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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.0 02 Jul-08  Version 8.30
5    ------------
6    
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
9    
10    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
11        only in quite long subpatterns.
12    
13    3.  Removed the function pcre_info(), which has been obsolete and deprecated
14        since it was replaced by pcre_fullinfo() in February 2000.
15    
16    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
17        match a (*MARK), and the match failed at the start of the subject, a
18        reference to memory before the start of the subject could occur. This bug
19        was introduced by fix 17 of release 8.21.
20    
21    5.  A reference to an unset group with zero minimum repetition was giving
22        totally wrong answers (in non-JavaScript-compatibility mode). For example,
23        /(another)?(\1?)test/ matched against "hello world test". This bug was
24        introduced in release 8.13.
25    
26    6.  Add support for 16-bit character strings (a large amount of work involving
27        many changes and refactorings).
28    
29    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
30        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
31        from a file.
32    
33    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
34        rounding is not applied in this particular case).
35    
36    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37        if they appear, or are escaped, in patterns.
38    
39    10. Get rid of a number of -Wunused-but-set-variable warnings.
40    
41    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44        also returns the mark "x". This bug applied to capturing parentheses,
45        non-capturing parentheses, and atomic parentheses. It also applied to some
46        assertions.
47    
48    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
49        information out of configure.ac instead of relying on pcre.h.generic, which
50        is not stored in the repository.
51    
52    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
53        -lreadline.
54    
55    
56    Version 8.21 12-Dec-2011
57    ------------------------
58    
59    1.  Updating the JIT compiler.
60    
61    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
62        are added as well.
63    
64    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
65        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
66        calling _pcre_jit_exec. Some extra comments are added.
67    
68    4.  (*MARK) settings inside atomic groups that do not contain any capturing
69        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
70        was introduced by change 18 for 8.20.
71    
72    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
73        ECMA-262 standard.
74    
75    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
76        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
77        This bug was probably introduced by change 9 of 8.13.
78    
79    7.  While fixing 6 above, I noticed that a number of other items were being
80        incorrectly rejected as "not fixed length". This arose partly because newer
81        opcodes had not been added to the fixed-length checking code. I have (a)
82        corrected the bug and added tests for these items, and (b) arranged for an
83        error to occur if an unknown opcode is encountered while checking for fixed
84        length instead of just assuming "not fixed length". The items that were
85        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
86        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
87        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
88    
89    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
90        being incorrectly compiled and would have given unpredicatble results.
91    
92    9.  A possessively repeated subpattern with minimum repeat count greater than
93        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
94        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
95        the first (A) could occur when it should not.
96    
97    10. Add a cast and remove a redundant test from the code.
98    
99    11. JIT should use pcre_malloc/pcre_free for allocation.
100    
101    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
102        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
103        is anything other than /usr, -L is still shown).
104    
105    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
106    
107    14. Perl does not support \N without a following name in a [] class; PCRE now
108        also gives an error.
109    
110    15. If a forward reference was repeated with an upper limit of around 2000,
111        it caused the error "internal error: overran compiling workspace". The
112        maximum number of forward references (including repeats) was limited by the
113        internal workspace, and dependent on the LINK_SIZE. The code has been
114        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
115        the default depends on LINK_SIZE. There is a new upper limit (for safety)
116        of around 200,000 forward references. While doing this, I also speeded up
117        the filling in of repeated forward references.
118    
119    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
120        incorrectly expecting the subject to contain another "a" after the start.
121    
122    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
123        in the match, the SKIP should be ignored. This was not happening; instead
124        the SKIP was being treated as NOMATCH. For patterns such as
125        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
126        tested.
127    
128    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
129        now much more compatible with Perl, in particular in cases where the result
130        is a non-match for a non-anchored pattern. For example, if
131        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
132        "m", where previously it did not return a name. A side effect of this
133        change is that for partial matches, the last encountered mark name is
134        returned, as for non matches. A number of tests that were previously not
135        Perl-compatible have been moved into the Perl-compatible test files. The
136        refactoring has had the pleasing side effect of removing one argument from
137        the match() function, thus reducing its stack requirements.
138    
139    19. If the /S+ option was used in pcretest to study a pattern using JIT,
140        subsequent uses of /S (without +) incorrectly behaved like /S+.
141    
142    21. Retrieve executable code size support for the JIT compiler and fixing
143        some warnings.
144    
145    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
146        not work when the shorter character appeared right at the end of the
147        subject string.
148    
149    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
150        systems.
151    
152    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
153        output it when the /M option is used in pcretest.
154    
155    25. The CheckMan script was not being included in the distribution. Also, added
156        an explicit "perl" to run Perl scripts from the PrepareRelease script
157        because this is reportedly needed in Windows.
158    
159    26. If study data was being save in a file and studying had not found a set of
160        "starts with" bytes for the pattern, the data written to the file (though
161        never used) was taken from uninitialized memory and so caused valgrind to
162        complain.
163    
164    27. Updated RunTest.bat as provided by Sheri Pierce.
165    
166    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
167    
168    29. Computation of memory usage for the table of capturing group names was
169        giving an unnecessarily large value.
170    
171    
172    Version 8.20 21-Oct-2011
173    ------------------------
174    
175    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
176        a POSIX class. After further experiments with Perl, which convinced me that
177        Perl has bugs and confusions, a closing square bracket is no longer allowed
178        in a POSIX name. This bug also affected patterns with classes that started
179        with full stops.
180    
181    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
182        captured substring, but while checking the failing first alternative,
183        substring 1 is temporarily captured. If the output vector supplied to
184        pcre_exec() was not big enough for this capture, the yield of the function
185        was still zero ("insufficient space for captured substrings"). This cannot
186        be totally fixed without adding another stack variable, which seems a lot
187        of expense for a edge case. However, I have improved the situation in cases
188        such as /(a)(b)x|abc/ matched against "abc", where the return code
189        indicates that fewer than the maximum number of slots in the ovector have
190        been set.
191    
192    3.  Related to (2) above: when there are more back references in a pattern than
193        slots in the output vector, pcre_exec() uses temporary memory during
194        matching, and copies in the captures as far as possible afterwards. It was
195        using the entire output vector, but this conflicts with the specification
196        that only 2/3 is used for passing back captured substrings. Now it uses
197        only the first 2/3, for compatibility. This is, of course, another edge
198        case.
199    
200    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
201        main code base, and can be used by building with --enable-jit. When this is
202        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
203        runtime --no-jit option is given.
204    
205    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
206        ovector, the return from the function was zero, implying that there were
207        other matches that did not fit. The correct "exactly full" value is now
208        returned.
209    
210    6.  If a subpattern that was called recursively or as a subroutine contained
211        (*PRUNE) or any other control that caused it to give a non-standard return,
212        invalid errors such as "Error -26 (nested recursion at the same subject
213        position)" or even infinite loops could occur.
214    
215    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
216        computing the minimum length on reaching *ACCEPT, and so ended up with the
217        wrong value of 1 rather than 0. Further investigation indicates that
218        computing a minimum subject length in the presence of *ACCEPT is difficult
219        (think back references, subroutine calls), and so I have changed the code
220        so that no minimum is registered for a pattern that contains *ACCEPT.
221    
222    8.  If (*THEN) was present in the first (true) branch of a conditional group,
223        it was not handled as intended. [But see 16 below.]
224    
225    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
226        Sheri Pierce.
227    
228    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
229        the first byte in a match must be "a".
230    
231    11. Change 17 for 8.13 increased the recursion depth for patterns like
232        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
233        pattern contains any instances of (*THEN). If it does not, the old
234        optimizations are restored. It would be nice to do this on a per-group
235        basis, but at the moment that is not feasible.
236    
237    12. In some environments, the output of pcretest -C is CRLF terminated. This
238        broke RunTest's code that checks for the link size. A single white space
239        character after the value is now allowed for.
240    
241    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
242        For "fr", it uses the Windows-specific input and output files.
243    
244    14. If (*THEN) appeared in a group that was called recursively or as a
245        subroutine, it did not work as intended. [But see next item.]
246    
247    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
248        pattern fragments (but not containing any | characters). If A and B are
249        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
250        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
251        D. In other words, Perl considers parentheses that do not contain any |
252        characters to be part of a surrounding alternative, whereas PCRE was
253        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
254        differently. PCRE now behaves in the same way as Perl, except in the case
255        of subroutine/recursion calls such as (?1) which have in any case always
256        been different (but PCRE had them first :-).
257    
258    16. Related to 15 above: Perl does not treat the | in a conditional group as
259        creating alternatives. Such a group is treated in the same way as an
260        ordinary group without any | characters when processing (*THEN). PCRE has
261        been changed to match Perl's behaviour.
262    
263    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
264        RunGrepTest script failed.
265    
266    18. Change 22 for version 13 caused atomic groups to use more stack. This is
267        inevitable for groups that contain captures, but it can lead to a lot of
268        stack use in large patterns. The old behaviour has been restored for atomic
269        groups that do not contain any capturing parentheses.
270    
271    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
272        suppress the check for a minimum subject length at run time. (If it was
273        given to pcre_exec() or pcre_dfa_exec() it did work.)
274    
275    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
276        fail to work when decoding hex characters in data strings in EBCDIC
277        environments.
278    
279    21. It appears that in at least one Mac OS environment, the isxdigit() function
280        is implemented as a macro that evaluates to its argument more than once,
281        contravening the C 90 Standard (I haven't checked a later standard). There
282        was an instance in pcretest which caused it to go wrong when processing
283        \x{...} escapes in subject strings. The has been rewritten to avoid using
284        things like p++ in the argument of isxdigit().
285    
286    
287    Version 8.13 16-Aug-2011
288    ------------------------
289    
290    1.  The Unicode data tables have been updated to Unicode 6.0.0.
291    
292    2.  Two minor typos in pcre_internal.h have been fixed.
293    
294    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
295        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
296        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
297    
298    4.  There were a number of related bugs in the code for matching backrefences
299        caselessly in UTF-8 mode when codes for the characters concerned were
300        different numbers of bytes. For example, U+023A and U+2C65 are an upper
301        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
302        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
303        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
304        2-byte code at the end of the subject (it thought there wasn't enough data
305        left).
306    
307    5.  Comprehensive information about what went wrong is now returned by
308        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
309        as the output vector has at least 2 elements. The offset of the start of
310        the failing character and a reason code are placed in the vector.
311    
312    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
313        now returned is for the first byte of the failing character, instead of the
314        last byte inspected. This is an incompatible change, but I hope it is small
315        enough not to be a problem. It makes the returned offset consistent with
316        pcre_exec() and pcre_dfa_exec().
317    
318    7.  pcretest now gives a text phrase as well as the error number when
319        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
320        failure, the offset and reason code are output.
321    
322    8.  When \R was used with a maximizing quantifier it failed to skip backwards
323        over a \r\n pair if the subsequent match failed. Instead, it just skipped
324        back over a single character (\n). This seems wrong (because it treated the
325        two characters as a single entity when going forwards), conflicts with the
326        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
327        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
328        has been changed.
329    
330    9.  Some internal refactoring has changed the processing so that the handling
331        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
332        time (the PCRE_DOTALL option was changed this way some time ago: version
333        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
334        which was always a bit of a fudge. It also means that there is one less
335        argument for the match() function, which reduces its stack requirements
336        slightly. This change also fixes an incompatibility with Perl: the pattern
337        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
338    
339    10. More internal refactoring has drastically reduced the number of recursive
340        calls to match() for possessively repeated groups such as (abc)++ when
341        using pcre_exec().
342    
343    11. While implementing 10, a number of bugs in the handling of groups were
344        discovered and fixed:
345    
346        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
347        (a|)*(?1) gave a compile-time internal error.
348        ((a|)+)+  did not notice that the outer group could match an empty string.
349        (^a|^)+   was not marked as anchored.
350        (.*a|.*)+ was not marked as matching at start or after a newline.
351    
352    12. Yet more internal refactoring has removed another argument from the match()
353        function. Special calls to this function are now indicated by setting a
354        value in a variable in the "match data" data block.
355    
356    13. Be more explicit in pcre_study() instead of relying on "default" for
357        opcodes that mean there is no starting character; this means that when new
358        ones are added and accidentally left out of pcre_study(), testing should
359        pick them up.
360    
361    14. The -s option of pcretest has been documented for ages as being an old
362        synonym of -m (show memory usage). I have changed it to mean "force study
363        for every regex", that is, assume /S for every regex. This is similar to -i
364        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
365        using it. It makes it easier to run collections of tests with and without
366        study enabled, and thereby test pcre_study() more easily. All the standard
367        tests are now run with and without -s (but some patterns can be marked as
368        "never study" - see 20 below).
369    
370    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
371        restoration of the capturing data to the outer values was not happening
372        correctly.
373    
374    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
375        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
376        pattern had matched an empty string, and so incorrectly returned a no
377        match.
378    
379    17. There was optimizing code for the last branch of non-capturing parentheses,
380        and also for the obeyed branch of a conditional subexpression, which used
381        tail recursion to cut down on stack usage. Unfortunately, now that there is
382        the possibility of (*THEN) occurring in these branches, tail recursion is
383        no longer possible because the return has to be checked for (*THEN). These
384        two optimizations have therefore been removed. [But see 8.20/11 above.]
385    
386    18. If a pattern containing \R was studied, it was assumed that \R always
387        matched two bytes, thus causing the minimum subject length to be
388        incorrectly computed because \R can also match just one byte.
389    
390    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
391        was incorrectly computed.
392    
393    20. If /S is present twice on a test pattern in pcretest input, it now
394        *disables* studying, thereby overriding the use of -s on the command line
395        (see 14 above). This is necessary for one or two tests to keep the output
396        identical in both cases.
397    
398    21. When (*ACCEPT) was used in an assertion that matched an empty string and
399        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
400    
401    22. When an atomic group that contained a capturing parenthesis was
402        successfully matched, but the branch in which it appeared failed, the
403        capturing was not being forgotten if a higher numbered group was later
404        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
405        group 1 to "a", when in fact it should be unset. This applied to multi-
406        branched capturing and non-capturing groups, repeated or not, and also to
407        positive assertions (capturing in negative assertions does not happen
408        in PCRE) and also to nested atomic groups.
409    
410    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
411        subject after a captured substring, to make it easier to tell which of a
412        number of identical substrings has been captured.
413    
414    24. The way atomic groups are processed by pcre_exec() has been changed so that
415        if they are repeated, backtracking one repetition now resets captured
416        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
417        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
418        "aaa". Previously, it would have been "a". As part of this code
419        refactoring, the way recursive calls are handled has also been changed.
420    
421    25. If an assertion condition captured any substrings, they were not passed
422        back unless some other capturing happened later. For example, if
423        (?(?=(a))a) was matched against "a", no capturing was returned.
424    
425    26. When studying a pattern that contained subroutine calls or assertions,
426        the code for finding the minimum length of a possible match was handling
427        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
428        group 1 called group 2 while simultaneously a separate group 2 called group
429        1). A stack overflow occurred in this case. I have fixed this by limiting
430        the recursion depth to 10.
431    
432    27. Updated RunTest.bat in the distribution to the version supplied by Tom
433        Fortmann. This supports explicit test numbers on the command line, and has
434        argument validation and error reporting.
435    
436    28. An instance of \X with an unlimited repeat could fail if at any point the
437        first character it looked at was a mark character.
438    
439    29. Some minor code refactoring concerning Unicode properties and scripts
440        should reduce the stack requirement of match() slightly.
441    
442    30. Added the '=' option to pcretest to check the setting of unused capturing
443        slots at the end of the pattern, which are documented as being -1, but are
444        not included in the return count.
445    
446    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
447        compiled something random. Now it gives a compile-time error (as does
448        Perl).
449    
450    32. A *MARK encountered during the processing of a positive assertion is now
451        recorded and passed back (compatible with Perl).
452    
453    33. If --only-matching or --colour was set on a pcregrep call whose pattern
454        had alternative anchored branches, the search for a second match in a line
455        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
456        matched the line "0102" twice. The same bug affected patterns that started
457        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
458        twice.
459    
460    34. Previously, PCRE did not allow quantification of assertions. However, Perl
461        does, and because of capturing effects, quantifying parenthesized
462        assertions may at times be useful. Quantifiers are now allowed for
463        parenthesized assertions.
464    
465    35. A minor code tidy in pcre_compile() when checking options for \R usage.
466    
467    36. \g was being checked for fancy things in a character class, when it should
468        just be a literal "g".
469    
470    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
471        appearance of a nested POSIX class supersedes an apparent external class.
472        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
473        unescaped square brackets may also appear as part of class names. For
474        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
475        more like Perl. (But see 8.20/1 above.)
476    
477    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
478        was because it thought it was \N{name}, which is not supported).
479    
480    39. Add minix to OS list not supporting the -S option in pcretest.
481    
482    40. PCRE tries to detect cases of infinite recursion at compile time, but it
483        cannot analyze patterns in sufficient detail to catch mutual recursions
484        such as ((?1))((?2)). There is now a runtime test that gives an error if a
485        subgroup is called recursively as a subpattern for a second time at the
486        same position in the subject string. In previous releases this might have
487        been caught by the recursion limit, or it might have run out of stack.
488    
489    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
490        happen only once. PCRE was, however incorrectly giving a compile time error
491        "recursive call could loop indefinitely" because it cannot analyze the
492        pattern in sufficient detail. The compile time test no longer happens when
493        PCRE is compiling a conditional subpattern, but actual runaway loops are
494        now caught at runtime (see 40 above).
495    
496    42. It seems that Perl allows any characters other than a closing parenthesis
497        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
498        has been changed to be the same.
499    
500    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
501        as not to get warnings when autogen.sh is called. Also changed
502        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
503    
504    44. To help people who use pcregrep to scan files containing exceedingly long
505        lines, the following changes have been made:
506    
507        (a) The default value of the buffer size parameter has been increased from
508            8K to 20K. (The actual buffer used is three times this size.)
509    
510        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
511            PCRE is built.
512    
513        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
514            to be set at run time.
515    
516        (d) Numerical values in pcregrep options can be followed by K or M, for
517            example --buffer-size=50K.
518    
519        (e) If a line being scanned overflows pcregrep's buffer, an error is now
520            given and the return code is set to 2.
521    
522    45. Add a pointer to the latest mark to the callout data block.
523    
524    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
525        partial match of an empty string instead of no match. This was specific to
526        the use of ".".
527    
528    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
529        complete match instead of a partial match. This bug was dependent on both
530        the PCRE_UTF8 and PCRE_DOTALL options being set.
531    
532    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
533        starting byte set, because \b was not being ignored.
534    
535    
536    Version 8.12 15-Jan-2011
537    ------------------------
538    
539    1.  Fixed some typos in the markup of the man pages, and wrote a script that
540        checks for such things as part of the documentation building process.
541    
542    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
543        --match-limit and --recursion-limit options (added for 8.11). In
544        particular, this made one of the standard tests fail. (The integer value
545        went into the wrong half of a long int.)
546    
547    3.  If the --colour option was given to pcregrep with -v (invert match), it
548        did strange things, either producing crazy output, or crashing. It should,
549        of course, ignore a request for colour when reporting lines that do not
550        match.
551    
552    4.  Another pcregrep bug caused similar problems if --colour was specified with
553        -M (multiline) and the pattern match finished with a line ending.
554    
555    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
556        matched in multiline mode, the following line was shown as part of the
557        match. This seems wrong, so I have changed it.
558    
559    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
560        the check for further matches in the same line (so they could be coloured)
561        to overrun the end of the current line. If another match was found, it was
562        incorrectly shown (and then shown again when found in the next line).
563    
564    7.  If pcregrep was compiled under Windows, there was a reference to the
565        function pcregrep_exit() before it was defined. I am assuming this was
566        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
567        reported by a user. I've moved the definition above the reference.
568    
569    
570    Version 8.11 10-Dec-2010
571    ------------------------
572    
573    1.  (*THEN) was not working properly if there were untried alternatives prior
574        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
575        backtracked to try for "b" instead of moving to the next alternative branch
576        at the same level (in this case, to look for "c"). The Perl documentation
577        is clear that when (*THEN) is backtracked onto, it goes to the "next
578        alternative in the innermost enclosing group".
579    
580    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
581        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
582        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
583        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
584        (*THEN).
585    
586    3.  If \s appeared in a character class, it removed the VT character from
587        the class, even if it had been included by some previous item, for example
588        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
589        of \s, but is part of the POSIX "space" class.)
590    
591    4.  A partial match never returns an empty string (because you can always
592        match an empty string at the end of the subject); however the checking for
593        an empty string was starting at the "start of match" point. This has been
594        changed to the "earliest inspected character" point, because the returned
595        data for a partial match starts at this character. This means that, for
596        example, /(?<=abc)def/ gives a partial match for the subject "abc"
597        (previously it gave "no match").
598    
599    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
600        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
601        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
602        has an implication that the given string is incomplete (because a partial
603        match is preferred over a full match). For this reason, these items now
604        give a partial match in this situation. [Aside: previously, the one case
605        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
606        match rather than a full match, which was wrong by the old rules, but is
607        now correct.]
608    
609    6.  There was a bug in the handling of #-introduced comments, recognized when
610        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
611        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
612        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
613        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
614        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
615        places in pcre_compile().
616    
617    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
618        comments when looking ahead for named forward references to subpatterns,
619        the only newline sequence it recognized was NL. It now handles newlines
620        according to the set newline convention.
621    
622    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
623        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
624        cater for a lack of strerror(). These oversights have been fixed.
625    
626    9.  Added --match-limit and --recursion-limit to pcregrep.
627    
628    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
629    
630    11. When the -o option was used, pcregrep was setting a return code of 1, even
631        when matches were found, and --line-buffered was not being honoured.
632    
633    12. Added an optional parentheses number to the -o and --only-matching options
634        of pcregrep.
635    
636    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
637        can match an empty string. The code to do it in pcretest and pcredemo
638        needed fixing:
639    
640        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
641            only one byte after an empty string match just before CRLF (this case
642            just got forgotten; "any" and "anycrlf" were OK).
643    
644        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
645            mode when an empty string match preceded an ASCII character followed by
646            a non-ASCII character. (The code for advancing by one character rather
647            than one byte was nonsense.)
648    
649        (c) The pcredemo.c sample program did not have any code at all to handle
650            the cases when CRLF is a valid newline sequence.
651    
652    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
653        as a starting offset was within the subject string. There is now a new
654        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
655        negative or greater than the length of the string. In order to test this,
656        pcretest is extended to allow the setting of negative starting offsets.
657    
658    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
659        starting offset points to the beginning of a UTF-8 character was
660        unnecessarily clumsy. I tidied it up.
661    
662    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
663        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
664    
665    17. Nobody had reported that the --include_dir option, which was added in
666        release 7.7 should have been called --include-dir (hyphen, not underscore)
667        for compatibility with GNU grep. I have changed it to --include-dir, but
668        left --include_dir as an undocumented synonym, and the same for
669        --exclude-dir, though that is not available in GNU grep, at least as of
670        release 2.5.4.
671    
672    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
673        characters from a string of bytes) have been redefined so as not to use
674        loops, in order to improve performance in some environments. At the same
675        time, I abstracted some of the common code into auxiliary macros to save
676        repetition (this should not affect the compiled code).
677    
678    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
679        compile-time error is now given if \c is not followed by an ASCII
680        character, that is, a byte less than 128. (In EBCDIC mode, the code is
681        different, and any byte value is allowed.)
682    
683    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
684        START_OPTIMIZE option, which is now allowed at compile time - but just
685        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
686        to pcregrep and other applications that have no direct access to PCRE
687        options. The new /Y option in pcretest sets this option when calling
688        pcre_compile().
689    
690    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
691        back references. Groups containing recursive back references were forced to
692        be atomic by that change, but in the case of named groups, the amount of
693        memory required was incorrectly computed, leading to "Failed: internal
694        error: code overflow". This has been fixed.
695    
696    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
697        pcretest.c, to avoid build problems in some Borland environments.
698    
699    
700    Version 8.10 25-Jun-2010
701    ------------------------
702    
703    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
704        THEN.
705    
706    2.  (*ACCEPT) was not working when inside an atomic group.
707    
708    3.  Inside a character class, \B is treated as a literal by default, but
709        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
710        causes the error). The code is unchanged, but I tidied the documentation.
711    
712    4.  Inside a character class, PCRE always treated \R and \X as literals,
713        whereas Perl faults them if its -w option is set. I have changed PCRE so
714        that it faults them when PCRE_EXTRA is set.
715    
716    5.  Added support for \N, which always matches any character other than
717        newline. (It is the same as "." when PCRE_DOTALL is not set.)
718    
719    6.  When compiling pcregrep with newer versions of gcc which may have
720        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
721        declared with attribute warn_unused_result" were given. Just casting the
722        result to (void) does not stop the warnings; a more elaborate fudge is
723        needed. I've used a macro to implement this.
724    
725    7.  Minor change to pcretest.c to avoid a compiler warning.
726    
727    8.  Added four artifical Unicode properties to help with an option to make
728        \s etc use properties (see next item). The new properties are: Xan
729        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
730    
731    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
732        use Unicode properties. (*UCP) at the start of a pattern can be used to set
733        this option. Modified pcretest to add /W to test this facility. Added
734        REG_UCP to make it available via the POSIX interface.
735    
736    10. Added --line-buffered to pcregrep.
737    
738    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
739        studied, and the match started with a letter with a code point greater than
740        127 whose first byte was different to the first byte of the other case of
741        the letter, the other case of this starting letter was not recognized
742        (#976).
743    
744    12. If a pattern that was studied started with a repeated Unicode property
745        test, for example, \p{Nd}+, there was the theoretical possibility of
746        setting up an incorrect bitmap of starting bytes, but fortunately it could
747        not have actually happened in practice until change 8 above was made (it
748        added property types that matched character-matching opcodes).
749    
750    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
751        possible starting bytes for non-anchored patterns.
752    
753    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
754        \R, and also a number of cases that involve Unicode properties, both
755        explicit and implicit when PCRE_UCP is set.
756    
757    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
758        input, it could crash or give wrong results if characters with values
759        greater than 0xc0 were present in the subject string. (Detail: it assumed
760        UTF-8 input when processing these items.)
761    
762    16. Added a lot of (int) casts to avoid compiler warnings in systems where
763        size_t is 64-bit (#991).
764    
765    17. Added a check for running out of memory when PCRE is compiled with
766        --disable-stack-for-recursion (#990).
767    
768    18. If the last data line in a file for pcretest does not have a newline on
769        the end, a newline was missing in the output.
770    
771    19. The default pcre_chartables.c file recognizes only ASCII characters (values
772        less than 128) in its various bitmaps. However, there is a facility for
773        generating tables according to the current locale when PCRE is compiled. It
774        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
775        characters, are recognized by isspace() and therefore were getting set in
776        these tables, and indeed these tables seem to approximate to ISO 8859. This
777        caused a problem in UTF-8 mode when pcre_study() was used to create a list
778        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
779        which of course cannot start UTF-8 characters. I have changed the code so
780        that only real ASCII characters (less than 128) and the correct starting
781        bytes for UTF-8 encodings are set for characters greater than 127 when in
782        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
783        altogether.)
784    
785    20. Added the /T option to pcretest so as to be able to run tests with non-
786        standard character tables, thus making it possible to include the tests
787        used for 19 above in the standard set of tests.
788    
789    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
790        reference to a subpattern the other side of a comment that contains an
791        opening parenthesis caused either an internal compiling error, or a
792        reference to the wrong subpattern.
793    
794    
795    Version 8.02 19-Mar-2010
796    ------------------------
797    
798    1.  The Unicode data tables have been updated to Unicode 5.2.0.
799    
800    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
801        configured.
802    
803    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
804        original author of that file, following a query about its status.
805    
806    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
807        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
808    
809    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
810        quantifier applied to a forward-referencing subroutine call, could compile
811        incorrect code or give the error "internal error: previously-checked
812        referenced subpattern not found".
813    
814    6.  Both MS Visual Studio and Symbian OS have problems with initializing
815        variables to point to external functions. For these systems, therefore,
816        pcre_malloc etc. are now initialized to local functions that call the
817        relevant global functions.
818    
819    7.  There were two entries missing in the vectors called coptable and poptable
820        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
821        I've fixed the data, and added a kludgy way of testing at compile time that
822        the lengths are correct (equal to the number of opcodes).
823    
824    8.  Following on from 7, I added a similar kludge to check the length of the
825        eint vector in pcreposix.c.
826    
827    9.  Error texts for pcre_compile() are held as one long string to avoid too
828        much relocation at load time. To find a text, the string is searched,
829        counting zeros. There was no check for running off the end of the string,
830        which could happen if a new error number was added without updating the
831        string.
832    
833    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
834    
835    11. \K was not working if it appeared in an atomic group or in a group that
836        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
837        \K is "not well defined" if used in an assertion. PCRE now accepts it if
838        the assertion is positive, but not if it is negative.
839    
840    12. Change 11 fortuitously reduced the size of the stack frame used in the
841        "match()" function of pcre_exec.c by one pointer. Forthcoming
842        implementation of support for (*MARK) will need an extra pointer on the
843        stack; I have reserved it now, so that the stack frame size does not
844        decrease.
845    
846    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
847        item in branch that calls a recursion is a subroutine call - as in the
848        second branch in the above example - was incorrectly given the compile-
849        time error "recursive call could loop indefinitely" because pcre_compile()
850        was not correctly checking the subroutine for matching a non-empty string.
851    
852    14. The checks for overrunning compiling workspace could trigger after an
853        overrun had occurred. This is a "should never occur" error, but it can be
854        triggered by pathological patterns such as hundreds of nested parentheses.
855        The checks now trigger 100 bytes before the end of the workspace.
856    
857    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
858    
859    
860    Version 8.01 19-Jan-2010
861    ------------------------
862    
863    1.  If a pattern contained a conditional subpattern with only one branch (in
864        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
865        computed the wrong minimum data length (which is of course zero for such
866        subpatterns). This could cause incorrect "no match" results.
867    
868    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
869        the pattern is reset in the first branch, pcre_compile() failed with
870        "internal error: code overflow at offset...". This happened only when
871        the reset was to the original external option setting. (An optimization
872        abstracts leading options settings into an external setting, which was the
873        cause of this.)
874    
875    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
876        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
877        assertion pattern did not match (meaning that the assertion was true), it
878        was incorrectly treated as false if the SKIP had been reached during the
879        matching. This also applied to assertions used as conditions.
880    
881    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
882        assertion subpattern, including such a pattern used as a condition,
883        unpredictable results occurred, instead of the error return
884        PCRE_ERROR_DFA_UITEM.
885    
886    5.  The C++ GlobalReplace function was not working like Perl for the special
887        situation when an empty string is matched. It now does the fancy magic
888        stuff that is necessary.
889    
890    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
891        removed. (These were left over from very, very early versions of PCRE.)
892    
893    7.  Some cosmetic changes to the code to make life easier when compiling it
894        as part of something else:
895    
896        (a) Change DEBUG to PCRE_DEBUG.
897    
898        (b) In pcre_compile(), rename the member of the "branch_chain" structure
899            called "current" as "current_branch", to prevent a collision with the
900            Linux macro when compiled as a kernel module.
901    
902        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
903            prevent a collision with the Linux macro when compiled as a kernel
904            module.
905    
906    8.  In pcre_compile() there are some checks for integer overflows that used to
907        cast potentially large values to (double). This has been changed to that
908        when building, a check for int64_t is made, and if it is found, it is used
909        instead, thus avoiding the use of floating point arithmetic. (There is no
910        other use of FP in PCRE.) If int64_t is not found, the fallback is to
911        double.
912    
913    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
914        2005 (difference between two addresses compared to an unsigned value).
915    
916    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
917        custom one, because of the following reported problem in Windows:
918    
919          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
920              under Win32.
921          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
922              therefore missing the function definition.
923          - The compiler thus generates a "C" signature for the test function.
924          - The linker fails to find the "C" function.
925          - PCRE fails to configure if asked to do so against libbz2.
926    
927    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
928        messages were output:
929    
930          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
931          rerunning libtoolize, to keep the correct libtool macros in-tree.
932          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
933    
934        I have done both of these things.
935    
936    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
937        most of the time, it *can* run out if it is given a pattern that contains a
938        runaway infinite recursion. I updated the discussion in the pcrestack man
939        page.
940    
941    13. Now that we have gone to the x.xx style of version numbers, the minor
942        version may start with zero. Using 08 or 09 is a bad idea because users
943        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
944        interpreted as invalid octal numbers. I've updated the previous comment in
945        configure.ac, and also added a check that gives an error if 08 or 09 are
946        used.
947    
948    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
949        causing partial matching to fail when the end of the subject matched \W
950        in a UTF-8 pattern where \W was quantified with a minimum of 3.
951    
952    15. There were some discrepancies between the declarations in pcre_internal.h
953        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
954        their definitions. The declarations used "const uschar *" and the
955        definitions used USPTR. Even though USPTR is normally defined as "const
956        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
957        reported that: "This difference in casting confuses some C++ compilers, for
958        example, SunCC recognizes above declarations as different functions and
959        generates broken code for hbpcre." I have changed the declarations to use
960        USPTR.
961    
962    16. GNU libtool is named differently on some systems. The autogen.sh script now
963        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
964        (FreeBSD).
965    
966    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
967        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
968        comment: "Figure out how to create a longlong from a string: strtoll and
969        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
970        instance, but it only takes 2 args instead of 3!"
971    
972    18. A subtle bug concerned with back references has been fixed by a change of
973        specification, with a corresponding code fix. A pattern such as
974        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
975        refers, was giving matches when it shouldn't. For example, xa=xaaa would
976        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
977        same bug. Such groups have to be quantified to be useful, or contained
978        inside another quantified group. (If there's no repetition, the reference
979        can never match.) The problem arises because, having left the group and
980        moved on to the rest of the pattern, a later failure that backtracks into
981        the group uses the captured value from the final iteration of the group
982        rather than the correct earlier one. I have fixed this in PCRE by forcing
983        any group that contains a reference to itself to be an atomic group; that
984        is, there cannot be any backtracking into it once it has completed. This is
985        similar to recursive and subroutine calls.
986    
987    
988    Version 8.00 19-Oct-09
989    ----------------------
990    
991    1.  The table for translating pcre_compile() error codes into POSIX error codes
992        was out-of-date, and there was no check on the pcre_compile() error code
993        being within the table. This could lead to an OK return being given in
994        error.
995    
996    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
997        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
998        in a Windows environment.
999    
1000    3.  The pcregrep --count option prints the count for each file even when it is
1001        zero, as does GNU grep. However, pcregrep was also printing all files when
1002        --files-with-matches was added. Now, when both options are given, it prints
1003        counts only for those files that have at least one match. (GNU grep just
1004        prints the file name in this circumstance, but including the count seems
1005        more useful - otherwise, why use --count?) Also ensured that the
1006        combination -clh just lists non-zero counts, with no names.
1007    
1008    4.  The long form of the pcregrep -F option was incorrectly implemented as
1009        --fixed_strings instead of --fixed-strings. This is an incompatible change,
1010        but it seems right to fix it, and I didn't think it was worth preserving
1011        the old behaviour.
1012    
1013    5.  The command line items --regex=pattern and --regexp=pattern were not
1014        recognized by pcregrep, which required --regex pattern or --regexp pattern
1015        (with a space rather than an '='). The man page documented the '=' forms,
1016        which are compatible with GNU grep; these now work.
1017    
1018    6.  No libpcreposix.pc file was created for pkg-config; there was just
1019        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1020    
1021    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1022        when UCP support is not needed, by modifying the Python script that
1023        generates it from Unicode data files. This should not matter if the module
1024        is correctly used as a library, but I received one complaint about 50K of
1025        unwanted data. My guess is that the person linked everything into his
1026        program rather than using a library. Anyway, it does no harm.
1027    
1028    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1029        was a minimum greater than 1 for a wide character in a possessive
1030        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1031        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1032        character. Chaos in the form of incorrect output or a compiling loop could
1033        result.
1034    
1035    9.  The restrictions on what a pattern can contain when partial matching is
1036        requested for pcre_exec() have been removed. All patterns can now be
1037        partially matched by this function. In addition, if there are at least two
1038        slots in the offset vector, the offset of the earliest inspected character
1039        for the match and the offset of the end of the subject are set in them when
1040        PCRE_ERROR_PARTIAL is returned.
1041    
1042    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1043        synonymous with PCRE_PARTIAL, for backwards compatibility, and
1044        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1045        and may be more useful for multi-segment matching.
1046    
1047    11. Partial matching with pcre_exec() is now more intuitive. A partial match
1048        used to be given if ever the end of the subject was reached; now it is
1049        given only if matching could not proceed because another character was
1050        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1051        string "Z", which now yields "no match" instead of "partial match". In the
1052        case of pcre_dfa_exec(), "no match" is given if every matching path for the
1053        final character ended with (*FAIL).
1054    
1055    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1056        if the pattern had a "must contain" character that was already found in the
1057        earlier partial match, unless partial matching was again requested. For
1058        example, with the pattern /dog.(body)?/, the "must contain" character is
1059        "g". If the first part-match was for the string "dog", restarting with
1060        "sbody" failed. This bug has been fixed.
1061    
1062    13. The string returned by pcre_dfa_exec() after a partial match has been
1063        changed so that it starts at the first inspected character rather than the
1064        first character of the match. This makes a difference only if the pattern
1065        starts with a lookbehind assertion or \b or \B (\K is not supported by
1066        pcre_dfa_exec()). It's an incompatible change, but it makes the two
1067        matching functions compatible, and I think it's the right thing to do.
1068    
1069    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1070        so that the demonstration program is easily available in environments where
1071        PCRE has not been installed from source.
1072    
1073    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1074        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1075        library.
1076    
1077    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1078        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1079        is not the first non-POSIX option to be added. Clearly some people find
1080        these options useful.
1081    
1082    17. If a caller to the POSIX matching function regexec() passes a non-zero
1083        value for nmatch with a NULL value for pmatch, the value of
1084        nmatch is forced to zero.
1085    
1086    18. RunGrepTest did not have a test for the availability of the -u option of
1087        the diff command, as RunTest does. It now checks in the same way as
1088        RunTest, and also checks for the -b option.
1089    
1090    19. If an odd number of negated classes containing just a single character
1091        interposed, within parentheses, between a forward reference to a named
1092        subpattern and the definition of the subpattern, compilation crashed with
1093        an internal error, complaining that it could not find the referenced
1094        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1095        [The bug was that it was starting one character too far in when skipping
1096        over the character class, thus treating the ] as data rather than
1097        terminating the class. This meant it could skip too much.]
1098    
1099    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1100        /g option in pcretest when the pattern contains \K, which makes it possible
1101        to have an empty string match not at the start, even when the pattern is
1102        anchored. Updated pcretest and pcredemo to use this option.
1103    
1104    21. If the maximum number of capturing subpatterns in a recursion was greater
1105        than the maximum at the outer level, the higher number was returned, but
1106        with unset values at the outer level. The correct (outer level) value is
1107        now given.
1108    
1109    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1110        PCRE did not set those parentheses (unlike Perl). I have now found a way to
1111        make it do so. The string so far is captured, making this feature
1112        compatible with Perl.
1113    
1114    23. The tests have been re-organized, adding tests 11 and 12, to make it
1115        possible to check the Perl 5.10 features against Perl 5.10.
1116    
1117    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1118        pattern matches a fixed length string. PCRE did not allow this; now it
1119        does. Neither allows recursion.
1120    
1121    25. I finally figured out how to implement a request to provide the minimum
1122        length of subject string that was needed in order to match a given pattern.
1123        (It was back references and recursion that I had previously got hung up
1124        on.) This code has now been added to pcre_study(); it finds a lower bound
1125        to the length of subject needed. It is not necessarily the greatest lower
1126        bound, but using it to avoid searching strings that are too short does give
1127        some useful speed-ups. The value is available to calling programs via
1128        pcre_fullinfo().
1129    
1130    26. While implementing 25, I discovered to my embarrassment that pcretest had
1131        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1132        study optimizations had never been tested with that matching function.
1133        Oops. What is worse, even when it was passed study data, there was a bug in
1134        pcre_dfa_exec() that meant it never actually used it. Double oops. There
1135        were also very few tests of studied patterns with pcre_dfa_exec().
1136    
1137    27. If (?| is used to create subpatterns with duplicate numbers, they are now
1138        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1139        on the other side of the coin, they are no longer allowed to have different
1140        names, because these cannot be distinguished in PCRE, and this has caused
1141        confusion. (This is a difference from Perl.)
1142    
1143    28. When duplicate subpattern names are present (necessarily with different
1144        numbers, as required by 27 above), and a test is made by name in a
1145        conditional pattern, either for a subpattern having been matched, or for
1146        recursion in such a pattern, all the associated numbered subpatterns are
1147        tested, and the overall condition is true if the condition is true for any
1148        one of them. This is the way Perl works, and is also more like the way
1149        testing by number works.
1150    
1151    
1152    Version 7.9 11-Apr-09
1153    ---------------------
1154    
1155    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1156        (pcretest), all targets were linked against these libraries. This included
1157        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1158        libraries. This caused unwanted dependencies to be created. This problem
1159        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1160        pcretest is linked with readline.
1161    
1162    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1163        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1164        moved outside it again, because FALSE and TRUE are already defined in AIX,
1165        but BOOL is not.
1166    
1167    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1168        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1169    
1170    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1171        hyphens) following file names and line numbers when outputting matching
1172        lines. This is not true; no spaces are inserted. I have also clarified the
1173        wording for the --colour (or --color) option.
1174    
1175    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1176        was not coloured; this is different to GNU grep, so I have changed it to be
1177        the same.
1178    
1179    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1180        each matching line was coloured. Now it goes on to look for further matches
1181        of any of the test patterns, which is the same behaviour as GNU grep.
1182    
1183    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1184        doesn't make sense to accept an empty string match in pcregrep, so I have
1185        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1186        seems to be how GNU grep behaves.
1187    
1188    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1189        start or after a newline", because the conditional assertion was not being
1190        correctly handled. The rule now is that both the assertion and what follows
1191        in the first alternative must satisfy the test.
1192    
1193    9.  If auto-callout was enabled in a pattern with a conditional group whose
1194        condition was an assertion, PCRE could crash during matching, both with
1195        pcre_exec() and pcre_dfa_exec().
1196    
1197    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1198        used for matching.
1199    
1200    11. Unicode property support in character classes was not working for
1201        characters (bytes) greater than 127 when not in UTF-8 mode.
1202    
1203    12. Added the -M command line option to pcretest.
1204    
1205    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1206    
1207    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1208    
1209    16. Added comments and documentation about mis-use of no_arg in the C++
1210        wrapper.
1211    
1212    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1213        from Martin Jerabek that uses macro names for all relevant character and
1214        string constants.
1215    
1216    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1217        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1218        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1219        these, but not everybody uses configure.
1220    
1221    19. A conditional group that had only one branch was not being correctly
1222        recognized as an item that could match an empty string. This meant that an
1223        enclosing group might also not be so recognized, causing infinite looping
1224        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1225        with the subject "ab", where knowledge that the repeated group can match
1226        nothing is needed in order to break the loop.
1227    
1228    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1229        exec(), but without supplying a callout function, matching went wrong.
1230    
1231    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1232        leak if the size of the offset vector was greater than 30. When the vector
1233        is smaller, the saved offsets during recursion go onto a local stack
1234        vector, but for larger vectors malloc() is used. It was failing to free
1235        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1236        error, in fact).
1237    
1238    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1239        heapframe that is used only when UTF-8 support is enabled. This caused no
1240        problem, but was untidy.
1241    
1242    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1243        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1244        included within another project.
1245    
1246    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1247        slightly modified by me:
1248    
1249          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1250              not building pcregrep.
1251    
1252          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1253              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1254    
1255    25. Forward references, both numeric and by name, in patterns that made use of
1256        duplicate group numbers, could behave incorrectly or give incorrect errors,
1257        because when scanning forward to find the reference group, PCRE was not
1258        taking into account the duplicate group numbers. A pattern such as
1259        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1260    
1261    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1262        the feature of a custom pointer more persuasive (as requested by a user).
1263    
1264    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1265        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1266        pre-defined.
1267    
1268    28. Added support for (*UTF8) at the start of a pattern.
1269    
1270    29. Arrange for flags added by the "release type" setting in CMake to be shown
1271        in the configuration summary.
1272    
1273    
1274    Version 7.8 05-Sep-08
1275  ---------------------  ---------------------
1276    
1277  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 13  Version 8.0 02 Jul-08 Line 1283  Version 8.0 02 Jul-08
1283    
1284  2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more  2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1285      scripts.      scripts.
1286    
1287  3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained  3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1288      a group with a zero qualifier. The result of the study could be incorrect,      a group with a zero qualifier. The result of the study could be incorrect,
1289      or the function might crash, depending on the pattern.      or the function might crash, depending on the pattern.
1290    
1291  4.  Caseless matching was not working for non-ASCII characters in back  4.  Caseless matching was not working for non-ASCII characters in back
1292      references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.      references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1293      It now works when Unicode Property Support is available.      It now works when Unicode Property Support is available.
1294    
1295  5.  In pcretest, an escape such as \x{de} in the data was always generating  5.  In pcretest, an escape such as \x{de} in the data was always generating
1296      a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in      a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1297      non-UTF-8 mode. If the value is greater than 255, it gives a warning about      non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1298      truncation.      truncation.
1299    
1300  6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).  6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1301    
1302    7.  Added two (int) casts to pcregrep when printing the difference of two
1303        pointers, in case they are 64-bit values.
1304    
1305    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1306        test 2 if it fails.
1307    
1308    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1309        and a #define of that name to empty if it is not externally set. This is to
1310        allow users of MSVC to set it if necessary.
1311    
1312    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1313        the convenience functions in the pcre_get.c source file.
1314    
1315    11. An option change at the start of a pattern that had top-level alternatives
1316        could cause overwriting and/or a crash. This command provoked a crash in
1317        some environments:
1318    
1319          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1320    
1321        This potential security problem was recorded as CVE-2008-2371.
1322    
1323    12. For a pattern where the match had to start at the beginning or immediately
1324        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1325        pcre_dfa_exec() could read past the end of the passed subject if there was
1326        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1327        pcretest so that it places the subject at the end of its malloc-ed buffer.
1328    
1329    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1330        exec() might read past the end of the data buffer in UTF-8 mode.
1331    
1332    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1333        the data contained the byte 0x85 as part of a UTF-8 character within its
1334        first line. This applied both to normal and DFA matching.
1335    
1336    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1337        /^[^d]*?$/8 failed to match "abc".
1338    
1339    16. Added a missing copyright notice to pcrecpp_internal.h.
1340    
1341    17. Make it more clear in the documentation that values returned from
1342        pcre_exec() in ovector are byte offsets, not character counts.
1343    
1344    18. Tidied a few places to stop certain compilers from issuing warnings.
1345    
1346    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1347        supplied by Stefan Weber. I made a further small update for 7.8 because
1348        there is a change of source arrangements: the pcre_searchfuncs.c module is
1349        replaced by pcre_ucd.c.
1350    
1351    
1352  Version 7.7 07-May-08  Version 7.7 07-May-08

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