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revision 1417 by ph10, Tue Dec 24 18:03:06 2013 UTC revision 1534 by ph10, Tue Mar 24 10:33:21 2015 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.35-RC1 xx-xxxx-201x  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 and given the CVE number
85        CVE-2015-2325.
86    
87    23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
88        call within a group that also contained a recursive back reference caused
89        incorrect code to be compiled. This bug was reported as "heap overflow",
90        discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
91        number CVE-2015-2326.
92    
93    24. Computing the size of the JIT read-only data in advance has been a source
94        of various issues, and new ones are still appear unfortunately. To fix
95        existing and future issues, size computation is eliminated from the code,
96        and replaced by on-demand memory allocation.
97    
98    25. A pattern such as /(?i)[A-`]/, where characters in the other case are
99        adjacent to the end of the range, and the range contained characters with
100        more than one other case, caused incorrect behaviour when compiled in UTF
101        mode. In that example, the range a-j was left out of the class.
102    
103    26. Fix JIT compilation of conditional blocks, which assertion
104        is converted to (*FAIL). E.g: /(?(?!))/.
105    
106    27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
107        discovered by the LLVM fuzzer.
108    
109    28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
110        when this assertion was used as a condition, for example (?(?!)a|b). In
111        pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
112        error about an unsupported item.
113    
114    
115    Version 8.36 26-September-2014
116    ------------------------------
117    
118    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
119        -Wmissing-field-initializers and -Wunused-parameter.
120    
121    2.  The tests for quantifiers being too big (greater than 65535) were being
122        applied after reading the number, and stupidly assuming that integer
123        overflow would give a negative number. The tests are now applied as the
124        numbers are read.
125    
126    3.  Tidy code in pcre_exec.c where two branches that used to be different are
127        now the same.
128    
129    4.  The JIT compiler did not generate match limit checks for certain
130        bracketed expressions with quantifiers. This may lead to exponential
131        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
132        issue should be resolved now.
133    
134    5.  Fixed an issue, which occures when nested alternatives are optimized
135        with table jumps.
136    
137    6.  Inserted two casts and changed some ints to size_t in the light of some
138        reported 64-bit compiler warnings (Bugzilla 1477).
139    
140    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
141        an empty string, which sometimes were behaving incorrectly in the
142        interpreter (though correctly in the JIT matcher). This pcretest input is
143        an example:
144    
145          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
146          NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
147    
148        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
149        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
150        for an empty string was breaking the inner loop and carrying on at a lower
151        level, when possessive repeated groups should always return to a higher
152        level as they have no backtrack points in them. The empty string test now
153        occurs at the outer level.
154    
155    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
156        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
157    
158    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
159        doesn't).
160    
161    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
162        to hold a pattern to be incorrectly computed (too small) when there were
163        named back references to duplicated names. This could cause "internal
164        error: code overflow" or "double free or corruption" or other memory
165        handling errors.
166    
167    11. When named subpatterns had the same prefixes, back references could be
168        confused. For example, in this pattern:
169    
170          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
171    
172        the reference to 'Name' was incorrectly treated as a reference to a
173        duplicate name.
174    
175    12. A pattern such as /^s?c/mi8 where the optional character has more than
176        one "other case" was incorrectly compiled such that it would only try to
177        match starting at "c".
178    
179    13. When a pattern starting with \s was studied, VT was not included in the
180        list of possible starting characters; this should have been part of the
181        8.34/18 patch.
182    
183    14. If a character class started [\Qx]... where x is any character, the class
184        was incorrectly terminated at the ].
185    
186    15. If a pattern that started with a caseless match for a character with more
187        than one "other case" was studied, PCRE did not set up the starting code
188        unit bit map for the list of possible characters. Now it does. This is an
189        optimization improvement, not a bug fix.
190    
191    16. The Unicode data tables have been updated to Unicode 7.0.0.
192    
193    17. Fixed a number of memory leaks in pcregrep.
194    
195    18. Avoid a compiler warning (from some compilers) for a function call with
196        a cast that removes "const" from an lvalue by using an intermediate
197        variable (to which the compiler does not object).
198    
199    19. Incorrect code was compiled if a group that contained an internal recursive
200        back reference was optional (had quantifier with a minimum of zero). This
201        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
202        caused segmentation faults because of stack overflows at compile time.
203    
204    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
205        group that is quantified with an indefinite repeat, caused a compile-time
206        loop which used up all the system stack and provoked a segmentation fault.
207        This was not the same bug as 19 above.
208    
209    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
210        Patch by Mike Frysinger.
211    
212    
213    Version 8.35 04-April-2014
214    --------------------------
215    
216  1.  A new flag is set, when property checks are present in an XCLASS.  1.  A new flag is set, when property checks are present in an XCLASS.
217      When this flag is not set, PCRE can perform certain optimizations      When this flag is not set, PCRE can perform certain optimizations
# Line 11  Version 8.35-RC1 xx-xxxx-201x Line 220  Version 8.35-RC1 xx-xxxx-201x
220  2.  The auto-possessification of character sets were improved: a normal  2.  The auto-possessification of character sets were improved: a normal
221      and an extended character set can be compared now. Furthermore      and an extended character set can be compared now. Furthermore
222      the JIT compiler optimizes more character set checks.      the JIT compiler optimizes more character set checks.
223    
224  3.  Got rid of some compiler warnings for potentially uninitialized variables  3.  Got rid of some compiler warnings for potentially uninitialized variables
225      that show up only when compiled with -O2.      that show up only when compiled with -O2.
226    
227    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
228        of a match later then the end of the match. The pcretest program was not
229        handling the case sensibly - it was outputting from the start to the next
230        binary zero. It now reports this situation in a message, and outputs the
231        text from the end to the start.
232    
233    5.  Fast forward search is improved in JIT. Instead of the first three
234        characters, any three characters with fixed position can be searched.
235        Search order: first, last, middle.
236    
237    6.  Improve character range checks in JIT. Characters are read by an inprecise
238        function now, which returns with an unknown value if the character code is
239        above a certain threshold (e.g: 256). The only limitation is that the value
240        must be bigger than the threshold as well. This function is useful when
241        the characters above the threshold are handled in the same way.
242    
243    7.  The macros whose names start with RAWUCHAR are placeholders for a future
244        mode in which only the bottom 21 bits of 32-bit data items are used. To
245        make this more memorable for those maintaining the code, the names have
246        been changed to start with UCHAR21, and an extensive comment has been added
247        to their definition.
248    
249    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
250        to the export list in Makefile.am (they were accidentally omitted from the
251        8.34 tarball).
252    
253    9.  The informational output from pcretest used the phrase "starting byte set"
254        which is inappropriate for the 16-bit and 32-bit libraries. As the output
255        for "first char" and "need char" really means "non-UTF-char", I've changed
256        "byte" to "char", and slightly reworded the output. The documentation about
257        these values has also been (I hope) clarified.
258    
259    10. Another JIT related optimization: use table jumps for selecting the correct
260        backtracking path, when more than four alternatives are present inside a
261        bracket.
262    
263    11. Empty match is not possible, when the minimum length is greater than zero,
264        and there is no \K in the pattern. JIT should avoid empty match checks in
265        such cases.
266    
267    12. In a caseless character class with UCP support, when a character with more
268        than one alternative case was not the first character of a range, not all
269        the alternative cases were added to the class. For example, s and \x{17f}
270        are both alternative cases for S: the class [RST] was handled correctly,
271        but [R-T] was not.
272    
273    13. The configure.ac file always checked for pthread support when JIT was
274        enabled. This is not used in Windows, so I have put this test inside a
275        check for the presence of windows.h (which was already tested for).
276    
277    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
278        The algorithm provides a way to skip certain starting offsets, and usually
279        faster than linear prefix searches.
280    
281    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
282        as for 'fr_FR' and 'french'. For some reason, however, it then used the
283        Windows-specific input and output files, which have 'french' screwed in.
284        So this could never have worked. One of the problems with locales is that
285        they aren't always the same. I have now updated RunTest so that it checks
286        the output of the locale test (test 3) against three different output
287        files, and it allows the test to pass if any one of them matches. With luck
288        this should make the test pass on some versions of Solaris where it was
289        failing. Because of the uncertainty, the script did not used to stop if
290        test 3 failed; it now does. If further versions of a French locale ever
291        come to light, they can now easily be added.
292    
293    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
294        there was a message during ./configure, but it did not stop. This now
295        provokes an error. The invalid example in README has been corrected.
296        If a value less than the minimum is given, the minimum value has always
297        been used, but now a warning is given.
298    
299    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
300        was a bug in the test system, which is now fixed. Also, the list of various
301        configurations that are tested for each release did not have one with both
302        16/32 bits and --enable-bar-anycrlf. It now does.
303    
304    18. pcretest was missing "-C bsr" for displaying the \R default setting.
305    
306    19. Little endian PowerPC systems are supported now by the JIT compiler.
307    
308    20. The fast forward newline mechanism could enter to an infinite loop on
309        certain invalid UTF-8 input. Although we don't support these cases
310        this issue can be fixed by a performance optimization.
311    
312    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
313        not take account if existing stack usage. There is now a new global
314        variable called pcre_stack_guard that can be set to point to an external
315        function to check stack availability. It is called at the start of
316        processing every parenthesized group.
317    
318    22. A typo in the code meant that in ungreedy mode the max/min qualifier
319        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
320        not match "ab".
321    
322    23. When UTF was disabled, the JIT program reported some incorrect compile
323        errors. These messages are silenced now.
324    
325    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
326        compiler.
327    
328    25. Change all the temporary files used in RunGrepTest to be different to those
329        used by RunTest so that the tests can be run simultaneously, for example by
330        "make -j check".
331    
332    
333  Version 8.34 15-December-2013  Version 8.34 15-December-2013

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