/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 195 by ph10, Mon Jul 30 13:23:28 2007 UTC revision 609 by ph10, Wed Jun 15 18:09:23 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.3 05-Jul-07  Version 8.13 30-Apr-2011
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
8    
9    2.  Two minor typos in pcre_internal.h have been fixed.
10    
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
14    
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
23    
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
28    
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
34    
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
38    
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
46    
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55    
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
59    
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
62    
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
68    
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
72    
73    13. Be more explicit in pcre_study() instead of relying on "default" for
74        opcodes that mean there is no starting character; this means that when new
75        ones are added and accidentally left out of pcre_study(), testing should
76        pick them up.
77    
78    14. The -s option of pcretest has been documented for ages as being an old
79        synonym of -m (show memory usage). I have changed it to mean "force study
80        for every regex", that is, assume /S for every regex. This is similar to -i
81        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82        using it. It makes it easier to run collection of tests with study enabled,
83        and thereby test pcre_study() more easily.
84    
85    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
86        restoration of the capturing data to the outer values was not happening
87        correctly.
88    
89    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
90        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
91        pattern had matched an empty string, and so incorrectly returned a no
92        match.
93    
94    17. There was optimizing code for the last branch of non-capturing parentheses,
95        and also for the obeyed branch of a conditional subexpression, which used
96        tail recursion to cut down on stack usage. Unfortunately, not that there is
97        the possibility of (*THEN) occurring in these branches, tail recursion is
98        no longer possible because the return has to be checked for (*THEN). These
99        two optimizations have therefore been removed.
100    
101    
102    Version 8.12 15-Jan-2011
103    ------------------------
104    
105    1.  Fixed some typos in the markup of the man pages, and wrote a script that
106        checks for such things as part of the documentation building process.
107    
108    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
109        --match-limit and --recursion-limit options (added for 8.11). In
110        particular, this made one of the standard tests fail. (The integer value
111        went into the wrong half of a long int.)
112    
113    3.  If the --colour option was given to pcregrep with -v (invert match), it
114        did strange things, either producing crazy output, or crashing. It should,
115        of course, ignore a request for colour when reporting lines that do not
116        match.
117    
118    4.  Another pcregrep bug caused similar problems if --colour was specified with
119        -M (multiline) and the pattern match finished with a line ending.
120    
121    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
122        matched in multiline mode, the following line was shown as part of the
123        match. This seems wrong, so I have changed it.
124    
125    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
126        the check for further matches in the same line (so they could be coloured)
127        to overrun the end of the current line. If another match was found, it was
128        incorrectly shown (and then shown again when found in the next line).
129    
130    7.  If pcregrep was compiled under Windows, there was a reference to the
131        function pcregrep_exit() before it was defined. I am assuming this was
132        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
133        reported by a user. I've moved the definition above the reference.
134    
135    
136    Version 8.11 10-Dec-2010
137    ------------------------
138    
139    1.  (*THEN) was not working properly if there were untried alternatives prior
140        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
141        backtracked to try for "b" instead of moving to the next alternative branch
142        at the same level (in this case, to look for "c"). The Perl documentation
143        is clear that when (*THEN) is backtracked onto, it goes to the "next
144        alternative in the innermost enclosing group".
145    
146    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
147        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
148        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
149        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
150        (*THEN).
151    
152    3.  If \s appeared in a character class, it removed the VT character from
153        the class, even if it had been included by some previous item, for example
154        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
155        of \s, but is part of the POSIX "space" class.)
156    
157    4.  A partial match never returns an empty string (because you can always
158        match an empty string at the end of the subject); however the checking for
159        an empty string was starting at the "start of match" point. This has been
160        changed to the "earliest inspected character" point, because the returned
161        data for a partial match starts at this character. This means that, for
162        example, /(?<=abc)def/ gives a partial match for the subject "abc"
163        (previously it gave "no match").
164    
165    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
166        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
167        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
168        has an implication that the given string is incomplete (because a partial
169        match is preferred over a full match). For this reason, these items now
170        give a partial match in this situation. [Aside: previously, the one case
171        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
172        match rather than a full match, which was wrong by the old rules, but is
173        now correct.]
174    
175    6.  There was a bug in the handling of #-introduced comments, recognized when
176        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
177        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
178        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
179        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
180        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
181        places in pcre_compile().
182    
183    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
184        comments when looking ahead for named forward references to subpatterns,
185        the only newline sequence it recognized was NL. It now handles newlines
186        according to the set newline convention.
187    
188    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
189        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
190        cater for a lack of strerror(). These oversights have been fixed.
191    
192    9.  Added --match-limit and --recursion-limit to pcregrep.
193    
194    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
195    
196    11. When the -o option was used, pcregrep was setting a return code of 1, even
197        when matches were found, and --line-buffered was not being honoured.
198    
199    12. Added an optional parentheses number to the -o and --only-matching options
200        of pcregrep.
201    
202    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
203        can match an empty string. The code to do it in pcretest and pcredemo
204        needed fixing:
205    
206        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
207            only one byte after an empty string match just before CRLF (this case
208            just got forgotten; "any" and "anycrlf" were OK).
209    
210        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
211            mode when an empty string match preceded an ASCII character followed by
212            a non-ASCII character. (The code for advancing by one character rather
213            than one byte was nonsense.)
214    
215        (c) The pcredemo.c sample program did not have any code at all to handle
216            the cases when CRLF is a valid newline sequence.
217    
218    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
219        as a starting offset was within the subject string. There is now a new
220        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
221        negative or greater than the length of the string. In order to test this,
222        pcretest is extended to allow the setting of negative starting offsets.
223    
224    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
225        starting offset points to the beginning of a UTF-8 character was
226        unnecessarily clumsy. I tidied it up.
227    
228    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
229        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
230    
231    17. Nobody had reported that the --include_dir option, which was added in
232        release 7.7 should have been called --include-dir (hyphen, not underscore)
233        for compatibility with GNU grep. I have changed it to --include-dir, but
234        left --include_dir as an undocumented synonym, and the same for
235        --exclude-dir, though that is not available in GNU grep, at least as of
236        release 2.5.4.
237    
238    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
239        characters from a string of bytes) have been redefined so as not to use
240        loops, in order to improve performance in some environments. At the same
241        time, I abstracted some of the common code into auxiliary macros to save
242        repetition (this should not affect the compiled code).
243    
244    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
245        compile-time error is now given if \c is not followed by an ASCII
246        character, that is, a byte less than 128. (In EBCDIC mode, the code is
247        different, and any byte value is allowed.)
248    
249    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
250        START_OPTIMIZE option, which is now allowed at compile time - but just
251        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
252        to pcregrep and other applications that have no direct access to PCRE
253        options. The new /Y option in pcretest sets this option when calling
254        pcre_compile().
255    
256    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
257        back references. Groups containing recursive back references were forced to
258        be atomic by that change, but in the case of named groups, the amount of
259        memory required was incorrectly computed, leading to "Failed: internal
260        error: code overflow". This has been fixed.
261    
262    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
263        pcretest.c, to avoid build problems in some Borland environments.
264    
265    
266    Version 8.10 25-Jun-2010
267    ------------------------
268    
269    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
270        THEN.
271    
272    2.  (*ACCEPT) was not working when inside an atomic group.
273    
274    3.  Inside a character class, \B is treated as a literal by default, but
275        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
276        causes the error). The code is unchanged, but I tidied the documentation.
277    
278    4.  Inside a character class, PCRE always treated \R and \X as literals,
279        whereas Perl faults them if its -w option is set. I have changed PCRE so
280        that it faults them when PCRE_EXTRA is set.
281    
282    5.  Added support for \N, which always matches any character other than
283        newline. (It is the same as "." when PCRE_DOTALL is not set.)
284    
285    6.  When compiling pcregrep with newer versions of gcc which may have
286        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
287        declared with attribute warn_unused_result" were given. Just casting the
288        result to (void) does not stop the warnings; a more elaborate fudge is
289        needed. I've used a macro to implement this.
290    
291    7.  Minor change to pcretest.c to avoid a compiler warning.
292    
293    8.  Added four artifical Unicode properties to help with an option to make
294        \s etc use properties (see next item). The new properties are: Xan
295        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
296    
297    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
298        use Unicode properties. (*UCP) at the start of a pattern can be used to set
299        this option. Modified pcretest to add /W to test this facility. Added
300        REG_UCP to make it available via the POSIX interface.
301    
302    10. Added --line-buffered to pcregrep.
303    
304    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
305        studied, and the match started with a letter with a code point greater than
306        127 whose first byte was different to the first byte of the other case of
307        the letter, the other case of this starting letter was not recognized
308        (#976).
309    
310    12. If a pattern that was studied started with a repeated Unicode property
311        test, for example, \p{Nd}+, there was the theoretical possibility of
312        setting up an incorrect bitmap of starting bytes, but fortunately it could
313        not have actually happened in practice until change 8 above was made (it
314        added property types that matched character-matching opcodes).
315    
316    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
317        possible starting bytes for non-anchored patterns.
318    
319    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
320        \R, and also a number of cases that involve Unicode properties, both
321        explicit and implicit when PCRE_UCP is set.
322    
323    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
324        input, it could crash or give wrong results if characters with values
325        greater than 0xc0 were present in the subject string. (Detail: it assumed
326        UTF-8 input when processing these items.)
327    
328    16. Added a lot of (int) casts to avoid compiler warnings in systems where
329        size_t is 64-bit (#991).
330    
331    17. Added a check for running out of memory when PCRE is compiled with
332        --disable-stack-for-recursion (#990).
333    
334    18. If the last data line in a file for pcretest does not have a newline on
335        the end, a newline was missing in the output.
336    
337    19. The default pcre_chartables.c file recognizes only ASCII characters (values
338        less than 128) in its various bitmaps. However, there is a facility for
339        generating tables according to the current locale when PCRE is compiled. It
340        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
341        characters, are recognized by isspace() and therefore were getting set in
342        these tables, and indeed these tables seem to approximate to ISO 8859. This
343        caused a problem in UTF-8 mode when pcre_study() was used to create a list
344        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
345        which of course cannot start UTF-8 characters. I have changed the code so
346        that only real ASCII characters (less than 128) and the correct starting
347        bytes for UTF-8 encodings are set for characters greater than 127 when in
348        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
349        altogether.)
350    
351    20. Added the /T option to pcretest so as to be able to run tests with non-
352        standard character tables, thus making it possible to include the tests
353        used for 19 above in the standard set of tests.
354    
355    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
356        reference to a subpattern the other side of a comment that contains an
357        opening parenthesis caused either an internal compiling error, or a
358        reference to the wrong subpattern.
359    
360    
361    Version 8.02 19-Mar-2010
362    ------------------------
363    
364    1.  The Unicode data tables have been updated to Unicode 5.2.0.
365    
366    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
367        configured.
368    
369    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
370        original author of that file, following a query about its status.
371    
372    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
373        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
374    
375    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
376        quantifier applied to a forward-referencing subroutine call, could compile
377        incorrect code or give the error "internal error: previously-checked
378        referenced subpattern not found".
379    
380    6.  Both MS Visual Studio and Symbian OS have problems with initializing
381        variables to point to external functions. For these systems, therefore,
382        pcre_malloc etc. are now initialized to local functions that call the
383        relevant global functions.
384    
385    7.  There were two entries missing in the vectors called coptable and poptable
386        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
387        I've fixed the data, and added a kludgy way of testing at compile time that
388        the lengths are correct (equal to the number of opcodes).
389    
390    8.  Following on from 7, I added a similar kludge to check the length of the
391        eint vector in pcreposix.c.
392    
393    9.  Error texts for pcre_compile() are held as one long string to avoid too
394        much relocation at load time. To find a text, the string is searched,
395        counting zeros. There was no check for running off the end of the string,
396        which could happen if a new error number was added without updating the
397        string.
398    
399    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
400    
401    11. \K was not working if it appeared in an atomic group or in a group that
402        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
403        \K is "not well defined" if used in an assertion. PCRE now accepts it if
404        the assertion is positive, but not if it is negative.
405    
406    12. Change 11 fortuitously reduced the size of the stack frame used in the
407        "match()" function of pcre_exec.c by one pointer. Forthcoming
408        implementation of support for (*MARK) will need an extra pointer on the
409        stack; I have reserved it now, so that the stack frame size does not
410        decrease.
411    
412    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
413        item in branch that calls a recursion is a subroutine call - as in the
414        second branch in the above example - was incorrectly given the compile-
415        time error "recursive call could loop indefinitely" because pcre_compile()
416        was not correctly checking the subroutine for matching a non-empty string.
417    
418    14. The checks for overrunning compiling workspace could trigger after an
419        overrun had occurred. This is a "should never occur" error, but it can be
420        triggered by pathological patterns such as hundreds of nested parentheses.
421        The checks now trigger 100 bytes before the end of the workspace.
422    
423    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
424    
425    
426    Version 8.01 19-Jan-2010
427    ------------------------
428    
429    1.  If a pattern contained a conditional subpattern with only one branch (in
430        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
431        computed the wrong minimum data length (which is of course zero for such
432        subpatterns). This could cause incorrect "no match" results.
433    
434    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
435        the pattern is reset in the first branch, pcre_compile() failed with
436        "internal error: code overflow at offset...". This happened only when
437        the reset was to the original external option setting. (An optimization
438        abstracts leading options settings into an external setting, which was the
439        cause of this.)
440    
441    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
442        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
443        assertion pattern did not match (meaning that the assertion was true), it
444        was incorrectly treated as false if the SKIP had been reached during the
445        matching. This also applied to assertions used as conditions.
446    
447    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
448        assertion subpattern, including such a pattern used as a condition,
449        unpredictable results occurred, instead of the error return
450        PCRE_ERROR_DFA_UITEM.
451    
452    5.  The C++ GlobalReplace function was not working like Perl for the special
453        situation when an empty string is matched. It now does the fancy magic
454        stuff that is necessary.
455    
456    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
457        removed. (These were left over from very, very early versions of PCRE.)
458    
459    7.  Some cosmetic changes to the code to make life easier when compiling it
460        as part of something else:
461    
462        (a) Change DEBUG to PCRE_DEBUG.
463    
464        (b) In pcre_compile(), rename the member of the "branch_chain" structure
465            called "current" as "current_branch", to prevent a collision with the
466            Linux macro when compiled as a kernel module.
467    
468        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
469            prevent a collision with the Linux macro when compiled as a kernel
470            module.
471    
472    8.  In pcre_compile() there are some checks for integer overflows that used to
473        cast potentially large values to (double). This has been changed to that
474        when building, a check for int64_t is made, and if it is found, it is used
475        instead, thus avoiding the use of floating point arithmetic. (There is no
476        other use of FP in PCRE.) If int64_t is not found, the fallback is to
477        double.
478    
479    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
480        2005 (difference between two addresses compared to an unsigned value).
481    
482    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
483        custom one, because of the following reported problem in Windows:
484    
485          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
486              under Win32.
487          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
488              therefore missing the function definition.
489          - The compiler thus generates a "C" signature for the test function.
490          - The linker fails to find the "C" function.
491          - PCRE fails to configure if asked to do so against libbz2.
492    
493    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
494        messages were output:
495    
496          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
497          rerunning libtoolize, to keep the correct libtool macros in-tree.
498          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
499    
500        I have done both of these things.
501    
502    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
503        most of the time, it *can* run out if it is given a pattern that contains a
504        runaway infinite recursion. I updated the discussion in the pcrestack man
505        page.
506    
507    13. Now that we have gone to the x.xx style of version numbers, the minor
508        version may start with zero. Using 08 or 09 is a bad idea because users
509        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
510        interpreted as invalid octal numbers. I've updated the previous comment in
511        configure.ac, and also added a check that gives an error if 08 or 09 are
512        used.
513    
514    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
515        causing partial matching to fail when the end of the subject matched \W
516        in a UTF-8 pattern where \W was quantified with a minimum of 3.
517    
518    15. There were some discrepancies between the declarations in pcre_internal.h
519        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
520        their definitions. The declarations used "const uschar *" and the
521        definitions used USPTR. Even though USPTR is normally defined as "const
522        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
523        reported that: "This difference in casting confuses some C++ compilers, for
524        example, SunCC recognizes above declarations as different functions and
525        generates broken code for hbpcre." I have changed the declarations to use
526        USPTR.
527    
528    16. GNU libtool is named differently on some systems. The autogen.sh script now
529        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
530        (FreeBSD).
531    
532    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
533        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
534        comment: "Figure out how to create a longlong from a string: strtoll and
535        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
536        instance, but it only takes 2 args instead of 3!"
537    
538    18. A subtle bug concerned with back references has been fixed by a change of
539        specification, with a corresponding code fix. A pattern such as
540        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
541        refers, was giving matches when it shouldn't. For example, xa=xaaa would
542        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
543        same bug. Such groups have to be quantified to be useful, or contained
544        inside another quantified group. (If there's no repetition, the reference
545        can never match.) The problem arises because, having left the group and
546        moved on to the rest of the pattern, a later failure that backtracks into
547        the group uses the captured value from the final iteration of the group
548        rather than the correct earlier one. I have fixed this in PCRE by forcing
549        any group that contains a reference to itself to be an atomic group; that
550        is, there cannot be any backtracking into it once it has completed. This is
551        similar to recursive and subroutine calls.
552    
553    
554    Version 8.00 19-Oct-09
555    ----------------------
556    
557    1.  The table for translating pcre_compile() error codes into POSIX error codes
558        was out-of-date, and there was no check on the pcre_compile() error code
559        being within the table. This could lead to an OK return being given in
560        error.
561    
562    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
563        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
564        in a Windows environment.
565    
566    3.  The pcregrep --count option prints the count for each file even when it is
567        zero, as does GNU grep. However, pcregrep was also printing all files when
568        --files-with-matches was added. Now, when both options are given, it prints
569        counts only for those files that have at least one match. (GNU grep just
570        prints the file name in this circumstance, but including the count seems
571        more useful - otherwise, why use --count?) Also ensured that the
572        combination -clh just lists non-zero counts, with no names.
573    
574    4.  The long form of the pcregrep -F option was incorrectly implemented as
575        --fixed_strings instead of --fixed-strings. This is an incompatible change,
576        but it seems right to fix it, and I didn't think it was worth preserving
577        the old behaviour.
578    
579    5.  The command line items --regex=pattern and --regexp=pattern were not
580        recognized by pcregrep, which required --regex pattern or --regexp pattern
581        (with a space rather than an '='). The man page documented the '=' forms,
582        which are compatible with GNU grep; these now work.
583    
584    6.  No libpcreposix.pc file was created for pkg-config; there was just
585        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
586    
587    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
588        when UCP support is not needed, by modifying the Python script that
589        generates it from Unicode data files. This should not matter if the module
590        is correctly used as a library, but I received one complaint about 50K of
591        unwanted data. My guess is that the person linked everything into his
592        program rather than using a library. Anyway, it does no harm.
593    
594    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
595        was a minimum greater than 1 for a wide character in a possessive
596        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
597        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
598        character. Chaos in the form of incorrect output or a compiling loop could
599        result.
600    
601    9.  The restrictions on what a pattern can contain when partial matching is
602        requested for pcre_exec() have been removed. All patterns can now be
603        partially matched by this function. In addition, if there are at least two
604        slots in the offset vector, the offset of the earliest inspected character
605        for the match and the offset of the end of the subject are set in them when
606        PCRE_ERROR_PARTIAL is returned.
607    
608    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
609        synonymous with PCRE_PARTIAL, for backwards compatibility, and
610        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
611        and may be more useful for multi-segment matching.
612    
613    11. Partial matching with pcre_exec() is now more intuitive. A partial match
614        used to be given if ever the end of the subject was reached; now it is
615        given only if matching could not proceed because another character was
616        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
617        string "Z", which now yields "no match" instead of "partial match". In the
618        case of pcre_dfa_exec(), "no match" is given if every matching path for the
619        final character ended with (*FAIL).
620    
621    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
622        if the pattern had a "must contain" character that was already found in the
623        earlier partial match, unless partial matching was again requested. For
624        example, with the pattern /dog.(body)?/, the "must contain" character is
625        "g". If the first part-match was for the string "dog", restarting with
626        "sbody" failed. This bug has been fixed.
627    
628    13. The string returned by pcre_dfa_exec() after a partial match has been
629        changed so that it starts at the first inspected character rather than the
630        first character of the match. This makes a difference only if the pattern
631        starts with a lookbehind assertion or \b or \B (\K is not supported by
632        pcre_dfa_exec()). It's an incompatible change, but it makes the two
633        matching functions compatible, and I think it's the right thing to do.
634    
635    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
636        so that the demonstration program is easily available in environments where
637        PCRE has not been installed from source.
638    
639    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
640        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
641        library.
642    
643    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
644        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
645        is not the first non-POSIX option to be added. Clearly some people find
646        these options useful.
647    
648    17. If a caller to the POSIX matching function regexec() passes a non-zero
649        value for nmatch with a NULL value for pmatch, the value of
650        nmatch is forced to zero.
651    
652    18. RunGrepTest did not have a test for the availability of the -u option of
653        the diff command, as RunTest does. It now checks in the same way as
654        RunTest, and also checks for the -b option.
655    
656    19. If an odd number of negated classes containing just a single character
657        interposed, within parentheses, between a forward reference to a named
658        subpattern and the definition of the subpattern, compilation crashed with
659        an internal error, complaining that it could not find the referenced
660        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
661        [The bug was that it was starting one character too far in when skipping
662        over the character class, thus treating the ] as data rather than
663        terminating the class. This meant it could skip too much.]
664    
665    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
666        /g option in pcretest when the pattern contains \K, which makes it possible
667        to have an empty string match not at the start, even when the pattern is
668        anchored. Updated pcretest and pcredemo to use this option.
669    
670    21. If the maximum number of capturing subpatterns in a recursion was greater
671        than the maximum at the outer level, the higher number was returned, but
672        with unset values at the outer level. The correct (outer level) value is
673        now given.
674    
675    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
676        PCRE did not set those parentheses (unlike Perl). I have now found a way to
677        make it do so. The string so far is captured, making this feature
678        compatible with Perl.
679    
680    23. The tests have been re-organized, adding tests 11 and 12, to make it
681        possible to check the Perl 5.10 features against Perl 5.10.
682    
683    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
684        pattern matches a fixed length string. PCRE did not allow this; now it
685        does. Neither allows recursion.
686    
687    25. I finally figured out how to implement a request to provide the minimum
688        length of subject string that was needed in order to match a given pattern.
689        (It was back references and recursion that I had previously got hung up
690        on.) This code has now been added to pcre_study(); it finds a lower bound
691        to the length of subject needed. It is not necessarily the greatest lower
692        bound, but using it to avoid searching strings that are too short does give
693        some useful speed-ups. The value is available to calling programs via
694        pcre_fullinfo().
695    
696    26. While implementing 25, I discovered to my embarrassment that pcretest had
697        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
698        study optimizations had never been tested with that matching function.
699        Oops. What is worse, even when it was passed study data, there was a bug in
700        pcre_dfa_exec() that meant it never actually used it. Double oops. There
701        were also very few tests of studied patterns with pcre_dfa_exec().
702    
703    27. If (?| is used to create subpatterns with duplicate numbers, they are now
704        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
705        on the other side of the coin, they are no longer allowed to have different
706        names, because these cannot be distinguished in PCRE, and this has caused
707        confusion. (This is a difference from Perl.)
708    
709    28. When duplicate subpattern names are present (necessarily with different
710        numbers, as required by 27 above), and a test is made by name in a
711        conditional pattern, either for a subpattern having been matched, or for
712        recursion in such a pattern, all the associated numbered subpatterns are
713        tested, and the overall condition is true if the condition is true for any
714        one of them. This is the way Perl works, and is also more like the way
715        testing by number works.
716    
717    
718    Version 7.9 11-Apr-09
719    ---------------------
720    
721    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
722        (pcretest), all targets were linked against these libraries. This included
723        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
724        libraries. This caused unwanted dependencies to be created. This problem
725        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
726        pcretest is linked with readline.
727    
728    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
729        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
730        moved outside it again, because FALSE and TRUE are already defined in AIX,
731        but BOOL is not.
732    
733    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
734        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
735    
736    4.  The pcregrep documentation said spaces were inserted as well as colons (or
737        hyphens) following file names and line numbers when outputting matching
738        lines. This is not true; no spaces are inserted. I have also clarified the
739        wording for the --colour (or --color) option.
740    
741    5.  In pcregrep, when --colour was used with -o, the list of matching strings
742        was not coloured; this is different to GNU grep, so I have changed it to be
743        the same.
744    
745    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
746        each matching line was coloured. Now it goes on to look for further matches
747        of any of the test patterns, which is the same behaviour as GNU grep.
748    
749    7.  A pattern that could match an empty string could cause pcregrep to loop; it
750        doesn't make sense to accept an empty string match in pcregrep, so I have
751        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
752        seems to be how GNU grep behaves.
753    
754    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
755        start or after a newline", because the conditional assertion was not being
756        correctly handled. The rule now is that both the assertion and what follows
757        in the first alternative must satisfy the test.
758    
759    9.  If auto-callout was enabled in a pattern with a conditional group whose
760        condition was an assertion, PCRE could crash during matching, both with
761        pcre_exec() and pcre_dfa_exec().
762    
763    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
764        used for matching.
765    
766    11. Unicode property support in character classes was not working for
767        characters (bytes) greater than 127 when not in UTF-8 mode.
768    
769    12. Added the -M command line option to pcretest.
770    
771    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
772    
773    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
774    
775    16. Added comments and documentation about mis-use of no_arg in the C++
776        wrapper.
777    
778    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
779        from Martin Jerabek that uses macro names for all relevant character and
780        string constants.
781    
782    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
783        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
784        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
785        these, but not everybody uses configure.
786    
787    19. A conditional group that had only one branch was not being correctly
788        recognized as an item that could match an empty string. This meant that an
789        enclosing group might also not be so recognized, causing infinite looping
790        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
791        with the subject "ab", where knowledge that the repeated group can match
792        nothing is needed in order to break the loop.
793    
794    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
795        exec(), but without supplying a callout function, matching went wrong.
796    
797    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
798        leak if the size of the offset vector was greater than 30. When the vector
799        is smaller, the saved offsets during recursion go onto a local stack
800        vector, but for larger vectors malloc() is used. It was failing to free
801        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
802        error, in fact).
803    
804    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
805        heapframe that is used only when UTF-8 support is enabled. This caused no
806        problem, but was untidy.
807    
808    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
809        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
810        included within another project.
811    
812    24. Steven Van Ingelgem's patches to add more options to the CMake support,
813        slightly modified by me:
814    
815          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
816              not building pcregrep.
817    
818          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
819              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
820    
821    25. Forward references, both numeric and by name, in patterns that made use of
822        duplicate group numbers, could behave incorrectly or give incorrect errors,
823        because when scanning forward to find the reference group, PCRE was not
824        taking into account the duplicate group numbers. A pattern such as
825        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
826    
827    26. Changed a few more instances of "const unsigned char *" to USPTR, making
828        the feature of a custom pointer more persuasive (as requested by a user).
829    
830    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
831        pcretest.c, inside #ifndefs, because it seems they are sometimes already
832        pre-defined.
833    
834    28. Added support for (*UTF8) at the start of a pattern.
835    
836    29. Arrange for flags added by the "release type" setting in CMake to be shown
837        in the configuration summary.
838    
839    
840    Version 7.8 05-Sep-08
841    ---------------------
842    
843    1.  Replaced UCP searching code with optimized version as implemented for Ad
844        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
845        stage table and inline lookup instead of a function, giving speed ups of 2
846        to 5 times on some simple patterns that I tested. Permission was given to
847        distribute the MultiStage2.py script that generates the tables (it's not in
848        the tarball, but is in the Subversion repository).
849    
850    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
851        scripts.
852    
853    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
854        a group with a zero qualifier. The result of the study could be incorrect,
855        or the function might crash, depending on the pattern.
856    
857    4.  Caseless matching was not working for non-ASCII characters in back
858        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
859        It now works when Unicode Property Support is available.
860    
861    5.  In pcretest, an escape such as \x{de} in the data was always generating
862        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
863        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
864        truncation.
865    
866    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
867    
868    7.  Added two (int) casts to pcregrep when printing the difference of two
869        pointers, in case they are 64-bit values.
870    
871    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
872        test 2 if it fails.
873    
874    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
875        and a #define of that name to empty if it is not externally set. This is to
876        allow users of MSVC to set it if necessary.
877    
878    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
879        the convenience functions in the pcre_get.c source file.
880    
881    11. An option change at the start of a pattern that had top-level alternatives
882        could cause overwriting and/or a crash. This command provoked a crash in
883        some environments:
884    
885          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
886    
887        This potential security problem was recorded as CVE-2008-2371.
888    
889    12. For a pattern where the match had to start at the beginning or immediately
890        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
891        pcre_dfa_exec() could read past the end of the passed subject if there was
892        no match. To help with detecting such bugs (e.g. with valgrind), I modified
893        pcretest so that it places the subject at the end of its malloc-ed buffer.
894    
895    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
896        exec() might read past the end of the data buffer in UTF-8 mode.
897    
898    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
899        the data contained the byte 0x85 as part of a UTF-8 character within its
900        first line. This applied both to normal and DFA matching.
901    
902    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
903        /^[^d]*?$/8 failed to match "abc".
904    
905    16. Added a missing copyright notice to pcrecpp_internal.h.
906    
907    17. Make it more clear in the documentation that values returned from
908        pcre_exec() in ovector are byte offsets, not character counts.
909    
910    18. Tidied a few places to stop certain compilers from issuing warnings.
911    
912    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
913        supplied by Stefan Weber. I made a further small update for 7.8 because
914        there is a change of source arrangements: the pcre_searchfuncs.c module is
915        replaced by pcre_ucd.c.
916    
917    
918    Version 7.7 07-May-08
919    ---------------------
920    
921    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
922        a string to a long long, pretend we don't even have a long long." This is
923        done by checking for the strtoq, strtoll, and _strtoi64 functions.
924    
925    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
926        pre-7.6 versions, which defined a global no_arg variable instead of putting
927        it in the RE class. (See also #8 below.)
928    
929    3.  Remove a line of dead code, identified by coverity and reported by Nuno
930        Lopes.
931    
932    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
933    
934        (1) The include/exclude patterns were being applied to the whole pathnames
935            of files, instead of just to the final components.
936    
937        (2) If there was more than one level of directory, the subdirectories were
938            skipped unless they satisfied the include/exclude conditions. This is
939            inconsistent with GNU grep (and could even be seen as contrary to the
940            pcregrep specification - which I improved to make it absolutely clear).
941            The action now is always to scan all levels of directory, and just
942            apply the include/exclude patterns to regular files.
943    
944    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
945        --exclude_dir in the tests to avoid scanning .svn directories.
946    
947    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
948        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
949        doesn't support NULs in patterns.
950    
951    7.  Added some missing "const"s to declarations of static tables in
952        pcre_compile.c and pcre_dfa_exec.c.
953    
954    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
955        caused by fix #2  above. (Subsequently also a second patch to fix the
956        first patch. And a third patch - this was a messy problem.)
957    
958    9.  Applied Craig's patch to remove the use of push_back().
959    
960    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
961        matching function regexec().
962    
963    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
964        which, however, unlike Perl's \g{...}, are subroutine calls, not back
965        references. PCRE supports relative numbers with this syntax (I don't think
966        Oniguruma does).
967    
968    12. Previously, a group with a zero repeat such as (...){0} was completely
969        omitted from the compiled regex. However, this means that if the group
970        was called as a subroutine from elsewhere in the pattern, things went wrong
971        (an internal error was given). Such groups are now left in the compiled
972        pattern, with a new opcode that causes them to be skipped at execution
973        time.
974    
975    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
976        to the way PCRE behaves:
977    
978        (a) A lone ] character is dis-allowed (Perl treats it as data).
979    
980        (b) A back reference to an unmatched subpattern matches an empty string
981            (Perl fails the current match path).
982    
983        (c) A data ] in a character class must be notated as \] because if the
984            first data character in a class is ], it defines an empty class. (In
985            Perl it is not possible to have an empty class.) The empty class []
986            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
987            The negative empty class [^] matches any one character, independently
988            of the DOTALL setting.
989    
990    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
991        non-existent subpattern following a character class starting with ']' and
992        containing () gave an internal compiling error instead of "reference to
993        non-existent subpattern". Fortunately, when the pattern did exist, the
994        compiled code was correct. (When scanning forwards to check for the
995        existencd of the subpattern, it was treating the data ']' as terminating
996        the class, so got the count wrong. When actually compiling, the reference
997        was subsequently set up correctly.)
998    
999    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1000        it was being rejected as not supported by pcre_dfa_exec(), even though
1001        other assertions are supported. I have made pcre_dfa_exec() support
1002        (*FAIL).
1003    
1004    16. The implementation of 13c above involved the invention of a new opcode,
1005        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1006        cannot be changed at match time, I realized I could make a small
1007        improvement to matching performance by compiling OP_ALLANY instead of
1008        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1009        on the OP_ANY path.
1010    
1011    17. Compiling pcretest on Windows with readline support failed without the
1012        following two fixes: (1) Make the unistd.h include conditional on
1013        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1014    
1015    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1016        ncurses library to be included for pcretest when ReadLine support is
1017        requested, but also to allow for it to be overridden. This patch came from
1018        Daniel Bergström.
1019    
1020    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1021        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1022        any errors with the current Unicode tables. Thanks to Peter Kankowski for
1023        spotting this.
1024    
1025    
1026    Version 7.6 28-Jan-08
1027    ---------------------
1028    
1029    1.  A character class containing a very large number of characters with
1030        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1031        overflow.
1032    
1033    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1034        HAVE_LONG_LONG is not defined.
1035    
1036    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1037        bring them up to date and include new features. This patch includes:
1038    
1039        - Fixed PH's badly added libz and libbz2 support.
1040        - Fixed a problem with static linking.
1041        - Added pcredemo. [But later removed - see 7 below.]
1042        - Fixed dftables problem and added an option.
1043        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1044            HAVE_LONG_LONG.
1045        - Added readline support for pcretest.
1046        - Added an listing of the option settings after cmake has run.
1047    
1048    4.  A user submitted a patch to Makefile that makes it easy to create
1049        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1050        Makefile.am that cause it to include this special target, without
1051        affecting anything else. Note that the same mingw target plus all
1052        the other distribution libraries and programs are now supported
1053        when configuring with CMake (see 6 below) instead of with
1054        Configure/Make.
1055    
1056    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1057        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1058        exported in the Windows port". It has not yet been confirmed that the patch
1059        solves the problem, but it does no harm.
1060    
1061    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1062        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1063        with CMake, and also correct the comment about stack recursion.
1064    
1065    7.  Remove the automatic building of pcredemo from the ./configure system and
1066        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1067        of a program that users should build themselves after PCRE is installed, so
1068        building it automatically is not really right. What is more, it gave
1069        trouble in some build environments.
1070    
1071    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1072    
1073    
1074    Version 7.5 10-Jan-08
1075    ---------------------
1076    
1077    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1078        values in parens when parsing an RE using the C++ wrapper."
1079    
1080    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1081        Characters greater than 255 were excluded from the class instead of being
1082        included.
1083    
1084    3.  The same bug as (2) above applied to negated POSIX classes such as
1085        [:^space:].
1086    
1087    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1088        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1089        I have changed it.
1090    
1091    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1092        first named subpattern) and a construct such as (?&a) would reference the
1093        first named subpattern whose name started with "a" (in other words, the
1094        length check was missing). Both these problems are fixed. "Subpattern name
1095        expected" is now given for (?&) (a zero-length name), and this patch also
1096        makes it give the same error for \k'' (previously it complained that that
1097        was a reference to a non-existent subpattern).
1098    
1099    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1100        this is right because (?- can be followed by option settings as well as by
1101        digits. I have, however, made the messages clearer.
1102    
1103    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1104        than the number used in the conditional) now cause a compile-time error.
1105        This is actually not compatible with Perl, which accepts such patterns, but
1106        treats the conditional as always being FALSE (as PCRE used to), but it
1107        seems to me that giving a diagnostic is better.
1108    
1109    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1110        and messages.
1111    
1112    9.  Fix two occurrences of "backslash" in comments that should have been
1113        "backspace".
1114    
1115    10. Remove two redundant lines of code that can never be obeyed (their function
1116        was moved elsewhere).
1117    
1118    11. The program that makes PCRE's Unicode character property table had a bug
1119        which caused it to generate incorrect table entries for sequences of
1120        characters that have the same character type, but are in different scripts.
1121        It amalgamated them into a single range, with the script of the first of
1122        them. In other words, some characters were in the wrong script. There were
1123        thirteen such cases, affecting characters in the following ranges:
1124    
1125          U+002b0 - U+002c1
1126          U+0060c - U+0060d
1127          U+0061e - U+00612
1128          U+0064b - U+0065e
1129          U+0074d - U+0076d
1130          U+01800 - U+01805
1131          U+01d00 - U+01d77
1132          U+01d9b - U+01dbf
1133          U+0200b - U+0200f
1134          U+030fc - U+030fe
1135          U+03260 - U+0327f
1136          U+0fb46 - U+0fbb1
1137          U+10450 - U+1049d
1138    
1139    12. The -o option (show only the matching part of a line) for pcregrep was not
1140        compatible with GNU grep in that, if there was more than one match in a
1141        line, it showed only the first of them. It now behaves in the same way as
1142        GNU grep.
1143    
1144    13. If the -o and -v options were combined for pcregrep, it printed a blank
1145        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1146        does the same. The return code can be used to tell if there were any
1147        non-matching lines.
1148    
1149    14. Added --file-offsets and --line-offsets to pcregrep.
1150    
1151    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1152        infinitely looping recursion. The bug was that positive lookaheads were not
1153        being skipped when checking for a possible empty match (negative lookaheads
1154        and both kinds of lookbehind were skipped).
1155    
1156    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1157        inclusion of <windows.h> to before rather than after the definition of
1158        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1159    
1160    17. Specifying a possessive quantifier with a specific limit for a Unicode
1161        character property caused pcre_compile() to compile bad code, which led at
1162        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1163        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1164        caused the error; without that there was no problem.
1165    
1166    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1167    
1168    19. Added --enable-pcretest-libreadline.
1169    
1170    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1171        RE::GlobalReplace(). As a result, the number of replacements returned was
1172        double what it should be. I removed one of the increments, but Craig sent a
1173        later patch that removed the other one (the right fix) and added unit tests
1174        that check the return values (which was not done before).
1175    
1176    21. Several CMake things:
1177    
1178        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1179            the names libpcre and libpcreposix, not just pcre and pcreposix.
1180    
1181        (2) The above change means that pcretest and pcregrep are now correctly
1182            linked with the newly-built libraries, not previously installed ones.
1183    
1184        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1185    
1186    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1187        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1188        UTF-8 newline character). The key issue is that the pattern starts .*;
1189        this means that the match must be either at the beginning, or after a
1190        newline. The bug was in the code for advancing after a failed match and
1191        checking that the new position followed a newline. It was not taking
1192        account of UTF-8 characters correctly.
1193    
1194    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1195        character classes. PCRE was not treating the sequence [:...:] as a
1196        character class unless the ... were all letters. Perl, however, seems to
1197        allow any characters between [: and :], though of course it rejects as
1198        unknown any "names" that contain non-letters, because all the known class
1199        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1200        for example, whereas PCRE did not - it did not recognize a POSIX character
1201        class. This seemed a bit dangerous, so the code has been changed to be
1202        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1203        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1204        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1205        Perl does, and where it didn't before.
1206    
1207    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1208        Windows environments %n is disabled by default.
1209    
1210    
1211    Version 7.4 21-Sep-07
1212    ---------------------
1213    
1214    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1215        means that a class such as [\s] counted as "explicit reference to CR or
1216        LF". That isn't really right - the whole point of the change was to try to
1217        help when there was an actual mention of one of the two characters. So now
1218        the change happens only if \r or \n (or a literal CR or LF) character is
1219        encountered.
1220    
1221    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1222        of both had grown to the point where there were only 3 bits left.
1223        Fortunately, there was spare space in the data structure, and so I have
1224        moved the internal flags into a new 16-bit field to free up more option
1225        bits.
1226    
1227    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1228        but did not set the internal JCHANGED flag - either of these is enough to
1229        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1230        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1231        start sets both bits.
1232    
1233    4.  Added options (at build time, compile time, exec time) to change \R from
1234        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1235    
1236    5.  doc/pcresyntax.html was missing from the distribution.
1237    
1238    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1239        compatibility, even though it is no longer used.
1240    
1241    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1242        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1243        windows.h file is present (where different names are used). [This was
1244        reversed later after testing - see 16 below.]
1245    
1246    8.  Changed all #include <config.h> to #include "config.h". There were also
1247        some further <pcre.h> cases that I changed to "pcre.h".
1248    
1249    9.  When pcregrep was used with the --colour option, it missed the line ending
1250        sequence off the lines that it output.
1251    
1252    10. It was pointed out to me that arrays of string pointers cause lots of
1253        relocations when a shared library is dynamically loaded. A technique of
1254        using a single long string with a table of offsets can drastically reduce
1255        these. I have refactored PCRE in four places to do this. The result is
1256        dramatic:
1257    
1258          Originally:                          290
1259          After changing UCP table:            187
1260          After changing error message table:   43
1261          After changing table of "verbs"       36
1262          After changing table of Posix names   22
1263    
1264        Thanks to the folks working on Gregex for glib for this insight.
1265    
1266    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1267        unicode-properties was also set.
1268    
1269    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1270    
1271    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1272        checked only for CRLF.
1273    
1274    14. Added casts to pcretest.c to avoid compiler warnings.
1275    
1276    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1277    
1278    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1279        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1280        entirely. This removes changes made in 7 above.
1281    
1282    17. The CMake files have been updated, and there is now more information about
1283        building with CMake in the NON-UNIX-USE document.
1284    
1285    
1286    Version 7.3 28-Aug-07
1287  ---------------------  ---------------------
1288    
1289   1. In the rejigging of the build system that eventually resulted in 7.1, the   1. In the rejigging of the build system that eventually resulted in 7.1, the
# Line 9  Version 7.3 05-Jul-07 Line 1291  Version 7.3 05-Jul-07
1291      brackets there is not right, since it causes compilers to look for an      brackets there is not right, since it causes compilers to look for an
1292      installed pcre.h, not the version that is in the source that is being      installed pcre.h, not the version that is in the source that is being
1293      compiled (which of course may be different). I have changed it back to:      compiled (which of course may be different). I have changed it back to:
1294    
1295        #include "pcre.h"        #include "pcre.h"
1296    
1297      I have a vague recollection that the change was concerned with compiling in      I have a vague recollection that the change was concerned with compiling in
1298      different directories, but in the new build system, that is taken care of      different directories, but in the new build system, that is taken care of
1299      by the VPATH setting the Makefile.      by the VPATH setting the Makefile.
1300    
1301   2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed   2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1302      when the subject happened to end in the byte 0x85 (e.g. if the last      when the subject happened to end in the byte 0x85 (e.g. if the last
1303      character was \x{1ec5}). *Character* 0x85 is one of the "any" newline      character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
# Line 23  Version 7.3 05-Jul-07 Line 1305  Version 7.3 05-Jul-07
1305      of another character. The bug was that, for an unlimited repeat of . in      of another character. The bug was that, for an unlimited repeat of . in
1306      not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by      not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1307      characters when looking for a newline.      characters when looking for a newline.
   
  3. A small performance improvement in the DOTALL UTF-8 mode .* case.  
   
  4. Debugging: adjusted the names of opcodes for different kinds of parentheses  
     in debug output.  
   
  5. Arrange to use "%I64d" instead of "%lld" for long printing in the pcrecpp  
     unittest when running under MinGW.  
   
  6. ESC_K was left out of the EBCDIC table.  
1308    
1309     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1310    
1311     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1312        in debug output.
1313    
1314     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1315        long printing in the pcrecpp unittest when running under MinGW.
1316    
1317     6. ESC_K was left out of the EBCDIC table.
1318    
1319     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1320        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1321        limit also applies to "virtual nesting" when a pattern is recursive, and in
1322        this case 1000 isn't so big. I have been able to remove this limit at the
1323        expense of backing off one optimization in certain circumstances. Normally,
1324        when pcre_exec() would call its internal match() function recursively and
1325        immediately return the result unconditionally, it uses a "tail recursion"
1326        feature to save stack. However, when a subpattern that can match an empty
1327        string has an unlimited repetition quantifier, it no longer makes this
1328        optimization. That gives it a stack frame in which to save the data for
1329        checking that an empty string has been matched. Previously this was taken
1330        from the 1000-entry workspace that had been reserved. So now there is no
1331        explicit limit, but more stack is used.
1332    
1333     8. Applied Daniel's patches to solve problems with the import/export magic
1334        syntax that is required for Windows, and which was going wrong for the
1335        pcreposix and pcrecpp parts of the library. These were overlooked when this
1336        problem was solved for the main library.
1337    
1338     9. There were some crude static tests to avoid integer overflow when computing
1339        the size of patterns that contain repeated groups with explicit upper
1340        limits. As the maximum quantifier is 65535, the maximum group length was
1341        set at 30,000 so that the product of these two numbers did not overflow a
1342        32-bit integer. However, it turns out that people want to use groups that
1343        are longer than 30,000 bytes (though not repeat them that many times).
1344        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1345        made it possible to implement the integer overflow checks in a much more
1346        dynamic way, which I have now done. The artificial limitation on group
1347        length has been removed - we now have only the limit on the total length of
1348        the compiled pattern, which depends on the LINK_SIZE setting.
1349    
1350    10. Fixed a bug in the documentation for get/copy named substring when
1351        duplicate names are permitted. If none of the named substrings are set, the
1352        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1353        empty string.
1354    
1355    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1356        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1357        because the ] is interpreted as the first data character and the
1358        terminating ] is not found. PCRE has been made compatible with Perl in this
1359        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1360        cause memory overwriting.
1361    
1362    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1363        string has been matched (to stop an infinite loop). It was not recognizing
1364        a conditional subpattern that could match an empty string if that
1365        subpattern was within another subpattern. For example, it looped when
1366        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1367        condition was not nested. This bug has been fixed.
1368    
1369    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1370        past the start of the subject in the presence of bytes with the top bit
1371        set, for example "\x8aBCD".
1372    
1373    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1374        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1375    
1376    14. Optimized (?!) to (*FAIL).
1377    
1378    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1379        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1380        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1381        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1382        does: it's just the validity check that is more restrictive.
1383    
1384    16. Inserted checks for integer overflows during escape sequence (backslash)
1385        processing, and also fixed erroneous offset values for syntax errors during
1386        backslash processing.
1387    
1388    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1389        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1390    
1391    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1392        caused an overrun.
1393    
1394    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1395        something other than just ASCII characters) inside a group that had an
1396        unlimited repeat caused a loop at compile time (while checking to see
1397        whether the group could match an empty string).
1398    
1399    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1400        [\P{Any}] did so. (Error in the code for printing property names.)
1401    
1402    21. An orphan \E inside a character class could cause a crash.
1403    
1404    22. A repeated capturing bracket such as (A)? could cause a wild memory
1405        reference during compilation.
1406    
1407    23. There are several functions in pcre_compile() that scan along a compiled
1408        expression for various reasons (e.g. to see if it's fixed length for look
1409        behind). There were bugs in these functions when a repeated \p or \P was
1410        present in the pattern. These operators have additional parameters compared
1411        with \d, etc, and these were not being taken into account when moving along
1412        the compiled data. Specifically:
1413    
1414        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1415            length.
1416    
1417        (b) An item such as \pL+ within a repeated group could cause crashes or
1418            loops.
1419    
1420        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1421            "reference to non-existent subpattern" error.
1422    
1423        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1424    
1425    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1426        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1427    
1428    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1429    
1430    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1431        character were causing crashes (broken optimization).
1432    
1433    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1434        \p or \P) caused a compile-time loop.
1435    
1436    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1437        break. For example, the unstudied pattern [\r\n]A does not match the string
1438        "\r\nA" because change 7.0/46 below moves the current point on by two
1439        characters after failing to match at the start. However, the pattern \nA
1440        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1441        the same is true. There doesn't seem any very clean way out of this, but
1442        what I have chosen to do makes the common cases work: PCRE now takes note
1443        of whether there can be an explicit match for \r or \n anywhere in the
1444        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1445        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1446        pattern has explicit CR or LF references.
1447    
1448    29. Added (*CR) etc for changing newline setting at start of pattern.
1449    
1450    
1451  Version 7.2 19-Jun-07  Version 7.2 19-Jun-07

Legend:
Removed from v.195  
changed lines
  Added in v.609

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12