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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.9 xx-xxx-09  Version 8.02 01-Mar-2010
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 5.2.0.
9    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10        configured.
12    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
13        original author of that file, following a query about its status.
15    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
16        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
19    Version 8.01 19-Jan-2010
20    ------------------------
22    1.  If a pattern contained a conditional subpattern with only one branch (in
23        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
24        computed the wrong minimum data length (which is of course zero for such
25        subpatterns). This could cause incorrect "no match" results.
27    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
28        the pattern is reset in the first branch, pcre_compile() failed with
29        "internal error: code overflow at offset...". This happened only when
30        the reset was to the original external option setting. (An optimization
31        abstracts leading options settings into an external setting, which was the
32        cause of this.)
34    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
35        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
36        assertion pattern did not match (meaning that the assertion was true), it
37        was incorrectly treated as false if the SKIP had been reached during the
38        matching. This also applied to assertions used as conditions.
40    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
41        assertion subpattern, including such a pattern used as a condition,
42        unpredictable results occurred, instead of the error return
45    5.  The C++ GlobalReplace function was not working like Perl for the special
46        situation when an empty string is matched. It now does the fancy magic
47        stuff that is necessary.
49    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
50        removed. (These were left over from very, very early versions of PCRE.)
52    7.  Some cosmetic changes to the code to make life easier when compiling it
53        as part of something else:
55        (a) Change DEBUG to PCRE_DEBUG.
57        (b) In pcre_compile(), rename the member of the "branch_chain" structure
58            called "current" as "current_branch", to prevent a collision with the
59            Linux macro when compiled as a kernel module.
61        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
62            prevent a collision with the Linux macro when compiled as a kernel
63            module.
65    8.  In pcre_compile() there are some checks for integer overflows that used to
66        cast potentially large values to (double). This has been changed to that
67        when building, a check for int64_t is made, and if it is found, it is used
68        instead, thus avoiding the use of floating point arithmetic. (There is no
69        other use of FP in PCRE.) If int64_t is not found, the fallback is to
70        double.
72    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
73        2005 (difference between two addresses compared to an unsigned value).
75    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
76        custom one, because of the following reported problem in Windows:
78          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
79              under Win32.
80          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
81              therefore missing the function definition.
82          - The compiler thus generates a "C" signature for the test function.
83          - The linker fails to find the "C" function.
84          - PCRE fails to configure if asked to do so against libbz2.
86    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
87        messages were output:
89          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
90          rerunning libtoolize, to keep the correct libtool macros in-tree.
91          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
93        I have done both of these things.
95    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
96        most of the time, it *can* run out if it is given a pattern that contains a
97        runaway infinite recursion. I updated the discussion in the pcrestack man
98        page.
100    13. Now that we have gone to the x.xx style of version numbers, the minor
101        version may start with zero. Using 08 or 09 is a bad idea because users
102        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
103        interpreted as invalid octal numbers. I've updated the previous comment in
104        configure.ac, and also added a check that gives an error if 08 or 09 are
105        used.
107    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
108        causing partial matching to fail when the end of the subject matched \W
109        in a UTF-8 pattern where \W was quantified with a minimum of 3.
111    15. There were some discrepancies between the declarations in pcre_internal.h
112        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
113        their definitions. The declarations used "const uschar *" and the
114        definitions used USPTR. Even though USPTR is normally defined as "const
115        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
116        reported that: "This difference in casting confuses some C++ compilers, for
117        example, SunCC recognizes above declarations as different functions and
118        generates broken code for hbpcre." I have changed the declarations to use
119        USPTR.
121    16. GNU libtool is named differently on some systems. The autogen.sh script now
122        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
123        (FreeBSD).
125    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
126        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
127        comment: "Figure out how to create a longlong from a string: strtoll and
128        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
129        instance, but it only takes 2 args instead of 3!"
131    18. A subtle bug concerned with back references has been fixed by a change of
132        specification, with a corresponding code fix. A pattern such as
133        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
134        refers, was giving matches when it shouldn't. For example, xa=xaaa would
135        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
136        same bug. Such groups have to be quantified to be useful, or contained
137        inside another quantified group. (If there's no repetition, the reference
138        can never match.) The problem arises because, having left the group and
139        moved on to the rest of the pattern, a later failure that backtracks into
140        the group uses the captured value from the final iteration of the group
141        rather than the correct earlier one. I have fixed this in PCRE by forcing
142        any group that contains a reference to itself to be an atomic group; that
143        is, there cannot be any backtracking into it once it has completed. This is
144        similar to recursive and subroutine calls.
147    Version 8.00 19-Oct-09
148    ----------------------
150    1.  The table for translating pcre_compile() error codes into POSIX error codes
151        was out-of-date, and there was no check on the pcre_compile() error code
152        being within the table. This could lead to an OK return being given in
153        error.
155    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
156        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
157        in a Windows environment.
159    3.  The pcregrep --count option prints the count for each file even when it is
160        zero, as does GNU grep. However, pcregrep was also printing all files when
161        --files-with-matches was added. Now, when both options are given, it prints
162        counts only for those files that have at least one match. (GNU grep just
163        prints the file name in this circumstance, but including the count seems
164        more useful - otherwise, why use --count?) Also ensured that the
165        combination -clh just lists non-zero counts, with no names.
167    4.  The long form of the pcregrep -F option was incorrectly implemented as
168        --fixed_strings instead of --fixed-strings. This is an incompatible change,
169        but it seems right to fix it, and I didn't think it was worth preserving
170        the old behaviour.
172    5.  The command line items --regex=pattern and --regexp=pattern were not
173        recognized by pcregrep, which required --regex pattern or --regexp pattern
174        (with a space rather than an '='). The man page documented the '=' forms,
175        which are compatible with GNU grep; these now work.
177    6.  No libpcreposix.pc file was created for pkg-config; there was just
178        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
180    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
181        when UCP support is not needed, by modifying the Python script that
182        generates it from Unicode data files. This should not matter if the module
183        is correctly used as a library, but I received one complaint about 50K of
184        unwanted data. My guess is that the person linked everything into his
185        program rather than using a library. Anyway, it does no harm.
187    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
188        was a minimum greater than 1 for a wide character in a possessive
189        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
190        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
191        character. Chaos in the form of incorrect output or a compiling loop could
192        result.
194    9.  The restrictions on what a pattern can contain when partial matching is
195        requested for pcre_exec() have been removed. All patterns can now be
196        partially matched by this function. In addition, if there are at least two
197        slots in the offset vector, the offset of the earliest inspected character
198        for the match and the offset of the end of the subject are set in them when
199        PCRE_ERROR_PARTIAL is returned.
201    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
202        synonymous with PCRE_PARTIAL, for backwards compatibility, and
203        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
204        and may be more useful for multi-segment matching.
206    11. Partial matching with pcre_exec() is now more intuitive. A partial match
207        used to be given if ever the end of the subject was reached; now it is
208        given only if matching could not proceed because another character was
209        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
210        string "Z", which now yields "no match" instead of "partial match". In the
211        case of pcre_dfa_exec(), "no match" is given if every matching path for the
212        final character ended with (*FAIL).
214    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
215        if the pattern had a "must contain" character that was already found in the
216        earlier partial match, unless partial matching was again requested. For
217        example, with the pattern /dog.(body)?/, the "must contain" character is
218        "g". If the first part-match was for the string "dog", restarting with
219        "sbody" failed. This bug has been fixed.
221    13. The string returned by pcre_dfa_exec() after a partial match has been
222        changed so that it starts at the first inspected character rather than the
223        first character of the match. This makes a difference only if the pattern
224        starts with a lookbehind assertion or \b or \B (\K is not supported by
225        pcre_dfa_exec()). It's an incompatible change, but it makes the two
226        matching functions compatible, and I think it's the right thing to do.
228    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
229        so that the demonstration program is easily available in environments where
230        PCRE has not been installed from source.
232    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
233        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
234        library.
236    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
237        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
238        is not the first non-POSIX option to be added. Clearly some people find
239        these options useful.
241    17. If a caller to the POSIX matching function regexec() passes a non-zero
242        value for nmatch with a NULL value for pmatch, the value of
243        nmatch is forced to zero.
245    18. RunGrepTest did not have a test for the availability of the -u option of
246        the diff command, as RunTest does. It now checks in the same way as
247        RunTest, and also checks for the -b option.
249    19. If an odd number of negated classes containing just a single character
250        interposed, within parentheses, between a forward reference to a named
251        subpattern and the definition of the subpattern, compilation crashed with
252        an internal error, complaining that it could not find the referenced
253        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
254        [The bug was that it was starting one character too far in when skipping
255        over the character class, thus treating the ] as data rather than
256        terminating the class. This meant it could skip too much.]
258    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
259        /g option in pcretest when the pattern contains \K, which makes it possible
260        to have an empty string match not at the start, even when the pattern is
261        anchored. Updated pcretest and pcredemo to use this option.
263    21. If the maximum number of capturing subpatterns in a recursion was greater
264        than the maximum at the outer level, the higher number was returned, but
265        with unset values at the outer level. The correct (outer level) value is
266        now given.
268    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
269        PCRE did not set those parentheses (unlike Perl). I have now found a way to
270        make it do so. The string so far is captured, making this feature
271        compatible with Perl.
273    23. The tests have been re-organized, adding tests 11 and 12, to make it
274        possible to check the Perl 5.10 features against Perl 5.10.
276    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
277        pattern matches a fixed length string. PCRE did not allow this; now it
278        does. Neither allows recursion.
280    25. I finally figured out how to implement a request to provide the minimum
281        length of subject string that was needed in order to match a given pattern.
282        (It was back references and recursion that I had previously got hung up
283        on.) This code has now been added to pcre_study(); it finds a lower bound
284        to the length of subject needed. It is not necessarily the greatest lower
285        bound, but using it to avoid searching strings that are too short does give
286        some useful speed-ups. The value is available to calling programs via
287        pcre_fullinfo().
289    26. While implementing 25, I discovered to my embarrassment that pcretest had
290        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
291        study optimizations had never been tested with that matching function.
292        Oops. What is worse, even when it was passed study data, there was a bug in
293        pcre_dfa_exec() that meant it never actually used it. Double oops. There
294        were also very few tests of studied patterns with pcre_dfa_exec().
296    27. If (?| is used to create subpatterns with duplicate numbers, they are now
297        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
298        on the other side of the coin, they are no longer allowed to have different
299        names, because these cannot be distinguished in PCRE, and this has caused
300        confusion. (This is a difference from Perl.)
302    28. When duplicate subpattern names are present (necessarily with different
303        numbers, as required by 27 above), and a test is made by name in a
304        conditional pattern, either for a subpattern having been matched, or for
305        recursion in such a pattern, all the associated numbered subpatterns are
306        tested, and the overall condition is true if the condition is true for any
307        one of them. This is the way Perl works, and is also more like the way
308        testing by number works.
311    Version 7.9 11-Apr-09
312  ---------------------  ---------------------
314  1.  When building with support for bzlib/zlib (pcregrep) and/or readline  1.  When building with support for bzlib/zlib (pcregrep) and/or readline
# Line 94  Version 7.9 xx-xxx-09 Line 401  Version 7.9 xx-xxx-09
401  23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name  23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
402      CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is      CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
403      included within another project.      included within another project.
405  24. Steven Van Ingelgem's patches to add more options to the CMake support,  24. Steven Van Ingelgem's patches to add more options to the CMake support,
406      slightly modified by me:      slightly modified by me:
408        (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including        (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
409            not building pcregrep.            not building pcregrep.
411        (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only        (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
412            if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.            if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
414  25. Forward references, both numeric and by name, in patterns that made use of  25. Forward references, both numeric and by name, in patterns that made use of
415      duplicate group numbers, could behave incorrectly or give incorrect errors,      duplicate group numbers, could behave incorrectly or give incorrect errors,
416      because when scanning forward to find the reference group, PCRE was not      because when scanning forward to find the reference group, PCRE was not
417      taking into account the duplicate group numbers. A pattern such as      taking into account the duplicate group numbers. A pattern such as
418      ^X(?3)(a)(?|(b)|(q))(Y) is an example.      ^X(?3)(a)(?|(b)|(q))(Y) is an example.
420  26. Changed a few more instances of "const unsigned char *" to USPTR, making  26. Changed a few more instances of "const unsigned char *" to USPTR, making
421      the feature of a custom pointer more persuasive (as requested by a user).      the feature of a custom pointer more persuasive (as requested by a user).
423    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
424        pcretest.c, inside #ifndefs, because it seems they are sometimes already
425        pre-defined.
427    28. Added support for (*UTF8) at the start of a pattern.
429    29. Arrange for flags added by the "release type" setting in CMake to be shown
430        in the configuration summary.
433  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

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