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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.0 02 Jul-08  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    
98    Version 8.32 30-November-2012
99    -----------------------------
100    
101    1.  Improved JIT compiler optimizations for first character search and single
102        character iterators.
103    
104    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
105        Patch by Daniel Richard G.
106    
107    3.  Single character iterator optimizations in the JIT compiler.
108    
109    4.  Improved JIT compiler optimizations for character ranges.
110    
111    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
112        Reported by Giuseppe D'Angelo.
113    
114    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
115        of a line, was being set incorrectly in cases where .* appeared inside
116        atomic brackets at the start of a pattern, or where there was a subsequent
117        *PRUNE or *SKIP.
118    
119    7.  Improved instruction cache flush for POWER/PowerPC.
120        Patch by Daniel Richard G.
121    
122    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
123        grep:
124    
125        (a) There is now no limit to the number of patterns to be matched.
126    
127        (b) An error is given if a pattern is too long.
128    
129        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
130            are now supported.
131    
132        (d) --exclude-from and --include-from (multiple use) have been added.
133    
134        (e) Exclusions and inclusions now apply to all files and directories, not
135            just to those obtained from scanning a directory recursively.
136    
137        (f) Multiple uses of -f and --file-list are now supported.
138    
139        (g) In a Windows environment, the default for -d has been changed from
140            "read" (the GNU grep default) to "skip", because otherwise the presence
141            of a directory in the file list provokes an error.
142    
143        (h) The documentation has been revised and clarified in places.
144    
145    9.  Improve the matching speed of capturing brackets.
146    
147    10. Changed the meaning of \X so that it now matches a Unicode extended
148        grapheme cluster.
149    
150    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
151        out POSIX threads when JIT support is configured.
152    
153    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
154    
155    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
156        structure could go wrong in environments where size_t is not the same size
157        as int.
158    
159    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
160        set.
161    
162    15. The EBCDIC support had decayed; later updates to the code had included
163        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
164        general tidy up of EBCDIC-related issues, and the documentation was also
165        not quite right. There is now a test that can be run on ASCII systems to
166        check some of the EBCDIC-related things (but is it not a full test).
167    
168    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
169        in a small tidy to the code.
170    
171    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
172    
173    18. If the --only-matching (-o) option in pcregrep is specified multiple
174        times, each one causes appropriate output. For example, -o1 -o2 outputs the
175        substrings matched by the 1st and 2nd capturing parentheses. A separating
176        string can be specified by --om-separator (default empty).
177    
178    19. Improving the first n character searches.
179    
180    20. Turn case lists for horizontal and vertical white space into macros so that
181        they are defined only once.
182    
183    21. This set of changes together give more compatible Unicode case-folding
184        behaviour for characters that have more than one other case when UCP
185        support is available.
186    
187        (a) The Unicode property table now has offsets into a new table of sets of
188            three or more characters that are case-equivalent. The MultiStage2.py
189            script that generates these tables (the pcre_ucd.c file) now scans
190            CaseFolding.txt instead of UnicodeData.txt for character case
191            information.
192    
193        (b) The code for adding characters or ranges of characters to a character
194            class has been abstracted into a generalized function that also handles
195            case-independence. In UTF-mode with UCP support, this uses the new data
196            to handle characters with more than one other case.
197    
198        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
199            whose other case is greater than 256 are now correctly matched
200            caselessly. Previously, the high codepoint matched the low one, but not
201            vice versa.
202    
203        (d) The processing of \h, \H, \v, and \ in character classes now makes use
204            of the new class addition function, using character lists defined as
205            macros alongside the case definitions of 20 above.
206    
207        (e) Caseless back references now work with characters that have more than
208            one other case.
209    
210        (f) General caseless matching of characters with more than one other case
211            is supported.
212    
213    22. Unicode character properties were updated from Unicode 6.2.0
214    
215    23. Improved CMake support under Windows. Patch by Daniel Richard G.
216    
217    24. Add support for 32-bit character strings, and UTF-32
218    
219    25. Major JIT compiler update (code refactoring and bugfixing).
220        Experimental Sparc 32 support is added.
221    
222    26. Applied a modified version of Daniel Richard G's patch to create
223        pcre.h.generic and config.h.generic by "make" instead of in the
224        PrepareRelease script.
225    
226    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
227        pcre_compile.c when checking for a zero character.
228    
229    28. Introducing a native interface for JIT. Through this interface, the compiled
230        machine code can be directly executed. The purpose of this interface is to
231        provide fast pattern matching, so several sanity checks are not performed.
232        However, feature tests are still performed. The new interface provides
233        1.4x speedup compared to the old one.
234    
235    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
236        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
237        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
238    
239    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
240        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
241        the "old" RFC 2279). Instead, it ended up passing a negative length to
242        pcre_exec().
243    
244    31. Add support for GCC's visibility feature to hide internal functions.
245    
246    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
247        "unknown -C option" after outputting 0 or 1.
248    
249    33. There is now support for generating a code coverage report for the test
250        suite in environments where gcc is the compiler and lcov is installed. This
251        is mainly for the benefit of the developers.
252    
253    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
254        unaddressable using valgrind annotations, allowing valgrind to detect
255        invalid memory accesses. This is mainly for the benefit of the developers.
256    
257    25. (*UTF) can now be used to start a pattern in any of the three libraries.
258    
259    26. Give configure error if --enable-cpp but no C++ compiler found.
260    
261    
262    Version 8.31 06-July-2012
263    -------------------------
264    
265    1.  Fixing a wrong JIT test case and some compiler warnings.
266    
267    2.  Removed a bashism from the RunTest script.
268    
269    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
270        to unsigned type, result still unsigned" that was given by an MS compiler
271        on encountering the code "-sizeof(xxx)".
272    
273    4.  Partial matching support is added to the JIT compiler.
274    
275    5.  Fixed several bugs concerned with partial matching of items that consist
276        of more than one character:
277    
278        (a) /^(..)\1/ did not partially match "aba" because checking references was
279            done on an "all or nothing" basis. This also applied to repeated
280            references.
281    
282        (b) \R did not give a hard partial match if \r was found at the end of the
283            subject.
284    
285        (c) \X did not give a hard partial match after matching one or more
286            characters at the end of the subject.
287    
288        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
289            a partial match for the string "\r".
290    
291        (e) When newline was set to CRLF, the metacharacter "." did not recognize
292            a partial match for a CR character at the end of the subject string.
293    
294    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
295        running pcretest, the text "(JIT)" added to the output whenever JIT is
296        actually used to run the match.
297    
298    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
299        or /S+[+] with a digit between 1 and 7.
300    
301    8.  OP_NOT now supports any UTF character not just single-byte ones.
302    
303    9.  (*MARK) control verb is now supported by the JIT compiler.
304    
305    10. The command "./RunTest list" lists the available tests without actually
306        running any of them. (Because I keep forgetting what they all are.)
307    
308    11. Add PCRE_INFO_MAXLOOKBEHIND.
309    
310    12. Applied a (slightly modified) user-supplied patch that improves performance
311        when the heap is used for recursion (compiled with --disable-stack-for-
312        recursion). Instead of malloc and free for each heap frame each time a
313        logical recursion happens, frames are retained on a chain and re-used where
314        possible. This sometimes gives as much as 30% improvement.
315    
316    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
317        call.
318    
319    14. As documented, (*COMMIT) is now confined to within a positive assertion.
320    
321    15. It is now possible to link pcretest with libedit as an alternative to
322        libreadline.
323    
324    16. (*COMMIT) control verb is now supported by the JIT compiler.
325    
326    17. The Unicode data tables have been updated to Unicode 6.1.0.
327    
328    18. Added --file-list option to pcregrep.
329    
330    19. Added binary file support to pcregrep, including the -a, --binary-files,
331        -I, and --text options.
332    
333    20. The madvise function is renamed for posix_madvise for QNX compatibility
334        reasons. Fixed by Giuseppe D'Angelo.
335    
336    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
337    
338    22. Changed the option for creating symbolic links for 16-bit man pages from
339        -s to -sf so that re-installing does not cause issues.
340    
341    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
342    
343    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
344        matches in certain environments (the workspace was not being correctly
345        retained). Also added to pcre_dfa_exec() a simple plausibility check on
346        some of the workspace data at the beginning of a restart.
347    
348    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
349        was not doing so when it should - probably a typo introduced by SVN 528
350        (change 8.10/14).
351    
352    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
353        \w+ when the character tables indicated that \x{c4} was a word character.
354        There were several related cases, all because the tests for doing a table
355        lookup were testing for characters less than 127 instead of 255.
356    
357    27. If a pattern contains capturing parentheses that are not used in a match,
358        their slots in the ovector are set to -1. For those that are higher than
359        any matched groups, this happens at the end of processing. In the case when
360        there were back references that the ovector was too small to contain
361        (causing temporary malloc'd memory to be used during matching), and the
362        highest capturing number was not used, memory off the end of the ovector
363        was incorrectly being set to -1. (It was using the size of the temporary
364        memory instead of the true size.)
365    
366    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
367        ovector size, it uses memory at the end of the block that it has got.
368    
369    29. Check for an overlong MARK name and give an error at compile time. The
370        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
371    
372    30. JIT compiler update.
373    
374    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
375        Rill for the patch.
376    
377    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
378    
379    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
380    
381    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
382        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
383        was enabled.
384    
385    35. Improve JIT code generation for greedy plus quantifier.
386    
387    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
388        1 to "aa" instead of to an empty string. The bug affected repeated groups
389        that could potentially match an empty string.
390    
391    37. Optimizing single character iterators in JIT.
392    
393    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
394        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
395        codepoints that are too big for the mode are faulted, and in a UTF mode,
396        disallowed codepoints are also faulted.
397    
398    39. If PCRE was compiled with UTF support, in three places in the DFA
399        matcher there was code that should only have been obeyed in UTF mode, but
400        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
401        processing when bytes with values greater than 127 were present. In 16-bit
402        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
403        both cases the values are those that cannot be the first data item in a UTF
404        character. The three items that might have provoked this were recursions,
405        possessively repeated groups, and atomic groups.
406    
407    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
408        and pcregrep, because some OS require shared objects to be explicitly
409        passed to ld, causing the link step to fail if they are not.
410    
411    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
412        mode, patterns that started with \h* or \R* might be incorrectly matched.
413    
414    
415    Version 8.30 04-February-2012
416    -----------------------------
417    
418    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
419        name is defined in ctype.h.
420    
421    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
422        only in quite long subpatterns.
423    
424    3.  Removed the function pcre_info(), which has been obsolete and deprecated
425        since it was replaced by pcre_fullinfo() in February 2000.
426    
427    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
428        match a (*MARK), and the match failed at the start of the subject, a
429        reference to memory before the start of the subject could occur. This bug
430        was introduced by fix 17 of release 8.21.
431    
432    5.  A reference to an unset group with zero minimum repetition was giving
433        totally wrong answers (in non-JavaScript-compatibility mode). For example,
434        /(another)?(\1?)test/ matched against "hello world test". This bug was
435        introduced in release 8.13.
436    
437    6.  Add support for 16-bit character strings (a large amount of work involving
438        many changes and refactorings).
439    
440    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
441        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
442        from a file.
443    
444    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
445        rounding is not applied in this particular case).
446    
447    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
448        if they appear, or are escaped, in patterns.
449    
450    10. Get rid of a number of -Wunused-but-set-variable warnings.
451    
452    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
453        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
454        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
455        also returns the mark "x". This bug applied to capturing parentheses,
456        non-capturing parentheses, and atomic parentheses. It also applied to some
457        assertions.
458    
459    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
460        information out of configure.ac instead of relying on pcre.h.generic, which
461        is not stored in the repository.
462    
463    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
464        -lreadline.
465    
466    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
467    
468    15. Applied Graycode's patch to put the top-level frame on the stack rather
469        than the heap when not using the stack for recursion. This gives a
470        performance improvement in many cases when recursion is not deep.
471    
472    16. Experimental code added to "pcretest -C" to output the stack frame size.
473    
474    
475    Version 8.21 12-Dec-2011
476    ------------------------
477    
478    1.  Updating the JIT compiler.
479    
480    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
481        are added as well.
482    
483    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
484        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
485        calling _pcre_jit_exec. Some extra comments are added.
486    
487    4.  (*MARK) settings inside atomic groups that do not contain any capturing
488        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
489        was introduced by change 18 for 8.20.
490    
491    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
492        ECMA-262 standard.
493    
494    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
495        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
496        This bug was probably introduced by change 9 of 8.13.
497    
498    7.  While fixing 6 above, I noticed that a number of other items were being
499        incorrectly rejected as "not fixed length". This arose partly because newer
500        opcodes had not been added to the fixed-length checking code. I have (a)
501        corrected the bug and added tests for these items, and (b) arranged for an
502        error to occur if an unknown opcode is encountered while checking for fixed
503        length instead of just assuming "not fixed length". The items that were
504        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
505        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
506        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
507    
508    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
509        being incorrectly compiled and would have given unpredicatble results.
510    
511    9.  A possessively repeated subpattern with minimum repeat count greater than
512        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
513        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
514        the first (A) could occur when it should not.
515    
516    10. Add a cast and remove a redundant test from the code.
517    
518    11. JIT should use pcre_malloc/pcre_free for allocation.
519    
520    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
521        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
522        is anything other than /usr, -L is still shown).
523    
524    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
525    
526    14. Perl does not support \N without a following name in a [] class; PCRE now
527        also gives an error.
528    
529    15. If a forward reference was repeated with an upper limit of around 2000,
530        it caused the error "internal error: overran compiling workspace". The
531        maximum number of forward references (including repeats) was limited by the
532        internal workspace, and dependent on the LINK_SIZE. The code has been
533        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
534        the default depends on LINK_SIZE. There is a new upper limit (for safety)
535        of around 200,000 forward references. While doing this, I also speeded up
536        the filling in of repeated forward references.
537    
538    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
539        incorrectly expecting the subject to contain another "a" after the start.
540    
541    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
542        in the match, the SKIP should be ignored. This was not happening; instead
543        the SKIP was being treated as NOMATCH. For patterns such as
544        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
545        tested.
546    
547    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
548        now much more compatible with Perl, in particular in cases where the result
549        is a non-match for a non-anchored pattern. For example, if
550        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
551        "m", where previously it did not return a name. A side effect of this
552        change is that for partial matches, the last encountered mark name is
553        returned, as for non matches. A number of tests that were previously not
554        Perl-compatible have been moved into the Perl-compatible test files. The
555        refactoring has had the pleasing side effect of removing one argument from
556        the match() function, thus reducing its stack requirements.
557    
558    19. If the /S+ option was used in pcretest to study a pattern using JIT,
559        subsequent uses of /S (without +) incorrectly behaved like /S+.
560    
561    21. Retrieve executable code size support for the JIT compiler and fixing
562        some warnings.
563    
564    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
565        not work when the shorter character appeared right at the end of the
566        subject string.
567    
568    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
569        systems.
570    
571    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
572        output it when the /M option is used in pcretest.
573    
574    25. The CheckMan script was not being included in the distribution. Also, added
575        an explicit "perl" to run Perl scripts from the PrepareRelease script
576        because this is reportedly needed in Windows.
577    
578    26. If study data was being save in a file and studying had not found a set of
579        "starts with" bytes for the pattern, the data written to the file (though
580        never used) was taken from uninitialized memory and so caused valgrind to
581        complain.
582    
583    27. Updated RunTest.bat as provided by Sheri Pierce.
584    
585    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
586    
587    29. Computation of memory usage for the table of capturing group names was
588        giving an unnecessarily large value.
589    
590    
591    Version 8.20 21-Oct-2011
592    ------------------------
593    
594    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
595        a POSIX class. After further experiments with Perl, which convinced me that
596        Perl has bugs and confusions, a closing square bracket is no longer allowed
597        in a POSIX name. This bug also affected patterns with classes that started
598        with full stops.
599    
600    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
601        captured substring, but while checking the failing first alternative,
602        substring 1 is temporarily captured. If the output vector supplied to
603        pcre_exec() was not big enough for this capture, the yield of the function
604        was still zero ("insufficient space for captured substrings"). This cannot
605        be totally fixed without adding another stack variable, which seems a lot
606        of expense for a edge case. However, I have improved the situation in cases
607        such as /(a)(b)x|abc/ matched against "abc", where the return code
608        indicates that fewer than the maximum number of slots in the ovector have
609        been set.
610    
611    3.  Related to (2) above: when there are more back references in a pattern than
612        slots in the output vector, pcre_exec() uses temporary memory during
613        matching, and copies in the captures as far as possible afterwards. It was
614        using the entire output vector, but this conflicts with the specification
615        that only 2/3 is used for passing back captured substrings. Now it uses
616        only the first 2/3, for compatibility. This is, of course, another edge
617        case.
618    
619    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
620        main code base, and can be used by building with --enable-jit. When this is
621        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
622        runtime --no-jit option is given.
623    
624    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
625        ovector, the return from the function was zero, implying that there were
626        other matches that did not fit. The correct "exactly full" value is now
627        returned.
628    
629    6.  If a subpattern that was called recursively or as a subroutine contained
630        (*PRUNE) or any other control that caused it to give a non-standard return,
631        invalid errors such as "Error -26 (nested recursion at the same subject
632        position)" or even infinite loops could occur.
633    
634    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
635        computing the minimum length on reaching *ACCEPT, and so ended up with the
636        wrong value of 1 rather than 0. Further investigation indicates that
637        computing a minimum subject length in the presence of *ACCEPT is difficult
638        (think back references, subroutine calls), and so I have changed the code
639        so that no minimum is registered for a pattern that contains *ACCEPT.
640    
641    8.  If (*THEN) was present in the first (true) branch of a conditional group,
642        it was not handled as intended. [But see 16 below.]
643    
644    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
645        Sheri Pierce.
646    
647    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
648        the first byte in a match must be "a".
649    
650    11. Change 17 for 8.13 increased the recursion depth for patterns like
651        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
652        pattern contains any instances of (*THEN). If it does not, the old
653        optimizations are restored. It would be nice to do this on a per-group
654        basis, but at the moment that is not feasible.
655    
656    12. In some environments, the output of pcretest -C is CRLF terminated. This
657        broke RunTest's code that checks for the link size. A single white space
658        character after the value is now allowed for.
659    
660    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
661        For "fr", it uses the Windows-specific input and output files.
662    
663    14. If (*THEN) appeared in a group that was called recursively or as a
664        subroutine, it did not work as intended. [But see next item.]
665    
666    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
667        pattern fragments (but not containing any | characters). If A and B are
668        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
669        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
670        D. In other words, Perl considers parentheses that do not contain any |
671        characters to be part of a surrounding alternative, whereas PCRE was
672        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
673        differently. PCRE now behaves in the same way as Perl, except in the case
674        of subroutine/recursion calls such as (?1) which have in any case always
675        been different (but PCRE had them first :-).
676    
677    16. Related to 15 above: Perl does not treat the | in a conditional group as
678        creating alternatives. Such a group is treated in the same way as an
679        ordinary group without any | characters when processing (*THEN). PCRE has
680        been changed to match Perl's behaviour.
681    
682    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
683        RunGrepTest script failed.
684    
685    18. Change 22 for version 13 caused atomic groups to use more stack. This is
686        inevitable for groups that contain captures, but it can lead to a lot of
687        stack use in large patterns. The old behaviour has been restored for atomic
688        groups that do not contain any capturing parentheses.
689    
690    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
691        suppress the check for a minimum subject length at run time. (If it was
692        given to pcre_exec() or pcre_dfa_exec() it did work.)
693    
694    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
695        fail to work when decoding hex characters in data strings in EBCDIC
696        environments.
697    
698    21. It appears that in at least one Mac OS environment, the isxdigit() function
699        is implemented as a macro that evaluates to its argument more than once,
700        contravening the C 90 Standard (I haven't checked a later standard). There
701        was an instance in pcretest which caused it to go wrong when processing
702        \x{...} escapes in subject strings. The has been rewritten to avoid using
703        things like p++ in the argument of isxdigit().
704    
705    
706    Version 8.13 16-Aug-2011
707    ------------------------
708    
709    1.  The Unicode data tables have been updated to Unicode 6.0.0.
710    
711    2.  Two minor typos in pcre_internal.h have been fixed.
712    
713    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
714        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
715        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
716    
717    4.  There were a number of related bugs in the code for matching backrefences
718        caselessly in UTF-8 mode when codes for the characters concerned were
719        different numbers of bytes. For example, U+023A and U+2C65 are an upper
720        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
721        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
722        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
723        2-byte code at the end of the subject (it thought there wasn't enough data
724        left).
725    
726    5.  Comprehensive information about what went wrong is now returned by
727        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
728        as the output vector has at least 2 elements. The offset of the start of
729        the failing character and a reason code are placed in the vector.
730    
731    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
732        now returned is for the first byte of the failing character, instead of the
733        last byte inspected. This is an incompatible change, but I hope it is small
734        enough not to be a problem. It makes the returned offset consistent with
735        pcre_exec() and pcre_dfa_exec().
736    
737    7.  pcretest now gives a text phrase as well as the error number when
738        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
739        failure, the offset and reason code are output.
740    
741    8.  When \R was used with a maximizing quantifier it failed to skip backwards
742        over a \r\n pair if the subsequent match failed. Instead, it just skipped
743        back over a single character (\n). This seems wrong (because it treated the
744        two characters as a single entity when going forwards), conflicts with the
745        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
746        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
747        has been changed.
748    
749    9.  Some internal refactoring has changed the processing so that the handling
750        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
751        time (the PCRE_DOTALL option was changed this way some time ago: version
752        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
753        which was always a bit of a fudge. It also means that there is one less
754        argument for the match() function, which reduces its stack requirements
755        slightly. This change also fixes an incompatibility with Perl: the pattern
756        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
757    
758    10. More internal refactoring has drastically reduced the number of recursive
759        calls to match() for possessively repeated groups such as (abc)++ when
760        using pcre_exec().
761    
762    11. While implementing 10, a number of bugs in the handling of groups were
763        discovered and fixed:
764    
765        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
766        (a|)*(?1) gave a compile-time internal error.
767        ((a|)+)+  did not notice that the outer group could match an empty string.
768        (^a|^)+   was not marked as anchored.
769        (.*a|.*)+ was not marked as matching at start or after a newline.
770    
771    12. Yet more internal refactoring has removed another argument from the match()
772        function. Special calls to this function are now indicated by setting a
773        value in a variable in the "match data" data block.
774    
775    13. Be more explicit in pcre_study() instead of relying on "default" for
776        opcodes that mean there is no starting character; this means that when new
777        ones are added and accidentally left out of pcre_study(), testing should
778        pick them up.
779    
780    14. The -s option of pcretest has been documented for ages as being an old
781        synonym of -m (show memory usage). I have changed it to mean "force study
782        for every regex", that is, assume /S for every regex. This is similar to -i
783        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
784        using it. It makes it easier to run collections of tests with and without
785        study enabled, and thereby test pcre_study() more easily. All the standard
786        tests are now run with and without -s (but some patterns can be marked as
787        "never study" - see 20 below).
788    
789    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
790        restoration of the capturing data to the outer values was not happening
791        correctly.
792    
793    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
794        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
795        pattern had matched an empty string, and so incorrectly returned a no
796        match.
797    
798    17. There was optimizing code for the last branch of non-capturing parentheses,
799        and also for the obeyed branch of a conditional subexpression, which used
800        tail recursion to cut down on stack usage. Unfortunately, now that there is
801        the possibility of (*THEN) occurring in these branches, tail recursion is
802        no longer possible because the return has to be checked for (*THEN). These
803        two optimizations have therefore been removed. [But see 8.20/11 above.]
804    
805    18. If a pattern containing \R was studied, it was assumed that \R always
806        matched two bytes, thus causing the minimum subject length to be
807        incorrectly computed because \R can also match just one byte.
808    
809    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
810        was incorrectly computed.
811    
812    20. If /S is present twice on a test pattern in pcretest input, it now
813        *disables* studying, thereby overriding the use of -s on the command line
814        (see 14 above). This is necessary for one or two tests to keep the output
815        identical in both cases.
816    
817    21. When (*ACCEPT) was used in an assertion that matched an empty string and
818        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
819    
820    22. When an atomic group that contained a capturing parenthesis was
821        successfully matched, but the branch in which it appeared failed, the
822        capturing was not being forgotten if a higher numbered group was later
823        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
824        group 1 to "a", when in fact it should be unset. This applied to multi-
825        branched capturing and non-capturing groups, repeated or not, and also to
826        positive assertions (capturing in negative assertions does not happen
827        in PCRE) and also to nested atomic groups.
828    
829    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
830        subject after a captured substring, to make it easier to tell which of a
831        number of identical substrings has been captured.
832    
833    24. The way atomic groups are processed by pcre_exec() has been changed so that
834        if they are repeated, backtracking one repetition now resets captured
835        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
836        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
837        "aaa". Previously, it would have been "a". As part of this code
838        refactoring, the way recursive calls are handled has also been changed.
839    
840    25. If an assertion condition captured any substrings, they were not passed
841        back unless some other capturing happened later. For example, if
842        (?(?=(a))a) was matched against "a", no capturing was returned.
843    
844    26. When studying a pattern that contained subroutine calls or assertions,
845        the code for finding the minimum length of a possible match was handling
846        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
847        group 1 called group 2 while simultaneously a separate group 2 called group
848        1). A stack overflow occurred in this case. I have fixed this by limiting
849        the recursion depth to 10.
850    
851    27. Updated RunTest.bat in the distribution to the version supplied by Tom
852        Fortmann. This supports explicit test numbers on the command line, and has
853        argument validation and error reporting.
854    
855    28. An instance of \X with an unlimited repeat could fail if at any point the
856        first character it looked at was a mark character.
857    
858    29. Some minor code refactoring concerning Unicode properties and scripts
859        should reduce the stack requirement of match() slightly.
860    
861    30. Added the '=' option to pcretest to check the setting of unused capturing
862        slots at the end of the pattern, which are documented as being -1, but are
863        not included in the return count.
864    
865    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
866        compiled something random. Now it gives a compile-time error (as does
867        Perl).
868    
869    32. A *MARK encountered during the processing of a positive assertion is now
870        recorded and passed back (compatible with Perl).
871    
872    33. If --only-matching or --colour was set on a pcregrep call whose pattern
873        had alternative anchored branches, the search for a second match in a line
874        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
875        matched the line "0102" twice. The same bug affected patterns that started
876        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
877        twice.
878    
879    34. Previously, PCRE did not allow quantification of assertions. However, Perl
880        does, and because of capturing effects, quantifying parenthesized
881        assertions may at times be useful. Quantifiers are now allowed for
882        parenthesized assertions.
883    
884    35. A minor code tidy in pcre_compile() when checking options for \R usage.
885    
886    36. \g was being checked for fancy things in a character class, when it should
887        just be a literal "g".
888    
889    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
890        appearance of a nested POSIX class supersedes an apparent external class.
891        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
892        unescaped square brackets may also appear as part of class names. For
893        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
894        more like Perl. (But see 8.20/1 above.)
895    
896    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
897        was because it thought it was \N{name}, which is not supported).
898    
899    39. Add minix to OS list not supporting the -S option in pcretest.
900    
901    40. PCRE tries to detect cases of infinite recursion at compile time, but it
902        cannot analyze patterns in sufficient detail to catch mutual recursions
903        such as ((?1))((?2)). There is now a runtime test that gives an error if a
904        subgroup is called recursively as a subpattern for a second time at the
905        same position in the subject string. In previous releases this might have
906        been caught by the recursion limit, or it might have run out of stack.
907    
908    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
909        happen only once. PCRE was, however incorrectly giving a compile time error
910        "recursive call could loop indefinitely" because it cannot analyze the
911        pattern in sufficient detail. The compile time test no longer happens when
912        PCRE is compiling a conditional subpattern, but actual runaway loops are
913        now caught at runtime (see 40 above).
914    
915    42. It seems that Perl allows any characters other than a closing parenthesis
916        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
917        has been changed to be the same.
918    
919    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
920        as not to get warnings when autogen.sh is called. Also changed
921        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
922    
923    44. To help people who use pcregrep to scan files containing exceedingly long
924        lines, the following changes have been made:
925    
926        (a) The default value of the buffer size parameter has been increased from
927            8K to 20K. (The actual buffer used is three times this size.)
928    
929        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
930            PCRE is built.
931    
932        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
933            to be set at run time.
934    
935        (d) Numerical values in pcregrep options can be followed by K or M, for
936            example --buffer-size=50K.
937    
938        (e) If a line being scanned overflows pcregrep's buffer, an error is now
939            given and the return code is set to 2.
940    
941    45. Add a pointer to the latest mark to the callout data block.
942    
943    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
944        partial match of an empty string instead of no match. This was specific to
945        the use of ".".
946    
947    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
948        complete match instead of a partial match. This bug was dependent on both
949        the PCRE_UTF8 and PCRE_DOTALL options being set.
950    
951    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
952        starting byte set, because \b was not being ignored.
953    
954    
955    Version 8.12 15-Jan-2011
956    ------------------------
957    
958    1.  Fixed some typos in the markup of the man pages, and wrote a script that
959        checks for such things as part of the documentation building process.
960    
961    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
962        --match-limit and --recursion-limit options (added for 8.11). In
963        particular, this made one of the standard tests fail. (The integer value
964        went into the wrong half of a long int.)
965    
966    3.  If the --colour option was given to pcregrep with -v (invert match), it
967        did strange things, either producing crazy output, or crashing. It should,
968        of course, ignore a request for colour when reporting lines that do not
969        match.
970    
971    4.  Another pcregrep bug caused similar problems if --colour was specified with
972        -M (multiline) and the pattern match finished with a line ending.
973    
974    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
975        matched in multiline mode, the following line was shown as part of the
976        match. This seems wrong, so I have changed it.
977    
978    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
979        the check for further matches in the same line (so they could be coloured)
980        to overrun the end of the current line. If another match was found, it was
981        incorrectly shown (and then shown again when found in the next line).
982    
983    7.  If pcregrep was compiled under Windows, there was a reference to the
984        function pcregrep_exit() before it was defined. I am assuming this was
985        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
986        reported by a user. I've moved the definition above the reference.
987    
988    
989    Version 8.11 10-Dec-2010
990    ------------------------
991    
992    1.  (*THEN) was not working properly if there were untried alternatives prior
993        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
994        backtracked to try for "b" instead of moving to the next alternative branch
995        at the same level (in this case, to look for "c"). The Perl documentation
996        is clear that when (*THEN) is backtracked onto, it goes to the "next
997        alternative in the innermost enclosing group".
998    
999    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1000        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1001        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1002        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1003        (*THEN).
1004    
1005    3.  If \s appeared in a character class, it removed the VT character from
1006        the class, even if it had been included by some previous item, for example
1007        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1008        of \s, but is part of the POSIX "space" class.)
1009    
1010    4.  A partial match never returns an empty string (because you can always
1011        match an empty string at the end of the subject); however the checking for
1012        an empty string was starting at the "start of match" point. This has been
1013        changed to the "earliest inspected character" point, because the returned
1014        data for a partial match starts at this character. This means that, for
1015        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1016        (previously it gave "no match").
1017    
1018    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1019        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1020        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1021        has an implication that the given string is incomplete (because a partial
1022        match is preferred over a full match). For this reason, these items now
1023        give a partial match in this situation. [Aside: previously, the one case
1024        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1025        match rather than a full match, which was wrong by the old rules, but is
1026        now correct.]
1027    
1028    6.  There was a bug in the handling of #-introduced comments, recognized when
1029        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1030        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1031        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1032        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1033        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1034        places in pcre_compile().
1035    
1036    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1037        comments when looking ahead for named forward references to subpatterns,
1038        the only newline sequence it recognized was NL. It now handles newlines
1039        according to the set newline convention.
1040    
1041    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1042        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1043        cater for a lack of strerror(). These oversights have been fixed.
1044    
1045    9.  Added --match-limit and --recursion-limit to pcregrep.
1046    
1047    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1048    
1049    11. When the -o option was used, pcregrep was setting a return code of 1, even
1050        when matches were found, and --line-buffered was not being honoured.
1051    
1052    12. Added an optional parentheses number to the -o and --only-matching options
1053        of pcregrep.
1054    
1055    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1056        can match an empty string. The code to do it in pcretest and pcredemo
1057        needed fixing:
1058    
1059        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1060            only one byte after an empty string match just before CRLF (this case
1061            just got forgotten; "any" and "anycrlf" were OK).
1062    
1063        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1064            mode when an empty string match preceded an ASCII character followed by
1065            a non-ASCII character. (The code for advancing by one character rather
1066            than one byte was nonsense.)
1067    
1068        (c) The pcredemo.c sample program did not have any code at all to handle
1069            the cases when CRLF is a valid newline sequence.
1070    
1071    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1072        as a starting offset was within the subject string. There is now a new
1073        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1074        negative or greater than the length of the string. In order to test this,
1075        pcretest is extended to allow the setting of negative starting offsets.
1076    
1077    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1078        starting offset points to the beginning of a UTF-8 character was
1079        unnecessarily clumsy. I tidied it up.
1080    
1081    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1082        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1083    
1084    17. Nobody had reported that the --include_dir option, which was added in
1085        release 7.7 should have been called --include-dir (hyphen, not underscore)
1086        for compatibility with GNU grep. I have changed it to --include-dir, but
1087        left --include_dir as an undocumented synonym, and the same for
1088        --exclude-dir, though that is not available in GNU grep, at least as of
1089        release 2.5.4.
1090    
1091    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1092        characters from a string of bytes) have been redefined so as not to use
1093        loops, in order to improve performance in some environments. At the same
1094        time, I abstracted some of the common code into auxiliary macros to save
1095        repetition (this should not affect the compiled code).
1096    
1097    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1098        compile-time error is now given if \c is not followed by an ASCII
1099        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1100        different, and any byte value is allowed.)
1101    
1102    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1103        START_OPTIMIZE option, which is now allowed at compile time - but just
1104        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1105        to pcregrep and other applications that have no direct access to PCRE
1106        options. The new /Y option in pcretest sets this option when calling
1107        pcre_compile().
1108    
1109    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1110        back references. Groups containing recursive back references were forced to
1111        be atomic by that change, but in the case of named groups, the amount of
1112        memory required was incorrectly computed, leading to "Failed: internal
1113        error: code overflow". This has been fixed.
1114    
1115    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1116        pcretest.c, to avoid build problems in some Borland environments.
1117    
1118    
1119    Version 8.10 25-Jun-2010
1120    ------------------------
1121    
1122    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1123        THEN.
1124    
1125    2.  (*ACCEPT) was not working when inside an atomic group.
1126    
1127    3.  Inside a character class, \B is treated as a literal by default, but
1128        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1129        causes the error). The code is unchanged, but I tidied the documentation.
1130    
1131    4.  Inside a character class, PCRE always treated \R and \X as literals,
1132        whereas Perl faults them if its -w option is set. I have changed PCRE so
1133        that it faults them when PCRE_EXTRA is set.
1134    
1135    5.  Added support for \N, which always matches any character other than
1136        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1137    
1138    6.  When compiling pcregrep with newer versions of gcc which may have
1139        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1140        declared with attribute warn_unused_result" were given. Just casting the
1141        result to (void) does not stop the warnings; a more elaborate fudge is
1142        needed. I've used a macro to implement this.
1143    
1144    7.  Minor change to pcretest.c to avoid a compiler warning.
1145    
1146    8.  Added four artifical Unicode properties to help with an option to make
1147        \s etc use properties (see next item). The new properties are: Xan
1148        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1149    
1150    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1151        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1152        this option. Modified pcretest to add /W to test this facility. Added
1153        REG_UCP to make it available via the POSIX interface.
1154    
1155    10. Added --line-buffered to pcregrep.
1156    
1157    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1158        studied, and the match started with a letter with a code point greater than
1159        127 whose first byte was different to the first byte of the other case of
1160        the letter, the other case of this starting letter was not recognized
1161        (#976).
1162    
1163    12. If a pattern that was studied started with a repeated Unicode property
1164        test, for example, \p{Nd}+, there was the theoretical possibility of
1165        setting up an incorrect bitmap of starting bytes, but fortunately it could
1166        not have actually happened in practice until change 8 above was made (it
1167        added property types that matched character-matching opcodes).
1168    
1169    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1170        possible starting bytes for non-anchored patterns.
1171    
1172    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1173        \R, and also a number of cases that involve Unicode properties, both
1174        explicit and implicit when PCRE_UCP is set.
1175    
1176    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1177        input, it could crash or give wrong results if characters with values
1178        greater than 0xc0 were present in the subject string. (Detail: it assumed
1179        UTF-8 input when processing these items.)
1180    
1181    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1182        size_t is 64-bit (#991).
1183    
1184    17. Added a check for running out of memory when PCRE is compiled with
1185        --disable-stack-for-recursion (#990).
1186    
1187    18. If the last data line in a file for pcretest does not have a newline on
1188        the end, a newline was missing in the output.
1189    
1190    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1191        less than 128) in its various bitmaps. However, there is a facility for
1192        generating tables according to the current locale when PCRE is compiled. It
1193        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1194        characters, are recognized by isspace() and therefore were getting set in
1195        these tables, and indeed these tables seem to approximate to ISO 8859. This
1196        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1197        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1198        which of course cannot start UTF-8 characters. I have changed the code so
1199        that only real ASCII characters (less than 128) and the correct starting
1200        bytes for UTF-8 encodings are set for characters greater than 127 when in
1201        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1202        altogether.)
1203    
1204    20. Added the /T option to pcretest so as to be able to run tests with non-
1205        standard character tables, thus making it possible to include the tests
1206        used for 19 above in the standard set of tests.
1207    
1208    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1209        reference to a subpattern the other side of a comment that contains an
1210        opening parenthesis caused either an internal compiling error, or a
1211        reference to the wrong subpattern.
1212    
1213    
1214    Version 8.02 19-Mar-2010
1215    ------------------------
1216    
1217    1.  The Unicode data tables have been updated to Unicode 5.2.0.
1218    
1219    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1220        configured.
1221    
1222    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1223        original author of that file, following a query about its status.
1224    
1225    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1226        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1227    
1228    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1229        quantifier applied to a forward-referencing subroutine call, could compile
1230        incorrect code or give the error "internal error: previously-checked
1231        referenced subpattern not found".
1232    
1233    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1234        variables to point to external functions. For these systems, therefore,
1235        pcre_malloc etc. are now initialized to local functions that call the
1236        relevant global functions.
1237    
1238    7.  There were two entries missing in the vectors called coptable and poptable
1239        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1240        I've fixed the data, and added a kludgy way of testing at compile time that
1241        the lengths are correct (equal to the number of opcodes).
1242    
1243    8.  Following on from 7, I added a similar kludge to check the length of the
1244        eint vector in pcreposix.c.
1245    
1246    9.  Error texts for pcre_compile() are held as one long string to avoid too
1247        much relocation at load time. To find a text, the string is searched,
1248        counting zeros. There was no check for running off the end of the string,
1249        which could happen if a new error number was added without updating the
1250        string.
1251    
1252    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1253    
1254    11. \K was not working if it appeared in an atomic group or in a group that
1255        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1256        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1257        the assertion is positive, but not if it is negative.
1258    
1259    12. Change 11 fortuitously reduced the size of the stack frame used in the
1260        "match()" function of pcre_exec.c by one pointer. Forthcoming
1261        implementation of support for (*MARK) will need an extra pointer on the
1262        stack; I have reserved it now, so that the stack frame size does not
1263        decrease.
1264    
1265    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1266        item in branch that calls a recursion is a subroutine call - as in the
1267        second branch in the above example - was incorrectly given the compile-
1268        time error "recursive call could loop indefinitely" because pcre_compile()
1269        was not correctly checking the subroutine for matching a non-empty string.
1270    
1271    14. The checks for overrunning compiling workspace could trigger after an
1272        overrun had occurred. This is a "should never occur" error, but it can be
1273        triggered by pathological patterns such as hundreds of nested parentheses.
1274        The checks now trigger 100 bytes before the end of the workspace.
1275    
1276    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1277    
1278    
1279    Version 8.01 19-Jan-2010
1280    ------------------------
1281    
1282    1.  If a pattern contained a conditional subpattern with only one branch (in
1283        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1284        computed the wrong minimum data length (which is of course zero for such
1285        subpatterns). This could cause incorrect "no match" results.
1286    
1287    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1288        the pattern is reset in the first branch, pcre_compile() failed with
1289        "internal error: code overflow at offset...". This happened only when
1290        the reset was to the original external option setting. (An optimization
1291        abstracts leading options settings into an external setting, which was the
1292        cause of this.)
1293    
1294    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1295        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1296        assertion pattern did not match (meaning that the assertion was true), it
1297        was incorrectly treated as false if the SKIP had been reached during the
1298        matching. This also applied to assertions used as conditions.
1299    
1300    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
1301        assertion subpattern, including such a pattern used as a condition,
1302        unpredictable results occurred, instead of the error return
1303        PCRE_ERROR_DFA_UITEM.
1304    
1305    5.  The C++ GlobalReplace function was not working like Perl for the special
1306        situation when an empty string is matched. It now does the fancy magic
1307        stuff that is necessary.
1308    
1309    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1310        removed. (These were left over from very, very early versions of PCRE.)
1311    
1312    7.  Some cosmetic changes to the code to make life easier when compiling it
1313        as part of something else:
1314    
1315        (a) Change DEBUG to PCRE_DEBUG.
1316    
1317        (b) In pcre_compile(), rename the member of the "branch_chain" structure
1318            called "current" as "current_branch", to prevent a collision with the
1319            Linux macro when compiled as a kernel module.
1320    
1321        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1322            prevent a collision with the Linux macro when compiled as a kernel
1323            module.
1324    
1325    8.  In pcre_compile() there are some checks for integer overflows that used to
1326        cast potentially large values to (double). This has been changed to that
1327        when building, a check for int64_t is made, and if it is found, it is used
1328        instead, thus avoiding the use of floating point arithmetic. (There is no
1329        other use of FP in PCRE.) If int64_t is not found, the fallback is to
1330        double.
1331    
1332    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
1333        2005 (difference between two addresses compared to an unsigned value).
1334    
1335    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1336        custom one, because of the following reported problem in Windows:
1337    
1338          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1339              under Win32.
1340          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1341              therefore missing the function definition.
1342          - The compiler thus generates a "C" signature for the test function.
1343          - The linker fails to find the "C" function.
1344          - PCRE fails to configure if asked to do so against libbz2.
1345    
1346    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1347        messages were output:
1348    
1349          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1350          rerunning libtoolize, to keep the correct libtool macros in-tree.
1351          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1352    
1353        I have done both of these things.
1354    
1355    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1356        most of the time, it *can* run out if it is given a pattern that contains a
1357        runaway infinite recursion. I updated the discussion in the pcrestack man
1358        page.
1359    
1360    13. Now that we have gone to the x.xx style of version numbers, the minor
1361        version may start with zero. Using 08 or 09 is a bad idea because users
1362        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1363        interpreted as invalid octal numbers. I've updated the previous comment in
1364        configure.ac, and also added a check that gives an error if 08 or 09 are
1365        used.
1366    
1367    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1368        causing partial matching to fail when the end of the subject matched \W
1369        in a UTF-8 pattern where \W was quantified with a minimum of 3.
1370    
1371    15. There were some discrepancies between the declarations in pcre_internal.h
1372        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1373        their definitions. The declarations used "const uschar *" and the
1374        definitions used USPTR. Even though USPTR is normally defined as "const
1375        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1376        reported that: "This difference in casting confuses some C++ compilers, for
1377        example, SunCC recognizes above declarations as different functions and
1378        generates broken code for hbpcre." I have changed the declarations to use
1379        USPTR.
1380    
1381    16. GNU libtool is named differently on some systems. The autogen.sh script now
1382        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1383        (FreeBSD).
1384    
1385    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1386        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1387        comment: "Figure out how to create a longlong from a string: strtoll and
1388        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1389        instance, but it only takes 2 args instead of 3!"
1390    
1391    18. A subtle bug concerned with back references has been fixed by a change of
1392        specification, with a corresponding code fix. A pattern such as
1393        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1394        refers, was giving matches when it shouldn't. For example, xa=xaaa would
1395        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1396        same bug. Such groups have to be quantified to be useful, or contained
1397        inside another quantified group. (If there's no repetition, the reference
1398        can never match.) The problem arises because, having left the group and
1399        moved on to the rest of the pattern, a later failure that backtracks into
1400        the group uses the captured value from the final iteration of the group
1401        rather than the correct earlier one. I have fixed this in PCRE by forcing
1402        any group that contains a reference to itself to be an atomic group; that
1403        is, there cannot be any backtracking into it once it has completed. This is
1404        similar to recursive and subroutine calls.
1405    
1406    
1407    Version 8.00 19-Oct-09
1408    ----------------------
1409    
1410    1.  The table for translating pcre_compile() error codes into POSIX error codes
1411        was out-of-date, and there was no check on the pcre_compile() error code
1412        being within the table. This could lead to an OK return being given in
1413        error.
1414    
1415    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1416        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1417        in a Windows environment.
1418    
1419    3.  The pcregrep --count option prints the count for each file even when it is
1420        zero, as does GNU grep. However, pcregrep was also printing all files when
1421        --files-with-matches was added. Now, when both options are given, it prints
1422        counts only for those files that have at least one match. (GNU grep just
1423        prints the file name in this circumstance, but including the count seems
1424        more useful - otherwise, why use --count?) Also ensured that the
1425        combination -clh just lists non-zero counts, with no names.
1426    
1427    4.  The long form of the pcregrep -F option was incorrectly implemented as
1428        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1429        but it seems right to fix it, and I didn't think it was worth preserving
1430        the old behaviour.
1431    
1432    5.  The command line items --regex=pattern and --regexp=pattern were not
1433        recognized by pcregrep, which required --regex pattern or --regexp pattern
1434        (with a space rather than an '='). The man page documented the '=' forms,
1435        which are compatible with GNU grep; these now work.
1436    
1437    6.  No libpcreposix.pc file was created for pkg-config; there was just
1438        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1439    
1440    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1441        when UCP support is not needed, by modifying the Python script that
1442        generates it from Unicode data files. This should not matter if the module
1443        is correctly used as a library, but I received one complaint about 50K of
1444        unwanted data. My guess is that the person linked everything into his
1445        program rather than using a library. Anyway, it does no harm.
1446    
1447    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1448        was a minimum greater than 1 for a wide character in a possessive
1449        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1450        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1451        character. Chaos in the form of incorrect output or a compiling loop could
1452        result.
1453    
1454    9.  The restrictions on what a pattern can contain when partial matching is
1455        requested for pcre_exec() have been removed. All patterns can now be
1456        partially matched by this function. In addition, if there are at least two
1457        slots in the offset vector, the offset of the earliest inspected character
1458        for the match and the offset of the end of the subject are set in them when
1459        PCRE_ERROR_PARTIAL is returned.
1460    
1461    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1462        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1463        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1464        and may be more useful for multi-segment matching.
1465    
1466    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1467        used to be given if ever the end of the subject was reached; now it is
1468        given only if matching could not proceed because another character was
1469        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1470        string "Z", which now yields "no match" instead of "partial match". In the
1471        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1472        final character ended with (*FAIL).
1473    
1474    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1475        if the pattern had a "must contain" character that was already found in the
1476        earlier partial match, unless partial matching was again requested. For
1477        example, with the pattern /dog.(body)?/, the "must contain" character is
1478        "g". If the first part-match was for the string "dog", restarting with
1479        "sbody" failed. This bug has been fixed.
1480    
1481    13. The string returned by pcre_dfa_exec() after a partial match has been
1482        changed so that it starts at the first inspected character rather than the
1483        first character of the match. This makes a difference only if the pattern
1484        starts with a lookbehind assertion or \b or \B (\K is not supported by
1485        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1486        matching functions compatible, and I think it's the right thing to do.
1487    
1488    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1489        so that the demonstration program is easily available in environments where
1490        PCRE has not been installed from source.
1491    
1492    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1493        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1494        library.
1495    
1496    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1497        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1498        is not the first non-POSIX option to be added. Clearly some people find
1499        these options useful.
1500    
1501    17. If a caller to the POSIX matching function regexec() passes a non-zero
1502        value for nmatch with a NULL value for pmatch, the value of
1503        nmatch is forced to zero.
1504    
1505    18. RunGrepTest did not have a test for the availability of the -u option of
1506        the diff command, as RunTest does. It now checks in the same way as
1507        RunTest, and also checks for the -b option.
1508    
1509    19. If an odd number of negated classes containing just a single character
1510        interposed, within parentheses, between a forward reference to a named
1511        subpattern and the definition of the subpattern, compilation crashed with
1512        an internal error, complaining that it could not find the referenced
1513        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1514        [The bug was that it was starting one character too far in when skipping
1515        over the character class, thus treating the ] as data rather than
1516        terminating the class. This meant it could skip too much.]
1517    
1518    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1519        /g option in pcretest when the pattern contains \K, which makes it possible
1520        to have an empty string match not at the start, even when the pattern is
1521        anchored. Updated pcretest and pcredemo to use this option.
1522    
1523    21. If the maximum number of capturing subpatterns in a recursion was greater
1524        than the maximum at the outer level, the higher number was returned, but
1525        with unset values at the outer level. The correct (outer level) value is
1526        now given.
1527    
1528    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1529        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1530        make it do so. The string so far is captured, making this feature
1531        compatible with Perl.
1532    
1533    23. The tests have been re-organized, adding tests 11 and 12, to make it
1534        possible to check the Perl 5.10 features against Perl 5.10.
1535    
1536    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1537        pattern matches a fixed length string. PCRE did not allow this; now it
1538        does. Neither allows recursion.
1539    
1540    25. I finally figured out how to implement a request to provide the minimum
1541        length of subject string that was needed in order to match a given pattern.
1542        (It was back references and recursion that I had previously got hung up
1543        on.) This code has now been added to pcre_study(); it finds a lower bound
1544        to the length of subject needed. It is not necessarily the greatest lower
1545        bound, but using it to avoid searching strings that are too short does give
1546        some useful speed-ups. The value is available to calling programs via
1547        pcre_fullinfo().
1548    
1549    26. While implementing 25, I discovered to my embarrassment that pcretest had
1550        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1551        study optimizations had never been tested with that matching function.
1552        Oops. What is worse, even when it was passed study data, there was a bug in
1553        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1554        were also very few tests of studied patterns with pcre_dfa_exec().
1555    
1556    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1557        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1558        on the other side of the coin, they are no longer allowed to have different
1559        names, because these cannot be distinguished in PCRE, and this has caused
1560        confusion. (This is a difference from Perl.)
1561    
1562    28. When duplicate subpattern names are present (necessarily with different
1563        numbers, as required by 27 above), and a test is made by name in a
1564        conditional pattern, either for a subpattern having been matched, or for
1565        recursion in such a pattern, all the associated numbered subpatterns are
1566        tested, and the overall condition is true if the condition is true for any
1567        one of them. This is the way Perl works, and is also more like the way
1568        testing by number works.
1569    
1570    
1571    Version 7.9 11-Apr-09
1572    ---------------------
1573    
1574    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1575        (pcretest), all targets were linked against these libraries. This included
1576        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1577        libraries. This caused unwanted dependencies to be created. This problem
1578        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1579        pcretest is linked with readline.
1580    
1581    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1582        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1583        moved outside it again, because FALSE and TRUE are already defined in AIX,
1584        but BOOL is not.
1585    
1586    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1587        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1588    
1589    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1590        hyphens) following file names and line numbers when outputting matching
1591        lines. This is not true; no spaces are inserted. I have also clarified the
1592        wording for the --colour (or --color) option.
1593    
1594    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1595        was not coloured; this is different to GNU grep, so I have changed it to be
1596        the same.
1597    
1598    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1599        each matching line was coloured. Now it goes on to look for further matches
1600        of any of the test patterns, which is the same behaviour as GNU grep.
1601    
1602    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1603        doesn't make sense to accept an empty string match in pcregrep, so I have
1604        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1605        seems to be how GNU grep behaves.
1606    
1607    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1608        start or after a newline", because the conditional assertion was not being
1609        correctly handled. The rule now is that both the assertion and what follows
1610        in the first alternative must satisfy the test.
1611    
1612    9.  If auto-callout was enabled in a pattern with a conditional group whose
1613        condition was an assertion, PCRE could crash during matching, both with
1614        pcre_exec() and pcre_dfa_exec().
1615    
1616    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1617        used for matching.
1618    
1619    11. Unicode property support in character classes was not working for
1620        characters (bytes) greater than 127 when not in UTF-8 mode.
1621    
1622    12. Added the -M command line option to pcretest.
1623    
1624    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1625    
1626    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1627    
1628    16. Added comments and documentation about mis-use of no_arg in the C++
1629        wrapper.
1630    
1631    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1632        from Martin Jerabek that uses macro names for all relevant character and
1633        string constants.
1634    
1635    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1636        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1637        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1638        these, but not everybody uses configure.
1639    
1640    19. A conditional group that had only one branch was not being correctly
1641        recognized as an item that could match an empty string. This meant that an
1642        enclosing group might also not be so recognized, causing infinite looping
1643        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1644        with the subject "ab", where knowledge that the repeated group can match
1645        nothing is needed in order to break the loop.
1646    
1647    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1648        exec(), but without supplying a callout function, matching went wrong.
1649    
1650    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1651        leak if the size of the offset vector was greater than 30. When the vector
1652        is smaller, the saved offsets during recursion go onto a local stack
1653        vector, but for larger vectors malloc() is used. It was failing to free
1654        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1655        error, in fact).
1656    
1657    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1658        heapframe that is used only when UTF-8 support is enabled. This caused no
1659        problem, but was untidy.
1660    
1661    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1662        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1663        included within another project.
1664    
1665    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1666        slightly modified by me:
1667    
1668          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1669              not building pcregrep.
1670    
1671          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1672              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1673    
1674    25. Forward references, both numeric and by name, in patterns that made use of
1675        duplicate group numbers, could behave incorrectly or give incorrect errors,
1676        because when scanning forward to find the reference group, PCRE was not
1677        taking into account the duplicate group numbers. A pattern such as
1678        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1679    
1680    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1681        the feature of a custom pointer more persuasive (as requested by a user).
1682    
1683    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1684        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1685        pre-defined.
1686    
1687    28. Added support for (*UTF8) at the start of a pattern.
1688    
1689    29. Arrange for flags added by the "release type" setting in CMake to be shown
1690        in the configuration summary.
1691    
1692    
1693    Version 7.8 05-Sep-08
1694  ---------------------  ---------------------
1695    
1696  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
1697      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1698      stage table and inline lookup instead of a function, giving speed ups of 2      stage table and inline lookup instead of a function, giving speed ups of 2
1699      to 5 times on some simple patterns that I tested. Permission was given to      to 5 times on some simple patterns that I tested. Permission was given to
1700      distribute the MultiStage2.py script that generates the tables (it's not in      distribute the MultiStage2.py script that generates the tables (it's not in
1701      the tarball, but is in the Subversion repository).      the tarball, but is in the Subversion repository).
1702    
1703    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1704        scripts.
1705    
1706    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1707        a group with a zero qualifier. The result of the study could be incorrect,
1708        or the function might crash, depending on the pattern.
1709    
1710    4.  Caseless matching was not working for non-ASCII characters in back
1711        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1712        It now works when Unicode Property Support is available.
1713    
1714    5.  In pcretest, an escape such as \x{de} in the data was always generating
1715        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1716        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1717        truncation.
1718    
1719    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1720    
1721    7.  Added two (int) casts to pcregrep when printing the difference of two
1722        pointers, in case they are 64-bit values.
1723    
1724    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1725        test 2 if it fails.
1726    
1727    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1728        and a #define of that name to empty if it is not externally set. This is to
1729        allow users of MSVC to set it if necessary.
1730    
1731    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1732        the convenience functions in the pcre_get.c source file.
1733    
1734    11. An option change at the start of a pattern that had top-level alternatives
1735        could cause overwriting and/or a crash. This command provoked a crash in
1736        some environments:
1737    
1738          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1739    
1740        This potential security problem was recorded as CVE-2008-2371.
1741    
1742    12. For a pattern where the match had to start at the beginning or immediately
1743        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1744        pcre_dfa_exec() could read past the end of the passed subject if there was
1745        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1746        pcretest so that it places the subject at the end of its malloc-ed buffer.
1747    
1748    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1749        exec() might read past the end of the data buffer in UTF-8 mode.
1750    
1751    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1752        the data contained the byte 0x85 as part of a UTF-8 character within its
1753        first line. This applied both to normal and DFA matching.
1754    
1755    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1756        /^[^d]*?$/8 failed to match "abc".
1757    
1758    16. Added a missing copyright notice to pcrecpp_internal.h.
1759    
1760    17. Make it more clear in the documentation that values returned from
1761        pcre_exec() in ovector are byte offsets, not character counts.
1762    
1763    18. Tidied a few places to stop certain compilers from issuing warnings.
1764    
1765    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1766        supplied by Stefan Weber. I made a further small update for 7.8 because
1767        there is a change of source arrangements: the pcre_searchfuncs.c module is
1768        replaced by pcre_ucd.c.
1769    
1770    
1771  Version 7.7 07-May-08  Version 7.7 07-May-08

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