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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.0 02 Jul-08  Version 8.32
5    ------------
6    
7    1.  Improved JIT compiler optimizations for first character search and single
8        character iterators.
9    
10    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11        Patch by Daniel Richard G.
12    
13    3.  Single character iterator optimizations in the JIT compiler.
14    
15    4.  Improved JIT compiler optimizations for character ranges.
16    
17    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
18        Reported by Giuseppe D'Angelo.
19    
20    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
21        of a line, was being set incorrectly in cases where .* appeared inside
22        atomic brackets at the start of a pattern, or where there was a subsequent
23        *PRUNE or *SKIP.
24    
25    7.  Improved instruction cache flush for POWER/PowerPC.
26        Patch by Daniel Richard G.
27    
28    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
29        grep:
30    
31        (a) There is now no limit to the number of patterns to be matched.
32    
33        (b) An error is given if a pattern is too long.
34    
35        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
36            are now supported.
37    
38        (d) --exclude-from and --include-from (multiple use) have been added.
39    
40        (e) Exclusions and inclusions now apply to all files and directories, not
41            just to those obtained from scanning a directory recursively.
42    
43        (f) Multiple uses of -f and --file-list are now supported.
44    
45        (g) In a Windows environment, the default for -d has been changed from
46            "read" (the GNU grep default) to "skip", because otherwise the presence
47            of a directory in the file list provokes an error.
48    
49        (h) The documentation has been revised and clarified in places.
50    
51    9.  Improve the matching speed of capturing brackets.
52    
53    10. Changed the meaning of \X so that it now matches a Unicode extended
54        grapheme cluster.
55    
56    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
57        out POSIX threads when JIT support is configured.
58    
59    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
60    
61    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
62        structure could go wrong in environments where size_t is not the same size
63        as int.
64    
65    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
66        set.
67    
68    15. The EBCDIC support had decayed; later updates to the code had included
69        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
70        general tidy up of EBCDIC-related issues, and the documentation was also
71        not quite right. There is now a test that can be run on ASCII systems to
72        check some of the EBCDIC-related things (but is it not a full test).
73    
74    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
75        in a small tidy to the code.
76    
77    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
78    
79    18. If the --only-matching (-o) option in pcregrep is specified multiple
80        times, each one causes appropriate output. For example, -o1 -o2 outputs the
81        substrings matched by the 1st and 2nd capturing parentheses. A separating
82        string can be specified by --om-separator (default empty).
83    
84    19. Improving the first n character searches.
85    
86    20. Turn case lists for horizontal and vertical white space into macros so that
87        they are defined only once.
88    
89    21. This set of changes together give more compatible Unicode case-folding
90        behaviour for characters that have more than one other case when UCP
91        support is available.
92    
93        (a) The Unicode property table now has offsets into a new table of sets of
94            three or more characters that are case-equivalent. The MultiStage2.py
95            script that generates these tables (the pcre_ucd.c file) now scans
96            CaseFolding.txt instead of UnicodeData.txt for character case
97            information.
98    
99        (b) The code for adding characters or ranges of characters to a character
100            class has been abstracted into a generalized function that also handles
101            case-independence. In UTF-mode with UCP support, this uses the new data
102            to handle characters with more than one other case.
103    
104        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
105            whose other case is greater than 256 are now correctly matched
106            caselessly. Previously, the high codepoint matched the low one, but not
107            vice versa.
108    
109        (d) The processing of \h, \H, \v, and \ in character classes now makes use
110            of the new class addition function, using character lists defined as
111            macros alongside the case definitions of 20 above.
112    
113        (e) Caseless back references now work with characters that have more than
114            one other case.
115    
116        (f) General caseless matching of characters with more than one other case
117            is supported.
118    
119    
120    Version 8.31 06-July-2012
121    -------------------------
122    
123    1.  Fixing a wrong JIT test case and some compiler warnings.
124    
125    2.  Removed a bashism from the RunTest script.
126    
127    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
128        to unsigned type, result still unsigned" that was given by an MS compiler
129        on encountering the code "-sizeof(xxx)".
130    
131    4.  Partial matching support is added to the JIT compiler.
132    
133    5.  Fixed several bugs concerned with partial matching of items that consist
134        of more than one character:
135    
136        (a) /^(..)\1/ did not partially match "aba" because checking references was
137            done on an "all or nothing" basis. This also applied to repeated
138            references.
139    
140        (b) \R did not give a hard partial match if \r was found at the end of the
141            subject.
142    
143        (c) \X did not give a hard partial match after matching one or more
144            characters at the end of the subject.
145    
146        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
147            a partial match for the string "\r".
148    
149        (e) When newline was set to CRLF, the metacharacter "." did not recognize
150            a partial match for a CR character at the end of the subject string.
151    
152    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
153        running pcretest, the text "(JIT)" added to the output whenever JIT is
154        actually used to run the match.
155    
156    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
157        or /S+[+] with a digit between 1 and 7.
158    
159    8.  OP_NOT now supports any UTF character not just single-byte ones.
160    
161    9.  (*MARK) control verb is now supported by the JIT compiler.
162    
163    10. The command "./RunTest list" lists the available tests without actually
164        running any of them. (Because I keep forgetting what they all are.)
165    
166    11. Add PCRE_INFO_MAXLOOKBEHIND.
167    
168    12. Applied a (slightly modified) user-supplied patch that improves performance
169        when the heap is used for recursion (compiled with --disable-stack-for-
170        recursion). Instead of malloc and free for each heap frame each time a
171        logical recursion happens, frames are retained on a chain and re-used where
172        possible. This sometimes gives as much as 30% improvement.
173    
174    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
175        call.
176    
177    14. As documented, (*COMMIT) is now confined to within a positive assertion.
178    
179    15. It is now possible to link pcretest with libedit as an alternative to
180        libreadline.
181    
182    16. (*COMMIT) control verb is now supported by the JIT compiler.
183    
184    17. The Unicode data tables have been updated to Unicode 6.1.0.
185    
186    18. Added --file-list option to pcregrep.
187    
188    19. Added binary file support to pcregrep, including the -a, --binary-files,
189        -I, and --text options.
190    
191    20. The madvise function is renamed for posix_madvise for QNX compatibility
192        reasons. Fixed by Giuseppe D'Angelo.
193    
194    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
195    
196    22. Changed the option for creating symbolic links for 16-bit man pages from
197        -s to -sf so that re-installing does not cause issues.
198    
199    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
200    
201    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
202        matches in certain environments (the workspace was not being correctly
203        retained). Also added to pcre_dfa_exec() a simple plausibility check on
204        some of the workspace data at the beginning of a restart.
205    
206    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
207        was not doing so when it should - probably a typo introduced by SVN 528
208        (change 8.10/14).
209    
210    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
211        \w+ when the character tables indicated that \x{c4} was a word character.
212        There were several related cases, all because the tests for doing a table
213        lookup were testing for characters less than 127 instead of 255.
214    
215    27. If a pattern contains capturing parentheses that are not used in a match,
216        their slots in the ovector are set to -1. For those that are higher than
217        any matched groups, this happens at the end of processing. In the case when
218        there were back references that the ovector was too small to contain
219        (causing temporary malloc'd memory to be used during matching), and the
220        highest capturing number was not used, memory off the end of the ovector
221        was incorrectly being set to -1. (It was using the size of the temporary
222        memory instead of the true size.)
223    
224    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
225        ovector size, it uses memory at the end of the block that it has got.
226    
227    29. Check for an overlong MARK name and give an error at compile time. The
228        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
229    
230    30. JIT compiler update.
231    
232    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
233        Rill for the patch.
234    
235    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
236    
237    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
238    
239    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
240        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
241        was enabled.
242    
243    35. Improve JIT code generation for greedy plus quantifier.
244    
245    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
246        1 to "aa" instead of to an empty string. The bug affected repeated groups
247        that could potentially match an empty string.
248    
249    37. Optimizing single character iterators in JIT.
250    
251    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
252        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
253        codepoints that are too big for the mode are faulted, and in a UTF mode,
254        disallowed codepoints are also faulted.
255    
256    39. If PCRE was compiled with UTF support, in three places in the DFA
257        matcher there was code that should only have been obeyed in UTF mode, but
258        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
259        processing when bytes with values greater than 127 were present. In 16-bit
260        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
261        both cases the values are those that cannot be the first data item in a UTF
262        character. The three items that might have provoked this were recursions,
263        possessively repeated groups, and atomic groups.
264    
265    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
266        and pcregrep, because some OS require shared objects to be explicitly
267        passed to ld, causing the link step to fail if they are not.
268    
269    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
270        mode, patterns that started with \h* or \R* might be incorrectly matched.
271    
272    
273    Version 8.30 04-February-2012
274    -----------------------------
275    
276    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
277        name is defined in ctype.h.
278    
279    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
280        only in quite long subpatterns.
281    
282    3.  Removed the function pcre_info(), which has been obsolete and deprecated
283        since it was replaced by pcre_fullinfo() in February 2000.
284    
285    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
286        match a (*MARK), and the match failed at the start of the subject, a
287        reference to memory before the start of the subject could occur. This bug
288        was introduced by fix 17 of release 8.21.
289    
290    5.  A reference to an unset group with zero minimum repetition was giving
291        totally wrong answers (in non-JavaScript-compatibility mode). For example,
292        /(another)?(\1?)test/ matched against "hello world test". This bug was
293        introduced in release 8.13.
294    
295    6.  Add support for 16-bit character strings (a large amount of work involving
296        many changes and refactorings).
297    
298    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
299        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
300        from a file.
301    
302    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
303        rounding is not applied in this particular case).
304    
305    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
306        if they appear, or are escaped, in patterns.
307    
308    10. Get rid of a number of -Wunused-but-set-variable warnings.
309    
310    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
311        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
312        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
313        also returns the mark "x". This bug applied to capturing parentheses,
314        non-capturing parentheses, and atomic parentheses. It also applied to some
315        assertions.
316    
317    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
318        information out of configure.ac instead of relying on pcre.h.generic, which
319        is not stored in the repository.
320    
321    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
322        -lreadline.
323    
324    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
325    
326    15. Applied Graycode's patch to put the top-level frame on the stack rather
327        than the heap when not using the stack for recursion. This gives a
328        performance improvement in many cases when recursion is not deep.
329    
330    16. Experimental code added to "pcretest -C" to output the stack frame size.
331    
332    
333    Version 8.21 12-Dec-2011
334    ------------------------
335    
336    1.  Updating the JIT compiler.
337    
338    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
339        are added as well.
340    
341    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
342        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
343        calling _pcre_jit_exec. Some extra comments are added.
344    
345    4.  (*MARK) settings inside atomic groups that do not contain any capturing
346        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
347        was introduced by change 18 for 8.20.
348    
349    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
350        ECMA-262 standard.
351    
352    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
353        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
354        This bug was probably introduced by change 9 of 8.13.
355    
356    7.  While fixing 6 above, I noticed that a number of other items were being
357        incorrectly rejected as "not fixed length". This arose partly because newer
358        opcodes had not been added to the fixed-length checking code. I have (a)
359        corrected the bug and added tests for these items, and (b) arranged for an
360        error to occur if an unknown opcode is encountered while checking for fixed
361        length instead of just assuming "not fixed length". The items that were
362        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
363        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
364        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
365    
366    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
367        being incorrectly compiled and would have given unpredicatble results.
368    
369    9.  A possessively repeated subpattern with minimum repeat count greater than
370        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
371        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
372        the first (A) could occur when it should not.
373    
374    10. Add a cast and remove a redundant test from the code.
375    
376    11. JIT should use pcre_malloc/pcre_free for allocation.
377    
378    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
379        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
380        is anything other than /usr, -L is still shown).
381    
382    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
383    
384    14. Perl does not support \N without a following name in a [] class; PCRE now
385        also gives an error.
386    
387    15. If a forward reference was repeated with an upper limit of around 2000,
388        it caused the error "internal error: overran compiling workspace". The
389        maximum number of forward references (including repeats) was limited by the
390        internal workspace, and dependent on the LINK_SIZE. The code has been
391        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
392        the default depends on LINK_SIZE. There is a new upper limit (for safety)
393        of around 200,000 forward references. While doing this, I also speeded up
394        the filling in of repeated forward references.
395    
396    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
397        incorrectly expecting the subject to contain another "a" after the start.
398    
399    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
400        in the match, the SKIP should be ignored. This was not happening; instead
401        the SKIP was being treated as NOMATCH. For patterns such as
402        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
403        tested.
404    
405    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
406        now much more compatible with Perl, in particular in cases where the result
407        is a non-match for a non-anchored pattern. For example, if
408        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
409        "m", where previously it did not return a name. A side effect of this
410        change is that for partial matches, the last encountered mark name is
411        returned, as for non matches. A number of tests that were previously not
412        Perl-compatible have been moved into the Perl-compatible test files. The
413        refactoring has had the pleasing side effect of removing one argument from
414        the match() function, thus reducing its stack requirements.
415    
416    19. If the /S+ option was used in pcretest to study a pattern using JIT,
417        subsequent uses of /S (without +) incorrectly behaved like /S+.
418    
419    21. Retrieve executable code size support for the JIT compiler and fixing
420        some warnings.
421    
422    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
423        not work when the shorter character appeared right at the end of the
424        subject string.
425    
426    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
427        systems.
428    
429    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
430        output it when the /M option is used in pcretest.
431    
432    25. The CheckMan script was not being included in the distribution. Also, added
433        an explicit "perl" to run Perl scripts from the PrepareRelease script
434        because this is reportedly needed in Windows.
435    
436    26. If study data was being save in a file and studying had not found a set of
437        "starts with" bytes for the pattern, the data written to the file (though
438        never used) was taken from uninitialized memory and so caused valgrind to
439        complain.
440    
441    27. Updated RunTest.bat as provided by Sheri Pierce.
442    
443    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
444    
445    29. Computation of memory usage for the table of capturing group names was
446        giving an unnecessarily large value.
447    
448    
449    Version 8.20 21-Oct-2011
450    ------------------------
451    
452    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
453        a POSIX class. After further experiments with Perl, which convinced me that
454        Perl has bugs and confusions, a closing square bracket is no longer allowed
455        in a POSIX name. This bug also affected patterns with classes that started
456        with full stops.
457    
458    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
459        captured substring, but while checking the failing first alternative,
460        substring 1 is temporarily captured. If the output vector supplied to
461        pcre_exec() was not big enough for this capture, the yield of the function
462        was still zero ("insufficient space for captured substrings"). This cannot
463        be totally fixed without adding another stack variable, which seems a lot
464        of expense for a edge case. However, I have improved the situation in cases
465        such as /(a)(b)x|abc/ matched against "abc", where the return code
466        indicates that fewer than the maximum number of slots in the ovector have
467        been set.
468    
469    3.  Related to (2) above: when there are more back references in a pattern than
470        slots in the output vector, pcre_exec() uses temporary memory during
471        matching, and copies in the captures as far as possible afterwards. It was
472        using the entire output vector, but this conflicts with the specification
473        that only 2/3 is used for passing back captured substrings. Now it uses
474        only the first 2/3, for compatibility. This is, of course, another edge
475        case.
476    
477    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
478        main code base, and can be used by building with --enable-jit. When this is
479        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
480        runtime --no-jit option is given.
481    
482    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
483        ovector, the return from the function was zero, implying that there were
484        other matches that did not fit. The correct "exactly full" value is now
485        returned.
486    
487    6.  If a subpattern that was called recursively or as a subroutine contained
488        (*PRUNE) or any other control that caused it to give a non-standard return,
489        invalid errors such as "Error -26 (nested recursion at the same subject
490        position)" or even infinite loops could occur.
491    
492    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
493        computing the minimum length on reaching *ACCEPT, and so ended up with the
494        wrong value of 1 rather than 0. Further investigation indicates that
495        computing a minimum subject length in the presence of *ACCEPT is difficult
496        (think back references, subroutine calls), and so I have changed the code
497        so that no minimum is registered for a pattern that contains *ACCEPT.
498    
499    8.  If (*THEN) was present in the first (true) branch of a conditional group,
500        it was not handled as intended. [But see 16 below.]
501    
502    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
503        Sheri Pierce.
504    
505    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
506        the first byte in a match must be "a".
507    
508    11. Change 17 for 8.13 increased the recursion depth for patterns like
509        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
510        pattern contains any instances of (*THEN). If it does not, the old
511        optimizations are restored. It would be nice to do this on a per-group
512        basis, but at the moment that is not feasible.
513    
514    12. In some environments, the output of pcretest -C is CRLF terminated. This
515        broke RunTest's code that checks for the link size. A single white space
516        character after the value is now allowed for.
517    
518    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
519        For "fr", it uses the Windows-specific input and output files.
520    
521    14. If (*THEN) appeared in a group that was called recursively or as a
522        subroutine, it did not work as intended. [But see next item.]
523    
524    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
525        pattern fragments (but not containing any | characters). If A and B are
526        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
527        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
528        D. In other words, Perl considers parentheses that do not contain any |
529        characters to be part of a surrounding alternative, whereas PCRE was
530        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
531        differently. PCRE now behaves in the same way as Perl, except in the case
532        of subroutine/recursion calls such as (?1) which have in any case always
533        been different (but PCRE had them first :-).
534    
535    16. Related to 15 above: Perl does not treat the | in a conditional group as
536        creating alternatives. Such a group is treated in the same way as an
537        ordinary group without any | characters when processing (*THEN). PCRE has
538        been changed to match Perl's behaviour.
539    
540    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
541        RunGrepTest script failed.
542    
543    18. Change 22 for version 13 caused atomic groups to use more stack. This is
544        inevitable for groups that contain captures, but it can lead to a lot of
545        stack use in large patterns. The old behaviour has been restored for atomic
546        groups that do not contain any capturing parentheses.
547    
548    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
549        suppress the check for a minimum subject length at run time. (If it was
550        given to pcre_exec() or pcre_dfa_exec() it did work.)
551    
552    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
553        fail to work when decoding hex characters in data strings in EBCDIC
554        environments.
555    
556    21. It appears that in at least one Mac OS environment, the isxdigit() function
557        is implemented as a macro that evaluates to its argument more than once,
558        contravening the C 90 Standard (I haven't checked a later standard). There
559        was an instance in pcretest which caused it to go wrong when processing
560        \x{...} escapes in subject strings. The has been rewritten to avoid using
561        things like p++ in the argument of isxdigit().
562    
563    
564    Version 8.13 16-Aug-2011
565    ------------------------
566    
567    1.  The Unicode data tables have been updated to Unicode 6.0.0.
568    
569    2.  Two minor typos in pcre_internal.h have been fixed.
570    
571    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
572        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
573        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
574    
575    4.  There were a number of related bugs in the code for matching backrefences
576        caselessly in UTF-8 mode when codes for the characters concerned were
577        different numbers of bytes. For example, U+023A and U+2C65 are an upper
578        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
579        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
580        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
581        2-byte code at the end of the subject (it thought there wasn't enough data
582        left).
583    
584    5.  Comprehensive information about what went wrong is now returned by
585        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
586        as the output vector has at least 2 elements. The offset of the start of
587        the failing character and a reason code are placed in the vector.
588    
589    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
590        now returned is for the first byte of the failing character, instead of the
591        last byte inspected. This is an incompatible change, but I hope it is small
592        enough not to be a problem. It makes the returned offset consistent with
593        pcre_exec() and pcre_dfa_exec().
594    
595    7.  pcretest now gives a text phrase as well as the error number when
596        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
597        failure, the offset and reason code are output.
598    
599    8.  When \R was used with a maximizing quantifier it failed to skip backwards
600        over a \r\n pair if the subsequent match failed. Instead, it just skipped
601        back over a single character (\n). This seems wrong (because it treated the
602        two characters as a single entity when going forwards), conflicts with the
603        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
604        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
605        has been changed.
606    
607    9.  Some internal refactoring has changed the processing so that the handling
608        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
609        time (the PCRE_DOTALL option was changed this way some time ago: version
610        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
611        which was always a bit of a fudge. It also means that there is one less
612        argument for the match() function, which reduces its stack requirements
613        slightly. This change also fixes an incompatibility with Perl: the pattern
614        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
615    
616    10. More internal refactoring has drastically reduced the number of recursive
617        calls to match() for possessively repeated groups such as (abc)++ when
618        using pcre_exec().
619    
620    11. While implementing 10, a number of bugs in the handling of groups were
621        discovered and fixed:
622    
623        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
624        (a|)*(?1) gave a compile-time internal error.
625        ((a|)+)+  did not notice that the outer group could match an empty string.
626        (^a|^)+   was not marked as anchored.
627        (.*a|.*)+ was not marked as matching at start or after a newline.
628    
629    12. Yet more internal refactoring has removed another argument from the match()
630        function. Special calls to this function are now indicated by setting a
631        value in a variable in the "match data" data block.
632    
633    13. Be more explicit in pcre_study() instead of relying on "default" for
634        opcodes that mean there is no starting character; this means that when new
635        ones are added and accidentally left out of pcre_study(), testing should
636        pick them up.
637    
638    14. The -s option of pcretest has been documented for ages as being an old
639        synonym of -m (show memory usage). I have changed it to mean "force study
640        for every regex", that is, assume /S for every regex. This is similar to -i
641        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
642        using it. It makes it easier to run collections of tests with and without
643        study enabled, and thereby test pcre_study() more easily. All the standard
644        tests are now run with and without -s (but some patterns can be marked as
645        "never study" - see 20 below).
646    
647    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
648        restoration of the capturing data to the outer values was not happening
649        correctly.
650    
651    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
652        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
653        pattern had matched an empty string, and so incorrectly returned a no
654        match.
655    
656    17. There was optimizing code for the last branch of non-capturing parentheses,
657        and also for the obeyed branch of a conditional subexpression, which used
658        tail recursion to cut down on stack usage. Unfortunately, now that there is
659        the possibility of (*THEN) occurring in these branches, tail recursion is
660        no longer possible because the return has to be checked for (*THEN). These
661        two optimizations have therefore been removed. [But see 8.20/11 above.]
662    
663    18. If a pattern containing \R was studied, it was assumed that \R always
664        matched two bytes, thus causing the minimum subject length to be
665        incorrectly computed because \R can also match just one byte.
666    
667    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
668        was incorrectly computed.
669    
670    20. If /S is present twice on a test pattern in pcretest input, it now
671        *disables* studying, thereby overriding the use of -s on the command line
672        (see 14 above). This is necessary for one or two tests to keep the output
673        identical in both cases.
674    
675    21. When (*ACCEPT) was used in an assertion that matched an empty string and
676        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
677    
678    22. When an atomic group that contained a capturing parenthesis was
679        successfully matched, but the branch in which it appeared failed, the
680        capturing was not being forgotten if a higher numbered group was later
681        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
682        group 1 to "a", when in fact it should be unset. This applied to multi-
683        branched capturing and non-capturing groups, repeated or not, and also to
684        positive assertions (capturing in negative assertions does not happen
685        in PCRE) and also to nested atomic groups.
686    
687    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
688        subject after a captured substring, to make it easier to tell which of a
689        number of identical substrings has been captured.
690    
691    24. The way atomic groups are processed by pcre_exec() has been changed so that
692        if they are repeated, backtracking one repetition now resets captured
693        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
694        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
695        "aaa". Previously, it would have been "a". As part of this code
696        refactoring, the way recursive calls are handled has also been changed.
697    
698    25. If an assertion condition captured any substrings, they were not passed
699        back unless some other capturing happened later. For example, if
700        (?(?=(a))a) was matched against "a", no capturing was returned.
701    
702    26. When studying a pattern that contained subroutine calls or assertions,
703        the code for finding the minimum length of a possible match was handling
704        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
705        group 1 called group 2 while simultaneously a separate group 2 called group
706        1). A stack overflow occurred in this case. I have fixed this by limiting
707        the recursion depth to 10.
708    
709    27. Updated RunTest.bat in the distribution to the version supplied by Tom
710        Fortmann. This supports explicit test numbers on the command line, and has
711        argument validation and error reporting.
712    
713    28. An instance of \X with an unlimited repeat could fail if at any point the
714        first character it looked at was a mark character.
715    
716    29. Some minor code refactoring concerning Unicode properties and scripts
717        should reduce the stack requirement of match() slightly.
718    
719    30. Added the '=' option to pcretest to check the setting of unused capturing
720        slots at the end of the pattern, which are documented as being -1, but are
721        not included in the return count.
722    
723    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
724        compiled something random. Now it gives a compile-time error (as does
725        Perl).
726    
727    32. A *MARK encountered during the processing of a positive assertion is now
728        recorded and passed back (compatible with Perl).
729    
730    33. If --only-matching or --colour was set on a pcregrep call whose pattern
731        had alternative anchored branches, the search for a second match in a line
732        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
733        matched the line "0102" twice. The same bug affected patterns that started
734        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
735        twice.
736    
737    34. Previously, PCRE did not allow quantification of assertions. However, Perl
738        does, and because of capturing effects, quantifying parenthesized
739        assertions may at times be useful. Quantifiers are now allowed for
740        parenthesized assertions.
741    
742    35. A minor code tidy in pcre_compile() when checking options for \R usage.
743    
744    36. \g was being checked for fancy things in a character class, when it should
745        just be a literal "g".
746    
747    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
748        appearance of a nested POSIX class supersedes an apparent external class.
749        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
750        unescaped square brackets may also appear as part of class names. For
751        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
752        more like Perl. (But see 8.20/1 above.)
753    
754    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
755        was because it thought it was \N{name}, which is not supported).
756    
757    39. Add minix to OS list not supporting the -S option in pcretest.
758    
759    40. PCRE tries to detect cases of infinite recursion at compile time, but it
760        cannot analyze patterns in sufficient detail to catch mutual recursions
761        such as ((?1))((?2)). There is now a runtime test that gives an error if a
762        subgroup is called recursively as a subpattern for a second time at the
763        same position in the subject string. In previous releases this might have
764        been caught by the recursion limit, or it might have run out of stack.
765    
766    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
767        happen only once. PCRE was, however incorrectly giving a compile time error
768        "recursive call could loop indefinitely" because it cannot analyze the
769        pattern in sufficient detail. The compile time test no longer happens when
770        PCRE is compiling a conditional subpattern, but actual runaway loops are
771        now caught at runtime (see 40 above).
772    
773    42. It seems that Perl allows any characters other than a closing parenthesis
774        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
775        has been changed to be the same.
776    
777    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
778        as not to get warnings when autogen.sh is called. Also changed
779        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
780    
781    44. To help people who use pcregrep to scan files containing exceedingly long
782        lines, the following changes have been made:
783    
784        (a) The default value of the buffer size parameter has been increased from
785            8K to 20K. (The actual buffer used is three times this size.)
786    
787        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
788            PCRE is built.
789    
790        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
791            to be set at run time.
792    
793        (d) Numerical values in pcregrep options can be followed by K or M, for
794            example --buffer-size=50K.
795    
796        (e) If a line being scanned overflows pcregrep's buffer, an error is now
797            given and the return code is set to 2.
798    
799    45. Add a pointer to the latest mark to the callout data block.
800    
801    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
802        partial match of an empty string instead of no match. This was specific to
803        the use of ".".
804    
805    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
806        complete match instead of a partial match. This bug was dependent on both
807        the PCRE_UTF8 and PCRE_DOTALL options being set.
808    
809    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
810        starting byte set, because \b was not being ignored.
811    
812    
813    Version 8.12 15-Jan-2011
814    ------------------------
815    
816    1.  Fixed some typos in the markup of the man pages, and wrote a script that
817        checks for such things as part of the documentation building process.
818    
819    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
820        --match-limit and --recursion-limit options (added for 8.11). In
821        particular, this made one of the standard tests fail. (The integer value
822        went into the wrong half of a long int.)
823    
824    3.  If the --colour option was given to pcregrep with -v (invert match), it
825        did strange things, either producing crazy output, or crashing. It should,
826        of course, ignore a request for colour when reporting lines that do not
827        match.
828    
829    4.  Another pcregrep bug caused similar problems if --colour was specified with
830        -M (multiline) and the pattern match finished with a line ending.
831    
832    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
833        matched in multiline mode, the following line was shown as part of the
834        match. This seems wrong, so I have changed it.
835    
836    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
837        the check for further matches in the same line (so they could be coloured)
838        to overrun the end of the current line. If another match was found, it was
839        incorrectly shown (and then shown again when found in the next line).
840    
841    7.  If pcregrep was compiled under Windows, there was a reference to the
842        function pcregrep_exit() before it was defined. I am assuming this was
843        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
844        reported by a user. I've moved the definition above the reference.
845    
846    
847    Version 8.11 10-Dec-2010
848    ------------------------
849    
850    1.  (*THEN) was not working properly if there were untried alternatives prior
851        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
852        backtracked to try for "b" instead of moving to the next alternative branch
853        at the same level (in this case, to look for "c"). The Perl documentation
854        is clear that when (*THEN) is backtracked onto, it goes to the "next
855        alternative in the innermost enclosing group".
856    
857    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
858        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
859        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
860        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
861        (*THEN).
862    
863    3.  If \s appeared in a character class, it removed the VT character from
864        the class, even if it had been included by some previous item, for example
865        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
866        of \s, but is part of the POSIX "space" class.)
867    
868    4.  A partial match never returns an empty string (because you can always
869        match an empty string at the end of the subject); however the checking for
870        an empty string was starting at the "start of match" point. This has been
871        changed to the "earliest inspected character" point, because the returned
872        data for a partial match starts at this character. This means that, for
873        example, /(?<=abc)def/ gives a partial match for the subject "abc"
874        (previously it gave "no match").
875    
876    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
877        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
878        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
879        has an implication that the given string is incomplete (because a partial
880        match is preferred over a full match). For this reason, these items now
881        give a partial match in this situation. [Aside: previously, the one case
882        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
883        match rather than a full match, which was wrong by the old rules, but is
884        now correct.]
885    
886    6.  There was a bug in the handling of #-introduced comments, recognized when
887        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
888        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
889        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
890        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
891        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
892        places in pcre_compile().
893    
894    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
895        comments when looking ahead for named forward references to subpatterns,
896        the only newline sequence it recognized was NL. It now handles newlines
897        according to the set newline convention.
898    
899    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
900        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
901        cater for a lack of strerror(). These oversights have been fixed.
902    
903    9.  Added --match-limit and --recursion-limit to pcregrep.
904    
905    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
906    
907    11. When the -o option was used, pcregrep was setting a return code of 1, even
908        when matches were found, and --line-buffered was not being honoured.
909    
910    12. Added an optional parentheses number to the -o and --only-matching options
911        of pcregrep.
912    
913    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
914        can match an empty string. The code to do it in pcretest and pcredemo
915        needed fixing:
916    
917        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
918            only one byte after an empty string match just before CRLF (this case
919            just got forgotten; "any" and "anycrlf" were OK).
920    
921        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
922            mode when an empty string match preceded an ASCII character followed by
923            a non-ASCII character. (The code for advancing by one character rather
924            than one byte was nonsense.)
925    
926        (c) The pcredemo.c sample program did not have any code at all to handle
927            the cases when CRLF is a valid newline sequence.
928    
929    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
930        as a starting offset was within the subject string. There is now a new
931        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
932        negative or greater than the length of the string. In order to test this,
933        pcretest is extended to allow the setting of negative starting offsets.
934    
935    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
936        starting offset points to the beginning of a UTF-8 character was
937        unnecessarily clumsy. I tidied it up.
938    
939    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
940        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
941    
942    17. Nobody had reported that the --include_dir option, which was added in
943        release 7.7 should have been called --include-dir (hyphen, not underscore)
944        for compatibility with GNU grep. I have changed it to --include-dir, but
945        left --include_dir as an undocumented synonym, and the same for
946        --exclude-dir, though that is not available in GNU grep, at least as of
947        release 2.5.4.
948    
949    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
950        characters from a string of bytes) have been redefined so as not to use
951        loops, in order to improve performance in some environments. At the same
952        time, I abstracted some of the common code into auxiliary macros to save
953        repetition (this should not affect the compiled code).
954    
955    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
956        compile-time error is now given if \c is not followed by an ASCII
957        character, that is, a byte less than 128. (In EBCDIC mode, the code is
958        different, and any byte value is allowed.)
959    
960    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
961        START_OPTIMIZE option, which is now allowed at compile time - but just
962        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
963        to pcregrep and other applications that have no direct access to PCRE
964        options. The new /Y option in pcretest sets this option when calling
965        pcre_compile().
966    
967    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
968        back references. Groups containing recursive back references were forced to
969        be atomic by that change, but in the case of named groups, the amount of
970        memory required was incorrectly computed, leading to "Failed: internal
971        error: code overflow". This has been fixed.
972    
973    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
974        pcretest.c, to avoid build problems in some Borland environments.
975    
976    
977    Version 8.10 25-Jun-2010
978    ------------------------
979    
980    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
981        THEN.
982    
983    2.  (*ACCEPT) was not working when inside an atomic group.
984    
985    3.  Inside a character class, \B is treated as a literal by default, but
986        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
987        causes the error). The code is unchanged, but I tidied the documentation.
988    
989    4.  Inside a character class, PCRE always treated \R and \X as literals,
990        whereas Perl faults them if its -w option is set. I have changed PCRE so
991        that it faults them when PCRE_EXTRA is set.
992    
993    5.  Added support for \N, which always matches any character other than
994        newline. (It is the same as "." when PCRE_DOTALL is not set.)
995    
996    6.  When compiling pcregrep with newer versions of gcc which may have
997        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
998        declared with attribute warn_unused_result" were given. Just casting the
999        result to (void) does not stop the warnings; a more elaborate fudge is
1000        needed. I've used a macro to implement this.
1001    
1002    7.  Minor change to pcretest.c to avoid a compiler warning.
1003    
1004    8.  Added four artifical Unicode properties to help with an option to make
1005        \s etc use properties (see next item). The new properties are: Xan
1006        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1007    
1008    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1009        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1010        this option. Modified pcretest to add /W to test this facility. Added
1011        REG_UCP to make it available via the POSIX interface.
1012    
1013    10. Added --line-buffered to pcregrep.
1014    
1015    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1016        studied, and the match started with a letter with a code point greater than
1017        127 whose first byte was different to the first byte of the other case of
1018        the letter, the other case of this starting letter was not recognized
1019        (#976).
1020    
1021    12. If a pattern that was studied started with a repeated Unicode property
1022        test, for example, \p{Nd}+, there was the theoretical possibility of
1023        setting up an incorrect bitmap of starting bytes, but fortunately it could
1024        not have actually happened in practice until change 8 above was made (it
1025        added property types that matched character-matching opcodes).
1026    
1027    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1028        possible starting bytes for non-anchored patterns.
1029    
1030    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1031        \R, and also a number of cases that involve Unicode properties, both
1032        explicit and implicit when PCRE_UCP is set.
1033    
1034    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1035        input, it could crash or give wrong results if characters with values
1036        greater than 0xc0 were present in the subject string. (Detail: it assumed
1037        UTF-8 input when processing these items.)
1038    
1039    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1040        size_t is 64-bit (#991).
1041    
1042    17. Added a check for running out of memory when PCRE is compiled with
1043        --disable-stack-for-recursion (#990).
1044    
1045    18. If the last data line in a file for pcretest does not have a newline on
1046        the end, a newline was missing in the output.
1047    
1048    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1049        less than 128) in its various bitmaps. However, there is a facility for
1050        generating tables according to the current locale when PCRE is compiled. It
1051        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1052        characters, are recognized by isspace() and therefore were getting set in
1053        these tables, and indeed these tables seem to approximate to ISO 8859. This
1054        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1055        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1056        which of course cannot start UTF-8 characters. I have changed the code so
1057        that only real ASCII characters (less than 128) and the correct starting
1058        bytes for UTF-8 encodings are set for characters greater than 127 when in
1059        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1060        altogether.)
1061    
1062    20. Added the /T option to pcretest so as to be able to run tests with non-
1063        standard character tables, thus making it possible to include the tests
1064        used for 19 above in the standard set of tests.
1065    
1066    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1067        reference to a subpattern the other side of a comment that contains an
1068        opening parenthesis caused either an internal compiling error, or a
1069        reference to the wrong subpattern.
1070    
1071    
1072    Version 8.02 19-Mar-2010
1073    ------------------------
1074    
1075    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1076    
1077    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1078        configured.
1079    
1080    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1081        original author of that file, following a query about its status.
1082    
1083    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1084        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1085    
1086    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1087        quantifier applied to a forward-referencing subroutine call, could compile
1088        incorrect code or give the error "internal error: previously-checked
1089        referenced subpattern not found".
1090    
1091    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1092        variables to point to external functions. For these systems, therefore,
1093        pcre_malloc etc. are now initialized to local functions that call the
1094        relevant global functions.
1095    
1096    7.  There were two entries missing in the vectors called coptable and poptable
1097        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1098        I've fixed the data, and added a kludgy way of testing at compile time that
1099        the lengths are correct (equal to the number of opcodes).
1100    
1101    8.  Following on from 7, I added a similar kludge to check the length of the
1102        eint vector in pcreposix.c.
1103    
1104    9.  Error texts for pcre_compile() are held as one long string to avoid too
1105        much relocation at load time. To find a text, the string is searched,
1106        counting zeros. There was no check for running off the end of the string,
1107        which could happen if a new error number was added without updating the
1108        string.
1109    
1110    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1111    
1112    11. \K was not working if it appeared in an atomic group or in a group that
1113        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1114        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1115        the assertion is positive, but not if it is negative.
1116    
1117    12. Change 11 fortuitously reduced the size of the stack frame used in the
1118        "match()" function of pcre_exec.c by one pointer. Forthcoming
1119        implementation of support for (*MARK) will need an extra pointer on the
1120        stack; I have reserved it now, so that the stack frame size does not
1121        decrease.
1122    
1123    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1124        item in branch that calls a recursion is a subroutine call - as in the
1125        second branch in the above example - was incorrectly given the compile-
1126        time error "recursive call could loop indefinitely" because pcre_compile()
1127        was not correctly checking the subroutine for matching a non-empty string.
1128    
1129    14. The checks for overrunning compiling workspace could trigger after an
1130        overrun had occurred. This is a "should never occur" error, but it can be
1131        triggered by pathological patterns such as hundreds of nested parentheses.
1132        The checks now trigger 100 bytes before the end of the workspace.
1133    
1134    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1135    
1136    
1137    Version 8.01 19-Jan-2010
1138    ------------------------
1139    
1140    1.  If a pattern contained a conditional subpattern with only one branch (in
1141        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1142        computed the wrong minimum data length (which is of course zero for such
1143        subpatterns). This could cause incorrect "no match" results.
1144    
1145    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1146        the pattern is reset in the first branch, pcre_compile() failed with
1147        "internal error: code overflow at offset...". This happened only when
1148        the reset was to the original external option setting. (An optimization
1149        abstracts leading options settings into an external setting, which was the
1150        cause of this.)
1151    
1152    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1153        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1154        assertion pattern did not match (meaning that the assertion was true), it
1155        was incorrectly treated as false if the SKIP had been reached during the
1156        matching. This also applied to assertions used as conditions.
1157    
1158    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1159        assertion subpattern, including such a pattern used as a condition,
1160        unpredictable results occurred, instead of the error return
1161        PCRE_ERROR_DFA_UITEM.
1162    
1163    5.  The C++ GlobalReplace function was not working like Perl for the special
1164        situation when an empty string is matched. It now does the fancy magic
1165        stuff that is necessary.
1166    
1167    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1168        removed. (These were left over from very, very early versions of PCRE.)
1169    
1170    7.  Some cosmetic changes to the code to make life easier when compiling it
1171        as part of something else:
1172    
1173        (a) Change DEBUG to PCRE_DEBUG.
1174    
1175        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1176            called "current" as "current_branch", to prevent a collision with the
1177            Linux macro when compiled as a kernel module.
1178    
1179        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1180            prevent a collision with the Linux macro when compiled as a kernel
1181            module.
1182    
1183    8.  In pcre_compile() there are some checks for integer overflows that used to
1184        cast potentially large values to (double). This has been changed to that
1185        when building, a check for int64_t is made, and if it is found, it is used
1186        instead, thus avoiding the use of floating point arithmetic. (There is no
1187        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1188        double.
1189    
1190    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1191        2005 (difference between two addresses compared to an unsigned value).
1192    
1193    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1194        custom one, because of the following reported problem in Windows:
1195    
1196          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1197              under Win32.
1198          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1199              therefore missing the function definition.
1200          - The compiler thus generates a "C" signature for the test function.
1201          - The linker fails to find the "C" function.
1202          - PCRE fails to configure if asked to do so against libbz2.
1203    
1204    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1205        messages were output:
1206    
1207          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1208          rerunning libtoolize, to keep the correct libtool macros in-tree.
1209          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1210    
1211        I have done both of these things.
1212    
1213    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1214        most of the time, it *can* run out if it is given a pattern that contains a
1215        runaway infinite recursion. I updated the discussion in the pcrestack man
1216        page.
1217    
1218    13. Now that we have gone to the x.xx style of version numbers, the minor
1219        version may start with zero. Using 08 or 09 is a bad idea because users
1220        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1221        interpreted as invalid octal numbers. I've updated the previous comment in
1222        configure.ac, and also added a check that gives an error if 08 or 09 are
1223        used.
1224    
1225    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1226        causing partial matching to fail when the end of the subject matched \W
1227        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1228    
1229    15. There were some discrepancies between the declarations in pcre_internal.h
1230        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1231        their definitions. The declarations used "const uschar *" and the
1232        definitions used USPTR. Even though USPTR is normally defined as "const
1233        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1234        reported that: "This difference in casting confuses some C++ compilers, for
1235        example, SunCC recognizes above declarations as different functions and
1236        generates broken code for hbpcre." I have changed the declarations to use
1237        USPTR.
1238    
1239    16. GNU libtool is named differently on some systems. The autogen.sh script now
1240        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1241        (FreeBSD).
1242    
1243    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1244        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1245        comment: "Figure out how to create a longlong from a string: strtoll and
1246        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1247        instance, but it only takes 2 args instead of 3!"
1248    
1249    18. A subtle bug concerned with back references has been fixed by a change of
1250        specification, with a corresponding code fix. A pattern such as
1251        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1252        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1253        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1254        same bug. Such groups have to be quantified to be useful, or contained
1255        inside another quantified group. (If there's no repetition, the reference
1256        can never match.) The problem arises because, having left the group and
1257        moved on to the rest of the pattern, a later failure that backtracks into
1258        the group uses the captured value from the final iteration of the group
1259        rather than the correct earlier one. I have fixed this in PCRE by forcing
1260        any group that contains a reference to itself to be an atomic group; that
1261        is, there cannot be any backtracking into it once it has completed. This is
1262        similar to recursive and subroutine calls.
1263    
1264    
1265    Version 8.00 19-Oct-09
1266    ----------------------
1267    
1268    1.  The table for translating pcre_compile() error codes into POSIX error codes
1269        was out-of-date, and there was no check on the pcre_compile() error code
1270        being within the table. This could lead to an OK return being given in
1271        error.
1272    
1273    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1274        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1275        in a Windows environment.
1276    
1277    3.  The pcregrep --count option prints the count for each file even when it is
1278        zero, as does GNU grep. However, pcregrep was also printing all files when
1279        --files-with-matches was added. Now, when both options are given, it prints
1280        counts only for those files that have at least one match. (GNU grep just
1281        prints the file name in this circumstance, but including the count seems
1282        more useful - otherwise, why use --count?) Also ensured that the
1283        combination -clh just lists non-zero counts, with no names.
1284    
1285    4.  The long form of the pcregrep -F option was incorrectly implemented as
1286        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1287        but it seems right to fix it, and I didn't think it was worth preserving
1288        the old behaviour.
1289    
1290    5.  The command line items --regex=pattern and --regexp=pattern were not
1291        recognized by pcregrep, which required --regex pattern or --regexp pattern
1292        (with a space rather than an '='). The man page documented the '=' forms,
1293        which are compatible with GNU grep; these now work.
1294    
1295    6.  No libpcreposix.pc file was created for pkg-config; there was just
1296        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1297    
1298    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1299        when UCP support is not needed, by modifying the Python script that
1300        generates it from Unicode data files. This should not matter if the module
1301        is correctly used as a library, but I received one complaint about 50K of
1302        unwanted data. My guess is that the person linked everything into his
1303        program rather than using a library. Anyway, it does no harm.
1304    
1305    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1306        was a minimum greater than 1 for a wide character in a possessive
1307        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1308        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1309        character. Chaos in the form of incorrect output or a compiling loop could
1310        result.
1311    
1312    9.  The restrictions on what a pattern can contain when partial matching is
1313        requested for pcre_exec() have been removed. All patterns can now be
1314        partially matched by this function. In addition, if there are at least two
1315        slots in the offset vector, the offset of the earliest inspected character
1316        for the match and the offset of the end of the subject are set in them when
1317        PCRE_ERROR_PARTIAL is returned.
1318    
1319    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1320        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1321        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1322        and may be more useful for multi-segment matching.
1323    
1324    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1325        used to be given if ever the end of the subject was reached; now it is
1326        given only if matching could not proceed because another character was
1327        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1328        string "Z", which now yields "no match" instead of "partial match". In the
1329        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1330        final character ended with (*FAIL).
1331    
1332    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1333        if the pattern had a "must contain" character that was already found in the
1334        earlier partial match, unless partial matching was again requested. For
1335        example, with the pattern /dog.(body)?/, the "must contain" character is
1336        "g". If the first part-match was for the string "dog", restarting with
1337        "sbody" failed. This bug has been fixed.
1338    
1339    13. The string returned by pcre_dfa_exec() after a partial match has been
1340        changed so that it starts at the first inspected character rather than the
1341        first character of the match. This makes a difference only if the pattern
1342        starts with a lookbehind assertion or \b or \B (\K is not supported by
1343        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1344        matching functions compatible, and I think it's the right thing to do.
1345    
1346    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1347        so that the demonstration program is easily available in environments where
1348        PCRE has not been installed from source.
1349    
1350    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1351        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1352        library.
1353    
1354    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1355        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1356        is not the first non-POSIX option to be added. Clearly some people find
1357        these options useful.
1358    
1359    17. If a caller to the POSIX matching function regexec() passes a non-zero
1360        value for nmatch with a NULL value for pmatch, the value of
1361        nmatch is forced to zero.
1362    
1363    18. RunGrepTest did not have a test for the availability of the -u option of
1364        the diff command, as RunTest does. It now checks in the same way as
1365        RunTest, and also checks for the -b option.
1366    
1367    19. If an odd number of negated classes containing just a single character
1368        interposed, within parentheses, between a forward reference to a named
1369        subpattern and the definition of the subpattern, compilation crashed with
1370        an internal error, complaining that it could not find the referenced
1371        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1372        [The bug was that it was starting one character too far in when skipping
1373        over the character class, thus treating the ] as data rather than
1374        terminating the class. This meant it could skip too much.]
1375    
1376    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1377        /g option in pcretest when the pattern contains \K, which makes it possible
1378        to have an empty string match not at the start, even when the pattern is
1379        anchored. Updated pcretest and pcredemo to use this option.
1380    
1381    21. If the maximum number of capturing subpatterns in a recursion was greater
1382        than the maximum at the outer level, the higher number was returned, but
1383        with unset values at the outer level. The correct (outer level) value is
1384        now given.
1385    
1386    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1387        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1388        make it do so. The string so far is captured, making this feature
1389        compatible with Perl.
1390    
1391    23. The tests have been re-organized, adding tests 11 and 12, to make it
1392        possible to check the Perl 5.10 features against Perl 5.10.
1393    
1394    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1395        pattern matches a fixed length string. PCRE did not allow this; now it
1396        does. Neither allows recursion.
1397    
1398    25. I finally figured out how to implement a request to provide the minimum
1399        length of subject string that was needed in order to match a given pattern.
1400        (It was back references and recursion that I had previously got hung up
1401        on.) This code has now been added to pcre_study(); it finds a lower bound
1402        to the length of subject needed. It is not necessarily the greatest lower
1403        bound, but using it to avoid searching strings that are too short does give
1404        some useful speed-ups. The value is available to calling programs via
1405        pcre_fullinfo().
1406    
1407    26. While implementing 25, I discovered to my embarrassment that pcretest had
1408        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1409        study optimizations had never been tested with that matching function.
1410        Oops. What is worse, even when it was passed study data, there was a bug in
1411        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1412        were also very few tests of studied patterns with pcre_dfa_exec().
1413    
1414    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1415        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1416        on the other side of the coin, they are no longer allowed to have different
1417        names, because these cannot be distinguished in PCRE, and this has caused
1418        confusion. (This is a difference from Perl.)
1419    
1420    28. When duplicate subpattern names are present (necessarily with different
1421        numbers, as required by 27 above), and a test is made by name in a
1422        conditional pattern, either for a subpattern having been matched, or for
1423        recursion in such a pattern, all the associated numbered subpatterns are
1424        tested, and the overall condition is true if the condition is true for any
1425        one of them. This is the way Perl works, and is also more like the way
1426        testing by number works.
1427    
1428    
1429    Version 7.9 11-Apr-09
1430    ---------------------
1431    
1432    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1433        (pcretest), all targets were linked against these libraries. This included
1434        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1435        libraries. This caused unwanted dependencies to be created. This problem
1436        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1437        pcretest is linked with readline.
1438    
1439    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1440        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1441        moved outside it again, because FALSE and TRUE are already defined in AIX,
1442        but BOOL is not.
1443    
1444    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1445        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1446    
1447    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1448        hyphens) following file names and line numbers when outputting matching
1449        lines. This is not true; no spaces are inserted. I have also clarified the
1450        wording for the --colour (or --color) option.
1451    
1452    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1453        was not coloured; this is different to GNU grep, so I have changed it to be
1454        the same.
1455    
1456    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1457        each matching line was coloured. Now it goes on to look for further matches
1458        of any of the test patterns, which is the same behaviour as GNU grep.
1459    
1460    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1461        doesn't make sense to accept an empty string match in pcregrep, so I have
1462        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1463        seems to be how GNU grep behaves.
1464    
1465    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1466        start or after a newline", because the conditional assertion was not being
1467        correctly handled. The rule now is that both the assertion and what follows
1468        in the first alternative must satisfy the test.
1469    
1470    9.  If auto-callout was enabled in a pattern with a conditional group whose
1471        condition was an assertion, PCRE could crash during matching, both with
1472        pcre_exec() and pcre_dfa_exec().
1473    
1474    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1475        used for matching.
1476    
1477    11. Unicode property support in character classes was not working for
1478        characters (bytes) greater than 127 when not in UTF-8 mode.
1479    
1480    12. Added the -M command line option to pcretest.
1481    
1482    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1483    
1484    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1485    
1486    16. Added comments and documentation about mis-use of no_arg in the C++
1487        wrapper.
1488    
1489    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1490        from Martin Jerabek that uses macro names for all relevant character and
1491        string constants.
1492    
1493    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1494        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1495        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1496        these, but not everybody uses configure.
1497    
1498    19. A conditional group that had only one branch was not being correctly
1499        recognized as an item that could match an empty string. This meant that an
1500        enclosing group might also not be so recognized, causing infinite looping
1501        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1502        with the subject "ab", where knowledge that the repeated group can match
1503        nothing is needed in order to break the loop.
1504    
1505    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1506        exec(), but without supplying a callout function, matching went wrong.
1507    
1508    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1509        leak if the size of the offset vector was greater than 30. When the vector
1510        is smaller, the saved offsets during recursion go onto a local stack
1511        vector, but for larger vectors malloc() is used. It was failing to free
1512        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1513        error, in fact).
1514    
1515    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1516        heapframe that is used only when UTF-8 support is enabled. This caused no
1517        problem, but was untidy.
1518    
1519    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1520        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1521        included within another project.
1522    
1523    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1524        slightly modified by me:
1525    
1526          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1527              not building pcregrep.
1528    
1529          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1530              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1531    
1532    25. Forward references, both numeric and by name, in patterns that made use of
1533        duplicate group numbers, could behave incorrectly or give incorrect errors,
1534        because when scanning forward to find the reference group, PCRE was not
1535        taking into account the duplicate group numbers. A pattern such as
1536        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1537    
1538    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1539        the feature of a custom pointer more persuasive (as requested by a user).
1540    
1541    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1542        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1543        pre-defined.
1544    
1545    28. Added support for (*UTF8) at the start of a pattern.
1546    
1547    29. Arrange for flags added by the "release type" setting in CMake to be shown
1548        in the configuration summary.
1549    
1550    
1551    Version 7.8 05-Sep-08
1552  ---------------------  ---------------------
1553    
1554  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
1555      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1556      stage table and inline lookup instead of a function, giving speed ups of 2      stage table and inline lookup instead of a function, giving speed ups of 2
1557      to 5 times on some simple patterns that I tested. Permission was given to      to 5 times on some simple patterns that I tested. Permission was given to
1558      distribute the MultiStage2.py script that generates the tables (it's not in      distribute the MultiStage2.py script that generates the tables (it's not in
1559      the tarball, but is in the Subversion repository).      the tarball, but is in the Subversion repository).
1560    
1561    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1562        scripts.
1563    
1564    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1565        a group with a zero qualifier. The result of the study could be incorrect,
1566        or the function might crash, depending on the pattern.
1567    
1568    4.  Caseless matching was not working for non-ASCII characters in back
1569        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1570        It now works when Unicode Property Support is available.
1571    
1572    5.  In pcretest, an escape such as \x{de} in the data was always generating
1573        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1574        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1575        truncation.
1576    
1577    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1578    
1579    7.  Added two (int) casts to pcregrep when printing the difference of two
1580        pointers, in case they are 64-bit values.
1581    
1582    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1583        test 2 if it fails.
1584    
1585    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1586        and a #define of that name to empty if it is not externally set. This is to
1587        allow users of MSVC to set it if necessary.
1588    
1589    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1590        the convenience functions in the pcre_get.c source file.
1591    
1592    11. An option change at the start of a pattern that had top-level alternatives
1593        could cause overwriting and/or a crash. This command provoked a crash in
1594        some environments:
1595    
1596          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1597    
1598        This potential security problem was recorded as CVE-2008-2371.
1599    
1600    12. For a pattern where the match had to start at the beginning or immediately
1601        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1602        pcre_dfa_exec() could read past the end of the passed subject if there was
1603        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1604        pcretest so that it places the subject at the end of its malloc-ed buffer.
1605    
1606    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1607        exec() might read past the end of the data buffer in UTF-8 mode.
1608    
1609    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1610        the data contained the byte 0x85 as part of a UTF-8 character within its
1611        first line. This applied both to normal and DFA matching.
1612    
1613    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1614        /^[^d]*?$/8 failed to match "abc".
1615    
1616    16. Added a missing copyright notice to pcrecpp_internal.h.
1617    
1618    17. Make it more clear in the documentation that values returned from
1619        pcre_exec() in ovector are byte offsets, not character counts.
1620    
1621    18. Tidied a few places to stop certain compilers from issuing warnings.
1622    
1623    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1624        supplied by Stefan Weber. I made a further small update for 7.8 because
1625        there is a change of source arrangements: the pcre_searchfuncs.c module is
1626        replaced by pcre_ucd.c.
1627    
1628    
1629  Version 7.7 07-May-08  Version 7.7 07-May-08

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