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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 13-June-07  Version 7.6 19-Jan-08
5    ---------------------
6    
7    1.  A character class containing a very large number of characters with
8        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
9        overflow.
10    
11    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
12        HAVE_LONG_LONG is not defined.
13    
14    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
15        bring them up to date and include new features.
16    
17    
18    Version 7.5 10-Jan-08
19    ---------------------
20    
21    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
22        values in parens when parsing an RE using the C++ wrapper."
23    
24    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
25        Characters greater than 255 were excluded from the class instead of being
26        included.
27    
28    3.  The same bug as (2) above applied to negated POSIX classes such as
29        [:^space:].
30    
31    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
32        defined or documented. It seems to have been a typo for PCRE_STATIC, so
33        I have changed it.
34    
35    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
36        first named subpattern) and a construct such as (?&a) would reference the
37        first named subpattern whose name started with "a" (in other words, the
38        length check was missing). Both these problems are fixed. "Subpattern name
39        expected" is now given for (?&) (a zero-length name), and this patch also
40        makes it give the same error for \k'' (previously it complained that that
41        was a reference to a non-existent subpattern).
42    
43    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
44        this is right because (?- can be followed by option settings as well as by
45        digits. I have, however, made the messages clearer.
46    
47    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
48        than the number used in the conditional) now cause a compile-time error.
49        This is actually not compatible with Perl, which accepts such patterns, but
50        treats the conditional as always being FALSE (as PCRE used to), but it
51        seems to me that giving a diagnostic is better.
52    
53    8.  Change "alphameric" to the more common word "alphanumeric" in comments
54        and messages.
55    
56    9.  Fix two occurrences of "backslash" in comments that should have been
57        "backspace".
58    
59    10. Remove two redundant lines of code that can never be obeyed (their function
60        was moved elsewhere).
61    
62    11. The program that makes PCRE's Unicode character property table had a bug
63        which caused it to generate incorrect table entries for sequences of
64        characters that have the same character type, but are in different scripts.
65        It amalgamated them into a single range, with the script of the first of
66        them. In other words, some characters were in the wrong script. There were
67        thirteen such cases, affecting characters in the following ranges:
68    
69          U+002b0 - U+002c1
70          U+0060c - U+0060d
71          U+0061e - U+00612
72          U+0064b - U+0065e
73          U+0074d - U+0076d
74          U+01800 - U+01805
75          U+01d00 - U+01d77
76          U+01d9b - U+01dbf
77          U+0200b - U+0200f
78          U+030fc - U+030fe
79          U+03260 - U+0327f
80          U+0fb46 - U+0fbb1
81          U+10450 - U+1049d
82    
83    12. The -o option (show only the matching part of a line) for pcregrep was not
84        compatible with GNU grep in that, if there was more than one match in a
85        line, it showed only the first of them. It now behaves in the same way as
86        GNU grep.
87    
88    13. If the -o and -v options were combined for pcregrep, it printed a blank
89        line for every non-matching line. GNU grep prints nothing, and pcregrep now
90        does the same. The return code can be used to tell if there were any
91        non-matching lines.
92    
93    14. Added --file-offsets and --line-offsets to pcregrep.
94    
95    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
96        infinitely looping recursion. The bug was that positive lookaheads were not
97        being skipped when checking for a possible empty match (negative lookaheads
98        and both kinds of lookbehind were skipped).
99    
100    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
101        inclusion of <windows.h> to before rather than after the definition of
102        INVALID_FILE_ATTRIBUTES (patch from David Byron).
103    
104    17. Specifying a possessive quantifier with a specific limit for a Unicode
105        character property caused pcre_compile() to compile bad code, which led at
106        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
107        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
108        caused the error; without that there was no problem.
109    
110    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
111    
112    19. Added --enable-pcretest-libreadline.
113    
114    20. In pcrecpp.cc, the variable 'count' was incremented twice in
115        RE::GlobalReplace(). As a result, the number of replacements returned was
116        double what it should be. I removed one of the increments, but Craig sent a
117        later patch that removed the other one (the right fix) and added unit tests
118        that check the return values (which was not done before).
119    
120    21. Several CMake things:
121    
122        (1) Arranged that, when cmake is used on Unix, the libraries end up with
123            the names libpcre and libpcreposix, not just pcre and pcreposix.
124    
125        (2) The above change means that pcretest and pcregrep are now correctly
126            linked with the newly-built libraries, not previously installed ones.
127    
128        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
129    
130    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
131        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
132        UTF-8 newline character). The key issue is that the pattern starts .*;
133        this means that the match must be either at the beginning, or after a
134        newline. The bug was in the code for advancing after a failed match and
135        checking that the new position followed a newline. It was not taking
136        account of UTF-8 characters correctly.
137    
138    23. PCRE was behaving differently from Perl in the way it recognized POSIX
139        character classes. PCRE was not treating the sequence [:...:] as a
140        character class unless the ... were all letters. Perl, however, seems to
141        allow any characters between [: and :], though of course it rejects as
142        unknown any "names" that contain non-letters, because all the known class
143        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
144        for example, whereas PCRE did not - it did not recognize a POSIX character
145        class. This seemed a bit dangerous, so the code has been changed to be
146        closer to Perl. The behaviour is not identical to Perl, because PCRE will
147        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
148        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
149        Perl does, and where it didn't before.
150    
151    24. Rewrite so as to remove the single use of %n from pcregrep because in some
152        Windows environments %n is disabled by default.
153    
154    
155    Version 7.4 21-Sep-07
156    ---------------------
157    
158    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
159        means that a class such as [\s] counted as "explicit reference to CR or
160        LF". That isn't really right - the whole point of the change was to try to
161        help when there was an actual mention of one of the two characters. So now
162        the change happens only if \r or \n (or a literal CR or LF) character is
163        encountered.
164    
165    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
166        of both had grown to the point where there were only 3 bits left.
167        Fortunately, there was spare space in the data structure, and so I have
168        moved the internal flags into a new 16-bit field to free up more option
169        bits.
170    
171    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
172        but did not set the internal JCHANGED flag - either of these is enough to
173        control the way the "get" function works - but the PCRE_INFO_JCHANGED
174        facility is supposed to tell if (?J) was ever used, so now (?J) at the
175        start sets both bits.
176    
177    4.  Added options (at build time, compile time, exec time) to change \R from
178        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
179    
180    5.  doc/pcresyntax.html was missing from the distribution.
181    
182    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
183        compatibility, even though it is no longer used.
184    
185    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
186        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
187        windows.h file is present (where different names are used). [This was
188        reversed later after testing - see 16 below.]
189    
190    8.  Changed all #include <config.h> to #include "config.h". There were also
191        some further <pcre.h> cases that I changed to "pcre.h".
192    
193    9.  When pcregrep was used with the --colour option, it missed the line ending
194        sequence off the lines that it output.
195    
196    10. It was pointed out to me that arrays of string pointers cause lots of
197        relocations when a shared library is dynamically loaded. A technique of
198        using a single long string with a table of offsets can drastically reduce
199        these. I have refactored PCRE in four places to do this. The result is
200        dramatic:
201    
202          Originally:                          290
203          After changing UCP table:            187
204          After changing error message table:   43
205          After changing table of "verbs"       36
206          After changing table of Posix names   22
207    
208        Thanks to the folks working on Gregex for glib for this insight.
209    
210    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
211        unicode-properties was also set.
212    
213    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
214    
215    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
216        checked only for CRLF.
217    
218    14. Added casts to pcretest.c to avoid compiler warnings.
219    
220    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
221    
222    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
223        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
224        entirely. This removes changes made in 7 above.
225    
226    17. The CMake files have been updated, and there is now more information about
227        building with CMake in the NON-UNIX-USE document.
228    
229    
230    Version 7.3 28-Aug-07
231    ---------------------
232    
233     1. In the rejigging of the build system that eventually resulted in 7.1, the
234        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
235        brackets there is not right, since it causes compilers to look for an
236        installed pcre.h, not the version that is in the source that is being
237        compiled (which of course may be different). I have changed it back to:
238    
239          #include "pcre.h"
240    
241        I have a vague recollection that the change was concerned with compiling in
242        different directories, but in the new build system, that is taken care of
243        by the VPATH setting the Makefile.
244    
245     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
246        when the subject happened to end in the byte 0x85 (e.g. if the last
247        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
248        characters but of course it shouldn't be taken as a newline when it is part
249        of another character. The bug was that, for an unlimited repeat of . in
250        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
251        characters when looking for a newline.
252    
253     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
254    
255     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
256        in debug output.
257    
258     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
259        long printing in the pcrecpp unittest when running under MinGW.
260    
261     6. ESC_K was left out of the EBCDIC table.
262    
263     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
264        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
265        limit also applies to "virtual nesting" when a pattern is recursive, and in
266        this case 1000 isn't so big. I have been able to remove this limit at the
267        expense of backing off one optimization in certain circumstances. Normally,
268        when pcre_exec() would call its internal match() function recursively and
269        immediately return the result unconditionally, it uses a "tail recursion"
270        feature to save stack. However, when a subpattern that can match an empty
271        string has an unlimited repetition quantifier, it no longer makes this
272        optimization. That gives it a stack frame in which to save the data for
273        checking that an empty string has been matched. Previously this was taken
274        from the 1000-entry workspace that had been reserved. So now there is no
275        explicit limit, but more stack is used.
276    
277     8. Applied Daniel's patches to solve problems with the import/export magic
278        syntax that is required for Windows, and which was going wrong for the
279        pcreposix and pcrecpp parts of the library. These were overlooked when this
280        problem was solved for the main library.
281    
282     9. There were some crude static tests to avoid integer overflow when computing
283        the size of patterns that contain repeated groups with explicit upper
284        limits. As the maximum quantifier is 65535, the maximum group length was
285        set at 30,000 so that the product of these two numbers did not overflow a
286        32-bit integer. However, it turns out that people want to use groups that
287        are longer than 30,000 bytes (though not repeat them that many times).
288        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
289        made it possible to implement the integer overflow checks in a much more
290        dynamic way, which I have now done. The artificial limitation on group
291        length has been removed - we now have only the limit on the total length of
292        the compiled pattern, which depends on the LINK_SIZE setting.
293    
294    10. Fixed a bug in the documentation for get/copy named substring when
295        duplicate names are permitted. If none of the named substrings are set, the
296        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
297        empty string.
298    
299    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
300        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
301        because the ] is interpreted as the first data character and the
302        terminating ] is not found. PCRE has been made compatible with Perl in this
303        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
304        cause memory overwriting.
305    
306    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
307        string has been matched (to stop an infinite loop). It was not recognizing
308        a conditional subpattern that could match an empty string if that
309        subpattern was within another subpattern. For example, it looped when
310        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
311        condition was not nested. This bug has been fixed.
312    
313    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
314        past the start of the subject in the presence of bytes with the top bit
315        set, for example "\x8aBCD".
316    
317    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
318        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
319    
320    14. Optimized (?!) to (*FAIL).
321    
322    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
323        This restricts code points to be within the range 0 to 0x10FFFF, excluding
324        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
325        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
326        does: it's just the validity check that is more restrictive.
327    
328    16. Inserted checks for integer overflows during escape sequence (backslash)
329        processing, and also fixed erroneous offset values for syntax errors during
330        backslash processing.
331    
332    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
333        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
334    
335    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
336        caused an overrun.
337    
338    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
339        something other than just ASCII characters) inside a group that had an
340        unlimited repeat caused a loop at compile time (while checking to see
341        whether the group could match an empty string).
342    
343    20. Debugging a pattern containing \p or \P could cause a crash. For example,
344        [\P{Any}] did so. (Error in the code for printing property names.)
345    
346    21. An orphan \E inside a character class could cause a crash.
347    
348    22. A repeated capturing bracket such as (A)? could cause a wild memory
349        reference during compilation.
350    
351    23. There are several functions in pcre_compile() that scan along a compiled
352        expression for various reasons (e.g. to see if it's fixed length for look
353        behind). There were bugs in these functions when a repeated \p or \P was
354        present in the pattern. These operators have additional parameters compared
355        with \d, etc, and these were not being taken into account when moving along
356        the compiled data. Specifically:
357    
358        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
359            length.
360    
361        (b) An item such as \pL+ within a repeated group could cause crashes or
362            loops.
363    
364        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
365            "reference to non-existent subpattern" error.
366    
367        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
368    
369    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
370        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
371    
372    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
373    
374    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
375        character were causing crashes (broken optimization).
376    
377    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
378        \p or \P) caused a compile-time loop.
379    
380    28. More problems have arisen in unanchored patterns when CRLF is a valid line
381        break. For example, the unstudied pattern [\r\n]A does not match the string
382        "\r\nA" because change 7.0/46 below moves the current point on by two
383        characters after failing to match at the start. However, the pattern \nA
384        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
385        the same is true. There doesn't seem any very clean way out of this, but
386        what I have chosen to do makes the common cases work: PCRE now takes note
387        of whether there can be an explicit match for \r or \n anywhere in the
388        pattern, and if so, 7.0/46 no longer applies. As part of this change,
389        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
390        pattern has explicit CR or LF references.
391    
392    29. Added (*CR) etc for changing newline setting at start of pattern.
393    
394    
395    Version 7.2 19-Jun-07
396  ---------------------  ---------------------
397    
398   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 40  Version 7.2 13-June-07 Line 431  Version 7.2 13-June-07
431    
432      (f) \g{name} is another synonym - part of Perl 5.10's unification of      (f) \g{name} is another synonym - part of Perl 5.10's unification of
433          reference syntax.          reference syntax.
434    
435      (g) (?| introduces a group in which the numbering of parentheses in each      (g) (?| introduces a group in which the numbering of parentheses in each
436          alternative starts with the same number.          alternative starts with the same number.
437    
438      (h) \h, \H, \v, and \V match horizontal and vertical whitespace.      (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
439    
440   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and   7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
441      PCRE_INFO_JCHANGED.      PCRE_INFO_JCHANGED.
# Line 59  Version 7.2 13-June-07 Line 450  Version 7.2 13-June-07
450      bit of new cunning has reduced the workspace needed for groups with      bit of new cunning has reduced the workspace needed for groups with
451      alternatives. The 1000-alternative test pattern now uses 12 bytes of      alternatives. The 1000-alternative test pattern now uses 12 bytes of
452      workspace instead of running out of the 4096 that are available.      workspace instead of running out of the 4096 that are available.
453    
454  10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.  10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
455    
456  11. Applied patch from Google to remove an optimization that didn't quite work.  11. Applied patch from Google to remove an optimization that didn't quite work.
457      The report of the bug said:      The report of the bug said:
458    
459        pcrecpp::RE("a*").FullMatch("aaa") matches, while        pcrecpp::RE("a*").FullMatch("aaa") matches, while
460        pcrecpp::RE("a*?").FullMatch("aaa") does not, and        pcrecpp::RE("a*?").FullMatch("aaa") does not, and
461        pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.        pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
462    
463    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
464        it matched the wrong number of bytes.
465    
466    
467  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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