ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 87 by nigel, Sat Feb 24 21:41:21 2007 UTC revision 356 by ph10, Tue Jul 8 14:14:34 2008 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.0 02 Jul-08
5    ---------------------
7    1.  Replaced UCP searching code with optimized version as implemented for Ad
8        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9        stage table and inline lookup instead of a function, giving speed ups of 2
10        to 5 times on some simple patterns that I tested. Permission was given to
11        distribute the MultiStage2.py script that generates the tables (it's not in
12        the tarball, but is in the Subversion repository).
14    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15        scripts.
17    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18        a group with a zero qualifier. The result of the study could be incorrect,
19        or the function might crash, depending on the pattern.
21    4.  Caseless matching was not working for non-ASCII characters in back
22        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23        It now works when Unicode Property Support is available.
25    5.  In pcretest, an escape such as \x{de} in the data was always generating
26        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28        truncation.
30    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
33    Version 7.7 07-May-08
34    ---------------------
36    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
37        a string to a long long, pretend we don't even have a long long." This is
38        done by checking for the strtoq, strtoll, and _strtoi64 functions.
40    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
41        pre-7.6 versions, which defined a global no_arg variable instead of putting
42        it in the RE class. (See also #8 below.)
44    3.  Remove a line of dead code, identified by coverity and reported by Nuno
45        Lopes.
47    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
49        (1) The include/exclude patterns were being applied to the whole pathnames
50            of files, instead of just to the final components.
52        (2) If there was more than one level of directory, the subdirectories were
53            skipped unless they satisfied the include/exclude conditions. This is
54            inconsistent with GNU grep (and could even be seen as contrary to the
55            pcregrep specification - which I improved to make it absolutely clear).
56            The action now is always to scan all levels of directory, and just
57            apply the include/exclude patterns to regular files.
59    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
60        --exclude_dir in the tests to avoid scanning .svn directories.
62    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
63        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
64        doesn't support NULs in patterns.
66    7.  Added some missing "const"s to declarations of static tables in
67        pcre_compile.c and pcre_dfa_exec.c.
69    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
70        caused by fix #2  above. (Subsequently also a second patch to fix the
71        first patch. And a third patch - this was a messy problem.)
73    9.  Applied Craig's patch to remove the use of push_back().
75    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
76        matching function regexec().
78    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
79        which, however, unlike Perl's \g{...}, are subroutine calls, not back
80        references. PCRE supports relative numbers with this syntax (I don't think
81        Oniguruma does).
83    12. Previously, a group with a zero repeat such as (...){0} was completely
84        omitted from the compiled regex. However, this means that if the group
85        was called as a subroutine from elsewhere in the pattern, things went wrong
86        (an internal error was given). Such groups are now left in the compiled
87        pattern, with a new opcode that causes them to be skipped at execution
88        time.
90    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
91        to the way PCRE behaves:
93        (a) A lone ] character is dis-allowed (Perl treats it as data).
95        (b) A back reference to an unmatched subpattern matches an empty string
96            (Perl fails the current match path).
98        (c) A data ] in a character class must be notated as \] because if the
99            first data character in a class is ], it defines an empty class. (In
100            Perl it is not possible to have an empty class.) The empty class []
101            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
102            The negative empty class [^] matches any one character, independently
103            of the DOTALL setting.
105    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
106        non-existent subpattern following a character class starting with ']' and
107        containing () gave an internal compiling error instead of "reference to
108        non-existent subpattern". Fortunately, when the pattern did exist, the
109        compiled code was correct. (When scanning forwards to check for the
110        existencd of the subpattern, it was treating the data ']' as terminating
111        the class, so got the count wrong. When actually compiling, the reference
112        was subsequently set up correctly.)
114    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
115        it was being rejected as not supported by pcre_dfa_exec(), even though
116        other assertions are supported. I have made pcre_dfa_exec() support
117        (*FAIL).
119    16. The implementation of 13c above involved the invention of a new opcode,
120        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
121        cannot be changed at match time, I realized I could make a small
122        improvement to matching performance by compiling OP_ALLANY instead of
123        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
124        on the OP_ANY path.
126    17. Compiling pcretest on Windows with readline support failed without the
127        following two fixes: (1) Make the unistd.h include conditional on
128        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
130    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
131        ncurses library to be included for pcretest when ReadLine support is
132        requested, but also to allow for it to be overridden. This patch came from
133        Daniel Bergström.
135    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
136        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
137        any errors with the current Unicode tables. Thanks to Peter Kankowski for
138        spotting this.
141    Version 7.6 28-Jan-08
142    ---------------------
144    1.  A character class containing a very large number of characters with
145        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
146        overflow.
148    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
149        HAVE_LONG_LONG is not defined.
151    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
152        bring them up to date and include new features. This patch includes:
154        - Fixed PH's badly added libz and libbz2 support.
155        - Fixed a problem with static linking.
156        - Added pcredemo. [But later removed - see 7 below.]
157        - Fixed dftables problem and added an option.
158        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
159            HAVE_LONG_LONG.
160        - Added readline support for pcretest.
161        - Added an listing of the option settings after cmake has run.
163    4.  A user submitted a patch to Makefile that makes it easy to create
164        "pcre.dll" under mingw when using Configure/Make. I added stuff to
165        Makefile.am that cause it to include this special target, without
166        affecting anything else. Note that the same mingw target plus all
167        the other distribution libraries and programs are now supported
168        when configuring with CMake (see 6 below) instead of with
169        Configure/Make.
171    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
172        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
173        exported in the Windows port". It has not yet been confirmed that the patch
174        solves the problem, but it does no harm.
176    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
177        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
178        with CMake, and also correct the comment about stack recursion.
180    7.  Remove the automatic building of pcredemo from the ./configure system and
181        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
182        of a program that users should build themselves after PCRE is installed, so
183        building it automatically is not really right. What is more, it gave
184        trouble in some build environments.
186    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
189    Version 7.5 10-Jan-08
190    ---------------------
192    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
193        values in parens when parsing an RE using the C++ wrapper."
195    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
196        Characters greater than 255 were excluded from the class instead of being
197        included.
199    3.  The same bug as (2) above applied to negated POSIX classes such as
200        [:^space:].
202    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
203        defined or documented. It seems to have been a typo for PCRE_STATIC, so
204        I have changed it.
206    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
207        first named subpattern) and a construct such as (?&a) would reference the
208        first named subpattern whose name started with "a" (in other words, the
209        length check was missing). Both these problems are fixed. "Subpattern name
210        expected" is now given for (?&) (a zero-length name), and this patch also
211        makes it give the same error for \k'' (previously it complained that that
212        was a reference to a non-existent subpattern).
214    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
215        this is right because (?- can be followed by option settings as well as by
216        digits. I have, however, made the messages clearer.
218    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
219        than the number used in the conditional) now cause a compile-time error.
220        This is actually not compatible with Perl, which accepts such patterns, but
221        treats the conditional as always being FALSE (as PCRE used to), but it
222        seems to me that giving a diagnostic is better.
224    8.  Change "alphameric" to the more common word "alphanumeric" in comments
225        and messages.
227    9.  Fix two occurrences of "backslash" in comments that should have been
228        "backspace".
230    10. Remove two redundant lines of code that can never be obeyed (their function
231        was moved elsewhere).
233    11. The program that makes PCRE's Unicode character property table had a bug
234        which caused it to generate incorrect table entries for sequences of
235        characters that have the same character type, but are in different scripts.
236        It amalgamated them into a single range, with the script of the first of
237        them. In other words, some characters were in the wrong script. There were
238        thirteen such cases, affecting characters in the following ranges:
240          U+002b0 - U+002c1
241          U+0060c - U+0060d
242          U+0061e - U+00612
243          U+0064b - U+0065e
244          U+0074d - U+0076d
245          U+01800 - U+01805
246          U+01d00 - U+01d77
247          U+01d9b - U+01dbf
248          U+0200b - U+0200f
249          U+030fc - U+030fe
250          U+03260 - U+0327f
251          U+0fb46 - U+0fbb1
252          U+10450 - U+1049d
254    12. The -o option (show only the matching part of a line) for pcregrep was not
255        compatible with GNU grep in that, if there was more than one match in a
256        line, it showed only the first of them. It now behaves in the same way as
257        GNU grep.
259    13. If the -o and -v options were combined for pcregrep, it printed a blank
260        line for every non-matching line. GNU grep prints nothing, and pcregrep now
261        does the same. The return code can be used to tell if there were any
262        non-matching lines.
264    14. Added --file-offsets and --line-offsets to pcregrep.
266    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
267        infinitely looping recursion. The bug was that positive lookaheads were not
268        being skipped when checking for a possible empty match (negative lookaheads
269        and both kinds of lookbehind were skipped).
271    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
272        inclusion of <windows.h> to before rather than after the definition of
273        INVALID_FILE_ATTRIBUTES (patch from David Byron).
275    17. Specifying a possessive quantifier with a specific limit for a Unicode
276        character property caused pcre_compile() to compile bad code, which led at
277        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
278        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
279        caused the error; without that there was no problem.
281    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
283    19. Added --enable-pcretest-libreadline.
285    20. In pcrecpp.cc, the variable 'count' was incremented twice in
286        RE::GlobalReplace(). As a result, the number of replacements returned was
287        double what it should be. I removed one of the increments, but Craig sent a
288        later patch that removed the other one (the right fix) and added unit tests
289        that check the return values (which was not done before).
291    21. Several CMake things:
293        (1) Arranged that, when cmake is used on Unix, the libraries end up with
294            the names libpcre and libpcreposix, not just pcre and pcreposix.
296        (2) The above change means that pcretest and pcregrep are now correctly
297            linked with the newly-built libraries, not previously installed ones.
301    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
302        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
303        UTF-8 newline character). The key issue is that the pattern starts .*;
304        this means that the match must be either at the beginning, or after a
305        newline. The bug was in the code for advancing after a failed match and
306        checking that the new position followed a newline. It was not taking
307        account of UTF-8 characters correctly.
309    23. PCRE was behaving differently from Perl in the way it recognized POSIX
310        character classes. PCRE was not treating the sequence [:...:] as a
311        character class unless the ... were all letters. Perl, however, seems to
312        allow any characters between [: and :], though of course it rejects as
313        unknown any "names" that contain non-letters, because all the known class
314        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
315        for example, whereas PCRE did not - it did not recognize a POSIX character
316        class. This seemed a bit dangerous, so the code has been changed to be
317        closer to Perl. The behaviour is not identical to Perl, because PCRE will
318        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
319        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
320        Perl does, and where it didn't before.
322    24. Rewrite so as to remove the single use of %n from pcregrep because in some
323        Windows environments %n is disabled by default.
326    Version 7.4 21-Sep-07
327    ---------------------
329    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
330        means that a class such as [\s] counted as "explicit reference to CR or
331        LF". That isn't really right - the whole point of the change was to try to
332        help when there was an actual mention of one of the two characters. So now
333        the change happens only if \r or \n (or a literal CR or LF) character is
334        encountered.
336    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
337        of both had grown to the point where there were only 3 bits left.
338        Fortunately, there was spare space in the data structure, and so I have
339        moved the internal flags into a new 16-bit field to free up more option
340        bits.
342    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
343        but did not set the internal JCHANGED flag - either of these is enough to
344        control the way the "get" function works - but the PCRE_INFO_JCHANGED
345        facility is supposed to tell if (?J) was ever used, so now (?J) at the
346        start sets both bits.
348    4.  Added options (at build time, compile time, exec time) to change \R from
349        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
351    5.  doc/pcresyntax.html was missing from the distribution.
353    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
354        compatibility, even though it is no longer used.
356    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
357        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
358        windows.h file is present (where different names are used). [This was
359        reversed later after testing - see 16 below.]
361    8.  Changed all #include <config.h> to #include "config.h". There were also
362        some further <pcre.h> cases that I changed to "pcre.h".
364    9.  When pcregrep was used with the --colour option, it missed the line ending
365        sequence off the lines that it output.
367    10. It was pointed out to me that arrays of string pointers cause lots of
368        relocations when a shared library is dynamically loaded. A technique of
369        using a single long string with a table of offsets can drastically reduce
370        these. I have refactored PCRE in four places to do this. The result is
371        dramatic:
373          Originally:                          290
374          After changing UCP table:            187
375          After changing error message table:   43
376          After changing table of "verbs"       36
377          After changing table of Posix names   22
379        Thanks to the folks working on Gregex for glib for this insight.
381    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
382        unicode-properties was also set.
384    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
386    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
387        checked only for CRLF.
389    14. Added casts to pcretest.c to avoid compiler warnings.
391    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
393    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
394        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
395        entirely. This removes changes made in 7 above.
397    17. The CMake files have been updated, and there is now more information about
398        building with CMake in the NON-UNIX-USE document.
401    Version 7.3 28-Aug-07
402    ---------------------
404     1. In the rejigging of the build system that eventually resulted in 7.1, the
405        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
406        brackets there is not right, since it causes compilers to look for an
407        installed pcre.h, not the version that is in the source that is being
408        compiled (which of course may be different). I have changed it back to:
410          #include "pcre.h"
412        I have a vague recollection that the change was concerned with compiling in
413        different directories, but in the new build system, that is taken care of
414        by the VPATH setting the Makefile.
416     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
417        when the subject happened to end in the byte 0x85 (e.g. if the last
418        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
419        characters but of course it shouldn't be taken as a newline when it is part
420        of another character. The bug was that, for an unlimited repeat of . in
421        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
422        characters when looking for a newline.
424     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
426     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
427        in debug output.
429     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
430        long printing in the pcrecpp unittest when running under MinGW.
432     6. ESC_K was left out of the EBCDIC table.
434     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
435        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
436        limit also applies to "virtual nesting" when a pattern is recursive, and in
437        this case 1000 isn't so big. I have been able to remove this limit at the
438        expense of backing off one optimization in certain circumstances. Normally,
439        when pcre_exec() would call its internal match() function recursively and
440        immediately return the result unconditionally, it uses a "tail recursion"
441        feature to save stack. However, when a subpattern that can match an empty
442        string has an unlimited repetition quantifier, it no longer makes this
443        optimization. That gives it a stack frame in which to save the data for
444        checking that an empty string has been matched. Previously this was taken
445        from the 1000-entry workspace that had been reserved. So now there is no
446        explicit limit, but more stack is used.
448     8. Applied Daniel's patches to solve problems with the import/export magic
449        syntax that is required for Windows, and which was going wrong for the
450        pcreposix and pcrecpp parts of the library. These were overlooked when this
451        problem was solved for the main library.
453     9. There were some crude static tests to avoid integer overflow when computing
454        the size of patterns that contain repeated groups with explicit upper
455        limits. As the maximum quantifier is 65535, the maximum group length was
456        set at 30,000 so that the product of these two numbers did not overflow a
457        32-bit integer. However, it turns out that people want to use groups that
458        are longer than 30,000 bytes (though not repeat them that many times).
459        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
460        made it possible to implement the integer overflow checks in a much more
461        dynamic way, which I have now done. The artificial limitation on group
462        length has been removed - we now have only the limit on the total length of
463        the compiled pattern, which depends on the LINK_SIZE setting.
465    10. Fixed a bug in the documentation for get/copy named substring when
466        duplicate names are permitted. If none of the named substrings are set, the
467        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
468        empty string.
470    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
471        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
472        because the ] is interpreted as the first data character and the
473        terminating ] is not found. PCRE has been made compatible with Perl in this
474        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
475        cause memory overwriting.
477    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
478        string has been matched (to stop an infinite loop). It was not recognizing
479        a conditional subpattern that could match an empty string if that
480        subpattern was within another subpattern. For example, it looped when
481        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
482        condition was not nested. This bug has been fixed.
484    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
485        past the start of the subject in the presence of bytes with the top bit
486        set, for example "\x8aBCD".
488    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
489        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
491    14. Optimized (?!) to (*FAIL).
493    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
494        This restricts code points to be within the range 0 to 0x10FFFF, excluding
495        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
496        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
497        does: it's just the validity check that is more restrictive.
499    16. Inserted checks for integer overflows during escape sequence (backslash)
500        processing, and also fixed erroneous offset values for syntax errors during
501        backslash processing.
503    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
504        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
506    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
507        caused an overrun.
509    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
510        something other than just ASCII characters) inside a group that had an
511        unlimited repeat caused a loop at compile time (while checking to see
512        whether the group could match an empty string).
514    20. Debugging a pattern containing \p or \P could cause a crash. For example,
515        [\P{Any}] did so. (Error in the code for printing property names.)
517    21. An orphan \E inside a character class could cause a crash.
519    22. A repeated capturing bracket such as (A)? could cause a wild memory
520        reference during compilation.
522    23. There are several functions in pcre_compile() that scan along a compiled
523        expression for various reasons (e.g. to see if it's fixed length for look
524        behind). There were bugs in these functions when a repeated \p or \P was
525        present in the pattern. These operators have additional parameters compared
526        with \d, etc, and these were not being taken into account when moving along
527        the compiled data. Specifically:
529        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
530            length.
532        (b) An item such as \pL+ within a repeated group could cause crashes or
533            loops.
535        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
536            "reference to non-existent subpattern" error.
538        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
540    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
541        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
543    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
545    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
546        character were causing crashes (broken optimization).
548    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
549        \p or \P) caused a compile-time loop.
551    28. More problems have arisen in unanchored patterns when CRLF is a valid line
552        break. For example, the unstudied pattern [\r\n]A does not match the string
553        "\r\nA" because change 7.0/46 below moves the current point on by two
554        characters after failing to match at the start. However, the pattern \nA
555        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
556        the same is true. There doesn't seem any very clean way out of this, but
557        what I have chosen to do makes the common cases work: PCRE now takes note
558        of whether there can be an explicit match for \r or \n anywhere in the
559        pattern, and if so, 7.0/46 no longer applies. As part of this change,
560        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
561        pattern has explicit CR or LF references.
563    29. Added (*CR) etc for changing newline setting at start of pattern.
566    Version 7.2 19-Jun-07
567    ---------------------
569     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
570        which is apparently normally available under Windows.
572     2. Re-jig the pcregrep tests with different newline settings in an attempt
573        to make them independent of the local environment's newline setting.
575     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
577     4. Some of the "internals" tests were previously cut out when the link size
578        was not 2, because the output contained actual offsets. The recent new
579        "Z" feature of pcretest means that these can be cut out, making the tests
580        usable with all link sizes.
582     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
583        stack recursion. This gives a massive performance boost under BSD, but just
584        a small improvement under Linux. However, it saves one field in the frame
585        in all cases.
587     6. Added more features from the forthcoming Perl 5.10:
589        (a) (?-n) (where n is a string of digits) is a relative subroutine or
590            recursion call. It refers to the nth most recently opened parentheses.
592        (b) (?+n) is also a relative subroutine call; it refers to the nth next
593            to be opened parentheses.
595        (c) Conditions that refer to capturing parentheses can be specified
596            relatively, for example, (?(-2)... or (?(+3)...
598        (d) \K resets the start of the current match so that everything before
599            is not part of it.
601        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
603        (f) \g{name} is another synonym - part of Perl 5.10's unification of
604            reference syntax.
606        (g) (?| introduces a group in which the numbering of parentheses in each
607            alternative starts with the same number.
609        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
611     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
614     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
615        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
616        for detecting groups that can match an empty string.
618     9. A pattern with a very large number of alternatives (more than several
619        hundred) was running out of internal workspace during the pre-compile
620        phase, where pcre_compile() figures out how much memory will be needed. A
621        bit of new cunning has reduced the workspace needed for groups with
622        alternatives. The 1000-alternative test pattern now uses 12 bytes of
623        workspace instead of running out of the 4096 that are available.
625    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
627    11. Applied patch from Google to remove an optimization that didn't quite work.
628        The report of the bug said:
630          pcrecpp::RE("a*").FullMatch("aaa") matches, while
631          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
632          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
634    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
635        it matched the wrong number of bytes.
638    Version 7.1 24-Apr-07
639    ---------------------
641     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
642        that is more "standard", making use of automake and other Autotools. There
643        is some re-arrangement of the files and adjustment of comments consequent
644        on this.
646     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
647        for recursive directory scanning broke on some systems because the files
648        are not scanned in any specific order and on different systems the order
649        was different. A call to "sort" has been inserted into RunGrepTest for the
650        approprate test as a short-term fix. In the longer term there may be an
651        alternative.
653     3. I had an email from Eric Raymond about problems translating some of PCRE's
654        man pages to HTML (despite the fact that I distribute HTML pages, some
655        people do their own conversions for various reasons). The problems
656        concerned the use of low-level troff macros .br and .in. I have therefore
657        removed all such uses from the man pages (some were redundant, some could
658        be replaced by .nf/.fi pairs). The 132html script that I use to generate
659        HTML has been updated to handle .nf/.fi and to complain if it encounters
660        .br or .in.
662     4. Updated comments in configure.ac that get placed in config.h.in and also
663        arranged for config.h to be included in the distribution, with the name
664        config.h.generic, for the benefit of those who have to compile without
665        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
667     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
668        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
669        makevp.bat for the current PCRE, using the additional files
670        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
672     6. A Windows user reported a minor discrepancy with test 2, which turned out
673        to be caused by a trailing space on an input line that had got lost in his
674        copy. The trailing space was an accident, so I've just removed it.
676     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
677        that is needed.
679     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
680        as "const" (a) because they are and (b) because it helps the PHP
681        maintainers who have recently made a script to detect big data structures
682        in the php code that should be moved to the .rodata section. I remembered
683        to update Builducptable as well, so it won't revert if ucptable.h is ever
684        re-created.
686     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
687        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
688        order to be able to cut out the UTF-8 tables in the latter when UTF-8
689        support is not required. This saves 1.5-2K of code, which is important in
690        some applications.
692        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
693        so as not to refer to the tables, even though these functions will never be
694        called when UTF-8 support is disabled. Otherwise there are problems with a
695        shared library.
697    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
699        (a) It was defining its arguments as char * instead of void *.
701        (b) It was assuming that all moves were upwards in memory; this was true
702            a long time ago when I wrote it, but is no longer the case.
704        The emulated memove() is provided for those environments that have neither
705        memmove() nor bcopy(). I didn't think anyone used it these days, but that
706        is clearly not the case, as these two bugs were recently reported.
708    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
709        and Detrail to create the HTML documentation, the .txt form of the man
710        pages, and it removes trailing spaces from listed files. It also creates
711        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
712        case, it wraps all the #defines with #ifndefs. This script should be run
713        before "make dist".
715    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
716        with Unicode property support.
718        (a) For a maximizing quantifier, if the two different cases of the
719            character were of different lengths in their UTF-8 codings (there are
720            some cases like this - I found 11), and the matching function had to
721            back up over a mixture of the two cases, it incorrectly assumed they
722            were both the same length.
724        (b) When PCRE was configured to use the heap rather than the stack for
725            recursion during matching, it was not correctly preserving the data for
726            the other case of a UTF-8 character when checking ahead for a match
727            while processing a minimizing repeat. If the check also involved
728            matching a wide character, but failed, corruption could cause an
729            erroneous result when trying to check for a repeat of the original
730            character.
732    13. Some tidying changes to the testing mechanism:
734        (a) The RunTest script now detects the internal link size and whether there
735            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
736            values substituted by "configure". (The RunGrepTest script already did
737            this for UTF-8.) The configure.ac script no longer substitutes the
738            relevant variables.
740        (b) The debugging options /B and /D in pcretest show the compiled bytecode
741            with length and offset values. This means that the output is different
742            for different internal link sizes. Test 2 is skipped for link sizes
743            other than 2 because of this, bypassing the problem. Unfortunately,
744            there was also a test in test 3 (the locale tests) that used /B and
745            failed for link sizes other than 2. Rather than cut the whole test out,
746            I have added a new /Z option to pcretest that replaces the length and
747            offset values with spaces. This is now used to make test 3 independent
748            of link size. (Test 2 will be tidied up later.)
750    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
751        segmentation fault instead of returning the appropriate error message.
753    15. In multiline mode when the newline sequence was set to "any", the pattern
754        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
755        This doesn't seem right; it now treats the CRLF combination as the line
756        ending, and so does not match in that case. It's only a pattern such as ^$
757        that would hit this one: something like ^ABC$ would have failed after \r
758        and then tried again after \r\n.
760    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
761        in an attempt to make files that differ only in their line terminators
762        compare equal. This works on Linux.
764    17. Under certain error circumstances pcregrep might try to free random memory
765        as it exited. This is now fixed, thanks to valgrind.
767    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
768        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
769        was because its rules for how to advance for /g after matching an empty
770        string at the end of a line did not allow for this case. They now check for
771        it specially.
773    20. pcretest is supposed to handle patterns and data of any length, by
774        extending its buffers when necessary. It was getting this wrong when the
775        buffer for a data line had to be extended.
777    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
778        CRLF as a newline sequence.
780    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
781        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
782        I have nevertheless tidied it up.
784    23. Added some casts to kill warnings from HP-UX ia64 compiler.
786    24. Added a man page for pcre-config.
789    Version 7.0 19-Dec-06
790    ---------------------
792     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
793        moving to gcc 4.1.1.
795     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
796        sys/time.h, which is documented as needed for this function. It doesn't
797        seem to matter on Linux, but it showed up on some releases of OS X.
799     3. It seems that there are systems where bytes whose values are greater than
800        127 match isprint() in the "C" locale. The "C" locale should be the
801        default when a C program starts up. In most systems, only ASCII printing
802        characters match isprint(). This difference caused the output from pcretest
803        to vary, making some of the tests fail. I have changed pcretest so that:
805        (a) When it is outputting text in the compiled version of a pattern, bytes
806            other than 32-126 are always shown as hex escapes.
808        (b) When it is outputting text that is a matched part of a subject string,
809            it does the same, unless a different locale has been set for the match
810            (using the /L modifier). In this case, it uses isprint() to decide.
812     4. Fixed a major bug that caused incorrect computation of the amount of memory
813        required for a compiled pattern when options that changed within the
814        pattern affected the logic of the preliminary scan that determines the
815        length. The relevant options are -x, and -i in UTF-8 mode. The result was
816        that the computed length was too small. The symptoms of this bug were
817        either the PCRE error "internal error: code overflow" from pcre_compile(),
818        or a glibc crash with a message such as "pcretest: free(): invalid next
819        size (fast)". Examples of patterns that provoked this bug (shown in
820        pcretest format) are:
822          /(?-x: )/x
823          /(?x)(?-x: \s*#\s*)/
824          /((?i)[\x{c0}])/8
825          /(?i:[\x{c0}])/8
827        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
828        is now done differently.
830     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
831        wrapper classes; (b) implement a new function in the C++ scanner that is
832        more efficient than the old way of doing things because it avoids levels of
833        recursion in the regex matching; (c) add a paragraph to the documentation
834        for the FullMatch() function.
836     6. The escape sequence \n was being treated as whatever was defined as
837        "newline". Not only was this contrary to the documentation, which states
838        that \n is character 10 (hex 0A), but it also went horribly wrong when
839        "newline" was defined as CRLF. This has been fixed.
841     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
842        was being set to -1 for the "end of line" case (supposedly a value that no
843        character can have). Though this value is never used (the check for end of
844        line is "zero bytes in current character"), it caused compiler complaints.
845        I've changed it to 0xffffffff.
847     8. In pcre_version.c, the version string was being built by a sequence of
848        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
849        string (as it is for production releases) called a macro with an empty
850        argument. The C standard says the result of this is undefined. The gcc
851        compiler treats it as an empty string (which was what was wanted) but it is
852        reported that Visual C gives an error. The source has been hacked around to
853        avoid this problem.
855     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
856        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
857        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
858        of them did).
860    10. Originally, pcretest opened its input and output without "b"; then I was
861        told that "b" was needed in some environments, so it was added for release
862        5.0 to both the input and output. (It makes no difference on Unix-like
863        systems.) Later I was told that it is wrong for the input on Windows. I've
864        now abstracted the modes into two macros, to make it easier to fiddle with
865        them, and removed "b" from the input mode under Windows.
867    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
869    12. Added -help and --help to pcretest as an official way of being reminded
870        of the options.
872    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
873        and pcrecpp.cc because they annoy compilers at high warning levels.
875    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
877    15. Fixed an occurrence of == in configure.ac that should have been = (shell
878        scripts are not C programs :-) and which was not noticed because it works
879        on Linux.
881    16. pcretest is supposed to handle any length of pattern and data line (as one
882        line or as a continued sequence of lines) by extending its input buffer if
883        necessary. This feature was broken for very long pattern lines, leading to
884        a string of junk being passed to pcre_compile() if the pattern was longer
885        than about 50K.
887    17. I have done a major re-factoring of the way pcre_compile() computes the
888        amount of memory needed for a compiled pattern. Previously, there was code
889        that made a preliminary scan of the pattern in order to do this. That was
890        OK when PCRE was new, but as the facilities have expanded, it has become
891        harder and harder to keep it in step with the real compile phase, and there
892        have been a number of bugs (see for example, 4 above). I have now found a
893        cunning way of running the real compile function in a "fake" mode that
894        enables it to compute how much memory it would need, while actually only
895        ever using a few hundred bytes of working memory and without too many
896        tests of the mode. This should make future maintenance and development
897        easier. A side effect of this work is that the limit of 200 on the nesting
898        depth of parentheses has been removed (though this was never a serious
899        limitation, I suspect). However, there is a downside: pcre_compile() now
900        runs more slowly than before (30% or more, depending on the pattern). I
901        hope this isn't a big issue. There is no effect on runtime performance.
903    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
904        newline (only possible for the last line of a file) and it was a
905        pattern that set a locale (followed by /Lsomething), pcretest crashed.
907    19. Added additional timing features to pcretest. (1) The -tm option now times
908        matching only, not compiling. (2) Both -t and -tm can be followed, as a
909        separate command line item, by a number that specifies the number of
910        repeats to use when timing. The default is 50000; this gives better
911        precision, but takes uncomfortably long for very large patterns.
913    20. Extended pcre_study() to be more clever in cases where a branch of a
914        subpattern has no definite first character. For example, (a*|b*)[cd] would
915        previously give no result from pcre_study(). Now it recognizes that the
916        first character must be a, b, c, or d.
918    21. There was an incorrect error "recursive call could loop indefinitely" if
919        a subpattern (or the entire pattern) that was being tested for matching an
920        empty string contained only one non-empty item after a nested subpattern.
921        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
922        incorrectly, because the \d was being skipped in the check.
924    22. The pcretest program now has a new pattern option /B and a command line
925        option -b, which is equivalent to adding /B to every pattern. This causes
926        it to show the compiled bytecode, without the additional information that
927        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
928        is the same as /B/I).
930    23. A new optimization is now able automatically to treat some sequences such
931        as a*b as a*+b. More specifically, if something simple (such as a character
932        or a simple class like \d) has an unlimited quantifier, and is followed by
933        something that cannot possibly match the quantified thing, the quantifier
934        is automatically "possessified".
936    24. A recursive reference to a subpattern whose number was greater than 39
937        went wrong under certain circumstances in UTF-8 mode. This bug could also
938        have affected the operation of pcre_study().
940    25. Realized that a little bit of performance could be had by replacing
941        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
943    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
945    27. Possessive quantifiers such as a++ were previously implemented by turning
946        them into atomic groups such as ($>a+). Now they have their own opcodes,
947        which improves performance. This includes the automatically created ones
948        from 23 above.
950    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
951        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
952        the first matched character to be a colon. This applied both to named and
953        numbered groups.
955    29. The ucpinternal.h header file was missing its idempotency #ifdef.
957    30. I was sent a "project" file called libpcre.a.dev which I understand makes
958        building PCRE on Windows easier, so I have included it in the distribution.
960    31. There is now a check in pcretest against a ridiculously large number being
961        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
962        loop, the loop is abandoned.
964    32. Forward references to subpatterns in conditions such as (?(2)...) where
965        subpattern 2 is defined later cause pcre_compile() to search forwards in
966        the pattern for the relevant set of parentheses. This search went wrong
967        when there were unescaped parentheses in a character class, parentheses
968        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
970    33. "Subroutine" calls and backreferences were previously restricted to
971        referencing subpatterns earlier in the regex. This restriction has now
972        been removed.
974    34. Added a number of extra features that are going to be in Perl 5.10. On the
975        whole, these are just syntactic alternatives for features that PCRE had
976        previously implemented using the Python syntax or my own invention. The
977        other formats are all retained for compatibility.
979        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
980            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
981            also .NET compatible.
983        (b) A recursion or subroutine call to a named group can now be defined as
984            (?&name) as well as (?P>name).
986        (c) A backreference to a named group can now be defined as \k<name> or
987            \k'name' as well as (?P=name). The new forms, as well as being in Perl
988            5.10, are also .NET compatible.
990        (d) A conditional reference to a named group can now use the syntax
991            (?(<name>) or (?('name') as well as (?(name).
993        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
994            groups (named and numbered) that are never evaluated inline, but can be
995            called as "subroutines" from elsewhere. In effect, the DEFINE condition
996            is always false. There may be only one alternative in such a group.
998        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
999            as the simple (?(R). The condition is true only if the most recent
1000            recursion is that of the given number or name. It does not search out
1001            through the entire recursion stack.
1003        (g) The escape \gN or \g{N} has been added, where N is a positive or
1004            negative number, specifying an absolute or relative reference.
1006    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1007        some "unreachable code" warnings.
1009    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1010        things, this adds five new scripts.
1012    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1013        There were also incompatibilities regarding the handling of \Q..\E inside
1014        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1015        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1017    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1018        matches an empty string, and forcibly breaks the loop. There were bugs in
1019        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1020        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1021        separate and independent bugs (that affected different cases) have been
1022        fixed.
1024    39. Refactored the code to abolish the use of different opcodes for small
1025        capturing bracket numbers. This is a tidy that I avoided doing when I
1026        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1027        The new approach is not only tidier, it makes it possible to reduce the
1028        memory needed to fix the previous bug (38).
1030    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1031        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1032        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1033        mode.
1035    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1036        report.
1038    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1039        copy construction and assignment in the C++ wrapper.
1041    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1042        couple of bugs that could have given wrong results in the "--newline=crlf"
1043        case.
1045    44. Added a number of casts and did some reorganization of signed/unsigned int
1046        variables following suggestions from Dair Grant. Also renamed the variable
1047        "this" as "item" because it is a C++ keyword.
1049    45. Arranged for dftables to add
1051          #include "pcre_internal.h"
1053        to pcre_chartables.c because without it, gcc 4.x may remove the array
1054        definition from the final binary if PCRE is built into a static library and
1055        dead code stripping is activated.
1057    46. For an unanchored pattern, if a match attempt fails at the start of a
1058        newline sequence, and the newline setting is CRLF or ANY, and the next two
1059        characters are CRLF, advance by two characters instead of one.
1062    Version 6.7 04-Jul-06
1063    ---------------------
1065     1. In order to handle tests when input lines are enormously long, pcretest has
1066        been re-factored so that it automatically extends its buffers when
1067        necessary. The code is crude, but this _is_ just a test program. The
1068        default size has been increased from 32K to 50K.
1070     2. The code in pcre_study() was using the value of the re argument before
1071        testing it for NULL. (Of course, in any sensible call of the function, it
1072        won't be NULL.)
1074     3. The memmove() emulation function in pcre_internal.h, which is used on
1075        systems that lack both memmove() and bcopy() - that is, hardly ever -
1076        was missing a "static" storage class specifier.
1078     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1079        containing an extended class (one that cannot be represented by a bitmap
1080        because it contains high-valued characters or Unicode property items, e.g.
1081        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1082        pattern, but PCRE should not loop if you do not (it no longer does).
1083        [Detail: two cases were found: (a) a repeated subpattern containing an
1084        extended class; (b) a recursive reference to a subpattern that followed a
1085        previous extended class. It wasn't skipping over the extended class
1086        correctly when UTF-8 mode was not set.]
1088     5. A negated single-character class was not being recognized as fixed-length
1089        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1090        compile error "lookbehind assertion is not fixed length".
1092     6. The RunPerlTest auxiliary script was showing an unexpected difference
1093        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1094        write a Perl script that can interpret lines of an input file either as
1095        byte characters or as UTF-8, which is what "perltest" was being required to
1096        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1097        can't do is switch easily at run time between having the "use utf8;" pragma
1098        or not. In the end, I fudged it by using the RunPerlTest script to insert
1099        "use utf8;" explicitly for the UTF-8 tests.
1101     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1102        the end of the subject string, contrary to the documentation and to what
1103        Perl does. This was true of both matching functions. Now it matches only at
1104        the start of the subject and immediately after *internal* newlines.
1106     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1107        a pointer to an int instead of a pointer to an unsigned long int. This
1108        caused problems on 64-bit systems.
1110     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1111        instance of the 'standard' template library not being so standard".
1113    10. There was no check on the number of named subpatterns nor the maximum
1114        length of a subpattern name. The product of these values is used to compute
1115        the size of the memory block for a compiled pattern. By supplying a very
1116        long subpattern name and a large number of named subpatterns, the size
1117        computation could be caused to overflow. This is now prevented by limiting
1118        the length of names to 32 characters, and the number of named subpatterns
1119        to 10,000.
1121    11. Subpatterns that are repeated with specific counts have to be replicated in
1122        the compiled pattern. The size of memory for this was computed from the
1123        length of the subpattern and the repeat count. The latter is limited to
1124        65535, but there was no limit on the former, meaning that integer overflow
1125        could in principle occur. The compiled length of a repeated subpattern is
1126        now limited to 30,000 bytes in order to prevent this.
1128    12. Added the optional facility to have named substrings with the same name.
1130    13. Added the ability to use a named substring as a condition, using the
1131        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1132        are numbers (not recommended). Forward references are permitted.
1134    14. Added forward references in named backreferences (if you see what I mean).
1136    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1137        pattern could run off the end of the subject. For example, the pattern
1138        "(?s)(.{1,5})"8 did this with the subject "ab".
1140    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1141        PCRE_CASELESS was set when matching characters that were quantified with ?
1142        or *.
1144    17. A character class other than a single negated character that had a minimum
1145        but no maximum quantifier - for example [ab]{6,} - was not handled
1146        correctly by pce_dfa_exec(). It would match only one character.
1148    18. A valid (though odd) pattern that looked like a POSIX character
1149        class but used an invalid character after [ (for example [[,abc,]]) caused
1150        pcre_compile() to give the error "Failed: internal error: code overflow" or
1151        in some cases to crash with a glibc free() error. This could even happen if
1152        the pattern terminated after [[ but there just happened to be a sequence of
1153        letters, a binary zero, and a closing ] in the memory that followed.
1155    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1156        over the years. Originally (before any Unicode support), just the bottom 8
1157        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1158        output from "man perlunicode" includes this:
1160          The regular expression compiler produces polymorphic opcodes.  That
1161          is, the pattern adapts to the data and automatically switches to
1162          the Unicode character scheme when presented with Unicode data--or
1163          instead uses a traditional byte scheme when presented with byte
1164          data.
1166        Sadly, a wide octal escape does not cause a switch, and in a string with
1167        no other multibyte characters, these octal escapes are treated as before.
1168        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1169        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1170        Unicode string.
1172        I have not perpetrated such confusion in PCRE. Up till now, it took just
1173        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1174        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1175        translate to the appropriate multibyte character.
1177    29. Applied some refactoring to reduce the number of warnings from Microsoft
1178        and Borland compilers. This has included removing the fudge introduced
1179        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1180        a warning about an unused variable.
1182    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1183        characters since release 4.0, because Perl (from release 5.004) does not.
1184        [Or at least, is documented not to: some releases seem to be in conflict
1185        with the documentation.] However, when a pattern was studied with
1186        pcre_study() and all its branches started with \s, PCRE still included VT
1187        as a possible starting character. Of course, this did no harm; it just
1188        caused an unnecessary match attempt.
1190    22. Removed a now-redundant internal flag bit that recorded the fact that case
1191        dependency changed within the pattern. This was once needed for "required
1192        byte" processing, but is no longer used. This recovers a now-scarce options
1193        bit. Also moved the least significant internal flag bit to the most-
1194        significant bit of the word, which was not previously used (hangover from
1195        the days when it was an int rather than a uint) to free up another bit for
1196        the future.
1198    23. Added support for CRLF line endings as well as CR and LF. As well as the
1199        default being selectable at build time, it can now be changed at runtime
1200        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1201        specify that it is scanning data with non-default line endings.
1203    24. Changed the definition of CXXLINK to make it agree with the definition of
1204        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1206    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1207        recursions. This makes a big different to stack usage for some patterns.
1209    26. If a subpattern containing a named recursion or subroutine reference such
1210        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1211        the space required for the compiled pattern went wrong and gave too small a
1212        value. Depending on the environment, this could lead to "Failed: internal
1213        error: code overflow at offset 49" or "glibc detected double free or
1214        corruption" errors.
1216    27. Applied patches from Google (a) to support the new newline modes and (b) to
1217        advance over multibyte UTF-8 characters in GlobalReplace.
1219    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1220        difference for some implementation of PCRE in some Windows version.
1222    29. Added some extra testing facilities to pcretest:
1224        \q<number>   in a data line sets the "match limit" value
1225        \Q<number>   in a data line sets the "match recursion limt" value
1226        -S <number>  sets the stack size, where <number> is in megabytes
1228        The -S option isn't available for Windows.
1231    Version 6.6 06-Feb-06
1232    ---------------------
1234     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1235        in pcreposix.h. I have copied the definition from pcre.h.
1237     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1238        because pcre.h is no longer a built file.
1240     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1241        not normally included in the compiled code.
1244  Version 6.5 01-Feb-06  Version 6.5 01-Feb-06
1245  ---------------------  ---------------------

Removed from v.87  
changed lines
  Added in v.356

  ViewVC Help
Powered by ViewVC 1.1.5