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

Removed from v.157  
changed lines
  Added in v.300

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