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revision 104 by ph10, Tue Mar 6 16:25:15 2007 UTC revision 369 by ph10, Sun Aug 24 16:53:47 2008 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  Version 7.8 25-Aug-08
5  ---------------------  ---------------------
6    
7   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one  1.  Replaced UCP searching code with optimized version as implemented for Ad
8      that is more "standard", making use of automake and other autotools. There      Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9      is some re-arrangement of the files and adjustment of comments consequent      stage table and inline lookup instead of a function, giving speed ups of 2
10      on this.      to 5 times on some simple patterns that I tested. Permission was given to
11        distribute the MultiStage2.py script that generates the tables (it's not in
12        the tarball, but is in the Subversion repository).
13    
14    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15        scripts.
16    
17    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18        a group with a zero qualifier. The result of the study could be incorrect,
19        or the function might crash, depending on the pattern.
20    
21    4.  Caseless matching was not working for non-ASCII characters in back
22        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23        It now works when Unicode Property Support is available.
24    
25    5.  In pcretest, an escape such as \x{de} in the data was always generating
26        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28        truncation.
29    
30    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
31    
32    7.  Added two (int) casts to pcregrep when printing the difference of two
33        pointers, in case they are 64-bit values.
34    
35   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r  8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
36      for recursive directory scanning broke on some systems because the files      test 2 if it fails.
     are not scanned in any specific order and on different systems the order  
     was different. A call to "sort" has been inserted into RunGrepTest for the  
     approprate test as a short-term fix. In the longer term there may be an  
     alternative.  
37    
38   3. I had an email from Eric Raymond about problems translating some of PCRE's  9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
39      man pages to HTML (despite the fact that I distribute HTML pages, some      and a #define of that name to empty if it is not externally set. This is to
40      people do their own conversions for various reasons). The problems      allow users of MSVC to set it if necessary.
     concerned the use of low-level troff macros .br and .in. I have therefore  
     removed all such uses from the man pages (some were redundant, some could  
     be replaced by .nf/.fi pairs). The maintain/132html script that I use to  
     generate HTML has been updated to handle .nf/.fi and to complain if it  
     encounters .br or .in.  
41    
42   4. Updated comments in configure.ac that get placed in config.h.in and also  10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
43      arranged for config.h to be included in the distribution, for the benefit      the convenience functions in the pcre_get.c source file.
     of those who have to compile without Autotools (compare pcre.h).  
44    
45   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan  11. An option change at the start of a pattern that had top-level alternatives
46      Weber: (1) pcre_internal.h was missing some function renames; (2) updated      could cause overwriting and/or a crash. This command provoked a crash in
47      makevp.bat for the current PCRE, using the additional files !compile.txt,      some environments:
48      !linklib.txt, and pcregexp.pas.  
49          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
50    
51        This potential security problem was recorded as CVE-2008-2371.
52    
53   6. A Windows user reported a minor discrepancy with test 2, which turned out  12. For a pattern where the match had to start at the beginning or immediately
54      to be caused by a trailing space on an input line that had got lost in his      after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
55      copy. The trailing space was an accident, so I've just removed it.      pcre_dfa_exec() could read past the end of the passed subject if there was
56        no match. To help with detecting such bugs (e.g. with valgrind), I modified
57        pcretest so that it places the subject at the end of its malloc-ed buffer.
58    
59   7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told  13. The change to pcretest in 12 above threw up a couple more cases when pcre_
60      that is needed.      exec() might read past the end of the data buffer in UTF-8 mode.
61    
62    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
63        the data contained the byte 0x85 as part of a UTF-8 character within its
64        first line. This applied both to normal and DFA matching.
65    
66    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
67        /^[^d]*?$/8 failed to match "abc".
68    
69    16. Added a missing copyright notice to pcrecpp_internal.h.
70    
71    17. Make it more clear in the documentation that values returned from
72        pcre_exec() in ovector are byte offsets, not character counts.
73    
74    18. Tidied a few places to stop certain compilers from issuing warnings.
75    
76    
77    Version 7.7 07-May-08
78    ---------------------
79    
80    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
81        a string to a long long, pretend we don't even have a long long." This is
82        done by checking for the strtoq, strtoll, and _strtoi64 functions.
83    
84    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
85        pre-7.6 versions, which defined a global no_arg variable instead of putting
86        it in the RE class. (See also #8 below.)
87    
88    3.  Remove a line of dead code, identified by coverity and reported by Nuno
89        Lopes.
90    
91    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
92    
93        (1) The include/exclude patterns were being applied to the whole pathnames
94            of files, instead of just to the final components.
95    
96        (2) If there was more than one level of directory, the subdirectories were
97            skipped unless they satisfied the include/exclude conditions. This is
98            inconsistent with GNU grep (and could even be seen as contrary to the
99            pcregrep specification - which I improved to make it absolutely clear).
100            The action now is always to scan all levels of directory, and just
101            apply the include/exclude patterns to regular files.
102    
103    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
104        --exclude_dir in the tests to avoid scanning .svn directories.
105    
106    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
107        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
108        doesn't support NULs in patterns.
109    
110    7.  Added some missing "const"s to declarations of static tables in
111        pcre_compile.c and pcre_dfa_exec.c.
112    
113    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
114        caused by fix #2  above. (Subsequently also a second patch to fix the
115        first patch. And a third patch - this was a messy problem.)
116    
117    9.  Applied Craig's patch to remove the use of push_back().
118    
119    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
120        matching function regexec().
121    
122    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
123        which, however, unlike Perl's \g{...}, are subroutine calls, not back
124        references. PCRE supports relative numbers with this syntax (I don't think
125        Oniguruma does).
126    
127    12. Previously, a group with a zero repeat such as (...){0} was completely
128        omitted from the compiled regex. However, this means that if the group
129        was called as a subroutine from elsewhere in the pattern, things went wrong
130        (an internal error was given). Such groups are now left in the compiled
131        pattern, with a new opcode that causes them to be skipped at execution
132        time.
133    
134    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
135        to the way PCRE behaves:
136    
137        (a) A lone ] character is dis-allowed (Perl treats it as data).
138    
139        (b) A back reference to an unmatched subpattern matches an empty string
140            (Perl fails the current match path).
141    
142        (c) A data ] in a character class must be notated as \] because if the
143            first data character in a class is ], it defines an empty class. (In
144            Perl it is not possible to have an empty class.) The empty class []
145            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
146            The negative empty class [^] matches any one character, independently
147            of the DOTALL setting.
148    
149    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
150        non-existent subpattern following a character class starting with ']' and
151        containing () gave an internal compiling error instead of "reference to
152        non-existent subpattern". Fortunately, when the pattern did exist, the
153        compiled code was correct. (When scanning forwards to check for the
154        existencd of the subpattern, it was treating the data ']' as terminating
155        the class, so got the count wrong. When actually compiling, the reference
156        was subsequently set up correctly.)
157    
158    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
159        it was being rejected as not supported by pcre_dfa_exec(), even though
160        other assertions are supported. I have made pcre_dfa_exec() support
161        (*FAIL).
162    
163    16. The implementation of 13c above involved the invention of a new opcode,
164        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
165        cannot be changed at match time, I realized I could make a small
166        improvement to matching performance by compiling OP_ALLANY instead of
167        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
168        on the OP_ANY path.
169    
170    17. Compiling pcretest on Windows with readline support failed without the
171        following two fixes: (1) Make the unistd.h include conditional on
172        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
173    
174    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
175        ncurses library to be included for pcretest when ReadLine support is
176        requested, but also to allow for it to be overridden. This patch came from
177        Daniel Bergström.
178    
179    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
180        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
181        any errors with the current Unicode tables. Thanks to Peter Kankowski for
182        spotting this.
183    
184    
185    Version 7.6 28-Jan-08
186    ---------------------
187    
188    1.  A character class containing a very large number of characters with
189        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
190        overflow.
191    
192    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
193        HAVE_LONG_LONG is not defined.
194    
195    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
196        bring them up to date and include new features. This patch includes:
197    
198        - Fixed PH's badly added libz and libbz2 support.
199        - Fixed a problem with static linking.
200        - Added pcredemo. [But later removed - see 7 below.]
201        - Fixed dftables problem and added an option.
202        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
203            HAVE_LONG_LONG.
204        - Added readline support for pcretest.
205        - Added an listing of the option settings after cmake has run.
206    
207    4.  A user submitted a patch to Makefile that makes it easy to create
208        "pcre.dll" under mingw when using Configure/Make. I added stuff to
209        Makefile.am that cause it to include this special target, without
210        affecting anything else. Note that the same mingw target plus all
211        the other distribution libraries and programs are now supported
212        when configuring with CMake (see 6 below) instead of with
213        Configure/Make.
214    
215    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
216        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
217        exported in the Windows port". It has not yet been confirmed that the patch
218        solves the problem, but it does no harm.
219    
220    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
221        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
222        with CMake, and also correct the comment about stack recursion.
223    
224    7.  Remove the automatic building of pcredemo from the ./configure system and
225        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
226        of a program that users should build themselves after PCRE is installed, so
227        building it automatically is not really right. What is more, it gave
228        trouble in some build environments.
229    
230    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
231    
232    
233    Version 7.5 10-Jan-08
234    ---------------------
235    
236    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
237        values in parens when parsing an RE using the C++ wrapper."
238    
239    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
240        Characters greater than 255 were excluded from the class instead of being
241        included.
242    
243    3.  The same bug as (2) above applied to negated POSIX classes such as
244        [:^space:].
245    
246    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
247        defined or documented. It seems to have been a typo for PCRE_STATIC, so
248        I have changed it.
249    
250    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
251        first named subpattern) and a construct such as (?&a) would reference the
252        first named subpattern whose name started with "a" (in other words, the
253        length check was missing). Both these problems are fixed. "Subpattern name
254        expected" is now given for (?&) (a zero-length name), and this patch also
255        makes it give the same error for \k'' (previously it complained that that
256        was a reference to a non-existent subpattern).
257    
258    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
259        this is right because (?- can be followed by option settings as well as by
260        digits. I have, however, made the messages clearer.
261    
262    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
263        than the number used in the conditional) now cause a compile-time error.
264        This is actually not compatible with Perl, which accepts such patterns, but
265        treats the conditional as always being FALSE (as PCRE used to), but it
266        seems to me that giving a diagnostic is better.
267    
268    8.  Change "alphameric" to the more common word "alphanumeric" in comments
269        and messages.
270    
271    9.  Fix two occurrences of "backslash" in comments that should have been
272        "backspace".
273    
274    10. Remove two redundant lines of code that can never be obeyed (their function
275        was moved elsewhere).
276    
277    11. The program that makes PCRE's Unicode character property table had a bug
278        which caused it to generate incorrect table entries for sequences of
279        characters that have the same character type, but are in different scripts.
280        It amalgamated them into a single range, with the script of the first of
281        them. In other words, some characters were in the wrong script. There were
282        thirteen such cases, affecting characters in the following ranges:
283    
284          U+002b0 - U+002c1
285          U+0060c - U+0060d
286          U+0061e - U+00612
287          U+0064b - U+0065e
288          U+0074d - U+0076d
289          U+01800 - U+01805
290          U+01d00 - U+01d77
291          U+01d9b - U+01dbf
292          U+0200b - U+0200f
293          U+030fc - U+030fe
294          U+03260 - U+0327f
295          U+0fb46 - U+0fbb1
296          U+10450 - U+1049d
297    
298    12. The -o option (show only the matching part of a line) for pcregrep was not
299        compatible with GNU grep in that, if there was more than one match in a
300        line, it showed only the first of them. It now behaves in the same way as
301        GNU grep.
302    
303    13. If the -o and -v options were combined for pcregrep, it printed a blank
304        line for every non-matching line. GNU grep prints nothing, and pcregrep now
305        does the same. The return code can be used to tell if there were any
306        non-matching lines.
307    
308    14. Added --file-offsets and --line-offsets to pcregrep.
309    
310    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
311        infinitely looping recursion. The bug was that positive lookaheads were not
312        being skipped when checking for a possible empty match (negative lookaheads
313        and both kinds of lookbehind were skipped).
314    
315    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
316        inclusion of <windows.h> to before rather than after the definition of
317        INVALID_FILE_ATTRIBUTES (patch from David Byron).
318    
319    17. Specifying a possessive quantifier with a specific limit for a Unicode
320        character property caused pcre_compile() to compile bad code, which led at
321        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
322        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
323        caused the error; without that there was no problem.
324    
325    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
326    
327    19. Added --enable-pcretest-libreadline.
328    
329    20. In pcrecpp.cc, the variable 'count' was incremented twice in
330        RE::GlobalReplace(). As a result, the number of replacements returned was
331        double what it should be. I removed one of the increments, but Craig sent a
332        later patch that removed the other one (the right fix) and added unit tests
333        that check the return values (which was not done before).
334    
335    21. Several CMake things:
336    
337        (1) Arranged that, when cmake is used on Unix, the libraries end up with
338            the names libpcre and libpcreposix, not just pcre and pcreposix.
339    
340        (2) The above change means that pcretest and pcregrep are now correctly
341            linked with the newly-built libraries, not previously installed ones.
342    
343        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
344    
345    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
346        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
347        UTF-8 newline character). The key issue is that the pattern starts .*;
348        this means that the match must be either at the beginning, or after a
349        newline. The bug was in the code for advancing after a failed match and
350        checking that the new position followed a newline. It was not taking
351        account of UTF-8 characters correctly.
352    
353    23. PCRE was behaving differently from Perl in the way it recognized POSIX
354        character classes. PCRE was not treating the sequence [:...:] as a
355        character class unless the ... were all letters. Perl, however, seems to
356        allow any characters between [: and :], though of course it rejects as
357        unknown any "names" that contain non-letters, because all the known class
358        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
359        for example, whereas PCRE did not - it did not recognize a POSIX character
360        class. This seemed a bit dangerous, so the code has been changed to be
361        closer to Perl. The behaviour is not identical to Perl, because PCRE will
362        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
363        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
364        Perl does, and where it didn't before.
365    
366    24. Rewrite so as to remove the single use of %n from pcregrep because in some
367        Windows environments %n is disabled by default.
368    
369    
370    Version 7.4 21-Sep-07
371    ---------------------
372    
373    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
374        means that a class such as [\s] counted as "explicit reference to CR or
375        LF". That isn't really right - the whole point of the change was to try to
376        help when there was an actual mention of one of the two characters. So now
377        the change happens only if \r or \n (or a literal CR or LF) character is
378        encountered.
379    
380    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
381        of both had grown to the point where there were only 3 bits left.
382        Fortunately, there was spare space in the data structure, and so I have
383        moved the internal flags into a new 16-bit field to free up more option
384        bits.
385    
386    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
387        but did not set the internal JCHANGED flag - either of these is enough to
388        control the way the "get" function works - but the PCRE_INFO_JCHANGED
389        facility is supposed to tell if (?J) was ever used, so now (?J) at the
390        start sets both bits.
391    
392    4.  Added options (at build time, compile time, exec time) to change \R from
393        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
394    
395    5.  doc/pcresyntax.html was missing from the distribution.
396    
397    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
398        compatibility, even though it is no longer used.
399    
400    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
401        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
402        windows.h file is present (where different names are used). [This was
403        reversed later after testing - see 16 below.]
404    
405    8.  Changed all #include <config.h> to #include "config.h". There were also
406        some further <pcre.h> cases that I changed to "pcre.h".
407    
408    9.  When pcregrep was used with the --colour option, it missed the line ending
409        sequence off the lines that it output.
410    
411    10. It was pointed out to me that arrays of string pointers cause lots of
412        relocations when a shared library is dynamically loaded. A technique of
413        using a single long string with a table of offsets can drastically reduce
414        these. I have refactored PCRE in four places to do this. The result is
415        dramatic:
416    
417          Originally:                          290
418          After changing UCP table:            187
419          After changing error message table:   43
420          After changing table of "verbs"       36
421          After changing table of Posix names   22
422    
423        Thanks to the folks working on Gregex for glib for this insight.
424    
425    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
426        unicode-properties was also set.
427    
428    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
429    
430    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
431        checked only for CRLF.
432    
433    14. Added casts to pcretest.c to avoid compiler warnings.
434    
435    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
436    
437    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
438        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
439        entirely. This removes changes made in 7 above.
440    
441    17. The CMake files have been updated, and there is now more information about
442        building with CMake in the NON-UNIX-USE document.
443    
444    
445    Version 7.3 28-Aug-07
446    ---------------------
447    
448     1. In the rejigging of the build system that eventually resulted in 7.1, the
449        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
450        brackets there is not right, since it causes compilers to look for an
451        installed pcre.h, not the version that is in the source that is being
452        compiled (which of course may be different). I have changed it back to:
453    
454          #include "pcre.h"
455    
456        I have a vague recollection that the change was concerned with compiling in
457        different directories, but in the new build system, that is taken care of
458        by the VPATH setting the Makefile.
459    
460     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
461        when the subject happened to end in the byte 0x85 (e.g. if the last
462        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
463        characters but of course it shouldn't be taken as a newline when it is part
464        of another character. The bug was that, for an unlimited repeat of . in
465        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
466        characters when looking for a newline.
467    
468     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
469    
470     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
471        in debug output.
472    
473     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
474        long printing in the pcrecpp unittest when running under MinGW.
475    
476     6. ESC_K was left out of the EBCDIC table.
477    
478     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
479        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
480        limit also applies to "virtual nesting" when a pattern is recursive, and in
481        this case 1000 isn't so big. I have been able to remove this limit at the
482        expense of backing off one optimization in certain circumstances. Normally,
483        when pcre_exec() would call its internal match() function recursively and
484        immediately return the result unconditionally, it uses a "tail recursion"
485        feature to save stack. However, when a subpattern that can match an empty
486        string has an unlimited repetition quantifier, it no longer makes this
487        optimization. That gives it a stack frame in which to save the data for
488        checking that an empty string has been matched. Previously this was taken
489        from the 1000-entry workspace that had been reserved. So now there is no
490        explicit limit, but more stack is used.
491    
492     8. Applied Daniel's patches to solve problems with the import/export magic
493        syntax that is required for Windows, and which was going wrong for the
494        pcreposix and pcrecpp parts of the library. These were overlooked when this
495        problem was solved for the main library.
496    
497     9. There were some crude static tests to avoid integer overflow when computing
498        the size of patterns that contain repeated groups with explicit upper
499        limits. As the maximum quantifier is 65535, the maximum group length was
500        set at 30,000 so that the product of these two numbers did not overflow a
501        32-bit integer. However, it turns out that people want to use groups that
502        are longer than 30,000 bytes (though not repeat them that many times).
503        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
504        made it possible to implement the integer overflow checks in a much more
505        dynamic way, which I have now done. The artificial limitation on group
506        length has been removed - we now have only the limit on the total length of
507        the compiled pattern, which depends on the LINK_SIZE setting.
508    
509    10. Fixed a bug in the documentation for get/copy named substring when
510        duplicate names are permitted. If none of the named substrings are set, the
511        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
512        empty string.
513    
514    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
515        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
516        because the ] is interpreted as the first data character and the
517        terminating ] is not found. PCRE has been made compatible with Perl in this
518        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
519        cause memory overwriting.
520    
521    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
522        string has been matched (to stop an infinite loop). It was not recognizing
523        a conditional subpattern that could match an empty string if that
524        subpattern was within another subpattern. For example, it looped when
525        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
526        condition was not nested. This bug has been fixed.
527    
528    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
529        past the start of the subject in the presence of bytes with the top bit
530        set, for example "\x8aBCD".
531    
532    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
533        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
534    
535    14. Optimized (?!) to (*FAIL).
536    
537    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
538        This restricts code points to be within the range 0 to 0x10FFFF, excluding
539        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
540        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
541        does: it's just the validity check that is more restrictive.
542    
543    16. Inserted checks for integer overflows during escape sequence (backslash)
544        processing, and also fixed erroneous offset values for syntax errors during
545        backslash processing.
546    
547    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
548        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
549    
550    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
551        caused an overrun.
552    
553    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
554        something other than just ASCII characters) inside a group that had an
555        unlimited repeat caused a loop at compile time (while checking to see
556        whether the group could match an empty string).
557    
558    20. Debugging a pattern containing \p or \P could cause a crash. For example,
559        [\P{Any}] did so. (Error in the code for printing property names.)
560    
561    21. An orphan \E inside a character class could cause a crash.
562    
563    22. A repeated capturing bracket such as (A)? could cause a wild memory
564        reference during compilation.
565    
566    23. There are several functions in pcre_compile() that scan along a compiled
567        expression for various reasons (e.g. to see if it's fixed length for look
568        behind). There were bugs in these functions when a repeated \p or \P was
569        present in the pattern. These operators have additional parameters compared
570        with \d, etc, and these were not being taken into account when moving along
571        the compiled data. Specifically:
572    
573        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
574            length.
575    
576        (b) An item such as \pL+ within a repeated group could cause crashes or
577            loops.
578    
579        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
580            "reference to non-existent subpattern" error.
581    
582        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
583    
584    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
585        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
586    
587    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
588    
589    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
590        character were causing crashes (broken optimization).
591    
592    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
593        \p or \P) caused a compile-time loop.
594    
595    28. More problems have arisen in unanchored patterns when CRLF is a valid line
596        break. For example, the unstudied pattern [\r\n]A does not match the string
597        "\r\nA" because change 7.0/46 below moves the current point on by two
598        characters after failing to match at the start. However, the pattern \nA
599        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
600        the same is true. There doesn't seem any very clean way out of this, but
601        what I have chosen to do makes the common cases work: PCRE now takes note
602        of whether there can be an explicit match for \r or \n anywhere in the
603        pattern, and if so, 7.0/46 no longer applies. As part of this change,
604        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
605        pattern has explicit CR or LF references.
606    
607    29. Added (*CR) etc for changing newline setting at start of pattern.
608    
609    
610    Version 7.2 19-Jun-07
611    ---------------------
612    
613     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
614        which is apparently normally available under Windows.
615    
616     2. Re-jig the pcregrep tests with different newline settings in an attempt
617        to make them independent of the local environment's newline setting.
618    
619     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
620    
621     4. Some of the "internals" tests were previously cut out when the link size
622        was not 2, because the output contained actual offsets. The recent new
623        "Z" feature of pcretest means that these can be cut out, making the tests
624        usable with all link sizes.
625    
626     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
627        stack recursion. This gives a massive performance boost under BSD, but just
628        a small improvement under Linux. However, it saves one field in the frame
629        in all cases.
630    
631     6. Added more features from the forthcoming Perl 5.10:
632    
633        (a) (?-n) (where n is a string of digits) is a relative subroutine or
634            recursion call. It refers to the nth most recently opened parentheses.
635    
636        (b) (?+n) is also a relative subroutine call; it refers to the nth next
637            to be opened parentheses.
638    
639        (c) Conditions that refer to capturing parentheses can be specified
640            relatively, for example, (?(-2)... or (?(+3)...
641    
642        (d) \K resets the start of the current match so that everything before
643            is not part of it.
644    
645        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
646    
647        (f) \g{name} is another synonym - part of Perl 5.10's unification of
648            reference syntax.
649    
650        (g) (?| introduces a group in which the numbering of parentheses in each
651            alternative starts with the same number.
652    
653        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
654    
655     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
656        PCRE_INFO_JCHANGED.
657    
658     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
659        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
660        for detecting groups that can match an empty string.
661    
662     9. A pattern with a very large number of alternatives (more than several
663        hundred) was running out of internal workspace during the pre-compile
664        phase, where pcre_compile() figures out how much memory will be needed. A
665        bit of new cunning has reduced the workspace needed for groups with
666        alternatives. The 1000-alternative test pattern now uses 12 bytes of
667        workspace instead of running out of the 4096 that are available.
668    
669    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
670    
671    11. Applied patch from Google to remove an optimization that didn't quite work.
672        The report of the bug said:
673    
674          pcrecpp::RE("a*").FullMatch("aaa") matches, while
675          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
676          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
677    
678    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
679        it matched the wrong number of bytes.
680    
681    
682    Version 7.1 24-Apr-07
683    ---------------------
684    
685     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
686        that is more "standard", making use of automake and other Autotools. There
687        is some re-arrangement of the files and adjustment of comments consequent
688        on this.
689    
690     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
691        for recursive directory scanning broke on some systems because the files
692        are not scanned in any specific order and on different systems the order
693        was different. A call to "sort" has been inserted into RunGrepTest for the
694        approprate test as a short-term fix. In the longer term there may be an
695        alternative.
696    
697     3. I had an email from Eric Raymond about problems translating some of PCRE's
698        man pages to HTML (despite the fact that I distribute HTML pages, some
699        people do their own conversions for various reasons). The problems
700        concerned the use of low-level troff macros .br and .in. I have therefore
701        removed all such uses from the man pages (some were redundant, some could
702        be replaced by .nf/.fi pairs). The 132html script that I use to generate
703        HTML has been updated to handle .nf/.fi and to complain if it encounters
704        .br or .in.
705    
706     4. Updated comments in configure.ac that get placed in config.h.in and also
707        arranged for config.h to be included in the distribution, with the name
708        config.h.generic, for the benefit of those who have to compile without
709        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
710    
711     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
712        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
713        makevp.bat for the current PCRE, using the additional files
714        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
715    
716     6. A Windows user reported a minor discrepancy with test 2, which turned out
717        to be caused by a trailing space on an input line that had got lost in his
718        copy. The trailing space was an accident, so I've just removed it.
719    
720     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
721        that is needed.
722    
723     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
724        as "const" (a) because they are and (b) because it helps the PHP
725        maintainers who have recently made a script to detect big data structures
726        in the php code that should be moved to the .rodata section. I remembered
727        to update Builducptable as well, so it won't revert if ucptable.h is ever
728        re-created.
729    
730     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
731        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
732        order to be able to cut out the UTF-8 tables in the latter when UTF-8
733        support is not required. This saves 1.5-2K of code, which is important in
734        some applications.
735    
736        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
737        so as not to refer to the tables, even though these functions will never be
738        called when UTF-8 support is disabled. Otherwise there are problems with a
739        shared library.
740    
741    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
742    
743        (a) It was defining its arguments as char * instead of void *.
744    
745        (b) It was assuming that all moves were upwards in memory; this was true
746            a long time ago when I wrote it, but is no longer the case.
747    
748        The emulated memove() is provided for those environments that have neither
749        memmove() nor bcopy(). I didn't think anyone used it these days, but that
750        is clearly not the case, as these two bugs were recently reported.
751    
752    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
753        and Detrail to create the HTML documentation, the .txt form of the man
754        pages, and it removes trailing spaces from listed files. It also creates
755        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
756        case, it wraps all the #defines with #ifndefs. This script should be run
757        before "make dist".
758    
759    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
760        with Unicode property support.
761    
762        (a) For a maximizing quantifier, if the two different cases of the
763            character were of different lengths in their UTF-8 codings (there are
764            some cases like this - I found 11), and the matching function had to
765            back up over a mixture of the two cases, it incorrectly assumed they
766            were both the same length.
767    
768        (b) When PCRE was configured to use the heap rather than the stack for
769            recursion during matching, it was not correctly preserving the data for
770            the other case of a UTF-8 character when checking ahead for a match
771            while processing a minimizing repeat. If the check also involved
772            matching a wide character, but failed, corruption could cause an
773            erroneous result when trying to check for a repeat of the original
774            character.
775    
776    13. Some tidying changes to the testing mechanism:
777    
778        (a) The RunTest script now detects the internal link size and whether there
779            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
780            values substituted by "configure". (The RunGrepTest script already did
781            this for UTF-8.) The configure.ac script no longer substitutes the
782            relevant variables.
783    
784        (b) The debugging options /B and /D in pcretest show the compiled bytecode
785            with length and offset values. This means that the output is different
786            for different internal link sizes. Test 2 is skipped for link sizes
787            other than 2 because of this, bypassing the problem. Unfortunately,
788            there was also a test in test 3 (the locale tests) that used /B and
789            failed for link sizes other than 2. Rather than cut the whole test out,
790            I have added a new /Z option to pcretest that replaces the length and
791            offset values with spaces. This is now used to make test 3 independent
792            of link size. (Test 2 will be tidied up later.)
793    
794    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
795        segmentation fault instead of returning the appropriate error message.
796    
797    15. In multiline mode when the newline sequence was set to "any", the pattern
798        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
799        This doesn't seem right; it now treats the CRLF combination as the line
800        ending, and so does not match in that case. It's only a pattern such as ^$
801        that would hit this one: something like ^ABC$ would have failed after \r
802        and then tried again after \r\n.
803    
804    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
805        in an attempt to make files that differ only in their line terminators
806        compare equal. This works on Linux.
807    
808    17. Under certain error circumstances pcregrep might try to free random memory
809        as it exited. This is now fixed, thanks to valgrind.
810    
811    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
812        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
813        was because its rules for how to advance for /g after matching an empty
814        string at the end of a line did not allow for this case. They now check for
815        it specially.
816    
817    20. pcretest is supposed to handle patterns and data of any length, by
818        extending its buffers when necessary. It was getting this wrong when the
819        buffer for a data line had to be extended.
820    
821    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
822        CRLF as a newline sequence.
823    
824    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
825        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
826        I have nevertheless tidied it up.
827    
828    23. Added some casts to kill warnings from HP-UX ia64 compiler.
829    
830    24. Added a man page for pcre-config.
831    
832    
833  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
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