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

Diff of /code/trunk/ChangeLog

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

revision 1477 by ph10, Wed May 21 17:53:49 2014 UTC revision 1530 by zherczeg, Thu Mar 5 08:53:37 2015 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.36 xx-xxx-2014  Version 8.37 xx-xxx-2015
5  ------------------------  ------------------------
6    
7    1.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
8        for those parentheses to be closed with whatever has been captured so far.
9        However, it was failing to mark any other groups between the hightest
10        capture so far and the currrent group as "unset". Thus, the ovector for
11        those groups contained whatever was previously there. An example is the
12        pattern /(x)|((*ACCEPT))/ when matched against "abcd".
13    
14    2.  If an assertion condition was quantified with a minimum of zero (an odd
15        thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
16    
17    3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
18        unrecognized modifier, a crash could occur.
19    
20    4.  An attempt to do global matching in pcretest with a zero-length ovector
21        caused a crash.
22    
23    5.  Fixed a memory leak during matching that could occur for a subpattern
24        subroutine call (recursive or otherwise) if the number of captured groups
25        that had to be saved was greater than ten.
26    
27    6.  Catch a bad opcode during auto-possessification after compiling a bad UTF
28        string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
29        UTF with NO_UTF_CHECK is documented as having an undefined outcome.
30    
31    7.  A UTF pattern containing a "not" match of a non-ASCII character and a
32        subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
33    
34    8. When a pattern is compiled, it remembers the highest back reference so that
35       when matching, if the ovector is too small, extra memory can be obtained to
36       use instead. A conditional subpattern whose condition is a check on a
37       capture having happened, such as, for example in the pattern
38       /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
39       setting the highest backreference number. This mattered only if pcre_exec()
40       was called with an ovector that was too small to hold the capture, and there
41       was no other kind of back reference (a situation which is probably quite
42       rare). The effect of the bug was that the condition was always treated as
43       FALSE when the capture could not be consulted, leading to a incorrect
44       behaviour by pcre2_match(). This bug has been fixed.
45    
46    9. A reference to a duplicated named group (either a back reference or a test
47       for being set in a conditional) that occurred in a part of the pattern where
48       PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
49       to be incorrectly calculated, leading to overwriting.
50    
51    10. A mutually recursive set of back references such as (\2)(\1) caused a
52        segfault at study time (while trying to find the minimum matching length).
53        The infinite loop is now broken (with the minimum length unset, that is,
54        zero).
55    
56    11. If an assertion that was used as a condition was quantified with a minimum
57        of zero, matching went wrong. In particular, if the whole group had
58        unlimited repetition and could match an empty string, a segfault was
59        likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
60        assertions to be quantified, but not if they are being used as conditions,
61        so the above pattern is faulted by Perl. PCRE has now been changed so that
62        it also rejects such patterns.
63    
64    12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
65        failed to allow the zero-repeat case if pcre2_exec() was called with an
66        ovector too small to capture the group.
67    
68    13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
69        Red Hat Product Security:
70    
71        (a) A crash if /K and /F were both set with the option to save the compiled
72        pattern.
73    
74        (b) Another crash if the option to print captured substrings in a callout
75        was combined with setting a null ovector, for example \O\C+ as a subject
76        string.
77    
78    14. A pattern such as "((?2){0,1999}())?", which has a group containing a
79        forward reference repeated a large (but limited) number of times within a
80        repeated outer group that has a zero minimum quantifier, caused incorrect
81        code to be compiled, leading to the error "internal error:
82        previously-checked referenced subpattern not found" when an incorrect
83        memory address was read. This bug was reported as "heap overflow",
84        discovered by Kai Lu of Fortinet's FortiGuard Labs.
85    
86    23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
87        call within a group that also contained a recursive back reference caused
88        incorrect code to be compiled. This bug was reported as "heap overflow",
89        discovered by Kai Lu of Fortinet's FortiGuard Labs.
90    
91    24. Computing the size of the JIT read-only data in advance has been a source
92        of various issues, and new ones are still appear unfortunately. To fix
93        existing and future issues, size computation is eliminated from the code,
94        and replaced by on-demand memory allocation.
95    
96    
97    Version 8.36 26-September-2014
98    ------------------------------
99    
100  1.  Got rid of some compiler warnings in the C++ modules that were shown up by  1.  Got rid of some compiler warnings in the C++ modules that were shown up by
101      -Wmissing-field-initializers and -Wunused-parameter.      -Wmissing-field-initializers and -Wunused-parameter.
102    
103  2.  The tests for quantifiers being too big (greater than 65535) were being  2.  The tests for quantifiers being too big (greater than 65535) were being
104      applied after reading the number, and stupidly assuming that integer      applied after reading the number, and stupidly assuming that integer
105      overflow would give a negative number. The tests are now applied as the      overflow would give a negative number. The tests are now applied as the
106      numbers are read.      numbers are read.
107    
108  3.  Tidy code in pcre_exec.c where two branches that used to be different are  3.  Tidy code in pcre_exec.c where two branches that used to be different are
109      now the same.      now the same.
110    
111  4.  The JIT compiler did not generate match limit checks for certain  4.  The JIT compiler did not generate match limit checks for certain
112      bracketed expressions with quantifiers. This may lead to exponential      bracketed expressions with quantifiers. This may lead to exponential
# Line 22  Version 8.36 xx-xxx-2014 Line 115  Version 8.36 xx-xxx-2014
115    
116  5.  Fixed an issue, which occures when nested alternatives are optimized  5.  Fixed an issue, which occures when nested alternatives are optimized
117      with table jumps.      with table jumps.
118    
119  6.  Inserted two casts and changed some ints to size_t in the light of some  6.  Inserted two casts and changed some ints to size_t in the light of some
120      reported 64-bit compiler warnings (Bugzilla 1477).      reported 64-bit compiler warnings (Bugzilla 1477).
121    
122    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
123        an empty string, which sometimes were behaving incorrectly in the
124        interpreter (though correctly in the JIT matcher). This pcretest input is
125        an example:
126    
127          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
128          NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
129    
130        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
131        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
132        for an empty string was breaking the inner loop and carrying on at a lower
133        level, when possessive repeated groups should always return to a higher
134        level as they have no backtrack points in them. The empty string test now
135        occurs at the outer level.
136    
137    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
138        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
139    
140    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
141        doesn't).
142    
143    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
144        to hold a pattern to be incorrectly computed (too small) when there were
145        named back references to duplicated names. This could cause "internal
146        error: code overflow" or "double free or corruption" or other memory
147        handling errors.
148    
149    11. When named subpatterns had the same prefixes, back references could be
150        confused. For example, in this pattern:
151    
152          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
153    
154        the reference to 'Name' was incorrectly treated as a reference to a
155        duplicate name.
156    
157    12. A pattern such as /^s?c/mi8 where the optional character has more than
158        one "other case" was incorrectly compiled such that it would only try to
159        match starting at "c".
160    
161    13. When a pattern starting with \s was studied, VT was not included in the
162        list of possible starting characters; this should have been part of the
163        8.34/18 patch.
164    
165    14. If a character class started [\Qx]... where x is any character, the class
166        was incorrectly terminated at the ].
167    
168    15. If a pattern that started with a caseless match for a character with more
169        than one "other case" was studied, PCRE did not set up the starting code
170        unit bit map for the list of possible characters. Now it does. This is an
171        optimization improvement, not a bug fix.
172    
173    16. The Unicode data tables have been updated to Unicode 7.0.0.
174    
175    17. Fixed a number of memory leaks in pcregrep.
176    
177    18. Avoid a compiler warning (from some compilers) for a function call with
178        a cast that removes "const" from an lvalue by using an intermediate
179        variable (to which the compiler does not object).
180    
181    19. Incorrect code was compiled if a group that contained an internal recursive
182        back reference was optional (had quantifier with a minimum of zero). This
183        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
184        caused segmentation faults because of stack overflows at compile time.
185    
186    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
187        group that is quantified with an indefinite repeat, caused a compile-time
188        loop which used up all the system stack and provoked a segmentation fault.
189        This was not the same bug as 19 above.
190    
191    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
192        Patch by Mike Frysinger.
193    
194    
195  Version 8.35 04-April-2014  Version 8.35 04-April-2014
# Line 53  Version 8.35 04-April-2014 Line 218  Version 8.35 04-April-2014
218    
219  6.  Improve character range checks in JIT. Characters are read by an inprecise  6.  Improve character range checks in JIT. Characters are read by an inprecise
220      function now, which returns with an unknown value if the character code is      function now, which returns with an unknown value if the character code is
221      above a certain treshold (e.g: 256). The only limitation is that the value      above a certain threshold (e.g: 256). The only limitation is that the value
222      must be bigger than the treshold as well. This function is useful, when      must be bigger than the threshold as well. This function is useful when
223      the characters above the treshold are handled in the same way.      the characters above the threshold are handled in the same way.
224    
225  7.  The macros whose names start with RAWUCHAR are placeholders for a future  7.  The macros whose names start with RAWUCHAR are placeholders for a future
226      mode in which only the bottom 21 bits of 32-bit data items are used. To      mode in which only the bottom 21 bits of 32-bit data items are used. To

Legend:
Removed from v.1477  
changed lines
  Added in v.1530

  ViewVC Help
Powered by ViewVC 1.1.5