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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.8 25-Aug-08  Version 8.31
5    -----------------------------
7    1.  Fixing a wrong JIT test case and some compiler warnings.
9    2.  Removed a bashism from the RunTest script.
12    Version 8.30 04-February-2012
13    -----------------------------
15    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
16        name is defined in ctype.h.
18    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
19        only in quite long subpatterns.
21    3.  Removed the function pcre_info(), which has been obsolete and deprecated
22        since it was replaced by pcre_fullinfo() in February 2000.
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.
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.
34    6.  Add support for 16-bit character strings (a large amount of work involving
35        many changes and refactorings).
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.
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).
44    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
45        if they appear, or are escaped, in patterns.
47    10. Get rid of a number of -Wunused-but-set-variable warnings.
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.
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.
60    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
61        -lreadline.
63    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
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.
69    16. Experimental code added to "pcretest -C" to output the stack frame size.
72    Version 8.21 12-Dec-2011
73    ------------------------
75    1.  Updating the JIT compiler.
77    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
78        are added as well.
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.
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.
88    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
89        ECMA-262 standard.
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.
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.
105    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
106        being incorrectly compiled and would have given unpredicatble results.
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.
113    10. Add a cast and remove a redundant test from the code.
115    11. JIT should use pcre_malloc/pcre_free for allocation.
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).
121    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
123    14. Perl does not support \N without a following name in a [] class; PCRE now
124        also gives an error.
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.
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.
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.
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.
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+.
158    21. Retrieve executable code size support for the JIT compiler and fixing
159        some warnings.
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.
165    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
166        systems.
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.
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.
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.
180    27. Updated RunTest.bat as provided by Sheri Pierce.
182    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
184    29. Computation of memory usage for the table of capturing group names was
185        giving an unnecessarily large value.
188    Version 8.20 21-Oct-2011
189    ------------------------
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.
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.
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.
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.
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.
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.
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.
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.]
241    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
242        Sheri Pierce.
244    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
245        the first byte in a match must be "a".
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.
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.
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.
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.]
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 :-).
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.
279    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
280        RunGrepTest script failed.
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.
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.)
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.
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().
303    Version 8.13 16-Aug-2011
304    ------------------------
306    1.  The Unicode data tables have been updated to Unicode 6.0.0.
308    2.  Two minor typos in pcre_internal.h have been fixed.
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).
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).
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.
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().
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.
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.
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.
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().
359    11. While implementing 10, a number of bugs in the handling of groups were
360        discovered and fixed:
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.
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.
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.
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).
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.
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.
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.]
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.
406    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
407        was incorrectly computed.
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.
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.
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.
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.
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.
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.
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.
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.
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.
455    29. Some minor code refactoring concerning Unicode properties and scripts
456        should reduce the stack requirement of match() slightly.
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.
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).
466    32. A *MARK encountered during the processing of a positive assertion is now
467        recorded and passed back (compatible with Perl).
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.
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.
481    35. A minor code tidy in pcre_compile() when checking options for \R usage.
483    36. \g was being checked for fancy things in a character class, when it should
484        just be a literal "g".
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.)
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).
496    39. Add minix to OS list not supporting the -S option in pcretest.
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.
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).
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.
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).
520    44. To help people who use pcregrep to scan files containing exceedingly long
521        lines, the following changes have been made:
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.)
526        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
527            PCRE is built.
529        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
530            to be set at run time.
532        (d) Numerical values in pcregrep options can be followed by K or M, for
533            example --buffer-size=50K.
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.
538    45. Add a pointer to the latest mark to the callout data block.
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 ".".
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.
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.
552    Version 8.12 15-Jan-2011
553    ------------------------
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.
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.)
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.
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.
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.
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).
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.
586    Version 8.11 10-Dec-2010
587    ------------------------
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".
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).
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.)
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").
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.]
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().
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.
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.
642    9.  Added --match-limit and --recursion-limit to pcregrep.
644    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
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.
649    12. Added an optional parentheses number to the -o and --only-matching options
650        of pcregrep.
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:
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).
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.)
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.
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.
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.
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.
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.
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).
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.)
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().
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.
712    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
713        pcretest.c, to avoid build problems in some Borland environments.
716    Version 8.10 25-Jun-2010
717    ------------------------
719    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
720        THEN.
722    2.  (*ACCEPT) was not working when inside an atomic group.
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.
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.
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.)
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.
741    7.  Minor change to pcretest.c to avoid a compiler warning.
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).
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.
752    10. Added --line-buffered to pcregrep.
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).
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).
766    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
767        possible starting bytes for non-anchored patterns.
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.
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.)
778    16. Added a lot of (int) casts to avoid compiler warnings in systems where
779        size_t is 64-bit (#991).
781    17. Added a check for running out of memory when PCRE is compiled with
782        --disable-stack-for-recursion (#990).
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.
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.)
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.
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.
811    Version 8.02 19-Mar-2010
812    ------------------------
814    1.  The Unicode data tables have been updated to Unicode 5.2.0.
816    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
817        configured.
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.
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.
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".
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.
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).
840    8.  Following on from 7, I added a similar kludge to check the length of the
841        eint vector in pcreposix.c.
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.
849    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
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.
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.
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.
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.
873    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
876    Version 8.01 19-Jan-2010
877    ------------------------
879    1.  If a pattern contained a conditional subpattern with only one branch (in
880        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
881        computed the wrong minimum data length (which is of course zero for such
882        subpatterns). This could cause incorrect "no match" results.
884    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
885        the pattern is reset in the first branch, pcre_compile() failed with
886        "internal error: code overflow at offset...". This happened only when
887        the reset was to the original external option setting. (An optimization
888        abstracts leading options settings into an external setting, which was the
889        cause of this.)
891    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
892        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
893        assertion pattern did not match (meaning that the assertion was true), it
894        was incorrectly treated as false if the SKIP had been reached during the
895        matching. This also applied to assertions used as conditions.
897    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
898        assertion subpattern, including such a pattern used as a condition,
899        unpredictable results occurred, instead of the error return
902    5.  The C++ GlobalReplace function was not working like Perl for the special
903        situation when an empty string is matched. It now does the fancy magic
904        stuff that is necessary.
906    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
907        removed. (These were left over from very, very early versions of PCRE.)
909    7.  Some cosmetic changes to the code to make life easier when compiling it
910        as part of something else:
912        (a) Change DEBUG to PCRE_DEBUG.
914        (b) In pcre_compile(), rename the member of the "branch_chain" structure
915            called "current" as "current_branch", to prevent a collision with the
916            Linux macro when compiled as a kernel module.
918        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
919            prevent a collision with the Linux macro when compiled as a kernel
920            module.
922    8.  In pcre_compile() there are some checks for integer overflows that used to
923        cast potentially large values to (double). This has been changed to that
924        when building, a check for int64_t is made, and if it is found, it is used
925        instead, thus avoiding the use of floating point arithmetic. (There is no
926        other use of FP in PCRE.) If int64_t is not found, the fallback is to
927        double.
929    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
930        2005 (difference between two addresses compared to an unsigned value).
932    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
933        custom one, because of the following reported problem in Windows:
935          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
936              under Win32.
937          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
938              therefore missing the function definition.
939          - The compiler thus generates a "C" signature for the test function.
940          - The linker fails to find the "C" function.
941          - PCRE fails to configure if asked to do so against libbz2.
943    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
944        messages were output:
946          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
947          rerunning libtoolize, to keep the correct libtool macros in-tree.
948          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
950        I have done both of these things.
952    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
953        most of the time, it *can* run out if it is given a pattern that contains a
954        runaway infinite recursion. I updated the discussion in the pcrestack man
955        page.
957    13. Now that we have gone to the x.xx style of version numbers, the minor
958        version may start with zero. Using 08 or 09 is a bad idea because users
959        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
960        interpreted as invalid octal numbers. I've updated the previous comment in
961        configure.ac, and also added a check that gives an error if 08 or 09 are
962        used.
964    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
965        causing partial matching to fail when the end of the subject matched \W
966        in a UTF-8 pattern where \W was quantified with a minimum of 3.
968    15. There were some discrepancies between the declarations in pcre_internal.h
969        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
970        their definitions. The declarations used "const uschar *" and the
971        definitions used USPTR. Even though USPTR is normally defined as "const
972        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
973        reported that: "This difference in casting confuses some C++ compilers, for
974        example, SunCC recognizes above declarations as different functions and
975        generates broken code for hbpcre." I have changed the declarations to use
976        USPTR.
978    16. GNU libtool is named differently on some systems. The autogen.sh script now
979        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
980        (FreeBSD).
982    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
983        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
984        comment: "Figure out how to create a longlong from a string: strtoll and
985        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
986        instance, but it only takes 2 args instead of 3!"
988    18. A subtle bug concerned with back references has been fixed by a change of
989        specification, with a corresponding code fix. A pattern such as
990        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
991        refers, was giving matches when it shouldn't. For example, xa=xaaa would
992        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
993        same bug. Such groups have to be quantified to be useful, or contained
994        inside another quantified group. (If there's no repetition, the reference
995        can never match.) The problem arises because, having left the group and
996        moved on to the rest of the pattern, a later failure that backtracks into
997        the group uses the captured value from the final iteration of the group
998        rather than the correct earlier one. I have fixed this in PCRE by forcing
999        any group that contains a reference to itself to be an atomic group; that
1000        is, there cannot be any backtracking into it once it has completed. This is
1001        similar to recursive and subroutine calls.
1004    Version 8.00 19-Oct-09
1005    ----------------------
1007    1.  The table for translating pcre_compile() error codes into POSIX error codes
1008        was out-of-date, and there was no check on the pcre_compile() error code
1009        being within the table. This could lead to an OK return being given in
1010        error.
1012    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
1013        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1014        in a Windows environment.
1016    3.  The pcregrep --count option prints the count for each file even when it is
1017        zero, as does GNU grep. However, pcregrep was also printing all files when
1018        --files-with-matches was added. Now, when both options are given, it prints
1019        counts only for those files that have at least one match. (GNU grep just
1020        prints the file name in this circumstance, but including the count seems
1021        more useful - otherwise, why use --count?) Also ensured that the
1022        combination -clh just lists non-zero counts, with no names.
1024    4.  The long form of the pcregrep -F option was incorrectly implemented as
1025        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1026        but it seems right to fix it, and I didn't think it was worth preserving
1027        the old behaviour.
1029    5.  The command line items --regex=pattern and --regexp=pattern were not
1030        recognized by pcregrep, which required --regex pattern or --regexp pattern
1031        (with a space rather than an '='). The man page documented the '=' forms,
1032        which are compatible with GNU grep; these now work.
1034    6.  No libpcreposix.pc file was created for pkg-config; there was just
1035        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1037    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1038        when UCP support is not needed, by modifying the Python script that
1039        generates it from Unicode data files. This should not matter if the module
1040        is correctly used as a library, but I received one complaint about 50K of
1041        unwanted data. My guess is that the person linked everything into his
1042        program rather than using a library. Anyway, it does no harm.
1044    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1045        was a minimum greater than 1 for a wide character in a possessive
1046        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1047        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1048        character. Chaos in the form of incorrect output or a compiling loop could
1049        result.
1051    9.  The restrictions on what a pattern can contain when partial matching is
1052        requested for pcre_exec() have been removed. All patterns can now be
1053        partially matched by this function. In addition, if there are at least two
1054        slots in the offset vector, the offset of the earliest inspected character
1055        for the match and the offset of the end of the subject are set in them when
1056        PCRE_ERROR_PARTIAL is returned.
1058    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1059        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1060        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1061        and may be more useful for multi-segment matching.
1063    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1064        used to be given if ever the end of the subject was reached; now it is
1065        given only if matching could not proceed because another character was
1066        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1067        string "Z", which now yields "no match" instead of "partial match". In the
1068        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1069        final character ended with (*FAIL).
1071    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1072        if the pattern had a "must contain" character that was already found in the
1073        earlier partial match, unless partial matching was again requested. For
1074        example, with the pattern /dog.(body)?/, the "must contain" character is
1075        "g". If the first part-match was for the string "dog", restarting with
1076        "sbody" failed. This bug has been fixed.
1078    13. The string returned by pcre_dfa_exec() after a partial match has been
1079        changed so that it starts at the first inspected character rather than the
1080        first character of the match. This makes a difference only if the pattern
1081        starts with a lookbehind assertion or \b or \B (\K is not supported by
1082        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1083        matching functions compatible, and I think it's the right thing to do.
1085    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1086        so that the demonstration program is easily available in environments where
1087        PCRE has not been installed from source.
1089    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1090        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1091        library.
1093    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1094        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1095        is not the first non-POSIX option to be added. Clearly some people find
1096        these options useful.
1098    17. If a caller to the POSIX matching function regexec() passes a non-zero
1099        value for nmatch with a NULL value for pmatch, the value of
1100        nmatch is forced to zero.
1102    18. RunGrepTest did not have a test for the availability of the -u option of
1103        the diff command, as RunTest does. It now checks in the same way as
1104        RunTest, and also checks for the -b option.
1106    19. If an odd number of negated classes containing just a single character
1107        interposed, within parentheses, between a forward reference to a named
1108        subpattern and the definition of the subpattern, compilation crashed with
1109        an internal error, complaining that it could not find the referenced
1110        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1111        [The bug was that it was starting one character too far in when skipping
1112        over the character class, thus treating the ] as data rather than
1113        terminating the class. This meant it could skip too much.]
1115    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1116        /g option in pcretest when the pattern contains \K, which makes it possible
1117        to have an empty string match not at the start, even when the pattern is
1118        anchored. Updated pcretest and pcredemo to use this option.
1120    21. If the maximum number of capturing subpatterns in a recursion was greater
1121        than the maximum at the outer level, the higher number was returned, but
1122        with unset values at the outer level. The correct (outer level) value is
1123        now given.
1125    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1126        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1127        make it do so. The string so far is captured, making this feature
1128        compatible with Perl.
1130    23. The tests have been re-organized, adding tests 11 and 12, to make it
1131        possible to check the Perl 5.10 features against Perl 5.10.
1133    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1134        pattern matches a fixed length string. PCRE did not allow this; now it
1135        does. Neither allows recursion.
1137    25. I finally figured out how to implement a request to provide the minimum
1138        length of subject string that was needed in order to match a given pattern.
1139        (It was back references and recursion that I had previously got hung up
1140        on.) This code has now been added to pcre_study(); it finds a lower bound
1141        to the length of subject needed. It is not necessarily the greatest lower
1142        bound, but using it to avoid searching strings that are too short does give
1143        some useful speed-ups. The value is available to calling programs via
1144        pcre_fullinfo().
1146    26. While implementing 25, I discovered to my embarrassment that pcretest had
1147        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1148        study optimizations had never been tested with that matching function.
1149        Oops. What is worse, even when it was passed study data, there was a bug in
1150        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1151        were also very few tests of studied patterns with pcre_dfa_exec().
1153    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1154        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1155        on the other side of the coin, they are no longer allowed to have different
1156        names, because these cannot be distinguished in PCRE, and this has caused
1157        confusion. (This is a difference from Perl.)
1159    28. When duplicate subpattern names are present (necessarily with different
1160        numbers, as required by 27 above), and a test is made by name in a
1161        conditional pattern, either for a subpattern having been matched, or for
1162        recursion in such a pattern, all the associated numbered subpatterns are
1163        tested, and the overall condition is true if the condition is true for any
1164        one of them. This is the way Perl works, and is also more like the way
1165        testing by number works.
1168    Version 7.9 11-Apr-09
1169    ---------------------
1171    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1172        (pcretest), all targets were linked against these libraries. This included
1173        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1174        libraries. This caused unwanted dependencies to be created. This problem
1175        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1176        pcretest is linked with readline.
1178    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1179        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1180        moved outside it again, because FALSE and TRUE are already defined in AIX,
1181        but BOOL is not.
1183    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1184        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1186    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1187        hyphens) following file names and line numbers when outputting matching
1188        lines. This is not true; no spaces are inserted. I have also clarified the
1189        wording for the --colour (or --color) option.
1191    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1192        was not coloured; this is different to GNU grep, so I have changed it to be
1193        the same.
1195    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1196        each matching line was coloured. Now it goes on to look for further matches
1197        of any of the test patterns, which is the same behaviour as GNU grep.
1199    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1200        doesn't make sense to accept an empty string match in pcregrep, so I have
1201        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1202        seems to be how GNU grep behaves.
1204    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1205        start or after a newline", because the conditional assertion was not being
1206        correctly handled. The rule now is that both the assertion and what follows
1207        in the first alternative must satisfy the test.
1209    9.  If auto-callout was enabled in a pattern with a conditional group whose
1210        condition was an assertion, PCRE could crash during matching, both with
1211        pcre_exec() and pcre_dfa_exec().
1213    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1214        used for matching.
1216    11. Unicode property support in character classes was not working for
1217        characters (bytes) greater than 127 when not in UTF-8 mode.
1219    12. Added the -M command line option to pcretest.
1221    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1223    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1225    16. Added comments and documentation about mis-use of no_arg in the C++
1226        wrapper.
1228    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1229        from Martin Jerabek that uses macro names for all relevant character and
1230        string constants.
1232    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1233        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1234        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1235        these, but not everybody uses configure.
1237    19. A conditional group that had only one branch was not being correctly
1238        recognized as an item that could match an empty string. This meant that an
1239        enclosing group might also not be so recognized, causing infinite looping
1240        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1241        with the subject "ab", where knowledge that the repeated group can match
1242        nothing is needed in order to break the loop.
1244    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1245        exec(), but without supplying a callout function, matching went wrong.
1247    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1248        leak if the size of the offset vector was greater than 30. When the vector
1249        is smaller, the saved offsets during recursion go onto a local stack
1250        vector, but for larger vectors malloc() is used. It was failing to free
1251        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1252        error, in fact).
1254    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1255        heapframe that is used only when UTF-8 support is enabled. This caused no
1256        problem, but was untidy.
1258    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1259        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1260        included within another project.
1262    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1263        slightly modified by me:
1265          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1266              not building pcregrep.
1268          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1269              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1271    25. Forward references, both numeric and by name, in patterns that made use of
1272        duplicate group numbers, could behave incorrectly or give incorrect errors,
1273        because when scanning forward to find the reference group, PCRE was not
1274        taking into account the duplicate group numbers. A pattern such as
1275        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1277    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1278        the feature of a custom pointer more persuasive (as requested by a user).
1280    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1281        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1282        pre-defined.
1284    28. Added support for (*UTF8) at the start of a pattern.
1286    29. Arrange for flags added by the "release type" setting in CMake to be shown
1287        in the configuration summary.
1290    Version 7.8 05-Sep-08
1291  ---------------------  ---------------------
1293  1.  Replaced UCP searching code with optimized version as implemented for Ad  1.  Replaced UCP searching code with optimized version as implemented for Ad
# Line 31  Version 7.8 25-Aug-08 Line 1317  Version 7.8 25-Aug-08
1318  7.  Added two (int) casts to pcregrep when printing the difference of two  7.  Added two (int) casts to pcregrep when printing the difference of two
1319      pointers, in case they are 64-bit values.      pointers, in case they are 64-bit values.
1321  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1322      test 2 if it fails.      test 2 if it fails.
1324  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1325      and a #define of that name to empty if it is not externally set. This is to      and a #define of that name to empty if it is not externally set. This is to
1326      allow users of MSVC to set it if necessary.      allow users of MSVC to set it if necessary.
1328  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1329      the convenience functions in the pcre_get.c source file.      the convenience functions in the pcre_get.c source file.
1331  11. An option change at the start of a pattern that had top-level alternatives  11. An option change at the start of a pattern that had top-level alternatives
1332      could cause overwriting and/or a crash. This command provoked a crash in      could cause overwriting and/or a crash. This command provoked a crash in
1333      some environments:      some environments:
1335        printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest        printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1337      This potential security problem was recorded as CVE-2008-2371.      This potential security problem was recorded as CVE-2008-2371.
1339  12. For a pattern where the match had to start at the beginning or immediately  12. For a pattern where the match had to start at the beginning or immediately
1340      after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and      after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1341      pcre_dfa_exec() could read past the end of the passed subject if there was      pcre_dfa_exec() could read past the end of the passed subject if there was
1342      no match. To help with detecting such bugs (e.g. with valgrind), I modified      no match. To help with detecting such bugs (e.g. with valgrind), I modified
1343      pcretest so that it places the subject at the end of its malloc-ed buffer.      pcretest so that it places the subject at the end of its malloc-ed buffer.
1345  13. The change to pcretest in 12 above threw up a couple more cases when pcre_  13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1346      exec() might read past the end of the data buffer in UTF-8 mode.      exec() might read past the end of the data buffer in UTF-8 mode.
1348  14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and  14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1349      the data contained the byte 0x85 as part of a UTF-8 character within its      the data contained the byte 0x85 as part of a UTF-8 character within its
1350      first line. This applied both to normal and DFA matching.      first line. This applied both to normal and DFA matching.
1352  15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,  15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1353      /^[^d]*?$/8 failed to match "abc".      /^[^d]*?$/8 failed to match "abc".
1355  16. Added a missing copyright notice to pcrecpp_internal.h.  16. Added a missing copyright notice to pcrecpp_internal.h.
1357  17. Make it more clear in the documentation that values returned from  17. Make it more clear in the documentation that values returned from
1358      pcre_exec() in ovector are byte offsets, not character counts.      pcre_exec() in ovector are byte offsets, not character counts.
1360    18. Tidied a few places to stop certain compilers from issuing warnings.
1362    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1363        supplied by Stefan Weber. I made a further small update for 7.8 because
1364        there is a change of source arrangements: the pcre_searchfuncs.c module is
1365        replaced by pcre_ucd.c.
1368  Version 7.7 07-May-08  Version 7.7 07-May-08
1369  ---------------------  ---------------------

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