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revision 462 by ph10, Sat Oct 17 19:55:02 2009 UTC revision 512 by ph10, Tue Mar 30 11:11:52 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.00 05-Oct-09  Version 8.03 26-Mar-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    
13    Version 8.02 19-Mar-2010
14    ------------------------
15    
16    1.  The Unicode data tables have been updated to Unicode 5.2.0.
17    
18    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
19        configured.
20    
21    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
22        original author of that file, following a query about its status.
23    
24    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
25        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
26    
27    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
28        quantifier applied to a forward-referencing subroutine call, could compile
29        incorrect code or give the error "internal error: previously-checked
30        referenced subpattern not found".
31    
32    6.  Both MS Visual Studio and Symbian OS have problems with initializing
33        variables to point to external functions. For these systems, therefore,
34        pcre_malloc etc. are now initialized to local functions that call the
35        relevant global functions.
36    
37    7.  There were two entries missing in the vectors called coptable and poptable
38        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
39        I've fixed the data, and added a kludgy way of testing at compile time that
40        the lengths are correct (equal to the number of opcodes).
41    
42    8.  Following on from 7, I added a similar kludge to check the length of the
43        eint vector in pcreposix.c.
44    
45    9.  Error texts for pcre_compile() are held as one long string to avoid too
46        much relocation at load time. To find a text, the string is searched,
47        counting zeros. There was no check for running off the end of the string,
48        which could happen if a new error number was added without updating the
49        string.
50    
51    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
52    
53    11. \K was not working if it appeared in an atomic group or in a group that
54        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
55        \K is "not well defined" if used in an assertion. PCRE now accepts it if
56        the assertion is positive, but not if it is negative.
57    
58    12. Change 11 fortuitously reduced the size of the stack frame used in the
59        "match()" function of pcre_exec.c by one pointer. Forthcoming
60        implementation of support for (*MARK) will need an extra pointer on the
61        stack; I have reserved it now, so that the stack frame size does not
62        decrease.
63    
64    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
65        item in branch that calls a recursion is a subroutine call - as in the
66        second branch in the above example - was incorrectly given the compile-
67        time error "recursive call could loop indefinitely" because pcre_compile()
68        was not correctly checking the subroutine for matching a non-empty string.
69    
70    14. The checks for overrunning compiling workspace could trigger after an
71        overrun had occurred. This is a "should never occur" error, but it can be
72        triggered by pathological patterns such as hundreds of nested parentheses.
73        The checks now trigger 100 bytes before the end of the workspace.
74    
75    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
76    
77    
78    Version 8.01 19-Jan-2010
79    ------------------------
80    
81    1.  If a pattern contained a conditional subpattern with only one branch (in
82        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
83        computed the wrong minimum data length (which is of course zero for such
84        subpatterns). This could cause incorrect "no match" results.
85    
86    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
87        the pattern is reset in the first branch, pcre_compile() failed with
88        "internal error: code overflow at offset...". This happened only when
89        the reset was to the original external option setting. (An optimization
90        abstracts leading options settings into an external setting, which was the
91        cause of this.)
92    
93    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
94        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
95        assertion pattern did not match (meaning that the assertion was true), it
96        was incorrectly treated as false if the SKIP had been reached during the
97        matching. This also applied to assertions used as conditions.
98    
99    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
100        assertion subpattern, including such a pattern used as a condition,
101        unpredictable results occurred, instead of the error return
102        PCRE_ERROR_DFA_UITEM.
103    
104    5.  The C++ GlobalReplace function was not working like Perl for the special
105        situation when an empty string is matched. It now does the fancy magic
106        stuff that is necessary.
107    
108    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
109        removed. (These were left over from very, very early versions of PCRE.)
110    
111    7.  Some cosmetic changes to the code to make life easier when compiling it
112        as part of something else:
113    
114        (a) Change DEBUG to PCRE_DEBUG.
115    
116        (b) In pcre_compile(), rename the member of the "branch_chain" structure
117            called "current" as "current_branch", to prevent a collision with the
118            Linux macro when compiled as a kernel module.
119    
120        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
121            prevent a collision with the Linux macro when compiled as a kernel
122            module.
123    
124    8.  In pcre_compile() there are some checks for integer overflows that used to
125        cast potentially large values to (double). This has been changed to that
126        when building, a check for int64_t is made, and if it is found, it is used
127        instead, thus avoiding the use of floating point arithmetic. (There is no
128        other use of FP in PCRE.) If int64_t is not found, the fallback is to
129        double.
130    
131    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
132        2005 (difference between two addresses compared to an unsigned value).
133    
134    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
135        custom one, because of the following reported problem in Windows:
136    
137          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
138              under Win32.
139          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
140              therefore missing the function definition.
141          - The compiler thus generates a "C" signature for the test function.
142          - The linker fails to find the "C" function.
143          - PCRE fails to configure if asked to do so against libbz2.
144    
145    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
146        messages were output:
147    
148          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
149          rerunning libtoolize, to keep the correct libtool macros in-tree.
150          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
151    
152        I have done both of these things.
153    
154    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
155        most of the time, it *can* run out if it is given a pattern that contains a
156        runaway infinite recursion. I updated the discussion in the pcrestack man
157        page.
158    
159    13. Now that we have gone to the x.xx style of version numbers, the minor
160        version may start with zero. Using 08 or 09 is a bad idea because users
161        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
162        interpreted as invalid octal numbers. I've updated the previous comment in
163        configure.ac, and also added a check that gives an error if 08 or 09 are
164        used.
165    
166    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
167        causing partial matching to fail when the end of the subject matched \W
168        in a UTF-8 pattern where \W was quantified with a minimum of 3.
169    
170    15. There were some discrepancies between the declarations in pcre_internal.h
171        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
172        their definitions. The declarations used "const uschar *" and the
173        definitions used USPTR. Even though USPTR is normally defined as "const
174        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
175        reported that: "This difference in casting confuses some C++ compilers, for
176        example, SunCC recognizes above declarations as different functions and
177        generates broken code for hbpcre." I have changed the declarations to use
178        USPTR.
179    
180    16. GNU libtool is named differently on some systems. The autogen.sh script now
181        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
182        (FreeBSD).
183    
184    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
185        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
186        comment: "Figure out how to create a longlong from a string: strtoll and
187        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
188        instance, but it only takes 2 args instead of 3!"
189    
190    18. A subtle bug concerned with back references has been fixed by a change of
191        specification, with a corresponding code fix. A pattern such as
192        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
193        refers, was giving matches when it shouldn't. For example, xa=xaaa would
194        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
195        same bug. Such groups have to be quantified to be useful, or contained
196        inside another quantified group. (If there's no repetition, the reference
197        can never match.) The problem arises because, having left the group and
198        moved on to the rest of the pattern, a later failure that backtracks into
199        the group uses the captured value from the final iteration of the group
200        rather than the correct earlier one. I have fixed this in PCRE by forcing
201        any group that contains a reference to itself to be an atomic group; that
202        is, there cannot be any backtracking into it once it has completed. This is
203        similar to recursive and subroutine calls.
204    
205    
206    Version 8.00 19-Oct-09
207  ----------------------  ----------------------
208    
209  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

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