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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
2023    ---------------------
2024    
2025     1. There was one reference to the variable "posix" in pcretest.c that was not
2026        surrounded by "#if !defined NOPOSIX".
2027    
2028     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2029        the cross-check on the old pcre_info() function, for the benefit of the
2030        cut-down version of PCRE that is currently imported into Exim.
2031    
2032     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2033        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2034        patterns that start (?i) but I don't think that matters. The use of (?i) is
2035        just an example; this all applies to the other options as well.
2036    
2037     4. Since libtool seems to echo the compile commands it is issuing, the output
2038        from "make" can be reduced a bit by putting "@" in front of each libtool
2039        compile command.
2040    
2041     5. Patch from the folks at Google for configure.in to be a bit more thorough
2042        in checking for a suitable C++ installation before trying to compile the
2043        C++ stuff. This should fix a reported problem when a compiler was present,
2044        but no suitable headers.
2045    
2046     6. The man pages all had just "PCRE" as their title. I have changed them to
2047        be the relevant file name. I have also arranged that these names are
2048        retained in the file doc/pcre.txt, which is a concatenation in text format
2049        of all the man pages except the little individual ones for each function.
2050    
2051     7. The NON-UNIX-USE file had not been updated for the different set of source
2052        files that come with release 6. I also added a few comments about the C++
2053        wrapper.
2054    
2055    
2056    Version 6.0 07-Jun-05
2057    ---------------------
2058    
2059     1. Some minor internal re-organization to help with my DFA experiments.
2060    
2061     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2062        didn't matter for the library itself when fully configured, but did matter
2063        when compiling without UCP support, or within Exim, where the ucp files are
2064        not imported.
2065    
2066     3. Refactoring of the library code to split up the various functions into
2067        different source modules. The addition of the new DFA matching code (see
2068        below) to a single monolithic source would have made it really too
2069        unwieldy, quite apart from causing all the code to be include in a
2070        statically linked application, when only some functions are used. This is
2071        relevant even without the DFA addition now that patterns can be compiled in
2072        one application and matched in another.
2073    
2074        The downside of splitting up is that there have to be some external
2075        functions and data tables that are used internally in different modules of
2076        the library but which are not part of the API. These have all had their
2077        names changed to start with "_pcre_" so that they are unlikely to clash
2078        with other external names.
2079    
2080     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2081        a different (DFA) algorithm. Although it is slower than the original
2082        function, it does have some advantages for certain types of matching
2083        problem.
2084    
2085     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2086        including restarting after a partial match.
2087    
2088     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2089        defined when compiling for Windows was sent to me. I have put it into the
2090        code, though I have no means of testing or verifying it.
2091    
2092     7. Added the pcre_refcount() auxiliary function.
2093    
2094     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2095        match before or at the first newline in the subject string. In pcretest,
2096        the /f option on a pattern can be used to set this.
2097    
2098     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2099        would behave wrongly. This has been present in PCRE since release 4.0.
2100    
2101    10. A number of changes to the pcregrep command:
2102    
2103        (a) Refactored how -x works; insert ^(...)$ instead of setting
2104            PCRE_ANCHORED and checking the length, in preparation for adding
2105            something similar for -w.
2106    
2107        (b) Added the -w (match as a word) option.
2108    
2109        (c) Refactored the way lines are read and buffered so as to have more
2110            than one at a time available.
2111    
2112        (d) Implemented a pcregrep test script.
2113    
2114        (e) Added the -M (multiline match) option. This allows patterns to match
2115            over several lines of the subject. The buffering ensures that at least
2116            8K, or the rest of the document (whichever is the shorter) is available
2117            for matching (and similarly the previous 8K for lookbehind assertions).
2118    
2119        (f) Changed the --help output so that it now says
2120    
2121              -w, --word-regex(p)
2122    
2123            instead of two lines, one with "regex" and the other with "regexp"
2124            because that confused at least one person since the short forms are the
2125            same. (This required a bit of code, as the output is generated
2126            automatically from a table. It wasn't just a text change.)
2127    
2128        (g) -- can be used to terminate pcregrep options if the next thing isn't an
2129            option but starts with a hyphen. Could be a pattern or a path name
2130            starting with a hyphen, for instance.
2131    
2132        (h) "-" can be given as a file name to represent stdin.
2133    
2134        (i) When file names are being printed, "(standard input)" is used for
2135            the standard input, for compatibility with GNU grep. Previously
2136            "<stdin>" was used.
2137    
2138        (j) The option --label=xxx can be used to supply a name to be used for
2139            stdin when file names are being printed. There is no short form.
2140    
2141        (k) Re-factored the options decoding logic because we are going to add
2142            two more options that take data. Such options can now be given in four
2143            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2144    
2145        (l) Added the -A, -B, and -C options for requesting that lines of context
2146            around matches be printed.
2147    
2148        (m) Added the -L option to print the names of files that do not contain
2149            any matching lines, that is, the complement of -l.
2150    
2151        (n) The return code is 2 if any file cannot be opened, but pcregrep does
2152            continue to scan other files.
2153    
2154        (o) The -s option was incorrectly implemented. For compatibility with other
2155            greps, it now suppresses the error message for a non-existent or non-
2156            accessible file (but not the return code). There is a new option called
2157            -q that suppresses the output of matching lines, which was what -s was
2158            previously doing.
2159    
2160        (p) Added --include and --exclude options to specify files for inclusion
2161            and exclusion when recursing.
2162    
2163    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2164        Hopefully, it now does.
2165    
2166    12. Missing cast in pcre_study().
2167    
2168    13. Added an "uninstall" target to the makefile.
2169    
2170    14. Replaced "extern" in the function prototypes in Makefile.in with
2171        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2172        world, but is set differently for Windows.
2173    
2174    15. Added a second compiling function called pcre_compile2(). The only
2175        difference is that it has an extra argument, which is a pointer to an
2176        integer error code. When there is a compile-time failure, this is set
2177        non-zero, in addition to the error test pointer being set to point to an
2178        error message. The new argument may be NULL if no error number is required
2179        (but then you may as well call pcre_compile(), which is now just a
2180        wrapper). This facility is provided because some applications need a
2181        numeric error indication, but it has also enabled me to tidy up the way
2182        compile-time errors are handled in the POSIX wrapper.
2183    
2184    16. Added VPATH=.libs to the makefile; this should help when building with one
2185        prefix path and installing with another. (Or so I'm told by someone who
2186        knows more about this stuff than I do.)
2187    
2188    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2189        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2190        match everything, including newlines. This is not POSIX-compatible, but
2191        somebody wanted the feature. From pcretest it can be activated by using
2192        both the P and the s flags.
2193    
2194    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2195    
2196    19. libpcre.pc was being incorrectly installed as executable.
2197    
2198    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2199        it now also looks for '\r' so that it will work unmodified on Windows.
2200    
2201    21. Added Google's contributed C++ wrapper to the distribution.
2202    
2203    22. Added some untidy missing memory free() calls in pcretest, to keep
2204        Electric Fence happy when testing.
2205    
2206    
2207    
2208    Version 5.0 13-Sep-04
2209    ---------------------
2210    
2211     1. Internal change: literal characters are no longer packed up into items
2212        containing multiple characters in a single byte-string. Each character
2213        is now matched using a separate opcode. However, there may be more than one
2214        byte in the character in UTF-8 mode.
2215    
2216     2. The pcre_callout_block structure has two new fields: pattern_position and
2217        next_item_length. These contain the offset in the pattern to the next match
2218        item, and its length, respectively.
2219    
2220     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2221        insertion of callouts before each pattern item. Added the /C option to
2222        pcretest to make use of this.
2223    
2224     4. On the advice of a Windows user, the lines
2225    
2226          #if defined(_WIN32) || defined(WIN32)
2227          _setmode( _fileno( stdout ), 0x8000 );
2228          #endif  /* defined(_WIN32) || defined(WIN32) */
2229    
2230        have been added to the source of pcretest. This apparently does useful
2231        magic in relation to line terminators.
2232    
2233     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2234        for the benefit of those environments where the "b" makes a difference.
2235    
2236     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2237        to know about it. I have put a hack into configure.in that adds in code
2238        to set GCC=yes if CC=icc. This seems to end up at a point in the
2239        generated configure script that is early enough to affect the setting of
2240        compiler options, which is what is needed, but I have no means of testing
2241        whether it really works. (The user who reported this had patched the
2242        generated configure script, which of course I cannot do.)
2243    
2244        LATER: After change 22 below (new libtool files), the configure script
2245        seems to know about icc (and also ecc). Therefore, I have commented out
2246        this hack in configure.in.
2247    
2248     7. Added support for pkg-config (2 patches were sent in).
2249    
2250     8. Negated POSIX character classes that used a combination of internal tables
2251        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2252        [[:^ascii]]. Typically, they would match almost any characters. The other
2253        POSIX classes were not broken in this way.
2254    
2255     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2256        to find the match, as PCRE was deluded into thinking that the match had to
2257        start at the start point or following a newline. The same bug applied to
2258        patterns with negative forward assertions or any backward assertions
2259        preceding ".*" at the start, unless the pattern required a fixed first
2260        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2261    
2262    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2263        starting at the last subject character, bytes beyond the end of the subject
2264        string were read.
2265    
2266    11. Renamed the variable "class" as "classbits" to make life easier for C++
2267        users. (Previously there was a macro definition, but it apparently wasn't
2268        enough.)
2269    
2270    12. Added the new field "tables" to the extra data so that tables can be passed
2271        in at exec time, or the internal tables can be re-selected. This allows
2272        a compiled regex to be saved and re-used at a later time by a different
2273        program that might have everything at different addresses.
2274    
2275    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2276        -R library as well as a -L library.
2277    
2278    14. The debugging options of pcretest (-d on the command line or D on a
2279        pattern) showed incorrect output for anything following an extended class
2280        that contained multibyte characters and which was followed by a quantifier.
2281    
2282    15. Added optional support for general category Unicode character properties
2283        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2284        support. It adds about 90K to the size of the library. The meanings of the
2285        inbuilt class escapes such as \d and \s have NOT been changed.
2286    
2287    16. Updated pcredemo.c to include calls to free() to release the memory for the
2288        compiled pattern.
2289    
2290    17. The generated file chartables.c was being created in the source directory
2291        instead of in the building directory. This caused the build to fail if the
2292        source directory was different from the building directory, and was
2293        read-only.
2294    
2295    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2296        file. No doubt somebody will tell me if they don't make sense... Also added
2297        Dan Mooney's comments about building on OpenVMS.
2298    
2299    19. Added support for partial matching via the PCRE_PARTIAL option for
2300        pcre_exec() and the \P data escape in pcretest.
2301    
2302    20. Extended pcretest with 3 new pattern features:
2303    
2304        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2305              write the compiled pattern to the file whose name is "rest-of-line".
2306              This is a straight binary dump of the data, with the saved pointer to
2307              the character tables forced to be NULL. The study data, if any, is
2308              written too. After writing, pcretest reads a new pattern.
2309    
2310        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2311              compiled pattern from the given file. There must not be any
2312              occurrences of "<" in the file name (pretty unlikely); if there are,
2313              pcretest will instead treat the initial "<" as a pattern delimiter.
2314              After reading in the pattern, pcretest goes on to read data lines as
2315              usual.
2316    
2317        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2318              and 16-bit fields in a compiled pattern, to simulate a pattern that
2319              was compiled on a host of opposite endianness.
2320    
2321    21. The pcre-exec() function can now cope with patterns that were compiled on
2322        hosts of opposite endianness, with this restriction:
2323    
2324          As for any compiled expression that is saved and used later, the tables
2325          pointer field cannot be preserved; the extra_data field in the arguments
2326          to pcre_exec() should be used to pass in a tables address if a value
2327          other than the default internal tables were used at compile time.
2328    
2329    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2330        now diagnosed as an error. Previously, most of the time, a negative number
2331        would have been treated as zero, but if in addition "ovector" was passed as
2332        NULL, a crash could occur.
2333    
2334    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2335        new versions from the libtool 1.5 distribution (the last one is a copy of
2336        a file called libtool.m4). This seems to have fixed the need to patch
2337        "configure" to support Darwin 1.3 (which I used to do). However, I still
2338        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2339        workstation).
2340    
2341    24. Changed the PCRE licence to be the more standard "BSD" licence.
2342    
2343    
2344    Version 4.5 01-Dec-03
2345    ---------------------
2346    
2347     1. There has been some re-arrangement of the code for the match() function so
2348        that it can be compiled in a version that does not call itself recursively.
2349        Instead, it keeps those local variables that need separate instances for
2350        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2351        needs to "recurse". Keeping track of where control must go is done by means
2352        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2353        hide most of the details from the main code, and operates only if
2354        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2355        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2356        operating.
2357    
2358        To make it easier for callers to provide specially tailored get/free
2359        functions for this usage, two new functions, pcre_stack_malloc, and
2360        pcre_stack_free, are used. They are always called in strict stacking order,
2361        and the size of block requested is always the same.
2362    
2363        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2364        PCRE has been compiled to use the stack or the heap for recursion. The
2365        -C option of pcretest uses this to show which version is compiled.
2366    
2367        A new data escape \S, is added to pcretest; it causes the amounts of store
2368        obtained and freed by both kinds of malloc/free at match time to be added
2369        to the output.
2370    
2371     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2372        what's available on my current Linux desktop machine.
2373    
2374     3. When matching a UTF-8 string, the test for a valid string at the start has
2375        been extended. If start_offset is not zero, PCRE now checks that it points
2376        to a byte that is the start of a UTF-8 character. If not, it returns
2377        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2378        this is necessary because there may be backward assertions in the pattern.
2379        When matching the same subject several times, it may save resources to use
2380        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2381    
2382     4. The code for checking the validity of UTF-8 strings has been tightened so
2383        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2384        containing "overlong sequences".
2385    
2386     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2387        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2388        should have been "&", but it just so happened that all the cases this let
2389        through by mistake were picked up later in the function.
2390    
2391     6. I had used a variable called "isblank" - this is a C99 function, causing
2392        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2393    
2394     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2395        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2396        so the version is shown; (c) stop "make test" echoing "./RunTest".
2397    
2398     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2399    
2400     9. The prototype for memmove() for systems that don't have it was using
2401        size_t, but the inclusion of the header that defines size_t was later. I've
2402        moved the #includes for the C headers earlier to avoid this.
2403    
2404    10. Added some adjustments to the code to make it easier to compiler on certain
2405        special systems:
2406    
2407          (a) Some "const" qualifiers were missing.
2408          (b) Added the macro EXPORT before all exported functions; by default this
2409              is defined to be empty.
2410          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2411              that it reads its output file name as an argument instead of writing
2412              to the standard output and assuming this can be redirected.
2413    
2414    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2415        class containing characters with values greater than 255, PCRE compilation
2416        went into a loop.
2417    
2418    12. A recursive reference to a subpattern that was within another subpattern
2419        that had a minimum quantifier of zero caused PCRE to crash. For example,
2420        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2421        recursion. If the recursively-called subpattern itself had a zero repeat,
2422        that was OK.
2423    
2424    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2425        buffer into which it was copied (for escape processing) was still set at
2426        1024, so long lines caused crashes.
2427    
2428    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2429        "internal error: code overflow...". This applied to any character class
2430        that was followed by a possessive quantifier.
2431    
2432    15. Modified the Makefile to add libpcre.la as a prerequisite for
2433        libpcreposix.la because I was told this is needed for a parallel build to
2434        work.
2435    
2436    16. If a pattern that contained .* following optional items at the start was
2437        studied, the wrong optimizing data was generated, leading to matching
2438        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2439        matching string must start with a or b or c. The correct conclusion for
2440        this pattern is that a match can start with any character.
2441    
2442    
2443    Version 4.4 13-Aug-03
2444    ---------------------
2445    
2446     1. In UTF-8 mode, a character class containing characters with values between
2447        127 and 255 was not handled correctly if the compiled pattern was studied.
2448        In fixing this, I have also improved the studying algorithm for such
2449        classes (slightly).
2450    
2451     2. Three internal functions had redundant arguments passed to them. Removal
2452        might give a very teeny performance improvement.
2453    
2454     3. Documentation bug: the value of the capture_top field in a callout is *one
2455        more than* the number of the hightest numbered captured substring.
2456    
2457     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2458        in incorrectly linking with a previously installed version. They now link
2459        explicitly with libpcre.la.
2460    
2461     5. configure.in no longer needs to recognize Cygwin specially.
2462    
2463     6. A problem in pcre.in for Windows platforms is fixed.
2464    
2465     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2466        pcretest, it used to include the size of the study block as part of its
2467        output. Unfortunately, the structure contains a field that has a different
2468        size on different hardware architectures. This meant that the tests that
2469        showed this size failed. As the block is currently always of a fixed size,
2470        this information isn't actually particularly useful in pcretest output, so
2471        I have just removed it.
2472    
2473     8. Three pre-processor statements accidentally did not start in column 1.
2474        Sadly, there are *still* compilers around that complain, even though
2475        standard C has not required this for well over a decade. Sigh.
2476    
2477     9. In pcretest, the code for checking callouts passed small integers in the
2478        callout_data field, which is a void * field. However, some picky compilers
2479        complained about the casts involved for this on 64-bit systems. Now
2480        pcretest passes the address of the small integer instead, which should get
2481        rid of the warnings.
2482    
2483    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2484        both compile and run time, and gives an error if an invalid UTF-8 sequence
2485        is found. There is a option for disabling this check in cases where the
2486        string is known to be correct and/or the maximum performance is wanted.
2487    
2488    11. In response to a bug report, I changed one line in Makefile.in from
2489    
2490            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2491        to
2492            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2493    
2494        to look similar to other lines, but I have no way of telling whether this
2495        is the right thing to do, as I do not use Windows. No doubt I'll get told
2496        if it's wrong...
2497    
2498    
2499    Version 4.3 21-May-03
2500    ---------------------
2501    
2502    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2503       Makefile.
2504    
2505    2. Some refactoring to improve the quality of the code:
2506    
2507       (i)   The utf8_table... variables are now declared "const".
2508    
2509       (ii)  The code for \cx, which used the "case flipping" table to upper case
2510             lower case letters, now just substracts 32. This is ASCII-specific,
2511             but the whole concept of \cx is ASCII-specific, so it seems
2512             reasonable.
2513    
2514       (iii) PCRE was using its character types table to recognize decimal and
2515             hexadecimal digits in the pattern. This is silly, because it handles
2516             only 0-9, a-f, and A-F, but the character types table is locale-
2517             specific, which means strange things might happen. A private
2518             table is now used for this - though it costs 256 bytes, a table is
2519             much faster than multiple explicit tests. Of course, the standard
2520             character types table is still used for matching digits in subject
2521             strings against \d.
2522    
2523       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2524             ending in _t are). So I've renamed it as ESC_tee.
2525    
2526    3. The first argument for regexec() in the POSIX wrapper should have been
2527       defined as "const".
2528    
2529    4. Changed pcretest to use malloc() for its buffers so that they can be
2530       Electric Fenced for debugging.
2531    
2532    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2533       to read one or more bytes before the start of the subject string. Often this
2534       had no effect on PCRE's behaviour, but in some circumstances it could
2535       provoke a segmentation fault.
2536    
2537    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2538       to try to read one or more bytes before the start of the subject string.
2539    
2540    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2541       UTF-8 support could misbehave in various ways if the subject string
2542       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2543       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2544       back over UTF-8 characters.)
2545    
2546    
2547    Version 4.2 14-Apr-03
2548    ---------------------
2549    
2550    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2551    
2552    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2553         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2554         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2555         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2556         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2557           and BUILD_EXEEXT
2558         Note: automatic setting of the BUILD variables is not yet working
2559         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2560           compile-time but not at link-time
2561         [LINK]: use for linking executables only
2562         make different versions for Windows and non-Windows
2563         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2564           libraries
2565         [LINK_FOR_BUILD]: new variable
2566         [OBJEXT]: use throughout
2567         [EXEEXT]: use throughout
2568         <winshared>: new target
2569         <wininstall>: new target
2570         <dftables.o>: use native compiler
2571         <dftables>: use native linker
2572         <install>: handle Windows platform correctly
2573         <clean>: ditto
2574         <check>: ditto
2575         copy DLL to top builddir before testing
2576    
2577       As part of these changes, -no-undefined was removed again. This was reported
2578       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2579       in any case.
2580    
2581    3. Some tidies to get rid of compiler warnings:
2582    
2583       . In the match_data structure, match_limit was an unsigned long int, whereas
2584         match_call_count was an int. I've made them both unsigned long ints.
2585    
2586       . In pcretest the fact that a const uschar * doesn't automatically cast to
2587         a void * provoked a warning.
2588    
2589       . Turning on some more compiler warnings threw up some "shadow" variables
2590         and a few more missing casts.
2591    
2592    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2593       option, a class that contained a single character with a value between 128
2594       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2595    
2596    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2597       option, a class that contained several characters, but with at least one
2598       whose value was between 128 and 255 caused PCRE to crash.
2599    
2600    
2601    Version 4.1 12-Mar-03
2602    ---------------------
2603    
2604    1. Compiling with gcc -pedantic found a couple of places where casts were
2605    needed, and a string in dftables.c that was longer than standard compilers are
2606    required to support.
2607    
2608    2. Compiling with Sun's compiler found a few more places where the code could
2609    be tidied up in order to avoid warnings.
2610    
2611    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2612    first of these names is deprecated in the latest Autoconf in favour of the name
2613    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2614    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2615    analogy I have changed it to CFLAGS_FOR_BUILD.
2616    
2617    4. Added -no-undefined to the linking command in the Makefile, because this is
2618    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2619    linking step for the pcreposix library.
2620    
2621    5. PCRE was failing to diagnose the case of two named groups with the same
2622    name.
2623    
2624    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2625    literal character that is needed in the subject for a match, and scans along to
2626    ensure that it is present before embarking on the full matching process. This
2627    saves time in cases of nested unlimited repeats that are never going to match.
2628    Problem: the scan can take a lot of time if the subject is very long (e.g.
2629    megabytes), thus penalizing straightforward matches. It is now done only if the
2630    amount of subject to be scanned is less than 1000 bytes.
2631    
2632    7. A lesser problem with the same optimization is that it was recording the
2633    first character of an anchored pattern as "needed", thus provoking a search
2634    right along the subject, even when the first match of the pattern was going to
2635    fail. The "needed" character is now not set for anchored patterns, unless it
2636    follows something in the pattern that is of non-fixed length. Thus, it still
2637    fulfils its original purpose of finding quick non-matches in cases of nested
2638    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2639    
2640    
2641    Version 4.0 17-Feb-03
2642    ---------------------
2643    
2644    1. If a comment in an extended regex that started immediately after a meta-item
2645    extended to the end of string, PCRE compiled incorrect data. This could lead to
2646    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2647    
2648    2. Moved to autoconf 2.53 and libtool 1.4.2.
2649    
2650    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2651    the special perltest8 script is no longer needed - all the tests can be run
2652    from a single perltest script.
2653    
2654    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2655    by \s. It has now been removed in PCRE. This means it isn't recognized as
2656    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2657    class [:space:] *does* include VT, thereby creating a mess.
2658    
2659    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2660    space and tab.
2661    
2662    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2663    its new features into the main test script, reducing the number of scripts.
2664    
2665    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2666    were backward compatible, and made the (?i) apply to the whole pattern, as if
2667    /i were given. Now it behaves more logically, and applies the option setting
2668    only to what follows. PCRE has been changed to follow suit. However, if it
2669    finds options settings right at the start of the pattern, it extracts them into
2670    the global options, as before. Thus, they show up in the info data.
2671    
2672    8. Added support for the \Q...\E escape sequence. Characters in between are
2673    treated as literals. This is slightly different from Perl in that $ and @ are
2674    also handled as literals inside the quotes. In Perl, they will cause variable
2675    interpolation. Note the following examples:
2676    
2677        Pattern            PCRE matches      Perl matches
2678    
2679        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
2680        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
2681        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
2682    
2683    For compatibility with Perl, \Q...\E sequences are recognized inside character
2684    classes as well as outside them.
2685    
2686    9. Re-organized 3 code statements in pcretest to avoid "overflow in
2687    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2688    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2689    signed/unsigned warnings.
2690    
2691    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2692    option for pcretest, so I've replaced it by a simple function that does just
2693    that job.
2694    
2695    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2696    "pcregrep -".
2697    
2698    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2699    Java package. This provides some syntactic sugar for simple cases of what my
2700    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2701    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2702    item, you can use this simplified notation. Note that only makes sense with
2703    greedy quantifiers. Consequently, the use of the possessive quantifier forces
2704    greediness, whatever the setting of the PCRE_UNGREEDY option.
2705    
2706    13. A change of greediness default within a pattern was not taking effect at
2707    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2708    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2709    was abstracted outside.
2710    
2711    14. PCRE now supports the \G assertion. It is true when the current matching
2712    position is at the start point of the match. This differs from \A when the
2713    starting offset is non-zero. Used with the /g option of pcretest (or similar
2714    code), it works in the same way as it does for Perl's /g option. If all
2715    alternatives of a regex begin with \G, the expression is anchored to the start
2716    match position, and the "anchored" flag is set in the compiled expression.
2717    
2718    15. Some bugs concerning the handling of certain option changes within patterns
2719    have been fixed. These applied to options other than (?ims). For example,
2720    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2721    been the other way round. Some of this was related to change 7 above.
2722    
2723    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2724    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2725    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2726    POSIX classes only within a class (e.g. /[[:alpha:]]/).
2727    
2728    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2729    mode. Unlike ".", it always matches newline, whatever the setting of
2730    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2731    assertions. Perl allows it, but it doesn't (in general) work because it can't
2732    calculate the length of the lookbehind. At least, that's the case for Perl
2733    5.8.0 - I've been told they are going to document that it doesn't work in
2734    future.
2735    
2736    18. Added an error diagnosis for escapes that PCRE does not support: these are
2737    \L, \l, \N, \P, \p, \U, \u, and \X.
2738    
2739    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2740    reading past the end of the pattern in cases such as /[abcd/.
2741    
2742    20. PCRE was getting more memory than necessary for patterns with classes that
2743    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2744    
2745    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2746    compiling PCRE for use with Virtual Pascal.
2747    
2748    22. Small fix to the Makefile to make it work properly if the build is done
2749    outside the source tree.
2750    
2751    23. Added a new extension: a condition to go with recursion. If a conditional
2752    subpattern starts with (?(R) the "true" branch is used if recursion has
2753    happened, whereas the "false" branch is used only at the top level.
2754    
2755    24. When there was a very long string of literal characters (over 255 bytes
2756    without UTF support, over 250 bytes with UTF support), the computation of how
2757    much memory was required could be incorrect, leading to segfaults or other
2758    strange effects.
2759    
2760    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2761    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2762    there was a subsequent back reference to those brackets. This meant that, for
2763    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2764    possible to check for precisely this case. All we can do is abandon the
2765    optimization if .* occurs inside capturing brackets when there are any back
2766    references whatsoever. (See below for a better fix that came later.)
2767    
2768    26. The handling of the optimization for finding the first character of a
2769    non-anchored pattern, and for finding a character that is required later in the
2770    match were failing in some cases. This didn't break the matching; it just
2771    failed to optimize when it could. The way this is done has been re-implemented.
2772    
2773    27. Fixed typo in error message for invalid (?R item (it said "(?p").
2774    
2775    28. Added a new feature that provides some of the functionality that Perl
2776    provides with (?{...}). The facility is termed a "callout". The way it is done
2777    in PCRE is for the caller to provide an optional function, by setting
2778    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2779    global variable. By default it is unset, which disables all calling out. To get
2780    the function called, the regex must include (?C) at appropriate points. This
2781    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2782    This provides a means of identifying different callout points. When PCRE
2783    reaches such a point in the regex, if pcre_callout has been set, the external
2784    function is called. It is provided with data in a structure called
2785    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2786    matching continues; if it returns a non-zero value, the match at the current
2787    point fails. However, backtracking will occur if possible. [This was changed
2788    later and other features added - see item 49 below.]
2789    
2790    29. pcretest is upgraded to test the callout functionality. It provides a
2791    callout function that displays information. By default, it shows the start of
2792    the match and the current position in the text. There are some new data escapes
2793    to vary what happens:
2794    
2795        \C+         in addition, show current contents of captured substrings
2796        \C-         do not supply a callout function
2797        \C!n        return 1 when callout number n is reached
2798        \C!n!m      return 1 when callout number n is reached for the mth time
2799    
2800    30. If pcregrep was called with the -l option and just a single file name, it
2801    output "<stdin>" if a match was found, instead of the file name.
2802    
2803    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2804    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2805    pcre_exec(). This saves a malloc/free per call. The default value of
2806    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2807    when configuring.
2808    
2809    32. The default maximum size of a compiled pattern is 64K. There have been a
2810    few cases of people hitting this limit. The code now uses macros to handle the
2811    storing of links as offsets within the compiled pattern. It defaults to 2-byte
2812    links, but this can be changed to 3 or 4 bytes by --with-link-size when
2813    configuring. Tests 2 and 5 work only with 2-byte links because they output
2814    debugging information about compiled patterns.
2815    
2816    33. Internal code re-arrangements:
2817    
2818    (a) Moved the debugging function for printing out a compiled regex into
2819        its own source file (printint.c) and used #include to pull it into
2820        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2821        separate copies.
2822    
2823    (b) Defined the list of op-code names for debugging as a macro in
2824        internal.h so that it is next to the definition of the opcodes.
2825    
2826    (c) Defined a table of op-code lengths for simpler skipping along compiled
2827        code. This is again a macro in internal.h so that it is next to the
2828        definition of the opcodes.
2829    
2830    34. Added support for recursive calls to individual subpatterns, along the
2831    lines of Robin Houston's patch (but implemented somewhat differently).
2832    
2833    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2834    allow it to read and process whole directories in Win32. This code was
2835    contributed by Lionel Fourquaux; it has not been tested by me.
2836    
2837    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2838    used to name a group. Names consist of alphanumerics and underscores, and must
2839    be unique. Back references use the syntax (?P=name) and recursive calls use
2840    (?P>name) which is a PCRE extension to the Python extension. Groups still have
2841    numbers. The function pcre_fullinfo() can be used after compilation to extract
2842    a name/number map. There are three relevant calls:
2843    
2844      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
2845      PCRE_INFO_NAMECOUNT            yields the number of entries
2846      PCRE_INFO_NAMETABLE            yields a pointer to the map.
2847    
2848    The map is a vector of fixed-size entries. The size of each entry depends on
2849    the length of the longest name used. The first two bytes of each entry are the
2850    group number, most significant byte first. There follows the corresponding
2851    name, zero terminated. The names are in alphabetical order.
2852    
2853    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2854    case instead of 255. Making it the same both with and without UTF-8 support
2855    means that the same test output works with both.
2856    
2857    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2858    calling malloc() with a zero argument.
2859    
2860    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2861    optimization. I've improved things by keeping a bitmap of backreferences with
2862    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2863    fact referenced, the optimization can be applied. It is unlikely that a
2864    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2865    the match to follow \n) will appear inside brackets with a number greater than
2866    31, but if it does, any back reference > 31 suppresses the optimization.
2867    
2868    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2869    of disabling numbered capturing parentheses. Any opening parenthesis that is
2870    not followed by ? behaves as if it were followed by ?: but named parentheses
2871    can still be used for capturing (and they will acquire numbers in the usual
2872    way).
2873    
2874    41. Redesigned the return codes from the match() function into yes/no/error so
2875    that errors can be passed back from deep inside the nested calls. A malloc
2876    failure while inside a recursive subpattern call now causes the
2877    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2878    
2879    42. It is now possible to set a limit on the number of times the match()
2880    function is called in a call to pcre_exec(). This facility makes it possible to
2881    limit the amount of recursion and backtracking, though not in a directly
2882    obvious way, because the match() function is used in a number of different
2883    circumstances. The count starts from zero for each position in the subject
2884    string (for non-anchored patterns). The default limit is, for compatibility, a
2885    large number, namely 10 000 000. You can change this in two ways:
2886    
2887    (a) When configuring PCRE before making, you can use --with-match-limit=n
2888        to set a default value for the compiled library.
2889    
2890    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2891        a different value is set. See 45 below.
2892    
2893    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2894    
2895    43. Added a new function pcre_config(int, void *) to enable run-time extraction
2896    of things that can be changed at compile time. The first argument specifies
2897    what is wanted and the second points to where the information is to be placed.
2898    The current list of available information is:
2899    
2900      PCRE_CONFIG_UTF8
2901    
2902    The output is an integer that is set to one if UTF-8 support is available;
2903    otherwise it is set to zero.
2904    
2905      PCRE_CONFIG_NEWLINE
2906    
2907    The output is an integer that it set to the value of the code that is used for
2908    newline. It is either LF (10) or CR (13).
2909    
2910      PCRE_CONFIG_LINK_SIZE
2911    
2912    The output is an integer that contains the number of bytes used for internal
2913    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2914    
2915      PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2916    
2917    The output is an integer that contains the threshold above which the POSIX
2918    interface uses malloc() for output vectors. See item 31 above.
2919    
2920      PCRE_CONFIG_MATCH_LIMIT
2921    
2922    The output is an unsigned integer that contains the default limit of the number
2923    of match() calls in a pcre_exec() execution. See 42 above.
2924    
2925    44. pcretest has been upgraded by the addition of the -C option. This causes it
2926    to extract all the available output from the new pcre_config() function, and to
2927    output it. The program then exits immediately.
2928    
2929    45. A need has arisen to pass over additional data with calls to pcre_exec() in
2930    order to support additional features. One way would have been to define
2931    pcre_exec2() (for example) with extra arguments, but this would not have been
2932    extensible, and would also have required all calls to the original function to
2933    be mapped to the new one. Instead, I have chosen to extend the mechanism that
2934    is used for passing in "extra" data from pcre_study().
2935    
2936    The pcre_extra structure is now exposed and defined in pcre.h. It currently
2937    contains the following fields:
2938    
2939      flags         a bitmap indicating which of the following fields are set
2940      study_data    opaque data from pcre_study()
2941      match_limit   a way of specifying a limit on match() calls for a specific
2942                      call to pcre_exec()
2943      callout_data  data for callouts (see 49 below)
2944    
2945    The flag bits are also defined in pcre.h, and are
2946    
2947      PCRE_EXTRA_STUDY_DATA
2948      PCRE_EXTRA_MATCH_LIMIT
2949      PCRE_EXTRA_CALLOUT_DATA
2950    
2951    The pcre_study() function now returns one of these new pcre_extra blocks, with
2952    the actual study data pointed to by the study_data field, and the
2953    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2954    before. That is, this change is entirely upwards-compatible and requires no
2955    change to existing code.
2956    
2957    If you want to pass in additional data to pcre_exec(), you can either place it
2958    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2959    block.
2960    
2961    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2962    data string contains the escape sequence \M, pcretest calls pcre_exec() several
2963    times with different match limits, until it finds the minimum value needed for
2964    pcre_exec() to complete. The value is then output. This can be instructive; for
2965    most simple matches the number is quite small, but for pathological cases it
2966    gets very large very quickly.
2967    
2968    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2969    returns the size of the data block pointed to by the study_data field in a
2970    pcre_extra block, that is, the value that was passed as the argument to
2971    pcre_malloc() when PCRE was getting memory in which to place the information
2972    created by pcre_study(). The fourth argument should point to a size_t variable.
2973    pcretest has been extended so that this information is shown after a successful
2974    pcre_study() call when information about the compiled regex is being displayed.
2975    
2976    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2977    because what follows is always an absolute path. (Later: it turns out that this
2978    is more than cosmetic for MinGW, because it doesn't like empty path
2979    components.)
2980    
2981    49. Some changes have been made to the callout feature (see 28 above):
2982    
2983    (i)  A callout function now has three choices for what it returns:
2984    
2985           0  =>  success, carry on matching
2986         > 0  =>  failure at this point, but backtrack if possible
2987         < 0  =>  serious error, return this value from pcre_exec()
2988    
2989         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2990         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2991         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2992         use by callout functions. It will never be used by PCRE itself.
2993    
2994    (ii) The pcre_extra structure (see 45 above) has a void * field called
2995         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2996         pcre_callout_block structure has a field of the same name. The contents of
2997         the field passed in the pcre_extra structure are passed to the callout
2998         function in the corresponding field in the callout block. This makes it
2999         easier to use the same callout-containing regex from multiple threads. For
3000         testing, the pcretest program has a new data escape
3001    
3002           \C*n        pass the number n (may be negative) as callout_data
3003    
3004         If the callout function in pcretest receives a non-zero value as
3005         callout_data, it returns that value.
3006    
3007    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3008    there were some redundant $(CFLAGS) in commands that are now specified as
3009    $(LINK), which already includes $(CFLAGS).
3010    
3011    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3012    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3013    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3014    one-byte characters throughout. Note that case-insensitive matching applies
3015    only to characters whose values are less than 256. PCRE doesn't support the
3016    notion of cases for higher-valued characters.
3017    
3018    (i)   A character class whose characters are all within 0-255 is handled as
3019          a bit map, and the map is inverted for negative classes. Previously, a
3020          character > 255 always failed to match such a class; however it should
3021          match if the class was a negative one (e.g. [^ab]). This has been fixed.
3022    
3023    (ii)  A negated character class with a single character < 255 is coded as
3024          "not this character" (OP_NOT). This wasn't working properly when the test
3025          character was multibyte, either singly or repeated.
3026    
3027    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3028          mode, for example: \x{100}{2,3}.
3029    
3030    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3031          singly or repeated) now correctly test multibyte characters. However,
3032          PCRE doesn't recognize any characters with values greater than 255 as
3033          digits, spaces, or word characters. Such characters always match \D, \S,
3034          and \W, and never match \d, \s, or \w.
3035    
3036    (v)   Classes may now contain characters and character ranges with values
3037          greater than 255. For example: [ab\x{100}-\x{400}].
3038    
3039    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
3040          PCRE in UTF-8 mode.
3041    
3042    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3043    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3044    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3045    value.)
3046    
3047    53. The single man page has become too large. I have therefore split it up into
3048    a number of separate man pages. These also give rise to individual HTML pages;
3049    these are now put in a separate directory, and there is an index.html page that
3050    lists them all. Some hyperlinking between the pages has been installed.
3051    
3052    54. Added convenience functions for handling named capturing parentheses.
3053    
3054    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3055    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3056    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3057    are faulted.
3058    
3059    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3060    calling configure. These values are used when compiling the dftables.c program
3061    which is run to generate the source of the default character tables. They
3062    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3063    you will need to set these values.
3064    
3065    57. Updated the building process for Windows DLL, as provided by Fred Cox.
3066    
3067    
3068    Version 3.9 02-Jan-02
3069    ---------------------
3070    
3071    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3072    
3073    2. If --disable-static was given, the building process failed when trying to
3074    build pcretest and pcregrep. (For some reason it was using libtool to compile
3075    them, which is not right, as they aren't part of the library.)
3076    
3077    
3078    Version 3.8 18-Dec-01
3079    ---------------------
3080    
3081    1. The experimental UTF-8 code was completely screwed up. It was packing the
3082    bytes in the wrong order. How dumb can you get?
3083    
3084    
3085    Version 3.7 29-Oct-01
3086    ---------------------
3087    
3088    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3089    This caused pcretest, when used on the test data, to segfault. Unfortunately,
3090    this didn't happen under Solaris 8, where I normally test things.
3091    
3092    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3093    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3094    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3095    this fix an hour or so after the initial 3.7 release.)
3096    
3097    
3098    Version 3.6 23-Oct-01
3099    ---------------------
3100    
3101    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3102    offsets passed as NULL with zero offset count.
3103    
3104    2. The config.guess and config.sub files had not been updated when I moved to
3105    the latest autoconf.
3106    
3107    
3108    Version 3.5 15-Aug-01
3109    ---------------------
3110    
3111    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3112    had been forgotten.
3113    
3114    2. By using declared but undefined structures, we can avoid using "void"
3115    definitions in pcre.h while keeping the internal definitions of the structures
3116    private.
3117    
3118    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3119    user point of view, this means that both static and shared libraries are built
3120    by default, but this can be individually controlled. More of the work of
3121    handling this static/shared cases is now inside libtool instead of PCRE's make
3122    file.
3123    
3124    4. The pcretest utility is now installed along with pcregrep because it is
3125    useful for users (to test regexs) and by doing this, it automatically gets
3126    relinked by libtool. The documentation has been turned into a man page, so
3127    there are now .1, .txt, and .html versions in /doc.
3128    
3129    5. Upgrades to pcregrep:
3130       (i)   Added long-form option names like gnu grep.
3131       (ii)  Added --help to list all options with an explanatory phrase.
3132       (iii) Added -r, --recursive to recurse into sub-directories.
3133       (iv)  Added -f, --file to read patterns from a file.
3134    
3135    6. pcre_exec() was referring to its "code" argument before testing that
3136    argument for NULL (and giving an error if it was NULL).
3137    
3138    7. Upgraded Makefile.in to allow for compiling in a different directory from
3139    the source directory.
3140    
3141    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3142    options bits, the pointer it was passed was to an int instead of to an unsigned
3143    long int. This mattered only on 64-bit systems.
3144    
3145    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3146    generated) instead of pcre.in, which it its source. Also made the same change
3147    in several of the .c files.
3148    
3149    10. A new release of gcc defines printf() as a macro, which broke pcretest
3150    because it had an ifdef in the middle of a string argument for printf(). Fixed
3151    by using separate calls to printf().
3152    
3153    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3154    script, to force use of CR or LF instead of \n in the source. On non-Unix
3155    systems, the value can be set in config.h.
3156    
3157    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3158    absolute limit. Changed the text of the error message to make this clear, and
3159    likewise updated the man page.
3160    
3161    13. The limit of 99 on the number of capturing subpatterns has been removed.
3162    The new limit is 65535, which I hope will not be a "real" limit.
3163    
3164    
3165    Version 3.4 22-Aug-00
3166    ---------------------
3167    
3168    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3169    
3170    2. Diagnose condition (?(0) as an error instead of crashing on matching.
3171    
3172    
3173    Version 3.3 01-Aug-00
3174    ---------------------
3175    
3176    1. If an octal character was given, but the value was greater than \377, it
3177    was not getting masked to the least significant bits, as documented. This could
3178    lead to crashes in some systems.
3179    
3180    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3181    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3182    
3183    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3184    These just pass their arguments on to (pcre_free)(), but they are provided
3185    because some uses of PCRE bind it to non-C systems that can call its functions,
3186    but cannot call free() or pcre_free() directly.
3187    
3188    4. Add "make test" as a synonym for "make check". Corrected some comments in
3189    the Makefile.
3190    
3191    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3192    Makefile.
3193    
3194    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3195    command called pgrep for grepping around the active processes.
3196    
3197    7. Added the beginnings of support for UTF-8 character strings.
3198    
3199    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3200    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3201    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3202    out for the ar command.)
3203    
3204    
3205    Version 3.2 12-May-00
3206    ---------------------
3207    
3208    This is purely a bug fixing release.
3209    
3210    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3211    of ZA. This was just one example of several cases that could provoke this bug,
3212    which was introduced by change 9 of version 2.00. The code for breaking
3213    infinite loops after an iteration that matches an empty string was't working
3214    correctly.
3215    
3216    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3217    when matched against abbab (for example). After matching an empty string, it
3218    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3219    caused it to match further down the string than it should.
3220    
3221    3. The code contained an inclusion of sys/types.h. It isn't clear why this
3222    was there because it doesn't seem to be needed, and it causes trouble on some
3223    systems, as it is not a Standard C header. It has been removed.
3224    
3225    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3226    were reported on the Macintosh. The changes were from
3227    
3228      while ((c = *(++ptr)) != 0 && c != '\n');
3229    to
3230      while ((c = *(++ptr)) != 0 && c != '\n') ;
3231    
3232    Totally extraordinary, but if that's what it takes...
3233    
3234    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3235    available. Added HAVE_BCOPY and an autoconf test for it; if neither
3236    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3237    assumes the way PCRE uses memmove() (always moving upwards).
3238    
3239    6. PCRE is being used in one environment where strchr() is not available. There
3240    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3241    faster code anyway.
3242    
3243    
3244    Version 3.1 09-Feb-00
3245    ---------------------
3246    
3247    The only change in this release is the fixing of some bugs in Makefile.in for
3248    the "install" target:
3249    
3250    (1) It was failing to install pcreposix.h.
3251    
3252    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3253    
3254    
3255    Version 3.0 01-Feb-00
3256    ---------------------
3257    
3258    1. Add support for the /+ modifier to perltest (to output $` like it does in
3259    pcretest).
3260    
3261    2. Add support for the /g modifier to perltest.
3262    
3263    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3264    matches null strings.
3265    
3266    4. Fix perltest so that it doesn't do unwanted things when fed an empty
3267    pattern. Perl treats empty patterns specially - it reuses the most recent
3268    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3269    effect.
3270    
3271    5. The POSIX interface was broken in that it was just handing over the POSIX
3272    captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3273    required a bigger vector, with some working space on the end. This means that
3274    the POSIX wrapper now has to get and free some memory, and copy the results.
3275    
3276    6. Added some simple autoconf support, placing the test data and the
3277    documentation in separate directories, re-organizing some of the
3278    information files, and making it build pcre-config (a GNU standard). Also added
3279    libtool support for building PCRE as a shared library, which is now the
3280    default.
3281    
3282    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3283    09 are not valid octal constants. Single digits will be used for minor values
3284    less than 10.
3285    
3286    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3287    existing programs that set these in the POSIX interface can use PCRE without
3288    modification.
3289    
3290    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3291    return all that pcre_info() returns, plus additional data. The pcre_info()
3292    function is retained for compatibility, but is considered to be obsolete.
3293    
3294    10. Added experimental recursion feature (?R) to handle one common case that
3295    Perl 5.6 will be able to do with (?p{...}).
3296    
3297    11. Added support for POSIX character classes like [:alpha:], which Perl is
3298    adopting.
3299    
3300    
3301    Version 2.08 31-Aug-99
3302    ----------------------
3303    
3304    1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3305    trying to match at the startoffset position, but instead was moving forward to
3306    the next newline as if a previous match had failed.
3307    
3308    2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3309    and could get into a loop if a null string was matched other than at the start
3310    of the subject.
3311    
3312    3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3313    be distinguished at compile time, and for completeness also added PCRE_DATE.
3314    
3315    5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3316    in GnuWin32 environments.
3317    
3318    
3319    Version 2.07 29-Jul-99
3320    ----------------------
3321    
3322    1. The documentation is now supplied in plain text form and HTML as well as in
3323    the form of man page sources.
3324    
3325    2. C++ compilers don't like assigning (void *) values to other pointer types.
3326    In particular this affects malloc(). Although there is no problem in Standard
3327    C, I've put in casts to keep C++ compilers happy.
3328    
3329    3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3330    should be (const char *).
3331    
3332    4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3333    be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3334    However, I haven't made this a standard facility. The documentation doesn't
3335    mention it, and the Makefile doesn't support it.
3336    
3337    5. The Makefile now contains an "install" target, with editable destinations at
3338    the top of the file. The pcretest program is not installed.
3339    
3340    6. pgrep -V now gives the PCRE version number and date.
3341    
3342    7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3343    causing the entire string to be ignored, instead of just the last character.
3344    
3345    8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3346    non-matching string, it can take a very, very long time, even for strings of
3347    quite modest length, because of the nested recursion. PCRE now does better in
3348    some of these cases. It does this by remembering the last required literal
3349    character in the pattern, and pre-searching the subject to ensure it is present
3350    before running the real match. In other words, it applies a heuristic to detect
3351    some types of certain failure quickly, and in the above example, if presented
3352    with a string that has no trailing " it gives "no match" very quickly.
3353    
3354    9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3355    other alternatives are tried instead.
3356    
3357    
3358    Version 2.06 09-Jun-99
3359    ----------------------
3360    
3361    1. Change pcretest's output for amount of store used to show just the code
3362    space, because the remainder (the data block) varies in size between 32-bit and
3363    64-bit systems.
3364    
3365    2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3366    start matching at. This allows lookbehinds to work when searching for multiple
3367    occurrences in a string.
3368    
3369    3. Added additional options to pcretest for testing multiple occurrences:
3370    
3371       /+   outputs the rest of the string that follows a match
3372       /g   loops for multiple occurrences, using the new startoffset argument
3373       /G   loops for multiple occurrences by passing an incremented pointer
3374    
3375    4. PCRE wasn't doing the "first character" optimization for patterns starting
3376    with \b or \B, though it was doing it for other lookbehind assertions. That is,
3377    it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3378    the letter 'x'. On long subject strings, this gives a significant speed-up.
3379    
3380    
3381    Version 2.05 21-Apr-99
3382    ----------------------
3383    
3384    1. Changed the type of magic_number from int to long int so that it works
3385    properly on 16-bit systems.
3386    
3387    2. Fixed a bug which caused patterns starting with .* not to work correctly
3388    when the subject string contained newline characters. PCRE was assuming
3389    anchoring for such patterns in all cases, which is not correct because .* will
3390    not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3391    DOTALL is set at top level; otherwise it knows that patterns starting with .*
3392    must be retried after every newline in the subject.
3393    
3394    
3395    Version 2.04 18-Feb-99
3396    ----------------------
3397    
3398    1. For parenthesized subpatterns with repeats whose minimum was zero, the
3399    computation of the store needed to hold the pattern was incorrect (too large).
3400    If such patterns were nested a few deep, this could multiply and become a real
3401    problem.
3402    
3403    2. Added /M option to pcretest to show the memory requirement of a specific
3404    pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3405    
3406    3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3407    compiled in such a way that the backtracking after subsequent failure was
3408    pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3409    ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3410    
3411    
3412    Version 2.03 02-Feb-99
3413    ----------------------
3414    
3415    1. Fixed typo and small mistake in man page.
3416    
3417    2. Added 4th condition (GPL supersedes if conflict) and created separate
3418    LICENCE file containing the conditions.
3419    
3420    3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3421    Perl, that is the internal \ allows the delimiter to be included in the
3422    pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3423    the final delimiter, add \ to the end of the pattern (to test the error).
3424    
3425    4. Added the convenience functions for extracting substrings after a successful
3426    match. Updated pcretest to make it able to test these functions.
3427    
3428    
3429    Version 2.02 14-Jan-99
3430    ----------------------
3431    
3432    1. Initialized the working variables associated with each extraction so that
3433    their saving and restoring doesn't refer to uninitialized store.
3434    
3435    2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3436    compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3437    fix the problem.
3438    
3439    3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3440    calls, and wasn't printing the correct value for compiling calls. Increased the
3441    default value of LOOPREPEAT, and the number of significant figures in the
3442    times.
3443    
3444    4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3445    
3446    5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3447    a building problem on Windows NT with a FAT file system.
3448    
3449    
3450    Version 2.01 21-Oct-98
3451    ----------------------
3452    
3453    1. Changed the API for pcre_compile() to allow for the provision of a pointer
3454    to character tables built by pcre_maketables() in the current locale. If NULL
3455    is passed, the default tables are used.
3456    
3457    
3458  Version 2.00 24-Sep-98  Version 2.00 24-Sep-98
3459  ----------------------  ----------------------

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