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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.00 ??-???-??  Version 8.02 01-Mar-2010
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 5.2.0.
8    
9    
10    Version 8.01 19-Jan-2010
11    ------------------------
12    
13    1.  If a pattern contained a conditional subpattern with only one branch (in
14        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
15        computed the wrong minimum data length (which is of course zero for such
16        subpatterns). This could cause incorrect "no match" results.
17    
18    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
19        the pattern is reset in the first branch, pcre_compile() failed with
20        "internal error: code overflow at offset...". This happened only when
21        the reset was to the original external option setting. (An optimization
22        abstracts leading options settings into an external setting, which was the
23        cause of this.)
24    
25    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
26        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
27        assertion pattern did not match (meaning that the assertion was true), it
28        was incorrectly treated as false if the SKIP had been reached during the
29        matching. This also applied to assertions used as conditions.
30    
31    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
32        assertion subpattern, including such a pattern used as a condition,
33        unpredictable results occurred, instead of the error return
34        PCRE_ERROR_DFA_UITEM.
35    
36    5.  The C++ GlobalReplace function was not working like Perl for the special
37        situation when an empty string is matched. It now does the fancy magic
38        stuff that is necessary.
39    
40    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
41        removed. (These were left over from very, very early versions of PCRE.)
42    
43    7.  Some cosmetic changes to the code to make life easier when compiling it
44        as part of something else:
45    
46        (a) Change DEBUG to PCRE_DEBUG.
47    
48        (b) In pcre_compile(), rename the member of the "branch_chain" structure
49            called "current" as "current_branch", to prevent a collision with the
50            Linux macro when compiled as a kernel module.
51    
52        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
53            prevent a collision with the Linux macro when compiled as a kernel
54            module.
55    
56    8.  In pcre_compile() there are some checks for integer overflows that used to
57        cast potentially large values to (double). This has been changed to that
58        when building, a check for int64_t is made, and if it is found, it is used
59        instead, thus avoiding the use of floating point arithmetic. (There is no
60        other use of FP in PCRE.) If int64_t is not found, the fallback is to
61        double.
62    
63    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
64        2005 (difference between two addresses compared to an unsigned value).
65    
66    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
67        custom one, because of the following reported problem in Windows:
68    
69          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
70              under Win32.
71          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
72              therefore missing the function definition.
73          - The compiler thus generates a "C" signature for the test function.
74          - The linker fails to find the "C" function.
75          - PCRE fails to configure if asked to do so against libbz2.
76    
77    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
78        messages were output:
79    
80          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
81          rerunning libtoolize, to keep the correct libtool macros in-tree.
82          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
83    
84        I have done both of these things.
85    
86    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
87        most of the time, it *can* run out if it is given a pattern that contains a
88        runaway infinite recursion. I updated the discussion in the pcrestack man
89        page.
90    
91    13. Now that we have gone to the x.xx style of version numbers, the minor
92        version may start with zero. Using 08 or 09 is a bad idea because users
93        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
94        interpreted as invalid octal numbers. I've updated the previous comment in
95        configure.ac, and also added a check that gives an error if 08 or 09 are
96        used.
97    
98    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
99        causing partial matching to fail when the end of the subject matched \W
100        in a UTF-8 pattern where \W was quantified with a minimum of 3.
101    
102    15. There were some discrepancies between the declarations in pcre_internal.h
103        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
104        their definitions. The declarations used "const uschar *" and the
105        definitions used USPTR. Even though USPTR is normally defined as "const
106        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
107        reported that: "This difference in casting confuses some C++ compilers, for
108        example, SunCC recognizes above declarations as different functions and
109        generates broken code for hbpcre." I have changed the declarations to use
110        USPTR.
111    
112    16. GNU libtool is named differently on some systems. The autogen.sh script now
113        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
114        (FreeBSD).
115    
116    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
117        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
118        comment: "Figure out how to create a longlong from a string: strtoll and
119        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
120        instance, but it only takes 2 args instead of 3!"
121    
122    18. A subtle bug concerned with back references has been fixed by a change of
123        specification, with a corresponding code fix. A pattern such as
124        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
125        refers, was giving matches when it shouldn't. For example, xa=xaaa would
126        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
127        same bug. Such groups have to be quantified to be useful, or contained
128        inside another quantified group. (If there's no repetition, the reference
129        can never match.) The problem arises because, having left the group and
130        moved on to the rest of the pattern, a later failure that backtracks into
131        the group uses the captured value from the final iteration of the group
132        rather than the correct earlier one. I have fixed this in PCRE by forcing
133        any group that contains a reference to itself to be an atomic group; that
134        is, there cannot be any backtracking into it once it has completed. This is
135        similar to recursive and subroutine calls.
136    
137    
138    Version 8.00 19-Oct-09
139  ----------------------  ----------------------
140    
141  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
142      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
143      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
144      error.      error.
145    
146  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,
147      "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
148      in a Windows environment.      in a Windows environment.
149    
150  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
151      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
152      --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
153      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
154      prints the file name in this circumstance, but including the count seems      prints the file name in this circumstance, but including the count seems
155      more useful - otherwise, why use --count?) Also ensured that the      more useful - otherwise, why use --count?) Also ensured that the
156      combination -clh just lists non-zero counts, with no names.      combination -clh just lists non-zero counts, with no names.
157    
158  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
159      --fixed_strings instead of --fixed-strings. This is an incompatible change,      --fixed_strings instead of --fixed-strings. This is an incompatible change,
160      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
161      the old behaviour.      the old behaviour.
162    
163  5.  The command line items --regex=pattern and --regexp=pattern were not  5.  The command line items --regex=pattern and --regexp=pattern were not
164      recognized by pcregrep, which required --regex pattern or --regexp pattern      recognized by pcregrep, which required --regex pattern or --regexp pattern
165      (with a space rather than an '='). The man page documented the '=' forms,      (with a space rather than an '='). The man page documented the '=' forms,
166      which are compatible with GNU grep; these now work.      which are compatible with GNU grep; these now work.
167    
168  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
169      libpcre.pc and libpcrecpp.pc. The omission has been rectified.      libpcre.pc and libpcrecpp.pc. The omission has been rectified.
170    
171  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
172      when UCP support is not needed, by modifying the Python script that      when UCP support is not needed, by modifying the Python script that
173      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
174      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
175      unwanted data. My guess is that the person linked everything into his      unwanted data. My guess is that the person linked everything into his
176      program rather than using a library. Anyway, it does no harm.      program rather than using a library. Anyway, it does no harm.
177    
178  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
179      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
180      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
181      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
182      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
183      result.      result.
184    
185  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
186      requested for pcre_exec() have been removed. All patterns can now be      requested for pcre_exec() have been removed. All patterns can now be
187      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
188      slots in the offset vector, the offset of the earliest inspected character      slots in the offset vector, the offset of the earliest inspected character
189      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
190      PCRE_ERROR_PARTIAL is returned.      PCRE_ERROR_PARTIAL is returned.
191    
192  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
193      synonymous with PCRE_PARTIAL, for backwards compatibility, and      synonymous with PCRE_PARTIAL, for backwards compatibility, and
194      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,
195      and may be more useful for multi-segment matching, especially with      and may be more useful for multi-segment matching.
196      pcre_exec().  
197    11. Partial matching with pcre_exec() is now more intuitive. A partial match
198  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
199      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
200      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
201      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
202      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
203      case of pcre_dfa_exec(), "no match" is given if every matching path for the      final character ended with (*FAIL).
204      final character ended with (*FAIL).  
   
205  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
206      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
207      earlier partial match, unless partial matching was again requested. For      earlier partial match, unless partial matching was again requested. For
208      example, with the pattern /dog.(body)?/, the "must contain" character is      example, with the pattern /dog.(body)?/, the "must contain" character is
209      "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
210      "sbody" failed. This bug has been fixed.      "sbody" failed. This bug has been fixed.
211    
212  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
213      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
214      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
215      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
216      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
217      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.
218    
219  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,
220      so that the demonstration program is easily available in environments where      so that the demonstration program is easily available in environments where
221      PCRE has not been installed from source.      PCRE has not been installed from source.
222    
223  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,
224      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
225      library.      library.
226    
227  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.
228      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
229      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
230      these options useful.      these options useful.
231    
232  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
233      value for nmatch with a NULL value for pmatch, the value of      value for nmatch with a NULL value for pmatch, the value of
234      nmatch is forced to zero.      nmatch is forced to zero.
235    
236  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
237      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
238      RunTest, and also checks for the -b option.      RunTest, and also checks for the -b option.
239    
240  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
241      interposed, within parentheses, between a forward reference to a named      interposed, within parentheses, between a forward reference to a named
242      subpattern and the definition of the subpattern, compilation crashed with      subpattern and the definition of the subpattern, compilation crashed with
243      an internal error, complaining that it could not find the referenced      an internal error, complaining that it could not find the referenced
244      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
245      [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
246      over the character class, thus treating the ] as data rather than      over the character class, thus treating the ] as data rather than
247      terminating the class. This meant it could skip too much.]      terminating the class. This meant it could skip too much.]
248    
249  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
250      /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
251      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
252      anchored. Updated pcretest and pcredemo to use this option.      anchored. Updated pcretest and pcredemo to use this option.
253    
254  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
255      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
256      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
257      now given.      now given.
258    
259  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of  22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
260      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
261      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
262      compatible with Perl.      compatible with Perl.
263    
264  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
265      possible to check the Perl 5.10 features against Perl 5.10.      possible to check the Perl 5.10 features against Perl 5.10.
266    
267  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
268      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
269      does. Neither allows recursion.      does. Neither allows recursion.
270    
271  25. I finally figured out how to implement a request to provide the minimum  25. I finally figured out how to implement a request to provide the minimum
272      length of subject string that was needed in order to match a given pattern.      length of subject string that was needed in order to match a given pattern.
273      (It was back references and recursion that I had previously got hung up      (It was back references and recursion that I had previously got hung up
274      on.) This code has now been added to pcre_study(); it finds a lower bound      on.) This code has now been added to pcre_study(); it finds a lower bound
275      to the length of subject needed. It is not necessarily the greatest lower      to the length of subject needed. It is not necessarily the greatest lower
276      bound, but using it to avoid searching strings that are too short does give      bound, but using it to avoid searching strings that are too short does give
277      some useful speed-ups. The value is available to calling programs via      some useful speed-ups. The value is available to calling programs via
278      pcre_fullinfo().      pcre_fullinfo().
279    
280  26. While implementing 25, I discovered to my embarrassment that pcretest had  26. While implementing 25, I discovered to my embarrassment that pcretest had
281      not been passing the result of pcre_study() to pcre_dfa_exec(), so the      not been passing the result of pcre_study() to pcre_dfa_exec(), so the
282      study optimizations had never been tested with that matching function.      study optimizations had never been tested with that matching function.
283      Oops. What is worse, even when it was passed study data, there was a bug in      Oops. What is worse, even when it was passed study data, there was a bug in
284      pcre_dfa_exec() that meant it never actually used it. Double oops. There      pcre_dfa_exec() that meant it never actually used it. Double oops. There
285      were also very few tests of studied patterns with pcre_dfa_exec().      were also very few tests of studied patterns with pcre_dfa_exec().
286    
287    27. If (?| is used to create subpatterns with duplicate numbers, they are now
288        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
289        on the other side of the coin, they are no longer allowed to have different
290        names, because these cannot be distinguished in PCRE, and this has caused
291        confusion. (This is a difference from Perl.)
292    
293    28. When duplicate subpattern names are present (necessarily with different
294        numbers, as required by 27 above), and a test is made by name in a
295        conditional pattern, either for a subpattern having been matched, or for
296        recursion in such a pattern, all the associated numbered subpatterns are
297        tested, and the overall condition is true if the condition is true for any
298        one of them. This is the way Perl works, and is also more like the way
299        testing by number works.
300    
301    
302  Version 7.9 11-Apr-09  Version 7.9 11-Apr-09
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