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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.1 12-Mar-07  Version 8.13 30-Apr-2011
5    ------------------------
7    1.  The Unicode data tables have been updated to Unicode 6.0.0.
9    2.  Two minor typos in pcre_internal.h have been fixed.
11    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
15    4.  There were a number of related bugs in the code for matching backrefences
16        caselessly in UTF-8 mode when codes for the characters concerned were
17        different numbers of bytes. For example, U+023A and U+2C65 are an upper
18        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21        2-byte code at the end of the subject (it thought there wasn't enough data
22        left).
24    5.  Comprehensive information about what went wrong is now returned by
25        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26        as the output vector has at least 2 elements. The offset of the start of
27        the failing character and a reason code are placed in the vector.
29    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
30        now returned is for the first byte of the failing character, instead of the
31        last byte inspected. This is an incompatible change, but I hope it is small
32        enough not to be a problem. It makes the returned offset consistent with
33        pcre_exec() and pcre_dfa_exec().
35    7.  pcretest now gives a text phrase as well as the error number when
36        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37        failure, the offset and reason code are output.
39    8.  When \R was used with a maximizing quantifier it failed to skip backwards
40        over a \r\n pair if the subsequent match failed. Instead, it just skipped
41        back over a single character (\n). This seems wrong (because it treated the
42        two characters as a single entity when going forwards), conflicts with the
43        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45        has been changed.
47    9.  Some internal refactoring has changed the processing so that the handling
48        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49        time (the PCRE_DOTALL option was changed this way some time ago: version
50        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51        which was always a bit of a fudge. It also means that there is one less
52        argument for the match() function, which reduces its stack requirements
53        slightly. This change also fixes an incompatibility with Perl: the pattern
54        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
56    10. More internal refactoring has drastically reduced the number of recursive
57        calls to match() for possessively repeated groups such as (abc)++ when
58        using pcre_exec().
60    11. While implementing 10, a number of bugs in the handling of groups were
61        discovered and fixed:
63        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64        (a|)*(?1) gave a compile-time internal error.
65        ((a|)+)+  did not notice that the outer group could match an empty string.
66        (^a|^)+   was not marked as anchored.
67        (.*a|.*)+ was not marked as matching at start or after a newline.
69    12. Yet more internal refactoring has removed another argument from the match()
70        function. Special calls to this function are now indicated by setting a
71        value in a variable in the "match data" data block.
74    Version 8.12 15-Jan-2011
75    ------------------------
77    1.  Fixed some typos in the markup of the man pages, and wrote a script that
78        checks for such things as part of the documentation building process.
80    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
81        --match-limit and --recursion-limit options (added for 8.11). In
82        particular, this made one of the standard tests fail. (The integer value
83        went into the wrong half of a long int.)
85    3.  If the --colour option was given to pcregrep with -v (invert match), it
86        did strange things, either producing crazy output, or crashing. It should,
87        of course, ignore a request for colour when reporting lines that do not
88        match.
90    4.  Another pcregrep bug caused similar problems if --colour was specified with
91        -M (multiline) and the pattern match finished with a line ending.
93    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
94        matched in multiline mode, the following line was shown as part of the
95        match. This seems wrong, so I have changed it.
97    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
98        the check for further matches in the same line (so they could be coloured)
99        to overrun the end of the current line. If another match was found, it was
100        incorrectly shown (and then shown again when found in the next line).
102    7.  If pcregrep was compiled under Windows, there was a reference to the
103        function pcregrep_exit() before it was defined. I am assuming this was
104        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
105        reported by a user. I've moved the definition above the reference.
108    Version 8.11 10-Dec-2010
109    ------------------------
111    1.  (*THEN) was not working properly if there were untried alternatives prior
112        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
113        backtracked to try for "b" instead of moving to the next alternative branch
114        at the same level (in this case, to look for "c"). The Perl documentation
115        is clear that when (*THEN) is backtracked onto, it goes to the "next
116        alternative in the innermost enclosing group".
118    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
119        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
120        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
121        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
122        (*THEN).
124    3.  If \s appeared in a character class, it removed the VT character from
125        the class, even if it had been included by some previous item, for example
126        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
127        of \s, but is part of the POSIX "space" class.)
129    4.  A partial match never returns an empty string (because you can always
130        match an empty string at the end of the subject); however the checking for
131        an empty string was starting at the "start of match" point. This has been
132        changed to the "earliest inspected character" point, because the returned
133        data for a partial match starts at this character. This means that, for
134        example, /(?<=abc)def/ gives a partial match for the subject "abc"
135        (previously it gave "no match").
137    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
138        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
139        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
140        has an implication that the given string is incomplete (because a partial
141        match is preferred over a full match). For this reason, these items now
142        give a partial match in this situation. [Aside: previously, the one case
143        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
144        match rather than a full match, which was wrong by the old rules, but is
145        now correct.]
147    6.  There was a bug in the handling of #-introduced comments, recognized when
148        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
149        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
150        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
151        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
152        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
153        places in pcre_compile().
155    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
156        comments when looking ahead for named forward references to subpatterns,
157        the only newline sequence it recognized was NL. It now handles newlines
158        according to the set newline convention.
160    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
161        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
162        cater for a lack of strerror(). These oversights have been fixed.
164    9.  Added --match-limit and --recursion-limit to pcregrep.
166    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
168    11. When the -o option was used, pcregrep was setting a return code of 1, even
169        when matches were found, and --line-buffered was not being honoured.
171    12. Added an optional parentheses number to the -o and --only-matching options
172        of pcregrep.
174    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
175        can match an empty string. The code to do it in pcretest and pcredemo
176        needed fixing:
178        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
179            only one byte after an empty string match just before CRLF (this case
180            just got forgotten; "any" and "anycrlf" were OK).
182        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
183            mode when an empty string match preceded an ASCII character followed by
184            a non-ASCII character. (The code for advancing by one character rather
185            than one byte was nonsense.)
187        (c) The pcredemo.c sample program did not have any code at all to handle
188            the cases when CRLF is a valid newline sequence.
190    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
191        as a starting offset was within the subject string. There is now a new
192        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
193        negative or greater than the length of the string. In order to test this,
194        pcretest is extended to allow the setting of negative starting offsets.
196    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
197        starting offset points to the beginning of a UTF-8 character was
198        unnecessarily clumsy. I tidied it up.
200    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
201        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
203    17. Nobody had reported that the --include_dir option, which was added in
204        release 7.7 should have been called --include-dir (hyphen, not underscore)
205        for compatibility with GNU grep. I have changed it to --include-dir, but
206        left --include_dir as an undocumented synonym, and the same for
207        --exclude-dir, though that is not available in GNU grep, at least as of
208        release 2.5.4.
210    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
211        characters from a string of bytes) have been redefined so as not to use
212        loops, in order to improve performance in some environments. At the same
213        time, I abstracted some of the common code into auxiliary macros to save
214        repetition (this should not affect the compiled code).
216    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
217        compile-time error is now given if \c is not followed by an ASCII
218        character, that is, a byte less than 128. (In EBCDIC mode, the code is
219        different, and any byte value is allowed.)
221    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
222        START_OPTIMIZE option, which is now allowed at compile time - but just
223        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
224        to pcregrep and other applications that have no direct access to PCRE
225        options. The new /Y option in pcretest sets this option when calling
226        pcre_compile().
228    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
229        back references. Groups containing recursive back references were forced to
230        be atomic by that change, but in the case of named groups, the amount of
231        memory required was incorrectly computed, leading to "Failed: internal
232        error: code overflow". This has been fixed.
234    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
235        pcretest.c, to avoid build problems in some Borland environments.
238    Version 8.10 25-Jun-2010
239    ------------------------
241    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
242        THEN.
244    2.  (*ACCEPT) was not working when inside an atomic group.
246    3.  Inside a character class, \B is treated as a literal by default, but
247        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
248        causes the error). The code is unchanged, but I tidied the documentation.
250    4.  Inside a character class, PCRE always treated \R and \X as literals,
251        whereas Perl faults them if its -w option is set. I have changed PCRE so
252        that it faults them when PCRE_EXTRA is set.
254    5.  Added support for \N, which always matches any character other than
255        newline. (It is the same as "." when PCRE_DOTALL is not set.)
257    6.  When compiling pcregrep with newer versions of gcc which may have
258        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
259        declared with attribute warn_unused_result" were given. Just casting the
260        result to (void) does not stop the warnings; a more elaborate fudge is
261        needed. I've used a macro to implement this.
263    7.  Minor change to pcretest.c to avoid a compiler warning.
265    8.  Added four artifical Unicode properties to help with an option to make
266        \s etc use properties (see next item). The new properties are: Xan
267        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
269    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
270        use Unicode properties. (*UCP) at the start of a pattern can be used to set
271        this option. Modified pcretest to add /W to test this facility. Added
272        REG_UCP to make it available via the POSIX interface.
274    10. Added --line-buffered to pcregrep.
276    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
277        studied, and the match started with a letter with a code point greater than
278        127 whose first byte was different to the first byte of the other case of
279        the letter, the other case of this starting letter was not recognized
280        (#976).
282    12. If a pattern that was studied started with a repeated Unicode property
283        test, for example, \p{Nd}+, there was the theoretical possibility of
284        setting up an incorrect bitmap of starting bytes, but fortunately it could
285        not have actually happened in practice until change 8 above was made (it
286        added property types that matched character-matching opcodes).
288    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
289        possible starting bytes for non-anchored patterns.
291    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
292        \R, and also a number of cases that involve Unicode properties, both
293        explicit and implicit when PCRE_UCP is set.
295    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
296        input, it could crash or give wrong results if characters with values
297        greater than 0xc0 were present in the subject string. (Detail: it assumed
298        UTF-8 input when processing these items.)
300    16. Added a lot of (int) casts to avoid compiler warnings in systems where
301        size_t is 64-bit (#991).
303    17. Added a check for running out of memory when PCRE is compiled with
304        --disable-stack-for-recursion (#990).
306    18. If the last data line in a file for pcretest does not have a newline on
307        the end, a newline was missing in the output.
309    19. The default pcre_chartables.c file recognizes only ASCII characters (values
310        less than 128) in its various bitmaps. However, there is a facility for
311        generating tables according to the current locale when PCRE is compiled. It
312        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
313        characters, are recognized by isspace() and therefore were getting set in
314        these tables, and indeed these tables seem to approximate to ISO 8859. This
315        caused a problem in UTF-8 mode when pcre_study() was used to create a list
316        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
317        which of course cannot start UTF-8 characters. I have changed the code so
318        that only real ASCII characters (less than 128) and the correct starting
319        bytes for UTF-8 encodings are set for characters greater than 127 when in
320        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
321        altogether.)
323    20. Added the /T option to pcretest so as to be able to run tests with non-
324        standard character tables, thus making it possible to include the tests
325        used for 19 above in the standard set of tests.
327    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
328        reference to a subpattern the other side of a comment that contains an
329        opening parenthesis caused either an internal compiling error, or a
330        reference to the wrong subpattern.
333    Version 8.02 19-Mar-2010
334    ------------------------
336    1.  The Unicode data tables have been updated to Unicode 5.2.0.
338    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
339        configured.
341    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
342        original author of that file, following a query about its status.
344    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
345        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
347    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
348        quantifier applied to a forward-referencing subroutine call, could compile
349        incorrect code or give the error "internal error: previously-checked
350        referenced subpattern not found".
352    6.  Both MS Visual Studio and Symbian OS have problems with initializing
353        variables to point to external functions. For these systems, therefore,
354        pcre_malloc etc. are now initialized to local functions that call the
355        relevant global functions.
357    7.  There were two entries missing in the vectors called coptable and poptable
358        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
359        I've fixed the data, and added a kludgy way of testing at compile time that
360        the lengths are correct (equal to the number of opcodes).
362    8.  Following on from 7, I added a similar kludge to check the length of the
363        eint vector in pcreposix.c.
365    9.  Error texts for pcre_compile() are held as one long string to avoid too
366        much relocation at load time. To find a text, the string is searched,
367        counting zeros. There was no check for running off the end of the string,
368        which could happen if a new error number was added without updating the
369        string.
371    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
373    11. \K was not working if it appeared in an atomic group or in a group that
374        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
375        \K is "not well defined" if used in an assertion. PCRE now accepts it if
376        the assertion is positive, but not if it is negative.
378    12. Change 11 fortuitously reduced the size of the stack frame used in the
379        "match()" function of pcre_exec.c by one pointer. Forthcoming
380        implementation of support for (*MARK) will need an extra pointer on the
381        stack; I have reserved it now, so that the stack frame size does not
382        decrease.
384    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
385        item in branch that calls a recursion is a subroutine call - as in the
386        second branch in the above example - was incorrectly given the compile-
387        time error "recursive call could loop indefinitely" because pcre_compile()
388        was not correctly checking the subroutine for matching a non-empty string.
390    14. The checks for overrunning compiling workspace could trigger after an
391        overrun had occurred. This is a "should never occur" error, but it can be
392        triggered by pathological patterns such as hundreds of nested parentheses.
393        The checks now trigger 100 bytes before the end of the workspace.
395    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
398    Version 8.01 19-Jan-2010
399    ------------------------
401    1.  If a pattern contained a conditional subpattern with only one branch (in
402        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
403        computed the wrong minimum data length (which is of course zero for such
404        subpatterns). This could cause incorrect "no match" results.
406    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
407        the pattern is reset in the first branch, pcre_compile() failed with
408        "internal error: code overflow at offset...". This happened only when
409        the reset was to the original external option setting. (An optimization
410        abstracts leading options settings into an external setting, which was the
411        cause of this.)
413    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
414        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
415        assertion pattern did not match (meaning that the assertion was true), it
416        was incorrectly treated as false if the SKIP had been reached during the
417        matching. This also applied to assertions used as conditions.
419    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
420        assertion subpattern, including such a pattern used as a condition,
421        unpredictable results occurred, instead of the error return
424    5.  The C++ GlobalReplace function was not working like Perl for the special
425        situation when an empty string is matched. It now does the fancy magic
426        stuff that is necessary.
428    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
429        removed. (These were left over from very, very early versions of PCRE.)
431    7.  Some cosmetic changes to the code to make life easier when compiling it
432        as part of something else:
434        (a) Change DEBUG to PCRE_DEBUG.
436        (b) In pcre_compile(), rename the member of the "branch_chain" structure
437            called "current" as "current_branch", to prevent a collision with the
438            Linux macro when compiled as a kernel module.
440        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
441            prevent a collision with the Linux macro when compiled as a kernel
442            module.
444    8.  In pcre_compile() there are some checks for integer overflows that used to
445        cast potentially large values to (double). This has been changed to that
446        when building, a check for int64_t is made, and if it is found, it is used
447        instead, thus avoiding the use of floating point arithmetic. (There is no
448        other use of FP in PCRE.) If int64_t is not found, the fallback is to
449        double.
451    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
452        2005 (difference between two addresses compared to an unsigned value).
454    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
455        custom one, because of the following reported problem in Windows:
457          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
458              under Win32.
459          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
460              therefore missing the function definition.
461          - The compiler thus generates a "C" signature for the test function.
462          - The linker fails to find the "C" function.
463          - PCRE fails to configure if asked to do so against libbz2.
465    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
466        messages were output:
468          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
469          rerunning libtoolize, to keep the correct libtool macros in-tree.
470          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
472        I have done both of these things.
474    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
475        most of the time, it *can* run out if it is given a pattern that contains a
476        runaway infinite recursion. I updated the discussion in the pcrestack man
477        page.
479    13. Now that we have gone to the x.xx style of version numbers, the minor
480        version may start with zero. Using 08 or 09 is a bad idea because users
481        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
482        interpreted as invalid octal numbers. I've updated the previous comment in
483        configure.ac, and also added a check that gives an error if 08 or 09 are
484        used.
486    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
487        causing partial matching to fail when the end of the subject matched \W
488        in a UTF-8 pattern where \W was quantified with a minimum of 3.
490    15. There were some discrepancies between the declarations in pcre_internal.h
491        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
492        their definitions. The declarations used "const uschar *" and the
493        definitions used USPTR. Even though USPTR is normally defined as "const
494        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
495        reported that: "This difference in casting confuses some C++ compilers, for
496        example, SunCC recognizes above declarations as different functions and
497        generates broken code for hbpcre." I have changed the declarations to use
498        USPTR.
500    16. GNU libtool is named differently on some systems. The autogen.sh script now
501        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
502        (FreeBSD).
504    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
505        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
506        comment: "Figure out how to create a longlong from a string: strtoll and
507        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
508        instance, but it only takes 2 args instead of 3!"
510    18. A subtle bug concerned with back references has been fixed by a change of
511        specification, with a corresponding code fix. A pattern such as
512        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
513        refers, was giving matches when it shouldn't. For example, xa=xaaa would
514        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
515        same bug. Such groups have to be quantified to be useful, or contained
516        inside another quantified group. (If there's no repetition, the reference
517        can never match.) The problem arises because, having left the group and
518        moved on to the rest of the pattern, a later failure that backtracks into
519        the group uses the captured value from the final iteration of the group
520        rather than the correct earlier one. I have fixed this in PCRE by forcing
521        any group that contains a reference to itself to be an atomic group; that
522        is, there cannot be any backtracking into it once it has completed. This is
523        similar to recursive and subroutine calls.
526    Version 8.00 19-Oct-09
527    ----------------------
529    1.  The table for translating pcre_compile() error codes into POSIX error codes
530        was out-of-date, and there was no check on the pcre_compile() error code
531        being within the table. This could lead to an OK return being given in
532        error.
534    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
535        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
536        in a Windows environment.
538    3.  The pcregrep --count option prints the count for each file even when it is
539        zero, as does GNU grep. However, pcregrep was also printing all files when
540        --files-with-matches was added. Now, when both options are given, it prints
541        counts only for those files that have at least one match. (GNU grep just
542        prints the file name in this circumstance, but including the count seems
543        more useful - otherwise, why use --count?) Also ensured that the
544        combination -clh just lists non-zero counts, with no names.
546    4.  The long form of the pcregrep -F option was incorrectly implemented as
547        --fixed_strings instead of --fixed-strings. This is an incompatible change,
548        but it seems right to fix it, and I didn't think it was worth preserving
549        the old behaviour.
551    5.  The command line items --regex=pattern and --regexp=pattern were not
552        recognized by pcregrep, which required --regex pattern or --regexp pattern
553        (with a space rather than an '='). The man page documented the '=' forms,
554        which are compatible with GNU grep; these now work.
556    6.  No libpcreposix.pc file was created for pkg-config; there was just
557        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
559    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
560        when UCP support is not needed, by modifying the Python script that
561        generates it from Unicode data files. This should not matter if the module
562        is correctly used as a library, but I received one complaint about 50K of
563        unwanted data. My guess is that the person linked everything into his
564        program rather than using a library. Anyway, it does no harm.
566    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
567        was a minimum greater than 1 for a wide character in a possessive
568        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
569        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
570        character. Chaos in the form of incorrect output or a compiling loop could
571        result.
573    9.  The restrictions on what a pattern can contain when partial matching is
574        requested for pcre_exec() have been removed. All patterns can now be
575        partially matched by this function. In addition, if there are at least two
576        slots in the offset vector, the offset of the earliest inspected character
577        for the match and the offset of the end of the subject are set in them when
578        PCRE_ERROR_PARTIAL is returned.
580    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
581        synonymous with PCRE_PARTIAL, for backwards compatibility, and
582        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
583        and may be more useful for multi-segment matching.
585    11. Partial matching with pcre_exec() is now more intuitive. A partial match
586        used to be given if ever the end of the subject was reached; now it is
587        given only if matching could not proceed because another character was
588        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
589        string "Z", which now yields "no match" instead of "partial match". In the
590        case of pcre_dfa_exec(), "no match" is given if every matching path for the
591        final character ended with (*FAIL).
593    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
594        if the pattern had a "must contain" character that was already found in the
595        earlier partial match, unless partial matching was again requested. For
596        example, with the pattern /dog.(body)?/, the "must contain" character is
597        "g". If the first part-match was for the string "dog", restarting with
598        "sbody" failed. This bug has been fixed.
600    13. The string returned by pcre_dfa_exec() after a partial match has been
601        changed so that it starts at the first inspected character rather than the
602        first character of the match. This makes a difference only if the pattern
603        starts with a lookbehind assertion or \b or \B (\K is not supported by
604        pcre_dfa_exec()). It's an incompatible change, but it makes the two
605        matching functions compatible, and I think it's the right thing to do.
607    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
608        so that the demonstration program is easily available in environments where
609        PCRE has not been installed from source.
611    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
612        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
613        library.
615    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
616        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
617        is not the first non-POSIX option to be added. Clearly some people find
618        these options useful.
620    17. If a caller to the POSIX matching function regexec() passes a non-zero
621        value for nmatch with a NULL value for pmatch, the value of
622        nmatch is forced to zero.
624    18. RunGrepTest did not have a test for the availability of the -u option of
625        the diff command, as RunTest does. It now checks in the same way as
626        RunTest, and also checks for the -b option.
628    19. If an odd number of negated classes containing just a single character
629        interposed, within parentheses, between a forward reference to a named
630        subpattern and the definition of the subpattern, compilation crashed with
631        an internal error, complaining that it could not find the referenced
632        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
633        [The bug was that it was starting one character too far in when skipping
634        over the character class, thus treating the ] as data rather than
635        terminating the class. This meant it could skip too much.]
637    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
638        /g option in pcretest when the pattern contains \K, which makes it possible
639        to have an empty string match not at the start, even when the pattern is
640        anchored. Updated pcretest and pcredemo to use this option.
642    21. If the maximum number of capturing subpatterns in a recursion was greater
643        than the maximum at the outer level, the higher number was returned, but
644        with unset values at the outer level. The correct (outer level) value is
645        now given.
647    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
648        PCRE did not set those parentheses (unlike Perl). I have now found a way to
649        make it do so. The string so far is captured, making this feature
650        compatible with Perl.
652    23. The tests have been re-organized, adding tests 11 and 12, to make it
653        possible to check the Perl 5.10 features against Perl 5.10.
655    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
656        pattern matches a fixed length string. PCRE did not allow this; now it
657        does. Neither allows recursion.
659    25. I finally figured out how to implement a request to provide the minimum
660        length of subject string that was needed in order to match a given pattern.
661        (It was back references and recursion that I had previously got hung up
662        on.) This code has now been added to pcre_study(); it finds a lower bound
663        to the length of subject needed. It is not necessarily the greatest lower
664        bound, but using it to avoid searching strings that are too short does give
665        some useful speed-ups. The value is available to calling programs via
666        pcre_fullinfo().
668    26. While implementing 25, I discovered to my embarrassment that pcretest had
669        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
670        study optimizations had never been tested with that matching function.
671        Oops. What is worse, even when it was passed study data, there was a bug in
672        pcre_dfa_exec() that meant it never actually used it. Double oops. There
673        were also very few tests of studied patterns with pcre_dfa_exec().
675    27. If (?| is used to create subpatterns with duplicate numbers, they are now
676        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
677        on the other side of the coin, they are no longer allowed to have different
678        names, because these cannot be distinguished in PCRE, and this has caused
679        confusion. (This is a difference from Perl.)
681    28. When duplicate subpattern names are present (necessarily with different
682        numbers, as required by 27 above), and a test is made by name in a
683        conditional pattern, either for a subpattern having been matched, or for
684        recursion in such a pattern, all the associated numbered subpatterns are
685        tested, and the overall condition is true if the condition is true for any
686        one of them. This is the way Perl works, and is also more like the way
687        testing by number works.
690    Version 7.9 11-Apr-09
691    ---------------------
693    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
694        (pcretest), all targets were linked against these libraries. This included
695        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
696        libraries. This caused unwanted dependencies to be created. This problem
697        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
698        pcretest is linked with readline.
700    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
701        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
702        moved outside it again, because FALSE and TRUE are already defined in AIX,
703        but BOOL is not.
705    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
706        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
708    4.  The pcregrep documentation said spaces were inserted as well as colons (or
709        hyphens) following file names and line numbers when outputting matching
710        lines. This is not true; no spaces are inserted. I have also clarified the
711        wording for the --colour (or --color) option.
713    5.  In pcregrep, when --colour was used with -o, the list of matching strings
714        was not coloured; this is different to GNU grep, so I have changed it to be
715        the same.
717    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
718        each matching line was coloured. Now it goes on to look for further matches
719        of any of the test patterns, which is the same behaviour as GNU grep.
721    7.  A pattern that could match an empty string could cause pcregrep to loop; it
722        doesn't make sense to accept an empty string match in pcregrep, so I have
723        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
724        seems to be how GNU grep behaves.
726    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
727        start or after a newline", because the conditional assertion was not being
728        correctly handled. The rule now is that both the assertion and what follows
729        in the first alternative must satisfy the test.
731    9.  If auto-callout was enabled in a pattern with a conditional group whose
732        condition was an assertion, PCRE could crash during matching, both with
733        pcre_exec() and pcre_dfa_exec().
735    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
736        used for matching.
738    11. Unicode property support in character classes was not working for
739        characters (bytes) greater than 127 when not in UTF-8 mode.
741    12. Added the -M command line option to pcretest.
743    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
745    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
747    16. Added comments and documentation about mis-use of no_arg in the C++
748        wrapper.
750    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
751        from Martin Jerabek that uses macro names for all relevant character and
752        string constants.
754    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
755        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
756        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
757        these, but not everybody uses configure.
759    19. A conditional group that had only one branch was not being correctly
760        recognized as an item that could match an empty string. This meant that an
761        enclosing group might also not be so recognized, causing infinite looping
762        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
763        with the subject "ab", where knowledge that the repeated group can match
764        nothing is needed in order to break the loop.
766    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
767        exec(), but without supplying a callout function, matching went wrong.
769    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
770        leak if the size of the offset vector was greater than 30. When the vector
771        is smaller, the saved offsets during recursion go onto a local stack
772        vector, but for larger vectors malloc() is used. It was failing to free
773        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
774        error, in fact).
776    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
777        heapframe that is used only when UTF-8 support is enabled. This caused no
778        problem, but was untidy.
780    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
781        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
782        included within another project.
784    24. Steven Van Ingelgem's patches to add more options to the CMake support,
785        slightly modified by me:
787          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
788              not building pcregrep.
790          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
791              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
793    25. Forward references, both numeric and by name, in patterns that made use of
794        duplicate group numbers, could behave incorrectly or give incorrect errors,
795        because when scanning forward to find the reference group, PCRE was not
796        taking into account the duplicate group numbers. A pattern such as
797        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
799    26. Changed a few more instances of "const unsigned char *" to USPTR, making
800        the feature of a custom pointer more persuasive (as requested by a user).
802    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
803        pcretest.c, inside #ifndefs, because it seems they are sometimes already
804        pre-defined.
806    28. Added support for (*UTF8) at the start of a pattern.
808    29. Arrange for flags added by the "release type" setting in CMake to be shown
809        in the configuration summary.
812    Version 7.8 05-Sep-08
813    ---------------------
815    1.  Replaced UCP searching code with optimized version as implemented for Ad
816        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
817        stage table and inline lookup instead of a function, giving speed ups of 2
818        to 5 times on some simple patterns that I tested. Permission was given to
819        distribute the MultiStage2.py script that generates the tables (it's not in
820        the tarball, but is in the Subversion repository).
822    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
823        scripts.
825    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
826        a group with a zero qualifier. The result of the study could be incorrect,
827        or the function might crash, depending on the pattern.
829    4.  Caseless matching was not working for non-ASCII characters in back
830        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
831        It now works when Unicode Property Support is available.
833    5.  In pcretest, an escape such as \x{de} in the data was always generating
834        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
835        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
836        truncation.
838    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
840    7.  Added two (int) casts to pcregrep when printing the difference of two
841        pointers, in case they are 64-bit values.
843    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
844        test 2 if it fails.
846    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
847        and a #define of that name to empty if it is not externally set. This is to
848        allow users of MSVC to set it if necessary.
850    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
851        the convenience functions in the pcre_get.c source file.
853    11. An option change at the start of a pattern that had top-level alternatives
854        could cause overwriting and/or a crash. This command provoked a crash in
855        some environments:
857          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
859        This potential security problem was recorded as CVE-2008-2371.
861    12. For a pattern where the match had to start at the beginning or immediately
862        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
863        pcre_dfa_exec() could read past the end of the passed subject if there was
864        no match. To help with detecting such bugs (e.g. with valgrind), I modified
865        pcretest so that it places the subject at the end of its malloc-ed buffer.
867    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
868        exec() might read past the end of the data buffer in UTF-8 mode.
870    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
871        the data contained the byte 0x85 as part of a UTF-8 character within its
872        first line. This applied both to normal and DFA matching.
874    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
875        /^[^d]*?$/8 failed to match "abc".
877    16. Added a missing copyright notice to pcrecpp_internal.h.
879    17. Make it more clear in the documentation that values returned from
880        pcre_exec() in ovector are byte offsets, not character counts.
882    18. Tidied a few places to stop certain compilers from issuing warnings.
884    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
885        supplied by Stefan Weber. I made a further small update for 7.8 because
886        there is a change of source arrangements: the pcre_searchfuncs.c module is
887        replaced by pcre_ucd.c.
890    Version 7.7 07-May-08
891    ---------------------
893    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
894        a string to a long long, pretend we don't even have a long long." This is
895        done by checking for the strtoq, strtoll, and _strtoi64 functions.
897    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
898        pre-7.6 versions, which defined a global no_arg variable instead of putting
899        it in the RE class. (See also #8 below.)
901    3.  Remove a line of dead code, identified by coverity and reported by Nuno
902        Lopes.
904    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
906        (1) The include/exclude patterns were being applied to the whole pathnames
907            of files, instead of just to the final components.
909        (2) If there was more than one level of directory, the subdirectories were
910            skipped unless they satisfied the include/exclude conditions. This is
911            inconsistent with GNU grep (and could even be seen as contrary to the
912            pcregrep specification - which I improved to make it absolutely clear).
913            The action now is always to scan all levels of directory, and just
914            apply the include/exclude patterns to regular files.
916    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
917        --exclude_dir in the tests to avoid scanning .svn directories.
919    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
920        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
921        doesn't support NULs in patterns.
923    7.  Added some missing "const"s to declarations of static tables in
924        pcre_compile.c and pcre_dfa_exec.c.
926    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
927        caused by fix #2  above. (Subsequently also a second patch to fix the
928        first patch. And a third patch - this was a messy problem.)
930    9.  Applied Craig's patch to remove the use of push_back().
932    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
933        matching function regexec().
935    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
936        which, however, unlike Perl's \g{...}, are subroutine calls, not back
937        references. PCRE supports relative numbers with this syntax (I don't think
938        Oniguruma does).
940    12. Previously, a group with a zero repeat such as (...){0} was completely
941        omitted from the compiled regex. However, this means that if the group
942        was called as a subroutine from elsewhere in the pattern, things went wrong
943        (an internal error was given). Such groups are now left in the compiled
944        pattern, with a new opcode that causes them to be skipped at execution
945        time.
947    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
948        to the way PCRE behaves:
950        (a) A lone ] character is dis-allowed (Perl treats it as data).
952        (b) A back reference to an unmatched subpattern matches an empty string
953            (Perl fails the current match path).
955        (c) A data ] in a character class must be notated as \] because if the
956            first data character in a class is ], it defines an empty class. (In
957            Perl it is not possible to have an empty class.) The empty class []
958            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
959            The negative empty class [^] matches any one character, independently
960            of the DOTALL setting.
962    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
963        non-existent subpattern following a character class starting with ']' and
964        containing () gave an internal compiling error instead of "reference to
965        non-existent subpattern". Fortunately, when the pattern did exist, the
966        compiled code was correct. (When scanning forwards to check for the
967        existencd of the subpattern, it was treating the data ']' as terminating
968        the class, so got the count wrong. When actually compiling, the reference
969        was subsequently set up correctly.)
971    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
972        it was being rejected as not supported by pcre_dfa_exec(), even though
973        other assertions are supported. I have made pcre_dfa_exec() support
974        (*FAIL).
976    16. The implementation of 13c above involved the invention of a new opcode,
977        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
978        cannot be changed at match time, I realized I could make a small
979        improvement to matching performance by compiling OP_ALLANY instead of
980        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
981        on the OP_ANY path.
983    17. Compiling pcretest on Windows with readline support failed without the
984        following two fixes: (1) Make the unistd.h include conditional on
985        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
987    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
988        ncurses library to be included for pcretest when ReadLine support is
989        requested, but also to allow for it to be overridden. This patch came from
990        Daniel Bergström.
992    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
993        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
994        any errors with the current Unicode tables. Thanks to Peter Kankowski for
995        spotting this.
998    Version 7.6 28-Jan-08
999    ---------------------
1001    1.  A character class containing a very large number of characters with
1002        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1003        overflow.
1005    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
1006        HAVE_LONG_LONG is not defined.
1008    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
1009        bring them up to date and include new features. This patch includes:
1011        - Fixed PH's badly added libz and libbz2 support.
1012        - Fixed a problem with static linking.
1013        - Added pcredemo. [But later removed - see 7 below.]
1014        - Fixed dftables problem and added an option.
1015        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1016            HAVE_LONG_LONG.
1017        - Added readline support for pcretest.
1018        - Added an listing of the option settings after cmake has run.
1020    4.  A user submitted a patch to Makefile that makes it easy to create
1021        "pcre.dll" under mingw when using Configure/Make. I added stuff to
1022        Makefile.am that cause it to include this special target, without
1023        affecting anything else. Note that the same mingw target plus all
1024        the other distribution libraries and programs are now supported
1025        when configuring with CMake (see 6 below) instead of with
1026        Configure/Make.
1028    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1029        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1030        exported in the Windows port". It has not yet been confirmed that the patch
1031        solves the problem, but it does no harm.
1033    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1034        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1035        with CMake, and also correct the comment about stack recursion.
1037    7.  Remove the automatic building of pcredemo from the ./configure system and
1038        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1039        of a program that users should build themselves after PCRE is installed, so
1040        building it automatically is not really right. What is more, it gave
1041        trouble in some build environments.
1043    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
1046    Version 7.5 10-Jan-08
1047    ---------------------
1049    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
1050        values in parens when parsing an RE using the C++ wrapper."
1052    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
1053        Characters greater than 255 were excluded from the class instead of being
1054        included.
1056    3.  The same bug as (2) above applied to negated POSIX classes such as
1057        [:^space:].
1059    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1060        defined or documented. It seems to have been a typo for PCRE_STATIC, so
1061        I have changed it.
1063    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
1064        first named subpattern) and a construct such as (?&a) would reference the
1065        first named subpattern whose name started with "a" (in other words, the
1066        length check was missing). Both these problems are fixed. "Subpattern name
1067        expected" is now given for (?&) (a zero-length name), and this patch also
1068        makes it give the same error for \k'' (previously it complained that that
1069        was a reference to a non-existent subpattern).
1071    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
1072        this is right because (?- can be followed by option settings as well as by
1073        digits. I have, however, made the messages clearer.
1075    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1076        than the number used in the conditional) now cause a compile-time error.
1077        This is actually not compatible with Perl, which accepts such patterns, but
1078        treats the conditional as always being FALSE (as PCRE used to), but it
1079        seems to me that giving a diagnostic is better.
1081    8.  Change "alphameric" to the more common word "alphanumeric" in comments
1082        and messages.
1084    9.  Fix two occurrences of "backslash" in comments that should have been
1085        "backspace".
1087    10. Remove two redundant lines of code that can never be obeyed (their function
1088        was moved elsewhere).
1090    11. The program that makes PCRE's Unicode character property table had a bug
1091        which caused it to generate incorrect table entries for sequences of
1092        characters that have the same character type, but are in different scripts.
1093        It amalgamated them into a single range, with the script of the first of
1094        them. In other words, some characters were in the wrong script. There were
1095        thirteen such cases, affecting characters in the following ranges:
1097          U+002b0 - U+002c1
1098          U+0060c - U+0060d
1099          U+0061e - U+00612
1100          U+0064b - U+0065e
1101          U+0074d - U+0076d
1102          U+01800 - U+01805
1103          U+01d00 - U+01d77
1104          U+01d9b - U+01dbf
1105          U+0200b - U+0200f
1106          U+030fc - U+030fe
1107          U+03260 - U+0327f
1108          U+0fb46 - U+0fbb1
1109          U+10450 - U+1049d
1111    12. The -o option (show only the matching part of a line) for pcregrep was not
1112        compatible with GNU grep in that, if there was more than one match in a
1113        line, it showed only the first of them. It now behaves in the same way as
1114        GNU grep.
1116    13. If the -o and -v options were combined for pcregrep, it printed a blank
1117        line for every non-matching line. GNU grep prints nothing, and pcregrep now
1118        does the same. The return code can be used to tell if there were any
1119        non-matching lines.
1121    14. Added --file-offsets and --line-offsets to pcregrep.
1123    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1124        infinitely looping recursion. The bug was that positive lookaheads were not
1125        being skipped when checking for a possible empty match (negative lookaheads
1126        and both kinds of lookbehind were skipped).
1128    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1129        inclusion of <windows.h> to before rather than after the definition of
1130        INVALID_FILE_ATTRIBUTES (patch from David Byron).
1132    17. Specifying a possessive quantifier with a specific limit for a Unicode
1133        character property caused pcre_compile() to compile bad code, which led at
1134        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1135        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1136        caused the error; without that there was no problem.
1138    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1140    19. Added --enable-pcretest-libreadline.
1142    20. In pcrecpp.cc, the variable 'count' was incremented twice in
1143        RE::GlobalReplace(). As a result, the number of replacements returned was
1144        double what it should be. I removed one of the increments, but Craig sent a
1145        later patch that removed the other one (the right fix) and added unit tests
1146        that check the return values (which was not done before).
1148    21. Several CMake things:
1150        (1) Arranged that, when cmake is used on Unix, the libraries end up with
1151            the names libpcre and libpcreposix, not just pcre and pcreposix.
1153        (2) The above change means that pcretest and pcregrep are now correctly
1154            linked with the newly-built libraries, not previously installed ones.
1158    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1159        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1160        UTF-8 newline character). The key issue is that the pattern starts .*;
1161        this means that the match must be either at the beginning, or after a
1162        newline. The bug was in the code for advancing after a failed match and
1163        checking that the new position followed a newline. It was not taking
1164        account of UTF-8 characters correctly.
1166    23. PCRE was behaving differently from Perl in the way it recognized POSIX
1167        character classes. PCRE was not treating the sequence [:...:] as a
1168        character class unless the ... were all letters. Perl, however, seems to
1169        allow any characters between [: and :], though of course it rejects as
1170        unknown any "names" that contain non-letters, because all the known class
1171        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1172        for example, whereas PCRE did not - it did not recognize a POSIX character
1173        class. This seemed a bit dangerous, so the code has been changed to be
1174        closer to Perl. The behaviour is not identical to Perl, because PCRE will
1175        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1176        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1177        Perl does, and where it didn't before.
1179    24. Rewrite so as to remove the single use of %n from pcregrep because in some
1180        Windows environments %n is disabled by default.
1183    Version 7.4 21-Sep-07
1184    ---------------------
1186    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
1187        means that a class such as [\s] counted as "explicit reference to CR or
1188        LF". That isn't really right - the whole point of the change was to try to
1189        help when there was an actual mention of one of the two characters. So now
1190        the change happens only if \r or \n (or a literal CR or LF) character is
1191        encountered.
1193    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
1194        of both had grown to the point where there were only 3 bits left.
1195        Fortunately, there was spare space in the data structure, and so I have
1196        moved the internal flags into a new 16-bit field to free up more option
1197        bits.
1199    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1200        but did not set the internal JCHANGED flag - either of these is enough to
1201        control the way the "get" function works - but the PCRE_INFO_JCHANGED
1202        facility is supposed to tell if (?J) was ever used, so now (?J) at the
1203        start sets both bits.
1205    4.  Added options (at build time, compile time, exec time) to change \R from
1206        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1208    5.  doc/pcresyntax.html was missing from the distribution.
1210    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1211        compatibility, even though it is no longer used.
1213    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1214        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1215        windows.h file is present (where different names are used). [This was
1216        reversed later after testing - see 16 below.]
1218    8.  Changed all #include <config.h> to #include "config.h". There were also
1219        some further <pcre.h> cases that I changed to "pcre.h".
1221    9.  When pcregrep was used with the --colour option, it missed the line ending
1222        sequence off the lines that it output.
1224    10. It was pointed out to me that arrays of string pointers cause lots of
1225        relocations when a shared library is dynamically loaded. A technique of
1226        using a single long string with a table of offsets can drastically reduce
1227        these. I have refactored PCRE in four places to do this. The result is
1228        dramatic:
1230          Originally:                          290
1231          After changing UCP table:            187
1232          After changing error message table:   43
1233          After changing table of "verbs"       36
1234          After changing table of Posix names   22
1236        Thanks to the folks working on Gregex for glib for this insight.
1238    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1239        unicode-properties was also set.
1241    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1243    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1244        checked only for CRLF.
1246    14. Added casts to pcretest.c to avoid compiler warnings.
1248    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1250    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1251        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1252        entirely. This removes changes made in 7 above.
1254    17. The CMake files have been updated, and there is now more information about
1255        building with CMake in the NON-UNIX-USE document.
1258    Version 7.3 28-Aug-07
1259    ---------------------
1261     1. In the rejigging of the build system that eventually resulted in 7.1, the
1262        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1263        brackets there is not right, since it causes compilers to look for an
1264        installed pcre.h, not the version that is in the source that is being
1265        compiled (which of course may be different). I have changed it back to:
1267          #include "pcre.h"
1269        I have a vague recollection that the change was concerned with compiling in
1270        different directories, but in the new build system, that is taken care of
1271        by the VPATH setting the Makefile.
1273     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1274        when the subject happened to end in the byte 0x85 (e.g. if the last
1275        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1276        characters but of course it shouldn't be taken as a newline when it is part
1277        of another character. The bug was that, for an unlimited repeat of . in
1278        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1279        characters when looking for a newline.
1281     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1283     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1284        in debug output.
1286     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1287        long printing in the pcrecpp unittest when running under MinGW.
1289     6. ESC_K was left out of the EBCDIC table.
1291     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1292        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1293        limit also applies to "virtual nesting" when a pattern is recursive, and in
1294        this case 1000 isn't so big. I have been able to remove this limit at the
1295        expense of backing off one optimization in certain circumstances. Normally,
1296        when pcre_exec() would call its internal match() function recursively and
1297        immediately return the result unconditionally, it uses a "tail recursion"
1298        feature to save stack. However, when a subpattern that can match an empty
1299        string has an unlimited repetition quantifier, it no longer makes this
1300        optimization. That gives it a stack frame in which to save the data for
1301        checking that an empty string has been matched. Previously this was taken
1302        from the 1000-entry workspace that had been reserved. So now there is no
1303        explicit limit, but more stack is used.
1305     8. Applied Daniel's patches to solve problems with the import/export magic
1306        syntax that is required for Windows, and which was going wrong for the
1307        pcreposix and pcrecpp parts of the library. These were overlooked when this
1308        problem was solved for the main library.
1310     9. There were some crude static tests to avoid integer overflow when computing
1311        the size of patterns that contain repeated groups with explicit upper
1312        limits. As the maximum quantifier is 65535, the maximum group length was
1313        set at 30,000 so that the product of these two numbers did not overflow a
1314        32-bit integer. However, it turns out that people want to use groups that
1315        are longer than 30,000 bytes (though not repeat them that many times).
1316        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1317        made it possible to implement the integer overflow checks in a much more
1318        dynamic way, which I have now done. The artificial limitation on group
1319        length has been removed - we now have only the limit on the total length of
1320        the compiled pattern, which depends on the LINK_SIZE setting.
1322    10. Fixed a bug in the documentation for get/copy named substring when
1323        duplicate names are permitted. If none of the named substrings are set, the
1324        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1325        empty string.
1327    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1328        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1329        because the ] is interpreted as the first data character and the
1330        terminating ] is not found. PCRE has been made compatible with Perl in this
1331        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1332        cause memory overwriting.
1334    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1335        string has been matched (to stop an infinite loop). It was not recognizing
1336        a conditional subpattern that could match an empty string if that
1337        subpattern was within another subpattern. For example, it looped when
1338        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1339        condition was not nested. This bug has been fixed.
1341    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1342        past the start of the subject in the presence of bytes with the top bit
1343        set, for example "\x8aBCD".
1345    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1346        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1348    14. Optimized (?!) to (*FAIL).
1350    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1351        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1352        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1353        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1354        does: it's just the validity check that is more restrictive.
1356    16. Inserted checks for integer overflows during escape sequence (backslash)
1357        processing, and also fixed erroneous offset values for syntax errors during
1358        backslash processing.
1360    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1361        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1363    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1364        caused an overrun.
1366    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1367        something other than just ASCII characters) inside a group that had an
1368        unlimited repeat caused a loop at compile time (while checking to see
1369        whether the group could match an empty string).
1371    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1372        [\P{Any}] did so. (Error in the code for printing property names.)
1374    21. An orphan \E inside a character class could cause a crash.
1376    22. A repeated capturing bracket such as (A)? could cause a wild memory
1377        reference during compilation.
1379    23. There are several functions in pcre_compile() that scan along a compiled
1380        expression for various reasons (e.g. to see if it's fixed length for look
1381        behind). There were bugs in these functions when a repeated \p or \P was
1382        present in the pattern. These operators have additional parameters compared
1383        with \d, etc, and these were not being taken into account when moving along
1384        the compiled data. Specifically:
1386        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1387            length.
1389        (b) An item such as \pL+ within a repeated group could cause crashes or
1390            loops.
1392        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1393            "reference to non-existent subpattern" error.
1395        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1397    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1398        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1400    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1402    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1403        character were causing crashes (broken optimization).
1405    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1406        \p or \P) caused a compile-time loop.
1408    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1409        break. For example, the unstudied pattern [\r\n]A does not match the string
1410        "\r\nA" because change 7.0/46 below moves the current point on by two
1411        characters after failing to match at the start. However, the pattern \nA
1412        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1413        the same is true. There doesn't seem any very clean way out of this, but
1414        what I have chosen to do makes the common cases work: PCRE now takes note
1415        of whether there can be an explicit match for \r or \n anywhere in the
1416        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1417        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1418        pattern has explicit CR or LF references.
1420    29. Added (*CR) etc for changing newline setting at start of pattern.
1423    Version 7.2 19-Jun-07
1424    ---------------------
1426     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1427        which is apparently normally available under Windows.
1429     2. Re-jig the pcregrep tests with different newline settings in an attempt
1430        to make them independent of the local environment's newline setting.
1432     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1434     4. Some of the "internals" tests were previously cut out when the link size
1435        was not 2, because the output contained actual offsets. The recent new
1436        "Z" feature of pcretest means that these can be cut out, making the tests
1437        usable with all link sizes.
1439     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1440        stack recursion. This gives a massive performance boost under BSD, but just
1441        a small improvement under Linux. However, it saves one field in the frame
1442        in all cases.
1444     6. Added more features from the forthcoming Perl 5.10:
1446        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1447            recursion call. It refers to the nth most recently opened parentheses.
1449        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1450            to be opened parentheses.
1452        (c) Conditions that refer to capturing parentheses can be specified
1453            relatively, for example, (?(-2)... or (?(+3)...
1455        (d) \K resets the start of the current match so that everything before
1456            is not part of it.
1458        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1460        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1461            reference syntax.
1463        (g) (?| introduces a group in which the numbering of parentheses in each
1464            alternative starts with the same number.
1466        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1468     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1471     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1472        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1473        for detecting groups that can match an empty string.
1475     9. A pattern with a very large number of alternatives (more than several
1476        hundred) was running out of internal workspace during the pre-compile
1477        phase, where pcre_compile() figures out how much memory will be needed. A
1478        bit of new cunning has reduced the workspace needed for groups with
1479        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1480        workspace instead of running out of the 4096 that are available.
1482    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1484    11. Applied patch from Google to remove an optimization that didn't quite work.
1485        The report of the bug said:
1487          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1488          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1489          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1491    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1492        it matched the wrong number of bytes.
1495    Version 7.1 24-Apr-07
1496  ---------------------  ---------------------
1498   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
# Line 149  Version 7.1 12-Mar-07 Line 1640  Version 7.1 12-Mar-07
1641  23. Added some casts to kill warnings from HP-UX ia64 compiler.  23. Added some casts to kill warnings from HP-UX ia64 compiler.
1643    24. Added a man page for pcre-config.
1646  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
1647  ---------------------  ---------------------

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