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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.02 01-Mar-2010
5    ------------------------
6    
7    1.  The Unicode data tables have been updated to Unicode 5.2.0.
8    
9    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10        configured.
11    
12    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
13        original author of that file, following a query about its status.
14    
15    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
16        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
17    
18    
19    Version 8.01 19-Jan-2010
20    ------------------------
21    
22    1.  If a pattern contained a conditional subpattern with only one branch (in
23        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
24        computed the wrong minimum data length (which is of course zero for such
25        subpatterns). This could cause incorrect "no match" results.
26    
27    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
28        the pattern is reset in the first branch, pcre_compile() failed with
29        "internal error: code overflow at offset...". This happened only when
30        the reset was to the original external option setting. (An optimization
31        abstracts leading options settings into an external setting, which was the
32        cause of this.)
33    
34    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
35        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
36        assertion pattern did not match (meaning that the assertion was true), it
37        was incorrectly treated as false if the SKIP had been reached during the
38        matching. This also applied to assertions used as conditions.
39    
40    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
41        assertion subpattern, including such a pattern used as a condition,
42        unpredictable results occurred, instead of the error return
43        PCRE_ERROR_DFA_UITEM.
44    
45    5.  The C++ GlobalReplace function was not working like Perl for the special
46        situation when an empty string is matched. It now does the fancy magic
47        stuff that is necessary.
48    
49    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
50        removed. (These were left over from very, very early versions of PCRE.)
51    
52    7.  Some cosmetic changes to the code to make life easier when compiling it
53        as part of something else:
54    
55        (a) Change DEBUG to PCRE_DEBUG.
56    
57        (b) In pcre_compile(), rename the member of the "branch_chain" structure
58            called "current" as "current_branch", to prevent a collision with the
59            Linux macro when compiled as a kernel module.
60    
61        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
62            prevent a collision with the Linux macro when compiled as a kernel
63            module.
64    
65    8.  In pcre_compile() there are some checks for integer overflows that used to
66        cast potentially large values to (double). This has been changed to that
67        when building, a check for int64_t is made, and if it is found, it is used
68        instead, thus avoiding the use of floating point arithmetic. (There is no
69        other use of FP in PCRE.) If int64_t is not found, the fallback is to
70        double.
71    
72    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
73        2005 (difference between two addresses compared to an unsigned value).
74    
75    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
76        custom one, because of the following reported problem in Windows:
77    
78          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
79              under Win32.
80          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
81              therefore missing the function definition.
82          - The compiler thus generates a "C" signature for the test function.
83          - The linker fails to find the "C" function.
84          - PCRE fails to configure if asked to do so against libbz2.
85    
86    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
87        messages were output:
88    
89          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
90          rerunning libtoolize, to keep the correct libtool macros in-tree.
91          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
92    
93        I have done both of these things.
94    
95    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
96        most of the time, it *can* run out if it is given a pattern that contains a
97        runaway infinite recursion. I updated the discussion in the pcrestack man
98        page.
99    
100    13. Now that we have gone to the x.xx style of version numbers, the minor
101        version may start with zero. Using 08 or 09 is a bad idea because users
102        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
103        interpreted as invalid octal numbers. I've updated the previous comment in
104        configure.ac, and also added a check that gives an error if 08 or 09 are
105        used.
106    
107    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
108        causing partial matching to fail when the end of the subject matched \W
109        in a UTF-8 pattern where \W was quantified with a minimum of 3.
110    
111    15. There were some discrepancies between the declarations in pcre_internal.h
112        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
113        their definitions. The declarations used "const uschar *" and the
114        definitions used USPTR. Even though USPTR is normally defined as "const
115        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
116        reported that: "This difference in casting confuses some C++ compilers, for
117        example, SunCC recognizes above declarations as different functions and
118        generates broken code for hbpcre." I have changed the declarations to use
119        USPTR.
120    
121    16. GNU libtool is named differently on some systems. The autogen.sh script now
122        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
123        (FreeBSD).
124    
125    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
126        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
127        comment: "Figure out how to create a longlong from a string: strtoll and
128        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
129        instance, but it only takes 2 args instead of 3!"
130    
131    18. A subtle bug concerned with back references has been fixed by a change of
132        specification, with a corresponding code fix. A pattern such as
133        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
134        refers, was giving matches when it shouldn't. For example, xa=xaaa would
135        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
136        same bug. Such groups have to be quantified to be useful, or contained
137        inside another quantified group. (If there's no repetition, the reference
138        can never match.) The problem arises because, having left the group and
139        moved on to the rest of the pattern, a later failure that backtracks into
140        the group uses the captured value from the final iteration of the group
141        rather than the correct earlier one. I have fixed this in PCRE by forcing
142        any group that contains a reference to itself to be an atomic group; that
143        is, there cannot be any backtracking into it once it has completed. This is
144        similar to recursive and subroutine calls.
145    
146    
147    Version 8.00 19-Oct-09
148    ----------------------
149    
150    1.  The table for translating pcre_compile() error codes into POSIX error codes
151        was out-of-date, and there was no check on the pcre_compile() error code
152        being within the table. This could lead to an OK return being given in
153        error.
154    
155    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
156        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
157        in a Windows environment.
158    
159    3.  The pcregrep --count option prints the count for each file even when it is
160        zero, as does GNU grep. However, pcregrep was also printing all files when
161        --files-with-matches was added. Now, when both options are given, it prints
162        counts only for those files that have at least one match. (GNU grep just
163        prints the file name in this circumstance, but including the count seems
164        more useful - otherwise, why use --count?) Also ensured that the
165        combination -clh just lists non-zero counts, with no names.
166    
167    4.  The long form of the pcregrep -F option was incorrectly implemented as
168        --fixed_strings instead of --fixed-strings. This is an incompatible change,
169        but it seems right to fix it, and I didn't think it was worth preserving
170        the old behaviour.
171    
172    5.  The command line items --regex=pattern and --regexp=pattern were not
173        recognized by pcregrep, which required --regex pattern or --regexp pattern
174        (with a space rather than an '='). The man page documented the '=' forms,
175        which are compatible with GNU grep; these now work.
176    
177    6.  No libpcreposix.pc file was created for pkg-config; there was just
178        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
179    
180    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
181        when UCP support is not needed, by modifying the Python script that
182        generates it from Unicode data files. This should not matter if the module
183        is correctly used as a library, but I received one complaint about 50K of
184        unwanted data. My guess is that the person linked everything into his
185        program rather than using a library. Anyway, it does no harm.
186    
187    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
188        was a minimum greater than 1 for a wide character in a possessive
189        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
190        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
191        character. Chaos in the form of incorrect output or a compiling loop could
192        result.
193    
194    9.  The restrictions on what a pattern can contain when partial matching is
195        requested for pcre_exec() have been removed. All patterns can now be
196        partially matched by this function. In addition, if there are at least two
197        slots in the offset vector, the offset of the earliest inspected character
198        for the match and the offset of the end of the subject are set in them when
199        PCRE_ERROR_PARTIAL is returned.
200    
201    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
202        synonymous with PCRE_PARTIAL, for backwards compatibility, and
203        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
204        and may be more useful for multi-segment matching.
205    
206    11. Partial matching with pcre_exec() is now more intuitive. A partial match
207        used to be given if ever the end of the subject was reached; now it is
208        given only if matching could not proceed because another character was
209        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
210        string "Z", which now yields "no match" instead of "partial match". In the
211        case of pcre_dfa_exec(), "no match" is given if every matching path for the
212        final character ended with (*FAIL).
213    
214    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
215        if the pattern had a "must contain" character that was already found in the
216        earlier partial match, unless partial matching was again requested. For
217        example, with the pattern /dog.(body)?/, the "must contain" character is
218        "g". If the first part-match was for the string "dog", restarting with
219        "sbody" failed. This bug has been fixed.
220    
221    13. The string returned by pcre_dfa_exec() after a partial match has been
222        changed so that it starts at the first inspected character rather than the
223        first character of the match. This makes a difference only if the pattern
224        starts with a lookbehind assertion or \b or \B (\K is not supported by
225        pcre_dfa_exec()). It's an incompatible change, but it makes the two
226        matching functions compatible, and I think it's the right thing to do.
227    
228    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
229        so that the demonstration program is easily available in environments where
230        PCRE has not been installed from source.
231    
232    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
233        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
234        library.
235    
236    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
237        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
238        is not the first non-POSIX option to be added. Clearly some people find
239        these options useful.
240    
241    17. If a caller to the POSIX matching function regexec() passes a non-zero
242        value for nmatch with a NULL value for pmatch, the value of
243        nmatch is forced to zero.
244    
245    18. RunGrepTest did not have a test for the availability of the -u option of
246        the diff command, as RunTest does. It now checks in the same way as
247        RunTest, and also checks for the -b option.
248    
249    19. If an odd number of negated classes containing just a single character
250        interposed, within parentheses, between a forward reference to a named
251        subpattern and the definition of the subpattern, compilation crashed with
252        an internal error, complaining that it could not find the referenced
253        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
254        [The bug was that it was starting one character too far in when skipping
255        over the character class, thus treating the ] as data rather than
256        terminating the class. This meant it could skip too much.]
257    
258    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
259        /g option in pcretest when the pattern contains \K, which makes it possible
260        to have an empty string match not at the start, even when the pattern is
261        anchored. Updated pcretest and pcredemo to use this option.
262    
263    21. If the maximum number of capturing subpatterns in a recursion was greater
264        than the maximum at the outer level, the higher number was returned, but
265        with unset values at the outer level. The correct (outer level) value is
266        now given.
267    
268    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
269        PCRE did not set those parentheses (unlike Perl). I have now found a way to
270        make it do so. The string so far is captured, making this feature
271        compatible with Perl.
272    
273    23. The tests have been re-organized, adding tests 11 and 12, to make it
274        possible to check the Perl 5.10 features against Perl 5.10.
275    
276    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
277        pattern matches a fixed length string. PCRE did not allow this; now it
278        does. Neither allows recursion.
279    
280    25. I finally figured out how to implement a request to provide the minimum
281        length of subject string that was needed in order to match a given pattern.
282        (It was back references and recursion that I had previously got hung up
283        on.) This code has now been added to pcre_study(); it finds a lower bound
284        to the length of subject needed. It is not necessarily the greatest lower
285        bound, but using it to avoid searching strings that are too short does give
286        some useful speed-ups. The value is available to calling programs via
287        pcre_fullinfo().
288    
289    26. While implementing 25, I discovered to my embarrassment that pcretest had
290        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
291        study optimizations had never been tested with that matching function.
292        Oops. What is worse, even when it was passed study data, there was a bug in
293        pcre_dfa_exec() that meant it never actually used it. Double oops. There
294        were also very few tests of studied patterns with pcre_dfa_exec().
295    
296    27. If (?| is used to create subpatterns with duplicate numbers, they are now
297        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
298        on the other side of the coin, they are no longer allowed to have different
299        names, because these cannot be distinguished in PCRE, and this has caused
300        confusion. (This is a difference from Perl.)
301    
302    28. When duplicate subpattern names are present (necessarily with different
303        numbers, as required by 27 above), and a test is made by name in a
304        conditional pattern, either for a subpattern having been matched, or for
305        recursion in such a pattern, all the associated numbered subpatterns are
306        tested, and the overall condition is true if the condition is true for any
307        one of them. This is the way Perl works, and is also more like the way
308        testing by number works.
309    
310    
311    Version 7.9 11-Apr-09
312    ---------------------
313    
314    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
315        (pcretest), all targets were linked against these libraries. This included
316        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
317        libraries. This caused unwanted dependencies to be created. This problem
318        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
319        pcretest is linked with readline.
320    
321    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
322        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
323        moved outside it again, because FALSE and TRUE are already defined in AIX,
324        but BOOL is not.
325    
326    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
327        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
328    
329    4.  The pcregrep documentation said spaces were inserted as well as colons (or
330        hyphens) following file names and line numbers when outputting matching
331        lines. This is not true; no spaces are inserted. I have also clarified the
332        wording for the --colour (or --color) option.
333    
334    5.  In pcregrep, when --colour was used with -o, the list of matching strings
335        was not coloured; this is different to GNU grep, so I have changed it to be
336        the same.
337    
338    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
339        each matching line was coloured. Now it goes on to look for further matches
340        of any of the test patterns, which is the same behaviour as GNU grep.
341    
342    7.  A pattern that could match an empty string could cause pcregrep to loop; it
343        doesn't make sense to accept an empty string match in pcregrep, so I have
344        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
345        seems to be how GNU grep behaves.
346    
347    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
348        start or after a newline", because the conditional assertion was not being
349        correctly handled. The rule now is that both the assertion and what follows
350        in the first alternative must satisfy the test.
351    
352    9.  If auto-callout was enabled in a pattern with a conditional group whose
353        condition was an assertion, PCRE could crash during matching, both with
354        pcre_exec() and pcre_dfa_exec().
355    
356    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
357        used for matching.
358    
359    11. Unicode property support in character classes was not working for
360        characters (bytes) greater than 127 when not in UTF-8 mode.
361    
362    12. Added the -M command line option to pcretest.
363    
364    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
365    
366    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
367    
368    16. Added comments and documentation about mis-use of no_arg in the C++
369        wrapper.
370    
371    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
372        from Martin Jerabek that uses macro names for all relevant character and
373        string constants.
374    
375    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
376        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
377        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
378        these, but not everybody uses configure.
379    
380    19. A conditional group that had only one branch was not being correctly
381        recognized as an item that could match an empty string. This meant that an
382        enclosing group might also not be so recognized, causing infinite looping
383        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
384        with the subject "ab", where knowledge that the repeated group can match
385        nothing is needed in order to break the loop.
386    
387    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
388        exec(), but without supplying a callout function, matching went wrong.
389    
390    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
391        leak if the size of the offset vector was greater than 30. When the vector
392        is smaller, the saved offsets during recursion go onto a local stack
393        vector, but for larger vectors malloc() is used. It was failing to free
394        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
395        error, in fact).
396    
397    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
398        heapframe that is used only when UTF-8 support is enabled. This caused no
399        problem, but was untidy.
400    
401    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
402        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
403        included within another project.
404    
405    24. Steven Van Ingelgem's patches to add more options to the CMake support,
406        slightly modified by me:
407    
408          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
409              not building pcregrep.
410    
411          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
412              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
413    
414    25. Forward references, both numeric and by name, in patterns that made use of
415        duplicate group numbers, could behave incorrectly or give incorrect errors,
416        because when scanning forward to find the reference group, PCRE was not
417        taking into account the duplicate group numbers. A pattern such as
418        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
419    
420    26. Changed a few more instances of "const unsigned char *" to USPTR, making
421        the feature of a custom pointer more persuasive (as requested by a user).
422    
423    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
424        pcretest.c, inside #ifndefs, because it seems they are sometimes already
425        pre-defined.
426    
427    28. Added support for (*UTF8) at the start of a pattern.
428    
429    29. Arrange for flags added by the "release type" setting in CMake to be shown
430        in the configuration summary.
431    
432    
433    Version 7.8 05-Sep-08
434    ---------------------
435    
436    1.  Replaced UCP searching code with optimized version as implemented for Ad
437        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
438        stage table and inline lookup instead of a function, giving speed ups of 2
439        to 5 times on some simple patterns that I tested. Permission was given to
440        distribute the MultiStage2.py script that generates the tables (it's not in
441        the tarball, but is in the Subversion repository).
442    
443    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
444        scripts.
445    
446    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
447        a group with a zero qualifier. The result of the study could be incorrect,
448        or the function might crash, depending on the pattern.
449    
450    4.  Caseless matching was not working for non-ASCII characters in back
451        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
452        It now works when Unicode Property Support is available.
453    
454    5.  In pcretest, an escape such as \x{de} in the data was always generating
455        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
456        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
457        truncation.
458    
459    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
460    
461    7.  Added two (int) casts to pcregrep when printing the difference of two
462        pointers, in case they are 64-bit values.
463    
464    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
465        test 2 if it fails.
466    
467    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
468        and a #define of that name to empty if it is not externally set. This is to
469        allow users of MSVC to set it if necessary.
470    
471    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
472        the convenience functions in the pcre_get.c source file.
473    
474    11. An option change at the start of a pattern that had top-level alternatives
475        could cause overwriting and/or a crash. This command provoked a crash in
476        some environments:
477    
478          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
479    
480        This potential security problem was recorded as CVE-2008-2371.
481    
482    12. For a pattern where the match had to start at the beginning or immediately
483        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
484        pcre_dfa_exec() could read past the end of the passed subject if there was
485        no match. To help with detecting such bugs (e.g. with valgrind), I modified
486        pcretest so that it places the subject at the end of its malloc-ed buffer.
487    
488    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
489        exec() might read past the end of the data buffer in UTF-8 mode.
490    
491    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
492        the data contained the byte 0x85 as part of a UTF-8 character within its
493        first line. This applied both to normal and DFA matching.
494    
495    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
496        /^[^d]*?$/8 failed to match "abc".
497    
498    16. Added a missing copyright notice to pcrecpp_internal.h.
499    
500    17. Make it more clear in the documentation that values returned from
501        pcre_exec() in ovector are byte offsets, not character counts.
502    
503    18. Tidied a few places to stop certain compilers from issuing warnings.
504    
505    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
506        supplied by Stefan Weber. I made a further small update for 7.8 because
507        there is a change of source arrangements: the pcre_searchfuncs.c module is
508        replaced by pcre_ucd.c.
509    
510    
511    Version 7.7 07-May-08
512    ---------------------
513    
514    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
515        a string to a long long, pretend we don't even have a long long." This is
516        done by checking for the strtoq, strtoll, and _strtoi64 functions.
517    
518    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
519        pre-7.6 versions, which defined a global no_arg variable instead of putting
520        it in the RE class. (See also #8 below.)
521    
522    3.  Remove a line of dead code, identified by coverity and reported by Nuno
523        Lopes.
524    
525    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
526    
527        (1) The include/exclude patterns were being applied to the whole pathnames
528            of files, instead of just to the final components.
529    
530        (2) If there was more than one level of directory, the subdirectories were
531            skipped unless they satisfied the include/exclude conditions. This is
532            inconsistent with GNU grep (and could even be seen as contrary to the
533            pcregrep specification - which I improved to make it absolutely clear).
534            The action now is always to scan all levels of directory, and just
535            apply the include/exclude patterns to regular files.
536    
537    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
538        --exclude_dir in the tests to avoid scanning .svn directories.
539    
540    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
541        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
542        doesn't support NULs in patterns.
543    
544    7.  Added some missing "const"s to declarations of static tables in
545        pcre_compile.c and pcre_dfa_exec.c.
546    
547    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
548        caused by fix #2  above. (Subsequently also a second patch to fix the
549        first patch. And a third patch - this was a messy problem.)
550    
551    9.  Applied Craig's patch to remove the use of push_back().
552    
553    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
554        matching function regexec().
555    
556    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
557        which, however, unlike Perl's \g{...}, are subroutine calls, not back
558        references. PCRE supports relative numbers with this syntax (I don't think
559        Oniguruma does).
560    
561    12. Previously, a group with a zero repeat such as (...){0} was completely
562        omitted from the compiled regex. However, this means that if the group
563        was called as a subroutine from elsewhere in the pattern, things went wrong
564        (an internal error was given). Such groups are now left in the compiled
565        pattern, with a new opcode that causes them to be skipped at execution
566        time.
567    
568    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
569        to the way PCRE behaves:
570    
571        (a) A lone ] character is dis-allowed (Perl treats it as data).
572    
573        (b) A back reference to an unmatched subpattern matches an empty string
574            (Perl fails the current match path).
575    
576        (c) A data ] in a character class must be notated as \] because if the
577            first data character in a class is ], it defines an empty class. (In
578            Perl it is not possible to have an empty class.) The empty class []
579            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
580            The negative empty class [^] matches any one character, independently
581            of the DOTALL setting.
582    
583    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
584        non-existent subpattern following a character class starting with ']' and
585        containing () gave an internal compiling error instead of "reference to
586        non-existent subpattern". Fortunately, when the pattern did exist, the
587        compiled code was correct. (When scanning forwards to check for the
588        existencd of the subpattern, it was treating the data ']' as terminating
589        the class, so got the count wrong. When actually compiling, the reference
590        was subsequently set up correctly.)
591    
592    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
593        it was being rejected as not supported by pcre_dfa_exec(), even though
594        other assertions are supported. I have made pcre_dfa_exec() support
595        (*FAIL).
596    
597    16. The implementation of 13c above involved the invention of a new opcode,
598        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
599        cannot be changed at match time, I realized I could make a small
600        improvement to matching performance by compiling OP_ALLANY instead of
601        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
602        on the OP_ANY path.
603    
604    17. Compiling pcretest on Windows with readline support failed without the
605        following two fixes: (1) Make the unistd.h include conditional on
606        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
607    
608    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
609        ncurses library to be included for pcretest when ReadLine support is
610        requested, but also to allow for it to be overridden. This patch came from
611        Daniel Bergström.
612    
613    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
614        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
615        any errors with the current Unicode tables. Thanks to Peter Kankowski for
616        spotting this.
617    
618    
619    Version 7.6 28-Jan-08
620    ---------------------
621    
622    1.  A character class containing a very large number of characters with
623        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
624        overflow.
625    
626    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
627        HAVE_LONG_LONG is not defined.
628    
629    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
630        bring them up to date and include new features. This patch includes:
631    
632        - Fixed PH's badly added libz and libbz2 support.
633        - Fixed a problem with static linking.
634        - Added pcredemo. [But later removed - see 7 below.]
635        - Fixed dftables problem and added an option.
636        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
637            HAVE_LONG_LONG.
638        - Added readline support for pcretest.
639        - Added an listing of the option settings after cmake has run.
640    
641    4.  A user submitted a patch to Makefile that makes it easy to create
642        "pcre.dll" under mingw when using Configure/Make. I added stuff to
643        Makefile.am that cause it to include this special target, without
644        affecting anything else. Note that the same mingw target plus all
645        the other distribution libraries and programs are now supported
646        when configuring with CMake (see 6 below) instead of with
647        Configure/Make.
648    
649    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
650        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
651        exported in the Windows port". It has not yet been confirmed that the patch
652        solves the problem, but it does no harm.
653    
654    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
655        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
656        with CMake, and also correct the comment about stack recursion.
657    
658    7.  Remove the automatic building of pcredemo from the ./configure system and
659        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
660        of a program that users should build themselves after PCRE is installed, so
661        building it automatically is not really right. What is more, it gave
662        trouble in some build environments.
663    
664    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
665    
666    
667    Version 7.5 10-Jan-08
668    ---------------------
669    
670    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
671        values in parens when parsing an RE using the C++ wrapper."
672    
673    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
674        Characters greater than 255 were excluded from the class instead of being
675        included.
676    
677    3.  The same bug as (2) above applied to negated POSIX classes such as
678        [:^space:].
679    
680    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
681        defined or documented. It seems to have been a typo for PCRE_STATIC, so
682        I have changed it.
683    
684    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
685        first named subpattern) and a construct such as (?&a) would reference the
686        first named subpattern whose name started with "a" (in other words, the
687        length check was missing). Both these problems are fixed. "Subpattern name
688        expected" is now given for (?&) (a zero-length name), and this patch also
689        makes it give the same error for \k'' (previously it complained that that
690        was a reference to a non-existent subpattern).
691    
692    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
693        this is right because (?- can be followed by option settings as well as by
694        digits. I have, however, made the messages clearer.
695    
696    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
697        than the number used in the conditional) now cause a compile-time error.
698        This is actually not compatible with Perl, which accepts such patterns, but
699        treats the conditional as always being FALSE (as PCRE used to), but it
700        seems to me that giving a diagnostic is better.
701    
702    8.  Change "alphameric" to the more common word "alphanumeric" in comments
703        and messages.
704    
705    9.  Fix two occurrences of "backslash" in comments that should have been
706        "backspace".
707    
708    10. Remove two redundant lines of code that can never be obeyed (their function
709        was moved elsewhere).
710    
711    11. The program that makes PCRE's Unicode character property table had a bug
712        which caused it to generate incorrect table entries for sequences of
713        characters that have the same character type, but are in different scripts.
714        It amalgamated them into a single range, with the script of the first of
715        them. In other words, some characters were in the wrong script. There were
716        thirteen such cases, affecting characters in the following ranges:
717    
718          U+002b0 - U+002c1
719          U+0060c - U+0060d
720          U+0061e - U+00612
721          U+0064b - U+0065e
722          U+0074d - U+0076d
723          U+01800 - U+01805
724          U+01d00 - U+01d77
725          U+01d9b - U+01dbf
726          U+0200b - U+0200f
727          U+030fc - U+030fe
728          U+03260 - U+0327f
729          U+0fb46 - U+0fbb1
730          U+10450 - U+1049d
731    
732    12. The -o option (show only the matching part of a line) for pcregrep was not
733        compatible with GNU grep in that, if there was more than one match in a
734        line, it showed only the first of them. It now behaves in the same way as
735        GNU grep.
736    
737    13. If the -o and -v options were combined for pcregrep, it printed a blank
738        line for every non-matching line. GNU grep prints nothing, and pcregrep now
739        does the same. The return code can be used to tell if there were any
740        non-matching lines.
741    
742    14. Added --file-offsets and --line-offsets to pcregrep.
743    
744    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
745        infinitely looping recursion. The bug was that positive lookaheads were not
746        being skipped when checking for a possible empty match (negative lookaheads
747        and both kinds of lookbehind were skipped).
748    
749    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
750        inclusion of <windows.h> to before rather than after the definition of
751        INVALID_FILE_ATTRIBUTES (patch from David Byron).
752    
753    17. Specifying a possessive quantifier with a specific limit for a Unicode
754        character property caused pcre_compile() to compile bad code, which led at
755        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
756        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
757        caused the error; without that there was no problem.
758    
759    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
760    
761    19. Added --enable-pcretest-libreadline.
762    
763    20. In pcrecpp.cc, the variable 'count' was incremented twice in
764        RE::GlobalReplace(). As a result, the number of replacements returned was
765        double what it should be. I removed one of the increments, but Craig sent a
766        later patch that removed the other one (the right fix) and added unit tests
767        that check the return values (which was not done before).
768    
769    21. Several CMake things:
770    
771        (1) Arranged that, when cmake is used on Unix, the libraries end up with
772            the names libpcre and libpcreposix, not just pcre and pcreposix.
773    
774        (2) The above change means that pcretest and pcregrep are now correctly
775            linked with the newly-built libraries, not previously installed ones.
776    
777        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
778    
779    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
780        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
781        UTF-8 newline character). The key issue is that the pattern starts .*;
782        this means that the match must be either at the beginning, or after a
783        newline. The bug was in the code for advancing after a failed match and
784        checking that the new position followed a newline. It was not taking
785        account of UTF-8 characters correctly.
786    
787    23. PCRE was behaving differently from Perl in the way it recognized POSIX
788        character classes. PCRE was not treating the sequence [:...:] as a
789        character class unless the ... were all letters. Perl, however, seems to
790        allow any characters between [: and :], though of course it rejects as
791        unknown any "names" that contain non-letters, because all the known class
792        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
793        for example, whereas PCRE did not - it did not recognize a POSIX character
794        class. This seemed a bit dangerous, so the code has been changed to be
795        closer to Perl. The behaviour is not identical to Perl, because PCRE will
796        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
797        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
798        Perl does, and where it didn't before.
799    
800    24. Rewrite so as to remove the single use of %n from pcregrep because in some
801        Windows environments %n is disabled by default.
802    
803    
804    Version 7.4 21-Sep-07
805    ---------------------
806    
807    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
808        means that a class such as [\s] counted as "explicit reference to CR or
809        LF". That isn't really right - the whole point of the change was to try to
810        help when there was an actual mention of one of the two characters. So now
811        the change happens only if \r or \n (or a literal CR or LF) character is
812        encountered.
813    
814    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
815        of both had grown to the point where there were only 3 bits left.
816        Fortunately, there was spare space in the data structure, and so I have
817        moved the internal flags into a new 16-bit field to free up more option
818        bits.
819    
820    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
821        but did not set the internal JCHANGED flag - either of these is enough to
822        control the way the "get" function works - but the PCRE_INFO_JCHANGED
823        facility is supposed to tell if (?J) was ever used, so now (?J) at the
824        start sets both bits.
825    
826    4.  Added options (at build time, compile time, exec time) to change \R from
827        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
828    
829    5.  doc/pcresyntax.html was missing from the distribution.
830    
831    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
832        compatibility, even though it is no longer used.
833    
834    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
835        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
836        windows.h file is present (where different names are used). [This was
837        reversed later after testing - see 16 below.]
838    
839    8.  Changed all #include <config.h> to #include "config.h". There were also
840        some further <pcre.h> cases that I changed to "pcre.h".
841    
842    9.  When pcregrep was used with the --colour option, it missed the line ending
843        sequence off the lines that it output.
844    
845    10. It was pointed out to me that arrays of string pointers cause lots of
846        relocations when a shared library is dynamically loaded. A technique of
847        using a single long string with a table of offsets can drastically reduce
848        these. I have refactored PCRE in four places to do this. The result is
849        dramatic:
850    
851          Originally:                          290
852          After changing UCP table:            187
853          After changing error message table:   43
854          After changing table of "verbs"       36
855          After changing table of Posix names   22
856    
857        Thanks to the folks working on Gregex for glib for this insight.
858    
859    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
860        unicode-properties was also set.
861    
862    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
863    
864    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
865        checked only for CRLF.
866    
867    14. Added casts to pcretest.c to avoid compiler warnings.
868    
869    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
870    
871    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
872        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
873        entirely. This removes changes made in 7 above.
874    
875    17. The CMake files have been updated, and there is now more information about
876        building with CMake in the NON-UNIX-USE document.
877    
878    
879    Version 7.3 28-Aug-07
880    ---------------------
881    
882     1. In the rejigging of the build system that eventually resulted in 7.1, the
883        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
884        brackets there is not right, since it causes compilers to look for an
885        installed pcre.h, not the version that is in the source that is being
886        compiled (which of course may be different). I have changed it back to:
887    
888          #include "pcre.h"
889    
890        I have a vague recollection that the change was concerned with compiling in
891        different directories, but in the new build system, that is taken care of
892        by the VPATH setting the Makefile.
893    
894     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
895        when the subject happened to end in the byte 0x85 (e.g. if the last
896        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
897        characters but of course it shouldn't be taken as a newline when it is part
898        of another character. The bug was that, for an unlimited repeat of . in
899        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
900        characters when looking for a newline.
901    
902     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
903    
904     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
905        in debug output.
906    
907     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
908        long printing in the pcrecpp unittest when running under MinGW.
909    
910     6. ESC_K was left out of the EBCDIC table.
911    
912     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
913        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
914        limit also applies to "virtual nesting" when a pattern is recursive, and in
915        this case 1000 isn't so big. I have been able to remove this limit at the
916        expense of backing off one optimization in certain circumstances. Normally,
917        when pcre_exec() would call its internal match() function recursively and
918        immediately return the result unconditionally, it uses a "tail recursion"
919        feature to save stack. However, when a subpattern that can match an empty
920        string has an unlimited repetition quantifier, it no longer makes this
921        optimization. That gives it a stack frame in which to save the data for
922        checking that an empty string has been matched. Previously this was taken
923        from the 1000-entry workspace that had been reserved. So now there is no
924        explicit limit, but more stack is used.
925    
926     8. Applied Daniel's patches to solve problems with the import/export magic
927        syntax that is required for Windows, and which was going wrong for the
928        pcreposix and pcrecpp parts of the library. These were overlooked when this
929        problem was solved for the main library.
930    
931     9. There were some crude static tests to avoid integer overflow when computing
932        the size of patterns that contain repeated groups with explicit upper
933        limits. As the maximum quantifier is 65535, the maximum group length was
934        set at 30,000 so that the product of these two numbers did not overflow a
935        32-bit integer. However, it turns out that people want to use groups that
936        are longer than 30,000 bytes (though not repeat them that many times).
937        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
938        made it possible to implement the integer overflow checks in a much more
939        dynamic way, which I have now done. The artificial limitation on group
940        length has been removed - we now have only the limit on the total length of
941        the compiled pattern, which depends on the LINK_SIZE setting.
942    
943    10. Fixed a bug in the documentation for get/copy named substring when
944        duplicate names are permitted. If none of the named substrings are set, the
945        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
946        empty string.
947    
948    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
949        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
950        because the ] is interpreted as the first data character and the
951        terminating ] is not found. PCRE has been made compatible with Perl in this
952        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
953        cause memory overwriting.
954    
955    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
956        string has been matched (to stop an infinite loop). It was not recognizing
957        a conditional subpattern that could match an empty string if that
958        subpattern was within another subpattern. For example, it looped when
959        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
960        condition was not nested. This bug has been fixed.
961    
962    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
963        past the start of the subject in the presence of bytes with the top bit
964        set, for example "\x8aBCD".
965    
966    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
967        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
968    
969    14. Optimized (?!) to (*FAIL).
970    
971    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
972        This restricts code points to be within the range 0 to 0x10FFFF, excluding
973        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
974        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
975        does: it's just the validity check that is more restrictive.
976    
977    16. Inserted checks for integer overflows during escape sequence (backslash)
978        processing, and also fixed erroneous offset values for syntax errors during
979        backslash processing.
980    
981    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
982        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
983    
984    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
985        caused an overrun.
986    
987    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
988        something other than just ASCII characters) inside a group that had an
989        unlimited repeat caused a loop at compile time (while checking to see
990        whether the group could match an empty string).
991    
992    20. Debugging a pattern containing \p or \P could cause a crash. For example,
993        [\P{Any}] did so. (Error in the code for printing property names.)
994    
995    21. An orphan \E inside a character class could cause a crash.
996    
997    22. A repeated capturing bracket such as (A)? could cause a wild memory
998        reference during compilation.
999    
1000    23. There are several functions in pcre_compile() that scan along a compiled
1001        expression for various reasons (e.g. to see if it's fixed length for look
1002        behind). There were bugs in these functions when a repeated \p or \P was
1003        present in the pattern. These operators have additional parameters compared
1004        with \d, etc, and these were not being taken into account when moving along
1005        the compiled data. Specifically:
1006    
1007        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1008            length.
1009    
1010        (b) An item such as \pL+ within a repeated group could cause crashes or
1011            loops.
1012    
1013        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1014            "reference to non-existent subpattern" error.
1015    
1016        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1017    
1018    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1019        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1020    
1021    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1022    
1023    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1024        character were causing crashes (broken optimization).
1025    
1026    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1027        \p or \P) caused a compile-time loop.
1028    
1029    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1030        break. For example, the unstudied pattern [\r\n]A does not match the string
1031        "\r\nA" because change 7.0/46 below moves the current point on by two
1032        characters after failing to match at the start. However, the pattern \nA
1033        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1034        the same is true. There doesn't seem any very clean way out of this, but
1035        what I have chosen to do makes the common cases work: PCRE now takes note
1036        of whether there can be an explicit match for \r or \n anywhere in the
1037        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1038        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1039        pattern has explicit CR or LF references.
1040    
1041    29. Added (*CR) etc for changing newline setting at start of pattern.
1042    
1043    
1044    Version 7.2 19-Jun-07
1045    ---------------------
1046    
1047     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1048        which is apparently normally available under Windows.
1049    
1050     2. Re-jig the pcregrep tests with different newline settings in an attempt
1051        to make them independent of the local environment's newline setting.
1052    
1053     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1054    
1055     4. Some of the "internals" tests were previously cut out when the link size
1056        was not 2, because the output contained actual offsets. The recent new
1057        "Z" feature of pcretest means that these can be cut out, making the tests
1058        usable with all link sizes.
1059    
1060     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1061        stack recursion. This gives a massive performance boost under BSD, but just
1062        a small improvement under Linux. However, it saves one field in the frame
1063        in all cases.
1064    
1065     6. Added more features from the forthcoming Perl 5.10:
1066    
1067        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1068            recursion call. It refers to the nth most recently opened parentheses.
1069    
1070        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1071            to be opened parentheses.
1072    
1073        (c) Conditions that refer to capturing parentheses can be specified
1074            relatively, for example, (?(-2)... or (?(+3)...
1075    
1076        (d) \K resets the start of the current match so that everything before
1077            is not part of it.
1078    
1079        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1080    
1081        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1082            reference syntax.
1083    
1084        (g) (?| introduces a group in which the numbering of parentheses in each
1085            alternative starts with the same number.
1086    
1087        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1088    
1089     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1090        PCRE_INFO_JCHANGED.
1091    
1092     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1093        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1094        for detecting groups that can match an empty string.
1095    
1096     9. A pattern with a very large number of alternatives (more than several
1097        hundred) was running out of internal workspace during the pre-compile
1098        phase, where pcre_compile() figures out how much memory will be needed. A
1099        bit of new cunning has reduced the workspace needed for groups with
1100        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1101        workspace instead of running out of the 4096 that are available.
1102    
1103    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1104    
1105    11. Applied patch from Google to remove an optimization that didn't quite work.
1106        The report of the bug said:
1107    
1108          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1109          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1110          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1111    
1112    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1113        it matched the wrong number of bytes.
1114    
1115    
1116    Version 7.1 24-Apr-07
1117    ---------------------
1118    
1119     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1120        that is more "standard", making use of automake and other Autotools. There
1121        is some re-arrangement of the files and adjustment of comments consequent
1122        on this.
1123    
1124     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1125        for recursive directory scanning broke on some systems because the files
1126        are not scanned in any specific order and on different systems the order
1127        was different. A call to "sort" has been inserted into RunGrepTest for the
1128        approprate test as a short-term fix. In the longer term there may be an
1129        alternative.
1130    
1131     3. I had an email from Eric Raymond about problems translating some of PCRE's
1132        man pages to HTML (despite the fact that I distribute HTML pages, some
1133        people do their own conversions for various reasons). The problems
1134        concerned the use of low-level troff macros .br and .in. I have therefore
1135        removed all such uses from the man pages (some were redundant, some could
1136        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1137        HTML has been updated to handle .nf/.fi and to complain if it encounters
1138        .br or .in.
1139    
1140     4. Updated comments in configure.ac that get placed in config.h.in and also
1141        arranged for config.h to be included in the distribution, with the name
1142        config.h.generic, for the benefit of those who have to compile without
1143        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1144    
1145     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1146        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1147        makevp.bat for the current PCRE, using the additional files
1148        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1149    
1150     6. A Windows user reported a minor discrepancy with test 2, which turned out
1151        to be caused by a trailing space on an input line that had got lost in his
1152        copy. The trailing space was an accident, so I've just removed it.
1153    
1154     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1155        that is needed.
1156    
1157     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1158        as "const" (a) because they are and (b) because it helps the PHP
1159        maintainers who have recently made a script to detect big data structures
1160        in the php code that should be moved to the .rodata section. I remembered
1161        to update Builducptable as well, so it won't revert if ucptable.h is ever
1162        re-created.
1163    
1164     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1165        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1166        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1167        support is not required. This saves 1.5-2K of code, which is important in
1168        some applications.
1169    
1170        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1171        so as not to refer to the tables, even though these functions will never be
1172        called when UTF-8 support is disabled. Otherwise there are problems with a
1173        shared library.
1174    
1175    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1176    
1177        (a) It was defining its arguments as char * instead of void *.
1178    
1179        (b) It was assuming that all moves were upwards in memory; this was true
1180            a long time ago when I wrote it, but is no longer the case.
1181    
1182        The emulated memove() is provided for those environments that have neither
1183        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1184        is clearly not the case, as these two bugs were recently reported.
1185    
1186    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1187        and Detrail to create the HTML documentation, the .txt form of the man
1188        pages, and it removes trailing spaces from listed files. It also creates
1189        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1190        case, it wraps all the #defines with #ifndefs. This script should be run
1191        before "make dist".
1192    
1193    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1194        with Unicode property support.
1195    
1196        (a) For a maximizing quantifier, if the two different cases of the
1197            character were of different lengths in their UTF-8 codings (there are
1198            some cases like this - I found 11), and the matching function had to
1199            back up over a mixture of the two cases, it incorrectly assumed they
1200            were both the same length.
1201    
1202        (b) When PCRE was configured to use the heap rather than the stack for
1203            recursion during matching, it was not correctly preserving the data for
1204            the other case of a UTF-8 character when checking ahead for a match
1205            while processing a minimizing repeat. If the check also involved
1206            matching a wide character, but failed, corruption could cause an
1207            erroneous result when trying to check for a repeat of the original
1208            character.
1209    
1210    13. Some tidying changes to the testing mechanism:
1211    
1212        (a) The RunTest script now detects the internal link size and whether there
1213            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1214            values substituted by "configure". (The RunGrepTest script already did
1215            this for UTF-8.) The configure.ac script no longer substitutes the
1216            relevant variables.
1217    
1218        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1219            with length and offset values. This means that the output is different
1220            for different internal link sizes. Test 2 is skipped for link sizes
1221            other than 2 because of this, bypassing the problem. Unfortunately,
1222            there was also a test in test 3 (the locale tests) that used /B and
1223            failed for link sizes other than 2. Rather than cut the whole test out,
1224            I have added a new /Z option to pcretest that replaces the length and
1225            offset values with spaces. This is now used to make test 3 independent
1226            of link size. (Test 2 will be tidied up later.)
1227    
1228    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1229        segmentation fault instead of returning the appropriate error message.
1230    
1231    15. In multiline mode when the newline sequence was set to "any", the pattern
1232        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1233        This doesn't seem right; it now treats the CRLF combination as the line
1234        ending, and so does not match in that case. It's only a pattern such as ^$
1235        that would hit this one: something like ^ABC$ would have failed after \r
1236        and then tried again after \r\n.
1237    
1238    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1239        in an attempt to make files that differ only in their line terminators
1240        compare equal. This works on Linux.
1241    
1242    17. Under certain error circumstances pcregrep might try to free random memory
1243        as it exited. This is now fixed, thanks to valgrind.
1244    
1245    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1246        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1247        was because its rules for how to advance for /g after matching an empty
1248        string at the end of a line did not allow for this case. They now check for
1249        it specially.
1250    
1251    20. pcretest is supposed to handle patterns and data of any length, by
1252        extending its buffers when necessary. It was getting this wrong when the
1253        buffer for a data line had to be extended.
1254    
1255    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1256        CRLF as a newline sequence.
1257    
1258    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1259        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1260        I have nevertheless tidied it up.
1261    
1262    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1263    
1264    24. Added a man page for pcre-config.
1265    
1266    
1267    Version 7.0 19-Dec-06
1268    ---------------------
1269    
1270     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1271        moving to gcc 4.1.1.
1272    
1273     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1274        sys/time.h, which is documented as needed for this function. It doesn't
1275        seem to matter on Linux, but it showed up on some releases of OS X.
1276    
1277     3. It seems that there are systems where bytes whose values are greater than
1278        127 match isprint() in the "C" locale. The "C" locale should be the
1279        default when a C program starts up. In most systems, only ASCII printing
1280        characters match isprint(). This difference caused the output from pcretest
1281        to vary, making some of the tests fail. I have changed pcretest so that:
1282    
1283        (a) When it is outputting text in the compiled version of a pattern, bytes
1284            other than 32-126 are always shown as hex escapes.
1285    
1286        (b) When it is outputting text that is a matched part of a subject string,
1287            it does the same, unless a different locale has been set for the match
1288            (using the /L modifier). In this case, it uses isprint() to decide.
1289    
1290     4. Fixed a major bug that caused incorrect computation of the amount of memory
1291        required for a compiled pattern when options that changed within the
1292        pattern affected the logic of the preliminary scan that determines the
1293        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1294        that the computed length was too small. The symptoms of this bug were
1295        either the PCRE error "internal error: code overflow" from pcre_compile(),
1296        or a glibc crash with a message such as "pcretest: free(): invalid next
1297        size (fast)". Examples of patterns that provoked this bug (shown in
1298        pcretest format) are:
1299    
1300          /(?-x: )/x
1301          /(?x)(?-x: \s*#\s*)/
1302          /((?i)[\x{c0}])/8
1303          /(?i:[\x{c0}])/8
1304    
1305        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1306        is now done differently.
1307    
1308     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1309        wrapper classes; (b) implement a new function in the C++ scanner that is
1310        more efficient than the old way of doing things because it avoids levels of
1311        recursion in the regex matching; (c) add a paragraph to the documentation
1312        for the FullMatch() function.
1313    
1314     6. The escape sequence \n was being treated as whatever was defined as
1315        "newline". Not only was this contrary to the documentation, which states
1316        that \n is character 10 (hex 0A), but it also went horribly wrong when
1317        "newline" was defined as CRLF. This has been fixed.
1318    
1319     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1320        was being set to -1 for the "end of line" case (supposedly a value that no
1321        character can have). Though this value is never used (the check for end of
1322        line is "zero bytes in current character"), it caused compiler complaints.
1323        I've changed it to 0xffffffff.
1324    
1325     8. In pcre_version.c, the version string was being built by a sequence of
1326        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1327        string (as it is for production releases) called a macro with an empty
1328        argument. The C standard says the result of this is undefined. The gcc
1329        compiler treats it as an empty string (which was what was wanted) but it is
1330        reported that Visual C gives an error. The source has been hacked around to
1331        avoid this problem.
1332    
1333     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1334        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1335        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1336        of them did).
1337    
1338    10. Originally, pcretest opened its input and output without "b"; then I was
1339        told that "b" was needed in some environments, so it was added for release
1340        5.0 to both the input and output. (It makes no difference on Unix-like
1341        systems.) Later I was told that it is wrong for the input on Windows. I've
1342        now abstracted the modes into two macros, to make it easier to fiddle with
1343        them, and removed "b" from the input mode under Windows.
1344    
1345    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1346    
1347    12. Added -help and --help to pcretest as an official way of being reminded
1348        of the options.
1349    
1350    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1351        and pcrecpp.cc because they annoy compilers at high warning levels.
1352    
1353    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1354    
1355    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1356        scripts are not C programs :-) and which was not noticed because it works
1357        on Linux.
1358    
1359    16. pcretest is supposed to handle any length of pattern and data line (as one
1360        line or as a continued sequence of lines) by extending its input buffer if
1361        necessary. This feature was broken for very long pattern lines, leading to
1362        a string of junk being passed to pcre_compile() if the pattern was longer
1363        than about 50K.
1364    
1365    17. I have done a major re-factoring of the way pcre_compile() computes the
1366        amount of memory needed for a compiled pattern. Previously, there was code
1367        that made a preliminary scan of the pattern in order to do this. That was
1368        OK when PCRE was new, but as the facilities have expanded, it has become
1369        harder and harder to keep it in step with the real compile phase, and there
1370        have been a number of bugs (see for example, 4 above). I have now found a
1371        cunning way of running the real compile function in a "fake" mode that
1372        enables it to compute how much memory it would need, while actually only
1373        ever using a few hundred bytes of working memory and without too many
1374        tests of the mode. This should make future maintenance and development
1375        easier. A side effect of this work is that the limit of 200 on the nesting
1376        depth of parentheses has been removed (though this was never a serious
1377        limitation, I suspect). However, there is a downside: pcre_compile() now
1378        runs more slowly than before (30% or more, depending on the pattern). I
1379        hope this isn't a big issue. There is no effect on runtime performance.
1380    
1381    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1382        newline (only possible for the last line of a file) and it was a
1383        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1384    
1385    19. Added additional timing features to pcretest. (1) The -tm option now times
1386        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1387        separate command line item, by a number that specifies the number of
1388        repeats to use when timing. The default is 50000; this gives better
1389        precision, but takes uncomfortably long for very large patterns.
1390    
1391    20. Extended pcre_study() to be more clever in cases where a branch of a
1392        subpattern has no definite first character. For example, (a*|b*)[cd] would
1393        previously give no result from pcre_study(). Now it recognizes that the
1394        first character must be a, b, c, or d.
1395    
1396    21. There was an incorrect error "recursive call could loop indefinitely" if
1397        a subpattern (or the entire pattern) that was being tested for matching an
1398        empty string contained only one non-empty item after a nested subpattern.
1399        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1400        incorrectly, because the \d was being skipped in the check.
1401    
1402    22. The pcretest program now has a new pattern option /B and a command line
1403        option -b, which is equivalent to adding /B to every pattern. This causes
1404        it to show the compiled bytecode, without the additional information that
1405        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1406        is the same as /B/I).
1407    
1408    23. A new optimization is now able automatically to treat some sequences such
1409        as a*b as a*+b. More specifically, if something simple (such as a character
1410        or a simple class like \d) has an unlimited quantifier, and is followed by
1411        something that cannot possibly match the quantified thing, the quantifier
1412        is automatically "possessified".
1413    
1414    24. A recursive reference to a subpattern whose number was greater than 39
1415        went wrong under certain circumstances in UTF-8 mode. This bug could also
1416        have affected the operation of pcre_study().
1417    
1418    25. Realized that a little bit of performance could be had by replacing
1419        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1420    
1421    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1422    
1423    27. Possessive quantifiers such as a++ were previously implemented by turning
1424        them into atomic groups such as ($>a+). Now they have their own opcodes,
1425        which improves performance. This includes the automatically created ones
1426        from 23 above.
1427    
1428    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1429        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1430        the first matched character to be a colon. This applied both to named and
1431        numbered groups.
1432    
1433    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1434    
1435    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1436        building PCRE on Windows easier, so I have included it in the distribution.
1437    
1438    31. There is now a check in pcretest against a ridiculously large number being
1439        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1440        loop, the loop is abandoned.
1441    
1442    32. Forward references to subpatterns in conditions such as (?(2)...) where
1443        subpattern 2 is defined later cause pcre_compile() to search forwards in
1444        the pattern for the relevant set of parentheses. This search went wrong
1445        when there were unescaped parentheses in a character class, parentheses
1446        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1447    
1448    33. "Subroutine" calls and backreferences were previously restricted to
1449        referencing subpatterns earlier in the regex. This restriction has now
1450        been removed.
1451    
1452    34. Added a number of extra features that are going to be in Perl 5.10. On the
1453        whole, these are just syntactic alternatives for features that PCRE had
1454        previously implemented using the Python syntax or my own invention. The
1455        other formats are all retained for compatibility.
1456    
1457        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1458            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1459            also .NET compatible.
1460    
1461        (b) A recursion or subroutine call to a named group can now be defined as
1462            (?&name) as well as (?P>name).
1463    
1464        (c) A backreference to a named group can now be defined as \k<name> or
1465            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1466            5.10, are also .NET compatible.
1467    
1468        (d) A conditional reference to a named group can now use the syntax
1469            (?(<name>) or (?('name') as well as (?(name).
1470    
1471        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1472            groups (named and numbered) that are never evaluated inline, but can be
1473            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1474            is always false. There may be only one alternative in such a group.
1475    
1476        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1477            as the simple (?(R). The condition is true only if the most recent
1478            recursion is that of the given number or name. It does not search out
1479            through the entire recursion stack.
1480    
1481        (g) The escape \gN or \g{N} has been added, where N is a positive or
1482            negative number, specifying an absolute or relative reference.
1483    
1484    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1485        some "unreachable code" warnings.
1486    
1487    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1488        things, this adds five new scripts.
1489    
1490    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1491        There were also incompatibilities regarding the handling of \Q..\E inside
1492        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1493        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1494    
1495    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1496        matches an empty string, and forcibly breaks the loop. There were bugs in
1497        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1498        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1499        separate and independent bugs (that affected different cases) have been
1500        fixed.
1501    
1502    39. Refactored the code to abolish the use of different opcodes for small
1503        capturing bracket numbers. This is a tidy that I avoided doing when I
1504        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1505        The new approach is not only tidier, it makes it possible to reduce the
1506        memory needed to fix the previous bug (38).
1507    
1508    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1509        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1510        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1511        mode.
1512    
1513    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1514        report.
1515    
1516    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1517        copy construction and assignment in the C++ wrapper.
1518    
1519    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1520        couple of bugs that could have given wrong results in the "--newline=crlf"
1521        case.
1522    
1523    44. Added a number of casts and did some reorganization of signed/unsigned int
1524        variables following suggestions from Dair Grant. Also renamed the variable
1525        "this" as "item" because it is a C++ keyword.
1526    
1527    45. Arranged for dftables to add
1528    
1529          #include "pcre_internal.h"
1530    
1531        to pcre_chartables.c because without it, gcc 4.x may remove the array
1532        definition from the final binary if PCRE is built into a static library and
1533        dead code stripping is activated.
1534    
1535    46. For an unanchored pattern, if a match attempt fails at the start of a
1536        newline sequence, and the newline setting is CRLF or ANY, and the next two
1537        characters are CRLF, advance by two characters instead of one.
1538    
1539    
1540    Version 6.7 04-Jul-06
1541    ---------------------
1542    
1543     1. In order to handle tests when input lines are enormously long, pcretest has
1544        been re-factored so that it automatically extends its buffers when
1545        necessary. The code is crude, but this _is_ just a test program. The
1546        default size has been increased from 32K to 50K.
1547    
1548     2. The code in pcre_study() was using the value of the re argument before
1549        testing it for NULL. (Of course, in any sensible call of the function, it
1550        won't be NULL.)
1551    
1552     3. The memmove() emulation function in pcre_internal.h, which is used on
1553        systems that lack both memmove() and bcopy() - that is, hardly ever -
1554        was missing a "static" storage class specifier.
1555    
1556     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1557        containing an extended class (one that cannot be represented by a bitmap
1558        because it contains high-valued characters or Unicode property items, e.g.
1559        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1560        pattern, but PCRE should not loop if you do not (it no longer does).
1561        [Detail: two cases were found: (a) a repeated subpattern containing an
1562        extended class; (b) a recursive reference to a subpattern that followed a
1563        previous extended class. It wasn't skipping over the extended class
1564        correctly when UTF-8 mode was not set.]
1565    
1566     5. A negated single-character class was not being recognized as fixed-length
1567        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1568        compile error "lookbehind assertion is not fixed length".
1569    
1570     6. The RunPerlTest auxiliary script was showing an unexpected difference
1571        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1572        write a Perl script that can interpret lines of an input file either as
1573        byte characters or as UTF-8, which is what "perltest" was being required to
1574        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1575        can't do is switch easily at run time between having the "use utf8;" pragma
1576        or not. In the end, I fudged it by using the RunPerlTest script to insert
1577        "use utf8;" explicitly for the UTF-8 tests.
1578    
1579     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1580        the end of the subject string, contrary to the documentation and to what
1581        Perl does. This was true of both matching functions. Now it matches only at
1582        the start of the subject and immediately after *internal* newlines.
1583    
1584     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1585        a pointer to an int instead of a pointer to an unsigned long int. This
1586        caused problems on 64-bit systems.
1587    
1588     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1589        instance of the 'standard' template library not being so standard".
1590    
1591    10. There was no check on the number of named subpatterns nor the maximum
1592        length of a subpattern name. The product of these values is used to compute
1593        the size of the memory block for a compiled pattern. By supplying a very
1594        long subpattern name and a large number of named subpatterns, the size
1595        computation could be caused to overflow. This is now prevented by limiting
1596        the length of names to 32 characters, and the number of named subpatterns
1597        to 10,000.
1598    
1599    11. Subpatterns that are repeated with specific counts have to be replicated in
1600        the compiled pattern. The size of memory for this was computed from the
1601        length of the subpattern and the repeat count. The latter is limited to
1602        65535, but there was no limit on the former, meaning that integer overflow
1603        could in principle occur. The compiled length of a repeated subpattern is
1604        now limited to 30,000 bytes in order to prevent this.
1605    
1606    12. Added the optional facility to have named substrings with the same name.
1607    
1608    13. Added the ability to use a named substring as a condition, using the
1609        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1610        are numbers (not recommended). Forward references are permitted.
1611    
1612    14. Added forward references in named backreferences (if you see what I mean).
1613    
1614    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1615        pattern could run off the end of the subject. For example, the pattern
1616        "(?s)(.{1,5})"8 did this with the subject "ab".
1617    
1618    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1619        PCRE_CASELESS was set when matching characters that were quantified with ?
1620        or *.
1621    
1622    17. A character class other than a single negated character that had a minimum
1623        but no maximum quantifier - for example [ab]{6,} - was not handled
1624        correctly by pce_dfa_exec(). It would match only one character.
1625    
1626    18. A valid (though odd) pattern that looked like a POSIX character
1627        class but used an invalid character after [ (for example [[,abc,]]) caused
1628        pcre_compile() to give the error "Failed: internal error: code overflow" or
1629        in some cases to crash with a glibc free() error. This could even happen if
1630        the pattern terminated after [[ but there just happened to be a sequence of
1631        letters, a binary zero, and a closing ] in the memory that followed.
1632    
1633    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1634        over the years. Originally (before any Unicode support), just the bottom 8
1635        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1636        output from "man perlunicode" includes this:
1637    
1638          The regular expression compiler produces polymorphic opcodes.  That
1639          is, the pattern adapts to the data and automatically switches to
1640          the Unicode character scheme when presented with Unicode data--or
1641          instead uses a traditional byte scheme when presented with byte
1642          data.
1643    
1644        Sadly, a wide octal escape does not cause a switch, and in a string with
1645        no other multibyte characters, these octal escapes are treated as before.
1646        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1647        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1648        Unicode string.
1649    
1650        I have not perpetrated such confusion in PCRE. Up till now, it took just
1651        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1652        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1653        translate to the appropriate multibyte character.
1654    
1655    29. Applied some refactoring to reduce the number of warnings from Microsoft
1656        and Borland compilers. This has included removing the fudge introduced
1657        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1658        a warning about an unused variable.
1659    
1660    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1661        characters since release 4.0, because Perl (from release 5.004) does not.
1662        [Or at least, is documented not to: some releases seem to be in conflict
1663        with the documentation.] However, when a pattern was studied with
1664        pcre_study() and all its branches started with \s, PCRE still included VT
1665        as a possible starting character. Of course, this did no harm; it just
1666        caused an unnecessary match attempt.
1667    
1668    22. Removed a now-redundant internal flag bit that recorded the fact that case
1669        dependency changed within the pattern. This was once needed for "required
1670        byte" processing, but is no longer used. This recovers a now-scarce options
1671        bit. Also moved the least significant internal flag bit to the most-
1672        significant bit of the word, which was not previously used (hangover from
1673        the days when it was an int rather than a uint) to free up another bit for
1674        the future.
1675    
1676    23. Added support for CRLF line endings as well as CR and LF. As well as the
1677        default being selectable at build time, it can now be changed at runtime
1678        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1679        specify that it is scanning data with non-default line endings.
1680    
1681    24. Changed the definition of CXXLINK to make it agree with the definition of
1682        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1683    
1684    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1685        recursions. This makes a big different to stack usage for some patterns.
1686    
1687    26. If a subpattern containing a named recursion or subroutine reference such
1688        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1689        the space required for the compiled pattern went wrong and gave too small a
1690        value. Depending on the environment, this could lead to "Failed: internal
1691        error: code overflow at offset 49" or "glibc detected double free or
1692        corruption" errors.
1693    
1694    27. Applied patches from Google (a) to support the new newline modes and (b) to
1695        advance over multibyte UTF-8 characters in GlobalReplace.
1696    
1697    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1698        difference for some implementation of PCRE in some Windows version.
1699    
1700    29. Added some extra testing facilities to pcretest:
1701    
1702        \q<number>   in a data line sets the "match limit" value
1703        \Q<number>   in a data line sets the "match recursion limt" value
1704        -S <number>  sets the stack size, where <number> is in megabytes
1705    
1706        The -S option isn't available for Windows.
1707    
1708    
1709    Version 6.6 06-Feb-06
1710    ---------------------
1711    
1712     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1713        in pcreposix.h. I have copied the definition from pcre.h.
1714    
1715     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1716        because pcre.h is no longer a built file.
1717    
1718     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1719        not normally included in the compiled code.
1720    
1721    
1722    Version 6.5 01-Feb-06
1723    ---------------------
1724    
1725     1. When using the partial match feature with pcre_dfa_exec(), it was not
1726        anchoring the second and subsequent partial matches at the new starting
1727        point. This could lead to incorrect results. For example, with the pattern
1728        /1234/, partially matching against "123" and then "a4" gave a match.
1729    
1730     2. Changes to pcregrep:
1731    
1732        (a) All non-match returns from pcre_exec() were being treated as failures
1733            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1734            error message is output. Some extra information is given for the
1735            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1736            probably the only errors that are likely to be caused by users (by
1737            specifying a regex that has nested indefinite repeats, for instance).
1738            If there are more than 20 of these errors, pcregrep is abandoned.
1739    
1740        (b) A binary zero was treated as data while matching, but terminated the
1741            output line if it was written out. This has been fixed: binary zeroes
1742            are now no different to any other data bytes.
1743    
1744        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1745            used to set a locale for matching. The --locale=xxxx long option has
1746            been added (no short equivalent) to specify a locale explicitly on the
1747            pcregrep command, overriding the environment variables.
1748    
1749        (d) When -B was used with -n, some line numbers in the output were one less
1750            than they should have been.
1751    
1752        (e) Added the -o (--only-matching) option.
1753    
1754        (f) If -A or -C was used with -c (count only), some lines of context were
1755            accidentally printed for the final match.
1756    
1757        (g) Added the -H (--with-filename) option.
1758    
1759        (h) The combination of options -rh failed to suppress file names for files
1760            that were found from directory arguments.
1761    
1762        (i) Added the -D (--devices) and -d (--directories) options.
1763    
1764        (j) Added the -F (--fixed-strings) option.
1765    
1766        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1767    
1768        (l) Added the --colo(u)r option.
1769    
1770        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1771            is not present by default.
1772    
1773     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1774        items such as (?R) or (?1), when the recursion could match a number of
1775        alternatives. If it matched one of the alternatives, but subsequently,
1776        outside the recursion, there was a failure, the code tried to back up into
1777        the recursion. However, because of the way PCRE is implemented, this is not
1778        possible, and the result was an incorrect result from the match.
1779    
1780        In order to prevent this happening, the specification of recursion has
1781        been changed so that all such subpatterns are automatically treated as
1782        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1783    
1784     4. I had overlooked the fact that, in some locales, there are characters for
1785        which isalpha() is true but neither isupper() nor islower() are true. In
1786        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1787        and ordfeminine) are like this. This affected the treatment of \w and \W
1788        when they appeared in character classes, but not when they appeared outside
1789        a character class. The bit map for "word" characters is now created
1790        separately from the results of isalnum() instead of just taking it from the
1791        upper, lower, and digit maps. (Plus the underscore character, of course.)
1792    
1793     5. The above bug also affected the handling of POSIX character classes such as
1794        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1795        permanent tables. Instead, the bit maps for such a class were previously
1796        created as the appropriate unions of the upper, lower, and digit bitmaps.
1797        Now they are created by subtraction from the [[:word:]] class, which has
1798        its own bitmap.
1799    
1800     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1801        It is created by subtracting the vertical space characters (\x09, \x0a,
1802        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1803        subtraction was done in the overall bitmap for a character class, meaning
1804        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1805        be recognized. This bug has been fixed.
1806    
1807     7. Patches from the folks at Google:
1808    
1809          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1810          real life, but is still worth protecting against".
1811    
1812          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1813          regular expressions".
1814    
1815          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1816          have it.
1817    
1818          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1819          "configure" and the latter not, in order to fix a problem somebody had
1820          with compiling the Arg class on HP-UX.
1821    
1822          (e) Improve the error-handling of the C++ wrapper a little bit.
1823    
1824          (f) New tests for checking recursion limiting.
1825    
1826     8. The pcre_memmove() function, which is used only if the environment does not
1827        have a standard memmove() function (and is therefore rarely compiled),
1828        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1829        returning a result (though PCRE never actually uses the result).
1830    
1831     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1832        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1833        returned instead of calling malloc() with an overflowing number that would
1834        most likely cause subsequent chaos.
1835    
1836    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1837    
1838    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1839        with this option is matched, the nmatch and pmatch options of regexec() are
1840        ignored.
1841    
1842    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1843        provided in case anyone wants to the the POSIX interface with UTF-8
1844        strings.
1845    
1846    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1847        C++ linking (needed for some HP-UX environments).
1848    
1849    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1850        (unused parameter) and in the pcre_printint() function (omitted "default"
1851        switch label when the default is to do nothing).
1852    
1853    15. Added some code to make it possible, when PCRE is compiled as a C++
1854        library, to replace subject pointers for pcre_exec() with a smart pointer
1855        class, thus making it possible to process discontinuous strings.
1856    
1857    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1858        much the same function. They were added by different people who were trying
1859        to make PCRE easy to compile on non-Unix systems. It has been suggested
1860        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1861        for compiling on Windows systems. I have therefore replaced it with
1862        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1863        defaults to "extern" for C or "extern C" for C++, which works fine on
1864        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1865        SCOPE with something explicit in config.h. In addition:
1866    
1867        (a) pcreposix.h still had just "extern" instead of either of these macros;
1868            I have replaced it with PCRE_DATA_SCOPE.
1869    
1870        (b) Functions such as _pcre_xclass(), which are internal to the library,
1871            but external in the C sense, all had PCRE_EXPORT in their definitions.
1872            This is apparently wrong for the Windows case, so I have removed it.
1873            (It makes no difference on Unix-like systems.)
1874    
1875    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1876        of recursive calls to match(). This is different to MATCH_LIMIT because
1877        that limits the total number of calls to match(), not all of which increase
1878        the depth of recursion. Limiting the recursion depth limits the amount of
1879        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1880        when PCRE is compiled, and changed at run time. A patch from Google adds
1881        this functionality to the C++ interface.
1882    
1883    18. Changes to the handling of Unicode character properties:
1884    
1885        (a) Updated the table to Unicode 4.1.0.
1886    
1887        (b) Recognize characters that are not in the table as "Cn" (undefined).
1888    
1889        (c) I revised the way the table is implemented to a much improved format
1890            which includes recognition of ranges. It now supports the ranges that
1891            are defined in UnicodeData.txt, and it also amalgamates other
1892            characters into ranges. This has reduced the number of entries in the
1893            table from around 16,000 to around 3,000, thus reducing its size
1894            considerably. I realized I did not need to use a tree structure after
1895            all - a binary chop search is just as efficient. Having reduced the
1896            number of entries, I extended their size from 6 bytes to 8 bytes to
1897            allow for more data.
1898    
1899        (d) Added support for Unicode script names via properties such as \p{Han}.
1900    
1901    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1902        matching that character.
1903    
1904    20. When matching a repeated Unicode property with a minimum greater than zero,
1905        (for example \pL{2,}), PCRE could look past the end of the subject if it
1906        reached it while seeking the minimum number of characters. This could
1907        happen only if some of the characters were more than one byte long, because
1908        there is a check for at least the minimum number of bytes.
1909    
1910    21. Refactored the implementation of \p and \P so as to be more general, to
1911        allow for more different types of property in future. This has changed the
1912        compiled form incompatibly. Anybody with saved compiled patterns that use
1913        \p or \P will have to recompile them.
1914    
1915    22. Added "Any" and "L&" to the supported property types.
1916    
1917    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1918        but give a compile time error if the value is greater than 0xff.
1919    
1920    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1921        accidentally not being installed or uninstalled.
1922    
1923    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1924        made were to insert the current release number. This seemed silly, because
1925        it made things harder for people building PCRE on systems that don't run
1926        "configure". I have turned pcre.h into a distributed file, no longer built
1927        by "configure", with the version identification directly included. There is
1928        no longer a pcre.h.in file.
1929    
1930        However, this change necessitated a change to the pcre-config script as
1931        well. It is built from pcre-config.in, and one of the substitutions was the
1932        release number. I have updated configure.ac so that ./configure now finds
1933        the release number by grepping pcre.h.
1934    
1935    26. Added the ability to run the tests under valgrind.
1936    
1937    
1938    Version 6.4 05-Sep-05
1939    ---------------------
1940    
1941     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1942        "--" to be printed when multiple files were scanned, even when none of the
1943        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1944        consider it to be a bug, and have restored the previous behaviour.
1945    
1946     2. A couple of code tidies to get rid of compiler warnings.
1947    
1948     3. The pcretest program used to cheat by referring to symbols in the library
1949        whose names begin with _pcre_. These are internal symbols that are not
1950        really supposed to be visible externally, and in some environments it is
1951        possible to suppress them. The cheating is now confined to including
1952        certain files from the library's source, which is a bit cleaner.
1953    
1954     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1955        file's purpose clearer.
1956    
1957     5. Reorganized pcre_ucp_findchar().
1958    
1959    
1960    Version 6.3 15-Aug-05
1961    ---------------------
1962    
1963     1. The file libpcre.pc.in did not have general read permission in the tarball.
1964    
1965     2. There were some problems when building without C++ support:
1966    
1967        (a) If C++ support was not built, "make install" and "make test" still
1968            tried to test it.
1969    
1970        (b) There were problems when the value of CXX was explicitly set. Some
1971            changes have been made to try to fix these, and ...
1972    
1973        (c) --disable-cpp can now be used to explicitly disable C++ support.
1974    
1975        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1976            backslash in a target when C++ was disabled. This confuses some
1977            versions of "make", apparently. Using an intermediate variable solves
1978            this. (Same for CPP_LOBJ.)
1979    
1980     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1981        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1982        necessary on certain architectures.
1983    
1984     4. Added a setting of -export-symbols-regex to the link command to remove
1985        those symbols that are exported in the C sense, but actually are local
1986        within the library, and not documented. Their names all begin with
1987        "_pcre_". This is not a perfect job, because (a) we have to except some
1988        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1989        available (and never for static libraries). I have made a note to try to
1990        find a way round (a) in the future.
1991    
1992    
1993    Version 6.2 01-Aug-05
1994    ---------------------
1995    
1996     1. There was no test for integer overflow of quantifier values. A construction
1997        such as {1111111111111111} would give undefined results. What is worse, if
1998        a minimum quantifier for a parenthesized subpattern overflowed and became
1999        negative, the calculation of the memory size went wrong. This could have
2000        led to memory overwriting.
2001    
2002     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2003    
2004     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2005        operating environments where this matters.
2006    
2007     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2008        PCRE options from within the C++ wrapper.
2009    
2010     5. Named capturing subpatterns were not being correctly counted when a pattern
2011        was compiled. This caused two problems: (a) If there were more than 100
2012        such subpatterns, the calculation of the memory needed for the whole
2013        compiled pattern went wrong, leading to an overflow error. (b) Numerical
2014        back references of the form \12, where the number was greater than 9, were
2015        not recognized as back references, even though there were sufficient
2016        previous subpatterns.
2017    
2018     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2019        versions of gcc, e.g. 2.95.4.
2020    
2021    
2022  Version 6.1 21-Jun-05  Version 6.1 21-Jun-05
2023  ---------------------  ---------------------
2024    

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