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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    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
64        offset of the starting point of the matching process, provided the offsets
65        vector is large enough.
66    
67    17. The \A escape now records a lookbehind value of 1, though its execution
68        does not actually inspect the previous character. This is to ensure that,
69        in partial multi-segment matching, at least one character from the old
70        segment is retained when a new segment is processed. Otherwise, if there
71        are no lookbehinds in the pattern, \A might match incorrectly at the start
72        of a new segment.
73    
74    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
75    
76    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
77        gives some modest performance improvement in 8-bit mode.
78    
79    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
80        be expressed in certain programming languages using Universal Character
81        Names.
82    
83    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
84        which points out that "non characters" are not "characters that may not
85        appear in Unicode strings" but rather "characters that are reserved for
86        internal use and have only local meaning".
87    
88    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
89        there was a conditional group that depended on an assertion, if the
90        assertion was false, the callout that immediately followed the alternation
91        in the condition was skipped when pcre_exec() was used for matching.
92    
93    23. Allow an explicit callout to be inserted before an assertion that is the
94        condition for a conditional group, for compatibility with automatic
95        callouts, which always insert a callout at this point.
96    
97    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
98        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
99    
100    25. (*PRUNE) is now supported by the JIT compiler.
101    
102    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
103    
104    27. Fix the case where there are two or more SKIPs with arguments that may be
105        ignored.
106    
107    28. (*SKIP) is now supported by the JIT compiler.
108    
109    29. (*THEN) is now supported by the JIT compiler.
110    
111    30. Update RunTest with additional test selector options.
112    
113    31. The way PCRE handles backtracking verbs has been changed in two ways.
114    
115        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
116        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
117        backtracking. In some cases this makes it more Perl-compatible, but Perl's
118        rather obscure rules do not always do the same thing.
119    
120        (2) Previously, backtracking verbs were confined within assertions. This is
121        no longer the case for positive assertions, except for (*ACCEPT). Again,
122        this sometimes improves Perl compatibility, and sometimes does not.
123    
124    32. A number of tests that were in test 2 because Perl did things differently
125        have been moved to test 1, because either Perl or PCRE has changed, and
126        these tests are now compatible.
127    
128    32. Control verbs are handled in the same way in JIT and interpreter.
129    
130    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
131        contained a forward subroutine reference caused a compile error.
132    
133    34. Auto-detect and optimize limited repetitions in JIT.
134    
135    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
136        blocking (*UTF) etc.
137    
138    36. In the interpreter, maximizing pattern repetitions for characters and
139        character types now use tail recursion, which reduces stack usage.
140    
141    37. The value of the max lookbehind was not correctly preserved if a compiled
142        and saved regex was reloaded on a host of different endianness.
143    
144    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION).
145    
146    
147    Version 8.32 30-November-2012
148    -----------------------------
149    
150    1.  Improved JIT compiler optimizations for first character search and single
151        character iterators.
152    
153    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
154        Patch by Daniel Richard G.
155    
156    3.  Single character iterator optimizations in the JIT compiler.
157    
158    4.  Improved JIT compiler optimizations for character ranges.
159    
160    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
161        Reported by Giuseppe D'Angelo.
162    
163    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
164        of a line, was being set incorrectly in cases where .* appeared inside
165        atomic brackets at the start of a pattern, or where there was a subsequent
166        *PRUNE or *SKIP.
167    
168    7.  Improved instruction cache flush for POWER/PowerPC.
169        Patch by Daniel Richard G.
170    
171    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
172        grep:
173    
174        (a) There is now no limit to the number of patterns to be matched.
175    
176        (b) An error is given if a pattern is too long.
177    
178        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
179            are now supported.
180    
181        (d) --exclude-from and --include-from (multiple use) have been added.
182    
183        (e) Exclusions and inclusions now apply to all files and directories, not
184            just to those obtained from scanning a directory recursively.
185    
186        (f) Multiple uses of -f and --file-list are now supported.
187    
188        (g) In a Windows environment, the default for -d has been changed from
189            "read" (the GNU grep default) to "skip", because otherwise the presence
190            of a directory in the file list provokes an error.
191    
192        (h) The documentation has been revised and clarified in places.
193    
194    9.  Improve the matching speed of capturing brackets.
195    
196    10. Changed the meaning of \X so that it now matches a Unicode extended
197        grapheme cluster.
198    
199    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
200        out POSIX threads when JIT support is configured.
201    
202    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
203    
204    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
205        structure could go wrong in environments where size_t is not the same size
206        as int.
207    
208    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
209        set.
210    
211    15. The EBCDIC support had decayed; later updates to the code had included
212        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
213        general tidy up of EBCDIC-related issues, and the documentation was also
214        not quite right. There is now a test that can be run on ASCII systems to
215        check some of the EBCDIC-related things (but is it not a full test).
216    
217    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
218        in a small tidy to the code.
219    
220    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
221    
222    18. If the --only-matching (-o) option in pcregrep is specified multiple
223        times, each one causes appropriate output. For example, -o1 -o2 outputs the
224        substrings matched by the 1st and 2nd capturing parentheses. A separating
225        string can be specified by --om-separator (default empty).
226    
227    19. Improving the first n character searches.
228    
229    20. Turn case lists for horizontal and vertical white space into macros so that
230        they are defined only once.
231    
232    21. This set of changes together give more compatible Unicode case-folding
233        behaviour for characters that have more than one other case when UCP
234        support is available.
235    
236        (a) The Unicode property table now has offsets into a new table of sets of
237            three or more characters that are case-equivalent. The MultiStage2.py
238            script that generates these tables (the pcre_ucd.c file) now scans
239            CaseFolding.txt instead of UnicodeData.txt for character case
240            information.
241    
242        (b) The code for adding characters or ranges of characters to a character
243            class has been abstracted into a generalized function that also handles
244            case-independence. In UTF-mode with UCP support, this uses the new data
245            to handle characters with more than one other case.
246    
247        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
248            whose other case is greater than 256 are now correctly matched
249            caselessly. Previously, the high codepoint matched the low one, but not
250            vice versa.
251    
252        (d) The processing of \h, \H, \v, and \ in character classes now makes use
253            of the new class addition function, using character lists defined as
254            macros alongside the case definitions of 20 above.
255    
256        (e) Caseless back references now work with characters that have more than
257            one other case.
258    
259        (f) General caseless matching of characters with more than one other case
260            is supported.
261    
262    22. Unicode character properties were updated from Unicode 6.2.0
263    
264    23. Improved CMake support under Windows. Patch by Daniel Richard G.
265    
266    24. Add support for 32-bit character strings, and UTF-32
267    
268    25. Major JIT compiler update (code refactoring and bugfixing).
269        Experimental Sparc 32 support is added.
270    
271    26. Applied a modified version of Daniel Richard G's patch to create
272        pcre.h.generic and config.h.generic by "make" instead of in the
273        PrepareRelease script.
274    
275    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
276        pcre_compile.c when checking for a zero character.
277    
278    28. Introducing a native interface for JIT. Through this interface, the compiled
279        machine code can be directly executed. The purpose of this interface is to
280        provide fast pattern matching, so several sanity checks are not performed.
281        However, feature tests are still performed. The new interface provides
282        1.4x speedup compared to the old one.
283    
284    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
285        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
286        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
287    
288    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
289        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
290        the "old" RFC 2279). Instead, it ended up passing a negative length to
291        pcre_exec().
292    
293    31. Add support for GCC's visibility feature to hide internal functions.
294    
295    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
296        "unknown -C option" after outputting 0 or 1.
297    
298    33. There is now support for generating a code coverage report for the test
299        suite in environments where gcc is the compiler and lcov is installed. This
300        is mainly for the benefit of the developers.
301    
302    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
303        unaddressable using valgrind annotations, allowing valgrind to detect
304        invalid memory accesses. This is mainly for the benefit of the developers.
305    
306    25. (*UTF) can now be used to start a pattern in any of the three libraries.
307    
308    26. Give configure error if --enable-cpp but no C++ compiler found.
309    
310    
311    Version 8.31 06-July-2012
312    -------------------------
313    
314    1.  Fixing a wrong JIT test case and some compiler warnings.
315    
316    2.  Removed a bashism from the RunTest script.
317    
318    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
319        to unsigned type, result still unsigned" that was given by an MS compiler
320        on encountering the code "-sizeof(xxx)".
321    
322    4.  Partial matching support is added to the JIT compiler.
323    
324    5.  Fixed several bugs concerned with partial matching of items that consist
325        of more than one character:
326    
327        (a) /^(..)\1/ did not partially match "aba" because checking references was
328            done on an "all or nothing" basis. This also applied to repeated
329            references.
330    
331        (b) \R did not give a hard partial match if \r was found at the end of the
332            subject.
333    
334        (c) \X did not give a hard partial match after matching one or more
335            characters at the end of the subject.
336    
337        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
338            a partial match for the string "\r".
339    
340        (e) When newline was set to CRLF, the metacharacter "." did not recognize
341            a partial match for a CR character at the end of the subject string.
342    
343    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
344        running pcretest, the text "(JIT)" added to the output whenever JIT is
345        actually used to run the match.
346    
347    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
348        or /S+[+] with a digit between 1 and 7.
349    
350    8.  OP_NOT now supports any UTF character not just single-byte ones.
351    
352    9.  (*MARK) control verb is now supported by the JIT compiler.
353    
354    10. The command "./RunTest list" lists the available tests without actually
355        running any of them. (Because I keep forgetting what they all are.)
356    
357    11. Add PCRE_INFO_MAXLOOKBEHIND.
358    
359    12. Applied a (slightly modified) user-supplied patch that improves performance
360        when the heap is used for recursion (compiled with --disable-stack-for-
361        recursion). Instead of malloc and free for each heap frame each time a
362        logical recursion happens, frames are retained on a chain and re-used where
363        possible. This sometimes gives as much as 30% improvement.
364    
365    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
366        call.
367    
368    14. As documented, (*COMMIT) is now confined to within a positive assertion.
369    
370    15. It is now possible to link pcretest with libedit as an alternative to
371        libreadline.
372    
373    16. (*COMMIT) control verb is now supported by the JIT compiler.
374    
375    17. The Unicode data tables have been updated to Unicode 6.1.0.
376    
377    18. Added --file-list option to pcregrep.
378    
379    19. Added binary file support to pcregrep, including the -a, --binary-files,
380        -I, and --text options.
381    
382    20. The madvise function is renamed for posix_madvise for QNX compatibility
383        reasons. Fixed by Giuseppe D'Angelo.
384    
385    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
386    
387    22. Changed the option for creating symbolic links for 16-bit man pages from
388        -s to -sf so that re-installing does not cause issues.
389    
390    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
391    
392    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
393        matches in certain environments (the workspace was not being correctly
394        retained). Also added to pcre_dfa_exec() a simple plausibility check on
395        some of the workspace data at the beginning of a restart.
396    
397    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
398        was not doing so when it should - probably a typo introduced by SVN 528
399        (change 8.10/14).
400    
401    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
402        \w+ when the character tables indicated that \x{c4} was a word character.
403        There were several related cases, all because the tests for doing a table
404        lookup were testing for characters less than 127 instead of 255.
405    
406    27. If a pattern contains capturing parentheses that are not used in a match,
407        their slots in the ovector are set to -1. For those that are higher than
408        any matched groups, this happens at the end of processing. In the case when
409        there were back references that the ovector was too small to contain
410        (causing temporary malloc'd memory to be used during matching), and the
411        highest capturing number was not used, memory off the end of the ovector
412        was incorrectly being set to -1. (It was using the size of the temporary
413        memory instead of the true size.)
414    
415    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
416        ovector size, it uses memory at the end of the block that it has got.
417    
418    29. Check for an overlong MARK name and give an error at compile time. The
419        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
420    
421    30. JIT compiler update.
422    
423    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
424        Rill for the patch.
425    
426    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
427    
428    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
429    
430    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
431        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
432        was enabled.
433    
434    35. Improve JIT code generation for greedy plus quantifier.
435    
436    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
437        1 to "aa" instead of to an empty string. The bug affected repeated groups
438        that could potentially match an empty string.
439    
440    37. Optimizing single character iterators in JIT.
441    
442    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
443        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
444        codepoints that are too big for the mode are faulted, and in a UTF mode,
445        disallowed codepoints are also faulted.
446    
447    39. If PCRE was compiled with UTF support, in three places in the DFA
448        matcher there was code that should only have been obeyed in UTF mode, but
449        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
450        processing when bytes with values greater than 127 were present. In 16-bit
451        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
452        both cases the values are those that cannot be the first data item in a UTF
453        character. The three items that might have provoked this were recursions,
454        possessively repeated groups, and atomic groups.
455    
456    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
457        and pcregrep, because some OS require shared objects to be explicitly
458        passed to ld, causing the link step to fail if they are not.
459    
460    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
461        mode, patterns that started with \h* or \R* might be incorrectly matched.
462    
463    
464    Version 8.30 04-February-2012
465    -----------------------------
466    
467    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
468        name is defined in ctype.h.
469    
470    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
471        only in quite long subpatterns.
472    
473    3.  Removed the function pcre_info(), which has been obsolete and deprecated
474        since it was replaced by pcre_fullinfo() in February 2000.
475    
476    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
477        match a (*MARK), and the match failed at the start of the subject, a
478        reference to memory before the start of the subject could occur. This bug
479        was introduced by fix 17 of release 8.21.
480    
481    5.  A reference to an unset group with zero minimum repetition was giving
482        totally wrong answers (in non-JavaScript-compatibility mode). For example,
483        /(another)?(\1?)test/ matched against "hello world test". This bug was
484        introduced in release 8.13.
485    
486    6.  Add support for 16-bit character strings (a large amount of work involving
487        many changes and refactorings).
488    
489    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
490        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
491        from a file.
492    
493    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
494        rounding is not applied in this particular case).
495    
496    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
497        if they appear, or are escaped, in patterns.
498    
499    10. Get rid of a number of -Wunused-but-set-variable warnings.
500    
501    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
502        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
503        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
504        also returns the mark "x". This bug applied to capturing parentheses,
505        non-capturing parentheses, and atomic parentheses. It also applied to some
506        assertions.
507    
508    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
509        information out of configure.ac instead of relying on pcre.h.generic, which
510        is not stored in the repository.
511    
512    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
513        -lreadline.
514    
515    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
516    
517    15. Applied Graycode's patch to put the top-level frame on the stack rather
518        than the heap when not using the stack for recursion. This gives a
519        performance improvement in many cases when recursion is not deep.
520    
521    16. Experimental code added to "pcretest -C" to output the stack frame size.
522    
523    
524    Version 8.21 12-Dec-2011
525    ------------------------
526    
527    1.  Updating the JIT compiler.
528    
529    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
530        are added as well.
531    
532    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
533        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
534        calling _pcre_jit_exec. Some extra comments are added.
535    
536    4.  (*MARK) settings inside atomic groups that do not contain any capturing
537        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
538        was introduced by change 18 for 8.20.
539    
540    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
541        ECMA-262 standard.
542    
543    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
544        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
545        This bug was probably introduced by change 9 of 8.13.
546    
547    7.  While fixing 6 above, I noticed that a number of other items were being
548        incorrectly rejected as "not fixed length". This arose partly because newer
549        opcodes had not been added to the fixed-length checking code. I have (a)
550        corrected the bug and added tests for these items, and (b) arranged for an
551        error to occur if an unknown opcode is encountered while checking for fixed
552        length instead of just assuming "not fixed length". The items that were
553        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
554        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
555        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
556    
557    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
558        being incorrectly compiled and would have given unpredicatble results.
559    
560    9.  A possessively repeated subpattern with minimum repeat count greater than
561        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
562        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
563        the first (A) could occur when it should not.
564    
565    10. Add a cast and remove a redundant test from the code.
566    
567    11. JIT should use pcre_malloc/pcre_free for allocation.
568    
569    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
570        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
571        is anything other than /usr, -L is still shown).
572    
573    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
574    
575    14. Perl does not support \N without a following name in a [] class; PCRE now
576        also gives an error.
577    
578    15. If a forward reference was repeated with an upper limit of around 2000,
579        it caused the error "internal error: overran compiling workspace". The
580        maximum number of forward references (including repeats) was limited by the
581        internal workspace, and dependent on the LINK_SIZE. The code has been
582        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
583        the default depends on LINK_SIZE. There is a new upper limit (for safety)
584        of around 200,000 forward references. While doing this, I also speeded up
585        the filling in of repeated forward references.
586    
587    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
588        incorrectly expecting the subject to contain another "a" after the start.
589    
590    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
591        in the match, the SKIP should be ignored. This was not happening; instead
592        the SKIP was being treated as NOMATCH. For patterns such as
593        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
594        tested.
595    
596    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
597        now much more compatible with Perl, in particular in cases where the result
598        is a non-match for a non-anchored pattern. For example, if
599        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
600        "m", where previously it did not return a name. A side effect of this
601        change is that for partial matches, the last encountered mark name is
602        returned, as for non matches. A number of tests that were previously not
603        Perl-compatible have been moved into the Perl-compatible test files. The
604        refactoring has had the pleasing side effect of removing one argument from
605        the match() function, thus reducing its stack requirements.
606    
607    19. If the /S+ option was used in pcretest to study a pattern using JIT,
608        subsequent uses of /S (without +) incorrectly behaved like /S+.
609    
610    21. Retrieve executable code size support for the JIT compiler and fixing
611        some warnings.
612    
613    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
614        not work when the shorter character appeared right at the end of the
615        subject string.
616    
617    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
618        systems.
619    
620    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
621        output it when the /M option is used in pcretest.
622    
623    25. The CheckMan script was not being included in the distribution. Also, added
624        an explicit "perl" to run Perl scripts from the PrepareRelease script
625        because this is reportedly needed in Windows.
626    
627    26. If study data was being save in a file and studying had not found a set of
628        "starts with" bytes for the pattern, the data written to the file (though
629        never used) was taken from uninitialized memory and so caused valgrind to
630        complain.
631    
632    27. Updated RunTest.bat as provided by Sheri Pierce.
633    
634    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
635    
636    29. Computation of memory usage for the table of capturing group names was
637        giving an unnecessarily large value.
638    
639    
640    Version 8.20 21-Oct-2011
641    ------------------------
642    
643    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
644        a POSIX class. After further experiments with Perl, which convinced me that
645        Perl has bugs and confusions, a closing square bracket is no longer allowed
646        in a POSIX name. This bug also affected patterns with classes that started
647        with full stops.
648    
649    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
650        captured substring, but while checking the failing first alternative,
651        substring 1 is temporarily captured. If the output vector supplied to
652        pcre_exec() was not big enough for this capture, the yield of the function
653        was still zero ("insufficient space for captured substrings"). This cannot
654        be totally fixed without adding another stack variable, which seems a lot
655        of expense for a edge case. However, I have improved the situation in cases
656        such as /(a)(b)x|abc/ matched against "abc", where the return code
657        indicates that fewer than the maximum number of slots in the ovector have
658        been set.
659    
660    3.  Related to (2) above: when there are more back references in a pattern than
661        slots in the output vector, pcre_exec() uses temporary memory during
662        matching, and copies in the captures as far as possible afterwards. It was
663        using the entire output vector, but this conflicts with the specification
664        that only 2/3 is used for passing back captured substrings. Now it uses
665        only the first 2/3, for compatibility. This is, of course, another edge
666        case.
667    
668    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
669        main code base, and can be used by building with --enable-jit. When this is
670        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
671        runtime --no-jit option is given.
672    
673    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
674        ovector, the return from the function was zero, implying that there were
675        other matches that did not fit. The correct "exactly full" value is now
676        returned.
677    
678    6.  If a subpattern that was called recursively or as a subroutine contained
679        (*PRUNE) or any other control that caused it to give a non-standard return,
680        invalid errors such as "Error -26 (nested recursion at the same subject
681        position)" or even infinite loops could occur.
682    
683    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
684        computing the minimum length on reaching *ACCEPT, and so ended up with the
685        wrong value of 1 rather than 0. Further investigation indicates that
686        computing a minimum subject length in the presence of *ACCEPT is difficult
687        (think back references, subroutine calls), and so I have changed the code
688        so that no minimum is registered for a pattern that contains *ACCEPT.
689    
690    8.  If (*THEN) was present in the first (true) branch of a conditional group,
691        it was not handled as intended. [But see 16 below.]
692    
693    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
694        Sheri Pierce.
695    
696    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
697        the first byte in a match must be "a".
698    
699    11. Change 17 for 8.13 increased the recursion depth for patterns like
700        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
701        pattern contains any instances of (*THEN). If it does not, the old
702        optimizations are restored. It would be nice to do this on a per-group
703        basis, but at the moment that is not feasible.
704    
705    12. In some environments, the output of pcretest -C is CRLF terminated. This
706        broke RunTest's code that checks for the link size. A single white space
707        character after the value is now allowed for.
708    
709    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
710        For "fr", it uses the Windows-specific input and output files.
711    
712    14. If (*THEN) appeared in a group that was called recursively or as a
713        subroutine, it did not work as intended. [But see next item.]
714    
715    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
716        pattern fragments (but not containing any | characters). If A and B are
717        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
718        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
719        D. In other words, Perl considers parentheses that do not contain any |
720        characters to be part of a surrounding alternative, whereas PCRE was
721        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
722        differently. PCRE now behaves in the same way as Perl, except in the case
723        of subroutine/recursion calls such as (?1) which have in any case always
724        been different (but PCRE had them first :-).
725    
726    16. Related to 15 above: Perl does not treat the | in a conditional group as
727        creating alternatives. Such a group is treated in the same way as an
728        ordinary group without any | characters when processing (*THEN). PCRE has
729        been changed to match Perl's behaviour.
730    
731    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
732        RunGrepTest script failed.
733    
734    18. Change 22 for version 13 caused atomic groups to use more stack. This is
735        inevitable for groups that contain captures, but it can lead to a lot of
736        stack use in large patterns. The old behaviour has been restored for atomic
737        groups that do not contain any capturing parentheses.
738    
739    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
740        suppress the check for a minimum subject length at run time. (If it was
741        given to pcre_exec() or pcre_dfa_exec() it did work.)
742    
743    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
744        fail to work when decoding hex characters in data strings in EBCDIC
745        environments.
746    
747    21. It appears that in at least one Mac OS environment, the isxdigit() function
748        is implemented as a macro that evaluates to its argument more than once,
749        contravening the C 90 Standard (I haven't checked a later standard). There
750        was an instance in pcretest which caused it to go wrong when processing
751        \x{...} escapes in subject strings. The has been rewritten to avoid using
752        things like p++ in the argument of isxdigit().
753    
754    
755    Version 8.13 16-Aug-2011
756    ------------------------
757    
758    1.  The Unicode data tables have been updated to Unicode 6.0.0.
759    
760    2.  Two minor typos in pcre_internal.h have been fixed.
761    
762    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
763        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
764        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
765    
766    4.  There were a number of related bugs in the code for matching backrefences
767        caselessly in UTF-8 mode when codes for the characters concerned were
768        different numbers of bytes. For example, U+023A and U+2C65 are an upper
769        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
770        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
771        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
772        2-byte code at the end of the subject (it thought there wasn't enough data
773        left).
774    
775    5.  Comprehensive information about what went wrong is now returned by
776        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
777        as the output vector has at least 2 elements. The offset of the start of
778        the failing character and a reason code are placed in the vector.
779    
780    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
781        now returned is for the first byte of the failing character, instead of the
782        last byte inspected. This is an incompatible change, but I hope it is small
783        enough not to be a problem. It makes the returned offset consistent with
784        pcre_exec() and pcre_dfa_exec().
785    
786    7.  pcretest now gives a text phrase as well as the error number when
787        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
788        failure, the offset and reason code are output.
789    
790    8.  When \R was used with a maximizing quantifier it failed to skip backwards
791        over a \r\n pair if the subsequent match failed. Instead, it just skipped
792        back over a single character (\n). This seems wrong (because it treated the
793        two characters as a single entity when going forwards), conflicts with the
794        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
795        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
796        has been changed.
797    
798    9.  Some internal refactoring has changed the processing so that the handling
799        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
800        time (the PCRE_DOTALL option was changed this way some time ago: version
801        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
802        which was always a bit of a fudge. It also means that there is one less
803        argument for the match() function, which reduces its stack requirements
804        slightly. This change also fixes an incompatibility with Perl: the pattern
805        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
806    
807    10. More internal refactoring has drastically reduced the number of recursive
808        calls to match() for possessively repeated groups such as (abc)++ when
809        using pcre_exec().
810    
811    11. While implementing 10, a number of bugs in the handling of groups were
812        discovered and fixed:
813    
814        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
815        (a|)*(?1) gave a compile-time internal error.
816        ((a|)+)+  did not notice that the outer group could match an empty string.
817        (^a|^)+   was not marked as anchored.
818        (.*a|.*)+ was not marked as matching at start or after a newline.
819    
820    12. Yet more internal refactoring has removed another argument from the match()
821        function. Special calls to this function are now indicated by setting a
822        value in a variable in the "match data" data block.
823    
824    13. Be more explicit in pcre_study() instead of relying on "default" for
825        opcodes that mean there is no starting character; this means that when new
826        ones are added and accidentally left out of pcre_study(), testing should
827        pick them up.
828    
829    14. The -s option of pcretest has been documented for ages as being an old
830        synonym of -m (show memory usage). I have changed it to mean "force study
831        for every regex", that is, assume /S for every regex. This is similar to -i
832        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
833        using it. It makes it easier to run collections of tests with and without
834        study enabled, and thereby test pcre_study() more easily. All the standard
835        tests are now run with and without -s (but some patterns can be marked as
836        "never study" - see 20 below).
837    
838    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
839        restoration of the capturing data to the outer values was not happening
840        correctly.
841    
842    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
843        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
844        pattern had matched an empty string, and so incorrectly returned a no
845        match.
846    
847    17. There was optimizing code for the last branch of non-capturing parentheses,
848        and also for the obeyed branch of a conditional subexpression, which used
849        tail recursion to cut down on stack usage. Unfortunately, now that there is
850        the possibility of (*THEN) occurring in these branches, tail recursion is
851        no longer possible because the return has to be checked for (*THEN). These
852        two optimizations have therefore been removed. [But see 8.20/11 above.]
853    
854    18. If a pattern containing \R was studied, it was assumed that \R always
855        matched two bytes, thus causing the minimum subject length to be
856        incorrectly computed because \R can also match just one byte.
857    
858    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
859        was incorrectly computed.
860    
861    20. If /S is present twice on a test pattern in pcretest input, it now
862        *disables* studying, thereby overriding the use of -s on the command line
863        (see 14 above). This is necessary for one or two tests to keep the output
864        identical in both cases.
865    
866    21. When (*ACCEPT) was used in an assertion that matched an empty string and
867        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
868    
869    22. When an atomic group that contained a capturing parenthesis was
870        successfully matched, but the branch in which it appeared failed, the
871        capturing was not being forgotten if a higher numbered group was later
872        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
873        group 1 to "a", when in fact it should be unset. This applied to multi-
874        branched capturing and non-capturing groups, repeated or not, and also to
875        positive assertions (capturing in negative assertions does not happen
876        in PCRE) and also to nested atomic groups.
877    
878    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
879        subject after a captured substring, to make it easier to tell which of a
880        number of identical substrings has been captured.
881    
882    24. The way atomic groups are processed by pcre_exec() has been changed so that
883        if they are repeated, backtracking one repetition now resets captured
884        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
885        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
886        "aaa". Previously, it would have been "a". As part of this code
887        refactoring, the way recursive calls are handled has also been changed.
888    
889    25. If an assertion condition captured any substrings, they were not passed
890        back unless some other capturing happened later. For example, if
891        (?(?=(a))a) was matched against "a", no capturing was returned.
892    
893    26. When studying a pattern that contained subroutine calls or assertions,
894        the code for finding the minimum length of a possible match was handling
895        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
896        group 1 called group 2 while simultaneously a separate group 2 called group
897        1). A stack overflow occurred in this case. I have fixed this by limiting
898        the recursion depth to 10.
899    
900    27. Updated RunTest.bat in the distribution to the version supplied by Tom
901        Fortmann. This supports explicit test numbers on the command line, and has
902        argument validation and error reporting.
903    
904    28. An instance of \X with an unlimited repeat could fail if at any point the
905        first character it looked at was a mark character.
906    
907    29. Some minor code refactoring concerning Unicode properties and scripts
908        should reduce the stack requirement of match() slightly.
909    
910    30. Added the '=' option to pcretest to check the setting of unused capturing
911        slots at the end of the pattern, which are documented as being -1, but are
912        not included in the return count.
913    
914    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
915        compiled something random. Now it gives a compile-time error (as does
916        Perl).
917    
918    32. A *MARK encountered during the processing of a positive assertion is now
919        recorded and passed back (compatible with Perl).
920    
921    33. If --only-matching or --colour was set on a pcregrep call whose pattern
922        had alternative anchored branches, the search for a second match in a line
923        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
924        matched the line "0102" twice. The same bug affected patterns that started
925        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
926        twice.
927    
928    34. Previously, PCRE did not allow quantification of assertions. However, Perl
929        does, and because of capturing effects, quantifying parenthesized
930        assertions may at times be useful. Quantifiers are now allowed for
931        parenthesized assertions.
932    
933    35. A minor code tidy in pcre_compile() when checking options for \R usage.
934    
935    36. \g was being checked for fancy things in a character class, when it should
936        just be a literal "g".
937    
938    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
939        appearance of a nested POSIX class supersedes an apparent external class.
940        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
941        unescaped square brackets may also appear as part of class names. For
942        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
943        more like Perl. (But see 8.20/1 above.)
944    
945    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
946        was because it thought it was \N{name}, which is not supported).
947    
948    39. Add minix to OS list not supporting the -S option in pcretest.
949    
950    40. PCRE tries to detect cases of infinite recursion at compile time, but it
951        cannot analyze patterns in sufficient detail to catch mutual recursions
952        such as ((?1))((?2)). There is now a runtime test that gives an error if a
953        subgroup is called recursively as a subpattern for a second time at the
954        same position in the subject string. In previous releases this might have
955        been caught by the recursion limit, or it might have run out of stack.
956    
957    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
958        happen only once. PCRE was, however incorrectly giving a compile time error
959        "recursive call could loop indefinitely" because it cannot analyze the
960        pattern in sufficient detail. The compile time test no longer happens when
961        PCRE is compiling a conditional subpattern, but actual runaway loops are
962        now caught at runtime (see 40 above).
963    
964    42. It seems that Perl allows any characters other than a closing parenthesis
965        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
966        has been changed to be the same.
967    
968    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
969        as not to get warnings when autogen.sh is called. Also changed
970        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
971    
972    44. To help people who use pcregrep to scan files containing exceedingly long
973        lines, the following changes have been made:
974    
975        (a) The default value of the buffer size parameter has been increased from
976            8K to 20K. (The actual buffer used is three times this size.)
977    
978        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
979            PCRE is built.
980    
981        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
982            to be set at run time.
983    
984        (d) Numerical values in pcregrep options can be followed by K or M, for
985            example --buffer-size=50K.
986    
987        (e) If a line being scanned overflows pcregrep's buffer, an error is now
988            given and the return code is set to 2.
989    
990    45. Add a pointer to the latest mark to the callout data block.
991    
992    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
993        partial match of an empty string instead of no match. This was specific to
994        the use of ".".
995    
996    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
997        complete match instead of a partial match. This bug was dependent on both
998        the PCRE_UTF8 and PCRE_DOTALL options being set.
999    
1000    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1001        starting byte set, because \b was not being ignored.
1002    
1003    
1004    Version 8.12 15-Jan-2011
1005    ------------------------
1006    
1007    1.  Fixed some typos in the markup of the man pages, and wrote a script that
1008        checks for such things as part of the documentation building process.
1009    
1010    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
1011        --match-limit and --recursion-limit options (added for 8.11). In
1012        particular, this made one of the standard tests fail. (The integer value
1013        went into the wrong half of a long int.)
1014    
1015    3.  If the --colour option was given to pcregrep with -v (invert match), it
1016        did strange things, either producing crazy output, or crashing. It should,
1017        of course, ignore a request for colour when reporting lines that do not
1018        match.
1019    
1020    4.  Another pcregrep bug caused similar problems if --colour was specified with
1021        -M (multiline) and the pattern match finished with a line ending.
1022    
1023    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
1024        matched in multiline mode, the following line was shown as part of the
1025        match. This seems wrong, so I have changed it.
1026    
1027    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
1028        the check for further matches in the same line (so they could be coloured)
1029        to overrun the end of the current line. If another match was found, it was
1030        incorrectly shown (and then shown again when found in the next line).
1031    
1032    7.  If pcregrep was compiled under Windows, there was a reference to the
1033        function pcregrep_exit() before it was defined. I am assuming this was
1034        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1035        reported by a user. I've moved the definition above the reference.
1036    
1037    
1038    Version 8.11 10-Dec-2010
1039    ------------------------
1040    
1041    1.  (*THEN) was not working properly if there were untried alternatives prior
1042        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1043        backtracked to try for "b" instead of moving to the next alternative branch
1044        at the same level (in this case, to look for "c"). The Perl documentation
1045        is clear that when (*THEN) is backtracked onto, it goes to the "next
1046        alternative in the innermost enclosing group".
1047    
1048    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1049        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
1050        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1051        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1052        (*THEN).
1053    
1054    3.  If \s appeared in a character class, it removed the VT character from
1055        the class, even if it had been included by some previous item, for example
1056        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1057        of \s, but is part of the POSIX "space" class.)
1058    
1059    4.  A partial match never returns an empty string (because you can always
1060        match an empty string at the end of the subject); however the checking for
1061        an empty string was starting at the "start of match" point. This has been
1062        changed to the "earliest inspected character" point, because the returned
1063        data for a partial match starts at this character. This means that, for
1064        example, /(?<=abc)def/ gives a partial match for the subject "abc"
1065        (previously it gave "no match").
1066    
1067    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1068        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1069        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1070        has an implication that the given string is incomplete (because a partial
1071        match is preferred over a full match). For this reason, these items now
1072        give a partial match in this situation. [Aside: previously, the one case
1073        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1074        match rather than a full match, which was wrong by the old rules, but is
1075        now correct.]
1076    
1077    6.  There was a bug in the handling of #-introduced comments, recognized when
1078        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1079        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1080        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1081        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1082        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1083        places in pcre_compile().
1084    
1085    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
1086        comments when looking ahead for named forward references to subpatterns,
1087        the only newline sequence it recognized was NL. It now handles newlines
1088        according to the set newline convention.
1089    
1090    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1091        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1092        cater for a lack of strerror(). These oversights have been fixed.
1093    
1094    9.  Added --match-limit and --recursion-limit to pcregrep.
1095    
1096    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1097    
1098    11. When the -o option was used, pcregrep was setting a return code of 1, even
1099        when matches were found, and --line-buffered was not being honoured.
1100    
1101    12. Added an optional parentheses number to the -o and --only-matching options
1102        of pcregrep.
1103    
1104    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1105        can match an empty string. The code to do it in pcretest and pcredemo
1106        needed fixing:
1107    
1108        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1109            only one byte after an empty string match just before CRLF (this case
1110            just got forgotten; "any" and "anycrlf" were OK).
1111    
1112        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1113            mode when an empty string match preceded an ASCII character followed by
1114            a non-ASCII character. (The code for advancing by one character rather
1115            than one byte was nonsense.)
1116    
1117        (c) The pcredemo.c sample program did not have any code at all to handle
1118            the cases when CRLF is a valid newline sequence.
1119    
1120    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1121        as a starting offset was within the subject string. There is now a new
1122        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1123        negative or greater than the length of the string. In order to test this,
1124        pcretest is extended to allow the setting of negative starting offsets.
1125    
1126    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1127        starting offset points to the beginning of a UTF-8 character was
1128        unnecessarily clumsy. I tidied it up.
1129    
1130    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1131        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1132    
1133    17. Nobody had reported that the --include_dir option, which was added in
1134        release 7.7 should have been called --include-dir (hyphen, not underscore)
1135        for compatibility with GNU grep. I have changed it to --include-dir, but
1136        left --include_dir as an undocumented synonym, and the same for
1137        --exclude-dir, though that is not available in GNU grep, at least as of
1138        release 2.5.4.
1139    
1140    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1141        characters from a string of bytes) have been redefined so as not to use
1142        loops, in order to improve performance in some environments. At the same
1143        time, I abstracted some of the common code into auxiliary macros to save
1144        repetition (this should not affect the compiled code).
1145    
1146    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1147        compile-time error is now given if \c is not followed by an ASCII
1148        character, that is, a byte less than 128. (In EBCDIC mode, the code is
1149        different, and any byte value is allowed.)
1150    
1151    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1152        START_OPTIMIZE option, which is now allowed at compile time - but just
1153        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1154        to pcregrep and other applications that have no direct access to PCRE
1155        options. The new /Y option in pcretest sets this option when calling
1156        pcre_compile().
1157    
1158    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1159        back references. Groups containing recursive back references were forced to
1160        be atomic by that change, but in the case of named groups, the amount of
1161        memory required was incorrectly computed, leading to "Failed: internal
1162        error: code overflow". This has been fixed.
1163    
1164    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1165        pcretest.c, to avoid build problems in some Borland environments.
1166    
1167    
1168    Version 8.10 25-Jun-2010
1169    ------------------------
1170    
1171    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1172        THEN.
1173    
1174    2.  (*ACCEPT) was not working when inside an atomic group.
1175    
1176    3.  Inside a character class, \B is treated as a literal by default, but
1177        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1178        causes the error). The code is unchanged, but I tidied the documentation.
1179    
1180    4.  Inside a character class, PCRE always treated \R and \X as literals,
1181        whereas Perl faults them if its -w option is set. I have changed PCRE so
1182        that it faults them when PCRE_EXTRA is set.
1183    
1184    5.  Added support for \N, which always matches any character other than
1185        newline. (It is the same as "." when PCRE_DOTALL is not set.)
1186    
1187    6.  When compiling pcregrep with newer versions of gcc which may have
1188        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1189        declared with attribute warn_unused_result" were given. Just casting the
1190        result to (void) does not stop the warnings; a more elaborate fudge is
1191        needed. I've used a macro to implement this.
1192    
1193    7.  Minor change to pcretest.c to avoid a compiler warning.
1194    
1195    8.  Added four artifical Unicode properties to help with an option to make
1196        \s etc use properties (see next item). The new properties are: Xan
1197        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1198    
1199    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1200        use Unicode properties. (*UCP) at the start of a pattern can be used to set
1201        this option. Modified pcretest to add /W to test this facility. Added
1202        REG_UCP to make it available via the POSIX interface.
1203    
1204    10. Added --line-buffered to pcregrep.
1205    
1206    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1207        studied, and the match started with a letter with a code point greater than
1208        127 whose first byte was different to the first byte of the other case of
1209        the letter, the other case of this starting letter was not recognized
1210        (#976).
1211    
1212    12. If a pattern that was studied started with a repeated Unicode property
1213        test, for example, \p{Nd}+, there was the theoretical possibility of
1214        setting up an incorrect bitmap of starting bytes, but fortunately it could
1215        not have actually happened in practice until change 8 above was made (it
1216        added property types that matched character-matching opcodes).
1217    
1218    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1219        possible starting bytes for non-anchored patterns.
1220    
1221    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1222        \R, and also a number of cases that involve Unicode properties, both
1223        explicit and implicit when PCRE_UCP is set.
1224    
1225    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1226        input, it could crash or give wrong results if characters with values
1227        greater than 0xc0 were present in the subject string. (Detail: it assumed
1228        UTF-8 input when processing these items.)
1229    
1230    16. Added a lot of (int) casts to avoid compiler warnings in systems where
1231        size_t is 64-bit (#991).
1232    
1233    17. Added a check for running out of memory when PCRE is compiled with
1234        --disable-stack-for-recursion (#990).
1235    
1236    18. If the last data line in a file for pcretest does not have a newline on
1237        the end, a newline was missing in the output.
1238    
1239    19. The default pcre_chartables.c file recognizes only ASCII characters (values
1240        less than 128) in its various bitmaps. However, there is a facility for
1241        generating tables according to the current locale when PCRE is compiled. It
1242        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1243        characters, are recognized by isspace() and therefore were getting set in
1244        these tables, and indeed these tables seem to approximate to ISO 8859. This
1245        caused a problem in UTF-8 mode when pcre_study() was used to create a list
1246        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1247        which of course cannot start UTF-8 characters. I have changed the code so
1248        that only real ASCII characters (less than 128) and the correct starting
1249        bytes for UTF-8 encodings are set for characters greater than 127 when in
1250        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1251        altogether.)
1252    
1253    20. Added the /T option to pcretest so as to be able to run tests with non-
1254        standard character tables, thus making it possible to include the tests
1255        used for 19 above in the standard set of tests.
1256    
1257    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1258        reference to a subpattern the other side of a comment that contains an
1259        opening parenthesis caused either an internal compiling error, or a
1260        reference to the wrong subpattern.
1261    
1262    
1263    Version 8.02 19-Mar-2010
1264  ------------------------  ------------------------
1265    
1266  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.
1267    
1268    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
1269        configured.
1270    
1271    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
1272        original author of that file, following a query about its status.
1273    
1274    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
1275        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1276    
1277    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1278        quantifier applied to a forward-referencing subroutine call, could compile
1279        incorrect code or give the error "internal error: previously-checked
1280        referenced subpattern not found".
1281    
1282    6.  Both MS Visual Studio and Symbian OS have problems with initializing
1283        variables to point to external functions. For these systems, therefore,
1284        pcre_malloc etc. are now initialized to local functions that call the
1285        relevant global functions.
1286    
1287    7.  There were two entries missing in the vectors called coptable and poptable
1288        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1289        I've fixed the data, and added a kludgy way of testing at compile time that
1290        the lengths are correct (equal to the number of opcodes).
1291    
1292    8.  Following on from 7, I added a similar kludge to check the length of the
1293        eint vector in pcreposix.c.
1294    
1295    9.  Error texts for pcre_compile() are held as one long string to avoid too
1296        much relocation at load time. To find a text, the string is searched,
1297        counting zeros. There was no check for running off the end of the string,
1298        which could happen if a new error number was added without updating the
1299        string.
1300    
1301    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1302    
1303    11. \K was not working if it appeared in an atomic group or in a group that
1304        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1305        \K is "not well defined" if used in an assertion. PCRE now accepts it if
1306        the assertion is positive, but not if it is negative.
1307    
1308    12. Change 11 fortuitously reduced the size of the stack frame used in the
1309        "match()" function of pcre_exec.c by one pointer. Forthcoming
1310        implementation of support for (*MARK) will need an extra pointer on the
1311        stack; I have reserved it now, so that the stack frame size does not
1312        decrease.
1313    
1314    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1315        item in branch that calls a recursion is a subroutine call - as in the
1316        second branch in the above example - was incorrectly given the compile-
1317        time error "recursive call could loop indefinitely" because pcre_compile()
1318        was not correctly checking the subroutine for matching a non-empty string.
1319    
1320    14. The checks for overrunning compiling workspace could trigger after an
1321        overrun had occurred. This is a "should never occur" error, but it can be
1322        triggered by pathological patterns such as hundreds of nested parentheses.
1323        The checks now trigger 100 bytes before the end of the workspace.
1324    
1325    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1326    
1327    
1328  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
1329  ------------------------  ------------------------

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