/[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 553 by ph10, Fri Oct 22 15:57:50 2010 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.00 ??-???-??  Version 8.11 10-Oct-2010
5    ------------------------
6    
7    1.  (*THEN) was not working properly if there were untried alternatives prior
8        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9        backtracked to try for "b" instead of moving to the next alternative branch
10        at the same level (in this case, to look for "c"). The Perl documentation
11        is clear that when (*THEN) is backtracked onto, it goes to the "next
12        alternative in the innermost enclosing group".
13    
14    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
16        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18        (*THEN).
19    
20    3.  If \s appeared in a character class, it removed the VT character from
21        the class, even if it had been included by some previous item, for example
22        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23        of \s, but is part of the POSIX "space" class.)
24    
25    4.  A partial match never returns an empty string (because you can always
26        match an empty string at the end of the subject); however the checking for
27        an empty string was starting at the "start of match" point. This has been
28        changed to the "earliest inspected character" point, because the returned
29        data for a partial match starts at this character. This means that, for
30        example, /(?<=abc)def/ gives a partial match for the subject "abc"
31        (previously it gave "no match").
32    
33    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36        has an implication that the given string is incomplete (because a partial
37        match is preferred over a full match). For this reason, these items now
38        give a partial match in this situation. [Aside: previously, the one case
39        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40        match rather than a full match, which was wrong by the old rules, but is
41        now correct.]
42    
43    
44    Version 8.10 25-Jun-2010
45    ------------------------
46    
47    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
48        THEN.
49    
50    2.  (*ACCEPT) was not working when inside an atomic group.
51    
52    3.  Inside a character class, \B is treated as a literal by default, but
53        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
54        causes the error). The code is unchanged, but I tidied the documentation.
55    
56    4.  Inside a character class, PCRE always treated \R and \X as literals,
57        whereas Perl faults them if its -w option is set. I have changed PCRE so
58        that it faults them when PCRE_EXTRA is set.
59    
60    5.  Added support for \N, which always matches any character other than
61        newline. (It is the same as "." when PCRE_DOTALL is not set.)
62    
63    6.  When compiling pcregrep with newer versions of gcc which may have
64        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
65        declared with attribute warn_unused_result" were given. Just casting the
66        result to (void) does not stop the warnings; a more elaborate fudge is
67        needed. I've used a macro to implement this.
68    
69    7.  Minor change to pcretest.c to avoid a compiler warning.
70    
71    8.  Added four artifical Unicode properties to help with an option to make
72        \s etc use properties (see next item). The new properties are: Xan
73        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
74    
75    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
76        use Unicode properties. (*UCP) at the start of a pattern can be used to set
77        this option. Modified pcretest to add /W to test this facility. Added
78        REG_UCP to make it available via the POSIX interface.
79    
80    10. Added --line-buffered to pcregrep.
81    
82    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
83        studied, and the match started with a letter with a code point greater than
84        127 whose first byte was different to the first byte of the other case of
85        the letter, the other case of this starting letter was not recognized
86        (#976).
87    
88    12. If a pattern that was studied started with a repeated Unicode property
89        test, for example, \p{Nd}+, there was the theoretical possibility of
90        setting up an incorrect bitmap of starting bytes, but fortunately it could
91        not have actually happened in practice until change 8 above was made (it
92        added property types that matched character-matching opcodes).
93    
94    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
95        possible starting bytes for non-anchored patterns.
96    
97    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
98        \R, and also a number of cases that involve Unicode properties, both
99        explicit and implicit when PCRE_UCP is set.
100    
101    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
102        input, it could crash or give wrong results if characters with values
103        greater than 0xc0 were present in the subject string. (Detail: it assumed
104        UTF-8 input when processing these items.)
105    
106    16. Added a lot of (int) casts to avoid compiler warnings in systems where
107        size_t is 64-bit (#991).
108    
109    17. Added a check for running out of memory when PCRE is compiled with
110        --disable-stack-for-recursion (#990).
111    
112    18. If the last data line in a file for pcretest does not have a newline on
113        the end, a newline was missing in the output.
114    
115    19. The default pcre_chartables.c file recognizes only ASCII characters (values
116        less than 128) in its various bitmaps. However, there is a facility for
117        generating tables according to the current locale when PCRE is compiled. It
118        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
119        characters, are recognized by isspace() and therefore were getting set in
120        these tables, and indeed these tables seem to approximate to ISO 8859. This
121        caused a problem in UTF-8 mode when pcre_study() was used to create a list
122        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
123        which of course cannot start UTF-8 characters. I have changed the code so
124        that only real ASCII characters (less than 128) and the correct starting
125        bytes for UTF-8 encodings are set for characters greater than 127 when in
126        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
127        altogether.)
128    
129    20. Added the /T option to pcretest so as to be able to run tests with non-
130        standard character tables, thus making it possible to include the tests
131        used for 19 above in the standard set of tests.
132    
133    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
134        reference to a subpattern the other side of a comment that contains an
135        opening parenthesis caused either an internal compiling error, or a
136        reference to the wrong subpattern.
137    
138    
139    Version 8.02 19-Mar-2010
140    ------------------------
141    
142    1.  The Unicode data tables have been updated to Unicode 5.2.0.
143    
144    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
145        configured.
146    
147    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
148        original author of that file, following a query about its status.
149    
150    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
151        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
152    
153    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
154        quantifier applied to a forward-referencing subroutine call, could compile
155        incorrect code or give the error "internal error: previously-checked
156        referenced subpattern not found".
157    
158    6.  Both MS Visual Studio and Symbian OS have problems with initializing
159        variables to point to external functions. For these systems, therefore,
160        pcre_malloc etc. are now initialized to local functions that call the
161        relevant global functions.
162    
163    7.  There were two entries missing in the vectors called coptable and poptable
164        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
165        I've fixed the data, and added a kludgy way of testing at compile time that
166        the lengths are correct (equal to the number of opcodes).
167    
168    8.  Following on from 7, I added a similar kludge to check the length of the
169        eint vector in pcreposix.c.
170    
171    9.  Error texts for pcre_compile() are held as one long string to avoid too
172        much relocation at load time. To find a text, the string is searched,
173        counting zeros. There was no check for running off the end of the string,
174        which could happen if a new error number was added without updating the
175        string.
176    
177    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
178    
179    11. \K was not working if it appeared in an atomic group or in a group that
180        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
181        \K is "not well defined" if used in an assertion. PCRE now accepts it if
182        the assertion is positive, but not if it is negative.
183    
184    12. Change 11 fortuitously reduced the size of the stack frame used in the
185        "match()" function of pcre_exec.c by one pointer. Forthcoming
186        implementation of support for (*MARK) will need an extra pointer on the
187        stack; I have reserved it now, so that the stack frame size does not
188        decrease.
189    
190    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
191        item in branch that calls a recursion is a subroutine call - as in the
192        second branch in the above example - was incorrectly given the compile-
193        time error "recursive call could loop indefinitely" because pcre_compile()
194        was not correctly checking the subroutine for matching a non-empty string.
195    
196    14. The checks for overrunning compiling workspace could trigger after an
197        overrun had occurred. This is a "should never occur" error, but it can be
198        triggered by pathological patterns such as hundreds of nested parentheses.
199        The checks now trigger 100 bytes before the end of the workspace.
200    
201    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
202    
203    
204    Version 8.01 19-Jan-2010
205    ------------------------
206    
207    1.  If a pattern contained a conditional subpattern with only one branch (in
208        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
209        computed the wrong minimum data length (which is of course zero for such
210        subpatterns). This could cause incorrect "no match" results.
211    
212    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
213        the pattern is reset in the first branch, pcre_compile() failed with
214        "internal error: code overflow at offset...". This happened only when
215        the reset was to the original external option setting. (An optimization
216        abstracts leading options settings into an external setting, which was the
217        cause of this.)
218    
219    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
220        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
221        assertion pattern did not match (meaning that the assertion was true), it
222        was incorrectly treated as false if the SKIP had been reached during the
223        matching. This also applied to assertions used as conditions.
224    
225    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
226        assertion subpattern, including such a pattern used as a condition,
227        unpredictable results occurred, instead of the error return
228        PCRE_ERROR_DFA_UITEM.
229    
230    5.  The C++ GlobalReplace function was not working like Perl for the special
231        situation when an empty string is matched. It now does the fancy magic
232        stuff that is necessary.
233    
234    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
235        removed. (These were left over from very, very early versions of PCRE.)
236    
237    7.  Some cosmetic changes to the code to make life easier when compiling it
238        as part of something else:
239    
240        (a) Change DEBUG to PCRE_DEBUG.
241    
242        (b) In pcre_compile(), rename the member of the "branch_chain" structure
243            called "current" as "current_branch", to prevent a collision with the
244            Linux macro when compiled as a kernel module.
245    
246        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
247            prevent a collision with the Linux macro when compiled as a kernel
248            module.
249    
250    8.  In pcre_compile() there are some checks for integer overflows that used to
251        cast potentially large values to (double). This has been changed to that
252        when building, a check for int64_t is made, and if it is found, it is used
253        instead, thus avoiding the use of floating point arithmetic. (There is no
254        other use of FP in PCRE.) If int64_t is not found, the fallback is to
255        double.
256    
257    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
258        2005 (difference between two addresses compared to an unsigned value).
259    
260    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
261        custom one, because of the following reported problem in Windows:
262    
263          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
264              under Win32.
265          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
266              therefore missing the function definition.
267          - The compiler thus generates a "C" signature for the test function.
268          - The linker fails to find the "C" function.
269          - PCRE fails to configure if asked to do so against libbz2.
270    
271    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
272        messages were output:
273    
274          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
275          rerunning libtoolize, to keep the correct libtool macros in-tree.
276          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
277    
278        I have done both of these things.
279    
280    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
281        most of the time, it *can* run out if it is given a pattern that contains a
282        runaway infinite recursion. I updated the discussion in the pcrestack man
283        page.
284    
285    13. Now that we have gone to the x.xx style of version numbers, the minor
286        version may start with zero. Using 08 or 09 is a bad idea because users
287        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
288        interpreted as invalid octal numbers. I've updated the previous comment in
289        configure.ac, and also added a check that gives an error if 08 or 09 are
290        used.
291    
292    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
293        causing partial matching to fail when the end of the subject matched \W
294        in a UTF-8 pattern where \W was quantified with a minimum of 3.
295    
296    15. There were some discrepancies between the declarations in pcre_internal.h
297        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
298        their definitions. The declarations used "const uschar *" and the
299        definitions used USPTR. Even though USPTR is normally defined as "const
300        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
301        reported that: "This difference in casting confuses some C++ compilers, for
302        example, SunCC recognizes above declarations as different functions and
303        generates broken code for hbpcre." I have changed the declarations to use
304        USPTR.
305    
306    16. GNU libtool is named differently on some systems. The autogen.sh script now
307        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
308        (FreeBSD).
309    
310    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
311        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
312        comment: "Figure out how to create a longlong from a string: strtoll and
313        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
314        instance, but it only takes 2 args instead of 3!"
315    
316    18. A subtle bug concerned with back references has been fixed by a change of
317        specification, with a corresponding code fix. A pattern such as
318        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
319        refers, was giving matches when it shouldn't. For example, xa=xaaa would
320        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
321        same bug. Such groups have to be quantified to be useful, or contained
322        inside another quantified group. (If there's no repetition, the reference
323        can never match.) The problem arises because, having left the group and
324        moved on to the rest of the pattern, a later failure that backtracks into
325        the group uses the captured value from the final iteration of the group
326        rather than the correct earlier one. I have fixed this in PCRE by forcing
327        any group that contains a reference to itself to be an atomic group; that
328        is, there cannot be any backtracking into it once it has completed. This is
329        similar to recursive and subroutine calls.
330    
331    
332    Version 8.00 19-Oct-09
333  ----------------------  ----------------------
334    
335  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
336      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
337      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
338      error.      error.
339    
340  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,
341      "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
342      in a Windows environment.      in a Windows environment.
343    
344  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
345      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
346      --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
347      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
348      prints the file name in this circumstance, but including the count seems      prints the file name in this circumstance, but including the count seems
349      more useful - otherwise, why use --count?) Also ensured that the      more useful - otherwise, why use --count?) Also ensured that the
350      combination -clh just lists non-zero counts, with no names.      combination -clh just lists non-zero counts, with no names.
351    
352  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
353      --fixed_strings instead of --fixed-strings. This is an incompatible change,      --fixed_strings instead of --fixed-strings. This is an incompatible change,
354      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
355      the old behaviour.      the old behaviour.
356    
357  5.  The command line items --regex=pattern and --regexp=pattern were not  5.  The command line items --regex=pattern and --regexp=pattern were not
358      recognized by pcregrep, which required --regex pattern or --regexp pattern      recognized by pcregrep, which required --regex pattern or --regexp pattern
359      (with a space rather than an '='). The man page documented the '=' forms,      (with a space rather than an '='). The man page documented the '=' forms,
360      which are compatible with GNU grep; these now work.      which are compatible with GNU grep; these now work.
361    
362  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
363      libpcre.pc and libpcrecpp.pc. The omission has been rectified.      libpcre.pc and libpcrecpp.pc. The omission has been rectified.
364    
365  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
366      when UCP support is not needed, by modifying the Python script that      when UCP support is not needed, by modifying the Python script that
367      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
368      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
369      unwanted data. My guess is that the person linked everything into his      unwanted data. My guess is that the person linked everything into his
370      program rather than using a library. Anyway, it does no harm.      program rather than using a library. Anyway, it does no harm.
371    
372  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
373      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
374      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
375      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
376      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
377      result.      result.
378    
379  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
380      requested for pcre_exec() have been removed. All patterns can now be      requested for pcre_exec() have been removed. All patterns can now be
381      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
382      slots in the offset vector, the offset of the earliest inspected character      slots in the offset vector, the offset of the earliest inspected character
383      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
384      PCRE_ERROR_PARTIAL is returned.      PCRE_ERROR_PARTIAL is returned.
385    
386  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
387      synonymous with PCRE_PARTIAL, for backwards compatibility, and      synonymous with PCRE_PARTIAL, for backwards compatibility, and
388      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,
389      and may be more useful for multi-segment matching, especially with      and may be more useful for multi-segment matching.
390      pcre_exec().  
391    11. Partial matching with pcre_exec() is now more intuitive. A partial match
392  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
393      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
394      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
395      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
396      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
397      case of pcre_dfa_exec(), "no match" is given if every matching path for the      final character ended with (*FAIL).
398      final character ended with (*FAIL).  
   
399  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
400      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
401      earlier partial match, unless partial matching was again requested. For      earlier partial match, unless partial matching was again requested. For
402      example, with the pattern /dog.(body)?/, the "must contain" character is      example, with the pattern /dog.(body)?/, the "must contain" character is
403      "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
404      "sbody" failed. This bug has been fixed.      "sbody" failed. This bug has been fixed.
405    
406  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
407      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
408      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
409      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
410      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
411      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.
412    
413  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,
414      so that the demonstration program is easily available in environments where      so that the demonstration program is easily available in environments where
415      PCRE has not been installed from source.      PCRE has not been installed from source.
416    
417  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,
418      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
419      library.      library.
420    
421  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.
422      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
423      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
424      these options useful.      these options useful.
425    
426  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
427      value for nmatch with a NULL value for pmatch, the value of      value for nmatch with a NULL value for pmatch, the value of
428      nmatch is forced to zero.      nmatch is forced to zero.
429    
430  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
431      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
432      RunTest, and also checks for the -b option.      RunTest, and also checks for the -b option.
433    
434  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
435      interposed, within parentheses, between a forward reference to a named      interposed, within parentheses, between a forward reference to a named
436      subpattern and the definition of the subpattern, compilation crashed with      subpattern and the definition of the subpattern, compilation crashed with
437      an internal error, complaining that it could not find the referenced      an internal error, complaining that it could not find the referenced
438      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
439      [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
440      over the character class, thus treating the ] as data rather than      over the character class, thus treating the ] as data rather than
441      terminating the class. This meant it could skip too much.]      terminating the class. This meant it could skip too much.]
442    
443  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
444      /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
445      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
446      anchored. Updated pcretest and pcredemo to use this option.      anchored. Updated pcretest and pcredemo to use this option.
447    
448  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
449      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
450      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
451      now given.      now given.
452    
453  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
454      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
455      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
456      compatible with Perl.      compatible with Perl.
457    
458  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
459      possible to check the Perl 5.10 features against Perl 5.10.      possible to check the Perl 5.10 features against Perl 5.10.
460    
461  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
462      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
463      does. Neither allows recursion.      does. Neither allows recursion.
464    
465    25. I finally figured out how to implement a request to provide the minimum
466        length of subject string that was needed in order to match a given pattern.
467        (It was back references and recursion that I had previously got hung up
468        on.) This code has now been added to pcre_study(); it finds a lower bound
469        to the length of subject needed. It is not necessarily the greatest lower
470        bound, but using it to avoid searching strings that are too short does give
471        some useful speed-ups. The value is available to calling programs via
472        pcre_fullinfo().
473    
474    26. While implementing 25, I discovered to my embarrassment that pcretest had
475        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
476        study optimizations had never been tested with that matching function.
477        Oops. What is worse, even when it was passed study data, there was a bug in
478        pcre_dfa_exec() that meant it never actually used it. Double oops. There
479        were also very few tests of studied patterns with pcre_dfa_exec().
480    
481    27. If (?| is used to create subpatterns with duplicate numbers, they are now
482        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
483        on the other side of the coin, they are no longer allowed to have different
484        names, because these cannot be distinguished in PCRE, and this has caused
485        confusion. (This is a difference from Perl.)
486    
487    28. When duplicate subpattern names are present (necessarily with different
488        numbers, as required by 27 above), and a test is made by name in a
489        conditional pattern, either for a subpattern having been matched, or for
490        recursion in such a pattern, all the associated numbered subpatterns are
491        tested, and the overall condition is true if the condition is true for any
492        one of them. This is the way Perl works, and is also more like the way
493        testing by number works.
494    
495    
496  Version 7.9 11-Apr-09  Version 7.9 11-Apr-09
497  ---------------------  ---------------------

Legend:
Removed from v.454  
changed lines
  Added in v.553

  ViewVC Help
Powered by ViewVC 1.1.5