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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.31
5    -----------------------------
6    
7    1.  Fixing a wrong JIT test case and some compiler warnings.
8    
9    2.  Removed a bashism from the RunTest script.
10    
11    
12    Version 8.30 04-February-2012
13    -----------------------------
14    
15    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
16        name is defined in ctype.h.
17    
18    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
19        only in quite long subpatterns.
20    
21    3.  Removed the function pcre_info(), which has been obsolete and deprecated
22        since it was replaced by pcre_fullinfo() in February 2000.
23    
24    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
25        match a (*MARK), and the match failed at the start of the subject, a
26        reference to memory before the start of the subject could occur. This bug
27        was introduced by fix 17 of release 8.21.
28    
29    5.  A reference to an unset group with zero minimum repetition was giving
30        totally wrong answers (in non-JavaScript-compatibility mode). For example,
31        /(another)?(\1?)test/ matched against "hello world test". This bug was
32        introduced in release 8.13.
33    
34    6.  Add support for 16-bit character strings (a large amount of work involving
35        many changes and refactorings).
36    
37    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
38        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
39        from a file.
40    
41    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
42        rounding is not applied in this particular case).
43    
44    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
45        if they appear, or are escaped, in patterns.
46    
47    10. Get rid of a number of -Wunused-but-set-variable warnings.
48    
49    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
50        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
51        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
52        also returns the mark "x". This bug applied to capturing parentheses,
53        non-capturing parentheses, and atomic parentheses. It also applied to some
54        assertions.
55    
56    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
57        information out of configure.ac instead of relying on pcre.h.generic, which
58        is not stored in the repository.
59    
60    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
61        -lreadline.
62    
63    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
64    
65    15. Applied Graycode's patch to put the top-level frame on the stack rather
66        than the heap when not using the stack for recursion. This gives a
67        performance improvement in many cases when recursion is not deep.
68    
69    16. Experimental code added to "pcretest -C" to output the stack frame size.
70    
71    
72    Version 8.21 12-Dec-2011
73    ------------------------
74    
75    1.  Updating the JIT compiler.
76    
77    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
78        are added as well.
79    
80    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
81        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
82        calling _pcre_jit_exec. Some extra comments are added.
83    
84    4.  (*MARK) settings inside atomic groups that do not contain any capturing
85        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
86        was introduced by change 18 for 8.20.
87    
88    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
89        ECMA-262 standard.
90    
91    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
92        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
93        This bug was probably introduced by change 9 of 8.13.
94    
95    7.  While fixing 6 above, I noticed that a number of other items were being
96        incorrectly rejected as "not fixed length". This arose partly because newer
97        opcodes had not been added to the fixed-length checking code. I have (a)
98        corrected the bug and added tests for these items, and (b) arranged for an
99        error to occur if an unknown opcode is encountered while checking for fixed
100        length instead of just assuming "not fixed length". The items that were
101        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
102        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
103        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
104    
105    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
106        being incorrectly compiled and would have given unpredicatble results.
107    
108    9.  A possessively repeated subpattern with minimum repeat count greater than
109        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
110        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
111        the first (A) could occur when it should not.
112    
113    10. Add a cast and remove a redundant test from the code.
114    
115    11. JIT should use pcre_malloc/pcre_free for allocation.
116    
117    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
118        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
119        is anything other than /usr, -L is still shown).
120    
121    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
122    
123    14. Perl does not support \N without a following name in a [] class; PCRE now
124        also gives an error.
125    
126    15. If a forward reference was repeated with an upper limit of around 2000,
127        it caused the error "internal error: overran compiling workspace". The
128        maximum number of forward references (including repeats) was limited by the
129        internal workspace, and dependent on the LINK_SIZE. The code has been
130        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
131        the default depends on LINK_SIZE. There is a new upper limit (for safety)
132        of around 200,000 forward references. While doing this, I also speeded up
133        the filling in of repeated forward references.
134    
135    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
136        incorrectly expecting the subject to contain another "a" after the start.
137    
138    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
139        in the match, the SKIP should be ignored. This was not happening; instead
140        the SKIP was being treated as NOMATCH. For patterns such as
141        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
142        tested.
143    
144    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
145        now much more compatible with Perl, in particular in cases where the result
146        is a non-match for a non-anchored pattern. For example, if
147        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
148        "m", where previously it did not return a name. A side effect of this
149        change is that for partial matches, the last encountered mark name is
150        returned, as for non matches. A number of tests that were previously not
151        Perl-compatible have been moved into the Perl-compatible test files. The
152        refactoring has had the pleasing side effect of removing one argument from
153        the match() function, thus reducing its stack requirements.
154    
155    19. If the /S+ option was used in pcretest to study a pattern using JIT,
156        subsequent uses of /S (without +) incorrectly behaved like /S+.
157    
158    21. Retrieve executable code size support for the JIT compiler and fixing
159        some warnings.
160    
161    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
162        not work when the shorter character appeared right at the end of the
163        subject string.
164    
165    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
166        systems.
167    
168    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
169        output it when the /M option is used in pcretest.
170    
171    25. The CheckMan script was not being included in the distribution. Also, added
172        an explicit "perl" to run Perl scripts from the PrepareRelease script
173        because this is reportedly needed in Windows.
174    
175    26. If study data was being save in a file and studying had not found a set of
176        "starts with" bytes for the pattern, the data written to the file (though
177        never used) was taken from uninitialized memory and so caused valgrind to
178        complain.
179    
180    27. Updated RunTest.bat as provided by Sheri Pierce.
181    
182    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
183    
184    29. Computation of memory usage for the table of capturing group names was
185        giving an unnecessarily large value.
186    
187    
188    Version 8.20 21-Oct-2011
189    ------------------------
190    
191    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
192        a POSIX class. After further experiments with Perl, which convinced me that
193        Perl has bugs and confusions, a closing square bracket is no longer allowed
194        in a POSIX name. This bug also affected patterns with classes that started
195        with full stops.
196    
197    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
198        captured substring, but while checking the failing first alternative,
199        substring 1 is temporarily captured. If the output vector supplied to
200        pcre_exec() was not big enough for this capture, the yield of the function
201        was still zero ("insufficient space for captured substrings"). This cannot
202        be totally fixed without adding another stack variable, which seems a lot
203        of expense for a edge case. However, I have improved the situation in cases
204        such as /(a)(b)x|abc/ matched against "abc", where the return code
205        indicates that fewer than the maximum number of slots in the ovector have
206        been set.
207    
208    3.  Related to (2) above: when there are more back references in a pattern than
209        slots in the output vector, pcre_exec() uses temporary memory during
210        matching, and copies in the captures as far as possible afterwards. It was
211        using the entire output vector, but this conflicts with the specification
212        that only 2/3 is used for passing back captured substrings. Now it uses
213        only the first 2/3, for compatibility. This is, of course, another edge
214        case.
215    
216    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
217        main code base, and can be used by building with --enable-jit. When this is
218        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
219        runtime --no-jit option is given.
220    
221    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
222        ovector, the return from the function was zero, implying that there were
223        other matches that did not fit. The correct "exactly full" value is now
224        returned.
225    
226    6.  If a subpattern that was called recursively or as a subroutine contained
227        (*PRUNE) or any other control that caused it to give a non-standard return,
228        invalid errors such as "Error -26 (nested recursion at the same subject
229        position)" or even infinite loops could occur.
230    
231    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
232        computing the minimum length on reaching *ACCEPT, and so ended up with the
233        wrong value of 1 rather than 0. Further investigation indicates that
234        computing a minimum subject length in the presence of *ACCEPT is difficult
235        (think back references, subroutine calls), and so I have changed the code
236        so that no minimum is registered for a pattern that contains *ACCEPT.
237    
238    8.  If (*THEN) was present in the first (true) branch of a conditional group,
239        it was not handled as intended. [But see 16 below.]
240    
241    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
242        Sheri Pierce.
243    
244    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
245        the first byte in a match must be "a".
246    
247    11. Change 17 for 8.13 increased the recursion depth for patterns like
248        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
249        pattern contains any instances of (*THEN). If it does not, the old
250        optimizations are restored. It would be nice to do this on a per-group
251        basis, but at the moment that is not feasible.
252    
253    12. In some environments, the output of pcretest -C is CRLF terminated. This
254        broke RunTest's code that checks for the link size. A single white space
255        character after the value is now allowed for.
256    
257    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
258        For "fr", it uses the Windows-specific input and output files.
259    
260    14. If (*THEN) appeared in a group that was called recursively or as a
261        subroutine, it did not work as intended. [But see next item.]
262    
263    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
264        pattern fragments (but not containing any | characters). If A and B are
265        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
266        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
267        D. In other words, Perl considers parentheses that do not contain any |
268        characters to be part of a surrounding alternative, whereas PCRE was
269        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
270        differently. PCRE now behaves in the same way as Perl, except in the case
271        of subroutine/recursion calls such as (?1) which have in any case always
272        been different (but PCRE had them first :-).
273    
274    16. Related to 15 above: Perl does not treat the | in a conditional group as
275        creating alternatives. Such a group is treated in the same way as an
276        ordinary group without any | characters when processing (*THEN). PCRE has
277        been changed to match Perl's behaviour.
278    
279    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
280        RunGrepTest script failed.
281    
282    18. Change 22 for version 13 caused atomic groups to use more stack. This is
283        inevitable for groups that contain captures, but it can lead to a lot of
284        stack use in large patterns. The old behaviour has been restored for atomic
285        groups that do not contain any capturing parentheses.
286    
287    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
288        suppress the check for a minimum subject length at run time. (If it was
289        given to pcre_exec() or pcre_dfa_exec() it did work.)
290    
291    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
292        fail to work when decoding hex characters in data strings in EBCDIC
293        environments.
294    
295    21. It appears that in at least one Mac OS environment, the isxdigit() function
296        is implemented as a macro that evaluates to its argument more than once,
297        contravening the C 90 Standard (I haven't checked a later standard). There
298        was an instance in pcretest which caused it to go wrong when processing
299        \x{...} escapes in subject strings. The has been rewritten to avoid using
300        things like p++ in the argument of isxdigit().
301    
302    
303    Version 8.13 16-Aug-2011
304    ------------------------
305    
306    1.  The Unicode data tables have been updated to Unicode 6.0.0.
307    
308    2.  Two minor typos in pcre_internal.h have been fixed.
309    
310    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
311        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
312        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
313    
314    4.  There were a number of related bugs in the code for matching backrefences
315        caselessly in UTF-8 mode when codes for the characters concerned were
316        different numbers of bytes. For example, U+023A and U+2C65 are an upper
317        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
318        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
319        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
320        2-byte code at the end of the subject (it thought there wasn't enough data
321        left).
322    
323    5.  Comprehensive information about what went wrong is now returned by
324        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
325        as the output vector has at least 2 elements. The offset of the start of
326        the failing character and a reason code are placed in the vector.
327    
328    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
329        now returned is for the first byte of the failing character, instead of the
330        last byte inspected. This is an incompatible change, but I hope it is small
331        enough not to be a problem. It makes the returned offset consistent with
332        pcre_exec() and pcre_dfa_exec().
333    
334    7.  pcretest now gives a text phrase as well as the error number when
335        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
336        failure, the offset and reason code are output.
337    
338    8.  When \R was used with a maximizing quantifier it failed to skip backwards
339        over a \r\n pair if the subsequent match failed. Instead, it just skipped
340        back over a single character (\n). This seems wrong (because it treated the
341        two characters as a single entity when going forwards), conflicts with the
342        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
343        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
344        has been changed.
345    
346    9.  Some internal refactoring has changed the processing so that the handling
347        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
348        time (the PCRE_DOTALL option was changed this way some time ago: version
349        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
350        which was always a bit of a fudge. It also means that there is one less
351        argument for the match() function, which reduces its stack requirements
352        slightly. This change also fixes an incompatibility with Perl: the pattern
353        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
354    
355    10. More internal refactoring has drastically reduced the number of recursive
356        calls to match() for possessively repeated groups such as (abc)++ when
357        using pcre_exec().
358    
359    11. While implementing 10, a number of bugs in the handling of groups were
360        discovered and fixed:
361    
362        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
363        (a|)*(?1) gave a compile-time internal error.
364        ((a|)+)+  did not notice that the outer group could match an empty string.
365        (^a|^)+   was not marked as anchored.
366        (.*a|.*)+ was not marked as matching at start or after a newline.
367    
368    12. Yet more internal refactoring has removed another argument from the match()
369        function. Special calls to this function are now indicated by setting a
370        value in a variable in the "match data" data block.
371    
372    13. Be more explicit in pcre_study() instead of relying on "default" for
373        opcodes that mean there is no starting character; this means that when new
374        ones are added and accidentally left out of pcre_study(), testing should
375        pick them up.
376    
377    14. The -s option of pcretest has been documented for ages as being an old
378        synonym of -m (show memory usage). I have changed it to mean "force study
379        for every regex", that is, assume /S for every regex. This is similar to -i
380        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
381        using it. It makes it easier to run collections of tests with and without
382        study enabled, and thereby test pcre_study() more easily. All the standard
383        tests are now run with and without -s (but some patterns can be marked as
384        "never study" - see 20 below).
385    
386    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
387        restoration of the capturing data to the outer values was not happening
388        correctly.
389    
390    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
391        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
392        pattern had matched an empty string, and so incorrectly returned a no
393        match.
394    
395    17. There was optimizing code for the last branch of non-capturing parentheses,
396        and also for the obeyed branch of a conditional subexpression, which used
397        tail recursion to cut down on stack usage. Unfortunately, now that there is
398        the possibility of (*THEN) occurring in these branches, tail recursion is
399        no longer possible because the return has to be checked for (*THEN). These
400        two optimizations have therefore been removed. [But see 8.20/11 above.]
401    
402    18. If a pattern containing \R was studied, it was assumed that \R always
403        matched two bytes, thus causing the minimum subject length to be
404        incorrectly computed because \R can also match just one byte.
405    
406    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
407        was incorrectly computed.
408    
409    20. If /S is present twice on a test pattern in pcretest input, it now
410        *disables* studying, thereby overriding the use of -s on the command line
411        (see 14 above). This is necessary for one or two tests to keep the output
412        identical in both cases.
413    
414    21. When (*ACCEPT) was used in an assertion that matched an empty string and
415        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
416    
417    22. When an atomic group that contained a capturing parenthesis was
418        successfully matched, but the branch in which it appeared failed, the
419        capturing was not being forgotten if a higher numbered group was later
420        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
421        group 1 to "a", when in fact it should be unset. This applied to multi-
422        branched capturing and non-capturing groups, repeated or not, and also to
423        positive assertions (capturing in negative assertions does not happen
424        in PCRE) and also to nested atomic groups.
425    
426    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
427        subject after a captured substring, to make it easier to tell which of a
428        number of identical substrings has been captured.
429    
430    24. The way atomic groups are processed by pcre_exec() has been changed so that
431        if they are repeated, backtracking one repetition now resets captured
432        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
433        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
434        "aaa". Previously, it would have been "a". As part of this code
435        refactoring, the way recursive calls are handled has also been changed.
436    
437    25. If an assertion condition captured any substrings, they were not passed
438        back unless some other capturing happened later. For example, if
439        (?(?=(a))a) was matched against "a", no capturing was returned.
440    
441    26. When studying a pattern that contained subroutine calls or assertions,
442        the code for finding the minimum length of a possible match was handling
443        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
444        group 1 called group 2 while simultaneously a separate group 2 called group
445        1). A stack overflow occurred in this case. I have fixed this by limiting
446        the recursion depth to 10.
447    
448    27. Updated RunTest.bat in the distribution to the version supplied by Tom
449        Fortmann. This supports explicit test numbers on the command line, and has
450        argument validation and error reporting.
451    
452    28. An instance of \X with an unlimited repeat could fail if at any point the
453        first character it looked at was a mark character.
454    
455    29. Some minor code refactoring concerning Unicode properties and scripts
456        should reduce the stack requirement of match() slightly.
457    
458    30. Added the '=' option to pcretest to check the setting of unused capturing
459        slots at the end of the pattern, which are documented as being -1, but are
460        not included in the return count.
461    
462    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
463        compiled something random. Now it gives a compile-time error (as does
464        Perl).
465    
466    32. A *MARK encountered during the processing of a positive assertion is now
467        recorded and passed back (compatible with Perl).
468    
469    33. If --only-matching or --colour was set on a pcregrep call whose pattern
470        had alternative anchored branches, the search for a second match in a line
471        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
472        matched the line "0102" twice. The same bug affected patterns that started
473        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
474        twice.
475    
476    34. Previously, PCRE did not allow quantification of assertions. However, Perl
477        does, and because of capturing effects, quantifying parenthesized
478        assertions may at times be useful. Quantifiers are now allowed for
479        parenthesized assertions.
480    
481    35. A minor code tidy in pcre_compile() when checking options for \R usage.
482    
483    36. \g was being checked for fancy things in a character class, when it should
484        just be a literal "g".
485    
486    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
487        appearance of a nested POSIX class supersedes an apparent external class.
488        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
489        unescaped square brackets may also appear as part of class names. For
490        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
491        more like Perl. (But see 8.20/1 above.)
492    
493    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
494        was because it thought it was \N{name}, which is not supported).
495    
496    39. Add minix to OS list not supporting the -S option in pcretest.
497    
498    40. PCRE tries to detect cases of infinite recursion at compile time, but it
499        cannot analyze patterns in sufficient detail to catch mutual recursions
500        such as ((?1))((?2)). There is now a runtime test that gives an error if a
501        subgroup is called recursively as a subpattern for a second time at the
502        same position in the subject string. In previous releases this might have
503        been caught by the recursion limit, or it might have run out of stack.
504    
505    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
506        happen only once. PCRE was, however incorrectly giving a compile time error
507        "recursive call could loop indefinitely" because it cannot analyze the
508        pattern in sufficient detail. The compile time test no longer happens when
509        PCRE is compiling a conditional subpattern, but actual runaway loops are
510        now caught at runtime (see 40 above).
511    
512    42. It seems that Perl allows any characters other than a closing parenthesis
513        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
514        has been changed to be the same.
515    
516    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
517        as not to get warnings when autogen.sh is called. Also changed
518        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
519    
520    44. To help people who use pcregrep to scan files containing exceedingly long
521        lines, the following changes have been made:
522    
523        (a) The default value of the buffer size parameter has been increased from
524            8K to 20K. (The actual buffer used is three times this size.)
525    
526        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
527            PCRE is built.
528    
529        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
530            to be set at run time.
531    
532        (d) Numerical values in pcregrep options can be followed by K or M, for
533            example --buffer-size=50K.
534    
535        (e) If a line being scanned overflows pcregrep's buffer, an error is now
536            given and the return code is set to 2.
537    
538    45. Add a pointer to the latest mark to the callout data block.
539    
540    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
541        partial match of an empty string instead of no match. This was specific to
542        the use of ".".
543    
544    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
545        complete match instead of a partial match. This bug was dependent on both
546        the PCRE_UTF8 and PCRE_DOTALL options being set.
547    
548    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
549        starting byte set, because \b was not being ignored.
550    
551    
552    Version 8.12 15-Jan-2011
553    ------------------------
554    
555    1.  Fixed some typos in the markup of the man pages, and wrote a script that
556        checks for such things as part of the documentation building process.
557    
558    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
559        --match-limit and --recursion-limit options (added for 8.11). In
560        particular, this made one of the standard tests fail. (The integer value
561        went into the wrong half of a long int.)
562    
563    3.  If the --colour option was given to pcregrep with -v (invert match), it
564        did strange things, either producing crazy output, or crashing. It should,
565        of course, ignore a request for colour when reporting lines that do not
566        match.
567    
568    4.  Another pcregrep bug caused similar problems if --colour was specified with
569        -M (multiline) and the pattern match finished with a line ending.
570    
571    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
572        matched in multiline mode, the following line was shown as part of the
573        match. This seems wrong, so I have changed it.
574    
575    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
576        the check for further matches in the same line (so they could be coloured)
577        to overrun the end of the current line. If another match was found, it was
578        incorrectly shown (and then shown again when found in the next line).
579    
580    7.  If pcregrep was compiled under Windows, there was a reference to the
581        function pcregrep_exit() before it was defined. I am assuming this was
582        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
583        reported by a user. I've moved the definition above the reference.
584    
585    
586    Version 8.11 10-Dec-2010
587    ------------------------
588    
589    1.  (*THEN) was not working properly if there were untried alternatives prior
590        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
591        backtracked to try for "b" instead of moving to the next alternative branch
592        at the same level (in this case, to look for "c"). The Perl documentation
593        is clear that when (*THEN) is backtracked onto, it goes to the "next
594        alternative in the innermost enclosing group".
595    
596    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
597        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
598        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
599        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
600        (*THEN).
601    
602    3.  If \s appeared in a character class, it removed the VT character from
603        the class, even if it had been included by some previous item, for example
604        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
605        of \s, but is part of the POSIX "space" class.)
606    
607    4.  A partial match never returns an empty string (because you can always
608        match an empty string at the end of the subject); however the checking for
609        an empty string was starting at the "start of match" point. This has been
610        changed to the "earliest inspected character" point, because the returned
611        data for a partial match starts at this character. This means that, for
612        example, /(?<=abc)def/ gives a partial match for the subject "abc"
613        (previously it gave "no match").
614    
615    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
616        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
617        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
618        has an implication that the given string is incomplete (because a partial
619        match is preferred over a full match). For this reason, these items now
620        give a partial match in this situation. [Aside: previously, the one case
621        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
622        match rather than a full match, which was wrong by the old rules, but is
623        now correct.]
624    
625    6.  There was a bug in the handling of #-introduced comments, recognized when
626        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
627        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
628        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
629        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
630        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
631        places in pcre_compile().
632    
633    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
634        comments when looking ahead for named forward references to subpatterns,
635        the only newline sequence it recognized was NL. It now handles newlines
636        according to the set newline convention.
637    
638    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
639        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
640        cater for a lack of strerror(). These oversights have been fixed.
641    
642    9.  Added --match-limit and --recursion-limit to pcregrep.
643    
644    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
645    
646    11. When the -o option was used, pcregrep was setting a return code of 1, even
647        when matches were found, and --line-buffered was not being honoured.
648    
649    12. Added an optional parentheses number to the -o and --only-matching options
650        of pcregrep.
651    
652    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
653        can match an empty string. The code to do it in pcretest and pcredemo
654        needed fixing:
655    
656        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
657            only one byte after an empty string match just before CRLF (this case
658            just got forgotten; "any" and "anycrlf" were OK).
659    
660        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
661            mode when an empty string match preceded an ASCII character followed by
662            a non-ASCII character. (The code for advancing by one character rather
663            than one byte was nonsense.)
664    
665        (c) The pcredemo.c sample program did not have any code at all to handle
666            the cases when CRLF is a valid newline sequence.
667    
668    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
669        as a starting offset was within the subject string. There is now a new
670        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
671        negative or greater than the length of the string. In order to test this,
672        pcretest is extended to allow the setting of negative starting offsets.
673    
674    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
675        starting offset points to the beginning of a UTF-8 character was
676        unnecessarily clumsy. I tidied it up.
677    
678    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
679        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
680    
681    17. Nobody had reported that the --include_dir option, which was added in
682        release 7.7 should have been called --include-dir (hyphen, not underscore)
683        for compatibility with GNU grep. I have changed it to --include-dir, but
684        left --include_dir as an undocumented synonym, and the same for
685        --exclude-dir, though that is not available in GNU grep, at least as of
686        release 2.5.4.
687    
688    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
689        characters from a string of bytes) have been redefined so as not to use
690        loops, in order to improve performance in some environments. At the same
691        time, I abstracted some of the common code into auxiliary macros to save
692        repetition (this should not affect the compiled code).
693    
694    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
695        compile-time error is now given if \c is not followed by an ASCII
696        character, that is, a byte less than 128. (In EBCDIC mode, the code is
697        different, and any byte value is allowed.)
698    
699    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
700        START_OPTIMIZE option, which is now allowed at compile time - but just
701        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
702        to pcregrep and other applications that have no direct access to PCRE
703        options. The new /Y option in pcretest sets this option when calling
704        pcre_compile().
705    
706    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
707        back references. Groups containing recursive back references were forced to
708        be atomic by that change, but in the case of named groups, the amount of
709        memory required was incorrectly computed, leading to "Failed: internal
710        error: code overflow". This has been fixed.
711    
712    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
713        pcretest.c, to avoid build problems in some Borland environments.
714    
715    
716    Version 8.10 25-Jun-2010
717    ------------------------
718    
719    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
720        THEN.
721    
722    2.  (*ACCEPT) was not working when inside an atomic group.
723    
724    3.  Inside a character class, \B is treated as a literal by default, but
725        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
726        causes the error). The code is unchanged, but I tidied the documentation.
727    
728    4.  Inside a character class, PCRE always treated \R and \X as literals,
729        whereas Perl faults them if its -w option is set. I have changed PCRE so
730        that it faults them when PCRE_EXTRA is set.
731    
732    5.  Added support for \N, which always matches any character other than
733        newline. (It is the same as "." when PCRE_DOTALL is not set.)
734    
735    6.  When compiling pcregrep with newer versions of gcc which may have
736        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
737        declared with attribute warn_unused_result" were given. Just casting the
738        result to (void) does not stop the warnings; a more elaborate fudge is
739        needed. I've used a macro to implement this.
740    
741    7.  Minor change to pcretest.c to avoid a compiler warning.
742    
743    8.  Added four artifical Unicode properties to help with an option to make
744        \s etc use properties (see next item). The new properties are: Xan
745        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
746    
747    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
748        use Unicode properties. (*UCP) at the start of a pattern can be used to set
749        this option. Modified pcretest to add /W to test this facility. Added
750        REG_UCP to make it available via the POSIX interface.
751    
752    10. Added --line-buffered to pcregrep.
753    
754    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
755        studied, and the match started with a letter with a code point greater than
756        127 whose first byte was different to the first byte of the other case of
757        the letter, the other case of this starting letter was not recognized
758        (#976).
759    
760    12. If a pattern that was studied started with a repeated Unicode property
761        test, for example, \p{Nd}+, there was the theoretical possibility of
762        setting up an incorrect bitmap of starting bytes, but fortunately it could
763        not have actually happened in practice until change 8 above was made (it
764        added property types that matched character-matching opcodes).
765    
766    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
767        possible starting bytes for non-anchored patterns.
768    
769    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
770        \R, and also a number of cases that involve Unicode properties, both
771        explicit and implicit when PCRE_UCP is set.
772    
773    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
774        input, it could crash or give wrong results if characters with values
775        greater than 0xc0 were present in the subject string. (Detail: it assumed
776        UTF-8 input when processing these items.)
777    
778    16. Added a lot of (int) casts to avoid compiler warnings in systems where
779        size_t is 64-bit (#991).
780    
781    17. Added a check for running out of memory when PCRE is compiled with
782        --disable-stack-for-recursion (#990).
783    
784    18. If the last data line in a file for pcretest does not have a newline on
785        the end, a newline was missing in the output.
786    
787    19. The default pcre_chartables.c file recognizes only ASCII characters (values
788        less than 128) in its various bitmaps. However, there is a facility for
789        generating tables according to the current locale when PCRE is compiled. It
790        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
791        characters, are recognized by isspace() and therefore were getting set in
792        these tables, and indeed these tables seem to approximate to ISO 8859. This
793        caused a problem in UTF-8 mode when pcre_study() was used to create a list
794        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
795        which of course cannot start UTF-8 characters. I have changed the code so
796        that only real ASCII characters (less than 128) and the correct starting
797        bytes for UTF-8 encodings are set for characters greater than 127 when in
798        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
799        altogether.)
800    
801    20. Added the /T option to pcretest so as to be able to run tests with non-
802        standard character tables, thus making it possible to include the tests
803        used for 19 above in the standard set of tests.
804    
805    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
806        reference to a subpattern the other side of a comment that contains an
807        opening parenthesis caused either an internal compiling error, or a
808        reference to the wrong subpattern.
809    
810    
811    Version 8.02 19-Mar-2010
812  ------------------------  ------------------------
813    
814  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.
815    
816    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
817        configured.
818    
819    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
820        original author of that file, following a query about its status.
821    
822    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
823        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
824    
825    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
826        quantifier applied to a forward-referencing subroutine call, could compile
827        incorrect code or give the error "internal error: previously-checked
828        referenced subpattern not found".
829    
830    6.  Both MS Visual Studio and Symbian OS have problems with initializing
831        variables to point to external functions. For these systems, therefore,
832        pcre_malloc etc. are now initialized to local functions that call the
833        relevant global functions.
834    
835    7.  There were two entries missing in the vectors called coptable and poptable
836        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
837        I've fixed the data, and added a kludgy way of testing at compile time that
838        the lengths are correct (equal to the number of opcodes).
839    
840    8.  Following on from 7, I added a similar kludge to check the length of the
841        eint vector in pcreposix.c.
842    
843    9.  Error texts for pcre_compile() are held as one long string to avoid too
844        much relocation at load time. To find a text, the string is searched,
845        counting zeros. There was no check for running off the end of the string,
846        which could happen if a new error number was added without updating the
847        string.
848    
849    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
850    
851    11. \K was not working if it appeared in an atomic group or in a group that
852        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
853        \K is "not well defined" if used in an assertion. PCRE now accepts it if
854        the assertion is positive, but not if it is negative.
855    
856    12. Change 11 fortuitously reduced the size of the stack frame used in the
857        "match()" function of pcre_exec.c by one pointer. Forthcoming
858        implementation of support for (*MARK) will need an extra pointer on the
859        stack; I have reserved it now, so that the stack frame size does not
860        decrease.
861    
862    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
863        item in branch that calls a recursion is a subroutine call - as in the
864        second branch in the above example - was incorrectly given the compile-
865        time error "recursive call could loop indefinitely" because pcre_compile()
866        was not correctly checking the subroutine for matching a non-empty string.
867    
868    14. The checks for overrunning compiling workspace could trigger after an
869        overrun had occurred. This is a "should never occur" error, but it can be
870        triggered by pathological patterns such as hundreds of nested parentheses.
871        The checks now trigger 100 bytes before the end of the workspace.
872    
873    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
874    
875    
876  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
877  ------------------------  ------------------------

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