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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  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    
64    Version 8.32 30-November-2012
65    -----------------------------
66    
67    1.  Improved JIT compiler optimizations for first character search and single
68        character iterators.
69    
70    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
71        Patch by Daniel Richard G.
72    
73    3.  Single character iterator optimizations in the JIT compiler.
74    
75    4.  Improved JIT compiler optimizations for character ranges.
76    
77    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
78        Reported by Giuseppe D'Angelo.
79    
80    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
81        of a line, was being set incorrectly in cases where .* appeared inside
82        atomic brackets at the start of a pattern, or where there was a subsequent
83        *PRUNE or *SKIP.
84    
85    7.  Improved instruction cache flush for POWER/PowerPC.
86        Patch by Daniel Richard G.
87    
88    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
89        grep:
90    
91        (a) There is now no limit to the number of patterns to be matched.
92    
93        (b) An error is given if a pattern is too long.
94    
95        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
96            are now supported.
97    
98        (d) --exclude-from and --include-from (multiple use) have been added.
99    
100        (e) Exclusions and inclusions now apply to all files and directories, not
101            just to those obtained from scanning a directory recursively.
102    
103        (f) Multiple uses of -f and --file-list are now supported.
104    
105        (g) In a Windows environment, the default for -d has been changed from
106            "read" (the GNU grep default) to "skip", because otherwise the presence
107            of a directory in the file list provokes an error.
108    
109        (h) The documentation has been revised and clarified in places.
110    
111    9.  Improve the matching speed of capturing brackets.
112    
113    10. Changed the meaning of \X so that it now matches a Unicode extended
114        grapheme cluster.
115    
116    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
117        out POSIX threads when JIT support is configured.
118    
119    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
120    
121    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
122        structure could go wrong in environments where size_t is not the same size
123        as int.
124    
125    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
126        set.
127    
128    15. The EBCDIC support had decayed; later updates to the code had included
129        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
130        general tidy up of EBCDIC-related issues, and the documentation was also
131        not quite right. There is now a test that can be run on ASCII systems to
132        check some of the EBCDIC-related things (but is it not a full test).
133    
134    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
135        in a small tidy to the code.
136    
137    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
138    
139    18. If the --only-matching (-o) option in pcregrep is specified multiple
140        times, each one causes appropriate output. For example, -o1 -o2 outputs the
141        substrings matched by the 1st and 2nd capturing parentheses. A separating
142        string can be specified by --om-separator (default empty).
143    
144    19. Improving the first n character searches.
145    
146    20. Turn case lists for horizontal and vertical white space into macros so that
147        they are defined only once.
148    
149    21. This set of changes together give more compatible Unicode case-folding
150        behaviour for characters that have more than one other case when UCP
151        support is available.
152    
153        (a) The Unicode property table now has offsets into a new table of sets of
154            three or more characters that are case-equivalent. The MultiStage2.py
155            script that generates these tables (the pcre_ucd.c file) now scans
156            CaseFolding.txt instead of UnicodeData.txt for character case
157            information.
158    
159        (b) The code for adding characters or ranges of characters to a character
160            class has been abstracted into a generalized function that also handles
161            case-independence. In UTF-mode with UCP support, this uses the new data
162            to handle characters with more than one other case.
163    
164        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
165            whose other case is greater than 256 are now correctly matched
166            caselessly. Previously, the high codepoint matched the low one, but not
167            vice versa.
168    
169        (d) The processing of \h, \H, \v, and \ in character classes now makes use
170            of the new class addition function, using character lists defined as
171            macros alongside the case definitions of 20 above.
172    
173        (e) Caseless back references now work with characters that have more than
174            one other case.
175    
176        (f) General caseless matching of characters with more than one other case
177            is supported.
178    
179    22. Unicode character properties were updated from Unicode 6.2.0
180    
181    23. Improved CMake support under Windows. Patch by Daniel Richard G.
182    
183    24. Add support for 32-bit character strings, and UTF-32
184    
185    25. Major JIT compiler update (code refactoring and bugfixing).
186        Experimental Sparc 32 support is added.
187    
188    26. Applied a modified version of Daniel Richard G's patch to create
189        pcre.h.generic and config.h.generic by "make" instead of in the
190        PrepareRelease script.
191    
192    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
193        pcre_compile.c when checking for a zero character.
194    
195    28. Introducing a native interface for JIT. Through this interface, the compiled
196        machine code can be directly executed. The purpose of this interface is to
197        provide fast pattern matching, so several sanity checks are not performed.
198        However, feature tests are still performed. The new interface provides
199        1.4x speedup compared to the old one.
200    
201    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
202        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
203        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
204    
205    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
206        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
207        the "old" RFC 2279). Instead, it ended up passing a negative length to
208        pcre_exec().
209    
210    31. Add support for GCC's visibility feature to hide internal functions.
211    
212    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
213        "unknown -C option" after outputting 0 or 1.
214    
215    33. There is now support for generating a code coverage report for the test
216        suite in environments where gcc is the compiler and lcov is installed. This
217        is mainly for the benefit of the developers.
218    
219    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
220        unaddressable using valgrind annotations, allowing valgrind to detect
221        invalid memory accesses. This is mainly for the benefit of the developers.
222    
223    25. (*UTF) can now be used to start a pattern in any of the three libraries.
224    
225    26. Give configure error if --enable-cpp but no C++ compiler found.
226    
227    
228    Version 8.31 06-July-2012
229    -------------------------
230    
231    1.  Fixing a wrong JIT test case and some compiler warnings.
232    
233    2.  Removed a bashism from the RunTest script.
234    
235    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
236        to unsigned type, result still unsigned" that was given by an MS compiler
237        on encountering the code "-sizeof(xxx)".
238    
239    4.  Partial matching support is added to the JIT compiler.
240    
241    5.  Fixed several bugs concerned with partial matching of items that consist
242        of more than one character:
243    
244        (a) /^(..)\1/ did not partially match "aba" because checking references was
245            done on an "all or nothing" basis. This also applied to repeated
246            references.
247    
248        (b) \R did not give a hard partial match if \r was found at the end of the
249            subject.
250    
251        (c) \X did not give a hard partial match after matching one or more
252            characters at the end of the subject.
253    
254        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
255            a partial match for the string "\r".
256    
257        (e) When newline was set to CRLF, the metacharacter "." did not recognize
258            a partial match for a CR character at the end of the subject string.
259    
260    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
261        running pcretest, the text "(JIT)" added to the output whenever JIT is
262        actually used to run the match.
263    
264    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
265        or /S+[+] with a digit between 1 and 7.
266    
267    8.  OP_NOT now supports any UTF character not just single-byte ones.
268    
269    9.  (*MARK) control verb is now supported by the JIT compiler.
270    
271    10. The command "./RunTest list" lists the available tests without actually
272        running any of them. (Because I keep forgetting what they all are.)
273    
274    11. Add PCRE_INFO_MAXLOOKBEHIND.
275    
276    12. Applied a (slightly modified) user-supplied patch that improves performance
277        when the heap is used for recursion (compiled with --disable-stack-for-
278        recursion). Instead of malloc and free for each heap frame each time a
279        logical recursion happens, frames are retained on a chain and re-used where
280        possible. This sometimes gives as much as 30% improvement.
281    
282    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
283        call.
284    
285    14. As documented, (*COMMIT) is now confined to within a positive assertion.
286    
287    15. It is now possible to link pcretest with libedit as an alternative to
288        libreadline.
289    
290    16. (*COMMIT) control verb is now supported by the JIT compiler.
291    
292    17. The Unicode data tables have been updated to Unicode 6.1.0.
293    
294    18. Added --file-list option to pcregrep.
295    
296    19. Added binary file support to pcregrep, including the -a, --binary-files,
297        -I, and --text options.
298    
299    20. The madvise function is renamed for posix_madvise for QNX compatibility
300        reasons. Fixed by Giuseppe D'Angelo.
301    
302    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
303    
304    22. Changed the option for creating symbolic links for 16-bit man pages from
305        -s to -sf so that re-installing does not cause issues.
306    
307    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
308    
309    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
310        matches in certain environments (the workspace was not being correctly
311        retained). Also added to pcre_dfa_exec() a simple plausibility check on
312        some of the workspace data at the beginning of a restart.
313    
314    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
315        was not doing so when it should - probably a typo introduced by SVN 528
316        (change 8.10/14).
317    
318    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
319        \w+ when the character tables indicated that \x{c4} was a word character.
320        There were several related cases, all because the tests for doing a table
321        lookup were testing for characters less than 127 instead of 255.
322    
323    27. If a pattern contains capturing parentheses that are not used in a match,
324        their slots in the ovector are set to -1. For those that are higher than
325        any matched groups, this happens at the end of processing. In the case when
326        there were back references that the ovector was too small to contain
327        (causing temporary malloc'd memory to be used during matching), and the
328        highest capturing number was not used, memory off the end of the ovector
329        was incorrectly being set to -1. (It was using the size of the temporary
330        memory instead of the true size.)
331    
332    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
333        ovector size, it uses memory at the end of the block that it has got.
334    
335    29. Check for an overlong MARK name and give an error at compile time. The
336        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
337    
338    30. JIT compiler update.
339    
340    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
341        Rill for the patch.
342    
343    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
344    
345    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
346    
347    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
348        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
349        was enabled.
350    
351    35. Improve JIT code generation for greedy plus quantifier.
352    
353    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
354        1 to "aa" instead of to an empty string. The bug affected repeated groups
355        that could potentially match an empty string.
356    
357    37. Optimizing single character iterators in JIT.
358    
359    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
360        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
361        codepoints that are too big for the mode are faulted, and in a UTF mode,
362        disallowed codepoints are also faulted.
363    
364    39. If PCRE was compiled with UTF support, in three places in the DFA
365        matcher there was code that should only have been obeyed in UTF mode, but
366        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
367        processing when bytes with values greater than 127 were present. In 16-bit
368        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
369        both cases the values are those that cannot be the first data item in a UTF
370        character. The three items that might have provoked this were recursions,
371        possessively repeated groups, and atomic groups.
372    
373    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
374        and pcregrep, because some OS require shared objects to be explicitly
375        passed to ld, causing the link step to fail if they are not.
376    
377    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
378        mode, patterns that started with \h* or \R* might be incorrectly matched.
379    
380    
381    Version 8.30 04-February-2012
382    -----------------------------
383    
384    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
385        name is defined in ctype.h.
386    
387    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
388        only in quite long subpatterns.
389    
390    3.  Removed the function pcre_info(), which has been obsolete and deprecated
391        since it was replaced by pcre_fullinfo() in February 2000.
392    
393    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
394        match a (*MARK), and the match failed at the start of the subject, a
395        reference to memory before the start of the subject could occur. This bug
396        was introduced by fix 17 of release 8.21.
397    
398    5.  A reference to an unset group with zero minimum repetition was giving
399        totally wrong answers (in non-JavaScript-compatibility mode). For example,
400        /(another)?(\1?)test/ matched against "hello world test". This bug was
401        introduced in release 8.13.
402    
403    6.  Add support for 16-bit character strings (a large amount of work involving
404        many changes and refactorings).
405    
406    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
407        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
408        from a file.
409    
410    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
411        rounding is not applied in this particular case).
412    
413    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
414        if they appear, or are escaped, in patterns.
415    
416    10. Get rid of a number of -Wunused-but-set-variable warnings.
417    
418    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
419        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
420        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
421        also returns the mark "x". This bug applied to capturing parentheses,
422        non-capturing parentheses, and atomic parentheses. It also applied to some
423        assertions.
424    
425    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
426        information out of configure.ac instead of relying on pcre.h.generic, which
427        is not stored in the repository.
428    
429    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
430        -lreadline.
431    
432    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
433    
434    15. Applied Graycode's patch to put the top-level frame on the stack rather
435        than the heap when not using the stack for recursion. This gives a
436        performance improvement in many cases when recursion is not deep.
437    
438    16. Experimental code added to "pcretest -C" to output the stack frame size.
439    
440    
441    Version 8.21 12-Dec-2011
442    ------------------------
443    
444    1.  Updating the JIT compiler.
445    
446    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
447        are added as well.
448    
449    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
450        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
451        calling _pcre_jit_exec. Some extra comments are added.
452    
453    4.  (*MARK) settings inside atomic groups that do not contain any capturing
454        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
455        was introduced by change 18 for 8.20.
456    
457    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
458        ECMA-262 standard.
459    
460    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
461        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
462        This bug was probably introduced by change 9 of 8.13.
463    
464    7.  While fixing 6 above, I noticed that a number of other items were being
465        incorrectly rejected as "not fixed length". This arose partly because newer
466        opcodes had not been added to the fixed-length checking code. I have (a)
467        corrected the bug and added tests for these items, and (b) arranged for an
468        error to occur if an unknown opcode is encountered while checking for fixed
469        length instead of just assuming "not fixed length". The items that were
470        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
471        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
472        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
473    
474    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
475        being incorrectly compiled and would have given unpredicatble results.
476    
477    9.  A possessively repeated subpattern with minimum repeat count greater than
478        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
479        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
480        the first (A) could occur when it should not.
481    
482    10. Add a cast and remove a redundant test from the code.
483    
484    11. JIT should use pcre_malloc/pcre_free for allocation.
485    
486    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
487        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
488        is anything other than /usr, -L is still shown).
489    
490    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
491    
492    14. Perl does not support \N without a following name in a [] class; PCRE now
493        also gives an error.
494    
495    15. If a forward reference was repeated with an upper limit of around 2000,
496        it caused the error "internal error: overran compiling workspace". The
497        maximum number of forward references (including repeats) was limited by the
498        internal workspace, and dependent on the LINK_SIZE. The code has been
499        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
500        the default depends on LINK_SIZE. There is a new upper limit (for safety)
501        of around 200,000 forward references. While doing this, I also speeded up
502        the filling in of repeated forward references.
503    
504    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
505        incorrectly expecting the subject to contain another "a" after the start.
506    
507    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
508        in the match, the SKIP should be ignored. This was not happening; instead
509        the SKIP was being treated as NOMATCH. For patterns such as
510        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
511        tested.
512    
513    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
514        now much more compatible with Perl, in particular in cases where the result
515        is a non-match for a non-anchored pattern. For example, if
516        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
517        "m", where previously it did not return a name. A side effect of this
518        change is that for partial matches, the last encountered mark name is
519        returned, as for non matches. A number of tests that were previously not
520        Perl-compatible have been moved into the Perl-compatible test files. The
521        refactoring has had the pleasing side effect of removing one argument from
522        the match() function, thus reducing its stack requirements.
523    
524    19. If the /S+ option was used in pcretest to study a pattern using JIT,
525        subsequent uses of /S (without +) incorrectly behaved like /S+.
526    
527    21. Retrieve executable code size support for the JIT compiler and fixing
528        some warnings.
529    
530    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
531        not work when the shorter character appeared right at the end of the
532        subject string.
533    
534    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
535        systems.
536    
537    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
538        output it when the /M option is used in pcretest.
539    
540    25. The CheckMan script was not being included in the distribution. Also, added
541        an explicit "perl" to run Perl scripts from the PrepareRelease script
542        because this is reportedly needed in Windows.
543    
544    26. If study data was being save in a file and studying had not found a set of
545        "starts with" bytes for the pattern, the data written to the file (though
546        never used) was taken from uninitialized memory and so caused valgrind to
547        complain.
548    
549    27. Updated RunTest.bat as provided by Sheri Pierce.
550    
551    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
552    
553    29. Computation of memory usage for the table of capturing group names was
554        giving an unnecessarily large value.
555    
556    
557    Version 8.20 21-Oct-2011
558    ------------------------
559    
560    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
561        a POSIX class. After further experiments with Perl, which convinced me that
562        Perl has bugs and confusions, a closing square bracket is no longer allowed
563        in a POSIX name. This bug also affected patterns with classes that started
564        with full stops.
565    
566    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
567        captured substring, but while checking the failing first alternative,
568        substring 1 is temporarily captured. If the output vector supplied to
569        pcre_exec() was not big enough for this capture, the yield of the function
570        was still zero ("insufficient space for captured substrings"). This cannot
571        be totally fixed without adding another stack variable, which seems a lot
572        of expense for a edge case. However, I have improved the situation in cases
573        such as /(a)(b)x|abc/ matched against "abc", where the return code
574        indicates that fewer than the maximum number of slots in the ovector have
575        been set.
576    
577    3.  Related to (2) above: when there are more back references in a pattern than
578        slots in the output vector, pcre_exec() uses temporary memory during
579        matching, and copies in the captures as far as possible afterwards. It was
580        using the entire output vector, but this conflicts with the specification
581        that only 2/3 is used for passing back captured substrings. Now it uses
582        only the first 2/3, for compatibility. This is, of course, another edge
583        case.
584    
585    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
586        main code base, and can be used by building with --enable-jit. When this is
587        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
588        runtime --no-jit option is given.
589    
590    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
591        ovector, the return from the function was zero, implying that there were
592        other matches that did not fit. The correct "exactly full" value is now
593        returned.
594    
595    6.  If a subpattern that was called recursively or as a subroutine contained
596        (*PRUNE) or any other control that caused it to give a non-standard return,
597        invalid errors such as "Error -26 (nested recursion at the same subject
598        position)" or even infinite loops could occur.
599    
600    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
601        computing the minimum length on reaching *ACCEPT, and so ended up with the
602        wrong value of 1 rather than 0. Further investigation indicates that
603        computing a minimum subject length in the presence of *ACCEPT is difficult
604        (think back references, subroutine calls), and so I have changed the code
605        so that no minimum is registered for a pattern that contains *ACCEPT.
606    
607    8.  If (*THEN) was present in the first (true) branch of a conditional group,
608        it was not handled as intended. [But see 16 below.]
609    
610    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
611        Sheri Pierce.
612    
613    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
614        the first byte in a match must be "a".
615    
616    11. Change 17 for 8.13 increased the recursion depth for patterns like
617        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
618        pattern contains any instances of (*THEN). If it does not, the old
619        optimizations are restored. It would be nice to do this on a per-group
620        basis, but at the moment that is not feasible.
621    
622    12. In some environments, the output of pcretest -C is CRLF terminated. This
623        broke RunTest's code that checks for the link size. A single white space
624        character after the value is now allowed for.
625    
626    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
627        For "fr", it uses the Windows-specific input and output files.
628    
629    14. If (*THEN) appeared in a group that was called recursively or as a
630        subroutine, it did not work as intended. [But see next item.]
631    
632    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
633        pattern fragments (but not containing any | characters). If A and B are
634        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
635        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
636        D. In other words, Perl considers parentheses that do not contain any |
637        characters to be part of a surrounding alternative, whereas PCRE was
638        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
639        differently. PCRE now behaves in the same way as Perl, except in the case
640        of subroutine/recursion calls such as (?1) which have in any case always
641        been different (but PCRE had them first :-).
642    
643    16. Related to 15 above: Perl does not treat the | in a conditional group as
644        creating alternatives. Such a group is treated in the same way as an
645        ordinary group without any | characters when processing (*THEN). PCRE has
646        been changed to match Perl's behaviour.
647    
648    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
649        RunGrepTest script failed.
650    
651    18. Change 22 for version 13 caused atomic groups to use more stack. This is
652        inevitable for groups that contain captures, but it can lead to a lot of
653        stack use in large patterns. The old behaviour has been restored for atomic
654        groups that do not contain any capturing parentheses.
655    
656    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
657        suppress the check for a minimum subject length at run time. (If it was
658        given to pcre_exec() or pcre_dfa_exec() it did work.)
659    
660    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
661        fail to work when decoding hex characters in data strings in EBCDIC
662        environments.
663    
664    21. It appears that in at least one Mac OS environment, the isxdigit() function
665        is implemented as a macro that evaluates to its argument more than once,
666        contravening the C 90 Standard (I haven't checked a later standard). There
667        was an instance in pcretest which caused it to go wrong when processing
668        \x{...} escapes in subject strings. The has been rewritten to avoid using
669        things like p++ in the argument of isxdigit().
670    
671    
672    Version 8.13 16-Aug-2011
673    ------------------------
674    
675    1.  The Unicode data tables have been updated to Unicode 6.0.0.
676    
677    2.  Two minor typos in pcre_internal.h have been fixed.
678    
679    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
680        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
681        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
682    
683    4.  There were a number of related bugs in the code for matching backrefences
684        caselessly in UTF-8 mode when codes for the characters concerned were
685        different numbers of bytes. For example, U+023A and U+2C65 are an upper
686        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
687        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
688        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
689        2-byte code at the end of the subject (it thought there wasn't enough data
690        left).
691    
692    5.  Comprehensive information about what went wrong is now returned by
693        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
694        as the output vector has at least 2 elements. The offset of the start of
695        the failing character and a reason code are placed in the vector.
696    
697    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
698        now returned is for the first byte of the failing character, instead of the
699        last byte inspected. This is an incompatible change, but I hope it is small
700        enough not to be a problem. It makes the returned offset consistent with
701        pcre_exec() and pcre_dfa_exec().
702    
703    7.  pcretest now gives a text phrase as well as the error number when
704        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
705        failure, the offset and reason code are output.
706    
707    8.  When \R was used with a maximizing quantifier it failed to skip backwards
708        over a \r\n pair if the subsequent match failed. Instead, it just skipped
709        back over a single character (\n). This seems wrong (because it treated the
710        two characters as a single entity when going forwards), conflicts with the
711        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
712        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
713        has been changed.
714    
715    9.  Some internal refactoring has changed the processing so that the handling
716        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
717        time (the PCRE_DOTALL option was changed this way some time ago: version
718        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
719        which was always a bit of a fudge. It also means that there is one less
720        argument for the match() function, which reduces its stack requirements
721        slightly. This change also fixes an incompatibility with Perl: the pattern
722        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
723    
724    10. More internal refactoring has drastically reduced the number of recursive
725        calls to match() for possessively repeated groups such as (abc)++ when
726        using pcre_exec().
727    
728    11. While implementing 10, a number of bugs in the handling of groups were
729        discovered and fixed:
730    
731        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
732        (a|)*(?1) gave a compile-time internal error.
733        ((a|)+)+  did not notice that the outer group could match an empty string.
734        (^a|^)+   was not marked as anchored.
735        (.*a|.*)+ was not marked as matching at start or after a newline.
736    
737    12. Yet more internal refactoring has removed another argument from the match()
738        function. Special calls to this function are now indicated by setting a
739        value in a variable in the "match data" data block.
740    
741    13. Be more explicit in pcre_study() instead of relying on "default" for
742        opcodes that mean there is no starting character; this means that when new
743        ones are added and accidentally left out of pcre_study(), testing should
744        pick them up.
745    
746    14. The -s option of pcretest has been documented for ages as being an old
747        synonym of -m (show memory usage). I have changed it to mean "force study
748        for every regex", that is, assume /S for every regex. This is similar to -i
749        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
750        using it. It makes it easier to run collections of tests with and without
751        study enabled, and thereby test pcre_study() more easily. All the standard
752        tests are now run with and without -s (but some patterns can be marked as
753        "never study" - see 20 below).
754    
755    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
756        restoration of the capturing data to the outer values was not happening
757        correctly.
758    
759    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
760        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
761        pattern had matched an empty string, and so incorrectly returned a no
762        match.
763    
764    17. There was optimizing code for the last branch of non-capturing parentheses,
765        and also for the obeyed branch of a conditional subexpression, which used
766        tail recursion to cut down on stack usage. Unfortunately, now that there is
767        the possibility of (*THEN) occurring in these branches, tail recursion is
768        no longer possible because the return has to be checked for (*THEN). These
769        two optimizations have therefore been removed. [But see 8.20/11 above.]
770    
771    18. If a pattern containing \R was studied, it was assumed that \R always
772        matched two bytes, thus causing the minimum subject length to be
773        incorrectly computed because \R can also match just one byte.
774    
775    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
776        was incorrectly computed.
777    
778    20. If /S is present twice on a test pattern in pcretest input, it now
779        *disables* studying, thereby overriding the use of -s on the command line
780        (see 14 above). This is necessary for one or two tests to keep the output
781        identical in both cases.
782    
783    21. When (*ACCEPT) was used in an assertion that matched an empty string and
784        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
785    
786    22. When an atomic group that contained a capturing parenthesis was
787        successfully matched, but the branch in which it appeared failed, the
788        capturing was not being forgotten if a higher numbered group was later
789        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
790        group 1 to "a", when in fact it should be unset. This applied to multi-
791        branched capturing and non-capturing groups, repeated or not, and also to
792        positive assertions (capturing in negative assertions does not happen
793        in PCRE) and also to nested atomic groups.
794    
795    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
796        subject after a captured substring, to make it easier to tell which of a
797        number of identical substrings has been captured.
798    
799    24. The way atomic groups are processed by pcre_exec() has been changed so that
800        if they are repeated, backtracking one repetition now resets captured
801        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
802        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
803        "aaa". Previously, it would have been "a". As part of this code
804        refactoring, the way recursive calls are handled has also been changed.
805    
806    25. If an assertion condition captured any substrings, they were not passed
807        back unless some other capturing happened later. For example, if
808        (?(?=(a))a) was matched against "a", no capturing was returned.
809    
810    26. When studying a pattern that contained subroutine calls or assertions,
811        the code for finding the minimum length of a possible match was handling
812        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
813        group 1 called group 2 while simultaneously a separate group 2 called group
814        1). A stack overflow occurred in this case. I have fixed this by limiting
815        the recursion depth to 10.
816    
817    27. Updated RunTest.bat in the distribution to the version supplied by Tom
818        Fortmann. This supports explicit test numbers on the command line, and has
819        argument validation and error reporting.
820    
821    28. An instance of \X with an unlimited repeat could fail if at any point the
822        first character it looked at was a mark character.
823    
824    29. Some minor code refactoring concerning Unicode properties and scripts
825        should reduce the stack requirement of match() slightly.
826    
827    30. Added the '=' option to pcretest to check the setting of unused capturing
828        slots at the end of the pattern, which are documented as being -1, but are
829        not included in the return count.
830    
831    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
832        compiled something random. Now it gives a compile-time error (as does
833        Perl).
834    
835    32. A *MARK encountered during the processing of a positive assertion is now
836        recorded and passed back (compatible with Perl).
837    
838    33. If --only-matching or --colour was set on a pcregrep call whose pattern
839        had alternative anchored branches, the search for a second match in a line
840        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
841        matched the line "0102" twice. The same bug affected patterns that started
842        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
843        twice.
844    
845    34. Previously, PCRE did not allow quantification of assertions. However, Perl
846        does, and because of capturing effects, quantifying parenthesized
847        assertions may at times be useful. Quantifiers are now allowed for
848        parenthesized assertions.
849    
850    35. A minor code tidy in pcre_compile() when checking options for \R usage.
851    
852    36. \g was being checked for fancy things in a character class, when it should
853        just be a literal "g".
854    
855    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
856        appearance of a nested POSIX class supersedes an apparent external class.
857        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
858        unescaped square brackets may also appear as part of class names. For
859        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
860        more like Perl. (But see 8.20/1 above.)
861    
862    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
863        was because it thought it was \N{name}, which is not supported).
864    
865    39. Add minix to OS list not supporting the -S option in pcretest.
866    
867    40. PCRE tries to detect cases of infinite recursion at compile time, but it
868        cannot analyze patterns in sufficient detail to catch mutual recursions
869        such as ((?1))((?2)). There is now a runtime test that gives an error if a
870        subgroup is called recursively as a subpattern for a second time at the
871        same position in the subject string. In previous releases this might have
872        been caught by the recursion limit, or it might have run out of stack.
873    
874    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
875        happen only once. PCRE was, however incorrectly giving a compile time error
876        "recursive call could loop indefinitely" because it cannot analyze the
877        pattern in sufficient detail. The compile time test no longer happens when
878        PCRE is compiling a conditional subpattern, but actual runaway loops are
879        now caught at runtime (see 40 above).
880    
881    42. It seems that Perl allows any characters other than a closing parenthesis
882        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
883        has been changed to be the same.
884    
885    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
886        as not to get warnings when autogen.sh is called. Also changed
887        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
888    
889    44. To help people who use pcregrep to scan files containing exceedingly long
890        lines, the following changes have been made:
891    
892        (a) The default value of the buffer size parameter has been increased from
893            8K to 20K. (The actual buffer used is three times this size.)
894    
895        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
896            PCRE is built.
897    
898        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
899            to be set at run time.
900    
901        (d) Numerical values in pcregrep options can be followed by K or M, for
902            example --buffer-size=50K.
903    
904        (e) If a line being scanned overflows pcregrep's buffer, an error is now
905            given and the return code is set to 2.
906    
907    45. Add a pointer to the latest mark to the callout data block.
908    
909    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
910        partial match of an empty string instead of no match. This was specific to
911        the use of ".".
912    
913    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
914        complete match instead of a partial match. This bug was dependent on both
915        the PCRE_UTF8 and PCRE_DOTALL options being set.
916    
917    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
918        starting byte set, because \b was not being ignored.
919    
920    
921    Version 8.12 15-Jan-2011
922    ------------------------
923    
924    1.  Fixed some typos in the markup of the man pages, and wrote a script that
925        checks for such things as part of the documentation building process.
926    
927    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
928        --match-limit and --recursion-limit options (added for 8.11). In
929        particular, this made one of the standard tests fail. (The integer value
930        went into the wrong half of a long int.)
931    
932    3.  If the --colour option was given to pcregrep with -v (invert match), it
933        did strange things, either producing crazy output, or crashing. It should,
934        of course, ignore a request for colour when reporting lines that do not
935        match.
936    
937    4.  Another pcregrep bug caused similar problems if --colour was specified with
938        -M (multiline) and the pattern match finished with a line ending.
939    
940    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
941        matched in multiline mode, the following line was shown as part of the
942        match. This seems wrong, so I have changed it.
943    
944    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
945        the check for further matches in the same line (so they could be coloured)
946        to overrun the end of the current line. If another match was found, it was
947        incorrectly shown (and then shown again when found in the next line).
948    
949    7.  If pcregrep was compiled under Windows, there was a reference to the
950        function pcregrep_exit() before it was defined. I am assuming this was
951        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
952        reported by a user. I've moved the definition above the reference.
953    
954    
955    Version 8.11 10-Dec-2010
956    ------------------------
957    
958    1.  (*THEN) was not working properly if there were untried alternatives prior
959        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
960        backtracked to try for "b" instead of moving to the next alternative branch
961        at the same level (in this case, to look for "c"). The Perl documentation
962        is clear that when (*THEN) is backtracked onto, it goes to the "next
963        alternative in the innermost enclosing group".
964    
965    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
966        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
967        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
968        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
969        (*THEN).
970    
971    3.  If \s appeared in a character class, it removed the VT character from
972        the class, even if it had been included by some previous item, for example
973        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
974        of \s, but is part of the POSIX "space" class.)
975    
976    4.  A partial match never returns an empty string (because you can always
977        match an empty string at the end of the subject); however the checking for
978        an empty string was starting at the "start of match" point. This has been
979        changed to the "earliest inspected character" point, because the returned
980        data for a partial match starts at this character. This means that, for
981        example, /(?<=abc)def/ gives a partial match for the subject "abc"
982        (previously it gave "no match").
983    
984    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
985        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
986        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
987        has an implication that the given string is incomplete (because a partial
988        match is preferred over a full match). For this reason, these items now
989        give a partial match in this situation. [Aside: previously, the one case
990        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
991        match rather than a full match, which was wrong by the old rules, but is
992        now correct.]
993    
994    6.  There was a bug in the handling of #-introduced comments, recognized when
995        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
996        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
997        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
998        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
999        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1000        places in pcre_compile().
1001    
1002    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1003        comments when looking ahead for named forward references to subpatterns,
1004        the only newline sequence it recognized was NL. It now handles newlines
1005        according to the set newline convention.
1006    
1007    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1008        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1009        cater for a lack of strerror(). These oversights have been fixed.
1010    
1011    9.  Added --match-limit and --recursion-limit to pcregrep.
1012    
1013    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1014    
1015    11. When the -o option was used, pcregrep was setting a return code of 1, even
1016        when matches were found, and --line-buffered was not being honoured.
1017    
1018    12. Added an optional parentheses number to the -o and --only-matching options
1019        of pcregrep.
1020    
1021    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1022        can match an empty string. The code to do it in pcretest and pcredemo
1023        needed fixing:
1024    
1025        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1026            only one byte after an empty string match just before CRLF (this case
1027            just got forgotten; "any" and "anycrlf" were OK).
1028    
1029        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1030            mode when an empty string match preceded an ASCII character followed by
1031            a non-ASCII character. (The code for advancing by one character rather
1032            than one byte was nonsense.)
1033    
1034        (c) The pcredemo.c sample program did not have any code at all to handle
1035            the cases when CRLF is a valid newline sequence.
1036    
1037    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1038        as a starting offset was within the subject string. There is now a new
1039        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1040        negative or greater than the length of the string. In order to test this,
1041        pcretest is extended to allow the setting of negative starting offsets.
1042    
1043    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1044        starting offset points to the beginning of a UTF-8 character was
1045        unnecessarily clumsy. I tidied it up.
1046    
1047    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1048        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1049    
1050    17. Nobody had reported that the --include_dir option, which was added in
1051        release 7.7 should have been called --include-dir (hyphen, not underscore)
1052        for compatibility with GNU grep. I have changed it to --include-dir, but
1053        left --include_dir as an undocumented synonym, and the same for
1054        --exclude-dir, though that is not available in GNU grep, at least as of
1055        release 2.5.4.
1056    
1057    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1058        characters from a string of bytes) have been redefined so as not to use
1059        loops, in order to improve performance in some environments. At the same
1060        time, I abstracted some of the common code into auxiliary macros to save
1061        repetition (this should not affect the compiled code).
1062    
1063    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1064        compile-time error is now given if \c is not followed by an ASCII
1065        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1066        different, and any byte value is allowed.)
1067    
1068    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1069        START_OPTIMIZE option, which is now allowed at compile time - but just
1070        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1071        to pcregrep and other applications that have no direct access to PCRE
1072        options. The new /Y option in pcretest sets this option when calling
1073        pcre_compile().
1074    
1075    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1076        back references. Groups containing recursive back references were forced to
1077        be atomic by that change, but in the case of named groups, the amount of
1078        memory required was incorrectly computed, leading to "Failed: internal
1079        error: code overflow". This has been fixed.
1080    
1081    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1082        pcretest.c, to avoid build problems in some Borland environments.
1083    
1084    
1085    Version 8.10 25-Jun-2010
1086    ------------------------
1087    
1088    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1089        THEN.
1090    
1091    2.  (*ACCEPT) was not working when inside an atomic group.
1092    
1093    3.  Inside a character class, \B is treated as a literal by default, but
1094        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1095        causes the error). The code is unchanged, but I tidied the documentation.
1096    
1097    4.  Inside a character class, PCRE always treated \R and \X as literals,
1098        whereas Perl faults them if its -w option is set. I have changed PCRE so
1099        that it faults them when PCRE_EXTRA is set.
1100    
1101    5.  Added support for \N, which always matches any character other than
1102        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1103    
1104    6.  When compiling pcregrep with newer versions of gcc which may have
1105        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1106        declared with attribute warn_unused_result" were given. Just casting the
1107        result to (void) does not stop the warnings; a more elaborate fudge is
1108        needed. I've used a macro to implement this.
1109    
1110    7.  Minor change to pcretest.c to avoid a compiler warning.
1111    
1112    8.  Added four artifical Unicode properties to help with an option to make
1113        \s etc use properties (see next item). The new properties are: Xan
1114        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1115    
1116    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1117        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1118        this option. Modified pcretest to add /W to test this facility. Added
1119        REG_UCP to make it available via the POSIX interface.
1120    
1121    10. Added --line-buffered to pcregrep.
1122    
1123    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1124        studied, and the match started with a letter with a code point greater than
1125        127 whose first byte was different to the first byte of the other case of
1126        the letter, the other case of this starting letter was not recognized
1127        (#976).
1128    
1129    12. If a pattern that was studied started with a repeated Unicode property
1130        test, for example, \p{Nd}+, there was the theoretical possibility of
1131        setting up an incorrect bitmap of starting bytes, but fortunately it could
1132        not have actually happened in practice until change 8 above was made (it
1133        added property types that matched character-matching opcodes).
1134    
1135    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1136        possible starting bytes for non-anchored patterns.
1137    
1138    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1139        \R, and also a number of cases that involve Unicode properties, both
1140        explicit and implicit when PCRE_UCP is set.
1141    
1142    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1143        input, it could crash or give wrong results if characters with values
1144        greater than 0xc0 were present in the subject string. (Detail: it assumed
1145        UTF-8 input when processing these items.)
1146    
1147    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1148        size_t is 64-bit (#991).
1149    
1150    17. Added a check for running out of memory when PCRE is compiled with
1151        --disable-stack-for-recursion (#990).
1152    
1153    18. If the last data line in a file for pcretest does not have a newline on
1154        the end, a newline was missing in the output.
1155    
1156    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1157        less than 128) in its various bitmaps. However, there is a facility for
1158        generating tables according to the current locale when PCRE is compiled. It
1159        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1160        characters, are recognized by isspace() and therefore were getting set in
1161        these tables, and indeed these tables seem to approximate to ISO 8859. This
1162        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1163        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1164        which of course cannot start UTF-8 characters. I have changed the code so
1165        that only real ASCII characters (less than 128) and the correct starting
1166        bytes for UTF-8 encodings are set for characters greater than 127 when in
1167        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1168        altogether.)
1169    
1170    20. Added the /T option to pcretest so as to be able to run tests with non-
1171        standard character tables, thus making it possible to include the tests
1172        used for 19 above in the standard set of tests.
1173    
1174    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1175        reference to a subpattern the other side of a comment that contains an
1176        opening parenthesis caused either an internal compiling error, or a
1177        reference to the wrong subpattern.
1178    
1179    
1180    Version 8.02 19-Mar-2010
1181  ------------------------  ------------------------
1182    
1183  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.
1184    
1185  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1186      configured.      configured.
1187    
1188  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1189      original author of that file, following a query about its status.      original author of that file, following a query about its status.
1190    
1191  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1192      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1193    
1194  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1195      quantifier applied to a forward-referencing subroutine call, could compile      quantifier applied to a forward-referencing subroutine call, could compile
1196      incorrect code or give the error "internal error: previously-checked      incorrect code or give the error "internal error: previously-checked
1197      referenced subpattern not found".      referenced subpattern not found".
1198    
1199  6.  Both MS Visual Studio and Symbian OS have problems with initializing  6.  Both MS Visual Studio and Symbian OS have problems with initializing
1200      variables to point to external functions. For these systems, therefore,      variables to point to external functions. For these systems, therefore,
1201      pcre_malloc etc. are now initialized to local functions that call the      pcre_malloc etc. are now initialized to local functions that call the
1202      relevant global functions.      relevant global functions.
1203    
1204  7.  There were two entries missing in the vectors called coptable and poptable  7.  There were two entries missing in the vectors called coptable and poptable
1205      in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.      in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1206      I've fixed the data, and added a kludgy way of testing at compile time that      I've fixed the data, and added a kludgy way of testing at compile time that
1207      the lengths are correct (equal to the number of opcodes).      the lengths are correct (equal to the number of opcodes).
1208    
1209  8.  Following on from 7, I added a similar kludge to check the length of the  8.  Following on from 7, I added a similar kludge to check the length of the
1210      eint vector in pcreposix.c.      eint vector in pcreposix.c.
1211    
1212  9.  Error texts for pcre_compile() are held as one long string to avoid too  9.  Error texts for pcre_compile() are held as one long string to avoid too
1213      much relocation at load time. To find a text, the string is searched,      much relocation at load time. To find a text, the string is searched,
1214      counting zeros. There was no check for running off the end of the string,      counting zeros. There was no check for running off the end of the string,
1215      which could happen if a new error number was added without updating the      which could happen if a new error number was added without updating the
1216      string.      string.
1217    
1218  10. \K gave a compile-time error if it appeared in a lookbehind assersion.  10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1219    
1220  11. \K was not working if it appeared in an atomic group or in a group that  11. \K was not working if it appeared in an atomic group or in a group that
1221      was called as a "subroutine", or in an assertion. Perl 5.11 documents that      was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1222      \K is "not well defined" if used in an assertion. PCRE now accepts it if      \K is "not well defined" if used in an assertion. PCRE now accepts it if
1223      the assertion is positive, but not if it is negative.      the assertion is positive, but not if it is negative.
1224    
1225  12. Change 11 fortuitously reduced the size of the stack frame used in the  12. Change 11 fortuitously reduced the size of the stack frame used in the
1226      "match()" function of pcre_exec.c by one pointer. Forthcoming      "match()" function of pcre_exec.c by one pointer. Forthcoming
1227      implementation of support for (*MARK) will need an extra pointer on the      implementation of support for (*MARK) will need an extra pointer on the
1228      stack; I have reserved it now, so that the stack frame size does not      stack; I have reserved it now, so that the stack frame size does not
1229      decrease.      decrease.
1230    
1231  13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other  13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1232      item in branch that calls a recursion is a subroutine call - as in the      item in branch that calls a recursion is a subroutine call - as in the
1233      second branch in the above example - was incorrectly given the compile-      second branch in the above example - was incorrectly given the compile-
1234      time error "recursive call could loop indefinitely" because pcre_compile()      time error "recursive call could loop indefinitely" because pcre_compile()
1235      was not correctly checking the subroutine for matching a non-empty string.      was not correctly checking the subroutine for matching a non-empty string.
1236    
1237  14. The checks for overrunning compiling workspace could trigger after an  14. The checks for overrunning compiling workspace could trigger after an
1238      overrun had occurred. This is a "should never occur" error, but it can be      overrun had occurred. This is a "should never occur" error, but it can be
1239      triggered by pathological patterns such as hundreds of nested parentheses.      triggered by pathological patterns such as hundreds of nested parentheses.
1240      The checks now trigger 100 bytes before the end of the workspace.      The checks now trigger 100 bytes before the end of the workspace.
1241    
1242    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1243    
1244    
1245  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010

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