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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 01-May-07  Version 7.9 xx-xxx-09
5    ---------------------
6    
7    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
8        (pcretest), all targets were linked against these libraries. This included
9        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
10        libraries. This caused unwanted dependencies to be created. This problem
11        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
12        pcretest is linked with readline.
13    
14    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
15        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
16        moved outside it again, because FALSE and TRUE are already defined in AIX,
17        but BOOL is not.
18    
19    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
20        PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.
21    
22    4.  The pcregrep documentation said spaces were inserted as well as colons (or
23        hyphens) following file names and line numbers when outputting matching
24        lines. This is not true; no spaces are inserted. I have also clarified the
25        wording for the --colour (or --color) option.
26    
27    5.  In pcregrep, when --colour was used with -o, the list of matching strings
28        was not coloured; this is different to GNU grep, so I have changed it to be
29        the same.
30    
31    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
32        each matching line was coloured. Now it goes on to look for further matches
33        of any of the test patterns, which is the same behaviour as GNU grep.
34    
35    7.  A pattern that could match an empty string could cause pcregrep to loop; it
36        doesn't make sense to accept an empty string match in pcregrep, so I have
37        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38        seems to be how GNU grep behaves.
39    
40    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
41        start or after a newline", because the conditional assertion was not being
42        correctly handled. The rule now is that both the assertion and what follows
43        in the first alternative must satisfy the test.
44    
45    9.  If auto-callout was enabled in a pattern with a conditional group whose
46        condition was an assertion, PCRE could crash during matching, both with
47        pcre_exec() and pcre_dfa_exec().
48    
49    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
50        used for matching.
51    
52    11. Unicode property support in character classes was not working for
53        characters (bytes) greater than 127 when not in UTF-8 mode.
54    
55    12. Added the -M command line option to pcretest.
56    
57    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
58    
59    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
60    
61    16. Added comments and documentation about mis-use of no_arg in the C++
62        wrapper.
63    
64    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
65        from Martin Jerabek that uses macro names for all relevant character and
66        string constants.
67    
68    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
69        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
70        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
71        these, but not everybody uses configure.
72    
73    19. A conditional group that had only one branch was not being correctly
74        recognized as an item that could match an empty string. This meant that an
75        enclosing group might also not be so recognized, causing infinite looping
76        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
77        with the subject "ab", where knowledge that the repeated group can match
78        nothing is needed in order to break the loop.
79    
80    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
81        exec(), but without supplying a callout function, matching went wrong.
82    
83    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
84        leak if the size of the offset vector was greater than 30. When the vector
85        is smaller, the saved offsets during recursion go onto a local stack
86        vector, but for larger vectors malloc() is used. It was failing to free
87        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
88        error, in fact).
89    
90    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
91        heapframe that is used only when UTF-8 support is enabled. This caused no
92        problem, but was untidy.
93    
94    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
95        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
96        included within another project.
97    
98    24. Steven Van Ingelgem's patches to add more options to the CMake support,
99        slightly modified by me:
100    
101          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
102              not building pcregrep.
103    
104          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
105              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
106    
107    
108    Version 7.8 05-Sep-08
109    ---------------------
110    
111    1.  Replaced UCP searching code with optimized version as implemented for Ad
112        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
113        stage table and inline lookup instead of a function, giving speed ups of 2
114        to 5 times on some simple patterns that I tested. Permission was given to
115        distribute the MultiStage2.py script that generates the tables (it's not in
116        the tarball, but is in the Subversion repository).
117    
118    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
119        scripts.
120    
121    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
122        a group with a zero qualifier. The result of the study could be incorrect,
123        or the function might crash, depending on the pattern.
124    
125    4.  Caseless matching was not working for non-ASCII characters in back
126        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
127        It now works when Unicode Property Support is available.
128    
129    5.  In pcretest, an escape such as \x{de} in the data was always generating
130        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
131        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
132        truncation.
133    
134    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
135    
136    7.  Added two (int) casts to pcregrep when printing the difference of two
137        pointers, in case they are 64-bit values.
138    
139    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
140        test 2 if it fails.
141    
142    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
143        and a #define of that name to empty if it is not externally set. This is to
144        allow users of MSVC to set it if necessary.
145    
146    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
147        the convenience functions in the pcre_get.c source file.
148    
149    11. An option change at the start of a pattern that had top-level alternatives
150        could cause overwriting and/or a crash. This command provoked a crash in
151        some environments:
152    
153          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
154    
155        This potential security problem was recorded as CVE-2008-2371.
156    
157    12. For a pattern where the match had to start at the beginning or immediately
158        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
159        pcre_dfa_exec() could read past the end of the passed subject if there was
160        no match. To help with detecting such bugs (e.g. with valgrind), I modified
161        pcretest so that it places the subject at the end of its malloc-ed buffer.
162    
163    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
164        exec() might read past the end of the data buffer in UTF-8 mode.
165    
166    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
167        the data contained the byte 0x85 as part of a UTF-8 character within its
168        first line. This applied both to normal and DFA matching.
169    
170    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
171        /^[^d]*?$/8 failed to match "abc".
172    
173    16. Added a missing copyright notice to pcrecpp_internal.h.
174    
175    17. Make it more clear in the documentation that values returned from
176        pcre_exec() in ovector are byte offsets, not character counts.
177    
178    18. Tidied a few places to stop certain compilers from issuing warnings.
179    
180    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
181        supplied by Stefan Weber. I made a further small update for 7.8 because
182        there is a change of source arrangements: the pcre_searchfuncs.c module is
183        replaced by pcre_ucd.c.
184    
185    
186    Version 7.7 07-May-08
187    ---------------------
188    
189    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
190        a string to a long long, pretend we don't even have a long long." This is
191        done by checking for the strtoq, strtoll, and _strtoi64 functions.
192    
193    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
194        pre-7.6 versions, which defined a global no_arg variable instead of putting
195        it in the RE class. (See also #8 below.)
196    
197    3.  Remove a line of dead code, identified by coverity and reported by Nuno
198        Lopes.
199    
200    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
201    
202        (1) The include/exclude patterns were being applied to the whole pathnames
203            of files, instead of just to the final components.
204    
205        (2) If there was more than one level of directory, the subdirectories were
206            skipped unless they satisfied the include/exclude conditions. This is
207            inconsistent with GNU grep (and could even be seen as contrary to the
208            pcregrep specification - which I improved to make it absolutely clear).
209            The action now is always to scan all levels of directory, and just
210            apply the include/exclude patterns to regular files.
211    
212    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
213        --exclude_dir in the tests to avoid scanning .svn directories.
214    
215    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
216        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
217        doesn't support NULs in patterns.
218    
219    7.  Added some missing "const"s to declarations of static tables in
220        pcre_compile.c and pcre_dfa_exec.c.
221    
222    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
223        caused by fix #2  above. (Subsequently also a second patch to fix the
224        first patch. And a third patch - this was a messy problem.)
225    
226    9.  Applied Craig's patch to remove the use of push_back().
227    
228    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
229        matching function regexec().
230    
231    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
232        which, however, unlike Perl's \g{...}, are subroutine calls, not back
233        references. PCRE supports relative numbers with this syntax (I don't think
234        Oniguruma does).
235    
236    12. Previously, a group with a zero repeat such as (...){0} was completely
237        omitted from the compiled regex. However, this means that if the group
238        was called as a subroutine from elsewhere in the pattern, things went wrong
239        (an internal error was given). Such groups are now left in the compiled
240        pattern, with a new opcode that causes them to be skipped at execution
241        time.
242    
243    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
244        to the way PCRE behaves:
245    
246        (a) A lone ] character is dis-allowed (Perl treats it as data).
247    
248        (b) A back reference to an unmatched subpattern matches an empty string
249            (Perl fails the current match path).
250    
251        (c) A data ] in a character class must be notated as \] because if the
252            first data character in a class is ], it defines an empty class. (In
253            Perl it is not possible to have an empty class.) The empty class []
254            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
255            The negative empty class [^] matches any one character, independently
256            of the DOTALL setting.
257    
258    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
259        non-existent subpattern following a character class starting with ']' and
260        containing () gave an internal compiling error instead of "reference to
261        non-existent subpattern". Fortunately, when the pattern did exist, the
262        compiled code was correct. (When scanning forwards to check for the
263        existencd of the subpattern, it was treating the data ']' as terminating
264        the class, so got the count wrong. When actually compiling, the reference
265        was subsequently set up correctly.)
266    
267    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
268        it was being rejected as not supported by pcre_dfa_exec(), even though
269        other assertions are supported. I have made pcre_dfa_exec() support
270        (*FAIL).
271    
272    16. The implementation of 13c above involved the invention of a new opcode,
273        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
274        cannot be changed at match time, I realized I could make a small
275        improvement to matching performance by compiling OP_ALLANY instead of
276        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
277        on the OP_ANY path.
278    
279    17. Compiling pcretest on Windows with readline support failed without the
280        following two fixes: (1) Make the unistd.h include conditional on
281        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
282    
283    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
284        ncurses library to be included for pcretest when ReadLine support is
285        requested, but also to allow for it to be overridden. This patch came from
286        Daniel Bergström.
287    
288    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
289        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
290        any errors with the current Unicode tables. Thanks to Peter Kankowski for
291        spotting this.
292    
293    
294    Version 7.6 28-Jan-08
295    ---------------------
296    
297    1.  A character class containing a very large number of characters with
298        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
299        overflow.
300    
301    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
302        HAVE_LONG_LONG is not defined.
303    
304    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
305        bring them up to date and include new features. This patch includes:
306    
307        - Fixed PH's badly added libz and libbz2 support.
308        - Fixed a problem with static linking.
309        - Added pcredemo. [But later removed - see 7 below.]
310        - Fixed dftables problem and added an option.
311        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
312            HAVE_LONG_LONG.
313        - Added readline support for pcretest.
314        - Added an listing of the option settings after cmake has run.
315    
316    4.  A user submitted a patch to Makefile that makes it easy to create
317        "pcre.dll" under mingw when using Configure/Make. I added stuff to
318        Makefile.am that cause it to include this special target, without
319        affecting anything else. Note that the same mingw target plus all
320        the other distribution libraries and programs are now supported
321        when configuring with CMake (see 6 below) instead of with
322        Configure/Make.
323    
324    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
325        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
326        exported in the Windows port". It has not yet been confirmed that the patch
327        solves the problem, but it does no harm.
328    
329    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
330        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
331        with CMake, and also correct the comment about stack recursion.
332    
333    7.  Remove the automatic building of pcredemo from the ./configure system and
334        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
335        of a program that users should build themselves after PCRE is installed, so
336        building it automatically is not really right. What is more, it gave
337        trouble in some build environments.
338    
339    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
340    
341    
342    Version 7.5 10-Jan-08
343    ---------------------
344    
345    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
346        values in parens when parsing an RE using the C++ wrapper."
347    
348    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
349        Characters greater than 255 were excluded from the class instead of being
350        included.
351    
352    3.  The same bug as (2) above applied to negated POSIX classes such as
353        [:^space:].
354    
355    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
356        defined or documented. It seems to have been a typo for PCRE_STATIC, so
357        I have changed it.
358    
359    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
360        first named subpattern) and a construct such as (?&a) would reference the
361        first named subpattern whose name started with "a" (in other words, the
362        length check was missing). Both these problems are fixed. "Subpattern name
363        expected" is now given for (?&) (a zero-length name), and this patch also
364        makes it give the same error for \k'' (previously it complained that that
365        was a reference to a non-existent subpattern).
366    
367    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
368        this is right because (?- can be followed by option settings as well as by
369        digits. I have, however, made the messages clearer.
370    
371    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
372        than the number used in the conditional) now cause a compile-time error.
373        This is actually not compatible with Perl, which accepts such patterns, but
374        treats the conditional as always being FALSE (as PCRE used to), but it
375        seems to me that giving a diagnostic is better.
376    
377    8.  Change "alphameric" to the more common word "alphanumeric" in comments
378        and messages.
379    
380    9.  Fix two occurrences of "backslash" in comments that should have been
381        "backspace".
382    
383    10. Remove two redundant lines of code that can never be obeyed (their function
384        was moved elsewhere).
385    
386    11. The program that makes PCRE's Unicode character property table had a bug
387        which caused it to generate incorrect table entries for sequences of
388        characters that have the same character type, but are in different scripts.
389        It amalgamated them into a single range, with the script of the first of
390        them. In other words, some characters were in the wrong script. There were
391        thirteen such cases, affecting characters in the following ranges:
392    
393          U+002b0 - U+002c1
394          U+0060c - U+0060d
395          U+0061e - U+00612
396          U+0064b - U+0065e
397          U+0074d - U+0076d
398          U+01800 - U+01805
399          U+01d00 - U+01d77
400          U+01d9b - U+01dbf
401          U+0200b - U+0200f
402          U+030fc - U+030fe
403          U+03260 - U+0327f
404          U+0fb46 - U+0fbb1
405          U+10450 - U+1049d
406    
407    12. The -o option (show only the matching part of a line) for pcregrep was not
408        compatible with GNU grep in that, if there was more than one match in a
409        line, it showed only the first of them. It now behaves in the same way as
410        GNU grep.
411    
412    13. If the -o and -v options were combined for pcregrep, it printed a blank
413        line for every non-matching line. GNU grep prints nothing, and pcregrep now
414        does the same. The return code can be used to tell if there were any
415        non-matching lines.
416    
417    14. Added --file-offsets and --line-offsets to pcregrep.
418    
419    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
420        infinitely looping recursion. The bug was that positive lookaheads were not
421        being skipped when checking for a possible empty match (negative lookaheads
422        and both kinds of lookbehind were skipped).
423    
424    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
425        inclusion of <windows.h> to before rather than after the definition of
426        INVALID_FILE_ATTRIBUTES (patch from David Byron).
427    
428    17. Specifying a possessive quantifier with a specific limit for a Unicode
429        character property caused pcre_compile() to compile bad code, which led at
430        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
431        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
432        caused the error; without that there was no problem.
433    
434    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
435    
436    19. Added --enable-pcretest-libreadline.
437    
438    20. In pcrecpp.cc, the variable 'count' was incremented twice in
439        RE::GlobalReplace(). As a result, the number of replacements returned was
440        double what it should be. I removed one of the increments, but Craig sent a
441        later patch that removed the other one (the right fix) and added unit tests
442        that check the return values (which was not done before).
443    
444    21. Several CMake things:
445    
446        (1) Arranged that, when cmake is used on Unix, the libraries end up with
447            the names libpcre and libpcreposix, not just pcre and pcreposix.
448    
449        (2) The above change means that pcretest and pcregrep are now correctly
450            linked with the newly-built libraries, not previously installed ones.
451    
452        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
453    
454    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
455        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
456        UTF-8 newline character). The key issue is that the pattern starts .*;
457        this means that the match must be either at the beginning, or after a
458        newline. The bug was in the code for advancing after a failed match and
459        checking that the new position followed a newline. It was not taking
460        account of UTF-8 characters correctly.
461    
462    23. PCRE was behaving differently from Perl in the way it recognized POSIX
463        character classes. PCRE was not treating the sequence [:...:] as a
464        character class unless the ... were all letters. Perl, however, seems to
465        allow any characters between [: and :], though of course it rejects as
466        unknown any "names" that contain non-letters, because all the known class
467        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
468        for example, whereas PCRE did not - it did not recognize a POSIX character
469        class. This seemed a bit dangerous, so the code has been changed to be
470        closer to Perl. The behaviour is not identical to Perl, because PCRE will
471        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
472        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
473        Perl does, and where it didn't before.
474    
475    24. Rewrite so as to remove the single use of %n from pcregrep because in some
476        Windows environments %n is disabled by default.
477    
478    
479    Version 7.4 21-Sep-07
480    ---------------------
481    
482    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
483        means that a class such as [\s] counted as "explicit reference to CR or
484        LF". That isn't really right - the whole point of the change was to try to
485        help when there was an actual mention of one of the two characters. So now
486        the change happens only if \r or \n (or a literal CR or LF) character is
487        encountered.
488    
489    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
490        of both had grown to the point where there were only 3 bits left.
491        Fortunately, there was spare space in the data structure, and so I have
492        moved the internal flags into a new 16-bit field to free up more option
493        bits.
494    
495    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
496        but did not set the internal JCHANGED flag - either of these is enough to
497        control the way the "get" function works - but the PCRE_INFO_JCHANGED
498        facility is supposed to tell if (?J) was ever used, so now (?J) at the
499        start sets both bits.
500    
501    4.  Added options (at build time, compile time, exec time) to change \R from
502        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
503    
504    5.  doc/pcresyntax.html was missing from the distribution.
505    
506    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
507        compatibility, even though it is no longer used.
508    
509    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
510        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
511        windows.h file is present (where different names are used). [This was
512        reversed later after testing - see 16 below.]
513    
514    8.  Changed all #include <config.h> to #include "config.h". There were also
515        some further <pcre.h> cases that I changed to "pcre.h".
516    
517    9.  When pcregrep was used with the --colour option, it missed the line ending
518        sequence off the lines that it output.
519    
520    10. It was pointed out to me that arrays of string pointers cause lots of
521        relocations when a shared library is dynamically loaded. A technique of
522        using a single long string with a table of offsets can drastically reduce
523        these. I have refactored PCRE in four places to do this. The result is
524        dramatic:
525    
526          Originally:                          290
527          After changing UCP table:            187
528          After changing error message table:   43
529          After changing table of "verbs"       36
530          After changing table of Posix names   22
531    
532        Thanks to the folks working on Gregex for glib for this insight.
533    
534    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
535        unicode-properties was also set.
536    
537    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
538    
539    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
540        checked only for CRLF.
541    
542    14. Added casts to pcretest.c to avoid compiler warnings.
543    
544    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
545    
546    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
547        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
548        entirely. This removes changes made in 7 above.
549    
550    17. The CMake files have been updated, and there is now more information about
551        building with CMake in the NON-UNIX-USE document.
552    
553    
554    Version 7.3 28-Aug-07
555    ---------------------
556    
557     1. In the rejigging of the build system that eventually resulted in 7.1, the
558        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
559        brackets there is not right, since it causes compilers to look for an
560        installed pcre.h, not the version that is in the source that is being
561        compiled (which of course may be different). I have changed it back to:
562    
563          #include "pcre.h"
564    
565        I have a vague recollection that the change was concerned with compiling in
566        different directories, but in the new build system, that is taken care of
567        by the VPATH setting the Makefile.
568    
569     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
570        when the subject happened to end in the byte 0x85 (e.g. if the last
571        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
572        characters but of course it shouldn't be taken as a newline when it is part
573        of another character. The bug was that, for an unlimited repeat of . in
574        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
575        characters when looking for a newline.
576    
577     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
578    
579     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
580        in debug output.
581    
582     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
583        long printing in the pcrecpp unittest when running under MinGW.
584    
585     6. ESC_K was left out of the EBCDIC table.
586    
587     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
588        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
589        limit also applies to "virtual nesting" when a pattern is recursive, and in
590        this case 1000 isn't so big. I have been able to remove this limit at the
591        expense of backing off one optimization in certain circumstances. Normally,
592        when pcre_exec() would call its internal match() function recursively and
593        immediately return the result unconditionally, it uses a "tail recursion"
594        feature to save stack. However, when a subpattern that can match an empty
595        string has an unlimited repetition quantifier, it no longer makes this
596        optimization. That gives it a stack frame in which to save the data for
597        checking that an empty string has been matched. Previously this was taken
598        from the 1000-entry workspace that had been reserved. So now there is no
599        explicit limit, but more stack is used.
600    
601     8. Applied Daniel's patches to solve problems with the import/export magic
602        syntax that is required for Windows, and which was going wrong for the
603        pcreposix and pcrecpp parts of the library. These were overlooked when this
604        problem was solved for the main library.
605    
606     9. There were some crude static tests to avoid integer overflow when computing
607        the size of patterns that contain repeated groups with explicit upper
608        limits. As the maximum quantifier is 65535, the maximum group length was
609        set at 30,000 so that the product of these two numbers did not overflow a
610        32-bit integer. However, it turns out that people want to use groups that
611        are longer than 30,000 bytes (though not repeat them that many times).
612        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
613        made it possible to implement the integer overflow checks in a much more
614        dynamic way, which I have now done. The artificial limitation on group
615        length has been removed - we now have only the limit on the total length of
616        the compiled pattern, which depends on the LINK_SIZE setting.
617    
618    10. Fixed a bug in the documentation for get/copy named substring when
619        duplicate names are permitted. If none of the named substrings are set, the
620        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
621        empty string.
622    
623    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
624        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
625        because the ] is interpreted as the first data character and the
626        terminating ] is not found. PCRE has been made compatible with Perl in this
627        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
628        cause memory overwriting.
629    
630    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
631        string has been matched (to stop an infinite loop). It was not recognizing
632        a conditional subpattern that could match an empty string if that
633        subpattern was within another subpattern. For example, it looped when
634        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
635        condition was not nested. This bug has been fixed.
636    
637    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
638        past the start of the subject in the presence of bytes with the top bit
639        set, for example "\x8aBCD".
640    
641    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
642        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
643    
644    14. Optimized (?!) to (*FAIL).
645    
646    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
647        This restricts code points to be within the range 0 to 0x10FFFF, excluding
648        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
649        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
650        does: it's just the validity check that is more restrictive.
651    
652    16. Inserted checks for integer overflows during escape sequence (backslash)
653        processing, and also fixed erroneous offset values for syntax errors during
654        backslash processing.
655    
656    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
657        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
658    
659    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
660        caused an overrun.
661    
662    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
663        something other than just ASCII characters) inside a group that had an
664        unlimited repeat caused a loop at compile time (while checking to see
665        whether the group could match an empty string).
666    
667    20. Debugging a pattern containing \p or \P could cause a crash. For example,
668        [\P{Any}] did so. (Error in the code for printing property names.)
669    
670    21. An orphan \E inside a character class could cause a crash.
671    
672    22. A repeated capturing bracket such as (A)? could cause a wild memory
673        reference during compilation.
674    
675    23. There are several functions in pcre_compile() that scan along a compiled
676        expression for various reasons (e.g. to see if it's fixed length for look
677        behind). There were bugs in these functions when a repeated \p or \P was
678        present in the pattern. These operators have additional parameters compared
679        with \d, etc, and these were not being taken into account when moving along
680        the compiled data. Specifically:
681    
682        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
683            length.
684    
685        (b) An item such as \pL+ within a repeated group could cause crashes or
686            loops.
687    
688        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
689            "reference to non-existent subpattern" error.
690    
691        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
692    
693    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
694        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
695    
696    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
697    
698    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
699        character were causing crashes (broken optimization).
700    
701    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
702        \p or \P) caused a compile-time loop.
703    
704    28. More problems have arisen in unanchored patterns when CRLF is a valid line
705        break. For example, the unstudied pattern [\r\n]A does not match the string
706        "\r\nA" because change 7.0/46 below moves the current point on by two
707        characters after failing to match at the start. However, the pattern \nA
708        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
709        the same is true. There doesn't seem any very clean way out of this, but
710        what I have chosen to do makes the common cases work: PCRE now takes note
711        of whether there can be an explicit match for \r or \n anywhere in the
712        pattern, and if so, 7.0/46 no longer applies. As part of this change,
713        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
714        pattern has explicit CR or LF references.
715    
716    29. Added (*CR) etc for changing newline setting at start of pattern.
717    
718    
719    Version 7.2 19-Jun-07
720  ---------------------  ---------------------
721    
722   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 9  Version 7.2 01-May-07 Line 724  Version 7.2 01-May-07
724    
725   2. Re-jig the pcregrep tests with different newline settings in an attempt   2. Re-jig the pcregrep tests with different newline settings in an attempt
726      to make them independent of the local environment's newline setting.      to make them independent of the local environment's newline setting.
727    
728   3. Add code to configure.ac to remove -g from the CFLAGS default settings.   3. Add code to configure.ac to remove -g from the CFLAGS default settings.
729    
730     4. Some of the "internals" tests were previously cut out when the link size
731        was not 2, because the output contained actual offsets. The recent new
732        "Z" feature of pcretest means that these can be cut out, making the tests
733        usable with all link sizes.
734    
735     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
736        stack recursion. This gives a massive performance boost under BSD, but just
737        a small improvement under Linux. However, it saves one field in the frame
738        in all cases.
739    
740     6. Added more features from the forthcoming Perl 5.10:
741    
742        (a) (?-n) (where n is a string of digits) is a relative subroutine or
743            recursion call. It refers to the nth most recently opened parentheses.
744    
745        (b) (?+n) is also a relative subroutine call; it refers to the nth next
746            to be opened parentheses.
747    
748        (c) Conditions that refer to capturing parentheses can be specified
749            relatively, for example, (?(-2)... or (?(+3)...
750    
751        (d) \K resets the start of the current match so that everything before
752            is not part of it.
753    
754        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
755    
756        (f) \g{name} is another synonym - part of Perl 5.10's unification of
757            reference syntax.
758    
759        (g) (?| introduces a group in which the numbering of parentheses in each
760            alternative starts with the same number.
761    
762        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
763    
764     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
765        PCRE_INFO_JCHANGED.
766    
767     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
768        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
769        for detecting groups that can match an empty string.
770    
771     9. A pattern with a very large number of alternatives (more than several
772        hundred) was running out of internal workspace during the pre-compile
773        phase, where pcre_compile() figures out how much memory will be needed. A
774        bit of new cunning has reduced the workspace needed for groups with
775        alternatives. The 1000-alternative test pattern now uses 12 bytes of
776        workspace instead of running out of the 4096 that are available.
777    
778    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
779    
780    11. Applied patch from Google to remove an optimization that didn't quite work.
781        The report of the bug said:
782    
783          pcrecpp::RE("a*").FullMatch("aaa") matches, while
784          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
785          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
786    
787    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
788        it matched the wrong number of bytes.
789    
790    
791  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

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