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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.5 12-Nov-07  Version 8.22
5    ------------
6    
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
9    
10    2.  Fixed a bug in the code for calculating the fixed length of lookbehind
11        assertions.
12    
13    3.  Removed the function pcre_info(), which has been obsolete and deprecated
14        since it was replaced by pcre_fullinfo() in February 2000.
15    
16    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
17        match a (*MARK), and the match failed at the start of the subject, a
18        reference to memory before the start of the subject could occur. This bug
19        was introduced by fix 17 of release 8.21.
20    
21    
22    Version 8.21 12-Dec-2011
23    ------------------------
24    
25    1.  Updating the JIT compiler.
26    
27    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
28        are added as well.
29    
30    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
31        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
32        calling _pcre_jit_exec. Some extra comments are added.
33    
34    4.  (*MARK) settings inside atomic groups that do not contain any capturing
35        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
36        was introduced by change 18 for 8.20.
37    
38    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
39        ECMA-262 standard.
40    
41    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
42        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
43        This bug was probably introduced by change 9 of 8.13.
44    
45    7.  While fixing 6 above, I noticed that a number of other items were being
46        incorrectly rejected as "not fixed length". This arose partly because newer
47        opcodes had not been added to the fixed-length checking code. I have (a)
48        corrected the bug and added tests for these items, and (b) arranged for an
49        error to occur if an unknown opcode is encountered while checking for fixed
50        length instead of just assuming "not fixed length". The items that were
51        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
52        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
53        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
54    
55    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
56        being incorrectly compiled and would have given unpredicatble results.
57    
58    9.  A possessively repeated subpattern with minimum repeat count greater than
59        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
60        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
61        the first (A) could occur when it should not.
62    
63    10. Add a cast and remove a redundant test from the code.
64    
65    11. JIT should use pcre_malloc/pcre_free for allocation.
66    
67    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
68        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
69        is anything other than /usr, -L is still shown).
70    
71    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
72    
73    14. Perl does not support \N without a following name in a [] class; PCRE now
74        also gives an error.
75    
76    15. If a forward reference was repeated with an upper limit of around 2000,
77        it caused the error "internal error: overran compiling workspace". The
78        maximum number of forward references (including repeats) was limited by the
79        internal workspace, and dependent on the LINK_SIZE. The code has been
80        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
81        the default depends on LINK_SIZE. There is a new upper limit (for safety)
82        of around 200,000 forward references. While doing this, I also speeded up
83        the filling in of repeated forward references.
84    
85    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
86        incorrectly expecting the subject to contain another "a" after the start.
87    
88    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
89        in the match, the SKIP should be ignored. This was not happening; instead
90        the SKIP was being treated as NOMATCH. For patterns such as
91        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
92        tested.
93    
94    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
95        now much more compatible with Perl, in particular in cases where the result
96        is a non-match for a non-anchored pattern. For example, if
97        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
98        "m", where previously it did not return a name. A side effect of this
99        change is that for partial matches, the last encountered mark name is
100        returned, as for non matches. A number of tests that were previously not
101        Perl-compatible have been moved into the Perl-compatible test files. The
102        refactoring has had the pleasing side effect of removing one argument from
103        the match() function, thus reducing its stack requirements.
104    
105    19. If the /S+ option was used in pcretest to study a pattern using JIT,
106        subsequent uses of /S (without +) incorrectly behaved like /S+.
107    
108    21. Retrieve executable code size support for the JIT compiler and fixing
109        some warnings.
110    
111    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
112        not work when the shorter character appeared right at the end of the
113        subject string.
114    
115    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
116        systems.
117    
118    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
119        output it when the /M option is used in pcretest.
120    
121    25. The CheckMan script was not being included in the distribution. Also, added
122        an explicit "perl" to run Perl scripts from the PrepareRelease script
123        because this is reportedly needed in Windows.
124    
125    26. If study data was being save in a file and studying had not found a set of
126        "starts with" bytes for the pattern, the data written to the file (though
127        never used) was taken from uninitialized memory and so caused valgrind to
128        complain.
129    
130    27. Updated RunTest.bat as provided by Sheri Pierce.
131    
132    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
133    
134    29. Computation of memory usage for the table of capturing group names was
135        giving an unnecessarily large value.
136    
137    
138    Version 8.20 21-Oct-2011
139    ------------------------
140    
141    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
142        a POSIX class. After further experiments with Perl, which convinced me that
143        Perl has bugs and confusions, a closing square bracket is no longer allowed
144        in a POSIX name. This bug also affected patterns with classes that started
145        with full stops.
146    
147    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
148        captured substring, but while checking the failing first alternative,
149        substring 1 is temporarily captured. If the output vector supplied to
150        pcre_exec() was not big enough for this capture, the yield of the function
151        was still zero ("insufficient space for captured substrings"). This cannot
152        be totally fixed without adding another stack variable, which seems a lot
153        of expense for a edge case. However, I have improved the situation in cases
154        such as /(a)(b)x|abc/ matched against "abc", where the return code
155        indicates that fewer than the maximum number of slots in the ovector have
156        been set.
157    
158    3.  Related to (2) above: when there are more back references in a pattern than
159        slots in the output vector, pcre_exec() uses temporary memory during
160        matching, and copies in the captures as far as possible afterwards. It was
161        using the entire output vector, but this conflicts with the specification
162        that only 2/3 is used for passing back captured substrings. Now it uses
163        only the first 2/3, for compatibility. This is, of course, another edge
164        case.
165    
166    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
167        main code base, and can be used by building with --enable-jit. When this is
168        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
169        runtime --no-jit option is given.
170    
171    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
172        ovector, the return from the function was zero, implying that there were
173        other matches that did not fit. The correct "exactly full" value is now
174        returned.
175    
176    6.  If a subpattern that was called recursively or as a subroutine contained
177        (*PRUNE) or any other control that caused it to give a non-standard return,
178        invalid errors such as "Error -26 (nested recursion at the same subject
179        position)" or even infinite loops could occur.
180    
181    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
182        computing the minimum length on reaching *ACCEPT, and so ended up with the
183        wrong value of 1 rather than 0. Further investigation indicates that
184        computing a minimum subject length in the presence of *ACCEPT is difficult
185        (think back references, subroutine calls), and so I have changed the code
186        so that no minimum is registered for a pattern that contains *ACCEPT.
187    
188    8.  If (*THEN) was present in the first (true) branch of a conditional group,
189        it was not handled as intended. [But see 16 below.]
190    
191    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
192        Sheri Pierce.
193    
194    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
195        the first byte in a match must be "a".
196    
197    11. Change 17 for 8.13 increased the recursion depth for patterns like
198        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
199        pattern contains any instances of (*THEN). If it does not, the old
200        optimizations are restored. It would be nice to do this on a per-group
201        basis, but at the moment that is not feasible.
202    
203    12. In some environments, the output of pcretest -C is CRLF terminated. This
204        broke RunTest's code that checks for the link size. A single white space
205        character after the value is now allowed for.
206    
207    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
208        For "fr", it uses the Windows-specific input and output files.
209    
210    14. If (*THEN) appeared in a group that was called recursively or as a
211        subroutine, it did not work as intended. [But see next item.]
212    
213    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
214        pattern fragments (but not containing any | characters). If A and B are
215        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
216        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
217        D. In other words, Perl considers parentheses that do not contain any |
218        characters to be part of a surrounding alternative, whereas PCRE was
219        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
220        differently. PCRE now behaves in the same way as Perl, except in the case
221        of subroutine/recursion calls such as (?1) which have in any case always
222        been different (but PCRE had them first :-).
223    
224    16. Related to 15 above: Perl does not treat the | in a conditional group as
225        creating alternatives. Such a group is treated in the same way as an
226        ordinary group without any | characters when processing (*THEN). PCRE has
227        been changed to match Perl's behaviour.
228    
229    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
230        RunGrepTest script failed.
231    
232    18. Change 22 for version 13 caused atomic groups to use more stack. This is
233        inevitable for groups that contain captures, but it can lead to a lot of
234        stack use in large patterns. The old behaviour has been restored for atomic
235        groups that do not contain any capturing parentheses.
236    
237    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
238        suppress the check for a minimum subject length at run time. (If it was
239        given to pcre_exec() or pcre_dfa_exec() it did work.)
240    
241    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
242        fail to work when decoding hex characters in data strings in EBCDIC
243        environments.
244    
245    21. It appears that in at least one Mac OS environment, the isxdigit() function
246        is implemented as a macro that evaluates to its argument more than once,
247        contravening the C 90 Standard (I haven't checked a later standard). There
248        was an instance in pcretest which caused it to go wrong when processing
249        \x{...} escapes in subject strings. The has been rewritten to avoid using
250        things like p++ in the argument of isxdigit().
251    
252    
253    Version 8.13 16-Aug-2011
254    ------------------------
255    
256    1.  The Unicode data tables have been updated to Unicode 6.0.0.
257    
258    2.  Two minor typos in pcre_internal.h have been fixed.
259    
260    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
261        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
262        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
263    
264    4.  There were a number of related bugs in the code for matching backrefences
265        caselessly in UTF-8 mode when codes for the characters concerned were
266        different numbers of bytes. For example, U+023A and U+2C65 are an upper
267        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
268        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
269        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
270        2-byte code at the end of the subject (it thought there wasn't enough data
271        left).
272    
273    5.  Comprehensive information about what went wrong is now returned by
274        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
275        as the output vector has at least 2 elements. The offset of the start of
276        the failing character and a reason code are placed in the vector.
277    
278    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
279        now returned is for the first byte of the failing character, instead of the
280        last byte inspected. This is an incompatible change, but I hope it is small
281        enough not to be a problem. It makes the returned offset consistent with
282        pcre_exec() and pcre_dfa_exec().
283    
284    7.  pcretest now gives a text phrase as well as the error number when
285        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
286        failure, the offset and reason code are output.
287    
288    8.  When \R was used with a maximizing quantifier it failed to skip backwards
289        over a \r\n pair if the subsequent match failed. Instead, it just skipped
290        back over a single character (\n). This seems wrong (because it treated the
291        two characters as a single entity when going forwards), conflicts with the
292        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
293        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
294        has been changed.
295    
296    9.  Some internal refactoring has changed the processing so that the handling
297        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
298        time (the PCRE_DOTALL option was changed this way some time ago: version
299        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
300        which was always a bit of a fudge. It also means that there is one less
301        argument for the match() function, which reduces its stack requirements
302        slightly. This change also fixes an incompatibility with Perl: the pattern
303        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
304    
305    10. More internal refactoring has drastically reduced the number of recursive
306        calls to match() for possessively repeated groups such as (abc)++ when
307        using pcre_exec().
308    
309    11. While implementing 10, a number of bugs in the handling of groups were
310        discovered and fixed:
311    
312        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
313        (a|)*(?1) gave a compile-time internal error.
314        ((a|)+)+  did not notice that the outer group could match an empty string.
315        (^a|^)+   was not marked as anchored.
316        (.*a|.*)+ was not marked as matching at start or after a newline.
317    
318    12. Yet more internal refactoring has removed another argument from the match()
319        function. Special calls to this function are now indicated by setting a
320        value in a variable in the "match data" data block.
321    
322    13. Be more explicit in pcre_study() instead of relying on "default" for
323        opcodes that mean there is no starting character; this means that when new
324        ones are added and accidentally left out of pcre_study(), testing should
325        pick them up.
326    
327    14. The -s option of pcretest has been documented for ages as being an old
328        synonym of -m (show memory usage). I have changed it to mean "force study
329        for every regex", that is, assume /S for every regex. This is similar to -i
330        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
331        using it. It makes it easier to run collections of tests with and without
332        study enabled, and thereby test pcre_study() more easily. All the standard
333        tests are now run with and without -s (but some patterns can be marked as
334        "never study" - see 20 below).
335    
336    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
337        restoration of the capturing data to the outer values was not happening
338        correctly.
339    
340    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
341        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
342        pattern had matched an empty string, and so incorrectly returned a no
343        match.
344    
345    17. There was optimizing code for the last branch of non-capturing parentheses,
346        and also for the obeyed branch of a conditional subexpression, which used
347        tail recursion to cut down on stack usage. Unfortunately, now that there is
348        the possibility of (*THEN) occurring in these branches, tail recursion is
349        no longer possible because the return has to be checked for (*THEN). These
350        two optimizations have therefore been removed. [But see 8.20/11 above.]
351    
352    18. If a pattern containing \R was studied, it was assumed that \R always
353        matched two bytes, thus causing the minimum subject length to be
354        incorrectly computed because \R can also match just one byte.
355    
356    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
357        was incorrectly computed.
358    
359    20. If /S is present twice on a test pattern in pcretest input, it now
360        *disables* studying, thereby overriding the use of -s on the command line
361        (see 14 above). This is necessary for one or two tests to keep the output
362        identical in both cases.
363    
364    21. When (*ACCEPT) was used in an assertion that matched an empty string and
365        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
366    
367    22. When an atomic group that contained a capturing parenthesis was
368        successfully matched, but the branch in which it appeared failed, the
369        capturing was not being forgotten if a higher numbered group was later
370        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
371        group 1 to "a", when in fact it should be unset. This applied to multi-
372        branched capturing and non-capturing groups, repeated or not, and also to
373        positive assertions (capturing in negative assertions does not happen
374        in PCRE) and also to nested atomic groups.
375    
376    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
377        subject after a captured substring, to make it easier to tell which of a
378        number of identical substrings has been captured.
379    
380    24. The way atomic groups are processed by pcre_exec() has been changed so that
381        if they are repeated, backtracking one repetition now resets captured
382        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
383        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
384        "aaa". Previously, it would have been "a". As part of this code
385        refactoring, the way recursive calls are handled has also been changed.
386    
387    25. If an assertion condition captured any substrings, they were not passed
388        back unless some other capturing happened later. For example, if
389        (?(?=(a))a) was matched against "a", no capturing was returned.
390    
391    26. When studying a pattern that contained subroutine calls or assertions,
392        the code for finding the minimum length of a possible match was handling
393        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
394        group 1 called group 2 while simultaneously a separate group 2 called group
395        1). A stack overflow occurred in this case. I have fixed this by limiting
396        the recursion depth to 10.
397    
398    27. Updated RunTest.bat in the distribution to the version supplied by Tom
399        Fortmann. This supports explicit test numbers on the command line, and has
400        argument validation and error reporting.
401    
402    28. An instance of \X with an unlimited repeat could fail if at any point the
403        first character it looked at was a mark character.
404    
405    29. Some minor code refactoring concerning Unicode properties and scripts
406        should reduce the stack requirement of match() slightly.
407    
408    30. Added the '=' option to pcretest to check the setting of unused capturing
409        slots at the end of the pattern, which are documented as being -1, but are
410        not included in the return count.
411    
412    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
413        compiled something random. Now it gives a compile-time error (as does
414        Perl).
415    
416    32. A *MARK encountered during the processing of a positive assertion is now
417        recorded and passed back (compatible with Perl).
418    
419    33. If --only-matching or --colour was set on a pcregrep call whose pattern
420        had alternative anchored branches, the search for a second match in a line
421        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
422        matched the line "0102" twice. The same bug affected patterns that started
423        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
424        twice.
425    
426    34. Previously, PCRE did not allow quantification of assertions. However, Perl
427        does, and because of capturing effects, quantifying parenthesized
428        assertions may at times be useful. Quantifiers are now allowed for
429        parenthesized assertions.
430    
431    35. A minor code tidy in pcre_compile() when checking options for \R usage.
432    
433    36. \g was being checked for fancy things in a character class, when it should
434        just be a literal "g".
435    
436    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
437        appearance of a nested POSIX class supersedes an apparent external class.
438        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
439        unescaped square brackets may also appear as part of class names. For
440        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
441        more like Perl. (But see 8.20/1 above.)
442    
443    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
444        was because it thought it was \N{name}, which is not supported).
445    
446    39. Add minix to OS list not supporting the -S option in pcretest.
447    
448    40. PCRE tries to detect cases of infinite recursion at compile time, but it
449        cannot analyze patterns in sufficient detail to catch mutual recursions
450        such as ((?1))((?2)). There is now a runtime test that gives an error if a
451        subgroup is called recursively as a subpattern for a second time at the
452        same position in the subject string. In previous releases this might have
453        been caught by the recursion limit, or it might have run out of stack.
454    
455    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
456        happen only once. PCRE was, however incorrectly giving a compile time error
457        "recursive call could loop indefinitely" because it cannot analyze the
458        pattern in sufficient detail. The compile time test no longer happens when
459        PCRE is compiling a conditional subpattern, but actual runaway loops are
460        now caught at runtime (see 40 above).
461    
462    42. It seems that Perl allows any characters other than a closing parenthesis
463        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
464        has been changed to be the same.
465    
466    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
467        as not to get warnings when autogen.sh is called. Also changed
468        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
469    
470    44. To help people who use pcregrep to scan files containing exceedingly long
471        lines, the following changes have been made:
472    
473        (a) The default value of the buffer size parameter has been increased from
474            8K to 20K. (The actual buffer used is three times this size.)
475    
476        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
477            PCRE is built.
478    
479        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
480            to be set at run time.
481    
482        (d) Numerical values in pcregrep options can be followed by K or M, for
483            example --buffer-size=50K.
484    
485        (e) If a line being scanned overflows pcregrep's buffer, an error is now
486            given and the return code is set to 2.
487    
488    45. Add a pointer to the latest mark to the callout data block.
489    
490    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
491        partial match of an empty string instead of no match. This was specific to
492        the use of ".".
493    
494    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
495        complete match instead of a partial match. This bug was dependent on both
496        the PCRE_UTF8 and PCRE_DOTALL options being set.
497    
498    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
499        starting byte set, because \b was not being ignored.
500    
501    
502    Version 8.12 15-Jan-2011
503    ------------------------
504    
505    1.  Fixed some typos in the markup of the man pages, and wrote a script that
506        checks for such things as part of the documentation building process.
507    
508    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
509        --match-limit and --recursion-limit options (added for 8.11). In
510        particular, this made one of the standard tests fail. (The integer value
511        went into the wrong half of a long int.)
512    
513    3.  If the --colour option was given to pcregrep with -v (invert match), it
514        did strange things, either producing crazy output, or crashing. It should,
515        of course, ignore a request for colour when reporting lines that do not
516        match.
517    
518    4.  Another pcregrep bug caused similar problems if --colour was specified with
519        -M (multiline) and the pattern match finished with a line ending.
520    
521    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
522        matched in multiline mode, the following line was shown as part of the
523        match. This seems wrong, so I have changed it.
524    
525    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
526        the check for further matches in the same line (so they could be coloured)
527        to overrun the end of the current line. If another match was found, it was
528        incorrectly shown (and then shown again when found in the next line).
529    
530    7.  If pcregrep was compiled under Windows, there was a reference to the
531        function pcregrep_exit() before it was defined. I am assuming this was
532        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
533        reported by a user. I've moved the definition above the reference.
534    
535    
536    Version 8.11 10-Dec-2010
537    ------------------------
538    
539    1.  (*THEN) was not working properly if there were untried alternatives prior
540        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
541        backtracked to try for "b" instead of moving to the next alternative branch
542        at the same level (in this case, to look for "c"). The Perl documentation
543        is clear that when (*THEN) is backtracked onto, it goes to the "next
544        alternative in the innermost enclosing group".
545    
546    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
547        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
548        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
549        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
550        (*THEN).
551    
552    3.  If \s appeared in a character class, it removed the VT character from
553        the class, even if it had been included by some previous item, for example
554        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
555        of \s, but is part of the POSIX "space" class.)
556    
557    4.  A partial match never returns an empty string (because you can always
558        match an empty string at the end of the subject); however the checking for
559        an empty string was starting at the "start of match" point. This has been
560        changed to the "earliest inspected character" point, because the returned
561        data for a partial match starts at this character. This means that, for
562        example, /(?<=abc)def/ gives a partial match for the subject "abc"
563        (previously it gave "no match").
564    
565    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
566        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
567        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
568        has an implication that the given string is incomplete (because a partial
569        match is preferred over a full match). For this reason, these items now
570        give a partial match in this situation. [Aside: previously, the one case
571        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
572        match rather than a full match, which was wrong by the old rules, but is
573        now correct.]
574    
575    6.  There was a bug in the handling of #-introduced comments, recognized when
576        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
577        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
578        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
579        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
580        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
581        places in pcre_compile().
582    
583    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
584        comments when looking ahead for named forward references to subpatterns,
585        the only newline sequence it recognized was NL. It now handles newlines
586        according to the set newline convention.
587    
588    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
589        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
590        cater for a lack of strerror(). These oversights have been fixed.
591    
592    9.  Added --match-limit and --recursion-limit to pcregrep.
593    
594    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
595    
596    11. When the -o option was used, pcregrep was setting a return code of 1, even
597        when matches were found, and --line-buffered was not being honoured.
598    
599    12. Added an optional parentheses number to the -o and --only-matching options
600        of pcregrep.
601    
602    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
603        can match an empty string. The code to do it in pcretest and pcredemo
604        needed fixing:
605    
606        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
607            only one byte after an empty string match just before CRLF (this case
608            just got forgotten; "any" and "anycrlf" were OK).
609    
610        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
611            mode when an empty string match preceded an ASCII character followed by
612            a non-ASCII character. (The code for advancing by one character rather
613            than one byte was nonsense.)
614    
615        (c) The pcredemo.c sample program did not have any code at all to handle
616            the cases when CRLF is a valid newline sequence.
617    
618    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
619        as a starting offset was within the subject string. There is now a new
620        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
621        negative or greater than the length of the string. In order to test this,
622        pcretest is extended to allow the setting of negative starting offsets.
623    
624    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
625        starting offset points to the beginning of a UTF-8 character was
626        unnecessarily clumsy. I tidied it up.
627    
628    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
629        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
630    
631    17. Nobody had reported that the --include_dir option, which was added in
632        release 7.7 should have been called --include-dir (hyphen, not underscore)
633        for compatibility with GNU grep. I have changed it to --include-dir, but
634        left --include_dir as an undocumented synonym, and the same for
635        --exclude-dir, though that is not available in GNU grep, at least as of
636        release 2.5.4.
637    
638    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
639        characters from a string of bytes) have been redefined so as not to use
640        loops, in order to improve performance in some environments. At the same
641        time, I abstracted some of the common code into auxiliary macros to save
642        repetition (this should not affect the compiled code).
643    
644    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
645        compile-time error is now given if \c is not followed by an ASCII
646        character, that is, a byte less than 128. (In EBCDIC mode, the code is
647        different, and any byte value is allowed.)
648    
649    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
650        START_OPTIMIZE option, which is now allowed at compile time - but just
651        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
652        to pcregrep and other applications that have no direct access to PCRE
653        options. The new /Y option in pcretest sets this option when calling
654        pcre_compile().
655    
656    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
657        back references. Groups containing recursive back references were forced to
658        be atomic by that change, but in the case of named groups, the amount of
659        memory required was incorrectly computed, leading to "Failed: internal
660        error: code overflow". This has been fixed.
661    
662    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
663        pcretest.c, to avoid build problems in some Borland environments.
664    
665    
666    Version 8.10 25-Jun-2010
667    ------------------------
668    
669    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
670        THEN.
671    
672    2.  (*ACCEPT) was not working when inside an atomic group.
673    
674    3.  Inside a character class, \B is treated as a literal by default, but
675        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
676        causes the error). The code is unchanged, but I tidied the documentation.
677    
678    4.  Inside a character class, PCRE always treated \R and \X as literals,
679        whereas Perl faults them if its -w option is set. I have changed PCRE so
680        that it faults them when PCRE_EXTRA is set.
681    
682    5.  Added support for \N, which always matches any character other than
683        newline. (It is the same as "." when PCRE_DOTALL is not set.)
684    
685    6.  When compiling pcregrep with newer versions of gcc which may have
686        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
687        declared with attribute warn_unused_result" were given. Just casting the
688        result to (void) does not stop the warnings; a more elaborate fudge is
689        needed. I've used a macro to implement this.
690    
691    7.  Minor change to pcretest.c to avoid a compiler warning.
692    
693    8.  Added four artifical Unicode properties to help with an option to make
694        \s etc use properties (see next item). The new properties are: Xan
695        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
696    
697    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
698        use Unicode properties. (*UCP) at the start of a pattern can be used to set
699        this option. Modified pcretest to add /W to test this facility. Added
700        REG_UCP to make it available via the POSIX interface.
701    
702    10. Added --line-buffered to pcregrep.
703    
704    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
705        studied, and the match started with a letter with a code point greater than
706        127 whose first byte was different to the first byte of the other case of
707        the letter, the other case of this starting letter was not recognized
708        (#976).
709    
710    12. If a pattern that was studied started with a repeated Unicode property
711        test, for example, \p{Nd}+, there was the theoretical possibility of
712        setting up an incorrect bitmap of starting bytes, but fortunately it could
713        not have actually happened in practice until change 8 above was made (it
714        added property types that matched character-matching opcodes).
715    
716    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
717        possible starting bytes for non-anchored patterns.
718    
719    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
720        \R, and also a number of cases that involve Unicode properties, both
721        explicit and implicit when PCRE_UCP is set.
722    
723    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
724        input, it could crash or give wrong results if characters with values
725        greater than 0xc0 were present in the subject string. (Detail: it assumed
726        UTF-8 input when processing these items.)
727    
728    16. Added a lot of (int) casts to avoid compiler warnings in systems where
729        size_t is 64-bit (#991).
730    
731    17. Added a check for running out of memory when PCRE is compiled with
732        --disable-stack-for-recursion (#990).
733    
734    18. If the last data line in a file for pcretest does not have a newline on
735        the end, a newline was missing in the output.
736    
737    19. The default pcre_chartables.c file recognizes only ASCII characters (values
738        less than 128) in its various bitmaps. However, there is a facility for
739        generating tables according to the current locale when PCRE is compiled. It
740        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
741        characters, are recognized by isspace() and therefore were getting set in
742        these tables, and indeed these tables seem to approximate to ISO 8859. This
743        caused a problem in UTF-8 mode when pcre_study() was used to create a list
744        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
745        which of course cannot start UTF-8 characters. I have changed the code so
746        that only real ASCII characters (less than 128) and the correct starting
747        bytes for UTF-8 encodings are set for characters greater than 127 when in
748        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
749        altogether.)
750    
751    20. Added the /T option to pcretest so as to be able to run tests with non-
752        standard character tables, thus making it possible to include the tests
753        used for 19 above in the standard set of tests.
754    
755    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
756        reference to a subpattern the other side of a comment that contains an
757        opening parenthesis caused either an internal compiling error, or a
758        reference to the wrong subpattern.
759    
760    
761    Version 8.02 19-Mar-2010
762    ------------------------
763    
764    1.  The Unicode data tables have been updated to Unicode 5.2.0.
765    
766    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
767        configured.
768    
769    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
770        original author of that file, following a query about its status.
771    
772    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
773        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
774    
775    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
776        quantifier applied to a forward-referencing subroutine call, could compile
777        incorrect code or give the error "internal error: previously-checked
778        referenced subpattern not found".
779    
780    6.  Both MS Visual Studio and Symbian OS have problems with initializing
781        variables to point to external functions. For these systems, therefore,
782        pcre_malloc etc. are now initialized to local functions that call the
783        relevant global functions.
784    
785    7.  There were two entries missing in the vectors called coptable and poptable
786        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
787        I've fixed the data, and added a kludgy way of testing at compile time that
788        the lengths are correct (equal to the number of opcodes).
789    
790    8.  Following on from 7, I added a similar kludge to check the length of the
791        eint vector in pcreposix.c.
792    
793    9.  Error texts for pcre_compile() are held as one long string to avoid too
794        much relocation at load time. To find a text, the string is searched,
795        counting zeros. There was no check for running off the end of the string,
796        which could happen if a new error number was added without updating the
797        string.
798    
799    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
800    
801    11. \K was not working if it appeared in an atomic group or in a group that
802        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
803        \K is "not well defined" if used in an assertion. PCRE now accepts it if
804        the assertion is positive, but not if it is negative.
805    
806    12. Change 11 fortuitously reduced the size of the stack frame used in the
807        "match()" function of pcre_exec.c by one pointer. Forthcoming
808        implementation of support for (*MARK) will need an extra pointer on the
809        stack; I have reserved it now, so that the stack frame size does not
810        decrease.
811    
812    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
813        item in branch that calls a recursion is a subroutine call - as in the
814        second branch in the above example - was incorrectly given the compile-
815        time error "recursive call could loop indefinitely" because pcre_compile()
816        was not correctly checking the subroutine for matching a non-empty string.
817    
818    14. The checks for overrunning compiling workspace could trigger after an
819        overrun had occurred. This is a "should never occur" error, but it can be
820        triggered by pathological patterns such as hundreds of nested parentheses.
821        The checks now trigger 100 bytes before the end of the workspace.
822    
823    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
824    
825    
826    Version 8.01 19-Jan-2010
827    ------------------------
828    
829    1.  If a pattern contained a conditional subpattern with only one branch (in
830        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
831        computed the wrong minimum data length (which is of course zero for such
832        subpatterns). This could cause incorrect "no match" results.
833    
834    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
835        the pattern is reset in the first branch, pcre_compile() failed with
836        "internal error: code overflow at offset...". This happened only when
837        the reset was to the original external option setting. (An optimization
838        abstracts leading options settings into an external setting, which was the
839        cause of this.)
840    
841    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
842        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
843        assertion pattern did not match (meaning that the assertion was true), it
844        was incorrectly treated as false if the SKIP had been reached during the
845        matching. This also applied to assertions used as conditions.
846    
847    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
848        assertion subpattern, including such a pattern used as a condition,
849        unpredictable results occurred, instead of the error return
850        PCRE_ERROR_DFA_UITEM.
851    
852    5.  The C++ GlobalReplace function was not working like Perl for the special
853        situation when an empty string is matched. It now does the fancy magic
854        stuff that is necessary.
855    
856    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
857        removed. (These were left over from very, very early versions of PCRE.)
858    
859    7.  Some cosmetic changes to the code to make life easier when compiling it
860        as part of something else:
861    
862        (a) Change DEBUG to PCRE_DEBUG.
863    
864        (b) In pcre_compile(), rename the member of the "branch_chain" structure
865            called "current" as "current_branch", to prevent a collision with the
866            Linux macro when compiled as a kernel module.
867    
868        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
869            prevent a collision with the Linux macro when compiled as a kernel
870            module.
871    
872    8.  In pcre_compile() there are some checks for integer overflows that used to
873        cast potentially large values to (double). This has been changed to that
874        when building, a check for int64_t is made, and if it is found, it is used
875        instead, thus avoiding the use of floating point arithmetic. (There is no
876        other use of FP in PCRE.) If int64_t is not found, the fallback is to
877        double.
878    
879    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
880        2005 (difference between two addresses compared to an unsigned value).
881    
882    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
883        custom one, because of the following reported problem in Windows:
884    
885          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
886              under Win32.
887          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
888              therefore missing the function definition.
889          - The compiler thus generates a "C" signature for the test function.
890          - The linker fails to find the "C" function.
891          - PCRE fails to configure if asked to do so against libbz2.
892    
893    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
894        messages were output:
895    
896          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
897          rerunning libtoolize, to keep the correct libtool macros in-tree.
898          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
899    
900        I have done both of these things.
901    
902    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
903        most of the time, it *can* run out if it is given a pattern that contains a
904        runaway infinite recursion. I updated the discussion in the pcrestack man
905        page.
906    
907    13. Now that we have gone to the x.xx style of version numbers, the minor
908        version may start with zero. Using 08 or 09 is a bad idea because users
909        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
910        interpreted as invalid octal numbers. I've updated the previous comment in
911        configure.ac, and also added a check that gives an error if 08 or 09 are
912        used.
913    
914    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
915        causing partial matching to fail when the end of the subject matched \W
916        in a UTF-8 pattern where \W was quantified with a minimum of 3.
917    
918    15. There were some discrepancies between the declarations in pcre_internal.h
919        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
920        their definitions. The declarations used "const uschar *" and the
921        definitions used USPTR. Even though USPTR is normally defined as "const
922        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
923        reported that: "This difference in casting confuses some C++ compilers, for
924        example, SunCC recognizes above declarations as different functions and
925        generates broken code for hbpcre." I have changed the declarations to use
926        USPTR.
927    
928    16. GNU libtool is named differently on some systems. The autogen.sh script now
929        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
930        (FreeBSD).
931    
932    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
933        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
934        comment: "Figure out how to create a longlong from a string: strtoll and
935        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
936        instance, but it only takes 2 args instead of 3!"
937    
938    18. A subtle bug concerned with back references has been fixed by a change of
939        specification, with a corresponding code fix. A pattern such as
940        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
941        refers, was giving matches when it shouldn't. For example, xa=xaaa would
942        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
943        same bug. Such groups have to be quantified to be useful, or contained
944        inside another quantified group. (If there's no repetition, the reference
945        can never match.) The problem arises because, having left the group and
946        moved on to the rest of the pattern, a later failure that backtracks into
947        the group uses the captured value from the final iteration of the group
948        rather than the correct earlier one. I have fixed this in PCRE by forcing
949        any group that contains a reference to itself to be an atomic group; that
950        is, there cannot be any backtracking into it once it has completed. This is
951        similar to recursive and subroutine calls.
952    
953    
954    Version 8.00 19-Oct-09
955    ----------------------
956    
957    1.  The table for translating pcre_compile() error codes into POSIX error codes
958        was out-of-date, and there was no check on the pcre_compile() error code
959        being within the table. This could lead to an OK return being given in
960        error.
961    
962    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
963        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
964        in a Windows environment.
965    
966    3.  The pcregrep --count option prints the count for each file even when it is
967        zero, as does GNU grep. However, pcregrep was also printing all files when
968        --files-with-matches was added. Now, when both options are given, it prints
969        counts only for those files that have at least one match. (GNU grep just
970        prints the file name in this circumstance, but including the count seems
971        more useful - otherwise, why use --count?) Also ensured that the
972        combination -clh just lists non-zero counts, with no names.
973    
974    4.  The long form of the pcregrep -F option was incorrectly implemented as
975        --fixed_strings instead of --fixed-strings. This is an incompatible change,
976        but it seems right to fix it, and I didn't think it was worth preserving
977        the old behaviour.
978    
979    5.  The command line items --regex=pattern and --regexp=pattern were not
980        recognized by pcregrep, which required --regex pattern or --regexp pattern
981        (with a space rather than an '='). The man page documented the '=' forms,
982        which are compatible with GNU grep; these now work.
983    
984    6.  No libpcreposix.pc file was created for pkg-config; there was just
985        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
986    
987    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
988        when UCP support is not needed, by modifying the Python script that
989        generates it from Unicode data files. This should not matter if the module
990        is correctly used as a library, but I received one complaint about 50K of
991        unwanted data. My guess is that the person linked everything into his
992        program rather than using a library. Anyway, it does no harm.
993    
994    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
995        was a minimum greater than 1 for a wide character in a possessive
996        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
997        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
998        character. Chaos in the form of incorrect output or a compiling loop could
999        result.
1000    
1001    9.  The restrictions on what a pattern can contain when partial matching is
1002        requested for pcre_exec() have been removed. All patterns can now be
1003        partially matched by this function. In addition, if there are at least two
1004        slots in the offset vector, the offset of the earliest inspected character
1005        for the match and the offset of the end of the subject are set in them when
1006        PCRE_ERROR_PARTIAL is returned.
1007    
1008    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1009        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1010        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1011        and may be more useful for multi-segment matching.
1012    
1013    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1014        used to be given if ever the end of the subject was reached; now it is
1015        given only if matching could not proceed because another character was
1016        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1017        string "Z", which now yields "no match" instead of "partial match". In the
1018        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1019        final character ended with (*FAIL).
1020    
1021    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1022        if the pattern had a "must contain" character that was already found in the
1023        earlier partial match, unless partial matching was again requested. For
1024        example, with the pattern /dog.(body)?/, the "must contain" character is
1025        "g". If the first part-match was for the string "dog", restarting with
1026        "sbody" failed. This bug has been fixed.
1027    
1028    13. The string returned by pcre_dfa_exec() after a partial match has been
1029        changed so that it starts at the first inspected character rather than the
1030        first character of the match. This makes a difference only if the pattern
1031        starts with a lookbehind assertion or \b or \B (\K is not supported by
1032        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1033        matching functions compatible, and I think it's the right thing to do.
1034    
1035    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1036        so that the demonstration program is easily available in environments where
1037        PCRE has not been installed from source.
1038    
1039    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1040        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1041        library.
1042    
1043    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1044        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1045        is not the first non-POSIX option to be added. Clearly some people find
1046        these options useful.
1047    
1048    17. If a caller to the POSIX matching function regexec() passes a non-zero
1049        value for nmatch with a NULL value for pmatch, the value of
1050        nmatch is forced to zero.
1051    
1052    18. RunGrepTest did not have a test for the availability of the -u option of
1053        the diff command, as RunTest does. It now checks in the same way as
1054        RunTest, and also checks for the -b option.
1055    
1056    19. If an odd number of negated classes containing just a single character
1057        interposed, within parentheses, between a forward reference to a named
1058        subpattern and the definition of the subpattern, compilation crashed with
1059        an internal error, complaining that it could not find the referenced
1060        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1061        [The bug was that it was starting one character too far in when skipping
1062        over the character class, thus treating the ] as data rather than
1063        terminating the class. This meant it could skip too much.]
1064    
1065    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1066        /g option in pcretest when the pattern contains \K, which makes it possible
1067        to have an empty string match not at the start, even when the pattern is
1068        anchored. Updated pcretest and pcredemo to use this option.
1069    
1070    21. If the maximum number of capturing subpatterns in a recursion was greater
1071        than the maximum at the outer level, the higher number was returned, but
1072        with unset values at the outer level. The correct (outer level) value is
1073        now given.
1074    
1075    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1076        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1077        make it do so. The string so far is captured, making this feature
1078        compatible with Perl.
1079    
1080    23. The tests have been re-organized, adding tests 11 and 12, to make it
1081        possible to check the Perl 5.10 features against Perl 5.10.
1082    
1083    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1084        pattern matches a fixed length string. PCRE did not allow this; now it
1085        does. Neither allows recursion.
1086    
1087    25. I finally figured out how to implement a request to provide the minimum
1088        length of subject string that was needed in order to match a given pattern.
1089        (It was back references and recursion that I had previously got hung up
1090        on.) This code has now been added to pcre_study(); it finds a lower bound
1091        to the length of subject needed. It is not necessarily the greatest lower
1092        bound, but using it to avoid searching strings that are too short does give
1093        some useful speed-ups. The value is available to calling programs via
1094        pcre_fullinfo().
1095    
1096    26. While implementing 25, I discovered to my embarrassment that pcretest had
1097        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1098        study optimizations had never been tested with that matching function.
1099        Oops. What is worse, even when it was passed study data, there was a bug in
1100        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1101        were also very few tests of studied patterns with pcre_dfa_exec().
1102    
1103    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1104        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1105        on the other side of the coin, they are no longer allowed to have different
1106        names, because these cannot be distinguished in PCRE, and this has caused
1107        confusion. (This is a difference from Perl.)
1108    
1109    28. When duplicate subpattern names are present (necessarily with different
1110        numbers, as required by 27 above), and a test is made by name in a
1111        conditional pattern, either for a subpattern having been matched, or for
1112        recursion in such a pattern, all the associated numbered subpatterns are
1113        tested, and the overall condition is true if the condition is true for any
1114        one of them. This is the way Perl works, and is also more like the way
1115        testing by number works.
1116    
1117    
1118    Version 7.9 11-Apr-09
1119    ---------------------
1120    
1121    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1122        (pcretest), all targets were linked against these libraries. This included
1123        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1124        libraries. This caused unwanted dependencies to be created. This problem
1125        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1126        pcretest is linked with readline.
1127    
1128    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1129        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1130        moved outside it again, because FALSE and TRUE are already defined in AIX,
1131        but BOOL is not.
1132    
1133    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1134        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1135    
1136    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1137        hyphens) following file names and line numbers when outputting matching
1138        lines. This is not true; no spaces are inserted. I have also clarified the
1139        wording for the --colour (or --color) option.
1140    
1141    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1142        was not coloured; this is different to GNU grep, so I have changed it to be
1143        the same.
1144    
1145    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1146        each matching line was coloured. Now it goes on to look for further matches
1147        of any of the test patterns, which is the same behaviour as GNU grep.
1148    
1149    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1150        doesn't make sense to accept an empty string match in pcregrep, so I have
1151        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1152        seems to be how GNU grep behaves.
1153    
1154    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1155        start or after a newline", because the conditional assertion was not being
1156        correctly handled. The rule now is that both the assertion and what follows
1157        in the first alternative must satisfy the test.
1158    
1159    9.  If auto-callout was enabled in a pattern with a conditional group whose
1160        condition was an assertion, PCRE could crash during matching, both with
1161        pcre_exec() and pcre_dfa_exec().
1162    
1163    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1164        used for matching.
1165    
1166    11. Unicode property support in character classes was not working for
1167        characters (bytes) greater than 127 when not in UTF-8 mode.
1168    
1169    12. Added the -M command line option to pcretest.
1170    
1171    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1172    
1173    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1174    
1175    16. Added comments and documentation about mis-use of no_arg in the C++
1176        wrapper.
1177    
1178    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1179        from Martin Jerabek that uses macro names for all relevant character and
1180        string constants.
1181    
1182    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1183        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1184        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1185        these, but not everybody uses configure.
1186    
1187    19. A conditional group that had only one branch was not being correctly
1188        recognized as an item that could match an empty string. This meant that an
1189        enclosing group might also not be so recognized, causing infinite looping
1190        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1191        with the subject "ab", where knowledge that the repeated group can match
1192        nothing is needed in order to break the loop.
1193    
1194    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1195        exec(), but without supplying a callout function, matching went wrong.
1196    
1197    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1198        leak if the size of the offset vector was greater than 30. When the vector
1199        is smaller, the saved offsets during recursion go onto a local stack
1200        vector, but for larger vectors malloc() is used. It was failing to free
1201        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1202        error, in fact).
1203    
1204    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1205        heapframe that is used only when UTF-8 support is enabled. This caused no
1206        problem, but was untidy.
1207    
1208    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1209        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1210        included within another project.
1211    
1212    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1213        slightly modified by me:
1214    
1215          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1216              not building pcregrep.
1217    
1218          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1219              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1220    
1221    25. Forward references, both numeric and by name, in patterns that made use of
1222        duplicate group numbers, could behave incorrectly or give incorrect errors,
1223        because when scanning forward to find the reference group, PCRE was not
1224        taking into account the duplicate group numbers. A pattern such as
1225        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1226    
1227    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1228        the feature of a custom pointer more persuasive (as requested by a user).
1229    
1230    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1231        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1232        pre-defined.
1233    
1234    28. Added support for (*UTF8) at the start of a pattern.
1235    
1236    29. Arrange for flags added by the "release type" setting in CMake to be shown
1237        in the configuration summary.
1238    
1239    
1240    Version 7.8 05-Sep-08
1241    ---------------------
1242    
1243    1.  Replaced UCP searching code with optimized version as implemented for Ad
1244        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1245        stage table and inline lookup instead of a function, giving speed ups of 2
1246        to 5 times on some simple patterns that I tested. Permission was given to
1247        distribute the MultiStage2.py script that generates the tables (it's not in
1248        the tarball, but is in the Subversion repository).
1249    
1250    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1251        scripts.
1252    
1253    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1254        a group with a zero qualifier. The result of the study could be incorrect,
1255        or the function might crash, depending on the pattern.
1256    
1257    4.  Caseless matching was not working for non-ASCII characters in back
1258        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1259        It now works when Unicode Property Support is available.
1260    
1261    5.  In pcretest, an escape such as \x{de} in the data was always generating
1262        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1263        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1264        truncation.
1265    
1266    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1267    
1268    7.  Added two (int) casts to pcregrep when printing the difference of two
1269        pointers, in case they are 64-bit values.
1270    
1271    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1272        test 2 if it fails.
1273    
1274    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1275        and a #define of that name to empty if it is not externally set. This is to
1276        allow users of MSVC to set it if necessary.
1277    
1278    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1279        the convenience functions in the pcre_get.c source file.
1280    
1281    11. An option change at the start of a pattern that had top-level alternatives
1282        could cause overwriting and/or a crash. This command provoked a crash in
1283        some environments:
1284    
1285          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1286    
1287        This potential security problem was recorded as CVE-2008-2371.
1288    
1289    12. For a pattern where the match had to start at the beginning or immediately
1290        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1291        pcre_dfa_exec() could read past the end of the passed subject if there was
1292        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1293        pcretest so that it places the subject at the end of its malloc-ed buffer.
1294    
1295    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1296        exec() might read past the end of the data buffer in UTF-8 mode.
1297    
1298    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1299        the data contained the byte 0x85 as part of a UTF-8 character within its
1300        first line. This applied both to normal and DFA matching.
1301    
1302    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1303        /^[^d]*?$/8 failed to match "abc".
1304    
1305    16. Added a missing copyright notice to pcrecpp_internal.h.
1306    
1307    17. Make it more clear in the documentation that values returned from
1308        pcre_exec() in ovector are byte offsets, not character counts.
1309    
1310    18. Tidied a few places to stop certain compilers from issuing warnings.
1311    
1312    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1313        supplied by Stefan Weber. I made a further small update for 7.8 because
1314        there is a change of source arrangements: the pcre_searchfuncs.c module is
1315        replaced by pcre_ucd.c.
1316    
1317    
1318    Version 7.7 07-May-08
1319    ---------------------
1320    
1321    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1322        a string to a long long, pretend we don't even have a long long." This is
1323        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1324    
1325    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1326        pre-7.6 versions, which defined a global no_arg variable instead of putting
1327        it in the RE class. (See also #8 below.)
1328    
1329    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1330        Lopes.
1331    
1332    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1333    
1334        (1) The include/exclude patterns were being applied to the whole pathnames
1335            of files, instead of just to the final components.
1336    
1337        (2) If there was more than one level of directory, the subdirectories were
1338            skipped unless they satisfied the include/exclude conditions. This is
1339            inconsistent with GNU grep (and could even be seen as contrary to the
1340            pcregrep specification - which I improved to make it absolutely clear).
1341            The action now is always to scan all levels of directory, and just
1342            apply the include/exclude patterns to regular files.
1343    
1344    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1345        --exclude_dir in the tests to avoid scanning .svn directories.
1346    
1347    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1348        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1349        doesn't support NULs in patterns.
1350    
1351    7.  Added some missing "const"s to declarations of static tables in
1352        pcre_compile.c and pcre_dfa_exec.c.
1353    
1354    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1355        caused by fix #2  above. (Subsequently also a second patch to fix the
1356        first patch. And a third patch - this was a messy problem.)
1357    
1358    9.  Applied Craig's patch to remove the use of push_back().
1359    
1360    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1361        matching function regexec().
1362    
1363    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1364        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1365        references. PCRE supports relative numbers with this syntax (I don't think
1366        Oniguruma does).
1367    
1368    12. Previously, a group with a zero repeat such as (...){0} was completely
1369        omitted from the compiled regex. However, this means that if the group
1370        was called as a subroutine from elsewhere in the pattern, things went wrong
1371        (an internal error was given). Such groups are now left in the compiled
1372        pattern, with a new opcode that causes them to be skipped at execution
1373        time.
1374    
1375    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1376        to the way PCRE behaves:
1377    
1378        (a) A lone ] character is dis-allowed (Perl treats it as data).
1379    
1380        (b) A back reference to an unmatched subpattern matches an empty string
1381            (Perl fails the current match path).
1382    
1383        (c) A data ] in a character class must be notated as \] because if the
1384            first data character in a class is ], it defines an empty class. (In
1385            Perl it is not possible to have an empty class.) The empty class []
1386            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1387            The negative empty class [^] matches any one character, independently
1388            of the DOTALL setting.
1389    
1390    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1391        non-existent subpattern following a character class starting with ']' and
1392        containing () gave an internal compiling error instead of "reference to
1393        non-existent subpattern". Fortunately, when the pattern did exist, the
1394        compiled code was correct. (When scanning forwards to check for the
1395        existencd of the subpattern, it was treating the data ']' as terminating
1396        the class, so got the count wrong. When actually compiling, the reference
1397        was subsequently set up correctly.)
1398    
1399    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1400        it was being rejected as not supported by pcre_dfa_exec(), even though
1401        other assertions are supported. I have made pcre_dfa_exec() support
1402        (*FAIL).
1403    
1404    16. The implementation of 13c above involved the invention of a new opcode,
1405        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1406        cannot be changed at match time, I realized I could make a small
1407        improvement to matching performance by compiling OP_ALLANY instead of
1408        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1409        on the OP_ANY path.
1410    
1411    17. Compiling pcretest on Windows with readline support failed without the
1412        following two fixes: (1) Make the unistd.h include conditional on
1413        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1414    
1415    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1416        ncurses library to be included for pcretest when ReadLine support is
1417        requested, but also to allow for it to be overridden. This patch came from
1418        Daniel Bergström.
1419    
1420    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1421        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1422        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1423        spotting this.
1424    
1425    
1426    Version 7.6 28-Jan-08
1427    ---------------------
1428    
1429    1.  A character class containing a very large number of characters with
1430        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1431        overflow.
1432    
1433    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1434        HAVE_LONG_LONG is not defined.
1435    
1436    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1437        bring them up to date and include new features. This patch includes:
1438    
1439        - Fixed PH's badly added libz and libbz2 support.
1440        - Fixed a problem with static linking.
1441        - Added pcredemo. [But later removed - see 7 below.]
1442        - Fixed dftables problem and added an option.
1443        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1444            HAVE_LONG_LONG.
1445        - Added readline support for pcretest.
1446        - Added an listing of the option settings after cmake has run.
1447    
1448    4.  A user submitted a patch to Makefile that makes it easy to create
1449        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1450        Makefile.am that cause it to include this special target, without
1451        affecting anything else. Note that the same mingw target plus all
1452        the other distribution libraries and programs are now supported
1453        when configuring with CMake (see 6 below) instead of with
1454        Configure/Make.
1455    
1456    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1457        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1458        exported in the Windows port". It has not yet been confirmed that the patch
1459        solves the problem, but it does no harm.
1460    
1461    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1462        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1463        with CMake, and also correct the comment about stack recursion.
1464    
1465    7.  Remove the automatic building of pcredemo from the ./configure system and
1466        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1467        of a program that users should build themselves after PCRE is installed, so
1468        building it automatically is not really right. What is more, it gave
1469        trouble in some build environments.
1470    
1471    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1472    
1473    
1474    Version 7.5 10-Jan-08
1475  ---------------------  ---------------------
1476    
1477  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'
1478      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1479    
1480  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.
1481      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1482      included.      included.
1483    
1484  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
1485      [:^space:].      [:^space:].
1486    
1487  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
1488      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
1489      I have changed it.      I have changed it.
1490    
1491  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
1492      first named subpattern) and a construct such as (?&a) would reference the      first named subpattern) and a construct such as (?&a) would reference the
1493      first named subpattern whose name started with "a" (in other words, the      first named subpattern whose name started with "a" (in other words, the
1494      length check was missing). Both these problems are fixed. "Subpattern name      length check was missing). Both these problems are fixed. "Subpattern name
1495      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
1496      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
1497      was a reference to a non-existent subpattern).      was a reference to a non-existent subpattern).
1498    
1499  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1500      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
1501      digits. I have, however, made the messages clearer.      digits. I have, however, made the messages clearer.
1502    
1503  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
1504      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.
1505      This is actually not compatible with Perl, which accepts such patterns, but      This is actually not compatible with Perl, which accepts such patterns, but
1506      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
1507      seems to me that giving a diagnostic is better.      seems to me that giving a diagnostic is better.
1508    
1509  8.  Change "alphameric" to the more common word "alphanumeric" in comments  8.  Change "alphameric" to the more common word "alphanumeric" in comments
1510      and messages.      and messages.
1511    
1512  9.  Fix two occurrences of "backslash" in comments that should have been  9.  Fix two occurrences of "backslash" in comments that should have been
1513      "backspace".      "backspace".
1514    
1515  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
1516      was moved elsewhere).      was moved elsewhere).
1517    
1518  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
1519      which caused it to generate incorrect table entries for sequences of      which caused it to generate incorrect table entries for sequences of
1520      characters that have the same character type, but are in different scripts.      characters that have the same character type, but are in different scripts.
1521      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
1522      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
1523      thirteen such cases, affecting characters in the following ranges:      thirteen such cases, affecting characters in the following ranges:
1524    
1525        U+002b0 - U+002c1        U+002b0 - U+002c1
1526        U+0060c - U+0060d        U+0060c - U+0060d
1527        U+0061e - U+00612        U+0061e - U+00612
1528        U+0064b - U+0065e        U+0064b - U+0065e
1529        U+0074d - U+0076d        U+0074d - U+0076d
1530        U+01800 - U+01805        U+01800 - U+01805
# Line 65  Version 7.5 12-Nov-07 Line 1535  Version 7.5 12-Nov-07
1535        U+03260 - U+0327f        U+03260 - U+0327f
1536        U+0fb46 - U+0fbb1        U+0fb46 - U+0fbb1
1537        U+10450 - U+1049d        U+10450 - U+1049d
1538    
1539  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
1540      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
1541      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
1542      GNU grep.      GNU grep.
1543    
1544  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
1545      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
1546      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
1547      non-matching lines.      non-matching lines.
1548    
1549  14. The pattern (?=something)(?R) was not being diagnosed as a potentially  14. Added --file-offsets and --line-offsets to pcregrep.
1550    
1551    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1552      infinitely looping recursion. The bug was that positive lookaheads were not      infinitely looping recursion. The bug was that positive lookaheads were not
1553      being skipped when checking for a possible empty match (negative lookaheads      being skipped when checking for a possible empty match (negative lookaheads
1554      and both kinds of lookbehind were skipped).      and both kinds of lookbehind were skipped).
1555    
1556  15. Fixed two typos in the Windows-only code in pcregrep.c, and moved the  16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1557      inclusion of <windows.h> to before rather than after the definition of      inclusion of <windows.h> to before rather than after the definition of
1558      INVALID_FILE_ATTRIBUTES (patch from David Byron).      INVALID_FILE_ATTRIBUTES (patch from David Byron).
1559    
1560  16. Specifying a possessive quantifier with a specific limit for a Unicode  17. Specifying a possessive quantifier with a specific limit for a Unicode
1561      character property caused pcre_compile() to compile bad code, which led at      character property caused pcre_compile() to compile bad code, which led at
1562      runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this      runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1563      are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that      are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1564      caused the error; without that there was no problem.      caused the error; without that there was no problem.
1565    
1566    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1567    
1568    19. Added --enable-pcretest-libreadline.
1569    
1570    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1571        RE::GlobalReplace(). As a result, the number of replacements returned was
1572        double what it should be. I removed one of the increments, but Craig sent a
1573        later patch that removed the other one (the right fix) and added unit tests
1574        that check the return values (which was not done before).
1575    
1576    21. Several CMake things:
1577    
1578        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1579            the names libpcre and libpcreposix, not just pcre and pcreposix.
1580    
1581        (2) The above change means that pcretest and pcregrep are now correctly
1582            linked with the newly-built libraries, not previously installed ones.
1583    
1584        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1585    
1586    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1587        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1588        UTF-8 newline character). The key issue is that the pattern starts .*;
1589        this means that the match must be either at the beginning, or after a
1590        newline. The bug was in the code for advancing after a failed match and
1591        checking that the new position followed a newline. It was not taking
1592        account of UTF-8 characters correctly.
1593    
1594    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1595        character classes. PCRE was not treating the sequence [:...:] as a
1596        character class unless the ... were all letters. Perl, however, seems to
1597        allow any characters between [: and :], though of course it rejects as
1598        unknown any "names" that contain non-letters, because all the known class
1599        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1600        for example, whereas PCRE did not - it did not recognize a POSIX character
1601        class. This seemed a bit dangerous, so the code has been changed to be
1602        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1603        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1604        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1605        Perl does, and where it didn't before.
1606    
1607    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1608        Windows environments %n is disabled by default.
1609    
1610    
1611  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07

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