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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.5 12-Nov-07  Version 8.21
5    ------------
6    
7    1.  Updating the JIT compiler.
8    
9    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
10        are added as well.
11    
12    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
13        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
14        calling _pcre_jit_exec. Some extra comments are added.
15    
16    4.  Mark settings inside atomic groups that do not contain any capturing
17        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
18        was introduced by change 18 for 8.20.
19    
20    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
21        ECMA-262 standard.
22    
23    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
24        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
25        This bug was probably introduced by change 9 of 8.13.
26    
27    7.  While fixing 6 above, I noticed that a number of other items were being
28        incorrectly rejected as "not fixed length". This arose partly because newer
29        opcodes had not been added to the fixed-length checking code. I have (a)
30        corrected the bug and added tests for these items, and (b) arranged for an
31        error to occur if an unknown opcode is encountered while checking for fixed
32        length instead of just assuming "not fixed length". The items that were
33        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
34        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
35        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
36    
37    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
38        being incorrectly compiled and would have given unpredicatble results.
39    
40    9.  A possessively repeated subpattern with minimum repeat count greater than
41        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
42        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
43        the first (A) could occur when it should not.
44    
45    10. Add a cast and remove a redundant test from the code.
46    
47    11. JIT should use pcre_malloc/pcre_free for allocation.
48    
49    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
50        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
51        is anything other than /usr, -L is still shown).
52    
53    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
54    
55    14. Perl does not support \N without a following name in a [] class; PCRE now
56        also gives an error.
57    
58    
59    Version 8.20 21-Oct-2011
60    ------------------------
61    
62    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
63        a POSIX class. After further experiments with Perl, which convinced me that
64        Perl has bugs and confusions, a closing square bracket is no longer allowed
65        in a POSIX name. This bug also affected patterns with classes that started
66        with full stops.
67    
68    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
69        captured substring, but while checking the failing first alternative,
70        substring 1 is temporarily captured. If the output vector supplied to
71        pcre_exec() was not big enough for this capture, the yield of the function
72        was still zero ("insufficient space for captured substrings"). This cannot
73        be totally fixed without adding another stack variable, which seems a lot
74        of expense for a edge case. However, I have improved the situation in cases
75        such as /(a)(b)x|abc/ matched against "abc", where the return code
76        indicates that fewer than the maximum number of slots in the ovector have
77        been set.
78    
79    3.  Related to (2) above: when there are more back references in a pattern than
80        slots in the output vector, pcre_exec() uses temporary memory during
81        matching, and copies in the captures as far as possible afterwards. It was
82        using the entire output vector, but this conflicts with the specification
83        that only 2/3 is used for passing back captured substrings. Now it uses
84        only the first 2/3, for compatibility. This is, of course, another edge
85        case.
86    
87    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
88        main code base, and can be used by building with --enable-jit. When this is
89        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
90        runtime --no-jit option is given.
91    
92    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
93        ovector, the return from the function was zero, implying that there were
94        other matches that did not fit. The correct "exactly full" value is now
95        returned.
96    
97    6.  If a subpattern that was called recursively or as a subroutine contained
98        (*PRUNE) or any other control that caused it to give a non-standard return,
99        invalid errors such as "Error -26 (nested recursion at the same subject
100        position)" or even infinite loops could occur.
101    
102    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
103        computing the minimum length on reaching *ACCEPT, and so ended up with the
104        wrong value of 1 rather than 0. Further investigation indicates that
105        computing a minimum subject length in the presence of *ACCEPT is difficult
106        (think back references, subroutine calls), and so I have changed the code
107        so that no minimum is registered for a pattern that contains *ACCEPT.
108    
109    8.  If (*THEN) was present in the first (true) branch of a conditional group,
110        it was not handled as intended. [But see 16 below.]
111    
112    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
113        Sheri Pierce.
114    
115    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
116        the first byte in a match must be "a".
117    
118    11. Change 17 for 8.13 increased the recursion depth for patterns like
119        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
120        pattern contains any instances of (*THEN). If it does not, the old
121        optimizations are restored. It would be nice to do this on a per-group
122        basis, but at the moment that is not feasible.
123    
124    12. In some environments, the output of pcretest -C is CRLF terminated. This
125        broke RunTest's code that checks for the link size. A single white space
126        character after the value is now allowed for.
127    
128    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
129        For "fr", it uses the Windows-specific input and output files.
130    
131    14. If (*THEN) appeared in a group that was called recursively or as a
132        subroutine, it did not work as intended. [But see next item.]
133    
134    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
135        pattern fragments (but not containing any | characters). If A and B are
136        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
137        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
138        D. In other words, Perl considers parentheses that do not contain any |
139        characters to be part of a surrounding alternative, whereas PCRE was
140        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
141        differently. PCRE now behaves in the same way as Perl, except in the case
142        of subroutine/recursion calls such as (?1) which have in any case always
143        been different (but PCRE had them first :-).
144    
145    16. Related to 15 above: Perl does not treat the | in a conditional group as
146        creating alternatives. Such a group is treated in the same way as an
147        ordinary group without any | characters when processing (*THEN). PCRE has
148        been changed to match Perl's behaviour.
149    
150    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
151        RunGrepTest script failed.
152    
153    18. Change 22 for version 13 caused atomic groups to use more stack. This is
154        inevitable for groups that contain captures, but it can lead to a lot of
155        stack use in large patterns. The old behaviour has been restored for atomic
156        groups that do not contain any capturing parentheses.
157    
158    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
159        suppress the check for a minimum subject length at run time. (If it was
160        given to pcre_exec() or pcre_dfa_exec() it did work.)
161    
162    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
163        fail to work when decoding hex characters in data strings in EBCDIC
164        environments.
165    
166    21. It appears that in at least one Mac OS environment, the isxdigit() function
167        is implemented as a macro that evaluates to its argument more than once,
168        contravening the C 90 Standard (I haven't checked a later standard). There
169        was an instance in pcretest which caused it to go wrong when processing
170        \x{...} escapes in subject strings. The has been rewritten to avoid using
171        things like p++ in the argument of isxdigit().
172    
173    
174    Version 8.13 16-Aug-2011
175    ------------------------
176    
177    1.  The Unicode data tables have been updated to Unicode 6.0.0.
178    
179    2.  Two minor typos in pcre_internal.h have been fixed.
180    
181    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
182        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
183        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
184    
185    4.  There were a number of related bugs in the code for matching backrefences
186        caselessly in UTF-8 mode when codes for the characters concerned were
187        different numbers of bytes. For example, U+023A and U+2C65 are an upper
188        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
189        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
190        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
191        2-byte code at the end of the subject (it thought there wasn't enough data
192        left).
193    
194    5.  Comprehensive information about what went wrong is now returned by
195        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
196        as the output vector has at least 2 elements. The offset of the start of
197        the failing character and a reason code are placed in the vector.
198    
199    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
200        now returned is for the first byte of the failing character, instead of the
201        last byte inspected. This is an incompatible change, but I hope it is small
202        enough not to be a problem. It makes the returned offset consistent with
203        pcre_exec() and pcre_dfa_exec().
204    
205    7.  pcretest now gives a text phrase as well as the error number when
206        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
207        failure, the offset and reason code are output.
208    
209    8.  When \R was used with a maximizing quantifier it failed to skip backwards
210        over a \r\n pair if the subsequent match failed. Instead, it just skipped
211        back over a single character (\n). This seems wrong (because it treated the
212        two characters as a single entity when going forwards), conflicts with the
213        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
214        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
215        has been changed.
216    
217    9.  Some internal refactoring has changed the processing so that the handling
218        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
219        time (the PCRE_DOTALL option was changed this way some time ago: version
220        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
221        which was always a bit of a fudge. It also means that there is one less
222        argument for the match() function, which reduces its stack requirements
223        slightly. This change also fixes an incompatibility with Perl: the pattern
224        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
225    
226    10. More internal refactoring has drastically reduced the number of recursive
227        calls to match() for possessively repeated groups such as (abc)++ when
228        using pcre_exec().
229    
230    11. While implementing 10, a number of bugs in the handling of groups were
231        discovered and fixed:
232    
233        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
234        (a|)*(?1) gave a compile-time internal error.
235        ((a|)+)+  did not notice that the outer group could match an empty string.
236        (^a|^)+   was not marked as anchored.
237        (.*a|.*)+ was not marked as matching at start or after a newline.
238    
239    12. Yet more internal refactoring has removed another argument from the match()
240        function. Special calls to this function are now indicated by setting a
241        value in a variable in the "match data" data block.
242    
243    13. Be more explicit in pcre_study() instead of relying on "default" for
244        opcodes that mean there is no starting character; this means that when new
245        ones are added and accidentally left out of pcre_study(), testing should
246        pick them up.
247    
248    14. The -s option of pcretest has been documented for ages as being an old
249        synonym of -m (show memory usage). I have changed it to mean "force study
250        for every regex", that is, assume /S for every regex. This is similar to -i
251        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
252        using it. It makes it easier to run collections of tests with and without
253        study enabled, and thereby test pcre_study() more easily. All the standard
254        tests are now run with and without -s (but some patterns can be marked as
255        "never study" - see 20 below).
256    
257    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
258        restoration of the capturing data to the outer values was not happening
259        correctly.
260    
261    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
262        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
263        pattern had matched an empty string, and so incorrectly returned a no
264        match.
265    
266    17. There was optimizing code for the last branch of non-capturing parentheses,
267        and also for the obeyed branch of a conditional subexpression, which used
268        tail recursion to cut down on stack usage. Unfortunately, now that there is
269        the possibility of (*THEN) occurring in these branches, tail recursion is
270        no longer possible because the return has to be checked for (*THEN). These
271        two optimizations have therefore been removed. [But see 8.20/11 above.]
272    
273    18. If a pattern containing \R was studied, it was assumed that \R always
274        matched two bytes, thus causing the minimum subject length to be
275        incorrectly computed because \R can also match just one byte.
276    
277    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
278        was incorrectly computed.
279    
280    20. If /S is present twice on a test pattern in pcretest input, it now
281        *disables* studying, thereby overriding the use of -s on the command line
282        (see 14 above). This is necessary for one or two tests to keep the output
283        identical in both cases.
284    
285    21. When (*ACCEPT) was used in an assertion that matched an empty string and
286        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
287    
288    22. When an atomic group that contained a capturing parenthesis was
289        successfully matched, but the branch in which it appeared failed, the
290        capturing was not being forgotten if a higher numbered group was later
291        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
292        group 1 to "a", when in fact it should be unset. This applied to multi-
293        branched capturing and non-capturing groups, repeated or not, and also to
294        positive assertions (capturing in negative assertions does not happen
295        in PCRE) and also to nested atomic groups.
296    
297    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
298        subject after a captured substring, to make it easier to tell which of a
299        number of identical substrings has been captured.
300    
301    24. The way atomic groups are processed by pcre_exec() has been changed so that
302        if they are repeated, backtracking one repetition now resets captured
303        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
304        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
305        "aaa". Previously, it would have been "a". As part of this code
306        refactoring, the way recursive calls are handled has also been changed.
307    
308    25. If an assertion condition captured any substrings, they were not passed
309        back unless some other capturing happened later. For example, if
310        (?(?=(a))a) was matched against "a", no capturing was returned.
311    
312    26. When studying a pattern that contained subroutine calls or assertions,
313        the code for finding the minimum length of a possible match was handling
314        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
315        group 1 called group 2 while simultaneously a separate group 2 called group
316        1). A stack overflow occurred in this case. I have fixed this by limiting
317        the recursion depth to 10.
318    
319    27. Updated RunTest.bat in the distribution to the version supplied by Tom
320        Fortmann. This supports explicit test numbers on the command line, and has
321        argument validation and error reporting.
322    
323    28. An instance of \X with an unlimited repeat could fail if at any point the
324        first character it looked at was a mark character.
325    
326    29. Some minor code refactoring concerning Unicode properties and scripts
327        should reduce the stack requirement of match() slightly.
328    
329    30. Added the '=' option to pcretest to check the setting of unused capturing
330        slots at the end of the pattern, which are documented as being -1, but are
331        not included in the return count.
332    
333    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
334        compiled something random. Now it gives a compile-time error (as does
335        Perl).
336    
337    32. A *MARK encountered during the processing of a positive assertion is now
338        recorded and passed back (compatible with Perl).
339    
340    33. If --only-matching or --colour was set on a pcregrep call whose pattern
341        had alternative anchored branches, the search for a second match in a line
342        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
343        matched the line "0102" twice. The same bug affected patterns that started
344        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
345        twice.
346    
347    34. Previously, PCRE did not allow quantification of assertions. However, Perl
348        does, and because of capturing effects, quantifying parenthesized
349        assertions may at times be useful. Quantifiers are now allowed for
350        parenthesized assertions.
351    
352    35. A minor code tidy in pcre_compile() when checking options for \R usage.
353    
354    36. \g was being checked for fancy things in a character class, when it should
355        just be a literal "g".
356    
357    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
358        appearance of a nested POSIX class supersedes an apparent external class.
359        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
360        unescaped square brackets may also appear as part of class names. For
361        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
362        more like Perl. (But see 8.20/1 above.)
363    
364    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
365        was because it thought it was \N{name}, which is not supported).
366    
367    39. Add minix to OS list not supporting the -S option in pcretest.
368    
369    40. PCRE tries to detect cases of infinite recursion at compile time, but it
370        cannot analyze patterns in sufficient detail to catch mutual recursions
371        such as ((?1))((?2)). There is now a runtime test that gives an error if a
372        subgroup is called recursively as a subpattern for a second time at the
373        same position in the subject string. In previous releases this might have
374        been caught by the recursion limit, or it might have run out of stack.
375    
376    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
377        happen only once. PCRE was, however incorrectly giving a compile time error
378        "recursive call could loop indefinitely" because it cannot analyze the
379        pattern in sufficient detail. The compile time test no longer happens when
380        PCRE is compiling a conditional subpattern, but actual runaway loops are
381        now caught at runtime (see 40 above).
382    
383    42. It seems that Perl allows any characters other than a closing parenthesis
384        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
385        has been changed to be the same.
386    
387    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
388        as not to get warnings when autogen.sh is called. Also changed
389        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
390    
391    44. To help people who use pcregrep to scan files containing exceedingly long
392        lines, the following changes have been made:
393    
394        (a) The default value of the buffer size parameter has been increased from
395            8K to 20K. (The actual buffer used is three times this size.)
396    
397        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
398            PCRE is built.
399    
400        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
401            to be set at run time.
402    
403        (d) Numerical values in pcregrep options can be followed by K or M, for
404            example --buffer-size=50K.
405    
406        (e) If a line being scanned overflows pcregrep's buffer, an error is now
407            given and the return code is set to 2.
408    
409    45. Add a pointer to the latest mark to the callout data block.
410    
411    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
412        partial match of an empty string instead of no match. This was specific to
413        the use of ".".
414    
415    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
416        complete match instead of a partial match. This bug was dependent on both
417        the PCRE_UTF8 and PCRE_DOTALL options being set.
418    
419    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
420        starting byte set, because \b was not being ignored.
421    
422    
423    Version 8.12 15-Jan-2011
424    ------------------------
425    
426    1.  Fixed some typos in the markup of the man pages, and wrote a script that
427        checks for such things as part of the documentation building process.
428    
429    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
430        --match-limit and --recursion-limit options (added for 8.11). In
431        particular, this made one of the standard tests fail. (The integer value
432        went into the wrong half of a long int.)
433    
434    3.  If the --colour option was given to pcregrep with -v (invert match), it
435        did strange things, either producing crazy output, or crashing. It should,
436        of course, ignore a request for colour when reporting lines that do not
437        match.
438    
439    4.  Another pcregrep bug caused similar problems if --colour was specified with
440        -M (multiline) and the pattern match finished with a line ending.
441    
442    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
443        matched in multiline mode, the following line was shown as part of the
444        match. This seems wrong, so I have changed it.
445    
446    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
447        the check for further matches in the same line (so they could be coloured)
448        to overrun the end of the current line. If another match was found, it was
449        incorrectly shown (and then shown again when found in the next line).
450    
451    7.  If pcregrep was compiled under Windows, there was a reference to the
452        function pcregrep_exit() before it was defined. I am assuming this was
453        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
454        reported by a user. I've moved the definition above the reference.
455    
456    
457    Version 8.11 10-Dec-2010
458    ------------------------
459    
460    1.  (*THEN) was not working properly if there were untried alternatives prior
461        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
462        backtracked to try for "b" instead of moving to the next alternative branch
463        at the same level (in this case, to look for "c"). The Perl documentation
464        is clear that when (*THEN) is backtracked onto, it goes to the "next
465        alternative in the innermost enclosing group".
466    
467    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
468        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
469        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
470        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
471        (*THEN).
472    
473    3.  If \s appeared in a character class, it removed the VT character from
474        the class, even if it had been included by some previous item, for example
475        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
476        of \s, but is part of the POSIX "space" class.)
477    
478    4.  A partial match never returns an empty string (because you can always
479        match an empty string at the end of the subject); however the checking for
480        an empty string was starting at the "start of match" point. This has been
481        changed to the "earliest inspected character" point, because the returned
482        data for a partial match starts at this character. This means that, for
483        example, /(?<=abc)def/ gives a partial match for the subject "abc"
484        (previously it gave "no match").
485    
486    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
487        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
488        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
489        has an implication that the given string is incomplete (because a partial
490        match is preferred over a full match). For this reason, these items now
491        give a partial match in this situation. [Aside: previously, the one case
492        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
493        match rather than a full match, which was wrong by the old rules, but is
494        now correct.]
495    
496    6.  There was a bug in the handling of #-introduced comments, recognized when
497        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
498        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
499        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
500        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
501        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
502        places in pcre_compile().
503    
504    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
505        comments when looking ahead for named forward references to subpatterns,
506        the only newline sequence it recognized was NL. It now handles newlines
507        according to the set newline convention.
508    
509    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
510        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
511        cater for a lack of strerror(). These oversights have been fixed.
512    
513    9.  Added --match-limit and --recursion-limit to pcregrep.
514    
515    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
516    
517    11. When the -o option was used, pcregrep was setting a return code of 1, even
518        when matches were found, and --line-buffered was not being honoured.
519    
520    12. Added an optional parentheses number to the -o and --only-matching options
521        of pcregrep.
522    
523    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
524        can match an empty string. The code to do it in pcretest and pcredemo
525        needed fixing:
526    
527        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
528            only one byte after an empty string match just before CRLF (this case
529            just got forgotten; "any" and "anycrlf" were OK).
530    
531        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
532            mode when an empty string match preceded an ASCII character followed by
533            a non-ASCII character. (The code for advancing by one character rather
534            than one byte was nonsense.)
535    
536        (c) The pcredemo.c sample program did not have any code at all to handle
537            the cases when CRLF is a valid newline sequence.
538    
539    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
540        as a starting offset was within the subject string. There is now a new
541        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
542        negative or greater than the length of the string. In order to test this,
543        pcretest is extended to allow the setting of negative starting offsets.
544    
545    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
546        starting offset points to the beginning of a UTF-8 character was
547        unnecessarily clumsy. I tidied it up.
548    
549    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
550        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
551    
552    17. Nobody had reported that the --include_dir option, which was added in
553        release 7.7 should have been called --include-dir (hyphen, not underscore)
554        for compatibility with GNU grep. I have changed it to --include-dir, but
555        left --include_dir as an undocumented synonym, and the same for
556        --exclude-dir, though that is not available in GNU grep, at least as of
557        release 2.5.4.
558    
559    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
560        characters from a string of bytes) have been redefined so as not to use
561        loops, in order to improve performance in some environments. At the same
562        time, I abstracted some of the common code into auxiliary macros to save
563        repetition (this should not affect the compiled code).
564    
565    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
566        compile-time error is now given if \c is not followed by an ASCII
567        character, that is, a byte less than 128. (In EBCDIC mode, the code is
568        different, and any byte value is allowed.)
569    
570    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
571        START_OPTIMIZE option, which is now allowed at compile time - but just
572        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
573        to pcregrep and other applications that have no direct access to PCRE
574        options. The new /Y option in pcretest sets this option when calling
575        pcre_compile().
576    
577    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
578        back references. Groups containing recursive back references were forced to
579        be atomic by that change, but in the case of named groups, the amount of
580        memory required was incorrectly computed, leading to "Failed: internal
581        error: code overflow". This has been fixed.
582    
583    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
584        pcretest.c, to avoid build problems in some Borland environments.
585    
586    
587    Version 8.10 25-Jun-2010
588    ------------------------
589    
590    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
591        THEN.
592    
593    2.  (*ACCEPT) was not working when inside an atomic group.
594    
595    3.  Inside a character class, \B is treated as a literal by default, but
596        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
597        causes the error). The code is unchanged, but I tidied the documentation.
598    
599    4.  Inside a character class, PCRE always treated \R and \X as literals,
600        whereas Perl faults them if its -w option is set. I have changed PCRE so
601        that it faults them when PCRE_EXTRA is set.
602    
603    5.  Added support for \N, which always matches any character other than
604        newline. (It is the same as "." when PCRE_DOTALL is not set.)
605    
606    6.  When compiling pcregrep with newer versions of gcc which may have
607        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
608        declared with attribute warn_unused_result" were given. Just casting the
609        result to (void) does not stop the warnings; a more elaborate fudge is
610        needed. I've used a macro to implement this.
611    
612    7.  Minor change to pcretest.c to avoid a compiler warning.
613    
614    8.  Added four artifical Unicode properties to help with an option to make
615        \s etc use properties (see next item). The new properties are: Xan
616        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
617    
618    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
619        use Unicode properties. (*UCP) at the start of a pattern can be used to set
620        this option. Modified pcretest to add /W to test this facility. Added
621        REG_UCP to make it available via the POSIX interface.
622    
623    10. Added --line-buffered to pcregrep.
624    
625    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
626        studied, and the match started with a letter with a code point greater than
627        127 whose first byte was different to the first byte of the other case of
628        the letter, the other case of this starting letter was not recognized
629        (#976).
630    
631    12. If a pattern that was studied started with a repeated Unicode property
632        test, for example, \p{Nd}+, there was the theoretical possibility of
633        setting up an incorrect bitmap of starting bytes, but fortunately it could
634        not have actually happened in practice until change 8 above was made (it
635        added property types that matched character-matching opcodes).
636    
637    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
638        possible starting bytes for non-anchored patterns.
639    
640    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
641        \R, and also a number of cases that involve Unicode properties, both
642        explicit and implicit when PCRE_UCP is set.
643    
644    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
645        input, it could crash or give wrong results if characters with values
646        greater than 0xc0 were present in the subject string. (Detail: it assumed
647        UTF-8 input when processing these items.)
648    
649    16. Added a lot of (int) casts to avoid compiler warnings in systems where
650        size_t is 64-bit (#991).
651    
652    17. Added a check for running out of memory when PCRE is compiled with
653        --disable-stack-for-recursion (#990).
654    
655    18. If the last data line in a file for pcretest does not have a newline on
656        the end, a newline was missing in the output.
657    
658    19. The default pcre_chartables.c file recognizes only ASCII characters (values
659        less than 128) in its various bitmaps. However, there is a facility for
660        generating tables according to the current locale when PCRE is compiled. It
661        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
662        characters, are recognized by isspace() and therefore were getting set in
663        these tables, and indeed these tables seem to approximate to ISO 8859. This
664        caused a problem in UTF-8 mode when pcre_study() was used to create a list
665        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
666        which of course cannot start UTF-8 characters. I have changed the code so
667        that only real ASCII characters (less than 128) and the correct starting
668        bytes for UTF-8 encodings are set for characters greater than 127 when in
669        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
670        altogether.)
671    
672    20. Added the /T option to pcretest so as to be able to run tests with non-
673        standard character tables, thus making it possible to include the tests
674        used for 19 above in the standard set of tests.
675    
676    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
677        reference to a subpattern the other side of a comment that contains an
678        opening parenthesis caused either an internal compiling error, or a
679        reference to the wrong subpattern.
680    
681    
682    Version 8.02 19-Mar-2010
683    ------------------------
684    
685    1.  The Unicode data tables have been updated to Unicode 5.2.0.
686    
687    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
688        configured.
689    
690    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
691        original author of that file, following a query about its status.
692    
693    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
694        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
695    
696    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
697        quantifier applied to a forward-referencing subroutine call, could compile
698        incorrect code or give the error "internal error: previously-checked
699        referenced subpattern not found".
700    
701    6.  Both MS Visual Studio and Symbian OS have problems with initializing
702        variables to point to external functions. For these systems, therefore,
703        pcre_malloc etc. are now initialized to local functions that call the
704        relevant global functions.
705    
706    7.  There were two entries missing in the vectors called coptable and poptable
707        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
708        I've fixed the data, and added a kludgy way of testing at compile time that
709        the lengths are correct (equal to the number of opcodes).
710    
711    8.  Following on from 7, I added a similar kludge to check the length of the
712        eint vector in pcreposix.c.
713    
714    9.  Error texts for pcre_compile() are held as one long string to avoid too
715        much relocation at load time. To find a text, the string is searched,
716        counting zeros. There was no check for running off the end of the string,
717        which could happen if a new error number was added without updating the
718        string.
719    
720    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
721    
722    11. \K was not working if it appeared in an atomic group or in a group that
723        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
724        \K is "not well defined" if used in an assertion. PCRE now accepts it if
725        the assertion is positive, but not if it is negative.
726    
727    12. Change 11 fortuitously reduced the size of the stack frame used in the
728        "match()" function of pcre_exec.c by one pointer. Forthcoming
729        implementation of support for (*MARK) will need an extra pointer on the
730        stack; I have reserved it now, so that the stack frame size does not
731        decrease.
732    
733    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
734        item in branch that calls a recursion is a subroutine call - as in the
735        second branch in the above example - was incorrectly given the compile-
736        time error "recursive call could loop indefinitely" because pcre_compile()
737        was not correctly checking the subroutine for matching a non-empty string.
738    
739    14. The checks for overrunning compiling workspace could trigger after an
740        overrun had occurred. This is a "should never occur" error, but it can be
741        triggered by pathological patterns such as hundreds of nested parentheses.
742        The checks now trigger 100 bytes before the end of the workspace.
743    
744    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
745    
746    
747    Version 8.01 19-Jan-2010
748    ------------------------
749    
750    1.  If a pattern contained a conditional subpattern with only one branch (in
751        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
752        computed the wrong minimum data length (which is of course zero for such
753        subpatterns). This could cause incorrect "no match" results.
754    
755    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
756        the pattern is reset in the first branch, pcre_compile() failed with
757        "internal error: code overflow at offset...". This happened only when
758        the reset was to the original external option setting. (An optimization
759        abstracts leading options settings into an external setting, which was the
760        cause of this.)
761    
762    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
763        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
764        assertion pattern did not match (meaning that the assertion was true), it
765        was incorrectly treated as false if the SKIP had been reached during the
766        matching. This also applied to assertions used as conditions.
767    
768    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
769        assertion subpattern, including such a pattern used as a condition,
770        unpredictable results occurred, instead of the error return
771        PCRE_ERROR_DFA_UITEM.
772    
773    5.  The C++ GlobalReplace function was not working like Perl for the special
774        situation when an empty string is matched. It now does the fancy magic
775        stuff that is necessary.
776    
777    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
778        removed. (These were left over from very, very early versions of PCRE.)
779    
780    7.  Some cosmetic changes to the code to make life easier when compiling it
781        as part of something else:
782    
783        (a) Change DEBUG to PCRE_DEBUG.
784    
785        (b) In pcre_compile(), rename the member of the "branch_chain" structure
786            called "current" as "current_branch", to prevent a collision with the
787            Linux macro when compiled as a kernel module.
788    
789        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
790            prevent a collision with the Linux macro when compiled as a kernel
791            module.
792    
793    8.  In pcre_compile() there are some checks for integer overflows that used to
794        cast potentially large values to (double). This has been changed to that
795        when building, a check for int64_t is made, and if it is found, it is used
796        instead, thus avoiding the use of floating point arithmetic. (There is no
797        other use of FP in PCRE.) If int64_t is not found, the fallback is to
798        double.
799    
800    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
801        2005 (difference between two addresses compared to an unsigned value).
802    
803    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
804        custom one, because of the following reported problem in Windows:
805    
806          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
807              under Win32.
808          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
809              therefore missing the function definition.
810          - The compiler thus generates a "C" signature for the test function.
811          - The linker fails to find the "C" function.
812          - PCRE fails to configure if asked to do so against libbz2.
813    
814    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
815        messages were output:
816    
817          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
818          rerunning libtoolize, to keep the correct libtool macros in-tree.
819          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
820    
821        I have done both of these things.
822    
823    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
824        most of the time, it *can* run out if it is given a pattern that contains a
825        runaway infinite recursion. I updated the discussion in the pcrestack man
826        page.
827    
828    13. Now that we have gone to the x.xx style of version numbers, the minor
829        version may start with zero. Using 08 or 09 is a bad idea because users
830        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
831        interpreted as invalid octal numbers. I've updated the previous comment in
832        configure.ac, and also added a check that gives an error if 08 or 09 are
833        used.
834    
835    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
836        causing partial matching to fail when the end of the subject matched \W
837        in a UTF-8 pattern where \W was quantified with a minimum of 3.
838    
839    15. There were some discrepancies between the declarations in pcre_internal.h
840        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
841        their definitions. The declarations used "const uschar *" and the
842        definitions used USPTR. Even though USPTR is normally defined as "const
843        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
844        reported that: "This difference in casting confuses some C++ compilers, for
845        example, SunCC recognizes above declarations as different functions and
846        generates broken code for hbpcre." I have changed the declarations to use
847        USPTR.
848    
849    16. GNU libtool is named differently on some systems. The autogen.sh script now
850        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
851        (FreeBSD).
852    
853    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
854        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
855        comment: "Figure out how to create a longlong from a string: strtoll and
856        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
857        instance, but it only takes 2 args instead of 3!"
858    
859    18. A subtle bug concerned with back references has been fixed by a change of
860        specification, with a corresponding code fix. A pattern such as
861        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
862        refers, was giving matches when it shouldn't. For example, xa=xaaa would
863        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
864        same bug. Such groups have to be quantified to be useful, or contained
865        inside another quantified group. (If there's no repetition, the reference
866        can never match.) The problem arises because, having left the group and
867        moved on to the rest of the pattern, a later failure that backtracks into
868        the group uses the captured value from the final iteration of the group
869        rather than the correct earlier one. I have fixed this in PCRE by forcing
870        any group that contains a reference to itself to be an atomic group; that
871        is, there cannot be any backtracking into it once it has completed. This is
872        similar to recursive and subroutine calls.
873    
874    
875    Version 8.00 19-Oct-09
876    ----------------------
877    
878    1.  The table for translating pcre_compile() error codes into POSIX error codes
879        was out-of-date, and there was no check on the pcre_compile() error code
880        being within the table. This could lead to an OK return being given in
881        error.
882    
883    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
884        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
885        in a Windows environment.
886    
887    3.  The pcregrep --count option prints the count for each file even when it is
888        zero, as does GNU grep. However, pcregrep was also printing all files when
889        --files-with-matches was added. Now, when both options are given, it prints
890        counts only for those files that have at least one match. (GNU grep just
891        prints the file name in this circumstance, but including the count seems
892        more useful - otherwise, why use --count?) Also ensured that the
893        combination -clh just lists non-zero counts, with no names.
894    
895    4.  The long form of the pcregrep -F option was incorrectly implemented as
896        --fixed_strings instead of --fixed-strings. This is an incompatible change,
897        but it seems right to fix it, and I didn't think it was worth preserving
898        the old behaviour.
899    
900    5.  The command line items --regex=pattern and --regexp=pattern were not
901        recognized by pcregrep, which required --regex pattern or --regexp pattern
902        (with a space rather than an '='). The man page documented the '=' forms,
903        which are compatible with GNU grep; these now work.
904    
905    6.  No libpcreposix.pc file was created for pkg-config; there was just
906        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
907    
908    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
909        when UCP support is not needed, by modifying the Python script that
910        generates it from Unicode data files. This should not matter if the module
911        is correctly used as a library, but I received one complaint about 50K of
912        unwanted data. My guess is that the person linked everything into his
913        program rather than using a library. Anyway, it does no harm.
914    
915    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
916        was a minimum greater than 1 for a wide character in a possessive
917        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
918        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
919        character. Chaos in the form of incorrect output or a compiling loop could
920        result.
921    
922    9.  The restrictions on what a pattern can contain when partial matching is
923        requested for pcre_exec() have been removed. All patterns can now be
924        partially matched by this function. In addition, if there are at least two
925        slots in the offset vector, the offset of the earliest inspected character
926        for the match and the offset of the end of the subject are set in them when
927        PCRE_ERROR_PARTIAL is returned.
928    
929    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
930        synonymous with PCRE_PARTIAL, for backwards compatibility, and
931        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
932        and may be more useful for multi-segment matching.
933    
934    11. Partial matching with pcre_exec() is now more intuitive. A partial match
935        used to be given if ever the end of the subject was reached; now it is
936        given only if matching could not proceed because another character was
937        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
938        string "Z", which now yields "no match" instead of "partial match". In the
939        case of pcre_dfa_exec(), "no match" is given if every matching path for the
940        final character ended with (*FAIL).
941    
942    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
943        if the pattern had a "must contain" character that was already found in the
944        earlier partial match, unless partial matching was again requested. For
945        example, with the pattern /dog.(body)?/, the "must contain" character is
946        "g". If the first part-match was for the string "dog", restarting with
947        "sbody" failed. This bug has been fixed.
948    
949    13. The string returned by pcre_dfa_exec() after a partial match has been
950        changed so that it starts at the first inspected character rather than the
951        first character of the match. This makes a difference only if the pattern
952        starts with a lookbehind assertion or \b or \B (\K is not supported by
953        pcre_dfa_exec()). It's an incompatible change, but it makes the two
954        matching functions compatible, and I think it's the right thing to do.
955    
956    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
957        so that the demonstration program is easily available in environments where
958        PCRE has not been installed from source.
959    
960    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
961        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
962        library.
963    
964    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
965        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
966        is not the first non-POSIX option to be added. Clearly some people find
967        these options useful.
968    
969    17. If a caller to the POSIX matching function regexec() passes a non-zero
970        value for nmatch with a NULL value for pmatch, the value of
971        nmatch is forced to zero.
972    
973    18. RunGrepTest did not have a test for the availability of the -u option of
974        the diff command, as RunTest does. It now checks in the same way as
975        RunTest, and also checks for the -b option.
976    
977    19. If an odd number of negated classes containing just a single character
978        interposed, within parentheses, between a forward reference to a named
979        subpattern and the definition of the subpattern, compilation crashed with
980        an internal error, complaining that it could not find the referenced
981        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
982        [The bug was that it was starting one character too far in when skipping
983        over the character class, thus treating the ] as data rather than
984        terminating the class. This meant it could skip too much.]
985    
986    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
987        /g option in pcretest when the pattern contains \K, which makes it possible
988        to have an empty string match not at the start, even when the pattern is
989        anchored. Updated pcretest and pcredemo to use this option.
990    
991    21. If the maximum number of capturing subpatterns in a recursion was greater
992        than the maximum at the outer level, the higher number was returned, but
993        with unset values at the outer level. The correct (outer level) value is
994        now given.
995    
996    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
997        PCRE did not set those parentheses (unlike Perl). I have now found a way to
998        make it do so. The string so far is captured, making this feature
999        compatible with Perl.
1000    
1001    23. The tests have been re-organized, adding tests 11 and 12, to make it
1002        possible to check the Perl 5.10 features against Perl 5.10.
1003    
1004    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1005        pattern matches a fixed length string. PCRE did not allow this; now it
1006        does. Neither allows recursion.
1007    
1008    25. I finally figured out how to implement a request to provide the minimum
1009        length of subject string that was needed in order to match a given pattern.
1010        (It was back references and recursion that I had previously got hung up
1011        on.) This code has now been added to pcre_study(); it finds a lower bound
1012        to the length of subject needed. It is not necessarily the greatest lower
1013        bound, but using it to avoid searching strings that are too short does give
1014        some useful speed-ups. The value is available to calling programs via
1015        pcre_fullinfo().
1016    
1017    26. While implementing 25, I discovered to my embarrassment that pcretest had
1018        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1019        study optimizations had never been tested with that matching function.
1020        Oops. What is worse, even when it was passed study data, there was a bug in
1021        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1022        were also very few tests of studied patterns with pcre_dfa_exec().
1023    
1024    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1025        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1026        on the other side of the coin, they are no longer allowed to have different
1027        names, because these cannot be distinguished in PCRE, and this has caused
1028        confusion. (This is a difference from Perl.)
1029    
1030    28. When duplicate subpattern names are present (necessarily with different
1031        numbers, as required by 27 above), and a test is made by name in a
1032        conditional pattern, either for a subpattern having been matched, or for
1033        recursion in such a pattern, all the associated numbered subpatterns are
1034        tested, and the overall condition is true if the condition is true for any
1035        one of them. This is the way Perl works, and is also more like the way
1036        testing by number works.
1037    
1038    
1039    Version 7.9 11-Apr-09
1040    ---------------------
1041    
1042    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1043        (pcretest), all targets were linked against these libraries. This included
1044        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1045        libraries. This caused unwanted dependencies to be created. This problem
1046        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1047        pcretest is linked with readline.
1048    
1049    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1050        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1051        moved outside it again, because FALSE and TRUE are already defined in AIX,
1052        but BOOL is not.
1053    
1054    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1055        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1056    
1057    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1058        hyphens) following file names and line numbers when outputting matching
1059        lines. This is not true; no spaces are inserted. I have also clarified the
1060        wording for the --colour (or --color) option.
1061    
1062    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1063        was not coloured; this is different to GNU grep, so I have changed it to be
1064        the same.
1065    
1066    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1067        each matching line was coloured. Now it goes on to look for further matches
1068        of any of the test patterns, which is the same behaviour as GNU grep.
1069    
1070    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1071        doesn't make sense to accept an empty string match in pcregrep, so I have
1072        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1073        seems to be how GNU grep behaves.
1074    
1075    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1076        start or after a newline", because the conditional assertion was not being
1077        correctly handled. The rule now is that both the assertion and what follows
1078        in the first alternative must satisfy the test.
1079    
1080    9.  If auto-callout was enabled in a pattern with a conditional group whose
1081        condition was an assertion, PCRE could crash during matching, both with
1082        pcre_exec() and pcre_dfa_exec().
1083    
1084    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1085        used for matching.
1086    
1087    11. Unicode property support in character classes was not working for
1088        characters (bytes) greater than 127 when not in UTF-8 mode.
1089    
1090    12. Added the -M command line option to pcretest.
1091    
1092    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1093    
1094    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1095    
1096    16. Added comments and documentation about mis-use of no_arg in the C++
1097        wrapper.
1098    
1099    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1100        from Martin Jerabek that uses macro names for all relevant character and
1101        string constants.
1102    
1103    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1104        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1105        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1106        these, but not everybody uses configure.
1107    
1108    19. A conditional group that had only one branch was not being correctly
1109        recognized as an item that could match an empty string. This meant that an
1110        enclosing group might also not be so recognized, causing infinite looping
1111        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1112        with the subject "ab", where knowledge that the repeated group can match
1113        nothing is needed in order to break the loop.
1114    
1115    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1116        exec(), but without supplying a callout function, matching went wrong.
1117    
1118    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1119        leak if the size of the offset vector was greater than 30. When the vector
1120        is smaller, the saved offsets during recursion go onto a local stack
1121        vector, but for larger vectors malloc() is used. It was failing to free
1122        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1123        error, in fact).
1124    
1125    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1126        heapframe that is used only when UTF-8 support is enabled. This caused no
1127        problem, but was untidy.
1128    
1129    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1130        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1131        included within another project.
1132    
1133    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1134        slightly modified by me:
1135    
1136          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1137              not building pcregrep.
1138    
1139          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1140              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1141    
1142    25. Forward references, both numeric and by name, in patterns that made use of
1143        duplicate group numbers, could behave incorrectly or give incorrect errors,
1144        because when scanning forward to find the reference group, PCRE was not
1145        taking into account the duplicate group numbers. A pattern such as
1146        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1147    
1148    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1149        the feature of a custom pointer more persuasive (as requested by a user).
1150    
1151    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1152        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1153        pre-defined.
1154    
1155    28. Added support for (*UTF8) at the start of a pattern.
1156    
1157    29. Arrange for flags added by the "release type" setting in CMake to be shown
1158        in the configuration summary.
1159    
1160    
1161    Version 7.8 05-Sep-08
1162    ---------------------
1163    
1164    1.  Replaced UCP searching code with optimized version as implemented for Ad
1165        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1166        stage table and inline lookup instead of a function, giving speed ups of 2
1167        to 5 times on some simple patterns that I tested. Permission was given to
1168        distribute the MultiStage2.py script that generates the tables (it's not in
1169        the tarball, but is in the Subversion repository).
1170    
1171    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1172        scripts.
1173    
1174    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1175        a group with a zero qualifier. The result of the study could be incorrect,
1176        or the function might crash, depending on the pattern.
1177    
1178    4.  Caseless matching was not working for non-ASCII characters in back
1179        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1180        It now works when Unicode Property Support is available.
1181    
1182    5.  In pcretest, an escape such as \x{de} in the data was always generating
1183        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1184        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1185        truncation.
1186    
1187    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1188    
1189    7.  Added two (int) casts to pcregrep when printing the difference of two
1190        pointers, in case they are 64-bit values.
1191    
1192    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1193        test 2 if it fails.
1194    
1195    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1196        and a #define of that name to empty if it is not externally set. This is to
1197        allow users of MSVC to set it if necessary.
1198    
1199    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1200        the convenience functions in the pcre_get.c source file.
1201    
1202    11. An option change at the start of a pattern that had top-level alternatives
1203        could cause overwriting and/or a crash. This command provoked a crash in
1204        some environments:
1205    
1206          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1207    
1208        This potential security problem was recorded as CVE-2008-2371.
1209    
1210    12. For a pattern where the match had to start at the beginning or immediately
1211        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1212        pcre_dfa_exec() could read past the end of the passed subject if there was
1213        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1214        pcretest so that it places the subject at the end of its malloc-ed buffer.
1215    
1216    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1217        exec() might read past the end of the data buffer in UTF-8 mode.
1218    
1219    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1220        the data contained the byte 0x85 as part of a UTF-8 character within its
1221        first line. This applied both to normal and DFA matching.
1222    
1223    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1224        /^[^d]*?$/8 failed to match "abc".
1225    
1226    16. Added a missing copyright notice to pcrecpp_internal.h.
1227    
1228    17. Make it more clear in the documentation that values returned from
1229        pcre_exec() in ovector are byte offsets, not character counts.
1230    
1231    18. Tidied a few places to stop certain compilers from issuing warnings.
1232    
1233    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1234        supplied by Stefan Weber. I made a further small update for 7.8 because
1235        there is a change of source arrangements: the pcre_searchfuncs.c module is
1236        replaced by pcre_ucd.c.
1237    
1238    
1239    Version 7.7 07-May-08
1240    ---------------------
1241    
1242    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1243        a string to a long long, pretend we don't even have a long long." This is
1244        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1245    
1246    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1247        pre-7.6 versions, which defined a global no_arg variable instead of putting
1248        it in the RE class. (See also #8 below.)
1249    
1250    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1251        Lopes.
1252    
1253    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1254    
1255        (1) The include/exclude patterns were being applied to the whole pathnames
1256            of files, instead of just to the final components.
1257    
1258        (2) If there was more than one level of directory, the subdirectories were
1259            skipped unless they satisfied the include/exclude conditions. This is
1260            inconsistent with GNU grep (and could even be seen as contrary to the
1261            pcregrep specification - which I improved to make it absolutely clear).
1262            The action now is always to scan all levels of directory, and just
1263            apply the include/exclude patterns to regular files.
1264    
1265    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1266        --exclude_dir in the tests to avoid scanning .svn directories.
1267    
1268    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1269        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1270        doesn't support NULs in patterns.
1271    
1272    7.  Added some missing "const"s to declarations of static tables in
1273        pcre_compile.c and pcre_dfa_exec.c.
1274    
1275    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1276        caused by fix #2  above. (Subsequently also a second patch to fix the
1277        first patch. And a third patch - this was a messy problem.)
1278    
1279    9.  Applied Craig's patch to remove the use of push_back().
1280    
1281    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1282        matching function regexec().
1283    
1284    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1285        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1286        references. PCRE supports relative numbers with this syntax (I don't think
1287        Oniguruma does).
1288    
1289    12. Previously, a group with a zero repeat such as (...){0} was completely
1290        omitted from the compiled regex. However, this means that if the group
1291        was called as a subroutine from elsewhere in the pattern, things went wrong
1292        (an internal error was given). Such groups are now left in the compiled
1293        pattern, with a new opcode that causes them to be skipped at execution
1294        time.
1295    
1296    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1297        to the way PCRE behaves:
1298    
1299        (a) A lone ] character is dis-allowed (Perl treats it as data).
1300    
1301        (b) A back reference to an unmatched subpattern matches an empty string
1302            (Perl fails the current match path).
1303    
1304        (c) A data ] in a character class must be notated as \] because if the
1305            first data character in a class is ], it defines an empty class. (In
1306            Perl it is not possible to have an empty class.) The empty class []
1307            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1308            The negative empty class [^] matches any one character, independently
1309            of the DOTALL setting.
1310    
1311    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1312        non-existent subpattern following a character class starting with ']' and
1313        containing () gave an internal compiling error instead of "reference to
1314        non-existent subpattern". Fortunately, when the pattern did exist, the
1315        compiled code was correct. (When scanning forwards to check for the
1316        existencd of the subpattern, it was treating the data ']' as terminating
1317        the class, so got the count wrong. When actually compiling, the reference
1318        was subsequently set up correctly.)
1319    
1320    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1321        it was being rejected as not supported by pcre_dfa_exec(), even though
1322        other assertions are supported. I have made pcre_dfa_exec() support
1323        (*FAIL).
1324    
1325    16. The implementation of 13c above involved the invention of a new opcode,
1326        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1327        cannot be changed at match time, I realized I could make a small
1328        improvement to matching performance by compiling OP_ALLANY instead of
1329        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1330        on the OP_ANY path.
1331    
1332    17. Compiling pcretest on Windows with readline support failed without the
1333        following two fixes: (1) Make the unistd.h include conditional on
1334        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1335    
1336    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1337        ncurses library to be included for pcretest when ReadLine support is
1338        requested, but also to allow for it to be overridden. This patch came from
1339        Daniel Bergström.
1340    
1341    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1342        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1343        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1344        spotting this.
1345    
1346    
1347    Version 7.6 28-Jan-08
1348    ---------------------
1349    
1350    1.  A character class containing a very large number of characters with
1351        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1352        overflow.
1353    
1354    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1355        HAVE_LONG_LONG is not defined.
1356    
1357    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1358        bring them up to date and include new features. This patch includes:
1359    
1360        - Fixed PH's badly added libz and libbz2 support.
1361        - Fixed a problem with static linking.
1362        - Added pcredemo. [But later removed - see 7 below.]
1363        - Fixed dftables problem and added an option.
1364        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1365            HAVE_LONG_LONG.
1366        - Added readline support for pcretest.
1367        - Added an listing of the option settings after cmake has run.
1368    
1369    4.  A user submitted a patch to Makefile that makes it easy to create
1370        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1371        Makefile.am that cause it to include this special target, without
1372        affecting anything else. Note that the same mingw target plus all
1373        the other distribution libraries and programs are now supported
1374        when configuring with CMake (see 6 below) instead of with
1375        Configure/Make.
1376    
1377    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1378        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1379        exported in the Windows port". It has not yet been confirmed that the patch
1380        solves the problem, but it does no harm.
1381    
1382    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1383        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1384        with CMake, and also correct the comment about stack recursion.
1385    
1386    7.  Remove the automatic building of pcredemo from the ./configure system and
1387        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1388        of a program that users should build themselves after PCRE is installed, so
1389        building it automatically is not really right. What is more, it gave
1390        trouble in some build environments.
1391    
1392    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1393    
1394    
1395    Version 7.5 10-Jan-08
1396  ---------------------  ---------------------
1397    
1398  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1399      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1400    
1401  2.  Negative specials like \S did not work in character classes in UTF-8 mode.  2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1402      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1403      included.      included.
1404    
1405  3.  The same bug as (2) above applied to negated POSIX classes such as  3.  The same bug as (2) above applied to negated POSIX classes such as
1406      [:^space:].      [:^space:].
1407    
1408  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1409      defined or documented. It seems to have been a typo for PCRE_STATIC, so      defined or documented. It seems to have been a typo for PCRE_STATIC, so
1410      I have changed it.      I have changed it.
1411    
1412  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1413      first named subpattern) and a construct such as (?&a) would reference the      first named subpattern) and a construct such as (?&a) would reference the
1414      first named subpattern whose name started with "a" (in other words, the      first named subpattern whose name started with "a" (in other words, the
1415      length check was missing). Both these problems are fixed. "Subpattern name      length check was missing). Both these problems are fixed. "Subpattern name
1416      expected" is now given for (?&) (a zero-length name), and this patch also      expected" is now given for (?&) (a zero-length name), and this patch also
1417      makes it give the same error for \k'' (previously it complained that that      makes it give the same error for \k'' (previously it complained that that
1418      was a reference to a non-existent subpattern).      was a reference to a non-existent subpattern).
1419    
1420  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1421      this is right because (?- can be followed by option settings as well as by      this is right because (?- can be followed by option settings as well as by
1422      digits. I have, however, made the messages clearer.      digits. I have, however, made the messages clearer.
1423    
1424  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1425      than the number used in the conditional) now cause a compile-time error.      than the number used in the conditional) now cause a compile-time error.
1426      This is actually not compatible with Perl, which accepts such patterns, but      This is actually not compatible with Perl, which accepts such patterns, but
1427      treats the conditional as always being FALSE (as PCRE used to), but it      treats the conditional as always being FALSE (as PCRE used to), but it
1428      seems to me that giving a diagnostic is better.      seems to me that giving a diagnostic is better.
1429    
1430  8.  Change "alphameric" to the more common word "alphanumeric" in comments  8.  Change "alphameric" to the more common word "alphanumeric" in comments
1431      and messages.      and messages.
1432    
1433  9.  Fix two occurrences of "backslash" in comments that should have been  9.  Fix two occurrences of "backslash" in comments that should have been
1434      "backspace".      "backspace".
1435    
1436  10. Remove two redundant lines of code that can never be obeyed (their function  10. Remove two redundant lines of code that can never be obeyed (their function
1437      was moved elsewhere).      was moved elsewhere).
1438    
1439  11. The program that makes PCRE's Unicode character property table had a bug  11. The program that makes PCRE's Unicode character property table had a bug
1440      which caused it to generate incorrect table entries for sequences of      which caused it to generate incorrect table entries for sequences of
1441      characters that have the same character type, but are in different scripts.      characters that have the same character type, but are in different scripts.
1442      It amalgamated them into a single range, with the script of the first of      It amalgamated them into a single range, with the script of the first of
1443      them. In other words, some characters were in the wrong script. There were      them. In other words, some characters were in the wrong script. There were
1444      thirteen such cases, affecting characters in the following ranges:      thirteen such cases, affecting characters in the following ranges:
1445    
1446        U+002b0 - U+002c1        U+002b0 - U+002c1
1447        U+0060c - U+0060d        U+0060c - U+0060d
1448        U+0061e - U+00612        U+0061e - U+00612
1449        U+0064b - U+0065e        U+0064b - U+0065e
1450        U+0074d - U+0076d        U+0074d - U+0076d
1451        U+01800 - U+01805        U+01800 - U+01805
# Line 65  Version 7.5 12-Nov-07 Line 1456  Version 7.5 12-Nov-07
1456        U+03260 - U+0327f        U+03260 - U+0327f
1457        U+0fb46 - U+0fbb1        U+0fb46 - U+0fbb1
1458        U+10450 - U+1049d        U+10450 - U+1049d
1459    
1460  12. The -o option (show only the matching part of a line) for pcregrep was not  12. The -o option (show only the matching part of a line) for pcregrep was not
1461      compatible with GNU grep in that, if there was more than one match in a      compatible with GNU grep in that, if there was more than one match in a
1462      line, it showed only the first of them. It now behaves in the same way as      line, it showed only the first of them. It now behaves in the same way as
1463      GNU grep.      GNU grep.
1464    
1465  13. If the -o and -v options were combined for pcregrep, it printed a blank  13. If the -o and -v options were combined for pcregrep, it printed a blank
1466      line for every non-matching line. GNU grep prints nothing, and pcregrep now      line for every non-matching line. GNU grep prints nothing, and pcregrep now
1467      does the same. The return code can be used to tell if there were any      does the same. The return code can be used to tell if there were any
1468      non-matching lines.      non-matching lines.
1469    
1470    14. Added --file-offsets and --line-offsets to pcregrep.
1471    
1472    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1473        infinitely looping recursion. The bug was that positive lookaheads were not
1474        being skipped when checking for a possible empty match (negative lookaheads
1475        and both kinds of lookbehind were skipped).
1476    
1477    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1478        inclusion of <windows.h> to before rather than after the definition of
1479        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1480    
1481    17. Specifying a possessive quantifier with a specific limit for a Unicode
1482        character property caused pcre_compile() to compile bad code, which led at
1483        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1484        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1485        caused the error; without that there was no problem.
1486    
1487    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1488    
1489    19. Added --enable-pcretest-libreadline.
1490    
1491    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1492        RE::GlobalReplace(). As a result, the number of replacements returned was
1493        double what it should be. I removed one of the increments, but Craig sent a
1494        later patch that removed the other one (the right fix) and added unit tests
1495        that check the return values (which was not done before).
1496    
1497    21. Several CMake things:
1498    
1499        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1500            the names libpcre and libpcreposix, not just pcre and pcreposix.
1501    
1502        (2) The above change means that pcretest and pcregrep are now correctly
1503            linked with the newly-built libraries, not previously installed ones.
1504    
1505        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1506    
1507    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1508        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1509        UTF-8 newline character). The key issue is that the pattern starts .*;
1510        this means that the match must be either at the beginning, or after a
1511        newline. The bug was in the code for advancing after a failed match and
1512        checking that the new position followed a newline. It was not taking
1513        account of UTF-8 characters correctly.
1514    
1515    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1516        character classes. PCRE was not treating the sequence [:...:] as a
1517        character class unless the ... were all letters. Perl, however, seems to
1518        allow any characters between [: and :], though of course it rejects as
1519        unknown any "names" that contain non-letters, because all the known class
1520        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1521        for example, whereas PCRE did not - it did not recognize a POSIX character
1522        class. This seemed a bit dangerous, so the code has been changed to be
1523        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1524        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1525        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1526        Perl does, and where it didn't before.
1527    
1528    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1529        Windows environments %n is disabled by default.
1530    
1531    
1532  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07

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