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

Diff of /code/trunk/ChangeLog

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

revision 454 by ph10, Tue Sep 22 09:42:11 2009 UTC revision 518 by ph10, Tue May 18 15:47:01 2010 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.00 ??-???-??  Version 8.10 03 May-2010
5    ------------------------
6    
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
9    
10    2.  (*ACCEPT) was not working when inside an atomic group.
11    
12    3.  Inside a character class, \B is treated as a literal by default, but
13        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14        causes the error). The code is unchanged, but I tidied the documentation.
15    
16    4.  Inside a character class, PCRE always treated \R and \X as literals,
17        whereas Perl faults them if its -w option is set. I have changed PCRE so
18        that it faults them when PCRE_EXTRA is set.
19    
20    5.  Added support for \N, which always matches any character other than
21        newline. (It is the same as "." when PCRE_DOTALL is not set.)
22    
23    6.  When compiling pcregrep with newer versions of gcc which may have
24        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25        declared with attribute warn_unused_result" were given. Just casting the
26        result to (void) does not stop the warnings; a more elaborate fudge is
27        needed. I've used a macro to implement this.
28    
29    7.  Minor change to pcretest.c to avoid a compiler warning.
30    
31    8.  Added four artifical Unicode properties to help with an option to make
32        \s etc use properties (see next item). The new properties are: Xan
33        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34    
35    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36        use Unicode properties. (*UCP) at the start of a pattern can be used to set
37        this option. Modified pcretest to add /W to test this facility. Added
38        REG_UCP to make it available via the POSIX interface.
39    
40    
41    Version 8.02 19-Mar-2010
42    ------------------------
43    
44    1.  The Unicode data tables have been updated to Unicode 5.2.0.
45    
46    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
47        configured.
48    
49    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
50        original author of that file, following a query about its status.
51    
52    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
53        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
54    
55    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
56        quantifier applied to a forward-referencing subroutine call, could compile
57        incorrect code or give the error "internal error: previously-checked
58        referenced subpattern not found".
59    
60    6.  Both MS Visual Studio and Symbian OS have problems with initializing
61        variables to point to external functions. For these systems, therefore,
62        pcre_malloc etc. are now initialized to local functions that call the
63        relevant global functions.
64    
65    7.  There were two entries missing in the vectors called coptable and poptable
66        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
67        I've fixed the data, and added a kludgy way of testing at compile time that
68        the lengths are correct (equal to the number of opcodes).
69    
70    8.  Following on from 7, I added a similar kludge to check the length of the
71        eint vector in pcreposix.c.
72    
73    9.  Error texts for pcre_compile() are held as one long string to avoid too
74        much relocation at load time. To find a text, the string is searched,
75        counting zeros. There was no check for running off the end of the string,
76        which could happen if a new error number was added without updating the
77        string.
78    
79    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
80    
81    11. \K was not working if it appeared in an atomic group or in a group that
82        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
83        \K is "not well defined" if used in an assertion. PCRE now accepts it if
84        the assertion is positive, but not if it is negative.
85    
86    12. Change 11 fortuitously reduced the size of the stack frame used in the
87        "match()" function of pcre_exec.c by one pointer. Forthcoming
88        implementation of support for (*MARK) will need an extra pointer on the
89        stack; I have reserved it now, so that the stack frame size does not
90        decrease.
91    
92    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
93        item in branch that calls a recursion is a subroutine call - as in the
94        second branch in the above example - was incorrectly given the compile-
95        time error "recursive call could loop indefinitely" because pcre_compile()
96        was not correctly checking the subroutine for matching a non-empty string.
97    
98    14. The checks for overrunning compiling workspace could trigger after an
99        overrun had occurred. This is a "should never occur" error, but it can be
100        triggered by pathological patterns such as hundreds of nested parentheses.
101        The checks now trigger 100 bytes before the end of the workspace.
102    
103    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
104    
105    
106    Version 8.01 19-Jan-2010
107    ------------------------
108    
109    1.  If a pattern contained a conditional subpattern with only one branch (in
110        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
111        computed the wrong minimum data length (which is of course zero for such
112        subpatterns). This could cause incorrect "no match" results.
113    
114    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
115        the pattern is reset in the first branch, pcre_compile() failed with
116        "internal error: code overflow at offset...". This happened only when
117        the reset was to the original external option setting. (An optimization
118        abstracts leading options settings into an external setting, which was the
119        cause of this.)
120    
121    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
122        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
123        assertion pattern did not match (meaning that the assertion was true), it
124        was incorrectly treated as false if the SKIP had been reached during the
125        matching. This also applied to assertions used as conditions.
126    
127    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
128        assertion subpattern, including such a pattern used as a condition,
129        unpredictable results occurred, instead of the error return
130        PCRE_ERROR_DFA_UITEM.
131    
132    5.  The C++ GlobalReplace function was not working like Perl for the special
133        situation when an empty string is matched. It now does the fancy magic
134        stuff that is necessary.
135    
136    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
137        removed. (These were left over from very, very early versions of PCRE.)
138    
139    7.  Some cosmetic changes to the code to make life easier when compiling it
140        as part of something else:
141    
142        (a) Change DEBUG to PCRE_DEBUG.
143    
144        (b) In pcre_compile(), rename the member of the "branch_chain" structure
145            called "current" as "current_branch", to prevent a collision with the
146            Linux macro when compiled as a kernel module.
147    
148        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
149            prevent a collision with the Linux macro when compiled as a kernel
150            module.
151    
152    8.  In pcre_compile() there are some checks for integer overflows that used to
153        cast potentially large values to (double). This has been changed to that
154        when building, a check for int64_t is made, and if it is found, it is used
155        instead, thus avoiding the use of floating point arithmetic. (There is no
156        other use of FP in PCRE.) If int64_t is not found, the fallback is to
157        double.
158    
159    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
160        2005 (difference between two addresses compared to an unsigned value).
161    
162    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
163        custom one, because of the following reported problem in Windows:
164    
165          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
166              under Win32.
167          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
168              therefore missing the function definition.
169          - The compiler thus generates a "C" signature for the test function.
170          - The linker fails to find the "C" function.
171          - PCRE fails to configure if asked to do so against libbz2.
172    
173    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
174        messages were output:
175    
176          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
177          rerunning libtoolize, to keep the correct libtool macros in-tree.
178          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
179    
180        I have done both of these things.
181    
182    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
183        most of the time, it *can* run out if it is given a pattern that contains a
184        runaway infinite recursion. I updated the discussion in the pcrestack man
185        page.
186    
187    13. Now that we have gone to the x.xx style of version numbers, the minor
188        version may start with zero. Using 08 or 09 is a bad idea because users
189        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
190        interpreted as invalid octal numbers. I've updated the previous comment in
191        configure.ac, and also added a check that gives an error if 08 or 09 are
192        used.
193    
194    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
195        causing partial matching to fail when the end of the subject matched \W
196        in a UTF-8 pattern where \W was quantified with a minimum of 3.
197    
198    15. There were some discrepancies between the declarations in pcre_internal.h
199        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
200        their definitions. The declarations used "const uschar *" and the
201        definitions used USPTR. Even though USPTR is normally defined as "const
202        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
203        reported that: "This difference in casting confuses some C++ compilers, for
204        example, SunCC recognizes above declarations as different functions and
205        generates broken code for hbpcre." I have changed the declarations to use
206        USPTR.
207    
208    16. GNU libtool is named differently on some systems. The autogen.sh script now
209        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
210        (FreeBSD).
211    
212    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
213        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
214        comment: "Figure out how to create a longlong from a string: strtoll and
215        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
216        instance, but it only takes 2 args instead of 3!"
217    
218    18. A subtle bug concerned with back references has been fixed by a change of
219        specification, with a corresponding code fix. A pattern such as
220        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
221        refers, was giving matches when it shouldn't. For example, xa=xaaa would
222        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
223        same bug. Such groups have to be quantified to be useful, or contained
224        inside another quantified group. (If there's no repetition, the reference
225        can never match.) The problem arises because, having left the group and
226        moved on to the rest of the pattern, a later failure that backtracks into
227        the group uses the captured value from the final iteration of the group
228        rather than the correct earlier one. I have fixed this in PCRE by forcing
229        any group that contains a reference to itself to be an atomic group; that
230        is, there cannot be any backtracking into it once it has completed. This is
231        similar to recursive and subroutine calls.
232    
233    
234    Version 8.00 19-Oct-09
235  ----------------------  ----------------------
236    
237  1.  The table for translating pcre_compile() error codes into POSIX error codes  1.  The table for translating pcre_compile() error codes into POSIX error codes
238      was out-of-date, and there was no check on the pcre_compile() error code      was out-of-date, and there was no check on the pcre_compile() error code
239      being within the table. This could lead to an OK return being given in      being within the table. This could lead to an OK return being given in
240      error.      error.
241    
242  2.  Changed the call to open a subject file in pcregrep from fopen(pathname,  2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
243      "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests      "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
244      in a Windows environment.      in a Windows environment.
245    
246  3.  The pcregrep --count option prints the count for each file even when it is  3.  The pcregrep --count option prints the count for each file even when it is
247      zero, as does GNU grep. However, pcregrep was also printing all files when      zero, as does GNU grep. However, pcregrep was also printing all files when
248      --files-with-matches was added. Now, when both options are given, it prints      --files-with-matches was added. Now, when both options are given, it prints
249      counts only for those files that have at least one match. (GNU grep just      counts only for those files that have at least one match. (GNU grep just
250      prints the file name in this circumstance, but including the count seems      prints the file name in this circumstance, but including the count seems
251      more useful - otherwise, why use --count?) Also ensured that the      more useful - otherwise, why use --count?) Also ensured that the
252      combination -clh just lists non-zero counts, with no names.      combination -clh just lists non-zero counts, with no names.
253    
254  4.  The long form of the pcregrep -F option was incorrectly implemented as  4.  The long form of the pcregrep -F option was incorrectly implemented as
255      --fixed_strings instead of --fixed-strings. This is an incompatible change,      --fixed_strings instead of --fixed-strings. This is an incompatible change,
256      but it seems right to fix it, and I didn't think it was worth preserving      but it seems right to fix it, and I didn't think it was worth preserving
257      the old behaviour.      the old behaviour.
258    
259  5.  The command line items --regex=pattern and --regexp=pattern were not  5.  The command line items --regex=pattern and --regexp=pattern were not
260      recognized by pcregrep, which required --regex pattern or --regexp pattern      recognized by pcregrep, which required --regex pattern or --regexp pattern
261      (with a space rather than an '='). The man page documented the '=' forms,      (with a space rather than an '='). The man page documented the '=' forms,
262      which are compatible with GNU grep; these now work.      which are compatible with GNU grep; these now work.
263    
264  6.  No libpcreposix.pc file was created for pkg-config; there was just  6.  No libpcreposix.pc file was created for pkg-config; there was just
265      libpcre.pc and libpcrecpp.pc. The omission has been rectified.      libpcre.pc and libpcrecpp.pc. The omission has been rectified.
266    
267  7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size  7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
268      when UCP support is not needed, by modifying the Python script that      when UCP support is not needed, by modifying the Python script that
269      generates it from Unicode data files. This should not matter if the module      generates it from Unicode data files. This should not matter if the module
270      is correctly used as a library, but I received one complaint about 50K of      is correctly used as a library, but I received one complaint about 50K of
271      unwanted data. My guess is that the person linked everything into his      unwanted data. My guess is that the person linked everything into his
272      program rather than using a library. Anyway, it does no harm.      program rather than using a library. Anyway, it does no harm.
273    
274  8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger  8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
275      was a minimum greater than 1 for a wide character in a possessive      was a minimum greater than 1 for a wide character in a possessive
276      repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8      repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
277      which had an unlimited repeat of a nested, fixed maximum repeat of a wide      which had an unlimited repeat of a nested, fixed maximum repeat of a wide
278      character. Chaos in the form of incorrect output or a compiling loop could      character. Chaos in the form of incorrect output or a compiling loop could
279      result.      result.
280    
281  9.  The restrictions on what a pattern can contain when partial matching is  9.  The restrictions on what a pattern can contain when partial matching is
282      requested for pcre_exec() have been removed. All patterns can now be      requested for pcre_exec() have been removed. All patterns can now be
283      partially matched by this function. In addition, if there are at least two      partially matched by this function. In addition, if there are at least two
284      slots in the offset vector, the offset of the earliest inspected character      slots in the offset vector, the offset of the earliest inspected character
285      for the match and the offset of the end of the subject are set in them when      for the match and the offset of the end of the subject are set in them when
286      PCRE_ERROR_PARTIAL is returned.      PCRE_ERROR_PARTIAL is returned.
287    
288  10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is  10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
289      synonymous with PCRE_PARTIAL, for backwards compatibility, and      synonymous with PCRE_PARTIAL, for backwards compatibility, and
290      PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,      PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
291      and may be more useful for multi-segment matching, especially with      and may be more useful for multi-segment matching.
292      pcre_exec().  
293    11. Partial matching with pcre_exec() is now more intuitive. A partial match
294  11. Partial matching with pcre_exec() is now more intuitive. A partial match      used to be given if ever the end of the subject was reached; now it is
295      used to be given if ever the end of the subject was reached; now it is      given only if matching could not proceed because another character was
296      given only if matching could not proceed because another character was      needed. This makes a difference in some odd cases such as Z(*FAIL) with the
297      needed. This makes a difference in some odd cases such as Z(*FAIL) with the      string "Z", which now yields "no match" instead of "partial match". In the
298      string "Z", which now yields "no match" instead of "partial match". In the      case of pcre_dfa_exec(), "no match" is given if every matching path for the
299      case of pcre_dfa_exec(), "no match" is given if every matching path for the      final character ended with (*FAIL).
300      final character ended with (*FAIL).  
   
301  12. Restarting a match using pcre_dfa_exec() after a partial match did not work  12. Restarting a match using pcre_dfa_exec() after a partial match did not work
302      if the pattern had a "must contain" character that was already found in the      if the pattern had a "must contain" character that was already found in the
303      earlier partial match, unless partial matching was again requested. For      earlier partial match, unless partial matching was again requested. For
304      example, with the pattern /dog.(body)?/, the "must contain" character is      example, with the pattern /dog.(body)?/, the "must contain" character is
305      "g". If the first part-match was for the string "dog", restarting with      "g". If the first part-match was for the string "dog", restarting with
306      "sbody" failed. This bug has been fixed.      "sbody" failed. This bug has been fixed.
307    
308  13. The string returned by pcre_dfa_exec() after a partial match has been  13. The string returned by pcre_dfa_exec() after a partial match has been
309      changed so that it starts at the first inspected character rather than the      changed so that it starts at the first inspected character rather than the
310      first character of the match. This makes a difference only if the pattern      first character of the match. This makes a difference only if the pattern
311      starts with a lookbehind assertion or \b or \B (\K is not supported by      starts with a lookbehind assertion or \b or \B (\K is not supported by
312      pcre_dfa_exec()). It's an incompatible change, but it makes the two      pcre_dfa_exec()). It's an incompatible change, but it makes the two
313      matching functions compatible, and I think it's the right thing to do.      matching functions compatible, and I think it's the right thing to do.
314    
315  14. Added a pcredemo man page, created automatically from the pcredemo.c file,  14. Added a pcredemo man page, created automatically from the pcredemo.c file,
316      so that the demonstration program is easily available in environments where      so that the demonstration program is easily available in environments where
317      PCRE has not been installed from source.      PCRE has not been installed from source.
318    
319  15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,  15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
320      libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared      libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
321      library.      library.
322    
323  16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.  16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
324      It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it      It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
325      is not the first non-POSIX option to be added. Clearly some people find      is not the first non-POSIX option to be added. Clearly some people find
326      these options useful.      these options useful.
327    
328  17. If a caller to the POSIX matching function regexec() passes a non-zero  17. If a caller to the POSIX matching function regexec() passes a non-zero
329      value for nmatch with a NULL value for pmatch, the value of      value for nmatch with a NULL value for pmatch, the value of
330      nmatch is forced to zero.      nmatch is forced to zero.
331    
332  18. RunGrepTest did not have a test for the availability of the -u option of  18. RunGrepTest did not have a test for the availability of the -u option of
333      the diff command, as RunTest does. It now checks in the same way as      the diff command, as RunTest does. It now checks in the same way as
334      RunTest, and also checks for the -b option.      RunTest, and also checks for the -b option.
335    
336  19. If an odd number of negated classes containing just a single character  19. If an odd number of negated classes containing just a single character
337      interposed, within parentheses, between a forward reference to a named      interposed, within parentheses, between a forward reference to a named
338      subpattern and the definition of the subpattern, compilation crashed with      subpattern and the definition of the subpattern, compilation crashed with
339      an internal error, complaining that it could not find the referenced      an internal error, complaining that it could not find the referenced
340      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
341      [The bug was that it was starting one character too far in when skipping      [The bug was that it was starting one character too far in when skipping
342      over the character class, thus treating the ] as data rather than      over the character class, thus treating the ] as data rather than
343      terminating the class. This meant it could skip too much.]      terminating the class. This meant it could skip too much.]
344    
345  20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the  20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
346      /g option in pcretest when the pattern contains \K, which makes it possible      /g option in pcretest when the pattern contains \K, which makes it possible
347      to have an empty string match not at the start, even when the pattern is      to have an empty string match not at the start, even when the pattern is
348      anchored. Updated pcretest and pcredemo to use this option.      anchored. Updated pcretest and pcredemo to use this option.
349    
350  21. If the maximum number of capturing subpatterns in a recursion was greater  21. If the maximum number of capturing subpatterns in a recursion was greater
351      than the maximum at the outer level, the higher number was returned, but      than the maximum at the outer level, the higher number was returned, but
352      with unset values at the outer level. The correct (outer level) value is      with unset values at the outer level. The correct (outer level) value is
353      now given.      now given.
354    
355  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
356      PCRE did not set those parentheses (unlike Perl). I have now found a way to      PCRE did not set those parentheses (unlike Perl). I have now found a way to
357      make it do so. The string so far is captured, making this feature      make it do so. The string so far is captured, making this feature
358      compatible with Perl.      compatible with Perl.
359    
360  23. The tests have been re-organized, adding tests 11 and 12, to make it  23. The tests have been re-organized, adding tests 11 and 12, to make it
361      possible to check the Perl 5.10 features against Perl 5.10.      possible to check the Perl 5.10 features against Perl 5.10.
362    
363  24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine  24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
364      pattern matches a fixed length string. PCRE did not allow this; now it      pattern matches a fixed length string. PCRE did not allow this; now it
365      does. Neither allows recursion.      does. Neither allows recursion.
366    
367    25. I finally figured out how to implement a request to provide the minimum
368        length of subject string that was needed in order to match a given pattern.
369        (It was back references and recursion that I had previously got hung up
370        on.) This code has now been added to pcre_study(); it finds a lower bound
371        to the length of subject needed. It is not necessarily the greatest lower
372        bound, but using it to avoid searching strings that are too short does give
373        some useful speed-ups. The value is available to calling programs via
374        pcre_fullinfo().
375    
376    26. While implementing 25, I discovered to my embarrassment that pcretest had
377        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
378        study optimizations had never been tested with that matching function.
379        Oops. What is worse, even when it was passed study data, there was a bug in
380        pcre_dfa_exec() that meant it never actually used it. Double oops. There
381        were also very few tests of studied patterns with pcre_dfa_exec().
382    
383    27. If (?| is used to create subpatterns with duplicate numbers, they are now
384        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
385        on the other side of the coin, they are no longer allowed to have different
386        names, because these cannot be distinguished in PCRE, and this has caused
387        confusion. (This is a difference from Perl.)
388    
389    28. When duplicate subpattern names are present (necessarily with different
390        numbers, as required by 27 above), and a test is made by name in a
391        conditional pattern, either for a subpattern having been matched, or for
392        recursion in such a pattern, all the associated numbered subpatterns are
393        tested, and the overall condition is true if the condition is true for any
394        one of them. This is the way Perl works, and is also more like the way
395        testing by number works.
396    
397    
398  Version 7.9 11-Apr-09  Version 7.9 11-Apr-09
399  ---------------------  ---------------------

Legend:
Removed from v.454  
changed lines
  Added in v.518

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12