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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.10 03 May-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    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
64        offset of the starting point of the matching process, provided the offsets
65        vector is large enough.
66    
67    17. The \A escape now records a lookbehind value of 1, though its execution
68        does not actually inspect the previous character. This is to ensure that,
69        in partial multi-segment matching, at least one character from the old
70        segment is retained when a new segment is processed. Otherwise, if there
71        are no lookbehinds in the pattern, \A might match incorrectly at the start
72        of a new segment.
73    
74    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
75    
76    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
77        gives some modest performance improvement in 8-bit mode.
78    
79    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
80        be expressed in certain programming languages using Universal Character
81        Names.
82    
83    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
84        which points out that "non characters" are not "characters that may not
85        appear in Unicode strings" but rather "characters that are reserved for
86        internal use and have only local meaning".
87    
88    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
89        there was a conditional group that depended on an assertion, if the
90        assertion was false, the callout that immediately followed the alternation
91        in the condition was skipped when pcre_exec() was used for matching.
92    
93    23. Allow an explicit callout to be inserted before an assertion that is the
94        condition for a conditional group, for compatibility with automatic
95        callouts, which always insert a callout at this point.
96    
97    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
98        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
99    
100    25. (*PRUNE) is now supported by the JIT compiler.
101    
102    
103    Version 8.32 30-November-2012
104    -----------------------------
105    
106    1.  Improved JIT compiler optimizations for first character search and single
107        character iterators.
108    
109    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
110        Patch by Daniel Richard G.
111    
112    3.  Single character iterator optimizations in the JIT compiler.
113    
114    4.  Improved JIT compiler optimizations for character ranges.
115    
116    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
117        Reported by Giuseppe D'Angelo.
118    
119    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
120        of a line, was being set incorrectly in cases where .* appeared inside
121        atomic brackets at the start of a pattern, or where there was a subsequent
122        *PRUNE or *SKIP.
123    
124    7.  Improved instruction cache flush for POWER/PowerPC.
125        Patch by Daniel Richard G.
126    
127    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
128        grep:
129    
130        (a) There is now no limit to the number of patterns to be matched.
131    
132        (b) An error is given if a pattern is too long.
133    
134        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
135            are now supported.
136    
137        (d) --exclude-from and --include-from (multiple use) have been added.
138    
139        (e) Exclusions and inclusions now apply to all files and directories, not
140            just to those obtained from scanning a directory recursively.
141    
142        (f) Multiple uses of -f and --file-list are now supported.
143    
144        (g) In a Windows environment, the default for -d has been changed from
145            "read" (the GNU grep default) to "skip", because otherwise the presence
146            of a directory in the file list provokes an error.
147    
148        (h) The documentation has been revised and clarified in places.
149    
150    9.  Improve the matching speed of capturing brackets.
151    
152    10. Changed the meaning of \X so that it now matches a Unicode extended
153        grapheme cluster.
154    
155    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
156        out POSIX threads when JIT support is configured.
157    
158    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
159    
160    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
161        structure could go wrong in environments where size_t is not the same size
162        as int.
163    
164    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
165        set.
166    
167    15. The EBCDIC support had decayed; later updates to the code had included
168        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
169        general tidy up of EBCDIC-related issues, and the documentation was also
170        not quite right. There is now a test that can be run on ASCII systems to
171        check some of the EBCDIC-related things (but is it not a full test).
172    
173    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
174        in a small tidy to the code.
175    
176    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
177    
178    18. If the --only-matching (-o) option in pcregrep is specified multiple
179        times, each one causes appropriate output. For example, -o1 -o2 outputs the
180        substrings matched by the 1st and 2nd capturing parentheses. A separating
181        string can be specified by --om-separator (default empty).
182    
183    19. Improving the first n character searches.
184    
185    20. Turn case lists for horizontal and vertical white space into macros so that
186        they are defined only once.
187    
188    21. This set of changes together give more compatible Unicode case-folding
189        behaviour for characters that have more than one other case when UCP
190        support is available.
191    
192        (a) The Unicode property table now has offsets into a new table of sets of
193            three or more characters that are case-equivalent. The MultiStage2.py
194            script that generates these tables (the pcre_ucd.c file) now scans
195            CaseFolding.txt instead of UnicodeData.txt for character case
196            information.
197    
198        (b) The code for adding characters or ranges of characters to a character
199            class has been abstracted into a generalized function that also handles
200            case-independence. In UTF-mode with UCP support, this uses the new data
201            to handle characters with more than one other case.
202    
203        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
204            whose other case is greater than 256 are now correctly matched
205            caselessly. Previously, the high codepoint matched the low one, but not
206            vice versa.
207    
208        (d) The processing of \h, \H, \v, and \ in character classes now makes use
209            of the new class addition function, using character lists defined as
210            macros alongside the case definitions of 20 above.
211    
212        (e) Caseless back references now work with characters that have more than
213            one other case.
214    
215        (f) General caseless matching of characters with more than one other case
216            is supported.
217    
218    22. Unicode character properties were updated from Unicode 6.2.0
219    
220    23. Improved CMake support under Windows. Patch by Daniel Richard G.
221    
222    24. Add support for 32-bit character strings, and UTF-32
223    
224    25. Major JIT compiler update (code refactoring and bugfixing).
225        Experimental Sparc 32 support is added.
226    
227    26. Applied a modified version of Daniel Richard G's patch to create
228        pcre.h.generic and config.h.generic by "make" instead of in the
229        PrepareRelease script.
230    
231    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
232        pcre_compile.c when checking for a zero character.
233    
234    28. Introducing a native interface for JIT. Through this interface, the compiled
235        machine code can be directly executed. The purpose of this interface is to
236        provide fast pattern matching, so several sanity checks are not performed.
237        However, feature tests are still performed. The new interface provides
238        1.4x speedup compared to the old one.
239    
240    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
241        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
242        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
243    
244    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
245        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
246        the "old" RFC 2279). Instead, it ended up passing a negative length to
247        pcre_exec().
248    
249    31. Add support for GCC's visibility feature to hide internal functions.
250    
251    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
252        "unknown -C option" after outputting 0 or 1.
253    
254    33. There is now support for generating a code coverage report for the test
255        suite in environments where gcc is the compiler and lcov is installed. This
256        is mainly for the benefit of the developers.
257    
258    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
259        unaddressable using valgrind annotations, allowing valgrind to detect
260        invalid memory accesses. This is mainly for the benefit of the developers.
261    
262    25. (*UTF) can now be used to start a pattern in any of the three libraries.
263    
264    26. Give configure error if --enable-cpp but no C++ compiler found.
265    
266    
267    Version 8.31 06-July-2012
268    -------------------------
269    
270    1.  Fixing a wrong JIT test case and some compiler warnings.
271    
272    2.  Removed a bashism from the RunTest script.
273    
274    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
275        to unsigned type, result still unsigned" that was given by an MS compiler
276        on encountering the code "-sizeof(xxx)".
277    
278    4.  Partial matching support is added to the JIT compiler.
279    
280    5.  Fixed several bugs concerned with partial matching of items that consist
281        of more than one character:
282    
283        (a) /^(..)\1/ did not partially match "aba" because checking references was
284            done on an "all or nothing" basis. This also applied to repeated
285            references.
286    
287        (b) \R did not give a hard partial match if \r was found at the end of the
288            subject.
289    
290        (c) \X did not give a hard partial match after matching one or more
291            characters at the end of the subject.
292    
293        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
294            a partial match for the string "\r".
295    
296        (e) When newline was set to CRLF, the metacharacter "." did not recognize
297            a partial match for a CR character at the end of the subject string.
298    
299    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
300        running pcretest, the text "(JIT)" added to the output whenever JIT is
301        actually used to run the match.
302    
303    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
304        or /S+[+] with a digit between 1 and 7.
305    
306    8.  OP_NOT now supports any UTF character not just single-byte ones.
307    
308    9.  (*MARK) control verb is now supported by the JIT compiler.
309    
310    10. The command "./RunTest list" lists the available tests without actually
311        running any of them. (Because I keep forgetting what they all are.)
312    
313    11. Add PCRE_INFO_MAXLOOKBEHIND.
314    
315    12. Applied a (slightly modified) user-supplied patch that improves performance
316        when the heap is used for recursion (compiled with --disable-stack-for-
317        recursion). Instead of malloc and free for each heap frame each time a
318        logical recursion happens, frames are retained on a chain and re-used where
319        possible. This sometimes gives as much as 30% improvement.
320    
321    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
322        call.
323    
324    14. As documented, (*COMMIT) is now confined to within a positive assertion.
325    
326    15. It is now possible to link pcretest with libedit as an alternative to
327        libreadline.
328    
329    16. (*COMMIT) control verb is now supported by the JIT compiler.
330    
331    17. The Unicode data tables have been updated to Unicode 6.1.0.
332    
333    18. Added --file-list option to pcregrep.
334    
335    19. Added binary file support to pcregrep, including the -a, --binary-files,
336        -I, and --text options.
337    
338    20. The madvise function is renamed for posix_madvise for QNX compatibility
339        reasons. Fixed by Giuseppe D'Angelo.
340    
341    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
342    
343    22. Changed the option for creating symbolic links for 16-bit man pages from
344        -s to -sf so that re-installing does not cause issues.
345    
346    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
347    
348    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
349        matches in certain environments (the workspace was not being correctly
350        retained). Also added to pcre_dfa_exec() a simple plausibility check on
351        some of the workspace data at the beginning of a restart.
352    
353    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
354        was not doing so when it should - probably a typo introduced by SVN 528
355        (change 8.10/14).
356    
357    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
358        \w+ when the character tables indicated that \x{c4} was a word character.
359        There were several related cases, all because the tests for doing a table
360        lookup were testing for characters less than 127 instead of 255.
361    
362    27. If a pattern contains capturing parentheses that are not used in a match,
363        their slots in the ovector are set to -1. For those that are higher than
364        any matched groups, this happens at the end of processing. In the case when
365        there were back references that the ovector was too small to contain
366        (causing temporary malloc'd memory to be used during matching), and the
367        highest capturing number was not used, memory off the end of the ovector
368        was incorrectly being set to -1. (It was using the size of the temporary
369        memory instead of the true size.)
370    
371    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
372        ovector size, it uses memory at the end of the block that it has got.
373    
374    29. Check for an overlong MARK name and give an error at compile time. The
375        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
376    
377    30. JIT compiler update.
378    
379    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
380        Rill for the patch.
381    
382    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
383    
384    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
385    
386    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
387        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
388        was enabled.
389    
390    35. Improve JIT code generation for greedy plus quantifier.
391    
392    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
393        1 to "aa" instead of to an empty string. The bug affected repeated groups
394        that could potentially match an empty string.
395    
396    37. Optimizing single character iterators in JIT.
397    
398    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
399        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
400        codepoints that are too big for the mode are faulted, and in a UTF mode,
401        disallowed codepoints are also faulted.
402    
403    39. If PCRE was compiled with UTF support, in three places in the DFA
404        matcher there was code that should only have been obeyed in UTF mode, but
405        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
406        processing when bytes with values greater than 127 were present. In 16-bit
407        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
408        both cases the values are those that cannot be the first data item in a UTF
409        character. The three items that might have provoked this were recursions,
410        possessively repeated groups, and atomic groups.
411    
412    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
413        and pcregrep, because some OS require shared objects to be explicitly
414        passed to ld, causing the link step to fail if they are not.
415    
416    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
417        mode, patterns that started with \h* or \R* might be incorrectly matched.
418    
419    
420    Version 8.30 04-February-2012
421    -----------------------------
422    
423    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
424        name is defined in ctype.h.
425    
426    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
427        only in quite long subpatterns.
428    
429    3.  Removed the function pcre_info(), which has been obsolete and deprecated
430        since it was replaced by pcre_fullinfo() in February 2000.
431    
432    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
433        match a (*MARK), and the match failed at the start of the subject, a
434        reference to memory before the start of the subject could occur. This bug
435        was introduced by fix 17 of release 8.21.
436    
437    5.  A reference to an unset group with zero minimum repetition was giving
438        totally wrong answers (in non-JavaScript-compatibility mode). For example,
439        /(another)?(\1?)test/ matched against "hello world test". This bug was
440        introduced in release 8.13.
441    
442    6.  Add support for 16-bit character strings (a large amount of work involving
443        many changes and refactorings).
444    
445    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
446        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
447        from a file.
448    
449    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
450        rounding is not applied in this particular case).
451    
452    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
453        if they appear, or are escaped, in patterns.
454    
455    10. Get rid of a number of -Wunused-but-set-variable warnings.
456    
457    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
458        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
459        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
460        also returns the mark "x". This bug applied to capturing parentheses,
461        non-capturing parentheses, and atomic parentheses. It also applied to some
462        assertions.
463    
464    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
465        information out of configure.ac instead of relying on pcre.h.generic, which
466        is not stored in the repository.
467    
468    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
469        -lreadline.
470    
471    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
472    
473    15. Applied Graycode's patch to put the top-level frame on the stack rather
474        than the heap when not using the stack for recursion. This gives a
475        performance improvement in many cases when recursion is not deep.
476    
477    16. Experimental code added to "pcretest -C" to output the stack frame size.
478    
479    
480    Version 8.21 12-Dec-2011
481    ------------------------
482    
483    1.  Updating the JIT compiler.
484    
485    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
486        are added as well.
487    
488    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
489        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
490        calling _pcre_jit_exec. Some extra comments are added.
491    
492    4.  (*MARK) settings inside atomic groups that do not contain any capturing
493        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
494        was introduced by change 18 for 8.20.
495    
496    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
497        ECMA-262 standard.
498    
499    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
500        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
501        This bug was probably introduced by change 9 of 8.13.
502    
503    7.  While fixing 6 above, I noticed that a number of other items were being
504        incorrectly rejected as "not fixed length". This arose partly because newer
505        opcodes had not been added to the fixed-length checking code. I have (a)
506        corrected the bug and added tests for these items, and (b) arranged for an
507        error to occur if an unknown opcode is encountered while checking for fixed
508        length instead of just assuming "not fixed length". The items that were
509        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
510        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
511        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
512    
513    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
514        being incorrectly compiled and would have given unpredicatble results.
515    
516    9.  A possessively repeated subpattern with minimum repeat count greater than
517        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
518        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
519        the first (A) could occur when it should not.
520    
521    10. Add a cast and remove a redundant test from the code.
522    
523    11. JIT should use pcre_malloc/pcre_free for allocation.
524    
525    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
526        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
527        is anything other than /usr, -L is still shown).
528    
529    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
530    
531    14. Perl does not support \N without a following name in a [] class; PCRE now
532        also gives an error.
533    
534    15. If a forward reference was repeated with an upper limit of around 2000,
535        it caused the error "internal error: overran compiling workspace". The
536        maximum number of forward references (including repeats) was limited by the
537        internal workspace, and dependent on the LINK_SIZE. The code has been
538        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
539        the default depends on LINK_SIZE. There is a new upper limit (for safety)
540        of around 200,000 forward references. While doing this, I also speeded up
541        the filling in of repeated forward references.
542    
543    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
544        incorrectly expecting the subject to contain another "a" after the start.
545    
546    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
547        in the match, the SKIP should be ignored. This was not happening; instead
548        the SKIP was being treated as NOMATCH. For patterns such as
549        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
550        tested.
551    
552    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
553        now much more compatible with Perl, in particular in cases where the result
554        is a non-match for a non-anchored pattern. For example, if
555        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
556        "m", where previously it did not return a name. A side effect of this
557        change is that for partial matches, the last encountered mark name is
558        returned, as for non matches. A number of tests that were previously not
559        Perl-compatible have been moved into the Perl-compatible test files. The
560        refactoring has had the pleasing side effect of removing one argument from
561        the match() function, thus reducing its stack requirements.
562    
563    19. If the /S+ option was used in pcretest to study a pattern using JIT,
564        subsequent uses of /S (without +) incorrectly behaved like /S+.
565    
566    21. Retrieve executable code size support for the JIT compiler and fixing
567        some warnings.
568    
569    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
570        not work when the shorter character appeared right at the end of the
571        subject string.
572    
573    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
574        systems.
575    
576    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
577        output it when the /M option is used in pcretest.
578    
579    25. The CheckMan script was not being included in the distribution. Also, added
580        an explicit "perl" to run Perl scripts from the PrepareRelease script
581        because this is reportedly needed in Windows.
582    
583    26. If study data was being save in a file and studying had not found a set of
584        "starts with" bytes for the pattern, the data written to the file (though
585        never used) was taken from uninitialized memory and so caused valgrind to
586        complain.
587    
588    27. Updated RunTest.bat as provided by Sheri Pierce.
589    
590    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
591    
592    29. Computation of memory usage for the table of capturing group names was
593        giving an unnecessarily large value.
594    
595    
596    Version 8.20 21-Oct-2011
597    ------------------------
598    
599    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
600        a POSIX class. After further experiments with Perl, which convinced me that
601        Perl has bugs and confusions, a closing square bracket is no longer allowed
602        in a POSIX name. This bug also affected patterns with classes that started
603        with full stops.
604    
605    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
606        captured substring, but while checking the failing first alternative,
607        substring 1 is temporarily captured. If the output vector supplied to
608        pcre_exec() was not big enough for this capture, the yield of the function
609        was still zero ("insufficient space for captured substrings"). This cannot
610        be totally fixed without adding another stack variable, which seems a lot
611        of expense for a edge case. However, I have improved the situation in cases
612        such as /(a)(b)x|abc/ matched against "abc", where the return code
613        indicates that fewer than the maximum number of slots in the ovector have
614        been set.
615    
616    3.  Related to (2) above: when there are more back references in a pattern than
617        slots in the output vector, pcre_exec() uses temporary memory during
618        matching, and copies in the captures as far as possible afterwards. It was
619        using the entire output vector, but this conflicts with the specification
620        that only 2/3 is used for passing back captured substrings. Now it uses
621        only the first 2/3, for compatibility. This is, of course, another edge
622        case.
623    
624    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
625        main code base, and can be used by building with --enable-jit. When this is
626        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
627        runtime --no-jit option is given.
628    
629    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
630        ovector, the return from the function was zero, implying that there were
631        other matches that did not fit. The correct "exactly full" value is now
632        returned.
633    
634    6.  If a subpattern that was called recursively or as a subroutine contained
635        (*PRUNE) or any other control that caused it to give a non-standard return,
636        invalid errors such as "Error -26 (nested recursion at the same subject
637        position)" or even infinite loops could occur.
638    
639    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
640        computing the minimum length on reaching *ACCEPT, and so ended up with the
641        wrong value of 1 rather than 0. Further investigation indicates that
642        computing a minimum subject length in the presence of *ACCEPT is difficult
643        (think back references, subroutine calls), and so I have changed the code
644        so that no minimum is registered for a pattern that contains *ACCEPT.
645    
646    8.  If (*THEN) was present in the first (true) branch of a conditional group,
647        it was not handled as intended. [But see 16 below.]
648    
649    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
650        Sheri Pierce.
651    
652    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
653        the first byte in a match must be "a".
654    
655    11. Change 17 for 8.13 increased the recursion depth for patterns like
656        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
657        pattern contains any instances of (*THEN). If it does not, the old
658        optimizations are restored. It would be nice to do this on a per-group
659        basis, but at the moment that is not feasible.
660    
661    12. In some environments, the output of pcretest -C is CRLF terminated. This
662        broke RunTest's code that checks for the link size. A single white space
663        character after the value is now allowed for.
664    
665    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
666        For "fr", it uses the Windows-specific input and output files.
667    
668    14. If (*THEN) appeared in a group that was called recursively or as a
669        subroutine, it did not work as intended. [But see next item.]
670    
671    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
672        pattern fragments (but not containing any | characters). If A and B are
673        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
674        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
675        D. In other words, Perl considers parentheses that do not contain any |
676        characters to be part of a surrounding alternative, whereas PCRE was
677        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
678        differently. PCRE now behaves in the same way as Perl, except in the case
679        of subroutine/recursion calls such as (?1) which have in any case always
680        been different (but PCRE had them first :-).
681    
682    16. Related to 15 above: Perl does not treat the | in a conditional group as
683        creating alternatives. Such a group is treated in the same way as an
684        ordinary group without any | characters when processing (*THEN). PCRE has
685        been changed to match Perl's behaviour.
686    
687    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
688        RunGrepTest script failed.
689    
690    18. Change 22 for version 13 caused atomic groups to use more stack. This is
691        inevitable for groups that contain captures, but it can lead to a lot of
692        stack use in large patterns. The old behaviour has been restored for atomic
693        groups that do not contain any capturing parentheses.
694    
695    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
696        suppress the check for a minimum subject length at run time. (If it was
697        given to pcre_exec() or pcre_dfa_exec() it did work.)
698    
699    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
700        fail to work when decoding hex characters in data strings in EBCDIC
701        environments.
702    
703    21. It appears that in at least one Mac OS environment, the isxdigit() function
704        is implemented as a macro that evaluates to its argument more than once,
705        contravening the C 90 Standard (I haven't checked a later standard). There
706        was an instance in pcretest which caused it to go wrong when processing
707        \x{...} escapes in subject strings. The has been rewritten to avoid using
708        things like p++ in the argument of isxdigit().
709    
710    
711    Version 8.13 16-Aug-2011
712    ------------------------
713    
714    1.  The Unicode data tables have been updated to Unicode 6.0.0.
715    
716    2.  Two minor typos in pcre_internal.h have been fixed.
717    
718    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
719        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
720        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
721    
722    4.  There were a number of related bugs in the code for matching backrefences
723        caselessly in UTF-8 mode when codes for the characters concerned were
724        different numbers of bytes. For example, U+023A and U+2C65 are an upper
725        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
726        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
727        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
728        2-byte code at the end of the subject (it thought there wasn't enough data
729        left).
730    
731    5.  Comprehensive information about what went wrong is now returned by
732        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
733        as the output vector has at least 2 elements. The offset of the start of
734        the failing character and a reason code are placed in the vector.
735    
736    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
737        now returned is for the first byte of the failing character, instead of the
738        last byte inspected. This is an incompatible change, but I hope it is small
739        enough not to be a problem. It makes the returned offset consistent with
740        pcre_exec() and pcre_dfa_exec().
741    
742    7.  pcretest now gives a text phrase as well as the error number when
743        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
744        failure, the offset and reason code are output.
745    
746    8.  When \R was used with a maximizing quantifier it failed to skip backwards
747        over a \r\n pair if the subsequent match failed. Instead, it just skipped
748        back over a single character (\n). This seems wrong (because it treated the
749        two characters as a single entity when going forwards), conflicts with the
750        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
751        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
752        has been changed.
753    
754    9.  Some internal refactoring has changed the processing so that the handling
755        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
756        time (the PCRE_DOTALL option was changed this way some time ago: version
757        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
758        which was always a bit of a fudge. It also means that there is one less
759        argument for the match() function, which reduces its stack requirements
760        slightly. This change also fixes an incompatibility with Perl: the pattern
761        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
762    
763    10. More internal refactoring has drastically reduced the number of recursive
764        calls to match() for possessively repeated groups such as (abc)++ when
765        using pcre_exec().
766    
767    11. While implementing 10, a number of bugs in the handling of groups were
768        discovered and fixed:
769    
770        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
771        (a|)*(?1) gave a compile-time internal error.
772        ((a|)+)+  did not notice that the outer group could match an empty string.
773        (^a|^)+   was not marked as anchored.
774        (.*a|.*)+ was not marked as matching at start or after a newline.
775    
776    12. Yet more internal refactoring has removed another argument from the match()
777        function. Special calls to this function are now indicated by setting a
778        value in a variable in the "match data" data block.
779    
780    13. Be more explicit in pcre_study() instead of relying on "default" for
781        opcodes that mean there is no starting character; this means that when new
782        ones are added and accidentally left out of pcre_study(), testing should
783        pick them up.
784    
785    14. The -s option of pcretest has been documented for ages as being an old
786        synonym of -m (show memory usage). I have changed it to mean "force study
787        for every regex", that is, assume /S for every regex. This is similar to -i
788        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
789        using it. It makes it easier to run collections of tests with and without
790        study enabled, and thereby test pcre_study() more easily. All the standard
791        tests are now run with and without -s (but some patterns can be marked as
792        "never study" - see 20 below).
793    
794    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
795        restoration of the capturing data to the outer values was not happening
796        correctly.
797    
798    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
799        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
800        pattern had matched an empty string, and so incorrectly returned a no
801        match.
802    
803    17. There was optimizing code for the last branch of non-capturing parentheses,
804        and also for the obeyed branch of a conditional subexpression, which used
805        tail recursion to cut down on stack usage. Unfortunately, now that there is
806        the possibility of (*THEN) occurring in these branches, tail recursion is
807        no longer possible because the return has to be checked for (*THEN). These
808        two optimizations have therefore been removed. [But see 8.20/11 above.]
809    
810    18. If a pattern containing \R was studied, it was assumed that \R always
811        matched two bytes, thus causing the minimum subject length to be
812        incorrectly computed because \R can also match just one byte.
813    
814    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
815        was incorrectly computed.
816    
817    20. If /S is present twice on a test pattern in pcretest input, it now
818        *disables* studying, thereby overriding the use of -s on the command line
819        (see 14 above). This is necessary for one or two tests to keep the output
820        identical in both cases.
821    
822    21. When (*ACCEPT) was used in an assertion that matched an empty string and
823        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
824    
825    22. When an atomic group that contained a capturing parenthesis was
826        successfully matched, but the branch in which it appeared failed, the
827        capturing was not being forgotten if a higher numbered group was later
828        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
829        group 1 to "a", when in fact it should be unset. This applied to multi-
830        branched capturing and non-capturing groups, repeated or not, and also to
831        positive assertions (capturing in negative assertions does not happen
832        in PCRE) and also to nested atomic groups.
833    
834    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
835        subject after a captured substring, to make it easier to tell which of a
836        number of identical substrings has been captured.
837    
838    24. The way atomic groups are processed by pcre_exec() has been changed so that
839        if they are repeated, backtracking one repetition now resets captured
840        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
841        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
842        "aaa". Previously, it would have been "a". As part of this code
843        refactoring, the way recursive calls are handled has also been changed.
844    
845    25. If an assertion condition captured any substrings, they were not passed
846        back unless some other capturing happened later. For example, if
847        (?(?=(a))a) was matched against "a", no capturing was returned.
848    
849    26. When studying a pattern that contained subroutine calls or assertions,
850        the code for finding the minimum length of a possible match was handling
851        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
852        group 1 called group 2 while simultaneously a separate group 2 called group
853        1). A stack overflow occurred in this case. I have fixed this by limiting
854        the recursion depth to 10.
855    
856    27. Updated RunTest.bat in the distribution to the version supplied by Tom
857        Fortmann. This supports explicit test numbers on the command line, and has
858        argument validation and error reporting.
859    
860    28. An instance of \X with an unlimited repeat could fail if at any point the
861        first character it looked at was a mark character.
862    
863    29. Some minor code refactoring concerning Unicode properties and scripts
864        should reduce the stack requirement of match() slightly.
865    
866    30. Added the '=' option to pcretest to check the setting of unused capturing
867        slots at the end of the pattern, which are documented as being -1, but are
868        not included in the return count.
869    
870    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
871        compiled something random. Now it gives a compile-time error (as does
872        Perl).
873    
874    32. A *MARK encountered during the processing of a positive assertion is now
875        recorded and passed back (compatible with Perl).
876    
877    33. If --only-matching or --colour was set on a pcregrep call whose pattern
878        had alternative anchored branches, the search for a second match in a line
879        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
880        matched the line "0102" twice. The same bug affected patterns that started
881        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
882        twice.
883    
884    34. Previously, PCRE did not allow quantification of assertions. However, Perl
885        does, and because of capturing effects, quantifying parenthesized
886        assertions may at times be useful. Quantifiers are now allowed for
887        parenthesized assertions.
888    
889    35. A minor code tidy in pcre_compile() when checking options for \R usage.
890    
891    36. \g was being checked for fancy things in a character class, when it should
892        just be a literal "g".
893    
894    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
895        appearance of a nested POSIX class supersedes an apparent external class.
896        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
897        unescaped square brackets may also appear as part of class names. For
898        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
899        more like Perl. (But see 8.20/1 above.)
900    
901    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
902        was because it thought it was \N{name}, which is not supported).
903    
904    39. Add minix to OS list not supporting the -S option in pcretest.
905    
906    40. PCRE tries to detect cases of infinite recursion at compile time, but it
907        cannot analyze patterns in sufficient detail to catch mutual recursions
908        such as ((?1))((?2)). There is now a runtime test that gives an error if a
909        subgroup is called recursively as a subpattern for a second time at the
910        same position in the subject string. In previous releases this might have
911        been caught by the recursion limit, or it might have run out of stack.
912    
913    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
914        happen only once. PCRE was, however incorrectly giving a compile time error
915        "recursive call could loop indefinitely" because it cannot analyze the
916        pattern in sufficient detail. The compile time test no longer happens when
917        PCRE is compiling a conditional subpattern, but actual runaway loops are
918        now caught at runtime (see 40 above).
919    
920    42. It seems that Perl allows any characters other than a closing parenthesis
921        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
922        has been changed to be the same.
923    
924    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
925        as not to get warnings when autogen.sh is called. Also changed
926        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
927    
928    44. To help people who use pcregrep to scan files containing exceedingly long
929        lines, the following changes have been made:
930    
931        (a) The default value of the buffer size parameter has been increased from
932            8K to 20K. (The actual buffer used is three times this size.)
933    
934        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
935            PCRE is built.
936    
937        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
938            to be set at run time.
939    
940        (d) Numerical values in pcregrep options can be followed by K or M, for
941            example --buffer-size=50K.
942    
943        (e) If a line being scanned overflows pcregrep's buffer, an error is now
944            given and the return code is set to 2.
945    
946    45. Add a pointer to the latest mark to the callout data block.
947    
948    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
949        partial match of an empty string instead of no match. This was specific to
950        the use of ".".
951    
952    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
953        complete match instead of a partial match. This bug was dependent on both
954        the PCRE_UTF8 and PCRE_DOTALL options being set.
955    
956    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
957        starting byte set, because \b was not being ignored.
958    
959    
960    Version 8.12 15-Jan-2011
961    ------------------------
962    
963    1.  Fixed some typos in the markup of the man pages, and wrote a script that
964        checks for such things as part of the documentation building process.
965    
966    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
967        --match-limit and --recursion-limit options (added for 8.11). In
968        particular, this made one of the standard tests fail. (The integer value
969        went into the wrong half of a long int.)
970    
971    3.  If the --colour option was given to pcregrep with -v (invert match), it
972        did strange things, either producing crazy output, or crashing. It should,
973        of course, ignore a request for colour when reporting lines that do not
974        match.
975    
976    4.  Another pcregrep bug caused similar problems if --colour was specified with
977        -M (multiline) and the pattern match finished with a line ending.
978    
979    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
980        matched in multiline mode, the following line was shown as part of the
981        match. This seems wrong, so I have changed it.
982    
983    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
984        the check for further matches in the same line (so they could be coloured)
985        to overrun the end of the current line. If another match was found, it was
986        incorrectly shown (and then shown again when found in the next line).
987    
988    7.  If pcregrep was compiled under Windows, there was a reference to the
989        function pcregrep_exit() before it was defined. I am assuming this was
990        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
991        reported by a user. I've moved the definition above the reference.
992    
993    
994    Version 8.11 10-Dec-2010
995    ------------------------
996    
997    1.  (*THEN) was not working properly if there were untried alternatives prior
998        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
999        backtracked to try for "b" instead of moving to the next alternative branch
1000        at the same level (in this case, to look for "c"). The Perl documentation
1001        is clear that when (*THEN) is backtracked onto, it goes to the "next
1002        alternative in the innermost enclosing group".
1003    
1004    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1005        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1006        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1007        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1008        (*THEN).
1009    
1010    3.  If \s appeared in a character class, it removed the VT character from
1011        the class, even if it had been included by some previous item, for example
1012        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1013        of \s, but is part of the POSIX "space" class.)
1014    
1015    4.  A partial match never returns an empty string (because you can always
1016        match an empty string at the end of the subject); however the checking for
1017        an empty string was starting at the "start of match" point. This has been
1018        changed to the "earliest inspected character" point, because the returned
1019        data for a partial match starts at this character. This means that, for
1020        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1021        (previously it gave "no match").
1022    
1023    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1024        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1025        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1026        has an implication that the given string is incomplete (because a partial
1027        match is preferred over a full match). For this reason, these items now
1028        give a partial match in this situation. [Aside: previously, the one case
1029        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1030        match rather than a full match, which was wrong by the old rules, but is
1031        now correct.]
1032    
1033    6.  There was a bug in the handling of #-introduced comments, recognized when
1034        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1035        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1036        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1037        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1038        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1039        places in pcre_compile().
1040    
1041    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1042        comments when looking ahead for named forward references to subpatterns,
1043        the only newline sequence it recognized was NL. It now handles newlines
1044        according to the set newline convention.
1045    
1046    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1047        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1048        cater for a lack of strerror(). These oversights have been fixed.
1049    
1050    9.  Added --match-limit and --recursion-limit to pcregrep.
1051    
1052    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1053    
1054    11. When the -o option was used, pcregrep was setting a return code of 1, even
1055        when matches were found, and --line-buffered was not being honoured.
1056    
1057    12. Added an optional parentheses number to the -o and --only-matching options
1058        of pcregrep.
1059    
1060    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1061        can match an empty string. The code to do it in pcretest and pcredemo
1062        needed fixing:
1063    
1064        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1065            only one byte after an empty string match just before CRLF (this case
1066            just got forgotten; "any" and "anycrlf" were OK).
1067    
1068        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1069            mode when an empty string match preceded an ASCII character followed by
1070            a non-ASCII character. (The code for advancing by one character rather
1071            than one byte was nonsense.)
1072    
1073        (c) The pcredemo.c sample program did not have any code at all to handle
1074            the cases when CRLF is a valid newline sequence.
1075    
1076    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1077        as a starting offset was within the subject string. There is now a new
1078        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1079        negative or greater than the length of the string. In order to test this,
1080        pcretest is extended to allow the setting of negative starting offsets.
1081    
1082    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1083        starting offset points to the beginning of a UTF-8 character was
1084        unnecessarily clumsy. I tidied it up.
1085    
1086    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1087        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1088    
1089    17. Nobody had reported that the --include_dir option, which was added in
1090        release 7.7 should have been called --include-dir (hyphen, not underscore)
1091        for compatibility with GNU grep. I have changed it to --include-dir, but
1092        left --include_dir as an undocumented synonym, and the same for
1093        --exclude-dir, though that is not available in GNU grep, at least as of
1094        release 2.5.4.
1095    
1096    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1097        characters from a string of bytes) have been redefined so as not to use
1098        loops, in order to improve performance in some environments. At the same
1099        time, I abstracted some of the common code into auxiliary macros to save
1100        repetition (this should not affect the compiled code).
1101    
1102    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1103        compile-time error is now given if \c is not followed by an ASCII
1104        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1105        different, and any byte value is allowed.)
1106    
1107    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1108        START_OPTIMIZE option, which is now allowed at compile time - but just
1109        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1110        to pcregrep and other applications that have no direct access to PCRE
1111        options. The new /Y option in pcretest sets this option when calling
1112        pcre_compile().
1113    
1114    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1115        back references. Groups containing recursive back references were forced to
1116        be atomic by that change, but in the case of named groups, the amount of
1117        memory required was incorrectly computed, leading to "Failed: internal
1118        error: code overflow". This has been fixed.
1119    
1120    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1121        pcretest.c, to avoid build problems in some Borland environments.
1122    
1123    
1124    Version 8.10 25-Jun-2010
1125  ------------------------  ------------------------
1126    
1127  1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and  1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
# Line 9  Version 8.10 03 May-2010 Line 1129  Version 8.10 03 May-2010
1129    
1130  2.  (*ACCEPT) was not working when inside an atomic group.  2.  (*ACCEPT) was not working when inside an atomic group.
1131    
1132  3.  Inside a character class, \B is treated as a literal by default, but  3.  Inside a character class, \B is treated as a literal by default, but
1133      faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option      faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1134      causes the error). The code is unchanged, but I tidied the documentation.      causes the error). The code is unchanged, but I tidied the documentation.
1135    
1136  4.  Inside a character class, PCRE always treated \R and \X as literals,  4.  Inside a character class, PCRE always treated \R and \X as literals,
1137      whereas Perl faults them if its -w option is set. I have changed PCRE so      whereas Perl faults them if its -w option is set. I have changed PCRE so
1138      that it faults them when PCRE_EXTRA is set.      that it faults them when PCRE_EXTRA is set.
1139    
1140  5.  Added support for \N, which always matches any character other than  5.  Added support for \N, which always matches any character other than
1141      newline. (It is the same as "." when PCRE_DOTALL is not set.)      newline. (It is the same as "." when PCRE_DOTALL is not set.)
1142    
1143  6.  When compiling pcregrep with newer versions of gcc which may have  6.  When compiling pcregrep with newer versions of gcc which may have
1144      FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',      FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1145      declared with attribute warn_unused_result" were given. Just casting the      declared with attribute warn_unused_result" were given. Just casting the
1146      result to (void) does not stop the warnings; a more elaborate fudge is      result to (void) does not stop the warnings; a more elaborate fudge is
1147      needed. I've used a macro to implement this.      needed. I've used a macro to implement this.
1148    
1149    7.  Minor change to pcretest.c to avoid a compiler warning.
1150    
1151    8.  Added four artifical Unicode properties to help with an option to make
1152        \s etc use properties (see next item). The new properties are: Xan
1153        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1154    
1155    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1156        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1157        this option. Modified pcretest to add /W to test this facility. Added
1158        REG_UCP to make it available via the POSIX interface.
1159    
1160    10. Added --line-buffered to pcregrep.
1161    
1162    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1163        studied, and the match started with a letter with a code point greater than
1164        127 whose first byte was different to the first byte of the other case of
1165        the letter, the other case of this starting letter was not recognized
1166        (#976).
1167    
1168    12. If a pattern that was studied started with a repeated Unicode property
1169        test, for example, \p{Nd}+, there was the theoretical possibility of
1170        setting up an incorrect bitmap of starting bytes, but fortunately it could
1171        not have actually happened in practice until change 8 above was made (it
1172        added property types that matched character-matching opcodes).
1173    
1174    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1175        possible starting bytes for non-anchored patterns.
1176    
1177    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1178        \R, and also a number of cases that involve Unicode properties, both
1179        explicit and implicit when PCRE_UCP is set.
1180    
1181    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1182        input, it could crash or give wrong results if characters with values
1183        greater than 0xc0 were present in the subject string. (Detail: it assumed
1184        UTF-8 input when processing these items.)
1185    
1186    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1187        size_t is 64-bit (#991).
1188    
1189    17. Added a check for running out of memory when PCRE is compiled with
1190        --disable-stack-for-recursion (#990).
1191    
1192    18. If the last data line in a file for pcretest does not have a newline on
1193        the end, a newline was missing in the output.
1194    
1195    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1196        less than 128) in its various bitmaps. However, there is a facility for
1197        generating tables according to the current locale when PCRE is compiled. It
1198        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1199        characters, are recognized by isspace() and therefore were getting set in
1200        these tables, and indeed these tables seem to approximate to ISO 8859. This
1201        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1202        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1203        which of course cannot start UTF-8 characters. I have changed the code so
1204        that only real ASCII characters (less than 128) and the correct starting
1205        bytes for UTF-8 encodings are set for characters greater than 127 when in
1206        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1207        altogether.)
1208    
1209    20. Added the /T option to pcretest so as to be able to run tests with non-
1210        standard character tables, thus making it possible to include the tests
1211        used for 19 above in the standard set of tests.
1212    
1213    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1214        reference to a subpattern the other side of a comment that contains an
1215        opening parenthesis caused either an internal compiling error, or a
1216        reference to the wrong subpattern.
1217    
1218    
1219  Version 8.02 19-Mar-2010  Version 8.02 19-Mar-2010

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