use of no_arg in the C++
966        wrapper.
967    
968    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
969        from Martin Jerabek that uses macro names for all relevant character and
970        string constants.
971    
972    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
973        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
974        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
975        these, but not everybody uses configure.
976    
977    19. A conditional group that had only one branch was not being correctly
978        recognized as an item that could match an empty string. This meant that an
979        enclosing group might also not be so recognized, causing infinite looping
980        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
981        with the subject "ab", where knowledge that the repeated group can match
982        nothing is needed in order to break the loop.
983    
984    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
985        exec(), but without supplying a callout function, matching went wrong.
986    
987    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
988        leak if the size of the offset vector was greater than 30. When the vector
989        is smaller, the saved offsets during recursion go onto a local stack
990        vector, but for larger vectors malloc() is used. It was failing to free
991        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
992        error, in fact).
993    
994    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
995        heapframe that is used only when UTF-8 support is enabled. This caused no
996        problem, but was untidy.
997    
998    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
999        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1000        included within another project.
1001    
1002    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1003        slightly modified by me:
1004    
1005          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1006              not building pcregrep.
1007    
1008          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1009              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1010    
1011    25. Forward references, both numeric and by name, in patterns that made use of
1012        duplicate group numbers, could behave incorrectly or give incorrect errors,
1013        because when scanning forward to find the reference group, PCRE was not
1014        taking into account the duplicate group numbers. A pattern such as
1015        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1016    
1017    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1018        the feature of a custom pointer more persuasive (as requested by a user).
1019    
1020    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1021        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1022        pre-defined.
1023    
1024    28. Added support for (*UTF8) at the start of a pattern.
1025    
1026    29. Arrange for flags added by the "release type" setting in CMake to be shown
1027        in the configuration summary.
1028    
1029    
1030    Version 7.8 05-Sep-08
1031    ---------------------
1032    
1033    1.  Replaced UCP searching code with optimized version as implemented for Ad
1034        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1035        stage table and inline lookup instead of a function, giving speed ups of 2
1036        to 5 times on some simple patterns that I tested. Permission was given to
1037        distribute the MultiStage2.py script that generates the tables (it's not in
1038        the tarball, but is in the Subversion repository).
1039    
1040    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1041        scripts.
1042    
1043    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1044        a group with a zero qualifier. The result of the study could be incorrect,
1045        or the function might crash, depending on the pattern.
1046    
1047    4.  Caseless matching was not working for non-ASCII characters in back
1048        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1049        It now works when Unicode Property Support is available.
1050    
1051    5.  In pcretest, an escape such as \x{de} in the data was always generating
1052        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1053        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1054        truncation.
1055    
1056    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1057    
1058    7.  Added two (int) casts to pcregrep when printing the difference of two
1059        pointers, in case they are 64-bit values.
1060    
1061    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1062        test 2 if it fails.
1063    
1064    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1065        and a #define of that name to empty if it is not externally set. This is to
1066        allow users of MSVC to set it if necessary.
1067    
1068    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1069        the convenience functions in the pcre_get.c source file.
1070    
1071    11. An option change at the start of a pattern that had top-level alternatives
1072        could cause overwriting and/or a crash. This command provoked a crash in
1073        some environments:
1074    
1075          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1076    
1077        This potential security problem was recorded as CVE-2008-2371.
1078    
1079    12. For a pattern where the match had to start at the beginning or immediately
1080        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1081        pcre_dfa_exec() could read past the end of the passed subject if there was
1082        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1083        pcretest so that it places the subject at the end of its malloc-ed buffer.
1084    
1085    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1086        exec() might read past the end of the data buffer in UTF-8 mode.
1087    
1088    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1089        the data contained the byte 0x85 as part of a UTF-8 character within its
1090        first line. This applied both to normal and DFA matching.
1091    
1092    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1093        /^[^d]*?$/8 failed to match "abc".
1094    
1095    16. Added a missing copyright notice to pcrecpp_internal.h.
1096    
1097    17. Make it more clear in the documentation that values returned from
1098        pcre_exec() in ovector are byte offsets, not character counts.
1099    
1100    18. Tidied a few places to stop certain compilers from issuing warnings.
1101    
1102    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1103        supplied by Stefan Weber. I made a further small update for 7.8 because
1104        there is a change of source arrangements: the pcre_searchfuncs.c module is
1105        replaced by pcre_ucd.c.
1106    
1107    
1108    Version 7.7 07-May-08
1109    ---------------------
1110    
1111    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1112        a string to a long long, pretend we don't even have a long long." This is
1113        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1114    
1115    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1116        pre-7.6 versions, which defined a global no_arg variable instead of putting
1117        it in the RE class. (See also #8 below.)
1118    
1119    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1120        Lopes.
1121    
1122    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1123    
1124        (1) The include/exclude patterns were being applied to the whole pathnames
1125            of files, instead of just to the final components.
1126    
1127        (2) If there was more than one level of directory, the subdirectories were
1128            skipped unless they satisfied the include/exclude conditions. This is
1129            inconsistent with GNU grep (and could even be seen as contrary to the
1130            pcregrep specification - which I improved to make it absolutely clear).
1131            The action now is always to scan all levels of directory, and just
1132            apply the include/exclude patterns to regular files.
1133    
1134    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1135        --exclude_dir in the tests to avoid scanning .svn directories.
1136    
1137    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1138        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1139        doesn't support NULs in patterns.
1140    
1141    7.  Added some missing "const"s to declarations of static tables in
1142        pcre_compile.c and pcre_dfa_exec.c.
1143    
1144    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1145        caused by fix #2  above. (Subsequently also a second patch to fix the
1146        first patch. And a third patch - this was a messy problem.)
1147    
1148    9.  Applied Craig's patch to remove the use of push_back().
1149    
1150    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1151        matching function regexec().
1152    
1153    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1154        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1155        references. PCRE supports relative numbers with this syntax (I don't think
1156        Oniguruma does).
1157    
1158    12. Previously, a group with a zero repeat such as (...){0} was completely
1159        omitted from the compiled regex. However, this means that if the group
1160        was called as a subroutine from elsewhere in the pattern, things went wrong
1161        (an internal error was given). Such groups are now left in the compiled
1162        pattern, with a new opcode that causes them to be skipped at execution
1163        time.
1164    
1165    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1166        to the way PCRE behaves:
1167    
1168        (a) A lone ] character is dis-allowed (Perl treats it as data).
1169    
1170        (b) A back reference to an unmatched subpattern matches an empty string
1171            (Perl fails the current match path).
1172    
1173        (c) A data ] in a character class must be notated as \] because if the
1174            first data character in a class is ], it defines an empty class. (In
1175            Perl it is not possible to have an empty class.) The empty class []
1176            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1177            The negative empty class [^] matches any one character, independently
1178            of the DOTALL setting.
1179    
1180    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1181        non-existent subpattern following a character class starting with ']' and
1182        containing () gave an internal compiling error instead of "reference to
1183        non-existent subpattern". Fortunately, when the pattern did exist, the
1184        compiled code was correct. (When scanning forwards to check for the
1185        existencd of the subpattern, it was treating the data ']' as terminating
1186        the class, so got the count wrong. When actually compiling, the reference
1187        was subsequently set up correctly.)
1188    
1189    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1190        it was being rejected as not supported by pcre_dfa_exec(), even though
1191        other assertions are supported. I have made pcre_dfa_exec() support
1192        (*FAIL).
1193    
1194    16. The implementation of 13c above involved the invention of a new opcode,
1195        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1196        cannot be changed at match time, I realized I could make a small
1197        improvement to matching performance by compiling OP_ALLANY instead of
1198        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1199        on the OP_ANY path.
1200    
1201    17. Compiling pcretest on Windows with readline support failed without the
1202        following two fixes: (1) Make the unistd.h include conditional on
1203        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1204    
1205    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1206        ncurses library to be included for pcretest when ReadLine support is
1207        requested, but also to allow for it to be overridden. This patch came from
1208        Daniel Bergström.
1209    
1210    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1211        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1212        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1213        spotting this.
1214    
1215    
1216    Version 7.6 28-Jan-08
1217    ---------------------
1218    
1219    1.  A character class containing a very large number of characters with
1220        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1221        overflow.
1222    
1223    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1224        HAVE_LONG_LONG is not defined.
1225    
1226    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1227        bring them up to date and include new features. This patch includes:
1228    
1229        - Fixed PH's badly added libz and libbz2 support.
1230        - Fixed a problem with static linking.
1231        - Added pcredemo. [But later removed - see 7 below.]
1232        - Fixed dftables problem and added an option.
1233        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1234            HAVE_LONG_LONG.
1235        - Added readline support for pcretest.
1236        - Added an listing of the option settings after cmake has run.
1237    
1238    4.  A user submitted a patch to Makefile that makes it easy to create
1239        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1240        Makefile.am that cause it to include this special target, without
1241        affecting anything else. Note that the same mingw target plus all
1242        the other distribution libraries and programs are now supported
1243        when configuring with CMake (see 6 below) instead of with
1244        Configure/Make.
1245    
1246    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1247        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1248        exported in the Windows port". It has not yet been confirmed that the patch
1249        solves the problem, but it does no harm.
1250    
1251    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1252        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1253        with CMake, and also correct the comment about stack recursion.
1254    
1255    7.  Remove the automatic building of pcredemo from the ./configure system and
1256        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1257        of a program that users should build themselves after PCRE is installed, so
1258        building it automatically is not really right. What is more, it gave
1259        trouble in some build environments.
1260    
1261    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1262    
1263    
1264    Version 7.5 10-Jan-08
1265    ---------------------
1266    
1267    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1268        values in parens when parsing an RE using the C++ wrapper."
1269    
1270    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1271        Characters greater than 255 were excluded from the class instead of being
1272        included.
1273    
1274    3.  The same bug as (2) above applied to negated POSIX classes such as
1275        [:^space:].
1276    
1277    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1278        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1279        I have changed it.
1280    
1281    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1282        first named subpattern) and a construct such as (?&a) would reference the
1283        first named subpattern whose name started with "a" (in other words, the
1284        length check was missing). Both these problems are fixed. "Subpattern name
1285        expected" is now given for (?&) (a zero-length name), and this patch also
1286        makes it give the same error for \k'' (previously it complained that that
1287        was a reference to a non-existent subpattern).
1288    
1289    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1290        this is right because (?- can be followed by option settings as well as by
1291        digits. I have, however, made the messages clearer.
1292    
1293    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1294        than the number used in the conditional) now cause a compile-time error.
1295        This is actually not compatible with Perl, which accepts such patterns, but
1296        treats the conditional as always being FALSE (as PCRE used to), but it
1297        seems to me that giving a diagnostic is better.
1298    
1299    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1300        and messages.
1301    
1302    9.  Fix two occurrences of "backslash" in comments that should have been
1303        "backspace".
1304    
1305    10. Remove two redundant lines of code that can never be obeyed (their function
1306        was moved elsewhere).
1307    
1308    11. The program that makes PCRE's Unicode character property table had a bug
1309        which caused it to generate incorrect table entries for sequences of
1310        characters that have the same character type, but are in different scripts.
1311        It amalgamated them into a single range, with the script of the first of
1312        them. In other words, some characters were in the wrong script. There were
1313        thirteen such cases, affecting characters in the following ranges:
1314    
1315          U+002b0 - U+002c1
1316          U+0060c - U+0060d
1317          U+0061e - U+00612
1318          U+0064b - U+0065e
1319          U+0074d - U+0076d
1320          U+01800 - U+01805
1321          U+01d00 - U+01d77
1322          U+01d9b - U+01dbf
1323          U+0200b - U+0200f
1324          U+030fc - U+030fe
1325          U+03260 - U+0327f
1326          U+0fb46 - U+0fbb1
1327          U+10450 - U+1049d
1328    
1329    12. The -o option (show only the matching part of a line) for pcregrep was not
1330        compatible with GNU grep in that, if there was more than one match in a
1331        line, it showed only the first of them. It now behaves in the same way as
1332        GNU grep.
1333    
1334    13. If the -o and -v options were combined for pcregrep, it printed a blank
1335        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1336        does the same. The return code can be used to tell if there were any
1337        non-matching lines.
1338    
1339    14. Added --file-offsets and --line-offsets to pcregrep.
1340    
1341    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1342        infinitely looping recursion. The bug was that positive lookaheads were not
1343        being skipped when checking for a possible empty match (negative lookaheads
1344        and both kinds of lookbehind were skipped).
1345    
1346    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1347        inclusion of <windows.h> to before rather than after the definition of
1348        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1349    
1350    17. Specifying a possessive quantifier with a specific limit for a Unicode
1351        character property caused pcre_compile() to compile bad code, which led at
1352        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1353        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1354        caused the error; without that there was no problem.
1355    
1356    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1357    
1358    19. Added --enable-pcretest-libreadline.
1359    
1360    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1361        RE::GlobalReplace(). As a result, the number of replacements returned was
1362        double what it should be. I removed one of the increments, but Craig sent a
1363        later patch that removed the other one (the right fix) and added unit tests
1364        that check the return values (which was not done before).
1365    
1366    21. Several CMake things:
1367    
1368        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1369            the names libpcre and libpcreposix, not just pcre and pcreposix.
1370    
1371        (2) The above change means that pcretest and pcregrep are now correctly
1372            linked with the newly-built libraries, not previously installed ones.
1373    
1374        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1375    
1376    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1377        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1378        UTF-8 newline character). The key issue is that the pattern starts .*;
1379        this means that the match must be either at the beginning, or after a
1380        newline. The bug was in the code for advancing after a failed match and
1381        checking that the new position followed a newline. It was not taking
1382        account of UTF-8 characters correctly.
1383    
1384    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1385        character classes. PCRE was not treating the sequence [:...:] as a
1386        character class unless the ... were all letters. Perl, however, seems to
1387        allow any characters between [: and :], though of course it rejects as
1388        unknown any "names" that contain non-letters, because all the known class
1389        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1390        for example, whereas PCRE did not - it did not recognize a POSIX character
1391        class. This seemed a bit dangerous, so the code has been changed to be
1392        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1393        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1394        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1395        Perl does, and where it didn't before.
1396    
1397    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1398        Windows environments %n is disabled by default.
1399    
1400    
1401    Version 7.4 21-Sep-07
1402    ---------------------
1403    
1404    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1405        means that a class such as [\s] counted as "explicit reference to CR or
1406        LF". That isn't really right - the whole point of the change was to try to
1407        help when there was an actual mention of one of the two characters. So now
1408        the change happens only if \r or \n (or a literal CR or LF) character is
1409        encountered.
1410    
1411    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1412        of both had grown to the point where there were only 3 bits left.
1413        Fortunately, there was spare space in the data structure, and so I have
1414        moved the internal flags into a new 16-bit field to free up more option
1415        bits.
1416    
1417    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1418        but did not set the internal JCHANGED flag - either of these is enough to
1419        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1420        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1421        start sets both bits.
1422    
1423    4.  Added options (at build time, compile time, exec time) to change \R from
1424        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1425    
1426    5.  doc/pcresyntax.html was missing from the distribution.
1427    
1428    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1429        compatibility, even though it is no longer used.
1430    
1431    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1432        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1433        windows.h file is present (where different names are used). [This was
1434        reversed later after testing - see 16 below.]
1435    
1436    8.  Changed all #include <config.h> to #include "config.h". There were also
1437        some further <pcre.h> cases that I changed to "pcre.h".
1438    
1439    9.  When pcregrep was used with the --colour option, it missed the line ending
1440        sequence off the lines that it output.
1441    
1442    10. It was pointed out to me that arrays of string pointers cause lots of
1443        relocations when a shared library is dynamically loaded. A technique of
1444        using a single long string with a table of offsets can drastically reduce
1445        these. I have refactored PCRE in four places to do this. The result is
1446        dramatic:
1447    
1448          Originally:                          290
1449          After changing UCP table:            187
1450          After changing error message table:   43
1451          After changing table of "verbs"       36
1452          After changing table of Posix names   22
1453    
1454        Thanks to the folks working on Gregex for glib for this insight.
1455    
1456    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1457        unicode-properties was also set.
1458    
1459    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1460    
1461    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1462        checked only for CRLF.
1463    
1464    14. Added casts to pcretest.c to avoid compiler warnings.
1465    
1466    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1467    
1468    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1469        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1470        entirely. This removes changes made in 7 above.
1471    
1472    17. The CMake files have been updated, and there is now more information about
1473        building with CMake in the NON-UNIX-USE document.
1474    
1475    
1476    Version 7.3 28-Aug-07
1477  ---------------------  ---------------------
1478    
1479   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 145  Version 7.3 20-Aug-07 Line 1617  Version 7.3 20-Aug-07
1617    
1618  25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.  25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1619    
1620  26. Patterns such as [\P{Yi}A] which include \p or \P and just one other  26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1621      character were causing crashes (broken optimization).      character were causing crashes (broken optimization).
1622    
1623    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1624        \p or \P) caused a compile-time loop.
1625    
1626    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1627        break. For example, the unstudied pattern [\r\n]A does not match the string
1628        "\r\nA" because change 7.0/46 below moves the current point on by two
1629        characters after failing to match at the start. However, the pattern \nA
1630        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1631        the same is true. There doesn't seem any very clean way out of this, but
1632        what I have chosen to do makes the common cases work: PCRE now takes note
1633        of whether there can be an explicit match for \r or \n anywhere in the
1634        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1635        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1636        pattern has explicit CR or LF references.
1637    
1638    29. Added (*CR) etc for changing newline setting at start of pattern.
1639    
1640    
1641  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07
1642  ---------------------  ---------------------

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