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revision 626 by ph10, Wed Jul 20 17:51:54 2011 UTC revision 659 by ph10, Tue Aug 16 09:48:29 2011 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 30-Apr-2011  Version 8.13 16-Aug-2011
5  ------------------------  ------------------------
6    
7  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 20  Version 8.13 30-Apr-2011 Line 20  Version 8.13 30-Apr-2011
20      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21      2-byte code at the end of the subject (it thought there wasn't enough data      2-byte code at the end of the subject (it thought there wasn't enough data
22      left).      left).
23    
24  5.  Comprehensive information about what went wrong is now returned by  5.  Comprehensive information about what went wrong is now returned by
25      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26      as the output vector has at least 2 elements. The offset of the start of      as the output vector has at least 2 elements. The offset of the start of
27      the failing character and a reason code are placed in the vector.      the failing character and a reason code are placed in the vector.
28    
29  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30      now returned is for the first byte of the failing character, instead of the      now returned is for the first byte of the failing character, instead of the
31      last byte inspected. This is an incompatible change, but I hope it is small      last byte inspected. This is an incompatible change, but I hope it is small
32      enough not to be a problem. It makes the returned offset consistent with      enough not to be a problem. It makes the returned offset consistent with
33      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
34    
35  7.  pcretest now gives a text phrase as well as the error number when  7.  pcretest now gives a text phrase as well as the error number when
36      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37      failure, the offset and reason code are output.      failure, the offset and reason code are output.
38    
39  8.  When \R was used with a maximizing quantifier it failed to skip backwards  8.  When \R was used with a maximizing quantifier it failed to skip backwards
40      over a \r\n pair if the subsequent match failed. Instead, it just skipped      over a \r\n pair if the subsequent match failed. Instead, it just skipped
41      back over a single character (\n). This seems wrong (because it treated the      back over a single character (\n). This seems wrong (because it treated the
42      two characters as a single entity when going forwards), conflicts with the      two characters as a single entity when going forwards), conflicts with the
43      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45      has been changed.      has been changed.
46    
47  9.  Some internal refactoring has changed the processing so that the handling  9.  Some internal refactoring has changed the processing so that the handling
48      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49      time (the PCRE_DOTALL option was changed this way some time ago: version      time (the PCRE_DOTALL option was changed this way some time ago: version
50      7.7 change 16). This has made it possible to abolish the OP_OPT op code,      7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51      which was always a bit of a fudge. It also means that there is one less      which was always a bit of a fudge. It also means that there is one less
52      argument for the match() function, which reduces its stack requirements      argument for the match() function, which reduces its stack requirements
53      slightly. This change also fixes an incompatibility with Perl: the pattern      slightly. This change also fixes an incompatibility with Perl: the pattern
54      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55    
56  10. More internal refactoring has drastically reduced the number of recursive  10. More internal refactoring has drastically reduced the number of recursive
57      calls to match() for possessively repeated groups such as (abc)++ when      calls to match() for possessively repeated groups such as (abc)++ when
58      using pcre_exec().      using pcre_exec().
59    
60  11. While implementing 10, a number of bugs in the handling of groups were  11. While implementing 10, a number of bugs in the handling of groups were
61      discovered and fixed:      discovered and fixed:
62    
63      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64      (a|)*(?1) gave a compile-time internal error.      (a|)*(?1) gave a compile-time internal error.
65      ((a|)+)+  did not notice that the outer group could match an empty string.      ((a|)+)+  did not notice that the outer group could match an empty string.
66      (^a|^)+   was not marked as anchored.      (^a|^)+   was not marked as anchored.
67      (.*a|.*)+ was not marked as matching at start or after a newline.      (.*a|.*)+ was not marked as matching at start or after a newline.
68    
69  12. Yet more internal refactoring has removed another argument from the match()  12. Yet more internal refactoring has removed another argument from the match()
70      function. Special calls to this function are now indicated by setting a      function. Special calls to this function are now indicated by setting a
71      value in a variable in the "match data" data block.      value in a variable in the "match data" data block.
72    
73  13. Be more explicit in pcre_study() instead of relying on "default" for  13. Be more explicit in pcre_study() instead of relying on "default" for
74      opcodes that mean there is no starting character; this means that when new      opcodes that mean there is no starting character; this means that when new
75      ones are added and accidentally left out of pcre_study(), testing should      ones are added and accidentally left out of pcre_study(), testing should
76      pick them up.      pick them up.
77    
78  14. The -s option of pcretest has been documented for ages as being an old  14. The -s option of pcretest has been documented for ages as being an old
79      synonym of -m (show memory usage). I have changed it to mean "force study      synonym of -m (show memory usage). I have changed it to mean "force study
80      for every regex", that is, assume /S for every regex. This is similar to -i      for every regex", that is, assume /S for every regex. This is similar to -i
81      and -d etc. It's slightly incompatible, but I'm hoping nobody is still      and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82      using it. It makes it easier to run collections of tests with and without      using it. It makes it easier to run collections of tests with and without
83      study enabled, and thereby test pcre_study() more easily. All the standard      study enabled, and thereby test pcre_study() more easily. All the standard
84      tests are now run with and without -s (but some patterns can be marked as      tests are now run with and without -s (but some patterns can be marked as
85      "never study" - see 20 below).      "never study" - see 20 below).
86    
87  15. When (*ACCEPT) was used in a subpattern that was called recursively, the  15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88      restoration of the capturing data to the outer values was not happening      restoration of the capturing data to the outer values was not happening
89      correctly.      correctly.
90    
91  16. If a recursively called subpattern ended with (*ACCEPT) and matched an  16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93      pattern had matched an empty string, and so incorrectly returned a no      pattern had matched an empty string, and so incorrectly returned a no
94      match.      match.
95    
96  17. There was optimizing code for the last branch of non-capturing parentheses,  17. There was optimizing code for the last branch of non-capturing parentheses,
97      and also for the obeyed branch of a conditional subexpression, which used      and also for the obeyed branch of a conditional subexpression, which used
98      tail recursion to cut down on stack usage. Unfortunately, not that there is      tail recursion to cut down on stack usage. Unfortunately, now that there is
99      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
100      no longer possible because the return has to be checked for (*THEN). These      no longer possible because the return has to be checked for (*THEN). These
101      two optimizations have therefore been removed.      two optimizations have therefore been removed.
102    
103  18. If a pattern containing \R was studied, it was assumed that \R always  18. If a pattern containing \R was studied, it was assumed that \R always
104      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be
105      incorrectly computed because \R can also match just one byte.      incorrectly computed because \R can also match just one byte.
106    
107  19. If a pattern containing (*ACCEPT) was studied, the minimum subject length  19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108      was incorrectly computed.      was incorrectly computed.
109    
110  20. If /S is present twice on a test pattern in pcretest input, it *disables*  20. If /S is present twice on a test pattern in pcretest input, it now
111      studying, thereby overriding the use of -s on the command line. This is      *disables* studying, thereby overriding the use of -s on the command line
112      necessary for one or two tests to keep the output identical in both cases.      (see 14 above). This is necessary for one or two tests to keep the output
113        identical in both cases.
114    
115  21. When (*ACCEPT) was used in an assertion that matched an empty string and  21. When (*ACCEPT) was used in an assertion that matched an empty string and
116      PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.      PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
117    
118  22. When an atomic group that contained a capturing parenthesis was  22. When an atomic group that contained a capturing parenthesis was
119      successfully matched, but the branch in which it appeared failed, the      successfully matched, but the branch in which it appeared failed, the
120      capturing was not being forgotten if a higher numbered group was later      capturing was not being forgotten if a higher numbered group was later
121      captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing      captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
122      group 1 to "a", when in fact it should be unset. This applied to multi-      group 1 to "a", when in fact it should be unset. This applied to multi-
123      branched capturing and non-capturing groups, repeated or not, and also to      branched capturing and non-capturing groups, repeated or not, and also to
124      positive assertions (capturing in negative assertions is not well defined      positive assertions (capturing in negative assertions does not happen
125      in PCRE) and also to nested atomic groups.      in PCRE) and also to nested atomic groups.
126    
127  23. Add the ++ qualifier feature to pcretest, to show the remainder of the  23. Add the ++ qualifier feature to pcretest, to show the remainder of the
128      subject after a captured substring (to make it easier to tell which of a      subject after a captured substring, to make it easier to tell which of a
129      number of identical substrings has been captured).      number of identical substrings has been captured.
130    
131  24. The way atomic groups are processed by pcre_exec() has been changed so that  24. The way atomic groups are processed by pcre_exec() has been changed so that
132      if they are repeated, backtracking one repetition now resets captured      if they are repeated, backtracking one repetition now resets captured
133      values correctly. For example, if ((?>(a+)b)+aabab) is matched against      values correctly. For example, if ((?>(a+)b)+aabab) is matched against
134      "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as      "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
135      "aaa". Previously, it would have been "a". As part of this code      "aaa". Previously, it would have been "a". As part of this code
136      refactoring, the way recursive calls are handled has also been changed.      refactoring, the way recursive calls are handled has also been changed.
137    
138  24. If an assertion condition captured any substrings, they were not passed  25. If an assertion condition captured any substrings, they were not passed
139      back unless some other capturing happened later. For example, if      back unless some other capturing happened later. For example, if
140      (?(?=(a))a) was matched against "a", no capturing was returned.      (?(?=(a))a) was matched against "a", no capturing was returned.
141    
142  25. When studying a pattern that contained subroutine calls or assertions,  26. When studying a pattern that contained subroutine calls or assertions,
143      the code for finding the minimum length of a possible match was handling      the code for finding the minimum length of a possible match was handling
144      direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where      direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
145      group 1 called group 2 while simultaneously a separate group 2 called group      group 1 called group 2 while simultaneously a separate group 2 called group
146      1). A stack overflow occurred in this case. I have fixed this by limiting      1). A stack overflow occurred in this case. I have fixed this by limiting
147      the recursion depth to 10.      the recursion depth to 10.
148    
149  26. Updated RunTest.bat in the distribution to the version supplied by Tom  27. Updated RunTest.bat in the distribution to the version supplied by Tom
150      Fortmann. This supports explicit test numbers on the command line, and has      Fortmann. This supports explicit test numbers on the command line, and has
151      argument validation and error reporting.      argument validation and error reporting.
152    
153  27. An instance of \X with an unlimited repeat could fail if at any point the  28. An instance of \X with an unlimited repeat could fail if at any point the
154      first character it looked at was a mark character.      first character it looked at was a mark character.
155    
156  28. Some minor code refactoring concerning Unicode properties and scripts  29. Some minor code refactoring concerning Unicode properties and scripts
157      should reduce the stack requirement of match() slightly.      should reduce the stack requirement of match() slightly.
158    
159  29. Added the '=' option to pcretest to check the setting of unused capturing  30. Added the '=' option to pcretest to check the setting of unused capturing
160      slots at the end of the pattern, which are documented as being -1, but are      slots at the end of the pattern, which are documented as being -1, but are
161      not included in the return count.      not included in the return count.
162    
163    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
164        compiled something random. Now it gives a compile-time error (as does
165        Perl).
166    
167    32. A *MARK encountered during the processing of a positive assertion is now
168        recorded and passed back (compatible with Perl).
169    
170    33. If --only-matching or --colour was set on a pcregrep call whose pattern
171        had alternative anchored branches, the search for a second match in a line
172        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
173        matched the line "0102" twice. The same bug affected patterns that started
174        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
175        twice.
176    
177    34. Previously, PCRE did not allow quantification of assertions. However, Perl
178        does, and because of capturing effects, quantifying parenthesized
179        assertions may at times be useful. Quantifiers are now allowed for
180        parenthesized assertions.
181    
182    35. A minor code tidy in pcre_compile() when checking options for \R usage.
183    
184    36. \g was being checked for fancy things in a character class, when it should
185        just be a literal "g".
186    
187    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
188        appearance of a nested POSIX class supersedes an apparent external class.
189        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
190        unescaped square brackets may also appear as part of class names. For
191        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
192        more like Perl.
193    
194    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
195        was because it thought it was \N{name}, which is not supported).
196    
197    39. Add minix to OS list not supporting the -S option in pcretest.
198    
199    40. PCRE tries to detect cases of infinite recursion at compile time, but it
200        cannot analyze patterns in sufficient detail to catch mutual recursions
201        such as ((?1))((?2)). There is now a runtime test that gives an error if a
202        subgroup is called recursively as a subpattern for a second time at the
203        same position in the subject string. In previous releases this might have
204        been caught by the recursion limit, or it might have run out of stack.
205    
206    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
207        happen only once. PCRE was, however incorrectly giving a compile time error
208        "recursive call could loop indefinitely" because it cannot analyze the
209        pattern in sufficient detail. The compile time test no longer happens when
210        PCRE is compiling a conditional subpattern, but actual runaway loops are
211        now caught at runtime (see 40 above).
212    
213    42. It seems that Perl allows any characters other than a closing parenthesis
214        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
215        has been changed to be the same.
216    
217    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
218        as not to get warnings when autogen.sh is called. Also changed
219        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
220    
221    44. To help people who use pcregrep to scan files containing exceedingly long
222        lines, the following changes have been made:
223    
224        (a) The default value of the buffer size parameter has been increased from
225            8K to 20K. (The actual buffer used is three times this size.)
226    
227        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
228            PCRE is built.
229    
230        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
231            to be set at run time.
232    
233        (d) Numerical values in pcregrep options can be followed by K or M, for
234            example --buffer-size=50K.
235    
236        (e) If a line being scanned overflows pcregrep's buffer, an error is now
237            given and the return code is set to 2.
238    
239    45. Add a pointer to the latest mark to the callout data block.
240    
241    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
242        partial match of an empty string instead of no match. This was specific to
243        the use of ".".
244    
245    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
246        complete match instead of a partial match. This bug was dependent on both
247        the PCRE_UTF8 and PCRE_DOTALL options being set.
248    
249    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
250        starting byte set, because \b was not being ignored.
251    
252    
253  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011

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