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revision 302 by ph10, Sun Jan 20 19:12:46 2008 UTC revision 746 by ph10, Tue Nov 15 15:07:02 2011 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.6 19-Jan-08  Version 8.21
5    ------------
6    
7    1.  Updating the JIT compiler.
8    
9    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
10        are added as well.
11    
12    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
13        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
14        calling _pcre_jit_exec. Some extra comments are added.
15    
16    4.  Mark settings inside atomic groups that do not contain any capturing
17        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
18        was introduced by change 18 for 8.20.
19    
20    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
21        ECMA-262 standard.
22    
23    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
24        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
25        This bug was probably introduced by change 9 of 8.13.
26    
27    
28    Version 8.20 21-Oct-2011
29    ------------------------
30    
31    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
32        a POSIX class. After further experiments with Perl, which convinced me that
33        Perl has bugs and confusions, a closing square bracket is no longer allowed
34        in a POSIX name. This bug also affected patterns with classes that started
35        with full stops.
36    
37    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
38        captured substring, but while checking the failing first alternative,
39        substring 1 is temporarily captured. If the output vector supplied to
40        pcre_exec() was not big enough for this capture, the yield of the function
41        was still zero ("insufficient space for captured substrings"). This cannot
42        be totally fixed without adding another stack variable, which seems a lot
43        of expense for a edge case. However, I have improved the situation in cases
44        such as /(a)(b)x|abc/ matched against "abc", where the return code
45        indicates that fewer than the maximum number of slots in the ovector have
46        been set.
47    
48    3.  Related to (2) above: when there are more back references in a pattern than
49        slots in the output vector, pcre_exec() uses temporary memory during
50        matching, and copies in the captures as far as possible afterwards. It was
51        using the entire output vector, but this conflicts with the specification
52        that only 2/3 is used for passing back captured substrings. Now it uses
53        only the first 2/3, for compatibility. This is, of course, another edge
54        case.
55    
56    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
57        main code base, and can be used by building with --enable-jit. When this is
58        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
59        runtime --no-jit option is given.
60    
61    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
62        ovector, the return from the function was zero, implying that there were
63        other matches that did not fit. The correct "exactly full" value is now
64        returned.
65    
66    6.  If a subpattern that was called recursively or as a subroutine contained
67        (*PRUNE) or any other control that caused it to give a non-standard return,
68        invalid errors such as "Error -26 (nested recursion at the same subject
69        position)" or even infinite loops could occur.
70    
71    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
72        computing the minimum length on reaching *ACCEPT, and so ended up with the
73        wrong value of 1 rather than 0. Further investigation indicates that
74        computing a minimum subject length in the presence of *ACCEPT is difficult
75        (think back references, subroutine calls), and so I have changed the code
76        so that no minimum is registered for a pattern that contains *ACCEPT.
77    
78    8.  If (*THEN) was present in the first (true) branch of a conditional group,
79        it was not handled as intended. [But see 16 below.]
80    
81    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
82        Sheri Pierce.
83    
84    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
85        the first byte in a match must be "a".
86    
87    11. Change 17 for 8.13 increased the recursion depth for patterns like
88        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
89        pattern contains any instances of (*THEN). If it does not, the old
90        optimizations are restored. It would be nice to do this on a per-group
91        basis, but at the moment that is not feasible.
92    
93    12. In some environments, the output of pcretest -C is CRLF terminated. This
94        broke RunTest's code that checks for the link size. A single white space
95        character after the value is now allowed for.
96    
97    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
98        For "fr", it uses the Windows-specific input and output files.
99    
100    14. If (*THEN) appeared in a group that was called recursively or as a
101        subroutine, it did not work as intended. [But see next item.]
102    
103    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
104        pattern fragments (but not containing any | characters). If A and B are
105        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
106        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
107        D. In other words, Perl considers parentheses that do not contain any |
108        characters to be part of a surrounding alternative, whereas PCRE was
109        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
110        differently. PCRE now behaves in the same way as Perl, except in the case
111        of subroutine/recursion calls such as (?1) which have in any case always
112        been different (but PCRE had them first :-).
113    
114    16. Related to 15 above: Perl does not treat the | in a conditional group as
115        creating alternatives. Such a group is treated in the same way as an
116        ordinary group without any | characters when processing (*THEN). PCRE has
117        been changed to match Perl's behaviour.
118    
119    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
120        RunGrepTest script failed.
121    
122    18. Change 22 for version 13 caused atomic groups to use more stack. This is
123        inevitable for groups that contain captures, but it can lead to a lot of
124        stack use in large patterns. The old behaviour has been restored for atomic
125        groups that do not contain any capturing parentheses.
126    
127    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
128        suppress the check for a minimum subject length at run time. (If it was
129        given to pcre_exec() or pcre_dfa_exec() it did work.)
130    
131    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
132        fail to work when decoding hex characters in data strings in EBCDIC
133        environments.
134    
135    21. It appears that in at least one Mac OS environment, the isxdigit() function
136        is implemented as a macro that evaluates to its argument more than once,
137        contravening the C 90 Standard (I haven't checked a later standard). There
138        was an instance in pcretest which caused it to go wrong when processing
139        \x{...} escapes in subject strings. The has been rewritten to avoid using
140        things like p++ in the argument of isxdigit().
141    
142    
143    Version 8.13 16-Aug-2011
144    ------------------------
145    
146    1.  The Unicode data tables have been updated to Unicode 6.0.0.
147    
148    2.  Two minor typos in pcre_internal.h have been fixed.
149    
150    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
151        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
152        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
153    
154    4.  There were a number of related bugs in the code for matching backrefences
155        caselessly in UTF-8 mode when codes for the characters concerned were
156        different numbers of bytes. For example, U+023A and U+2C65 are an upper
157        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
158        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
159        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
160        2-byte code at the end of the subject (it thought there wasn't enough data
161        left).
162    
163    5.  Comprehensive information about what went wrong is now returned by
164        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
165        as the output vector has at least 2 elements. The offset of the start of
166        the failing character and a reason code are placed in the vector.
167    
168    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
169        now returned is for the first byte of the failing character, instead of the
170        last byte inspected. This is an incompatible change, but I hope it is small
171        enough not to be a problem. It makes the returned offset consistent with
172        pcre_exec() and pcre_dfa_exec().
173    
174    7.  pcretest now gives a text phrase as well as the error number when
175        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
176        failure, the offset and reason code are output.
177    
178    8.  When \R was used with a maximizing quantifier it failed to skip backwards
179        over a \r\n pair if the subsequent match failed. Instead, it just skipped
180        back over a single character (\n). This seems wrong (because it treated the
181        two characters as a single entity when going forwards), conflicts with the
182        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
183        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
184        has been changed.
185    
186    9.  Some internal refactoring has changed the processing so that the handling
187        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
188        time (the PCRE_DOTALL option was changed this way some time ago: version
189        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
190        which was always a bit of a fudge. It also means that there is one less
191        argument for the match() function, which reduces its stack requirements
192        slightly. This change also fixes an incompatibility with Perl: the pattern
193        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
194    
195    10. More internal refactoring has drastically reduced the number of recursive
196        calls to match() for possessively repeated groups such as (abc)++ when
197        using pcre_exec().
198    
199    11. While implementing 10, a number of bugs in the handling of groups were
200        discovered and fixed:
201    
202        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
203        (a|)*(?1) gave a compile-time internal error.
204        ((a|)+)+  did not notice that the outer group could match an empty string.
205        (^a|^)+   was not marked as anchored.
206        (.*a|.*)+ was not marked as matching at start or after a newline.
207    
208    12. Yet more internal refactoring has removed another argument from the match()
209        function. Special calls to this function are now indicated by setting a
210        value in a variable in the "match data" data block.
211    
212    13. Be more explicit in pcre_study() instead of relying on "default" for
213        opcodes that mean there is no starting character; this means that when new
214        ones are added and accidentally left out of pcre_study(), testing should
215        pick them up.
216    
217    14. The -s option of pcretest has been documented for ages as being an old
218        synonym of -m (show memory usage). I have changed it to mean "force study
219        for every regex", that is, assume /S for every regex. This is similar to -i
220        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
221        using it. It makes it easier to run collections of tests with and without
222        study enabled, and thereby test pcre_study() more easily. All the standard
223        tests are now run with and without -s (but some patterns can be marked as
224        "never study" - see 20 below).
225    
226    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
227        restoration of the capturing data to the outer values was not happening
228        correctly.
229    
230    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
231        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
232        pattern had matched an empty string, and so incorrectly returned a no
233        match.
234    
235    17. There was optimizing code for the last branch of non-capturing parentheses,
236        and also for the obeyed branch of a conditional subexpression, which used
237        tail recursion to cut down on stack usage. Unfortunately, now that there is
238        the possibility of (*THEN) occurring in these branches, tail recursion is
239        no longer possible because the return has to be checked for (*THEN). These
240        two optimizations have therefore been removed. [But see 8.20/11 above.]
241    
242    18. If a pattern containing \R was studied, it was assumed that \R always
243        matched two bytes, thus causing the minimum subject length to be
244        incorrectly computed because \R can also match just one byte.
245    
246    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
247        was incorrectly computed.
248    
249    20. If /S is present twice on a test pattern in pcretest input, it now
250        *disables* studying, thereby overriding the use of -s on the command line
251        (see 14 above). This is necessary for one or two tests to keep the output
252        identical in both cases.
253    
254    21. When (*ACCEPT) was used in an assertion that matched an empty string and
255        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
256    
257    22. When an atomic group that contained a capturing parenthesis was
258        successfully matched, but the branch in which it appeared failed, the
259        capturing was not being forgotten if a higher numbered group was later
260        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
261        group 1 to "a", when in fact it should be unset. This applied to multi-
262        branched capturing and non-capturing groups, repeated or not, and also to
263        positive assertions (capturing in negative assertions does not happen
264        in PCRE) and also to nested atomic groups.
265    
266    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
267        subject after a captured substring, to make it easier to tell which of a
268        number of identical substrings has been captured.
269    
270    24. The way atomic groups are processed by pcre_exec() has been changed so that
271        if they are repeated, backtracking one repetition now resets captured
272        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
273        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
274        "aaa". Previously, it would have been "a". As part of this code
275        refactoring, the way recursive calls are handled has also been changed.
276    
277    25. If an assertion condition captured any substrings, they were not passed
278        back unless some other capturing happened later. For example, if
279        (?(?=(a))a) was matched against "a", no capturing was returned.
280    
281    26. When studying a pattern that contained subroutine calls or assertions,
282        the code for finding the minimum length of a possible match was handling
283        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
284        group 1 called group 2 while simultaneously a separate group 2 called group
285        1). A stack overflow occurred in this case. I have fixed this by limiting
286        the recursion depth to 10.
287    
288    27. Updated RunTest.bat in the distribution to the version supplied by Tom
289        Fortmann. This supports explicit test numbers on the command line, and has
290        argument validation and error reporting.
291    
292    28. An instance of \X with an unlimited repeat could fail if at any point the
293        first character it looked at was a mark character.
294    
295    29. Some minor code refactoring concerning Unicode properties and scripts
296        should reduce the stack requirement of match() slightly.
297    
298    30. Added the '=' option to pcretest to check the setting of unused capturing
299        slots at the end of the pattern, which are documented as being -1, but are
300        not included in the return count.
301    
302    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
303        compiled something random. Now it gives a compile-time error (as does
304        Perl).
305    
306    32. A *MARK encountered during the processing of a positive assertion is now
307        recorded and passed back (compatible with Perl).
308    
309    33. If --only-matching or --colour was set on a pcregrep call whose pattern
310        had alternative anchored branches, the search for a second match in a line
311        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
312        matched the line "0102" twice. The same bug affected patterns that started
313        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
314        twice.
315    
316    34. Previously, PCRE did not allow quantification of assertions. However, Perl
317        does, and because of capturing effects, quantifying parenthesized
318        assertions may at times be useful. Quantifiers are now allowed for
319        parenthesized assertions.
320    
321    35. A minor code tidy in pcre_compile() when checking options for \R usage.
322    
323    36. \g was being checked for fancy things in a character class, when it should
324        just be a literal "g".
325    
326    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
327        appearance of a nested POSIX class supersedes an apparent external class.
328        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
329        unescaped square brackets may also appear as part of class names. For
330        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
331        more like Perl. (But see 8.20/1 above.)
332    
333    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
334        was because it thought it was \N{name}, which is not supported).
335    
336    39. Add minix to OS list not supporting the -S option in pcretest.
337    
338    40. PCRE tries to detect cases of infinite recursion at compile time, but it
339        cannot analyze patterns in sufficient detail to catch mutual recursions
340        such as ((?1))((?2)). There is now a runtime test that gives an error if a
341        subgroup is called recursively as a subpattern for a second time at the
342        same position in the subject string. In previous releases this might have
343        been caught by the recursion limit, or it might have run out of stack.
344    
345    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
346        happen only once. PCRE was, however incorrectly giving a compile time error
347        "recursive call could loop indefinitely" because it cannot analyze the
348        pattern in sufficient detail. The compile time test no longer happens when
349        PCRE is compiling a conditional subpattern, but actual runaway loops are
350        now caught at runtime (see 40 above).
351    
352    42. It seems that Perl allows any characters other than a closing parenthesis
353        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
354        has been changed to be the same.
355    
356    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
357        as not to get warnings when autogen.sh is called. Also changed
358        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
359    
360    44. To help people who use pcregrep to scan files containing exceedingly long
361        lines, the following changes have been made:
362    
363        (a) The default value of the buffer size parameter has been increased from
364            8K to 20K. (The actual buffer used is three times this size.)
365    
366        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
367            PCRE is built.
368    
369        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
370            to be set at run time.
371    
372        (d) Numerical values in pcregrep options can be followed by K or M, for
373            example --buffer-size=50K.
374    
375        (e) If a line being scanned overflows pcregrep's buffer, an error is now
376            given and the return code is set to 2.
377    
378    45. Add a pointer to the latest mark to the callout data block.
379    
380    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
381        partial match of an empty string instead of no match. This was specific to
382        the use of ".".
383    
384    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
385        complete match instead of a partial match. This bug was dependent on both
386        the PCRE_UTF8 and PCRE_DOTALL options being set.
387    
388    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
389        starting byte set, because \b was not being ignored.
390    
391    
392    Version 8.12 15-Jan-2011
393    ------------------------
394    
395    1.  Fixed some typos in the markup of the man pages, and wrote a script that
396        checks for such things as part of the documentation building process.
397    
398    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
399        --match-limit and --recursion-limit options (added for 8.11). In
400        particular, this made one of the standard tests fail. (The integer value
401        went into the wrong half of a long int.)
402    
403    3.  If the --colour option was given to pcregrep with -v (invert match), it
404        did strange things, either producing crazy output, or crashing. It should,
405        of course, ignore a request for colour when reporting lines that do not
406        match.
407    
408    4.  Another pcregrep bug caused similar problems if --colour was specified with
409        -M (multiline) and the pattern match finished with a line ending.
410    
411    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
412        matched in multiline mode, the following line was shown as part of the
413        match. This seems wrong, so I have changed it.
414    
415    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
416        the check for further matches in the same line (so they could be coloured)
417        to overrun the end of the current line. If another match was found, it was
418        incorrectly shown (and then shown again when found in the next line).
419    
420    7.  If pcregrep was compiled under Windows, there was a reference to the
421        function pcregrep_exit() before it was defined. I am assuming this was
422        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
423        reported by a user. I've moved the definition above the reference.
424    
425    
426    Version 8.11 10-Dec-2010
427    ------------------------
428    
429    1.  (*THEN) was not working properly if there were untried alternatives prior
430        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
431        backtracked to try for "b" instead of moving to the next alternative branch
432        at the same level (in this case, to look for "c"). The Perl documentation
433        is clear that when (*THEN) is backtracked onto, it goes to the "next
434        alternative in the innermost enclosing group".
435    
436    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
437        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
438        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
439        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
440        (*THEN).
441    
442    3.  If \s appeared in a character class, it removed the VT character from
443        the class, even if it had been included by some previous item, for example
444        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
445        of \s, but is part of the POSIX "space" class.)
446    
447    4.  A partial match never returns an empty string (because you can always
448        match an empty string at the end of the subject); however the checking for
449        an empty string was starting at the "start of match" point. This has been
450        changed to the "earliest inspected character" point, because the returned
451        data for a partial match starts at this character. This means that, for
452        example, /(?<=abc)def/ gives a partial match for the subject "abc"
453        (previously it gave "no match").
454    
455    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
456        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
457        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
458        has an implication that the given string is incomplete (because a partial
459        match is preferred over a full match). For this reason, these items now
460        give a partial match in this situation. [Aside: previously, the one case
461        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
462        match rather than a full match, which was wrong by the old rules, but is
463        now correct.]
464    
465    6.  There was a bug in the handling of #-introduced comments, recognized when
466        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
467        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
468        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
469        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
470        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
471        places in pcre_compile().
472    
473    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
474        comments when looking ahead for named forward references to subpatterns,
475        the only newline sequence it recognized was NL. It now handles newlines
476        according to the set newline convention.
477    
478    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
479        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
480        cater for a lack of strerror(). These oversights have been fixed.
481    
482    9.  Added --match-limit and --recursion-limit to pcregrep.
483    
484    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
485    
486    11. When the -o option was used, pcregrep was setting a return code of 1, even
487        when matches were found, and --line-buffered was not being honoured.
488    
489    12. Added an optional parentheses number to the -o and --only-matching options
490        of pcregrep.
491    
492    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
493        can match an empty string. The code to do it in pcretest and pcredemo
494        needed fixing:
495    
496        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
497            only one byte after an empty string match just before CRLF (this case
498            just got forgotten; "any" and "anycrlf" were OK).
499    
500        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
501            mode when an empty string match preceded an ASCII character followed by
502            a non-ASCII character. (The code for advancing by one character rather
503            than one byte was nonsense.)
504    
505        (c) The pcredemo.c sample program did not have any code at all to handle
506            the cases when CRLF is a valid newline sequence.
507    
508    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
509        as a starting offset was within the subject string. There is now a new
510        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
511        negative or greater than the length of the string. In order to test this,
512        pcretest is extended to allow the setting of negative starting offsets.
513    
514    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
515        starting offset points to the beginning of a UTF-8 character was
516        unnecessarily clumsy. I tidied it up.
517    
518    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
519        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
520    
521    17. Nobody had reported that the --include_dir option, which was added in
522        release 7.7 should have been called --include-dir (hyphen, not underscore)
523        for compatibility with GNU grep. I have changed it to --include-dir, but
524        left --include_dir as an undocumented synonym, and the same for
525        --exclude-dir, though that is not available in GNU grep, at least as of
526        release 2.5.4.
527    
528    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
529        characters from a string of bytes) have been redefined so as not to use
530        loops, in order to improve performance in some environments. At the same
531        time, I abstracted some of the common code into auxiliary macros to save
532        repetition (this should not affect the compiled code).
533    
534    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
535        compile-time error is now given if \c is not followed by an ASCII
536        character, that is, a byte less than 128. (In EBCDIC mode, the code is
537        different, and any byte value is allowed.)
538    
539    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
540        START_OPTIMIZE option, which is now allowed at compile time - but just
541        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
542        to pcregrep and other applications that have no direct access to PCRE
543        options. The new /Y option in pcretest sets this option when calling
544        pcre_compile().
545    
546    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
547        back references. Groups containing recursive back references were forced to
548        be atomic by that change, but in the case of named groups, the amount of
549        memory required was incorrectly computed, leading to "Failed: internal
550        error: code overflow". This has been fixed.
551    
552    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
553        pcretest.c, to avoid build problems in some Borland environments.
554    
555    
556    Version 8.10 25-Jun-2010
557    ------------------------
558    
559    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
560        THEN.
561    
562    2.  (*ACCEPT) was not working when inside an atomic group.
563    
564    3.  Inside a character class, \B is treated as a literal by default, but
565        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
566        causes the error). The code is unchanged, but I tidied the documentation.
567    
568    4.  Inside a character class, PCRE always treated \R and \X as literals,
569        whereas Perl faults them if its -w option is set. I have changed PCRE so
570        that it faults them when PCRE_EXTRA is set.
571    
572    5.  Added support for \N, which always matches any character other than
573        newline. (It is the same as "." when PCRE_DOTALL is not set.)
574    
575    6.  When compiling pcregrep with newer versions of gcc which may have
576        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
577        declared with attribute warn_unused_result" were given. Just casting the
578        result to (void) does not stop the warnings; a more elaborate fudge is
579        needed. I've used a macro to implement this.
580    
581    7.  Minor change to pcretest.c to avoid a compiler warning.
582    
583    8.  Added four artifical Unicode properties to help with an option to make
584        \s etc use properties (see next item). The new properties are: Xan
585        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
586    
587    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
588        use Unicode properties. (*UCP) at the start of a pattern can be used to set
589        this option. Modified pcretest to add /W to test this facility. Added
590        REG_UCP to make it available via the POSIX interface.
591    
592    10. Added --line-buffered to pcregrep.
593    
594    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
595        studied, and the match started with a letter with a code point greater than
596        127 whose first byte was different to the first byte of the other case of
597        the letter, the other case of this starting letter was not recognized
598        (#976).
599    
600    12. If a pattern that was studied started with a repeated Unicode property
601        test, for example, \p{Nd}+, there was the theoretical possibility of
602        setting up an incorrect bitmap of starting bytes, but fortunately it could
603        not have actually happened in practice until change 8 above was made (it
604        added property types that matched character-matching opcodes).
605    
606    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
607        possible starting bytes for non-anchored patterns.
608    
609    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
610        \R, and also a number of cases that involve Unicode properties, both
611        explicit and implicit when PCRE_UCP is set.
612    
613    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
614        input, it could crash or give wrong results if characters with values
615        greater than 0xc0 were present in the subject string. (Detail: it assumed
616        UTF-8 input when processing these items.)
617    
618    16. Added a lot of (int) casts to avoid compiler warnings in systems where
619        size_t is 64-bit (#991).
620    
621    17. Added a check for running out of memory when PCRE is compiled with
622        --disable-stack-for-recursion (#990).
623    
624    18. If the last data line in a file for pcretest does not have a newline on
625        the end, a newline was missing in the output.
626    
627    19. The default pcre_chartables.c file recognizes only ASCII characters (values
628        less than 128) in its various bitmaps. However, there is a facility for
629        generating tables according to the current locale when PCRE is compiled. It
630        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
631        characters, are recognized by isspace() and therefore were getting set in
632        these tables, and indeed these tables seem to approximate to ISO 8859. This
633        caused a problem in UTF-8 mode when pcre_study() was used to create a list
634        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
635        which of course cannot start UTF-8 characters. I have changed the code so
636        that only real ASCII characters (less than 128) and the correct starting
637        bytes for UTF-8 encodings are set for characters greater than 127 when in
638        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
639        altogether.)
640    
641    20. Added the /T option to pcretest so as to be able to run tests with non-
642        standard character tables, thus making it possible to include the tests
643        used for 19 above in the standard set of tests.
644    
645    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
646        reference to a subpattern the other side of a comment that contains an
647        opening parenthesis caused either an internal compiling error, or a
648        reference to the wrong subpattern.
649    
650    
651    Version 8.02 19-Mar-2010
652    ------------------------
653    
654    1.  The Unicode data tables have been updated to Unicode 5.2.0.
655    
656    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
657        configured.
658    
659    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
660        original author of that file, following a query about its status.
661    
662    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
663        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
664    
665    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
666        quantifier applied to a forward-referencing subroutine call, could compile
667        incorrect code or give the error "internal error: previously-checked
668        referenced subpattern not found".
669    
670    6.  Both MS Visual Studio and Symbian OS have problems with initializing
671        variables to point to external functions. For these systems, therefore,
672        pcre_malloc etc. are now initialized to local functions that call the
673        relevant global functions.
674    
675    7.  There were two entries missing in the vectors called coptable and poptable
676        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
677        I've fixed the data, and added a kludgy way of testing at compile time that
678        the lengths are correct (equal to the number of opcodes).
679    
680    8.  Following on from 7, I added a similar kludge to check the length of the
681        eint vector in pcreposix.c.
682    
683    9.  Error texts for pcre_compile() are held as one long string to avoid too
684        much relocation at load time. To find a text, the string is searched,
685        counting zeros. There was no check for running off the end of the string,
686        which could happen if a new error number was added without updating the
687        string.
688    
689    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
690    
691    11. \K was not working if it appeared in an atomic group or in a group that
692        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
693        \K is "not well defined" if used in an assertion. PCRE now accepts it if
694        the assertion is positive, but not if it is negative.
695    
696    12. Change 11 fortuitously reduced the size of the stack frame used in the
697        "match()" function of pcre_exec.c by one pointer. Forthcoming
698        implementation of support for (*MARK) will need an extra pointer on the
699        stack; I have reserved it now, so that the stack frame size does not
700        decrease.
701    
702    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
703        item in branch that calls a recursion is a subroutine call - as in the
704        second branch in the above example - was incorrectly given the compile-
705        time error "recursive call could loop indefinitely" because pcre_compile()
706        was not correctly checking the subroutine for matching a non-empty string.
707    
708    14. The checks for overrunning compiling workspace could trigger after an
709        overrun had occurred. This is a "should never occur" error, but it can be
710        triggered by pathological patterns such as hundreds of nested parentheses.
711        The checks now trigger 100 bytes before the end of the workspace.
712    
713    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
714    
715    
716    Version 8.01 19-Jan-2010
717    ------------------------
718    
719    1.  If a pattern contained a conditional subpattern with only one branch (in
720        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
721        computed the wrong minimum data length (which is of course zero for such
722        subpatterns). This could cause incorrect "no match" results.
723    
724    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
725        the pattern is reset in the first branch, pcre_compile() failed with
726        "internal error: code overflow at offset...". This happened only when
727        the reset was to the original external option setting. (An optimization
728        abstracts leading options settings into an external setting, which was the
729        cause of this.)
730    
731    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
732        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
733        assertion pattern did not match (meaning that the assertion was true), it
734        was incorrectly treated as false if the SKIP had been reached during the
735        matching. This also applied to assertions used as conditions.
736    
737    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
738        assertion subpattern, including such a pattern used as a condition,
739        unpredictable results occurred, instead of the error return
740        PCRE_ERROR_DFA_UITEM.
741    
742    5.  The C++ GlobalReplace function was not working like Perl for the special
743        situation when an empty string is matched. It now does the fancy magic
744        stuff that is necessary.
745    
746    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
747        removed. (These were left over from very, very early versions of PCRE.)
748    
749    7.  Some cosmetic changes to the code to make life easier when compiling it
750        as part of something else:
751    
752        (a) Change DEBUG to PCRE_DEBUG.
753    
754        (b) In pcre_compile(), rename the member of the "branch_chain" structure
755            called "current" as "current_branch", to prevent a collision with the
756            Linux macro when compiled as a kernel module.
757    
758        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
759            prevent a collision with the Linux macro when compiled as a kernel
760            module.
761    
762    8.  In pcre_compile() there are some checks for integer overflows that used to
763        cast potentially large values to (double). This has been changed to that
764        when building, a check for int64_t is made, and if it is found, it is used
765        instead, thus avoiding the use of floating point arithmetic. (There is no
766        other use of FP in PCRE.) If int64_t is not found, the fallback is to
767        double.
768    
769    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
770        2005 (difference between two addresses compared to an unsigned value).
771    
772    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
773        custom one, because of the following reported problem in Windows:
774    
775          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
776              under Win32.
777          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
778              therefore missing the function definition.
779          - The compiler thus generates a "C" signature for the test function.
780          - The linker fails to find the "C" function.
781          - PCRE fails to configure if asked to do so against libbz2.
782    
783    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
784        messages were output:
785    
786          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
787          rerunning libtoolize, to keep the correct libtool macros in-tree.
788          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
789    
790        I have done both of these things.
791    
792    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
793        most of the time, it *can* run out if it is given a pattern that contains a
794        runaway infinite recursion. I updated the discussion in the pcrestack man
795        page.
796    
797    13. Now that we have gone to the x.xx style of version numbers, the minor
798        version may start with zero. Using 08 or 09 is a bad idea because users
799        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
800        interpreted as invalid octal numbers. I've updated the previous comment in
801        configure.ac, and also added a check that gives an error if 08 or 09 are
802        used.
803    
804    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
805        causing partial matching to fail when the end of the subject matched \W
806        in a UTF-8 pattern where \W was quantified with a minimum of 3.
807    
808    15. There were some discrepancies between the declarations in pcre_internal.h
809        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
810        their definitions. The declarations used "const uschar *" and the
811        definitions used USPTR. Even though USPTR is normally defined as "const
812        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
813        reported that: "This difference in casting confuses some C++ compilers, for
814        example, SunCC recognizes above declarations as different functions and
815        generates broken code for hbpcre." I have changed the declarations to use
816        USPTR.
817    
818    16. GNU libtool is named differently on some systems. The autogen.sh script now
819        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
820        (FreeBSD).
821    
822    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
823        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
824        comment: "Figure out how to create a longlong from a string: strtoll and
825        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
826        instance, but it only takes 2 args instead of 3!"
827    
828    18. A subtle bug concerned with back references has been fixed by a change of
829        specification, with a corresponding code fix. A pattern such as
830        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
831        refers, was giving matches when it shouldn't. For example, xa=xaaa would
832        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
833        same bug. Such groups have to be quantified to be useful, or contained
834        inside another quantified group. (If there's no repetition, the reference
835        can never match.) The problem arises because, having left the group and
836        moved on to the rest of the pattern, a later failure that backtracks into
837        the group uses the captured value from the final iteration of the group
838        rather than the correct earlier one. I have fixed this in PCRE by forcing
839        any group that contains a reference to itself to be an atomic group; that
840        is, there cannot be any backtracking into it once it has completed. This is
841        similar to recursive and subroutine calls.
842    
843    
844    Version 8.00 19-Oct-09
845    ----------------------
846    
847    1.  The table for translating pcre_compile() error codes into POSIX error codes
848        was out-of-date, and there was no check on the pcre_compile() error code
849        being within the table. This could lead to an OK return being given in
850        error.
851    
852    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
853        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
854        in a Windows environment.
855    
856    3.  The pcregrep --count option prints the count for each file even when it is
857        zero, as does GNU grep. However, pcregrep was also printing all files when
858        --files-with-matches was added. Now, when both options are given, it prints
859        counts only for those files that have at least one match. (GNU grep just
860        prints the file name in this circumstance, but including the count seems
861        more useful - otherwise, why use --count?) Also ensured that the
862        combination -clh just lists non-zero counts, with no names.
863    
864    4.  The long form of the pcregrep -F option was incorrectly implemented as
865        --fixed_strings instead of --fixed-strings. This is an incompatible change,
866        but it seems right to fix it, and I didn't think it was worth preserving
867        the old behaviour.
868    
869    5.  The command line items --regex=pattern and --regexp=pattern were not
870        recognized by pcregrep, which required --regex pattern or --regexp pattern
871        (with a space rather than an '='). The man page documented the '=' forms,
872        which are compatible with GNU grep; these now work.
873    
874    6.  No libpcreposix.pc file was created for pkg-config; there was just
875        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
876    
877    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
878        when UCP support is not needed, by modifying the Python script that
879        generates it from Unicode data files. This should not matter if the module
880        is correctly used as a library, but I received one complaint about 50K of
881        unwanted data. My guess is that the person linked everything into his
882        program rather than using a library. Anyway, it does no harm.
883    
884    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
885        was a minimum greater than 1 for a wide character in a possessive
886        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
887        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
888        character. Chaos in the form of incorrect output or a compiling loop could
889        result.
890    
891    9.  The restrictions on what a pattern can contain when partial matching is
892        requested for pcre_exec() have been removed. All patterns can now be
893        partially matched by this function. In addition, if there are at least two
894        slots in the offset vector, the offset of the earliest inspected character
895        for the match and the offset of the end of the subject are set in them when
896        PCRE_ERROR_PARTIAL is returned.
897    
898    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
899        synonymous with PCRE_PARTIAL, for backwards compatibility, and
900        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
901        and may be more useful for multi-segment matching.
902    
903    11. Partial matching with pcre_exec() is now more intuitive. A partial match
904        used to be given if ever the end of the subject was reached; now it is
905        given only if matching could not proceed because another character was
906        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
907        string "Z", which now yields "no match" instead of "partial match". In the
908        case of pcre_dfa_exec(), "no match" is given if every matching path for the
909        final character ended with (*FAIL).
910    
911    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
912        if the pattern had a "must contain" character that was already found in the
913        earlier partial match, unless partial matching was again requested. For
914        example, with the pattern /dog.(body)?/, the "must contain" character is
915        "g". If the first part-match was for the string "dog", restarting with
916        "sbody" failed. This bug has been fixed.
917    
918    13. The string returned by pcre_dfa_exec() after a partial match has been
919        changed so that it starts at the first inspected character rather than the
920        first character of the match. This makes a difference only if the pattern
921        starts with a lookbehind assertion or \b or \B (\K is not supported by
922        pcre_dfa_exec()). It's an incompatible change, but it makes the two
923        matching functions compatible, and I think it's the right thing to do.
924    
925    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
926        so that the demonstration program is easily available in environments where
927        PCRE has not been installed from source.
928    
929    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
930        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
931        library.
932    
933    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
934        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
935        is not the first non-POSIX option to be added. Clearly some people find
936        these options useful.
937    
938    17. If a caller to the POSIX matching function regexec() passes a non-zero
939        value for nmatch with a NULL value for pmatch, the value of
940        nmatch is forced to zero.
941    
942    18. RunGrepTest did not have a test for the availability of the -u option of
943        the diff command, as RunTest does. It now checks in the same way as
944        RunTest, and also checks for the -b option.
945    
946    19. If an odd number of negated classes containing just a single character
947        interposed, within parentheses, between a forward reference to a named
948        subpattern and the definition of the subpattern, compilation crashed with
949        an internal error, complaining that it could not find the referenced
950        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
951        [The bug was that it was starting one character too far in when skipping
952        over the character class, thus treating the ] as data rather than
953        terminating the class. This meant it could skip too much.]
954    
955    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
956        /g option in pcretest when the pattern contains \K, which makes it possible
957        to have an empty string match not at the start, even when the pattern is
958        anchored. Updated pcretest and pcredemo to use this option.
959    
960    21. If the maximum number of capturing subpatterns in a recursion was greater
961        than the maximum at the outer level, the higher number was returned, but
962        with unset values at the outer level. The correct (outer level) value is
963        now given.
964    
965    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
966        PCRE did not set those parentheses (unlike Perl). I have now found a way to
967        make it do so. The string so far is captured, making this feature
968        compatible with Perl.
969    
970    23. The tests have been re-organized, adding tests 11 and 12, to make it
971        possible to check the Perl 5.10 features against Perl 5.10.
972    
973    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
974        pattern matches a fixed length string. PCRE did not allow this; now it
975        does. Neither allows recursion.
976    
977    25. I finally figured out how to implement a request to provide the minimum
978        length of subject string that was needed in order to match a given pattern.
979        (It was back references and recursion that I had previously got hung up
980        on.) This code has now been added to pcre_study(); it finds a lower bound
981        to the length of subject needed. It is not necessarily the greatest lower
982        bound, but using it to avoid searching strings that are too short does give
983        some useful speed-ups. The value is available to calling programs via
984        pcre_fullinfo().
985    
986    26. While implementing 25, I discovered to my embarrassment that pcretest had
987        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
988        study optimizations had never been tested with that matching function.
989        Oops. What is worse, even when it was passed study data, there was a bug in
990        pcre_dfa_exec() that meant it never actually used it. Double oops. There
991        were also very few tests of studied patterns with pcre_dfa_exec().
992    
993    27. If (?| is used to create subpatterns with duplicate numbers, they are now
994        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
995        on the other side of the coin, they are no longer allowed to have different
996        names, because these cannot be distinguished in PCRE, and this has caused
997        confusion. (This is a difference from Perl.)
998    
999    28. When duplicate subpattern names are present (necessarily with different
1000        numbers, as required by 27 above), and a test is made by name in a
1001        conditional pattern, either for a subpattern having been matched, or for
1002        recursion in such a pattern, all the associated numbered subpatterns are
1003        tested, and the overall condition is true if the condition is true for any
1004        one of them. This is the way Perl works, and is also more like the way
1005        testing by number works.
1006    
1007    
1008    Version 7.9 11-Apr-09
1009    ---------------------
1010    
1011    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
1012        (pcretest), all targets were linked against these libraries. This included
1013        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1014        libraries. This caused unwanted dependencies to be created. This problem
1015        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1016        pcretest is linked with readline.
1017    
1018    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
1019        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1020        moved outside it again, because FALSE and TRUE are already defined in AIX,
1021        but BOOL is not.
1022    
1023    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1024        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1025    
1026    4.  The pcregrep documentation said spaces were inserted as well as colons (or
1027        hyphens) following file names and line numbers when outputting matching
1028        lines. This is not true; no spaces are inserted. I have also clarified the
1029        wording for the --colour (or --color) option.
1030    
1031    5.  In pcregrep, when --colour was used with -o, the list of matching strings
1032        was not coloured; this is different to GNU grep, so I have changed it to be
1033        the same.
1034    
1035    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
1036        each matching line was coloured. Now it goes on to look for further matches
1037        of any of the test patterns, which is the same behaviour as GNU grep.
1038    
1039    7.  A pattern that could match an empty string could cause pcregrep to loop; it
1040        doesn't make sense to accept an empty string match in pcregrep, so I have
1041        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1042        seems to be how GNU grep behaves.
1043    
1044    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1045        start or after a newline", because the conditional assertion was not being
1046        correctly handled. The rule now is that both the assertion and what follows
1047        in the first alternative must satisfy the test.
1048    
1049    9.  If auto-callout was enabled in a pattern with a conditional group whose
1050        condition was an assertion, PCRE could crash during matching, both with
1051        pcre_exec() and pcre_dfa_exec().
1052    
1053    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1054        used for matching.
1055    
1056    11. Unicode property support in character classes was not working for
1057        characters (bytes) greater than 127 when not in UTF-8 mode.
1058    
1059    12. Added the -M command line option to pcretest.
1060    
1061    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1062    
1063    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1064    
1065    16. Added comments and documentation about mis-use of no_arg in the C++
1066        wrapper.
1067    
1068    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1069        from Martin Jerabek that uses macro names for all relevant character and
1070        string constants.
1071    
1072    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1073        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1074        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1075        these, but not everybody uses configure.
1076    
1077    19. A conditional group that had only one branch was not being correctly
1078        recognized as an item that could match an empty string. This meant that an
1079        enclosing group might also not be so recognized, causing infinite looping
1080        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1081        with the subject "ab", where knowledge that the repeated group can match
1082        nothing is needed in order to break the loop.
1083    
1084    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1085        exec(), but without supplying a callout function, matching went wrong.
1086    
1087    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1088        leak if the size of the offset vector was greater than 30. When the vector
1089        is smaller, the saved offsets during recursion go onto a local stack
1090        vector, but for larger vectors malloc() is used. It was failing to free
1091        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1092        error, in fact).
1093    
1094    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1095        heapframe that is used only when UTF-8 support is enabled. This caused no
1096        problem, but was untidy.
1097    
1098    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1099        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1100        included within another project.
1101    
1102    24. Steven Van Ingelgem's patches to add more options to the CMake support,
1103        slightly modified by me:
1104    
1105          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1106              not building pcregrep.
1107    
1108          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1109              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1110    
1111    25. Forward references, both numeric and by name, in patterns that made use of
1112        duplicate group numbers, could behave incorrectly or give incorrect errors,
1113        because when scanning forward to find the reference group, PCRE was not
1114        taking into account the duplicate group numbers. A pattern such as
1115        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1116    
1117    26. Changed a few more instances of "const unsigned char *" to USPTR, making
1118        the feature of a custom pointer more persuasive (as requested by a user).
1119    
1120    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1121        pcretest.c, inside #ifndefs, because it seems they are sometimes already
1122        pre-defined.
1123    
1124    28. Added support for (*UTF8) at the start of a pattern.
1125    
1126    29. Arrange for flags added by the "release type" setting in CMake to be shown
1127        in the configuration summary.
1128    
1129    
1130    Version 7.8 05-Sep-08
1131    ---------------------
1132    
1133    1.  Replaced UCP searching code with optimized version as implemented for Ad
1134        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1135        stage table and inline lookup instead of a function, giving speed ups of 2
1136        to 5 times on some simple patterns that I tested. Permission was given to
1137        distribute the MultiStage2.py script that generates the tables (it's not in
1138        the tarball, but is in the Subversion repository).
1139    
1140    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1141        scripts.
1142    
1143    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1144        a group with a zero qualifier. The result of the study could be incorrect,
1145        or the function might crash, depending on the pattern.
1146    
1147    4.  Caseless matching was not working for non-ASCII characters in back
1148        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1149        It now works when Unicode Property Support is available.
1150    
1151    5.  In pcretest, an escape such as \x{de} in the data was always generating
1152        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1153        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1154        truncation.
1155    
1156    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1157    
1158    7.  Added two (int) casts to pcregrep when printing the difference of two
1159        pointers, in case they are 64-bit values.
1160    
1161    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
1162        test 2 if it fails.
1163    
1164    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1165        and a #define of that name to empty if it is not externally set. This is to
1166        allow users of MSVC to set it if necessary.
1167    
1168    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1169        the convenience functions in the pcre_get.c source file.
1170    
1171    11. An option change at the start of a pattern that had top-level alternatives
1172        could cause overwriting and/or a crash. This command provoked a crash in
1173        some environments:
1174    
1175          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1176    
1177        This potential security problem was recorded as CVE-2008-2371.
1178    
1179    12. For a pattern where the match had to start at the beginning or immediately
1180        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1181        pcre_dfa_exec() could read past the end of the passed subject if there was
1182        no match. To help with detecting such bugs (e.g. with valgrind), I modified
1183        pcretest so that it places the subject at the end of its malloc-ed buffer.
1184    
1185    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1186        exec() might read past the end of the data buffer in UTF-8 mode.
1187    
1188    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1189        the data contained the byte 0x85 as part of a UTF-8 character within its
1190        first line. This applied both to normal and DFA matching.
1191    
1192    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1193        /^[^d]*?$/8 failed to match "abc".
1194    
1195    16. Added a missing copyright notice to pcrecpp_internal.h.
1196    
1197    17. Make it more clear in the documentation that values returned from
1198        pcre_exec() in ovector are byte offsets, not character counts.
1199    
1200    18. Tidied a few places to stop certain compilers from issuing warnings.
1201    
1202    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1203        supplied by Stefan Weber. I made a further small update for 7.8 because
1204        there is a change of source arrangements: the pcre_searchfuncs.c module is
1205        replaced by pcre_ucd.c.
1206    
1207    
1208    Version 7.7 07-May-08
1209    ---------------------
1210    
1211    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
1212        a string to a long long, pretend we don't even have a long long." This is
1213        done by checking for the strtoq, strtoll, and _strtoi64 functions.
1214    
1215    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1216        pre-7.6 versions, which defined a global no_arg variable instead of putting
1217        it in the RE class. (See also #8 below.)
1218    
1219    3.  Remove a line of dead code, identified by coverity and reported by Nuno
1220        Lopes.
1221    
1222    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
1223    
1224        (1) The include/exclude patterns were being applied to the whole pathnames
1225            of files, instead of just to the final components.
1226    
1227        (2) If there was more than one level of directory, the subdirectories were
1228            skipped unless they satisfied the include/exclude conditions. This is
1229            inconsistent with GNU grep (and could even be seen as contrary to the
1230            pcregrep specification - which I improved to make it absolutely clear).
1231            The action now is always to scan all levels of directory, and just
1232            apply the include/exclude patterns to regular files.
1233    
1234    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1235        --exclude_dir in the tests to avoid scanning .svn directories.
1236    
1237    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
1238        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1239        doesn't support NULs in patterns.
1240    
1241    7.  Added some missing "const"s to declarations of static tables in
1242        pcre_compile.c and pcre_dfa_exec.c.
1243    
1244    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1245        caused by fix #2  above. (Subsequently also a second patch to fix the
1246        first patch. And a third patch - this was a messy problem.)
1247    
1248    9.  Applied Craig's patch to remove the use of push_back().
1249    
1250    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1251        matching function regexec().
1252    
1253    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1254        which, however, unlike Perl's \g{...}, are subroutine calls, not back
1255        references. PCRE supports relative numbers with this syntax (I don't think
1256        Oniguruma does).
1257    
1258    12. Previously, a group with a zero repeat such as (...){0} was completely
1259        omitted from the compiled regex. However, this means that if the group
1260        was called as a subroutine from elsewhere in the pattern, things went wrong
1261        (an internal error was given). Such groups are now left in the compiled
1262        pattern, with a new opcode that causes them to be skipped at execution
1263        time.
1264    
1265    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1266        to the way PCRE behaves:
1267    
1268        (a) A lone ] character is dis-allowed (Perl treats it as data).
1269    
1270        (b) A back reference to an unmatched subpattern matches an empty string
1271            (Perl fails the current match path).
1272    
1273        (c) A data ] in a character class must be notated as \] because if the
1274            first data character in a class is ], it defines an empty class. (In
1275            Perl it is not possible to have an empty class.) The empty class []
1276            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1277            The negative empty class [^] matches any one character, independently
1278            of the DOTALL setting.
1279    
1280    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1281        non-existent subpattern following a character class starting with ']' and
1282        containing () gave an internal compiling error instead of "reference to
1283        non-existent subpattern". Fortunately, when the pattern did exist, the
1284        compiled code was correct. (When scanning forwards to check for the
1285        existencd of the subpattern, it was treating the data ']' as terminating
1286        the class, so got the count wrong. When actually compiling, the reference
1287        was subsequently set up correctly.)
1288    
1289    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1290        it was being rejected as not supported by pcre_dfa_exec(), even though
1291        other assertions are supported. I have made pcre_dfa_exec() support
1292        (*FAIL).
1293    
1294    16. The implementation of 13c above involved the invention of a new opcode,
1295        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1296        cannot be changed at match time, I realized I could make a small
1297        improvement to matching performance by compiling OP_ALLANY instead of
1298        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1299        on the OP_ANY path.
1300    
1301    17. Compiling pcretest on Windows with readline support failed without the
1302        following two fixes: (1) Make the unistd.h include conditional on
1303        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1304    
1305    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1306        ncurses library to be included for pcretest when ReadLine support is
1307        requested, but also to allow for it to be overridden. This patch came from
1308        Daniel Bergström.
1309    
1310    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1311        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1312        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1313        spotting this.
1314    
1315    
1316    Version 7.6 28-Jan-08
1317  ---------------------  ---------------------
1318    
1319  1.  A character class containing a very large number of characters with  1.  A character class containing a very large number of characters with
1320      codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer      codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1321      overflow.      overflow.
1322    
1323  2.  Patch to cut out the "long long" test in pcrecpp_unittest when  2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1324      HAVE_LONG_LONG is not defined.      HAVE_LONG_LONG is not defined.
1325    
1326    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1327        bring them up to date and include new features. This patch includes:
1328    
1329        - Fixed PH's badly added libz and libbz2 support.
1330        - Fixed a problem with static linking.
1331        - Added pcredemo. [But later removed - see 7 below.]
1332        - Fixed dftables problem and added an option.
1333        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1334            HAVE_LONG_LONG.
1335        - Added readline support for pcretest.
1336        - Added an listing of the option settings after cmake has run.
1337    
1338    4.  A user submitted a patch to Makefile that makes it easy to create
1339        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1340        Makefile.am that cause it to include this special target, without
1341        affecting anything else. Note that the same mingw target plus all
1342        the other distribution libraries and programs are now supported
1343        when configuring with CMake (see 6 below) instead of with
1344        Configure/Make.
1345    
1346    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1347        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1348        exported in the Windows port". It has not yet been confirmed that the patch
1349        solves the problem, but it does no harm.
1350    
1351    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1352        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1353        with CMake, and also correct the comment about stack recursion.
1354    
1355    7.  Remove the automatic building of pcredemo from the ./configure system and
1356        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1357        of a program that users should build themselves after PCRE is installed, so
1358        building it automatically is not really right. What is more, it gave
1359        trouble in some build environments.
1360    
1361    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1362    
1363    
1364  Version 7.5 10-Jan-08  Version 7.5 10-Jan-08
1365  ---------------------  ---------------------

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