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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    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10        configured.
11    
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.
14    
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.
17    
18    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19        quantifier applied to a forward-referencing subroutine call, could compile
20        incorrect code or give the error "internal error: previously-checked
21        referenced subpattern not found".
22    
23    6.  Both MS Visual Studio and Symbian OS have problems with initializing
24        variables to point to external functions. For these systems, therefore,
25        pcre_malloc etc. are now initialized to local functions that call the
26        relevant global functions.
27    
28    7.  There were two entries missing in the vectors called coptable and poptable
29        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
30        I've fixed the data, and added a kludgy way of testing at compile time that
31        the lengths are correct (equal to the number of opcodes).
32    
33    8.  Following on from 7, I added a similar kludge to check the length of the
34        eint vector in pcreposix.c.
35    
36    9.  Error texts for pcre_compile() are held as one long string to avoid too
37        much relocation at load time. To find a text, the string is searched,
38        counting zeros. There was no check for running off the end of the string,
39        which could happen if a new error number was added without updating the
40        string.
41    
42    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
43    
44    11. \K was not working if it appeared in an atomic group or in a group that
45        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
46        \K is "not well defined" if used in an assertion. PCRE now accepts it if
47        the assertion is positive, but not if it is negative.
48    
49    12. Change 11 fortuitously reduced the size of the stack frame used in the
50        "match()" function of pcre_exec.c by one pointer. Forthcoming
51        implementation of support for (*MARK) will need an extra pointer on the
52        stack; I have reserved it now, so that the stack frame size does not
53        decrease.
54    
55    
56    Version 8.01 19-Jan-2010
57    ------------------------
58    
59    1.  If a pattern contained a conditional subpattern with only one branch (in
60        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
61        computed the wrong minimum data length (which is of course zero for such
62        subpatterns). This could cause incorrect "no match" results.
63    
64    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
65        the pattern is reset in the first branch, pcre_compile() failed with
66        "internal error: code overflow at offset...". This happened only when
67        the reset was to the original external option setting. (An optimization
68        abstracts leading options settings into an external setting, which was the
69        cause of this.)
70    
71    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
72        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
73        assertion pattern did not match (meaning that the assertion was true), it
74        was incorrectly treated as false if the SKIP had been reached during the
75        matching. This also applied to assertions used as conditions.
76    
77    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
78        assertion subpattern, including such a pattern used as a condition,
79        unpredictable results occurred, instead of the error return
80        PCRE_ERROR_DFA_UITEM.
81    
82    5.  The C++ GlobalReplace function was not working like Perl for the special
83        situation when an empty string is matched. It now does the fancy magic
84        stuff that is necessary.
85    
86    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
87        removed. (These were left over from very, very early versions of PCRE.)
88    
89    7.  Some cosmetic changes to the code to make life easier when compiling it
90        as part of something else:
91    
92        (a) Change DEBUG to PCRE_DEBUG.
93    
94        (b) In pcre_compile(), rename the member of the "branch_chain" structure
95            called "current" as "current_branch", to prevent a collision with the
96            Linux macro when compiled as a kernel module.
97    
98        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
99            prevent a collision with the Linux macro when compiled as a kernel
100            module.
101    
102    8.  In pcre_compile() there are some checks for integer overflows that used to
103        cast potentially large values to (double). This has been changed to that
104        when building, a check for int64_t is made, and if it is found, it is used
105        instead, thus avoiding the use of floating point arithmetic. (There is no
106        other use of FP in PCRE.) If int64_t is not found, the fallback is to
107        double.
108    
109    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
110        2005 (difference between two addresses compared to an unsigned value).
111    
112    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
113        custom one, because of the following reported problem in Windows:
114    
115          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
116              under Win32.
117          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
118              therefore missing the function definition.
119          - The compiler thus generates a "C" signature for the test function.
120          - The linker fails to find the "C" function.
121          - PCRE fails to configure if asked to do so against libbz2.
122    
123    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
124        messages were output:
125    
126          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
127          rerunning libtoolize, to keep the correct libtool macros in-tree.
128          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
129    
130        I have done both of these things.
131    
132    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
133        most of the time, it *can* run out if it is given a pattern that contains a
134        runaway infinite recursion. I updated the discussion in the pcrestack man
135        page.
136    
137    13. Now that we have gone to the x.xx style of version numbers, the minor
138        version may start with zero. Using 08 or 09 is a bad idea because users
139        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
140        interpreted as invalid octal numbers. I've updated the previous comment in
141        configure.ac, and also added a check that gives an error if 08 or 09 are
142        used.
143    
144    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
145        causing partial matching to fail when the end of the subject matched \W
146        in a UTF-8 pattern where \W was quantified with a minimum of 3.
147    
148    15. There were some discrepancies between the declarations in pcre_internal.h
149        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
150        their definitions. The declarations used "const uschar *" and the
151        definitions used USPTR. Even though USPTR is normally defined as "const
152        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
153        reported that: "This difference in casting confuses some C++ compilers, for
154        example, SunCC recognizes above declarations as different functions and
155        generates broken code for hbpcre." I have changed the declarations to use
156        USPTR.
157    
158    16. GNU libtool is named differently on some systems. The autogen.sh script now
159        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
160        (FreeBSD).
161    
162    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
163        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
164        comment: "Figure out how to create a longlong from a string: strtoll and
165        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
166        instance, but it only takes 2 args instead of 3!"
167    
168    18. A subtle bug concerned with back references has been fixed by a change of
169        specification, with a corresponding code fix. A pattern such as
170        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
171        refers, was giving matches when it shouldn't. For example, xa=xaaa would
172        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
173        same bug. Such groups have to be quantified to be useful, or contained
174        inside another quantified group. (If there's no repetition, the reference
175        can never match.) The problem arises because, having left the group and
176        moved on to the rest of the pattern, a later failure that backtracks into
177        the group uses the captured value from the final iteration of the group
178        rather than the correct earlier one. I have fixed this in PCRE by forcing
179        any group that contains a reference to itself to be an atomic group; that
180        is, there cannot be any backtracking into it once it has completed. This is
181        similar to recursive and subroutine calls.
182    
183    
184    Version 8.00 19-Oct-09
185  ----------------------  ----------------------
186    
187  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
188      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
189      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
190      error.      error.
191    
192  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,
193      "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
194      in a Windows environment.      in a Windows environment.
195    
196  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
197      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
198      --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
199      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
200      prints the file name in this circumstance, but including the count seems      prints the file name in this circumstance, but including the count seems
201      more useful - otherwise, why use --count?) Also ensured that the      more useful - otherwise, why use --count?) Also ensured that the
202      combination -clh just lists non-zero counts, with no names.      combination -clh just lists non-zero counts, with no names.
203    
204  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
205      --fixed_strings instead of --fixed-strings. This is an incompatible change,      --fixed_strings instead of --fixed-strings. This is an incompatible change,
206      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
207      the old behaviour.      the old behaviour.
208    
209  5.  The command line items --regex=pattern and --regexp=pattern were not  5.  The command line items --regex=pattern and --regexp=pattern were not
210      recognized by pcregrep, which required --regex pattern or --regexp pattern      recognized by pcregrep, which required --regex pattern or --regexp pattern
211      (with a space rather than an '='). The man page documented the '=' forms,      (with a space rather than an '='). The man page documented the '=' forms,
212      which are compatible with GNU grep; these now work.      which are compatible with GNU grep; these now work.
213    
214  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
215      libpcre.pc and libpcrecpp.pc. The omission has been rectified.      libpcre.pc and libpcrecpp.pc. The omission has been rectified.
216    
217  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
218      when UCP support is not needed, by modifying the Python script that      when UCP support is not needed, by modifying the Python script that
219      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
220      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
221      unwanted data. My guess is that the person linked everything into his      unwanted data. My guess is that the person linked everything into his
222      program rather than using a library. Anyway, it does no harm.      program rather than using a library. Anyway, it does no harm.
223    
224  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
225      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
226      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
227      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
228      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
229      result.      result.
230    
231  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
232      requested for pcre_exec() have been removed. All patterns can now be      requested for pcre_exec() have been removed. All patterns can now be
233      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
234      slots in the offset vector, the offset of the earliest inspected character      slots in the offset vector, the offset of the earliest inspected character
235      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
236      PCRE_ERROR_PARTIAL is returned.      PCRE_ERROR_PARTIAL is returned.
237    
238  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
239      synonymous with PCRE_PARTIAL, for backwards compatibility, and      synonymous with PCRE_PARTIAL, for backwards compatibility, and
240      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,
241      and may be more useful for multi-segment matching, especially with      and may be more useful for multi-segment matching.
242      pcre_exec().  
243    11. Partial matching with pcre_exec() is now more intuitive. A partial match
244  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
245      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
246      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
247      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
248      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
249      case of pcre_dfa_exec(), "no match" is given if every matching path for the      final character ended with (*FAIL).
250      final character ended with (*FAIL).  
   
251  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
252      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
253      earlier partial match, unless partial matching was again requested. For      earlier partial match, unless partial matching was again requested. For
254      example, with the pattern /dog.(body)?/, the "must contain" character is      example, with the pattern /dog.(body)?/, the "must contain" character is
255      "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
256      "sbody" failed. This bug has been fixed.      "sbody" failed. This bug has been fixed.
257    
258  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
259      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
260      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
261      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
262      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
263      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.
264    
265  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,
266      so that the demonstration program is easily available in environments where      so that the demonstration program is easily available in environments where
267      PCRE has not been installed from source.      PCRE has not been installed from source.
268    
269  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,
270      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
271      library.      library.
272    
273  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.
274      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
275      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
276      these options useful.      these options useful.
277    
278  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
279      value for nmatch with a NULL value for pmatch, the value of      value for nmatch with a NULL value for pmatch, the value of
280      nmatch is forced to zero.      nmatch is forced to zero.
281    
282  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
283      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
284      RunTest, and also checks for the -b option.      RunTest, and also checks for the -b option.
285    
286  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
287      interposed, within parentheses, between a forward reference to a named      interposed, within parentheses, between a forward reference to a named
288      subpattern and the definition of the subpattern, compilation crashed with      subpattern and the definition of the subpattern, compilation crashed with
289      an internal error, complaining that it could not find the referenced      an internal error, complaining that it could not find the referenced
290      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.      subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
291      [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
292      over the character class, thus treating the ] as data rather than      over the character class, thus treating the ] as data rather than
293      terminating the class. This meant it could skip too much.]      terminating the class. This meant it could skip too much.]
294    
295  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
296      /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
297      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
298      anchored. Updated pcretest and pcredemo to use this option.      anchored. Updated pcretest and pcredemo to use this option.
299    
300  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
301      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
302      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
303      now given.      now given.
304    
305    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
306        PCRE did not set those parentheses (unlike Perl). I have now found a way to
307        make it do so. The string so far is captured, making this feature
308        compatible with Perl.
309    
310    23. The tests have been re-organized, adding tests 11 and 12, to make it
311        possible to check the Perl 5.10 features against Perl 5.10.
312    
313    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
314        pattern matches a fixed length string. PCRE did not allow this; now it
315        does. Neither allows recursion.
316    
317    25. I finally figured out how to implement a request to provide the minimum
318        length of subject string that was needed in order to match a given pattern.
319        (It was back references and recursion that I had previously got hung up
320        on.) This code has now been added to pcre_study(); it finds a lower bound
321        to the length of subject needed. It is not necessarily the greatest lower
322        bound, but using it to avoid searching strings that are too short does give
323        some useful speed-ups. The value is available to calling programs via
324        pcre_fullinfo().
325    
326    26. While implementing 25, I discovered to my embarrassment that pcretest had
327        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
328        study optimizations had never been tested with that matching function.
329        Oops. What is worse, even when it was passed study data, there was a bug in
330        pcre_dfa_exec() that meant it never actually used it. Double oops. There
331        were also very few tests of studied patterns with pcre_dfa_exec().
332    
333    27. If (?| is used to create subpatterns with duplicate numbers, they are now
334        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
335        on the other side of the coin, they are no longer allowed to have different
336        names, because these cannot be distinguished in PCRE, and this has caused
337        confusion. (This is a difference from Perl.)
338    
339    28. When duplicate subpattern names are present (necessarily with different
340        numbers, as required by 27 above), and a test is made by name in a
341        conditional pattern, either for a subpattern having been matched, or for
342        recursion in such a pattern, all the associated numbered subpatterns are
343        tested, and the overall condition is true if the condition is true for any
344        one of them. This is the way Perl works, and is also more like the way
345        testing by number works.
346    
347    
348  Version 7.9 11-Apr-09  Version 7.9 11-Apr-09
349  ---------------------  ---------------------

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