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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.5 12-Nov-07  Version 8.33 xx-xxxx-201x
5    -------------------------
6    
7    1.  Added 'U' to some constants that are compared to unsigned integers, to
8        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
9        variables that are added to signed variables, to ensure the result is
10        signed and can be negated.
11    
12    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
13        CMake config files.
14    
15    3.  Revise the creation of config.h.generic so that all boolean macros are
16        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
17        overriding via -D on the command line possible.
18    
19    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
20        to unsigned int is reported to make a quite noticeable speed difference in
21        a specific Windows environment. Testing on Linux did also appear to show
22        some benefit (and it is clearly not harmful). Also fixed the definition of
23        Xop which should be unsigned.
24    
25    5.  Related to (4), changing the definition of the intermediate variable cc
26        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
27        improvements.
28    
29    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
30        unnecessary spaces.
31    
32    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
33        and later.
34    
35    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
36    
37    9.  Optimizing fast_forward_start_bits in JIT.
38    
39    10. Adding experimental support for callouts in JIT, and fixing some
40        issues revealed during this work. Namely:
41    
42        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
43    
44        (b) Minimum length was not checked before the matching is started.
45    
46    11. The value of capture_last that is passed to callouts was incorrect in some
47        cases when there was a capture on one path that was subsequently abandoned
48        after a backtrack. Also, the capture_last value is now reset after a
49        recursion, since all captures are also reset in this case.
50    
51    12. The interpreter no longer returns the "too many substrings" error in the
52        case when an overflowing capture is in a branch that is subsequently
53        abandoned after a backtrack.
54    
55    13. In the pathological case when an offset vector of size 2 is used, pcretest
56        now prints out the matched string after a yield of 0 or 1.
57    
58    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
59        Only supported by the JIT compiler at the moment.
60    
61    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
62    
63    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
64        offset of the starting point of the matching process, provided the offsets
65        vector is large enough.
66    
67    17. The \A escape now records a lookbehind value of 1, though its execution
68        does not actually inspect the previous character. This is to ensure that,
69        in partial multi-segment matching, at least one character from the old
70        segment is retained when a new segment is processed. Otherwise, if there
71        are no lookbehinds in the pattern, \A might match incorrectly at the start
72        of a new segment.
73    
74    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
75    
76    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
77        gives some modest performance improvement in 8-bit mode.
78    
79    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
80        be expressed in certain programming languages using Universal Character
81        Names.
82    
83    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
84        which points out that "non characters" are not "characters that may not
85        appear in Unicode strings" but rather "characters that are reserved for
86        internal use and have only local meaning".
87    
88    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
89        there was a conditional group that depended on an assertion, if the
90        assertion was false, the callout that immediately followed the alternation
91        in the condition was skipped when pcre_exec() was used for matching.
92    
93    23. Allow an explicit callout to be inserted before an assertion that is the
94        condition for a conditional group, for compatibility with automatic
95        callouts, which always insert a callout at this point.
96    
97    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
98        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
99    
100    25. (*PRUNE) is now supported by the JIT compiler.
101    
102    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
103    
104    27. Fix the case where there are two or more SKIPs with arguments that may be
105        ignored.
106    
107    28. Experimental support of (*SKIP) backtracking verb in the JIT compiler.
108    
109    29. Experimental support of (*THEN) backtracking verb in the JIT compiler.
110    
111    30. Update RunTest with additional test selector options.
112    
113    31. The way PCRE handles backtracking verbs has been changed in to ways.
114    
115        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
116        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
117        backtracking. In some cases this makes it more Perl-compatible, but Perl's
118        rather obscure rules do not always do the same thing.
119    
120        (2) Previously, backtracking verbs were confined within assertions. This is
121        no longer the case. Again, this sometimes improves Perl compatibility, and
122        sometimes does not.
123    
124    
125    Version 8.32 30-November-2012
126    -----------------------------
127    
128    1.  Improved JIT compiler optimizations for first character search and single
129        character iterators.
130    
131    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
132        Patch by Daniel Richard G.
133    
134    3.  Single character iterator optimizations in the JIT compiler.
135    
136    4.  Improved JIT compiler optimizations for character ranges.
137    
138    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
139        Reported by Giuseppe D'Angelo.
140    
141    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
142        of a line, was being set incorrectly in cases where .* appeared inside
143        atomic brackets at the start of a pattern, or where there was a subsequent
144        *PRUNE or *SKIP.
145    
146    7.  Improved instruction cache flush for POWER/PowerPC.
147        Patch by Daniel Richard G.
148    
149    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
150        grep:
151    
152        (a) There is now no limit to the number of patterns to be matched.
153    
154        (b) An error is given if a pattern is too long.
155    
156        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
157            are now supported.
158    
159        (d) --exclude-from and --include-from (multiple use) have been added.
160    
161        (e) Exclusions and inclusions now apply to all files and directories, not
162            just to those obtained from scanning a directory recursively.
163    
164        (f) Multiple uses of -f and --file-list are now supported.
165    
166        (g) In a Windows environment, the default for -d has been changed from
167            "read" (the GNU grep default) to "skip", because otherwise the presence
168            of a directory in the file list provokes an error.
169    
170        (h) The documentation has been revised and clarified in places.
171    
172    9.  Improve the matching speed of capturing brackets.
173    
174    10. Changed the meaning of \X so that it now matches a Unicode extended
175        grapheme cluster.
176    
177    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
178        out POSIX threads when JIT support is configured.
179    
180    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
181    
182    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
183        structure could go wrong in environments where size_t is not the same size
184        as int.
185    
186    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
187        set.
188    
189    15. The EBCDIC support had decayed; later updates to the code had included
190        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
191        general tidy up of EBCDIC-related issues, and the documentation was also
192        not quite right. There is now a test that can be run on ASCII systems to
193        check some of the EBCDIC-related things (but is it not a full test).
194    
195    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
196        in a small tidy to the code.
197    
198    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
199    
200    18. If the --only-matching (-o) option in pcregrep is specified multiple
201        times, each one causes appropriate output. For example, -o1 -o2 outputs the
202        substrings matched by the 1st and 2nd capturing parentheses. A separating
203        string can be specified by --om-separator (default empty).
204    
205    19. Improving the first n character searches.
206    
207    20. Turn case lists for horizontal and vertical white space into macros so that
208        they are defined only once.
209    
210    21. This set of changes together give more compatible Unicode case-folding
211        behaviour for characters that have more than one other case when UCP
212        support is available.
213    
214        (a) The Unicode property table now has offsets into a new table of sets of
215            three or more characters that are case-equivalent. The MultiStage2.py
216            script that generates these tables (the pcre_ucd.c file) now scans
217            CaseFolding.txt instead of UnicodeData.txt for character case
218            information.
219    
220        (b) The code for adding characters or ranges of characters to a character
221            class has been abstracted into a generalized function that also handles
222            case-independence. In UTF-mode with UCP support, this uses the new data
223            to handle characters with more than one other case.
224    
225        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
226            whose other case is greater than 256 are now correctly matched
227            caselessly. Previously, the high codepoint matched the low one, but not
228            vice versa.
229    
230        (d) The processing of \h, \H, \v, and \ in character classes now makes use
231            of the new class addition function, using character lists defined as
232            macros alongside the case definitions of 20 above.
233    
234        (e) Caseless back references now work with characters that have more than
235            one other case.
236    
237        (f) General caseless matching of characters with more than one other case
238            is supported.
239    
240    22. Unicode character properties were updated from Unicode 6.2.0
241    
242    23. Improved CMake support under Windows. Patch by Daniel Richard G.
243    
244    24. Add support for 32-bit character strings, and UTF-32
245    
246    25. Major JIT compiler update (code refactoring and bugfixing).
247        Experimental Sparc 32 support is added.
248    
249    26. Applied a modified version of Daniel Richard G's patch to create
250        pcre.h.generic and config.h.generic by "make" instead of in the
251        PrepareRelease script.
252    
253    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
254        pcre_compile.c when checking for a zero character.
255    
256    28. Introducing a native interface for JIT. Through this interface, the compiled
257        machine code can be directly executed. The purpose of this interface is to
258        provide fast pattern matching, so several sanity checks are not performed.
259        However, feature tests are still performed. The new interface provides
260        1.4x speedup compared to the old one.
261    
262    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
263        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
264        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
265    
266    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
267        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
268        the "old" RFC 2279). Instead, it ended up passing a negative length to
269        pcre_exec().
270    
271    31. Add support for GCC's visibility feature to hide internal functions.
272    
273    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
274        "unknown -C option" after outputting 0 or 1.
275    
276    33. There is now support for generating a code coverage report for the test
277        suite in environments where gcc is the compiler and lcov is installed. This
278        is mainly for the benefit of the developers.
279    
280    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
281        unaddressable using valgrind annotations, allowing valgrind to detect
282        invalid memory accesses. This is mainly for the benefit of the developers.
283    
284    25. (*UTF) can now be used to start a pattern in any of the three libraries.
285    
286    26. Give configure error if --enable-cpp but no C++ compiler found.
287    
288    
289    Version 8.31 06-July-2012
290    -------------------------
291    
292    1.  Fixing a wrong JIT test case and some compiler warnings.
293    
294    2.  Removed a bashism from the RunTest script.
295    
296    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
297        to unsigned type, result still unsigned" that was given by an MS compiler
298        on encountering the code "-sizeof(xxx)".
299    
300    4.  Partial matching support is added to the JIT compiler.
301    
302    5.  Fixed several bugs concerned with partial matching of items that consist
303        of more than one character:
304    
305        (a) /^(..)\1/ did not partially match "aba" because checking references was
306            done on an "all or nothing" basis. This also applied to repeated
307            references.
308    
309        (b) \R did not give a hard partial match if \r was found at the end of the
310            subject.
311    
312        (c) \X did not give a hard partial match after matching one or more
313            characters at the end of the subject.
314    
315        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
316            a partial match for the string "\r".
317    
318        (e) When newline was set to CRLF, the metacharacter "." did not recognize
319            a partial match for a CR character at the end of the subject string.
320    
321    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
322        running pcretest, the text "(JIT)" added to the output whenever JIT is
323        actually used to run the match.
324    
325    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
326        or /S+[+] with a digit between 1 and 7.
327    
328    8.  OP_NOT now supports any UTF character not just single-byte ones.
329    
330    9.  (*MARK) control verb is now supported by the JIT compiler.
331    
332    10. The command "./RunTest list" lists the available tests without actually
333        running any of them. (Because I keep forgetting what they all are.)
334    
335    11. Add PCRE_INFO_MAXLOOKBEHIND.
336    
337    12. Applied a (slightly modified) user-supplied patch that improves performance
338        when the heap is used for recursion (compiled with --disable-stack-for-
339        recursion). Instead of malloc and free for each heap frame each time a
340        logical recursion happens, frames are retained on a chain and re-used where
341        possible. This sometimes gives as much as 30% improvement.
342    
343    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
344        call.
345    
346    14. As documented, (*COMMIT) is now confined to within a positive assertion.
347    
348    15. It is now possible to link pcretest with libedit as an alternative to
349        libreadline.
350    
351    16. (*COMMIT) control verb is now supported by the JIT compiler.
352    
353    17. The Unicode data tables have been updated to Unicode 6.1.0.
354    
355    18. Added --file-list option to pcregrep.
356    
357    19. Added binary file support to pcregrep, including the -a, --binary-files,
358        -I, and --text options.
359    
360    20. The madvise function is renamed for posix_madvise for QNX compatibility
361        reasons. Fixed by Giuseppe D'Angelo.
362    
363    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
364    
365    22. Changed the option for creating symbolic links for 16-bit man pages from
366        -s to -sf so that re-installing does not cause issues.
367    
368    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
369    
370    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
371        matches in certain environments (the workspace was not being correctly
372        retained). Also added to pcre_dfa_exec() a simple plausibility check on
373        some of the workspace data at the beginning of a restart.
374    
375    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
376        was not doing so when it should - probably a typo introduced by SVN 528
377        (change 8.10/14).
378    
379    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
380        \w+ when the character tables indicated that \x{c4} was a word character.
381        There were several related cases, all because the tests for doing a table
382        lookup were testing for characters less than 127 instead of 255.
383    
384    27. If a pattern contains capturing parentheses that are not used in a match,
385        their slots in the ovector are set to -1. For those that are higher than
386        any matched groups, this happens at the end of processing. In the case when
387        there were back references that the ovector was too small to contain
388        (causing temporary malloc'd memory to be used during matching), and the
389        highest capturing number was not used, memory off the end of the ovector
390        was incorrectly being set to -1. (It was using the size of the temporary
391        memory instead of the true size.)
392    
393    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
394        ovector size, it uses memory at the end of the block that it has got.
395    
396    29. Check for an overlong MARK name and give an error at compile time. The
397        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
398    
399    30. JIT compiler update.
400    
401    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
402        Rill for the patch.
403    
404    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
405    
406    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
407    
408    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
409        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
410        was enabled.
411    
412    35. Improve JIT code generation for greedy plus quantifier.
413    
414    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
415        1 to "aa" instead of to an empty string. The bug affected repeated groups
416        that could potentially match an empty string.
417    
418    37. Optimizing single character iterators in JIT.
419    
420    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
421        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
422        codepoints that are too big for the mode are faulted, and in a UTF mode,
423        disallowed codepoints are also faulted.
424    
425    39. If PCRE was compiled with UTF support, in three places in the DFA
426        matcher there was code that should only have been obeyed in UTF mode, but
427        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
428        processing when bytes with values greater than 127 were present. In 16-bit
429        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
430        both cases the values are those that cannot be the first data item in a UTF
431        character. The three items that might have provoked this were recursions,
432        possessively repeated groups, and atomic groups.
433    
434    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
435        and pcregrep, because some OS require shared objects to be explicitly
436        passed to ld, causing the link step to fail if they are not.
437    
438    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
439        mode, patterns that started with \h* or \R* might be incorrectly matched.
440    
441    
442    Version 8.30 04-February-2012
443    -----------------------------
444    
445    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
446        name is defined in ctype.h.
447    
448    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
449        only in quite long subpatterns.
450    
451    3.  Removed the function pcre_info(), which has been obsolete and deprecated
452        since it was replaced by pcre_fullinfo() in February 2000.
453    
454    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
455        match a (*MARK), and the match failed at the start of the subject, a
456        reference to memory before the start of the subject could occur. This bug
457        was introduced by fix 17 of release 8.21.
458    
459    5.  A reference to an unset group with zero minimum repetition was giving
460        totally wrong answers (in non-JavaScript-compatibility mode). For example,
461        /(another)?(\1?)test/ matched against "hello world test". This bug was
462        introduced in release 8.13.
463    
464    6.  Add support for 16-bit character strings (a large amount of work involving
465        many changes and refactorings).
466    
467    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
468        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
469        from a file.
470    
471    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
472        rounding is not applied in this particular case).
473    
474    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
475        if they appear, or are escaped, in patterns.
476    
477    10. Get rid of a number of -Wunused-but-set-variable warnings.
478    
479    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
480        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
481        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
482        also returns the mark "x". This bug applied to capturing parentheses,
483        non-capturing parentheses, and atomic parentheses. It also applied to some
484        assertions.
485    
486    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
487        information out of configure.ac instead of relying on pcre.h.generic, which
488        is not stored in the repository.
489    
490    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
491        -lreadline.
492    
493    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
494    
495    15. Applied Graycode's patch to put the top-level frame on the stack rather
496        than the heap when not using the stack for recursion. This gives a
497        performance improvement in many cases when recursion is not deep.
498    
499    16. Experimental code added to "pcretest -C" to output the stack frame size.
500    
501    
502    Version 8.21 12-Dec-2011
503    ------------------------
504    
505    1.  Updating the JIT compiler.
506    
507    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
508        are added as well.
509    
510    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
511        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
512        calling _pcre_jit_exec. Some extra comments are added.
513    
514    4.  (*MARK) settings inside atomic groups that do not contain any capturing
515        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
516        was introduced by change 18 for 8.20.
517    
518    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
519        ECMA-262 standard.
520    
521    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
522        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
523        This bug was probably introduced by change 9 of 8.13.
524    
525    7.  While fixing 6 above, I noticed that a number of other items were being
526        incorrectly rejected as "not fixed length". This arose partly because newer
527        opcodes had not been added to the fixed-length checking code. I have (a)
528        corrected the bug and added tests for these items, and (b) arranged for an
529        error to occur if an unknown opcode is encountered while checking for fixed
530        length instead of just assuming "not fixed length". The items that were
531        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
532        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
533        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
534    
535    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
536        being incorrectly compiled and would have given unpredicatble results.
537    
538    9.  A possessively repeated subpattern with minimum repeat count greater than
539        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
540        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
541        the first (A) could occur when it should not.
542    
543    10. Add a cast and remove a redundant test from the code.
544    
545    11. JIT should use pcre_malloc/pcre_free for allocation.
546    
547    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
548        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
549        is anything other than /usr, -L is still shown).
550    
551    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
552    
553    14. Perl does not support \N without a following name in a [] class; PCRE now
554        also gives an error.
555    
556    15. If a forward reference was repeated with an upper limit of around 2000,
557        it caused the error "internal error: overran compiling workspace". The
558        maximum number of forward references (including repeats) was limited by the
559        internal workspace, and dependent on the LINK_SIZE. The code has been
560        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
561        the default depends on LINK_SIZE. There is a new upper limit (for safety)
562        of around 200,000 forward references. While doing this, I also speeded up
563        the filling in of repeated forward references.
564    
565    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
566        incorrectly expecting the subject to contain another "a" after the start.
567    
568    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
569        in the match, the SKIP should be ignored. This was not happening; instead
570        the SKIP was being treated as NOMATCH. For patterns such as
571        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
572        tested.
573    
574    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
575        now much more compatible with Perl, in particular in cases where the result
576        is a non-match for a non-anchored pattern. For example, if
577        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
578        "m", where previously it did not return a name. A side effect of this
579        change is that for partial matches, the last encountered mark name is
580        returned, as for non matches. A number of tests that were previously not
581        Perl-compatible have been moved into the Perl-compatible test files. The
582        refactoring has had the pleasing side effect of removing one argument from
583        the match() function, thus reducing its stack requirements.
584    
585    19. If the /S+ option was used in pcretest to study a pattern using JIT,
586        subsequent uses of /S (without +) incorrectly behaved like /S+.
587    
588    21. Retrieve executable code size support for the JIT compiler and fixing
589        some warnings.
590    
591    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
592        not work when the shorter character appeared right at the end of the
593        subject string.
594    
595    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
596        systems.
597    
598    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
599        output it when the /M option is used in pcretest.
600    
601    25. The CheckMan script was not being included in the distribution. Also, added
602        an explicit "perl" to run Perl scripts from the PrepareRelease script
603        because this is reportedly needed in Windows.
604    
605    26. If study data was being save in a file and studying had not found a set of
606        "starts with" bytes for the pattern, the data written to the file (though
607        never used) was taken from uninitialized memory and so caused valgrind to
608        complain.
609    
610    27. Updated RunTest.bat as provided by Sheri Pierce.
611    
612    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
613    
614    29. Computation of memory usage for the table of capturing group names was
615        giving an unnecessarily large value.
616    
617    
618    Version 8.20 21-Oct-2011
619    ------------------------
620    
621    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
622        a POSIX class. After further experiments with Perl, which convinced me that
623        Perl has bugs and confusions, a closing square bracket is no longer allowed
624        in a POSIX name. This bug also affected patterns with classes that started
625        with full stops.
626    
627    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
628        captured substring, but while checking the failing first alternative,
629        substring 1 is temporarily captured. If the output vector supplied to
630        pcre_exec() was not big enough for this capture, the yield of the function
631        was still zero ("insufficient space for captured substrings"). This cannot
632        be totally fixed without adding another stack variable, which seems a lot
633        of expense for a edge case. However, I have improved the situation in cases
634        such as /(a)(b)x|abc/ matched against "abc", where the return code
635        indicates that fewer than the maximum number of slots in the ovector have
636        been set.
637    
638    3.  Related to (2) above: when there are more back references in a pattern than
639        slots in the output vector, pcre_exec() uses temporary memory during
640        matching, and copies in the captures as far as possible afterwards. It was
641        using the entire output vector, but this conflicts with the specification
642        that only 2/3 is used for passing back captured substrings. Now it uses
643        only the first 2/3, for compatibility. This is, of course, another edge
644        case.
645    
646    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
647        main code base, and can be used by building with --enable-jit. When this is
648        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
649        runtime --no-jit option is given.
650    
651    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
652        ovector, the return from the function was zero, implying that there were
653        other matches that did not fit. The correct "exactly full" value is now
654        returned.
655    
656    6.  If a subpattern that was called recursively or as a subroutine contained
657        (*PRUNE) or any other control that caused it to give a non-standard return,
658        invalid errors such as "Error -26 (nested recursion at the same subject
659        position)" or even infinite loops could occur.
660    
661    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
662        computing the minimum length on reaching *ACCEPT, and so ended up with the
663        wrong value of 1 rather than 0. Further investigation indicates that
664        computing a minimum subject length in the presence of *ACCEPT is difficult
665        (think back references, subroutine calls), and so I have changed the code
666        so that no minimum is registered for a pattern that contains *ACCEPT.
667    
668    8.  If (*THEN) was present in the first (true) branch of a conditional group,
669        it was not handled as intended. [But see 16 below.]
670    
671    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
672        Sheri Pierce.
673    
674    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
675        the first byte in a match must be "a".
676    
677    11. Change 17 for 8.13 increased the recursion depth for patterns like
678        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
679        pattern contains any instances of (*THEN). If it does not, the old
680        optimizations are restored. It would be nice to do this on a per-group
681        basis, but at the moment that is not feasible.
682    
683    12. In some environments, the output of pcretest -C is CRLF terminated. This
684        broke RunTest's code that checks for the link size. A single white space
685        character after the value is now allowed for.
686    
687    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
688        For "fr", it uses the Windows-specific input and output files.
689    
690    14. If (*THEN) appeared in a group that was called recursively or as a
691        subroutine, it did not work as intended. [But see next item.]
692    
693    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
694        pattern fragments (but not containing any | characters). If A and B are
695        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
696        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
697        D. In other words, Perl considers parentheses that do not contain any |
698        characters to be part of a surrounding alternative, whereas PCRE was
699        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
700        differently. PCRE now behaves in the same way as Perl, except in the case
701        of subroutine/recursion calls such as (?1) which have in any case always
702        been different (but PCRE had them first :-).
703    
704    16. Related to 15 above: Perl does not treat the | in a conditional group as
705        creating alternatives. Such a group is treated in the same way as an
706        ordinary group without any | characters when processing (*THEN). PCRE has
707        been changed to match Perl's behaviour.
708    
709    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
710        RunGrepTest script failed.
711    
712    18. Change 22 for version 13 caused atomic groups to use more stack. This is
713        inevitable for groups that contain captures, but it can lead to a lot of
714        stack use in large patterns. The old behaviour has been restored for atomic
715        groups that do not contain any capturing parentheses.
716    
717    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
718        suppress the check for a minimum subject length at run time. (If it was
719        given to pcre_exec() or pcre_dfa_exec() it did work.)
720    
721    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
722        fail to work when decoding hex characters in data strings in EBCDIC
723        environments.
724    
725    21. It appears that in at least one Mac OS environment, the isxdigit() function
726        is implemented as a macro that evaluates to its argument more than once,
727        contravening the C 90 Standard (I haven't checked a later standard). There
728        was an instance in pcretest which caused it to go wrong when processing
729        \x{...} escapes in subject strings. The has been rewritten to avoid using
730        things like p++ in the argument of isxdigit().
731    
732    
733    Version 8.13 16-Aug-2011
734    ------------------------
735    
736    1.  The Unicode data tables have been updated to Unicode 6.0.0.
737    
738    2.  Two minor typos in pcre_internal.h have been fixed.
739    
740    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
741        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
742        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
743    
744    4.  There were a number of related bugs in the code for matching backrefences
745        caselessly in UTF-8 mode when codes for the characters concerned were
746        different numbers of bytes. For example, U+023A and U+2C65 are an upper
747        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
748        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
749        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
750        2-byte code at the end of the subject (it thought there wasn't enough data
751        left).
752    
753    5.  Comprehensive information about what went wrong is now returned by
754        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
755        as the output vector has at least 2 elements. The offset of the start of
756        the failing character and a reason code are placed in the vector.
757    
758    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
759        now returned is for the first byte of the failing character, instead of the
760        last byte inspected. This is an incompatible change, but I hope it is small
761        enough not to be a problem. It makes the returned offset consistent with
762        pcre_exec() and pcre_dfa_exec().
763    
764    7.  pcretest now gives a text phrase as well as the error number when
765        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
766        failure, the offset and reason code are output.
767    
768    8.  When \R was used with a maximizing quantifier it failed to skip backwards
769        over a \r\n pair if the subsequent match failed. Instead, it just skipped
770        back over a single character (\n). This seems wrong (because it treated the
771        two characters as a single entity when going forwards), conflicts with the
772        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
773        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
774        has been changed.
775    
776    9.  Some internal refactoring has changed the processing so that the handling
777        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
778        time (the PCRE_DOTALL option was changed this way some time ago: version
779        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
780        which was always a bit of a fudge. It also means that there is one less
781        argument for the match() function, which reduces its stack requirements
782        slightly. This change also fixes an incompatibility with Perl: the pattern
783        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
784    
785    10. More internal refactoring has drastically reduced the number of recursive
786        calls to match() for possessively repeated groups such as (abc)++ when
787        using pcre_exec().
788    
789    11. While implementing 10, a number of bugs in the handling of groups were
790        discovered and fixed:
791    
792        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
793        (a|)*(?1) gave a compile-time internal error.
794        ((a|)+)+  did not notice that the outer group could match an empty string.
795        (^a|^)+   was not marked as anchored.
796        (.*a|.*)+ was not marked as matching at start or after a newline.
797    
798    12. Yet more internal refactoring has removed another argument from the match()
799        function. Special calls to this function are now indicated by setting a
800        value in a variable in the "match data" data block.
801    
802    13. Be more explicit in pcre_study() instead of relying on "default" for
803        opcodes that mean there is no starting character; this means that when new
804        ones are added and accidentally left out of pcre_study(), testing should
805        pick them up.
806    
807    14. The -s option of pcretest has been documented for ages as being an old
808        synonym of -m (show memory usage). I have changed it to mean "force study
809        for every regex", that is, assume /S for every regex. This is similar to -i
810        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
811        using it. It makes it easier to run collections of tests with and without
812        study enabled, and thereby test pcre_study() more easily. All the standard
813        tests are now run with and without -s (but some patterns can be marked as
814        "never study" - see 20 below).
815    
816    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
817        restoration of the capturing data to the outer values was not happening
818        correctly.
819    
820    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
821        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
822        pattern had matched an empty string, and so incorrectly returned a no
823        match.
824    
825    17. There was optimizing code for the last branch of non-capturing parentheses,
826        and also for the obeyed branch of a conditional subexpression, which used
827        tail recursion to cut down on stack usage. Unfortunately, now that there is
828        the possibility of (*THEN) occurring in these branches, tail recursion is
829        no longer possible because the return has to be checked for (*THEN). These
830        two optimizations have therefore been removed. [But see 8.20/11 above.]
831    
832    18. If a pattern containing \R was studied, it was assumed that \R always
833        matched two bytes, thus causing the minimum subject length to be
834        incorrectly computed because \R can also match just one byte.
835    
836    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
837        was incorrectly computed.
838    
839    20. If /S is present twice on a test pattern in pcretest input, it now
840        *disables* studying, thereby overriding the use of -s on the command line
841        (see 14 above). This is necessary for one or two tests to keep the output
842        identical in both cases.
843    
844    21. When (*ACCEPT) was used in an assertion that matched an empty string and
845        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
846    
847    22. When an atomic group that contained a capturing parenthesis was
848        successfully matched, but the branch in which it appeared failed, the
849        capturing was not being forgotten if a higher numbered group was later
850        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
851        group 1 to "a", when in fact it should be unset. This applied to multi-
852        branched capturing and non-capturing groups, repeated or not, and also to
853        positive assertions (capturing in negative assertions does not happen
854        in PCRE) and also to nested atomic groups.
855    
856    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
857        subject after a captured substring, to make it easier to tell which of a
858        number of identical substrings has been captured.
859    
860    24. The way atomic groups are processed by pcre_exec() has been changed so that
861        if they are repeated, backtracking one repetition now resets captured
862        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
863        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
864        "aaa". Previously, it would have been "a". As part of this code
865        refactoring, the way recursive calls are handled has also been changed.
866    
867    25. If an assertion condition captured any substrings, they were not passed
868        back unless some other capturing happened later. For example, if
869        (?(?=(a))a) was matched against "a", no capturing was returned.
870    
871    26. When studying a pattern that contained subroutine calls or assertions,
872        the code for finding the minimum length of a possible match was handling
873        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
874        group 1 called group 2 while simultaneously a separate group 2 called group
875        1). A stack overflow occurred in this case. I have fixed this by limiting
876        the recursion depth to 10.
877    
878    27. Updated RunTest.bat in the distribution to the version supplied by Tom
879        Fortmann. This supports explicit test numbers on the command line, and has
880        argument validation and error reporting.
881    
882    28. An instance of \X with an unlimited repeat could fail if at any point the
883        first character it looked at was a mark character.
884    
885    29. Some minor code refactoring concerning Unicode properties and scripts
886        should reduce the stack requirement of match() slightly.
887    
888    30. Added the '=' option to pcretest to check the setting of unused capturing
889        slots at the end of the pattern, which are documented as being -1, but are
890        not included in the return count.
891    
892    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
893        compiled something random. Now it gives a compile-time error (as does
894        Perl).
895    
896    32. A *MARK encountered during the processing of a positive assertion is now
897        recorded and passed back (compatible with Perl).
898    
899    33. If --only-matching or --colour was set on a pcregrep call whose pattern
900        had alternative anchored branches, the search for a second match in a line
901        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
902        matched the line "0102" twice. The same bug affected patterns that started
903        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
904        twice.
905    
906    34. Previously, PCRE did not allow quantification of assertions. However, Perl
907        does, and because of capturing effects, quantifying parenthesized
908        assertions may at times be useful. Quantifiers are now allowed for
909        parenthesized assertions.
910    
911    35. A minor code tidy in pcre_compile() when checking options for \R usage.
912    
913    36. \g was being checked for fancy things in a character class, when it should
914        just be a literal "g".
915    
916    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
917        appearance of a nested POSIX class supersedes an apparent external class.
918        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
919        unescaped square brackets may also appear as part of class names. For
920        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
921        more like Perl. (But see 8.20/1 above.)
922    
923    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
924        was because it thought it was \N{name}, which is not supported).
925    
926    39. Add minix to OS list not supporting the -S option in pcretest.
927    
928    40. PCRE tries to detect cases of infinite recursion at compile time, but it
929        cannot analyze patterns in sufficient detail to catch mutual recursions
930        such as ((?1))((?2)). There is now a runtime test that gives an error if a
931        subgroup is called recursively as a subpattern for a second time at the
932        same position in the subject string. In previous releases this might have
933        been caught by the recursion limit, or it might have run out of stack.
934    
935    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
936        happen only once. PCRE was, however incorrectly giving a compile time error
937        "recursive call could loop indefinitely" because it cannot analyze the
938        pattern in sufficient detail. The compile time test no longer happens when
939        PCRE is compiling a conditional subpattern, but actual runaway loops are
940        now caught at runtime (see 40 above).
941    
942    42. It seems that Perl allows any characters other than a closing parenthesis
943        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
944        has been changed to be the same.
945    
946    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
947        as not to get warnings when autogen.sh is called. Also changed
948        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
949    
950    44. To help people who use pcregrep to scan files containing exceedingly long
951        lines, the following changes have been made:
952    
953        (a) The default value of the buffer size parameter has been increased from
954            8K to 20K. (The actual buffer used is three times this size.)
955    
956        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
957            PCRE is built.
958    
959        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
960            to be set at run time.
961    
962        (d) Numerical values in pcregrep options can be followed by K or M, for
963            example --buffer-size=50K.
964    
965        (e) If a line being scanned overflows pcregrep's buffer, an error is now
966            given and the return code is set to 2.
967    
968    45. Add a pointer to the latest mark to the callout data block.
969    
970    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
971        partial match of an empty string instead of no match. This was specific to
972        the use of ".".
973    
974    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
975        complete match instead of a partial match. This bug was dependent on both
976        the PCRE_UTF8 and PCRE_DOTALL options being set.
977    
978    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
979        starting byte set, because \b was not being ignored.
980    
981    
982    Version 8.12 15-Jan-2011
983    ------------------------
984    
985    1.  Fixed some typos in the markup of the man pages, and wrote a script that
986        checks for such things as part of the documentation building process.
987    
988    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
989        --match-limit and --recursion-limit options (added for 8.11). In
990        particular, this made one of the standard tests fail. (The integer value
991        went into the wrong half of a long int.)
992    
993    3.  If the --colour option was given to pcregrep with -v (invert match), it
994        did strange things, either producing crazy output, or crashing. It should,
995        of course, ignore a request for colour when reporting lines that do not
996        match.
997    
998    4.  Another pcregrep bug caused similar problems if --colour was specified with
999        -M (multiline) and the pattern match finished with a line ending.
1000    
1001    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1002        matched in multiline mode, the following line was shown as part of the
1003        match. This seems wrong, so I have changed it.
1004    
1005    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1006        the check for further matches in the same line (so they could be coloured)
1007        to overrun the end of the current line. If another match was found, it was
1008        incorrectly shown (and then shown again when found in the next line).
1009    
1010    7.  If pcregrep was compiled under Windows, there was a reference to the
1011        function pcregrep_exit() before it was defined. I am assuming this was
1012        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1013        reported by a user. I've moved the definition above the reference.
1014    
1015    
1016    Version 8.11 10-Dec-2010
1017    ------------------------
1018    
1019    1.  (*THEN) was not working properly if there were untried alternatives prior
1020        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1021        backtracked to try for "b" instead of moving to the next alternative branch
1022        at the same level (in this case, to look for "c"). The Perl documentation
1023        is clear that when (*THEN) is backtracked onto, it goes to the "next
1024        alternative in the innermost enclosing group".
1025    
1026    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1027        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1028        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1029        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1030        (*THEN).
1031    
1032    3.  If \s appeared in a character class, it removed the VT character from
1033        the class, even if it had been included by some previous item, for example
1034        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1035        of \s, but is part of the POSIX "space" class.)
1036    
1037    4.  A partial match never returns an empty string (because you can always
1038        match an empty string at the end of the subject); however the checking for
1039        an empty string was starting at the "start of match" point. This has been
1040        changed to the "earliest inspected character" point, because the returned
1041        data for a partial match starts at this character. This means that, for
1042        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1043        (previously it gave "no match").
1044    
1045    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1046        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1047        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1048        has an implication that the given string is incomplete (because a partial
1049        match is preferred over a full match). For this reason, these items now
1050        give a partial match in this situation. [Aside: previously, the one case
1051        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1052        match rather than a full match, which was wrong by the old rules, but is
1053        now correct.]
1054    
1055    6.  There was a bug in the handling of #-introduced comments, recognized when
1056        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1057        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1058        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1059        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1060        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1061        places in pcre_compile().
1062    
1063    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1064        comments when looking ahead for named forward references to subpatterns,
1065        the only newline sequence it recognized was NL. It now handles newlines
1066        according to the set newline convention.
1067    
1068    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1069        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1070        cater for a lack of strerror(). These oversights have been fixed.
1071    
1072    9.  Added --match-limit and --recursion-limit to pcregrep.
1073    
1074    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1075    
1076    11. When the -o option was used, pcregrep was setting a return code of 1, even
1077        when matches were found, and --line-buffered was not being honoured.
1078    
1079    12. Added an optional parentheses number to the -o and --only-matching options
1080        of pcregrep.
1081    
1082    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1083        can match an empty string. The code to do it in pcretest and pcredemo
1084        needed fixing:
1085    
1086        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1087            only one byte after an empty string match just before CRLF (this case
1088            just got forgotten; "any" and "anycrlf" were OK).
1089    
1090        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1091            mode when an empty string match preceded an ASCII character followed by
1092            a non-ASCII character. (The code for advancing by one character rather
1093            than one byte was nonsense.)
1094    
1095        (c) The pcredemo.c sample program did not have any code at all to handle
1096            the cases when CRLF is a valid newline sequence.
1097    
1098    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1099        as a starting offset was within the subject string. There is now a new
1100        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1101        negative or greater than the length of the string. In order to test this,
1102        pcretest is extended to allow the setting of negative starting offsets.
1103    
1104    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1105        starting offset points to the beginning of a UTF-8 character was
1106        unnecessarily clumsy. I tidied it up.
1107    
1108    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1109        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1110    
1111    17. Nobody had reported that the --include_dir option, which was added in
1112        release 7.7 should have been called --include-dir (hyphen, not underscore)
1113        for compatibility with GNU grep. I have changed it to --include-dir, but
1114        left --include_dir as an undocumented synonym, and the same for
1115        --exclude-dir, though that is not available in GNU grep, at least as of
1116        release 2.5.4.
1117    
1118    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1119        characters from a string of bytes) have been redefined so as not to use
1120        loops, in order to improve performance in some environments. At the same
1121        time, I abstracted some of the common code into auxiliary macros to save
1122        repetition (this should not affect the compiled code).
1123    
1124    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1125        compile-time error is now given if \c is not followed by an ASCII
1126        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1127        different, and any byte value is allowed.)
1128    
1129    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1130        START_OPTIMIZE option, which is now allowed at compile time - but just
1131        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1132        to pcregrep and other applications that have no direct access to PCRE
1133        options. The new /Y option in pcretest sets this option when calling
1134        pcre_compile().
1135    
1136    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1137        back references. Groups containing recursive back references were forced to
1138        be atomic by that change, but in the case of named groups, the amount of
1139        memory required was incorrectly computed, leading to "Failed: internal
1140        error: code overflow". This has been fixed.
1141    
1142    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1143        pcretest.c, to avoid build problems in some Borland environments.
1144    
1145    
1146    Version 8.10 25-Jun-2010
1147    ------------------------
1148    
1149    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1150        THEN.
1151    
1152    2.  (*ACCEPT) was not working when inside an atomic group.
1153    
1154    3.  Inside a character class, \B is treated as a literal by default, but
1155        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1156        causes the error). The code is unchanged, but I tidied the documentation.
1157    
1158    4.  Inside a character class, PCRE always treated \R and \X as literals,
1159        whereas Perl faults them if its -w option is set. I have changed PCRE so
1160        that it faults them when PCRE_EXTRA is set.
1161    
1162    5.  Added support for \N, which always matches any character other than
1163        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1164    
1165    6.  When compiling pcregrep with newer versions of gcc which may have
1166        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1167        declared with attribute warn_unused_result" were given. Just casting the
1168        result to (void) does not stop the warnings; a more elaborate fudge is
1169        needed. I've used a macro to implement this.
1170    
1171    7.  Minor change to pcretest.c to avoid a compiler warning.
1172    
1173    8.  Added four artifical Unicode properties to help with an option to make
1174        \s etc use properties (see next item). The new properties are: Xan
1175        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1176    
1177    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1178        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1179        this option. Modified pcretest to add /W to test this facility. Added
1180        REG_UCP to make it available via the POSIX interface.
1181    
1182    10. Added --line-buffered to pcregrep.
1183    
1184    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1185        studied, and the match started with a letter with a code point greater than
1186        127 whose first byte was different to the first byte of the other case of
1187        the letter, the other case of this starting letter was not recognized
1188        (#976).
1189    
1190    12. If a pattern that was studied started with a repeated Unicode property
1191        test, for example, \p{Nd}+, there was the theoretical possibility of
1192        setting up an incorrect bitmap of starting bytes, but fortunately it could
1193        not have actually happened in practice until change 8 above was made (it
1194        added property types that matched character-matching opcodes).
1195    
1196    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1197        possible starting bytes for non-anchored patterns.
1198    
1199    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1200        \R, and also a number of cases that involve Unicode properties, both
1201        explicit and implicit when PCRE_UCP is set.
1202    
1203    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1204        input, it could crash or give wrong results if characters with values
1205        greater than 0xc0 were present in the subject string. (Detail: it assumed
1206        UTF-8 input when processing these items.)
1207    
1208    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1209        size_t is 64-bit (#991).
1210    
1211    17. Added a check for running out of memory when PCRE is compiled with
1212        --disable-stack-for-recursion (#990).
1213    
1214    18. If the last data line in a file for pcretest does not have a newline on
1215        the end, a newline was missing in the output.
1216    
1217    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1218        less than 128) in its various bitmaps. However, there is a facility for
1219        generating tables according to the current locale when PCRE is compiled. It
1220        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1221        characters, are recognized by isspace() and therefore were getting set in
1222        these tables, and indeed these tables seem to approximate to ISO 8859. This
1223        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1224        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1225        which of course cannot start UTF-8 characters. I have changed the code so
1226        that only real ASCII characters (less than 128) and the correct starting
1227        bytes for UTF-8 encodings are set for characters greater than 127 when in
1228        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1229        altogether.)
1230    
1231    20. Added the /T option to pcretest so as to be able to run tests with non-
1232        standard character tables, thus making it possible to include the tests
1233        used for 19 above in the standard set of tests.
1234    
1235    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1236        reference to a subpattern the other side of a comment that contains an
1237        opening parenthesis caused either an internal compiling error, or a
1238        reference to the wrong subpattern.
1239    
1240    
1241    Version 8.02 19-Mar-2010
1242    ------------------------
1243    
1244    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1245    
1246    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1247        configured.
1248    
1249    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1250        original author of that file, following a query about its status.
1251    
1252    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1253        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1254    
1255    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1256        quantifier applied to a forward-referencing subroutine call, could compile
1257        incorrect code or give the error "internal error: previously-checked
1258        referenced subpattern not found".
1259    
1260    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1261        variables to point to external functions. For these systems, therefore,
1262        pcre_malloc etc. are now initialized to local functions that call the
1263        relevant global functions.
1264    
1265    7.  There were two entries missing in the vectors called coptable and poptable
1266        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1267        I've fixed the data, and added a kludgy way of testing at compile time that
1268        the lengths are correct (equal to the number of opcodes).
1269    
1270    8.  Following on from 7, I added a similar kludge to check the length of the
1271        eint vector in pcreposix.c.
1272    
1273    9.  Error texts for pcre_compile() are held as one long string to avoid too
1274        much relocation at load time. To find a text, the string is searched,
1275        counting zeros. There was no check for running off the end of the string,
1276        which could happen if a new error number was added without updating the
1277        string.
1278    
1279    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1280    
1281    11. \K was not working if it appeared in an atomic group or in a group that
1282        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1283        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1284        the assertion is positive, but not if it is negative.
1285    
1286    12. Change 11 fortuitously reduced the size of the stack frame used in the
1287        "match()" function of pcre_exec.c by one pointer. Forthcoming
1288        implementation of support for (*MARK) will need an extra pointer on the
1289        stack; I have reserved it now, so that the stack frame size does not
1290        decrease.
1291    
1292    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1293        item in branch that calls a recursion is a subroutine call - as in the
1294        second branch in the above example - was incorrectly given the compile-
1295        time error "recursive call could loop indefinitely" because pcre_compile()
1296        was not correctly checking the subroutine for matching a non-empty string.
1297    
1298    14. The checks for overrunning compiling workspace could trigger after an
1299        overrun had occurred. This is a "should never occur" error, but it can be
1300        triggered by pathological patterns such as hundreds of nested parentheses.
1301        The checks now trigger 100 bytes before the end of the workspace.
1302    
1303    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1304    
1305    
1306    Version 8.01 19-Jan-2010
1307    ------------------------
1308    
1309    1.  If a pattern contained a conditional subpattern with only one branch (in
1310        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1311        computed the wrong minimum data length (which is of course zero for such
1312        subpatterns). This could cause incorrect "no match" results.
1313    
1314    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1315        the pattern is reset in the first branch, pcre_compile() failed with
1316        "internal error: code overflow at offset...". This happened only when
1317        the reset was to the original external option setting. (An optimization
1318        abstracts leading options settings into an external setting, which was the
1319        cause of this.)
1320    
1321    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1322        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1323        assertion pattern did not match (meaning that the assertion was true), it
1324        was incorrectly treated as false if the SKIP had been reached during the
1325        matching. This also applied to assertions used as conditions.
1326    
1327    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1328        assertion subpattern, including such a pattern used as a condition,
1329        unpredictable results occurred, instead of the error return
1330        PCRE_ERROR_DFA_UITEM.
1331    
1332    5.  The C++ GlobalReplace function was not working like Perl for the special
1333        situation when an empty string is matched. It now does the fancy magic
1334        stuff that is necessary.
1335    
1336    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1337        removed. (These were left over from very, very early versions of PCRE.)
1338    
1339    7.  Some cosmetic changes to the code to make life easier when compiling it
1340        as part of something else:
1341    
1342        (a) Change DEBUG to PCRE_DEBUG.
1343    
1344        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1345            called "current" as "current_branch", to prevent a collision with the
1346            Linux macro when compiled as a kernel module.
1347    
1348        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1349            prevent a collision with the Linux macro when compiled as a kernel
1350            module.
1351    
1352    8.  In pcre_compile() there are some checks for integer overflows that used to
1353        cast potentially large values to (double). This has been changed to that
1354        when building, a check for int64_t is made, and if it is found, it is used
1355        instead, thus avoiding the use of floating point arithmetic. (There is no
1356        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1357        double.
1358    
1359    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1360        2005 (difference between two addresses compared to an unsigned value).
1361    
1362    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1363        custom one, because of the following reported problem in Windows:
1364    
1365          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1366              under Win32.
1367          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1368              therefore missing the function definition.
1369          - The compiler thus generates a "C" signature for the test function.
1370          - The linker fails to find the "C" function.
1371          - PCRE fails to configure if asked to do so against libbz2.
1372    
1373    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1374        messages were output:
1375    
1376          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1377          rerunning libtoolize, to keep the correct libtool macros in-tree.
1378          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1379    
1380        I have done both of these things.
1381    
1382    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1383        most of the time, it *can* run out if it is given a pattern that contains a
1384        runaway infinite recursion. I updated the discussion in the pcrestack man
1385        page.
1386    
1387    13. Now that we have gone to the x.xx style of version numbers, the minor
1388        version may start with zero. Using 08 or 09 is a bad idea because users
1389        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1390        interpreted as invalid octal numbers. I've updated the previous comment in
1391        configure.ac, and also added a check that gives an error if 08 or 09 are
1392        used.
1393    
1394    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1395        causing partial matching to fail when the end of the subject matched \W
1396        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1397    
1398    15. There were some discrepancies between the declarations in pcre_internal.h
1399        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1400        their definitions. The declarations used "const uschar *" and the
1401        definitions used USPTR. Even though USPTR is normally defined as "const
1402        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1403        reported that: "This difference in casting confuses some C++ compilers, for
1404        example, SunCC recognizes above declarations as different functions and
1405        generates broken code for hbpcre." I have changed the declarations to use
1406        USPTR.
1407    
1408    16. GNU libtool is named differently on some systems. The autogen.sh script now
1409        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1410        (FreeBSD).
1411    
1412    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1413        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1414        comment: "Figure out how to create a longlong from a string: strtoll and
1415        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1416        instance, but it only takes 2 args instead of 3!"
1417    
1418    18. A subtle bug concerned with back references has been fixed by a change of
1419        specification, with a corresponding code fix. A pattern such as
1420        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1421        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1422        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1423        same bug. Such groups have to be quantified to be useful, or contained
1424        inside another quantified group. (If there's no repetition, the reference
1425        can never match.) The problem arises because, having left the group and
1426        moved on to the rest of the pattern, a later failure that backtracks into
1427        the group uses the captured value from the final iteration of the group
1428        rather than the correct earlier one. I have fixed this in PCRE by forcing
1429        any group that contains a reference to itself to be an atomic group; that
1430        is, there cannot be any backtracking into it once it has completed. This is
1431        similar to recursive and subroutine calls.
1432    
1433    
1434    Version 8.00 19-Oct-09
1435    ----------------------
1436    
1437    1.  The table for translating pcre_compile() error codes into POSIX error codes
1438        was out-of-date, and there was no check on the pcre_compile() error code
1439        being within the table. This could lead to an OK return being given in
1440        error.
1441    
1442    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1443        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1444        in a Windows environment.
1445    
1446    3.  The pcregrep --count option prints the count for each file even when it is
1447        zero, as does GNU grep. However, pcregrep was also printing all files when
1448        --files-with-matches was added. Now, when both options are given, it prints
1449        counts only for those files that have at least one match. (GNU grep just
1450        prints the file name in this circumstance, but including the count seems
1451        more useful - otherwise, why use --count?) Also ensured that the
1452        combination -clh just lists non-zero counts, with no names.
1453    
1454    4.  The long form of the pcregrep -F option was incorrectly implemented as
1455        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1456        but it seems right to fix it, and I didn't think it was worth preserving
1457        the old behaviour.
1458    
1459    5.  The command line items --regex=pattern and --regexp=pattern were not
1460        recognized by pcregrep, which required --regex pattern or --regexp pattern
1461        (with a space rather than an '='). The man page documented the '=' forms,
1462        which are compatible with GNU grep; these now work.
1463    
1464    6.  No libpcreposix.pc file was created for pkg-config; there was just
1465        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1466    
1467    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1468        when UCP support is not needed, by modifying the Python script that
1469        generates it from Unicode data files. This should not matter if the module
1470        is correctly used as a library, but I received one complaint about 50K of
1471        unwanted data. My guess is that the person linked everything into his
1472        program rather than using a library. Anyway, it does no harm.
1473    
1474    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1475        was a minimum greater than 1 for a wide character in a possessive
1476        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1477        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1478        character. Chaos in the form of incorrect output or a compiling loop could
1479        result.
1480    
1481    9.  The restrictions on what a pattern can contain when partial matching is
1482        requested for pcre_exec() have been removed. All patterns can now be
1483        partially matched by this function. In addition, if there are at least two
1484        slots in the offset vector, the offset of the earliest inspected character
1485        for the match and the offset of the end of the subject are set in them when
1486        PCRE_ERROR_PARTIAL is returned.
1487    
1488    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1489        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1490        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1491        and may be more useful for multi-segment matching.
1492    
1493    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1494        used to be given if ever the end of the subject was reached; now it is
1495        given only if matching could not proceed because another character was
1496        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1497        string "Z", which now yields "no match" instead of "partial match". In the
1498        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1499        final character ended with (*FAIL).
1500    
1501    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1502        if the pattern had a "must contain" character that was already found in the
1503        earlier partial match, unless partial matching was again requested. For
1504        example, with the pattern /dog.(body)?/, the "must contain" character is
1505        "g". If the first part-match was for the string "dog", restarting with
1506        "sbody" failed. This bug has been fixed.
1507    
1508    13. The string returned by pcre_dfa_exec() after a partial match has been
1509        changed so that it starts at the first inspected character rather than the
1510        first character of the match. This makes a difference only if the pattern
1511        starts with a lookbehind assertion or \b or \B (\K is not supported by
1512        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1513        matching functions compatible, and I think it's the right thing to do.
1514    
1515    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1516        so that the demonstration program is easily available in environments where
1517        PCRE has not been installed from source.
1518    
1519    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1520        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1521        library.
1522    
1523    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1524        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1525        is not the first non-POSIX option to be added. Clearly some people find
1526        these options useful.
1527    
1528    17. If a caller to the POSIX matching function regexec() passes a non-zero
1529        value for nmatch with a NULL value for pmatch, the value of
1530        nmatch is forced to zero.
1531    
1532    18. RunGrepTest did not have a test for the availability of the -u option of
1533        the diff command, as RunTest does. It now checks in the same way as
1534        RunTest, and also checks for the -b option.
1535    
1536    19. If an odd number of negated classes containing just a single character
1537        interposed, within parentheses, between a forward reference to a named
1538        subpattern and the definition of the subpattern, compilation crashed with
1539        an internal error, complaining that it could not find the referenced
1540        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1541        [The bug was that it was starting one character too far in when skipping
1542        over the character class, thus treating the ] as data rather than
1543        terminating the class. This meant it could skip too much.]
1544    
1545    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1546        /g option in pcretest when the pattern contains \K, which makes it possible
1547        to have an empty string match not at the start, even when the pattern is
1548        anchored. Updated pcretest and pcredemo to use this option.
1549    
1550    21. If the maximum number of capturing subpatterns in a recursion was greater
1551        than the maximum at the outer level, the higher number was returned, but
1552        with unset values at the outer level. The correct (outer level) value is
1553        now given.
1554    
1555    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1556        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1557        make it do so. The string so far is captured, making this feature
1558        compatible with Perl.
1559    
1560    23. The tests have been re-organized, adding tests 11 and 12, to make it
1561        possible to check the Perl 5.10 features against Perl 5.10.
1562    
1563    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1564        pattern matches a fixed length string. PCRE did not allow this; now it
1565        does. Neither allows recursion.
1566    
1567    25. I finally figured out how to implement a request to provide the minimum
1568        length of subject string that was needed in order to match a given pattern.
1569        (It was back references and recursion that I had previously got hung up
1570        on.) This code has now been added to pcre_study(); it finds a lower bound
1571        to the length of subject needed. It is not necessarily the greatest lower
1572        bound, but using it to avoid searching strings that are too short does give
1573        some useful speed-ups. The value is available to calling programs via
1574        pcre_fullinfo().
1575    
1576    26. While implementing 25, I discovered to my embarrassment that pcretest had
1577        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1578        study optimizations had never been tested with that matching function.
1579        Oops. What is worse, even when it was passed study data, there was a bug in
1580        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1581        were also very few tests of studied patterns with pcre_dfa_exec().
1582    
1583    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1584        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1585        on the other side of the coin, they are no longer allowed to have different
1586        names, because these cannot be distinguished in PCRE, and this has caused
1587        confusion. (This is a difference from Perl.)
1588    
1589    28. When duplicate subpattern names are present (necessarily with different
1590        numbers, as required by 27 above), and a test is made by name in a
1591        conditional pattern, either for a subpattern having been matched, or for
1592        recursion in such a pattern, all the associated numbered subpatterns are
1593        tested, and the overall condition is true if the condition is true for any
1594        one of them. This is the way Perl works, and is also more like the way
1595        testing by number works.
1596    
1597    
1598    Version 7.9 11-Apr-09
1599    ---------------------
1600    
1601    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1602        (pcretest), all targets were linked against these libraries. This included
1603        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1604        libraries. This caused unwanted dependencies to be created. This problem
1605        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1606        pcretest is linked with readline.
1607    
1608    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1609        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1610        moved outside it again, because FALSE and TRUE are already defined in AIX,
1611        but BOOL is not.
1612    
1613    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1614        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1615    
1616    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1617        hyphens) following file names and line numbers when outputting matching
1618        lines. This is not true; no spaces are inserted. I have also clarified the
1619        wording for the --colour (or --color) option.
1620    
1621    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1622        was not coloured; this is different to GNU grep, so I have changed it to be
1623        the same.
1624    
1625    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1626        each matching line was coloured. Now it goes on to look for further matches
1627        of any of the test patterns, which is the same behaviour as GNU grep.
1628    
1629    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1630        doesn't make sense to accept an empty string match in pcregrep, so I have
1631        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1632        seems to be how GNU grep behaves.
1633    
1634    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1635        start or after a newline", because the conditional assertion was not being
1636        correctly handled. The rule now is that both the assertion and what follows
1637        in the first alternative must satisfy the test.
1638    
1639    9.  If auto-callout was enabled in a pattern with a conditional group whose
1640        condition was an assertion, PCRE could crash during matching, both with
1641        pcre_exec() and pcre_dfa_exec().
1642    
1643    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1644        used for matching.
1645    
1646    11. Unicode property support in character classes was not working for
1647        characters (bytes) greater than 127 when not in UTF-8 mode.
1648    
1649    12. Added the -M command line option to pcretest.
1650    
1651    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1652    
1653    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1654    
1655    16. Added comments and documentation about mis-use of no_arg in the C++
1656        wrapper.
1657    
1658    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1659        from Martin Jerabek that uses macro names for all relevant character and
1660        string constants.
1661    
1662    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1663        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1664        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1665        these, but not everybody uses configure.
1666    
1667    19. A conditional group that had only one branch was not being correctly
1668        recognized as an item that could match an empty string. This meant that an
1669        enclosing group might also not be so recognized, causing infinite looping
1670        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1671        with the subject "ab", where knowledge that the repeated group can match
1672        nothing is needed in order to break the loop.
1673    
1674    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1675        exec(), but without supplying a callout function, matching went wrong.
1676    
1677    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1678        leak if the size of the offset vector was greater than 30. When the vector
1679        is smaller, the saved offsets during recursion go onto a local stack
1680        vector, but for larger vectors malloc() is used. It was failing to free
1681        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1682        error, in fact).
1683    
1684    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1685        heapframe that is used only when UTF-8 support is enabled. This caused no
1686        problem, but was untidy.
1687    
1688    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1689        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1690        included within another project.
1691    
1692    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1693        slightly modified by me:
1694    
1695          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1696              not building pcregrep.
1697    
1698          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1699              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1700    
1701    25. Forward references, both numeric and by name, in patterns that made use of
1702        duplicate group numbers, could behave incorrectly or give incorrect errors,
1703        because when scanning forward to find the reference group, PCRE was not
1704        taking into account the duplicate group numbers. A pattern such as
1705        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1706    
1707    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1708        the feature of a custom pointer more persuasive (as requested by a user).
1709    
1710    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1711        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1712        pre-defined.
1713    
1714    28. Added support for (*UTF8) at the start of a pattern.
1715    
1716    29. Arrange for flags added by the "release type" setting in CMake to be shown
1717        in the configuration summary.
1718    
1719    
1720    Version 7.8 05-Sep-08
1721    ---------------------
1722    
1723    1.  Replaced UCP searching code with optimized version as implemented for Ad
1724        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1725        stage table and inline lookup instead of a function, giving speed ups of 2
1726        to 5 times on some simple patterns that I tested. Permission was given to
1727        distribute the MultiStage2.py script that generates the tables (it's not in
1728        the tarball, but is in the Subversion repository).
1729    
1730    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1731        scripts.
1732    
1733    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1734        a group with a zero qualifier. The result of the study could be incorrect,
1735        or the function might crash, depending on the pattern.
1736    
1737    4.  Caseless matching was not working for non-ASCII characters in back
1738        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1739        It now works when Unicode Property Support is available.
1740    
1741    5.  In pcretest, an escape such as \x{de} in the data was always generating
1742        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1743        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1744        truncation.
1745    
1746    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1747    
1748    7.  Added two (int) casts to pcregrep when printing the difference of two
1749        pointers, in case they are 64-bit values.
1750    
1751    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1752        test 2 if it fails.
1753    
1754    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1755        and a #define of that name to empty if it is not externally set. This is to
1756        allow users of MSVC to set it if necessary.
1757    
1758    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1759        the convenience functions in the pcre_get.c source file.
1760    
1761    11. An option change at the start of a pattern that had top-level alternatives
1762        could cause overwriting and/or a crash. This command provoked a crash in
1763        some environments:
1764    
1765          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1766    
1767        This potential security problem was recorded as CVE-2008-2371.
1768    
1769    12. For a pattern where the match had to start at the beginning or immediately
1770        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1771        pcre_dfa_exec() could read past the end of the passed subject if there was
1772        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1773        pcretest so that it places the subject at the end of its malloc-ed buffer.
1774    
1775    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1776        exec() might read past the end of the data buffer in UTF-8 mode.
1777    
1778    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1779        the data contained the byte 0x85 as part of a UTF-8 character within its
1780        first line. This applied both to normal and DFA matching.
1781    
1782    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1783        /^[^d]*?$/8 failed to match "abc".
1784    
1785    16. Added a missing copyright notice to pcrecpp_internal.h.
1786    
1787    17. Make it more clear in the documentation that values returned from
1788        pcre_exec() in ovector are byte offsets, not character counts.
1789    
1790    18. Tidied a few places to stop certain compilers from issuing warnings.
1791    
1792    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1793        supplied by Stefan Weber. I made a further small update for 7.8 because
1794        there is a change of source arrangements: the pcre_searchfuncs.c module is
1795        replaced by pcre_ucd.c.
1796    
1797    
1798    Version 7.7 07-May-08
1799    ---------------------
1800    
1801    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1802        a string to a long long, pretend we don't even have a long long." This is
1803        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1804    
1805    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1806        pre-7.6 versions, which defined a global no_arg variable instead of putting
1807        it in the RE class. (See also #8 below.)
1808    
1809    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1810        Lopes.
1811    
1812    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1813    
1814        (1) The include/exclude patterns were being applied to the whole pathnames
1815            of files, instead of just to the final components.
1816    
1817        (2) If there was more than one level of directory, the subdirectories were
1818            skipped unless they satisfied the include/exclude conditions. This is
1819            inconsistent with GNU grep (and could even be seen as contrary to the
1820            pcregrep specification - which I improved to make it absolutely clear).
1821            The action now is always to scan all levels of directory, and just
1822            apply the include/exclude patterns to regular files.
1823    
1824    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1825        --exclude_dir in the tests to avoid scanning .svn directories.
1826    
1827    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1828        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1829        doesn't support NULs in patterns.
1830    
1831    7.  Added some missing "const"s to declarations of static tables in
1832        pcre_compile.c and pcre_dfa_exec.c.
1833    
1834    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1835        caused by fix #2  above. (Subsequently also a second patch to fix the
1836        first patch. And a third patch - this was a messy problem.)
1837    
1838    9.  Applied Craig's patch to remove the use of push_back().
1839    
1840    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1841        matching function regexec().
1842    
1843    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1844        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1845        references. PCRE supports relative numbers with this syntax (I don't think
1846        Oniguruma does).
1847    
1848    12. Previously, a group with a zero repeat such as (...){0} was completely
1849        omitted from the compiled regex. However, this means that if the group
1850        was called as a subroutine from elsewhere in the pattern, things went wrong
1851        (an internal error was given). Such groups are now left in the compiled
1852        pattern, with a new opcode that causes them to be skipped at execution
1853        time.
1854    
1855    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1856        to the way PCRE behaves:
1857    
1858        (a) A lone ] character is dis-allowed (Perl treats it as data).
1859    
1860        (b) A back reference to an unmatched subpattern matches an empty string
1861            (Perl fails the current match path).
1862    
1863        (c) A data ] in a character class must be notated as \] because if the
1864            first data character in a class is ], it defines an empty class. (In
1865            Perl it is not possible to have an empty class.) The empty class []
1866            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1867            The negative empty class [^] matches any one character, independently
1868            of the DOTALL setting.
1869    
1870    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1871        non-existent subpattern following a character class starting with ']' and
1872        containing () gave an internal compiling error instead of "reference to
1873        non-existent subpattern". Fortunately, when the pattern did exist, the
1874        compiled code was correct. (When scanning forwards to check for the
1875        existencd of the subpattern, it was treating the data ']' as terminating
1876        the class, so got the count wrong. When actually compiling, the reference
1877        was subsequently set up correctly.)
1878    
1879    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1880        it was being rejected as not supported by pcre_dfa_exec(), even though
1881        other assertions are supported. I have made pcre_dfa_exec() support
1882        (*FAIL).
1883    
1884    16. The implementation of 13c above involved the invention of a new opcode,
1885        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1886        cannot be changed at match time, I realized I could make a small
1887        improvement to matching performance by compiling OP_ALLANY instead of
1888        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1889        on the OP_ANY path.
1890    
1891    17. Compiling pcretest on Windows with readline support failed without the
1892        following two fixes: (1) Make the unistd.h include conditional on
1893        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1894    
1895    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1896        ncurses library to be included for pcretest when ReadLine support is
1897        requested, but also to allow for it to be overridden. This patch came from
1898        Daniel Bergström.
1899    
1900    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1901        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1902        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1903        spotting this.
1904    
1905    
1906    Version 7.6 28-Jan-08
1907    ---------------------
1908    
1909    1.  A character class containing a very large number of characters with
1910        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1911        overflow.
1912    
1913    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1914        HAVE_LONG_LONG is not defined.
1915    
1916    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1917        bring them up to date and include new features. This patch includes:
1918    
1919        - Fixed PH's badly added libz and libbz2 support.
1920        - Fixed a problem with static linking.
1921        - Added pcredemo. [But later removed - see 7 below.]
1922        - Fixed dftables problem and added an option.
1923        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1924            HAVE_LONG_LONG.
1925        - Added readline support for pcretest.
1926        - Added an listing of the option settings after cmake has run.
1927    
1928    4.  A user submitted a patch to Makefile that makes it easy to create
1929        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1930        Makefile.am that cause it to include this special target, without
1931        affecting anything else. Note that the same mingw target plus all
1932        the other distribution libraries and programs are now supported
1933        when configuring with CMake (see 6 below) instead of with
1934        Configure/Make.
1935    
1936    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1937        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1938        exported in the Windows port". It has not yet been confirmed that the patch
1939        solves the problem, but it does no harm.
1940    
1941    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1942        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1943        with CMake, and also correct the comment about stack recursion.
1944    
1945    7.  Remove the automatic building of pcredemo from the ./configure system and
1946        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1947        of a program that users should build themselves after PCRE is installed, so
1948        building it automatically is not really right. What is more, it gave
1949        trouble in some build environments.
1950    
1951    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1952    
1953    
1954    Version 7.5 10-Jan-08
1955  ---------------------  ---------------------
1956    
1957  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'  1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1958      values in parens when parsing an RE using the C++ wrapper."      values in parens when parsing an RE using the C++ wrapper."
1959    
1960  2.  Negative specials like \S did not work in character classes in UTF-8 mode.  2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1961      Characters greater than 255 were excluded from the class instead of being      Characters greater than 255 were excluded from the class instead of being
1962      included.      included.
1963    
1964  3.  The same bug as (2) above applied to negated POSIX classes such as  3.  The same bug as (2) above applied to negated POSIX classes such as
1965      [:^space:].      [:^space:].
1966    
1967  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it  4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1968      defined or documented. It seems to have been a typo for PCRE_STATIC, so      defined or documented. It seems to have been a typo for PCRE_STATIC, so
1969      I have changed it.      I have changed it.
1970    
1971  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the  5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1972      first named subpattern) and a construct such as (?&a) would reference the      first named subpattern) and a construct such as (?&a) would reference the
1973      first named subpattern whose name started with "a" (in other words, the      first named subpattern whose name started with "a" (in other words, the
1974      length check was missing). Both these problems are fixed. "Subpattern name      length check was missing). Both these problems are fixed. "Subpattern name
1975      expected" is now given for (?&) (a zero-length name), and this patch also      expected" is now given for (?&) (a zero-length name), and this patch also
1976      makes it give the same error for \k'' (previously it complained that that      makes it give the same error for \k'' (previously it complained that that
1977      was a reference to a non-existent subpattern).      was a reference to a non-existent subpattern).
1978    
1979  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;  6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1980      this is right because (?- can be followed by option settings as well as by      this is right because (?- can be followed by option settings as well as by
1981      digits. I have, however, made the messages clearer.      digits. I have, however, made the messages clearer.
1982    
1983  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns  7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1984      than the number used in the conditional) now cause a compile-time error.      than the number used in the conditional) now cause a compile-time error.
1985      This is actually not compatible with Perl, which accepts such patterns, but      This is actually not compatible with Perl, which accepts such patterns, but
1986      treats the conditional as always being FALSE (as PCRE used to), but it      treats the conditional as always being FALSE (as PCRE used to), but it
1987      seems to me that giving a diagnostic is better.      seems to me that giving a diagnostic is better.
1988    
1989  8.  Change "alphameric" to the more common word "alphanumeric" in comments  8.  Change "alphameric" to the more common word "alphanumeric" in comments
1990      and messages.      and messages.
1991    
1992  9.  Fix two occurrences of "backslash" in comments that should have been  9.  Fix two occurrences of "backslash" in comments that should have been
1993      "backspace".      "backspace".
1994    
1995    10. Remove two redundant lines of code that can never be obeyed (their function
1996        was moved elsewhere).
1997    
1998    11. The program that makes PCRE's Unicode character property table had a bug
1999        which caused it to generate incorrect table entries for sequences of
2000        characters that have the same character type, but are in different scripts.
2001        It amalgamated them into a single range, with the script of the first of
2002        them. In other words, some characters were in the wrong script. There were
2003        thirteen such cases, affecting characters in the following ranges:
2004    
2005          U+002b0 - U+002c1
2006          U+0060c - U+0060d
2007          U+0061e - U+00612
2008          U+0064b - U+0065e
2009          U+0074d - U+0076d
2010          U+01800 - U+01805
2011          U+01d00 - U+01d77
2012          U+01d9b - U+01dbf
2013          U+0200b - U+0200f
2014          U+030fc - U+030fe
2015          U+03260 - U+0327f
2016          U+0fb46 - U+0fbb1
2017          U+10450 - U+1049d
2018    
2019    12. The -o option (show only the matching part of a line) for pcregrep was not
2020        compatible with GNU grep in that, if there was more than one match in a
2021        line, it showed only the first of them. It now behaves in the same way as
2022        GNU grep.
2023    
2024    13. If the -o and -v options were combined for pcregrep, it printed a blank
2025        line for every non-matching line. GNU grep prints nothing, and pcregrep now
2026        does the same. The return code can be used to tell if there were any
2027        non-matching lines.
2028    
2029    14. Added --file-offsets and --line-offsets to pcregrep.
2030    
2031    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2032        infinitely looping recursion. The bug was that positive lookaheads were not
2033        being skipped when checking for a possible empty match (negative lookaheads
2034        and both kinds of lookbehind were skipped).
2035    
2036    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2037        inclusion of <windows.h> to before rather than after the definition of
2038        INVALID_FILE_ATTRIBUTES (patch from David Byron).
2039    
2040    17. Specifying a possessive quantifier with a specific limit for a Unicode
2041        character property caused pcre_compile() to compile bad code, which led at
2042        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2043        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2044        caused the error; without that there was no problem.
2045    
2046    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2047    
2048    19. Added --enable-pcretest-libreadline.
2049    
2050    20. In pcrecpp.cc, the variable 'count' was incremented twice in
2051        RE::GlobalReplace(). As a result, the number of replacements returned was
2052        double what it should be. I removed one of the increments, but Craig sent a
2053        later patch that removed the other one (the right fix) and added unit tests
2054        that check the return values (which was not done before).
2055    
2056    21. Several CMake things:
2057    
2058        (1) Arranged that, when cmake is used on Unix, the libraries end up with
2059            the names libpcre and libpcreposix, not just pcre and pcreposix.
2060    
2061        (2) The above change means that pcretest and pcregrep are now correctly
2062            linked with the newly-built libraries, not previously installed ones.
2063    
2064        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2065    
2066    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2067        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2068        UTF-8 newline character). The key issue is that the pattern starts .*;
2069        this means that the match must be either at the beginning, or after a
2070        newline. The bug was in the code for advancing after a failed match and
2071        checking that the new position followed a newline. It was not taking
2072        account of UTF-8 characters correctly.
2073    
2074    23. PCRE was behaving differently from Perl in the way it recognized POSIX
2075        character classes. PCRE was not treating the sequence [:...:] as a
2076        character class unless the ... were all letters. Perl, however, seems to
2077        allow any characters between [: and :], though of course it rejects as
2078        unknown any "names" that contain non-letters, because all the known class
2079        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2080        for example, whereas PCRE did not - it did not recognize a POSIX character
2081        class. This seemed a bit dangerous, so the code has been changed to be
2082        closer to Perl. The behaviour is not identical to Perl, because PCRE will
2083        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2084        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2085        Perl does, and where it didn't before.
2086    
2087    24. Rewrite so as to remove the single use of %n from pcregrep because in some
2088        Windows environments %n is disabled by default.
2089    
2090    
2091  Version 7.4 21-Sep-07  Version 7.4 21-Sep-07

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