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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 30-Apr-2011  Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
5    development is happening in the PCRE2 10.xx series.
6    
7    Version 8.38 xx-xxx-xxxx
8    ------------------------
9    
10    1.  If a group that contained a recursive back reference also contained a
11        forward reference subroutine call followed by a non-forward-reference
12        subroutine call, for example /.((?2)(?R)\1)()/, pcre2_compile() failed to
13        compile correct code, leading to undefined behaviour or an internally
14        detected error. This bug was discovered by the LLVM fuzzer.
15    
16    2.  Quantification of certain items (e.g. atomic back references) could cause
17        incorrect code to be compiled when recursive forward references were
18        involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
19        This bug was discovered by the LLVM fuzzer.
20    
21    3.  A repeated conditional group whose condition was a reference by name caused
22        a buffer overflow if there was more than one group with the given name.
23        This bug was discovered by the LLVM fuzzer.
24    
25    4.  A recursive back reference by name within a group that had the same name as
26        another group caused a buffer overflow. For example:
27        /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
28    
29    5.  A forward reference by name to a group whose number is the same as the
30        current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
31        a buffer overflow at compile time. This bug was discovered by the LLVM
32        fuzzer.
33    
34    6.  A lookbehind assertion within a set of mutually recursive subpatterns could
35        provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
36    
37    7.  Another buffer overflow bug involved duplicate named groups with a
38        reference between their definition, with a group that reset capture
39        numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
40        fixed by always allowing for more memory, even if not needed. (A proper fix
41        is implemented in PCRE2, but it involves more refactoring.)
42    
43    
44    Version 8.37 28-April-2015
45    --------------------------
46    
47    1.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
48        for those parentheses to be closed with whatever has been captured so far.
49        However, it was failing to mark any other groups between the hightest
50        capture so far and the currrent group as "unset". Thus, the ovector for
51        those groups contained whatever was previously there. An example is the
52        pattern /(x)|((*ACCEPT))/ when matched against "abcd".
53    
54    2.  If an assertion condition was quantified with a minimum of zero (an odd
55        thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
56    
57    3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
58        unrecognized modifier, a crash could occur.
59    
60    4.  An attempt to do global matching in pcretest with a zero-length ovector
61        caused a crash.
62    
63    5.  Fixed a memory leak during matching that could occur for a subpattern
64        subroutine call (recursive or otherwise) if the number of captured groups
65        that had to be saved was greater than ten.
66    
67    6.  Catch a bad opcode during auto-possessification after compiling a bad UTF
68        string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
69        UTF with NO_UTF_CHECK is documented as having an undefined outcome.
70    
71    7.  A UTF pattern containing a "not" match of a non-ASCII character and a
72        subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
73    
74    8. When a pattern is compiled, it remembers the highest back reference so that
75       when matching, if the ovector is too small, extra memory can be obtained to
76       use instead. A conditional subpattern whose condition is a check on a
77       capture having happened, such as, for example in the pattern
78       /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
79       setting the highest backreference number. This mattered only if pcre_exec()
80       was called with an ovector that was too small to hold the capture, and there
81       was no other kind of back reference (a situation which is probably quite
82       rare). The effect of the bug was that the condition was always treated as
83       FALSE when the capture could not be consulted, leading to a incorrect
84       behaviour by pcre_exec(). This bug has been fixed.
85    
86    9. A reference to a duplicated named group (either a back reference or a test
87       for being set in a conditional) that occurred in a part of the pattern where
88       PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
89       to be incorrectly calculated, leading to overwriting.
90    
91    10. A mutually recursive set of back references such as (\2)(\1) caused a
92        segfault at study time (while trying to find the minimum matching length).
93        The infinite loop is now broken (with the minimum length unset, that is,
94        zero).
95    
96    11. If an assertion that was used as a condition was quantified with a minimum
97        of zero, matching went wrong. In particular, if the whole group had
98        unlimited repetition and could match an empty string, a segfault was
99        likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
100        assertions to be quantified, but not if they are being used as conditions,
101        so the above pattern is faulted by Perl. PCRE has now been changed so that
102        it also rejects such patterns.
103    
104    12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
105        failed to allow the zero-repeat case if pcre2_exec() was called with an
106        ovector too small to capture the group.
107    
108    13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
109        Red Hat Product Security:
110    
111        (a) A crash if /K and /F were both set with the option to save the compiled
112        pattern.
113    
114        (b) Another crash if the option to print captured substrings in a callout
115        was combined with setting a null ovector, for example \O\C+ as a subject
116        string.
117    
118    14. A pattern such as "((?2){0,1999}())?", which has a group containing a
119        forward reference repeated a large (but limited) number of times within a
120        repeated outer group that has a zero minimum quantifier, caused incorrect
121        code to be compiled, leading to the error "internal error:
122        previously-checked referenced subpattern not found" when an incorrect
123        memory address was read. This bug was reported as "heap overflow",
124        discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
125        CVE-2015-2325.
126    
127    23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
128        call within a group that also contained a recursive back reference caused
129        incorrect code to be compiled. This bug was reported as "heap overflow",
130        discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
131        number CVE-2015-2326.
132    
133    24. Computing the size of the JIT read-only data in advance has been a source
134        of various issues, and new ones are still appear unfortunately. To fix
135        existing and future issues, size computation is eliminated from the code,
136        and replaced by on-demand memory allocation.
137    
138    25. A pattern such as /(?i)[A-`]/, where characters in the other case are
139        adjacent to the end of the range, and the range contained characters with
140        more than one other case, caused incorrect behaviour when compiled in UTF
141        mode. In that example, the range a-j was left out of the class.
142    
143    26. Fix JIT compilation of conditional blocks, which assertion
144        is converted to (*FAIL). E.g: /(?(?!))/.
145    
146    27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
147        discovered by the LLVM fuzzer.
148    
149    28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
150        when this assertion was used as a condition, for example (?(?!)a|b). In
151        pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
152        error about an unsupported item.
153    
154    29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
155        possessification code could take exponential time to complete. A recursion
156        depth limit of 1000 has been imposed to limit the resources used by this
157        optimization.
158    
159    30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
160        such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
161        because \S ensures they are all in the class. The code for doing this was
162        interacting badly with the code for computing the amount of space needed to
163        compile the pattern, leading to a buffer overflow. This bug was discovered
164        by the LLVM fuzzer.
165    
166    31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
167        other kinds of group caused stack overflow at compile time. This bug was
168        discovered by the LLVM fuzzer.
169    
170    32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
171        between a subroutine call and its quantifier was incorrectly compiled,
172        leading to buffer overflow or other errors. This bug was discovered by the
173        LLVM fuzzer.
174    
175    33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
176        assertion after (?(. The code was failing to check the character after
177        (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
178        was discovered by the LLVM fuzzer.
179    
180    34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
181        a fixed maximum following a group that contains a subroutine reference was
182        incorrectly compiled and could trigger buffer overflow. This bug was
183        discovered by the LLVM fuzzer.
184    
185    35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
186        caused a stack overflow instead of the diagnosis of a non-fixed length
187        lookbehind assertion. This bug was discovered by the LLVM fuzzer.
188    
189    36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
190        (e.g. /(?<=\Ka)/) could make pcregrep loop.
191    
192    37. There was a similar problem to 36 in pcretest for global matches.
193    
194    38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
195        and a subsequent item in the pattern caused a non-match, backtracking over
196        the repeated \X did not stop, but carried on past the start of the subject,
197        causing reference to random memory and/or a segfault. There were also some
198        other cases where backtracking after \C could crash. This set of bugs was
199        discovered by the LLVM fuzzer.
200    
201    39. The function for finding the minimum length of a matching string could take
202        a very long time if mutual recursion was present many times in a pattern,
203        for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
204        method has been implemented. This infelicity was discovered by the LLVM
205        fuzzer.
206    
207    40. Static linking against the PCRE library using the pkg-config module was
208        failing on missing pthread symbols.
209    
210    
211    Version 8.36 26-September-2014
212    ------------------------------
213    
214    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
215        -Wmissing-field-initializers and -Wunused-parameter.
216    
217    2.  The tests for quantifiers being too big (greater than 65535) were being
218        applied after reading the number, and stupidly assuming that integer
219        overflow would give a negative number. The tests are now applied as the
220        numbers are read.
221    
222    3.  Tidy code in pcre_exec.c where two branches that used to be different are
223        now the same.
224    
225    4.  The JIT compiler did not generate match limit checks for certain
226        bracketed expressions with quantifiers. This may lead to exponential
227        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
228        issue should be resolved now.
229    
230    5.  Fixed an issue, which occures when nested alternatives are optimized
231        with table jumps.
232    
233    6.  Inserted two casts and changed some ints to size_t in the light of some
234        reported 64-bit compiler warnings (Bugzilla 1477).
235    
236    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
237        an empty string, which sometimes were behaving incorrectly in the
238        interpreter (though correctly in the JIT matcher). This pcretest input is
239        an example:
240    
241          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
242          NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
243    
244        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
245        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
246        for an empty string was breaking the inner loop and carrying on at a lower
247        level, when possessive repeated groups should always return to a higher
248        level as they have no backtrack points in them. The empty string test now
249        occurs at the outer level.
250    
251    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
252        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
253    
254    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
255        doesn't).
256    
257    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
258        to hold a pattern to be incorrectly computed (too small) when there were
259        named back references to duplicated names. This could cause "internal
260        error: code overflow" or "double free or corruption" or other memory
261        handling errors.
262    
263    11. When named subpatterns had the same prefixes, back references could be
264        confused. For example, in this pattern:
265    
266          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
267    
268        the reference to 'Name' was incorrectly treated as a reference to a
269        duplicate name.
270    
271    12. A pattern such as /^s?c/mi8 where the optional character has more than
272        one "other case" was incorrectly compiled such that it would only try to
273        match starting at "c".
274    
275    13. When a pattern starting with \s was studied, VT was not included in the
276        list of possible starting characters; this should have been part of the
277        8.34/18 patch.
278    
279    14. If a character class started [\Qx]... where x is any character, the class
280        was incorrectly terminated at the ].
281    
282    15. If a pattern that started with a caseless match for a character with more
283        than one "other case" was studied, PCRE did not set up the starting code
284        unit bit map for the list of possible characters. Now it does. This is an
285        optimization improvement, not a bug fix.
286    
287    16. The Unicode data tables have been updated to Unicode 7.0.0.
288    
289    17. Fixed a number of memory leaks in pcregrep.
290    
291    18. Avoid a compiler warning (from some compilers) for a function call with
292        a cast that removes "const" from an lvalue by using an intermediate
293        variable (to which the compiler does not object).
294    
295    19. Incorrect code was compiled if a group that contained an internal recursive
296        back reference was optional (had quantifier with a minimum of zero). This
297        example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
298        caused segmentation faults because of stack overflows at compile time.
299    
300    20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
301        group that is quantified with an indefinite repeat, caused a compile-time
302        loop which used up all the system stack and provoked a segmentation fault.
303        This was not the same bug as 19 above.
304    
305    21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
306        Patch by Mike Frysinger.
307    
308    
309    Version 8.35 04-April-2014
310    --------------------------
311    
312    1.  A new flag is set, when property checks are present in an XCLASS.
313        When this flag is not set, PCRE can perform certain optimizations
314        such as studying these XCLASS-es.
315    
316    2.  The auto-possessification of character sets were improved: a normal
317        and an extended character set can be compared now. Furthermore
318        the JIT compiler optimizes more character set checks.
319    
320    3.  Got rid of some compiler warnings for potentially uninitialized variables
321        that show up only when compiled with -O2.
322    
323    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
324        of a match later then the end of the match. The pcretest program was not
325        handling the case sensibly - it was outputting from the start to the next
326        binary zero. It now reports this situation in a message, and outputs the
327        text from the end to the start.
328    
329    5.  Fast forward search is improved in JIT. Instead of the first three
330        characters, any three characters with fixed position can be searched.
331        Search order: first, last, middle.
332    
333    6.  Improve character range checks in JIT. Characters are read by an inprecise
334        function now, which returns with an unknown value if the character code is
335        above a certain threshold (e.g: 256). The only limitation is that the value
336        must be bigger than the threshold as well. This function is useful when
337        the characters above the threshold are handled in the same way.
338    
339    7.  The macros whose names start with RAWUCHAR are placeholders for a future
340        mode in which only the bottom 21 bits of 32-bit data items are used. To
341        make this more memorable for those maintaining the code, the names have
342        been changed to start with UCHAR21, and an extensive comment has been added
343        to their definition.
344    
345    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
346        to the export list in Makefile.am (they were accidentally omitted from the
347        8.34 tarball).
348    
349    9.  The informational output from pcretest used the phrase "starting byte set"
350        which is inappropriate for the 16-bit and 32-bit libraries. As the output
351        for "first char" and "need char" really means "non-UTF-char", I've changed
352        "byte" to "char", and slightly reworded the output. The documentation about
353        these values has also been (I hope) clarified.
354    
355    10. Another JIT related optimization: use table jumps for selecting the correct
356        backtracking path, when more than four alternatives are present inside a
357        bracket.
358    
359    11. Empty match is not possible, when the minimum length is greater than zero,
360        and there is no \K in the pattern. JIT should avoid empty match checks in
361        such cases.
362    
363    12. In a caseless character class with UCP support, when a character with more
364        than one alternative case was not the first character of a range, not all
365        the alternative cases were added to the class. For example, s and \x{17f}
366        are both alternative cases for S: the class [RST] was handled correctly,
367        but [R-T] was not.
368    
369    13. The configure.ac file always checked for pthread support when JIT was
370        enabled. This is not used in Windows, so I have put this test inside a
371        check for the presence of windows.h (which was already tested for).
372    
373    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
374        The algorithm provides a way to skip certain starting offsets, and usually
375        faster than linear prefix searches.
376    
377    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
378        as for 'fr_FR' and 'french'. For some reason, however, it then used the
379        Windows-specific input and output files, which have 'french' screwed in.
380        So this could never have worked. One of the problems with locales is that
381        they aren't always the same. I have now updated RunTest so that it checks
382        the output of the locale test (test 3) against three different output
383        files, and it allows the test to pass if any one of them matches. With luck
384        this should make the test pass on some versions of Solaris where it was
385        failing. Because of the uncertainty, the script did not used to stop if
386        test 3 failed; it now does. If further versions of a French locale ever
387        come to light, they can now easily be added.
388    
389    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
390        there was a message during ./configure, but it did not stop. This now
391        provokes an error. The invalid example in README has been corrected.
392        If a value less than the minimum is given, the minimum value has always
393        been used, but now a warning is given.
394    
395    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
396        was a bug in the test system, which is now fixed. Also, the list of various
397        configurations that are tested for each release did not have one with both
398        16/32 bits and --enable-bar-anycrlf. It now does.
399    
400    18. pcretest was missing "-C bsr" for displaying the \R default setting.
401    
402    19. Little endian PowerPC systems are supported now by the JIT compiler.
403    
404    20. The fast forward newline mechanism could enter to an infinite loop on
405        certain invalid UTF-8 input. Although we don't support these cases
406        this issue can be fixed by a performance optimization.
407    
408    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
409        not take account if existing stack usage. There is now a new global
410        variable called pcre_stack_guard that can be set to point to an external
411        function to check stack availability. It is called at the start of
412        processing every parenthesized group.
413    
414    22. A typo in the code meant that in ungreedy mode the max/min qualifier
415        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
416        not match "ab".
417    
418    23. When UTF was disabled, the JIT program reported some incorrect compile
419        errors. These messages are silenced now.
420    
421    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
422        compiler.
423    
424    25. Change all the temporary files used in RunGrepTest to be different to those
425        used by RunTest so that the tests can be run simultaneously, for example by
426        "make -j check".
427    
428    
429    Version 8.34 15-December-2013
430    -----------------------------
431    
432    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
433        executable memory. Patch inspired by Carsten Klein.
434    
435    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
436        this macro is never tested and has no effect, because the work to support
437        coverage involves only compiling and linking options and special targets in
438        the Makefile. The comment in config.h implied that defining the macro would
439        enable coverage support, which is totally false. There was also support for
440        setting this macro in the CMake files (my fault, I just copied it from
441        configure). SUPPORT_GCOV has now been removed.
442    
443    3.  Make a small performance improvement in strlen16() and strlen32() in
444        pcretest.
445    
446    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
447        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
448        these cases). There was also one in pcretest.c.
449    
450    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
451    
452    6.  In UTF mode, the code for checking whether a group could match an empty
453        string (which is used for indefinitely repeated groups to allow for
454        breaking an infinite loop) was broken when the group contained a repeated
455        negated single-character class with a character that occupied more than one
456        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
457        UTF-8 mode). The effect was undefined: the group might or might not be
458        deemed as matching an empty string, or the program might have crashed.
459    
460    7.  The code for checking whether a group could match an empty string was not
461        recognizing that \h, \H, \v, \V, and \R must match a character.
462    
463    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
464        an empty string. If it can, pcretest shows this in its information output.
465    
466    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
467        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
468        matched by pcre_exec() without using JIT:
469    
470        (a) If the rest of the pattern did not match after a maximal run of
471            grapheme clusters, the code for backing up to try with fewer of them
472            did not always back up over a full grapheme when characters that do not
473            have the modifier quality were involved, e.g. Hangul syllables.
474    
475        (b) If the match point in a subject started with modifier character, and
476            there was no match, the code could incorrectly back up beyond the match
477            point, and potentially beyond the first character in the subject,
478            leading to a segfault or an incorrect match result.
479    
480    10. A conditional group with an assertion condition could lead to PCRE
481        recording an incorrect first data item for a match if no other first data
482        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
483        first data item, and therefore matched "ca" after "c" instead of at the
484        start.
485    
486    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
487        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
488    
489    12. The source of pcregrep now includes z/OS-specific code so that it can be
490        compiled for z/OS as part of the special z/OS distribution.
491    
492    13. Added the -T and -TM options to pcretest.
493    
494    14. The code in pcre_compile.c for creating the table of named capturing groups
495        has been refactored. Instead of creating the table dynamically during the
496        actual compiling pass, the information is remembered during the pre-compile
497        pass (on the stack unless there are more than 20 named groups, in which
498        case malloc() is used) and the whole table is created before the actual
499        compile happens. This has simplified the code (it is now nearly 150 lines
500        shorter) and prepared the way for better handling of references to groups
501        with duplicate names.
502    
503    15. A back reference to a named subpattern when there is more than one of the
504        same name now checks them in the order in which they appear in the pattern.
505        The first one that is set is used for the reference. Previously only the
506        first one was inspected. This change makes PCRE more compatible with Perl.
507    
508    16. Unicode character properties were updated from Unicode 6.3.0.
509    
510    17. The compile-time code for auto-possessification has been refactored, based
511        on a patch by Zoltan Herczeg. It now happens after instead of during
512        compilation. The code is cleaner, and more cases are handled. The option
513        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
514        options in pcretest are provided to set it. It can also be set by
515        (*NO_AUTO_POSSESS) at the start of a pattern.
516    
517    18. The character VT has been added to the default ("C" locale) set of
518        characters that match \s and are generally treated as white space,
519        following this same change in Perl 5.18. There is now no difference between
520        "Perl space" and "POSIX space". Whether VT is treated as white space in
521        other locales depends on the locale.
522    
523    19. The code for checking named groups as conditions, either for being set or
524        for being recursed, has been refactored (this is related to 14 and 15
525        above). Processing unduplicated named groups should now be as fast at
526        numerical groups, and processing duplicated groups should be faster than
527        before.
528    
529    20. Two patches to the CMake build system, by Alexander Barkov:
530    
531          (1) Replace the "source" command by "." in CMakeLists.txt because
532              "source" is a bash-ism.
533    
534          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
535              without these the CMake build does not work on Solaris.
536    
537    21. Perl has changed its handling of \8 and \9. If there is no previously
538        encountered capturing group of those numbers, they are treated as the
539        literal characters 8 and 9 instead of a binary zero followed by the
540        literals. PCRE now does the same.
541    
542    22. Following Perl, added \o{} to specify codepoints in octal, making it
543        possible to specify values greater than 0777 and also making them
544        unambiguous.
545    
546    23. Perl now gives an error for missing closing braces after \x{... instead of
547        treating the string as literal. PCRE now does the same.
548    
549    24. RunTest used to grumble if an inappropriate test was selected explicitly,
550        but just skip it when running all tests. This make it awkward to run ranges
551        of tests when one of them was inappropriate. Now it just skips any
552        inappropriate tests, as it always did when running all tests.
553    
554    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
555        character types such as \d or \w, too many callouts were inserted, and the
556        data that they returned was rubbish.
557    
558    26. In UCP mode, \s was not matching two of the characters that Perl matches,
559        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
560        were matched by \h. The code has now been refactored so that the lists of
561        the horizontal and vertical whitespace characters used for \h and \v (which
562        are defined only in one place) are now also used for \s.
563    
564    27. Add JIT support for the 64 bit TileGX architecture.
565        Patch by Jiong Wang (Tilera Corporation).
566    
567    28. Possessive quantifiers for classes (both explicit and automatically
568        generated) now use special opcodes instead of wrapping in ONCE brackets.
569    
570    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
571        (because it's meaningless), this was not happening when PCRE_CASELESS was
572        set. Not wrong, but inefficient.
573    
574    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
575        properties for \w, \d, etc) is present in a test regex. Otherwise if the
576        test contains no characters greater than 255, Perl doesn't realise it
577        should be using Unicode semantics.
578    
579    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
580        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
581        does in Unicode mode.
582    
583    32. Added the "forbid" facility to pcretest so that putting tests into the
584        wrong test files can sometimes be quickly detected.
585    
586    33. There is now a limit (default 250) on the depth of nesting of parentheses.
587        This limit is imposed to control the amount of system stack used at compile
588        time. It can be changed at build time by --with-parens-nest-limit=xxx or
589        the equivalent in CMake.
590    
591    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
592        errors. Perl warns for these when in warning mode, but PCRE has no facility
593        for giving warnings.
594    
595    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
596        However, this was not working for (?!) because it is optimized to (*FAIL),
597        for which PCRE does not allow quantifiers. The optimization is now disabled
598        when a quantifier follows (?!). I can't see any use for this, but it makes
599        things uniform.
600    
601    36. Perl no longer allows group names to start with digits, so I have made this
602        change also in PCRE. It simplifies the code a bit.
603    
604    37. In extended mode, Perl ignores spaces before a + that indicates a
605        possessive quantifier. PCRE allowed a space before the quantifier, but not
606        before the possessive +. It now does.
607    
608    38. The use of \K (reset reported match start) within a repeated possessive
609        group such as (a\Kb)*+ was not working.
610    
611    40. Document that the same character tables must be used at compile time and
612        run time, and that the facility to pass tables to pcre_exec() and
613        pcre_dfa_exec() is for use only with saved/restored patterns.
614    
615    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
616        features for Builds with MSVC:
617    
618        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
619           builds). The .rc files can be used to set FileDescription and many other
620           attributes.
621    
622        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
623           This allows higher-level build scripts which want .pdb files to avoid
624           hard-coding the exact files needed."
625    
626    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
627        mean "start of word" and "end of word", respectively, as a transition aid.
628    
629    43. A minimizing repeat of a class containing codepoints greater than 255 in
630        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
631        compiled to use the heap for recursion.
632    
633    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
634        is configured.
635    
636    
637    Version 8.33 28-May-2013
638    ------------------------
639    
640    1.  Added 'U' to some constants that are compared to unsigned integers, to
641        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
642        variables that are added to signed variables, to ensure the result is
643        signed and can be negated.
644    
645    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
646        CMake config files.
647    
648    3.  Revise the creation of config.h.generic so that all boolean macros are
649        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
650        overriding via -D on the command line possible.
651    
652    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
653        to unsigned int is reported to make a quite noticeable speed difference in
654        a specific Windows environment. Testing on Linux did also appear to show
655        some benefit (and it is clearly not harmful). Also fixed the definition of
656        Xop which should be unsigned.
657    
658    5.  Related to (4), changing the definition of the intermediate variable cc
659        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
660        improvements.
661    
662    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
663        unnecessary spaces.
664    
665    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
666        and later.
667    
668    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
669    
670    9.  Optimizing fast_forward_start_bits in JIT.
671    
672    10. Adding support for callouts in JIT, and fixing some issues revealed
673        during this work. Namely:
674    
675        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
676    
677        (b) Minimum length was not checked before the matching is started.
678    
679    11. The value of capture_last that is passed to callouts was incorrect in some
680        cases when there was a capture on one path that was subsequently abandoned
681        after a backtrack. Also, the capture_last value is now reset after a
682        recursion, since all captures are also reset in this case.
683    
684    12. The interpreter no longer returns the "too many substrings" error in the
685        case when an overflowing capture is in a branch that is subsequently
686        abandoned after a backtrack.
687    
688    13. In the pathological case when an offset vector of size 2 is used, pcretest
689        now prints out the matched string after a yield of 0 or 1.
690    
691    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
692        Only supported by the JIT compiler at the moment.
693    
694    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
695    
696    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
697        offset of the starting point of the matching process, provided the offsets
698        vector is large enough.
699    
700    17. The \A escape now records a lookbehind value of 1, though its execution
701        does not actually inspect the previous character. This is to ensure that,
702        in partial multi-segment matching, at least one character from the old
703        segment is retained when a new segment is processed. Otherwise, if there
704        are no lookbehinds in the pattern, \A might match incorrectly at the start
705        of a new segment.
706    
707    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
708    
709    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
710        gives some modest performance improvement in 8-bit mode.
711    
712    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
713        be expressed in certain programming languages using Universal Character
714        Names.
715    
716    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
717        which points out that "non characters" are not "characters that may not
718        appear in Unicode strings" but rather "characters that are reserved for
719        internal use and have only local meaning".
720    
721    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
722        there was a conditional group that depended on an assertion, if the
723        assertion was false, the callout that immediately followed the alternation
724        in the condition was skipped when pcre_exec() was used for matching.
725    
726    23. Allow an explicit callout to be inserted before an assertion that is the
727        condition for a conditional group, for compatibility with automatic
728        callouts, which always insert a callout at this point.
729    
730    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
731        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
732    
733    25. (*PRUNE) is now supported by the JIT compiler.
734    
735    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
736    
737    27. Fix the case where there are two or more SKIPs with arguments that may be
738        ignored.
739    
740    28. (*SKIP) is now supported by the JIT compiler.
741    
742    29. (*THEN) is now supported by the JIT compiler.
743    
744    30. Update RunTest with additional test selector options.
745    
746    31. The way PCRE handles backtracking verbs has been changed in two ways.
747    
748        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
749        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
750        backtracking. In some cases this makes it more Perl-compatible, but Perl's
751        rather obscure rules do not always do the same thing.
752    
753        (2) Previously, backtracking verbs were confined within assertions. This is
754        no longer the case for positive assertions, except for (*ACCEPT). Again,
755        this sometimes improves Perl compatibility, and sometimes does not.
756    
757    32. A number of tests that were in test 2 because Perl did things differently
758        have been moved to test 1, because either Perl or PCRE has changed, and
759        these tests are now compatible.
760    
761    32. Backtracking control verbs are now handled in the same way in JIT and
762        interpreter.
763    
764    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
765        contained a forward subroutine reference caused a compile error.
766    
767    34. Auto-detect and optimize limited repetitions in JIT.
768    
769    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
770        blocking (*UTF) etc.
771    
772    36. In the interpreter, maximizing pattern repetitions for characters and
773        character types now use tail recursion, which reduces stack usage.
774    
775    37. The value of the max lookbehind was not correctly preserved if a compiled
776        and saved regex was reloaded on a host of different endianness.
777    
778    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
779        of the compiled pattern block, expand the flags field from 16 to 32 bits
780        because it was almost full.
781    
782    39. Try madvise first before posix_madvise.
783    
784    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
785        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
786        original change locked out all matches of empty strings. This has been
787        changed so that one match of an empty string per line is recognized.
788        Subsequent searches on the same line (for colouring or for --only-matching,
789        for example) do not recognize empty strings.
790    
791    41. Applied a user patch to fix a number of spelling mistakes in comments.
792    
793    42. Data lines longer than 65536 caused pcretest to crash.
794    
795    43. Clarified the data type for length and startoffset arguments for pcre_exec
796        and pcre_dfa_exec in the function-specific man pages, where they were
797        explicitly stated to be in bytes, never having been updated. I also added
798        some clarification to the pcreapi man page.
799    
800    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
801        a segmentation fault.
802    
803    
804    Version 8.32 30-November-2012
805    -----------------------------
806    
807    1.  Improved JIT compiler optimizations for first character search and single
808        character iterators.
809    
810    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
811        Patch by Daniel Richard G.
812    
813    3.  Single character iterator optimizations in the JIT compiler.
814    
815    4.  Improved JIT compiler optimizations for character ranges.
816    
817    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
818        Reported by Giuseppe D'Angelo.
819    
820    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
821        of a line, was being set incorrectly in cases where .* appeared inside
822        atomic brackets at the start of a pattern, or where there was a subsequent
823        *PRUNE or *SKIP.
824    
825    7.  Improved instruction cache flush for POWER/PowerPC.
826        Patch by Daniel Richard G.
827    
828    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
829        grep:
830    
831        (a) There is now no limit to the number of patterns to be matched.
832    
833        (b) An error is given if a pattern is too long.
834    
835        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
836            are now supported.
837    
838        (d) --exclude-from and --include-from (multiple use) have been added.
839    
840        (e) Exclusions and inclusions now apply to all files and directories, not
841            just to those obtained from scanning a directory recursively.
842    
843        (f) Multiple uses of -f and --file-list are now supported.
844    
845        (g) In a Windows environment, the default for -d has been changed from
846            "read" (the GNU grep default) to "skip", because otherwise the presence
847            of a directory in the file list provokes an error.
848    
849        (h) The documentation has been revised and clarified in places.
850    
851    9.  Improve the matching speed of capturing brackets.
852    
853    10. Changed the meaning of \X so that it now matches a Unicode extended
854        grapheme cluster.
855    
856    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
857        out POSIX threads when JIT support is configured.
858    
859    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
860    
861    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
862        structure could go wrong in environments where size_t is not the same size
863        as int.
864    
865    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
866        set.
867    
868    15. The EBCDIC support had decayed; later updates to the code had included
869        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
870        general tidy up of EBCDIC-related issues, and the documentation was also
871        not quite right. There is now a test that can be run on ASCII systems to
872        check some of the EBCDIC-related things (but is it not a full test).
873    
874    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
875        in a small tidy to the code.
876    
877    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
878    
879    18. If the --only-matching (-o) option in pcregrep is specified multiple
880        times, each one causes appropriate output. For example, -o1 -o2 outputs the
881        substrings matched by the 1st and 2nd capturing parentheses. A separating
882        string can be specified by --om-separator (default empty).
883    
884    19. Improving the first n character searches.
885    
886    20. Turn case lists for horizontal and vertical white space into macros so that
887        they are defined only once.
888    
889    21. This set of changes together give more compatible Unicode case-folding
890        behaviour for characters that have more than one other case when UCP
891        support is available.
892    
893        (a) The Unicode property table now has offsets into a new table of sets of
894            three or more characters that are case-equivalent. The MultiStage2.py
895            script that generates these tables (the pcre_ucd.c file) now scans
896            CaseFolding.txt instead of UnicodeData.txt for character case
897            information.
898    
899        (b) The code for adding characters or ranges of characters to a character
900            class has been abstracted into a generalized function that also handles
901            case-independence. In UTF-mode with UCP support, this uses the new data
902            to handle characters with more than one other case.
903    
904        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
905            whose other case is greater than 256 are now correctly matched
906            caselessly. Previously, the high codepoint matched the low one, but not
907            vice versa.
908    
909        (d) The processing of \h, \H, \v, and \ in character classes now makes use
910            of the new class addition function, using character lists defined as
911            macros alongside the case definitions of 20 above.
912    
913        (e) Caseless back references now work with characters that have more than
914            one other case.
915    
916        (f) General caseless matching of characters with more than one other case
917            is supported.
918    
919    22. Unicode character properties were updated from Unicode 6.2.0
920    
921    23. Improved CMake support under Windows. Patch by Daniel Richard G.
922    
923    24. Add support for 32-bit character strings, and UTF-32
924    
925    25. Major JIT compiler update (code refactoring and bugfixing).
926        Experimental Sparc 32 support is added.
927    
928    26. Applied a modified version of Daniel Richard G's patch to create
929        pcre.h.generic and config.h.generic by "make" instead of in the
930        PrepareRelease script.
931    
932    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
933        pcre_compile.c when checking for a zero character.
934    
935    28. Introducing a native interface for JIT. Through this interface, the compiled
936        machine code can be directly executed. The purpose of this interface is to
937        provide fast pattern matching, so several sanity checks are not performed.
938        However, feature tests are still performed. The new interface provides
939        1.4x speedup compared to the old one.
940    
941    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
942        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
943        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
944    
945    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
946        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
947        the "old" RFC 2279). Instead, it ended up passing a negative length to
948        pcre_exec().
949    
950    31. Add support for GCC's visibility feature to hide internal functions.
951    
952    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
953        "unknown -C option" after outputting 0 or 1.
954    
955    33. There is now support for generating a code coverage report for the test
956        suite in environments where gcc is the compiler and lcov is installed. This
957        is mainly for the benefit of the developers.
958    
959    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
960        unaddressable using valgrind annotations, allowing valgrind to detect
961        invalid memory accesses. This is mainly for the benefit of the developers.
962    
963    25. (*UTF) can now be used to start a pattern in any of the three libraries.
964    
965    26. Give configure error if --enable-cpp but no C++ compiler found.
966    
967    
968    Version 8.31 06-July-2012
969    -------------------------
970    
971    1.  Fixing a wrong JIT test case and some compiler warnings.
972    
973    2.  Removed a bashism from the RunTest script.
974    
975    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
976        to unsigned type, result still unsigned" that was given by an MS compiler
977        on encountering the code "-sizeof(xxx)".
978    
979    4.  Partial matching support is added to the JIT compiler.
980    
981    5.  Fixed several bugs concerned with partial matching of items that consist
982        of more than one character:
983    
984        (a) /^(..)\1/ did not partially match "aba" because checking references was
985            done on an "all or nothing" basis. This also applied to repeated
986            references.
987    
988        (b) \R did not give a hard partial match if \r was found at the end of the
989            subject.
990    
991        (c) \X did not give a hard partial match after matching one or more
992            characters at the end of the subject.
993    
994        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
995            a partial match for the string "\r".
996    
997        (e) When newline was set to CRLF, the metacharacter "." did not recognize
998            a partial match for a CR character at the end of the subject string.
999    
1000    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1001        running pcretest, the text "(JIT)" added to the output whenever JIT is
1002        actually used to run the match.
1003    
1004    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
1005        or /S+[+] with a digit between 1 and 7.
1006    
1007    8.  OP_NOT now supports any UTF character not just single-byte ones.
1008    
1009    9.  (*MARK) control verb is now supported by the JIT compiler.
1010    
1011    10. The command "./RunTest list" lists the available tests without actually
1012        running any of them. (Because I keep forgetting what they all are.)
1013    
1014    11. Add PCRE_INFO_MAXLOOKBEHIND.
1015    
1016    12. Applied a (slightly modified) user-supplied patch that improves performance
1017        when the heap is used for recursion (compiled with --disable-stack-for-
1018        recursion). Instead of malloc and free for each heap frame each time a
1019        logical recursion happens, frames are retained on a chain and re-used where
1020        possible. This sometimes gives as much as 30% improvement.
1021    
1022    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1023        call.
1024    
1025    14. As documented, (*COMMIT) is now confined to within a positive assertion.
1026    
1027    15. It is now possible to link pcretest with libedit as an alternative to
1028        libreadline.
1029    
1030    16. (*COMMIT) control verb is now supported by the JIT compiler.
1031    
1032    17. The Unicode data tables have been updated to Unicode 6.1.0.
1033    
1034    18. Added --file-list option to pcregrep.
1035    
1036    19. Added binary file support to pcregrep, including the -a, --binary-files,
1037        -I, and --text options.
1038    
1039    20. The madvise function is renamed for posix_madvise for QNX compatibility
1040        reasons. Fixed by Giuseppe D'Angelo.
1041    
1042    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1043    
1044    22. Changed the option for creating symbolic links for 16-bit man pages from
1045        -s to -sf so that re-installing does not cause issues.
1046    
1047    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1048    
1049    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1050        matches in certain environments (the workspace was not being correctly
1051        retained). Also added to pcre_dfa_exec() a simple plausibility check on
1052        some of the workspace data at the beginning of a restart.
1053    
1054    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1055        was not doing so when it should - probably a typo introduced by SVN 528
1056        (change 8.10/14).
1057    
1058    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1059        \w+ when the character tables indicated that \x{c4} was a word character.
1060        There were several related cases, all because the tests for doing a table
1061        lookup were testing for characters less than 127 instead of 255.
1062    
1063    27. If a pattern contains capturing parentheses that are not used in a match,
1064        their slots in the ovector are set to -1. For those that are higher than
1065        any matched groups, this happens at the end of processing. In the case when
1066        there were back references that the ovector was too small to contain
1067        (causing temporary malloc'd memory to be used during matching), and the
1068        highest capturing number was not used, memory off the end of the ovector
1069        was incorrectly being set to -1. (It was using the size of the temporary
1070        memory instead of the true size.)
1071    
1072    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1073        ovector size, it uses memory at the end of the block that it has got.
1074    
1075    29. Check for an overlong MARK name and give an error at compile time. The
1076        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1077    
1078    30. JIT compiler update.
1079    
1080    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1081        Rill for the patch.
1082    
1083    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1084    
1085    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1086    
1087    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1088        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1089        was enabled.
1090    
1091    35. Improve JIT code generation for greedy plus quantifier.
1092    
1093    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1094        1 to "aa" instead of to an empty string. The bug affected repeated groups
1095        that could potentially match an empty string.
1096    
1097    37. Optimizing single character iterators in JIT.
1098    
1099    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1100        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1101        codepoints that are too big for the mode are faulted, and in a UTF mode,
1102        disallowed codepoints are also faulted.
1103    
1104    39. If PCRE was compiled with UTF support, in three places in the DFA
1105        matcher there was code that should only have been obeyed in UTF mode, but
1106        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1107        processing when bytes with values greater than 127 were present. In 16-bit
1108        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1109        both cases the values are those that cannot be the first data item in a UTF
1110        character. The three items that might have provoked this were recursions,
1111        possessively repeated groups, and atomic groups.
1112    
1113    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1114        and pcregrep, because some OS require shared objects to be explicitly
1115        passed to ld, causing the link step to fail if they are not.
1116    
1117    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1118        mode, patterns that started with \h* or \R* might be incorrectly matched.
1119    
1120    
1121    Version 8.30 04-February-2012
1122    -----------------------------
1123    
1124    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
1125        name is defined in ctype.h.
1126    
1127    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
1128        only in quite long subpatterns.
1129    
1130    3.  Removed the function pcre_info(), which has been obsolete and deprecated
1131        since it was replaced by pcre_fullinfo() in February 2000.
1132    
1133    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
1134        match a (*MARK), and the match failed at the start of the subject, a
1135        reference to memory before the start of the subject could occur. This bug
1136        was introduced by fix 17 of release 8.21.
1137    
1138    5.  A reference to an unset group with zero minimum repetition was giving
1139        totally wrong answers (in non-JavaScript-compatibility mode). For example,
1140        /(another)?(\1?)test/ matched against "hello world test". This bug was
1141        introduced in release 8.13.
1142    
1143    6.  Add support for 16-bit character strings (a large amount of work involving
1144        many changes and refactorings).
1145    
1146    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1147        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1148        from a file.
1149    
1150    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1151        rounding is not applied in this particular case).
1152    
1153    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1154        if they appear, or are escaped, in patterns.
1155    
1156    10. Get rid of a number of -Wunused-but-set-variable warnings.
1157    
1158    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1159        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1160        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1161        also returns the mark "x". This bug applied to capturing parentheses,
1162        non-capturing parentheses, and atomic parentheses. It also applied to some
1163        assertions.
1164    
1165    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1166        information out of configure.ac instead of relying on pcre.h.generic, which
1167        is not stored in the repository.
1168    
1169    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1170        -lreadline.
1171    
1172    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1173    
1174    15. Applied Graycode's patch to put the top-level frame on the stack rather
1175        than the heap when not using the stack for recursion. This gives a
1176        performance improvement in many cases when recursion is not deep.
1177    
1178    16. Experimental code added to "pcretest -C" to output the stack frame size.
1179    
1180    
1181    Version 8.21 12-Dec-2011
1182    ------------------------
1183    
1184    1.  Updating the JIT compiler.
1185    
1186    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1187        are added as well.
1188    
1189    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1190        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1191        calling _pcre_jit_exec. Some extra comments are added.
1192    
1193    4.  (*MARK) settings inside atomic groups that do not contain any capturing
1194        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1195        was introduced by change 18 for 8.20.
1196    
1197    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1198        ECMA-262 standard.
1199    
1200    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1201        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1202        This bug was probably introduced by change 9 of 8.13.
1203    
1204    7.  While fixing 6 above, I noticed that a number of other items were being
1205        incorrectly rejected as "not fixed length". This arose partly because newer
1206        opcodes had not been added to the fixed-length checking code. I have (a)
1207        corrected the bug and added tests for these items, and (b) arranged for an
1208        error to occur if an unknown opcode is encountered while checking for fixed
1209        length instead of just assuming "not fixed length". The items that were
1210        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1211        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1212        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1213    
1214    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1215        being incorrectly compiled and would have given unpredicatble results.
1216    
1217    9.  A possessively repeated subpattern with minimum repeat count greater than
1218        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1219        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1220        the first (A) could occur when it should not.
1221    
1222    10. Add a cast and remove a redundant test from the code.
1223    
1224    11. JIT should use pcre_malloc/pcre_free for allocation.
1225    
1226    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1227        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1228        is anything other than /usr, -L is still shown).
1229    
1230    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1231    
1232    14. Perl does not support \N without a following name in a [] class; PCRE now
1233        also gives an error.
1234    
1235    15. If a forward reference was repeated with an upper limit of around 2000,
1236        it caused the error "internal error: overran compiling workspace". The
1237        maximum number of forward references (including repeats) was limited by the
1238        internal workspace, and dependent on the LINK_SIZE. The code has been
1239        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1240        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1241        of around 200,000 forward references. While doing this, I also speeded up
1242        the filling in of repeated forward references.
1243    
1244    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1245        incorrectly expecting the subject to contain another "a" after the start.
1246    
1247    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1248        in the match, the SKIP should be ignored. This was not happening; instead
1249        the SKIP was being treated as NOMATCH. For patterns such as
1250        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1251        tested.
1252    
1253    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1254        now much more compatible with Perl, in particular in cases where the result
1255        is a non-match for a non-anchored pattern. For example, if
1256        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1257        "m", where previously it did not return a name. A side effect of this
1258        change is that for partial matches, the last encountered mark name is
1259        returned, as for non matches. A number of tests that were previously not
1260        Perl-compatible have been moved into the Perl-compatible test files. The
1261        refactoring has had the pleasing side effect of removing one argument from
1262        the match() function, thus reducing its stack requirements.
1263    
1264    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1265        subsequent uses of /S (without +) incorrectly behaved like /S+.
1266    
1267    21. Retrieve executable code size support for the JIT compiler and fixing
1268        some warnings.
1269    
1270    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1271        not work when the shorter character appeared right at the end of the
1272        subject string.
1273    
1274    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1275        systems.
1276    
1277    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1278        output it when the /M option is used in pcretest.
1279    
1280    25. The CheckMan script was not being included in the distribution. Also, added
1281        an explicit "perl" to run Perl scripts from the PrepareRelease script
1282        because this is reportedly needed in Windows.
1283    
1284    26. If study data was being save in a file and studying had not found a set of
1285        "starts with" bytes for the pattern, the data written to the file (though
1286        never used) was taken from uninitialized memory and so caused valgrind to
1287        complain.
1288    
1289    27. Updated RunTest.bat as provided by Sheri Pierce.
1290    
1291    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1292    
1293    29. Computation of memory usage for the table of capturing group names was
1294        giving an unnecessarily large value.
1295    
1296    
1297    Version 8.20 21-Oct-2011
1298    ------------------------
1299    
1300    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1301        a POSIX class. After further experiments with Perl, which convinced me that
1302        Perl has bugs and confusions, a closing square bracket is no longer allowed
1303        in a POSIX name. This bug also affected patterns with classes that started
1304        with full stops.
1305    
1306    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1307        captured substring, but while checking the failing first alternative,
1308        substring 1 is temporarily captured. If the output vector supplied to
1309        pcre_exec() was not big enough for this capture, the yield of the function
1310        was still zero ("insufficient space for captured substrings"). This cannot
1311        be totally fixed without adding another stack variable, which seems a lot
1312        of expense for a edge case. However, I have improved the situation in cases
1313        such as /(a)(b)x|abc/ matched against "abc", where the return code
1314        indicates that fewer than the maximum number of slots in the ovector have
1315        been set.
1316    
1317    3.  Related to (2) above: when there are more back references in a pattern than
1318        slots in the output vector, pcre_exec() uses temporary memory during
1319        matching, and copies in the captures as far as possible afterwards. It was
1320        using the entire output vector, but this conflicts with the specification
1321        that only 2/3 is used for passing back captured substrings. Now it uses
1322        only the first 2/3, for compatibility. This is, of course, another edge
1323        case.
1324    
1325    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
1326        main code base, and can be used by building with --enable-jit. When this is
1327        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1328        runtime --no-jit option is given.
1329    
1330    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
1331        ovector, the return from the function was zero, implying that there were
1332        other matches that did not fit. The correct "exactly full" value is now
1333        returned.
1334    
1335    6.  If a subpattern that was called recursively or as a subroutine contained
1336        (*PRUNE) or any other control that caused it to give a non-standard return,
1337        invalid errors such as "Error -26 (nested recursion at the same subject
1338        position)" or even infinite loops could occur.
1339    
1340    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1341        computing the minimum length on reaching *ACCEPT, and so ended up with the
1342        wrong value of 1 rather than 0. Further investigation indicates that
1343        computing a minimum subject length in the presence of *ACCEPT is difficult
1344        (think back references, subroutine calls), and so I have changed the code
1345        so that no minimum is registered for a pattern that contains *ACCEPT.
1346    
1347    8.  If (*THEN) was present in the first (true) branch of a conditional group,
1348        it was not handled as intended. [But see 16 below.]
1349    
1350    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1351        Sheri Pierce.
1352    
1353    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1354        the first byte in a match must be "a".
1355    
1356    11. Change 17 for 8.13 increased the recursion depth for patterns like
1357        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1358        pattern contains any instances of (*THEN). If it does not, the old
1359        optimizations are restored. It would be nice to do this on a per-group
1360        basis, but at the moment that is not feasible.
1361    
1362    12. In some environments, the output of pcretest -C is CRLF terminated. This
1363        broke RunTest's code that checks for the link size. A single white space
1364        character after the value is now allowed for.
1365    
1366    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1367        For "fr", it uses the Windows-specific input and output files.
1368    
1369    14. If (*THEN) appeared in a group that was called recursively or as a
1370        subroutine, it did not work as intended. [But see next item.]
1371    
1372    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1373        pattern fragments (but not containing any | characters). If A and B are
1374        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1375        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1376        D. In other words, Perl considers parentheses that do not contain any |
1377        characters to be part of a surrounding alternative, whereas PCRE was
1378        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1379        differently. PCRE now behaves in the same way as Perl, except in the case
1380        of subroutine/recursion calls such as (?1) which have in any case always
1381        been different (but PCRE had them first :-).
1382    
1383    16. Related to 15 above: Perl does not treat the | in a conditional group as
1384        creating alternatives. Such a group is treated in the same way as an
1385        ordinary group without any | characters when processing (*THEN). PCRE has
1386        been changed to match Perl's behaviour.
1387    
1388    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1389        RunGrepTest script failed.
1390    
1391    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1392        inevitable for groups that contain captures, but it can lead to a lot of
1393        stack use in large patterns. The old behaviour has been restored for atomic
1394        groups that do not contain any capturing parentheses.
1395    
1396    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1397        suppress the check for a minimum subject length at run time. (If it was
1398        given to pcre_exec() or pcre_dfa_exec() it did work.)
1399    
1400    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1401        fail to work when decoding hex characters in data strings in EBCDIC
1402        environments.
1403    
1404    21. It appears that in at least one Mac OS environment, the isxdigit() function
1405        is implemented as a macro that evaluates to its argument more than once,
1406        contravening the C 90 Standard (I haven't checked a later standard). There
1407        was an instance in pcretest which caused it to go wrong when processing
1408        \x{...} escapes in subject strings. The has been rewritten to avoid using
1409        things like p++ in the argument of isxdigit().
1410    
1411    
1412    Version 8.13 16-Aug-2011
1413  ------------------------  ------------------------
1414    
1415  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 20  Version 8.13 30-Apr-2011 Line 1428  Version 8.13 30-Apr-2011
1428      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1429      2-byte code at the end of the subject (it thought there wasn't enough data      2-byte code at the end of the subject (it thought there wasn't enough data
1430      left).      left).
1431    
1432  5.  Comprehensive information about what went wrong is now returned by  5.  Comprehensive information about what went wrong is now returned by
1433      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1434      as the output vector has at least 2 elements. The offset of the start of      as the output vector has at least 2 elements. The offset of the start of
1435      the failing character and a reason code are placed in the vector.      the failing character and a reason code are placed in the vector.
1436    
1437  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
1438      now returned is for the first byte of the failing character, instead of the      now returned is for the first byte of the failing character, instead of the
1439      last byte inspected. This is an incompatible change, but I hope it is small      last byte inspected. This is an incompatible change, but I hope it is small
1440      enough not to be a problem. It makes the returned offset consistent with      enough not to be a problem. It makes the returned offset consistent with
1441      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
1442    
1443  7.  pcretest now gives a text phrase as well as the error number when  7.  pcretest now gives a text phrase as well as the error number when
1444      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1445      failure, the offset and reason code are output.      failure, the offset and reason code are output.
1446    
1447  8.  When \R was used with a maximizing quantifier it failed to skip backwards  8.  When \R was used with a maximizing quantifier it failed to skip backwards
1448      over a \r\n pair if the subsequent match failed. Instead, it just skipped      over a \r\n pair if the subsequent match failed. Instead, it just skipped
1449      back over a single character (\n). This seems wrong (because it treated the      back over a single character (\n). This seems wrong (because it treated the
1450      two characters as a single entity when going forwards), conflicts with the      two characters as a single entity when going forwards), conflicts with the
1451      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1452      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1453      has been changed.      has been changed.
1454    
1455    9.  Some internal refactoring has changed the processing so that the handling
1456        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1457        time (the PCRE_DOTALL option was changed this way some time ago: version
1458        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1459        which was always a bit of a fudge. It also means that there is one less
1460        argument for the match() function, which reduces its stack requirements
1461        slightly. This change also fixes an incompatibility with Perl: the pattern
1462        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1463    
1464    10. More internal refactoring has drastically reduced the number of recursive
1465        calls to match() for possessively repeated groups such as (abc)++ when
1466        using pcre_exec().
1467    
1468    11. While implementing 10, a number of bugs in the handling of groups were
1469        discovered and fixed:
1470    
1471        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1472        (a|)*(?1) gave a compile-time internal error.
1473        ((a|)+)+  did not notice that the outer group could match an empty string.
1474        (^a|^)+   was not marked as anchored.
1475        (.*a|.*)+ was not marked as matching at start or after a newline.
1476    
1477    12. Yet more internal refactoring has removed another argument from the match()
1478        function. Special calls to this function are now indicated by setting a
1479        value in a variable in the "match data" data block.
1480    
1481    13. Be more explicit in pcre_study() instead of relying on "default" for
1482        opcodes that mean there is no starting character; this means that when new
1483        ones are added and accidentally left out of pcre_study(), testing should
1484        pick them up.
1485    
1486    14. The -s option of pcretest has been documented for ages as being an old
1487        synonym of -m (show memory usage). I have changed it to mean "force study
1488        for every regex", that is, assume /S for every regex. This is similar to -i
1489        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1490        using it. It makes it easier to run collections of tests with and without
1491        study enabled, and thereby test pcre_study() more easily. All the standard
1492        tests are now run with and without -s (but some patterns can be marked as
1493        "never study" - see 20 below).
1494    
1495    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1496        restoration of the capturing data to the outer values was not happening
1497        correctly.
1498    
1499    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1500        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1501        pattern had matched an empty string, and so incorrectly returned a no
1502        match.
1503    
1504    17. There was optimizing code for the last branch of non-capturing parentheses,
1505        and also for the obeyed branch of a conditional subexpression, which used
1506        tail recursion to cut down on stack usage. Unfortunately, now that there is
1507        the possibility of (*THEN) occurring in these branches, tail recursion is
1508        no longer possible because the return has to be checked for (*THEN). These
1509        two optimizations have therefore been removed. [But see 8.20/11 above.]
1510    
1511    18. If a pattern containing \R was studied, it was assumed that \R always
1512        matched two bytes, thus causing the minimum subject length to be
1513        incorrectly computed because \R can also match just one byte.
1514    
1515    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1516        was incorrectly computed.
1517    
1518    20. If /S is present twice on a test pattern in pcretest input, it now
1519        *disables* studying, thereby overriding the use of -s on the command line
1520        (see 14 above). This is necessary for one or two tests to keep the output
1521        identical in both cases.
1522    
1523    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1524        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1525    
1526    22. When an atomic group that contained a capturing parenthesis was
1527        successfully matched, but the branch in which it appeared failed, the
1528        capturing was not being forgotten if a higher numbered group was later
1529        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1530        group 1 to "a", when in fact it should be unset. This applied to multi-
1531        branched capturing and non-capturing groups, repeated or not, and also to
1532        positive assertions (capturing in negative assertions does not happen
1533        in PCRE) and also to nested atomic groups.
1534    
1535    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1536        subject after a captured substring, to make it easier to tell which of a
1537        number of identical substrings has been captured.
1538    
1539    24. The way atomic groups are processed by pcre_exec() has been changed so that
1540        if they are repeated, backtracking one repetition now resets captured
1541        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1542        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1543        "aaa". Previously, it would have been "a". As part of this code
1544        refactoring, the way recursive calls are handled has also been changed.
1545    
1546    25. If an assertion condition captured any substrings, they were not passed
1547        back unless some other capturing happened later. For example, if
1548        (?(?=(a))a) was matched against "a", no capturing was returned.
1549    
1550    26. When studying a pattern that contained subroutine calls or assertions,
1551        the code for finding the minimum length of a possible match was handling
1552        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1553        group 1 called group 2 while simultaneously a separate group 2 called group
1554        1). A stack overflow occurred in this case. I have fixed this by limiting
1555        the recursion depth to 10.
1556    
1557    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1558        Fortmann. This supports explicit test numbers on the command line, and has
1559        argument validation and error reporting.
1560    
1561    28. An instance of \X with an unlimited repeat could fail if at any point the
1562        first character it looked at was a mark character.
1563    
1564    29. Some minor code refactoring concerning Unicode properties and scripts
1565        should reduce the stack requirement of match() slightly.
1566    
1567    30. Added the '=' option to pcretest to check the setting of unused capturing
1568        slots at the end of the pattern, which are documented as being -1, but are
1569        not included in the return count.
1570    
1571    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1572        compiled something random. Now it gives a compile-time error (as does
1573        Perl).
1574    
1575    32. A *MARK encountered during the processing of a positive assertion is now
1576        recorded and passed back (compatible with Perl).
1577    
1578    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1579        had alternative anchored branches, the search for a second match in a line
1580        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1581        matched the line "0102" twice. The same bug affected patterns that started
1582        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1583        twice.
1584    
1585    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1586        does, and because of capturing effects, quantifying parenthesized
1587        assertions may at times be useful. Quantifiers are now allowed for
1588        parenthesized assertions.
1589    
1590    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1591    
1592    36. \g was being checked for fancy things in a character class, when it should
1593        just be a literal "g".
1594    
1595    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1596        appearance of a nested POSIX class supersedes an apparent external class.
1597        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1598        unescaped square brackets may also appear as part of class names. For
1599        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1600        more like Perl. (But see 8.20/1 above.)
1601    
1602    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1603        was because it thought it was \N{name}, which is not supported).
1604    
1605    39. Add minix to OS list not supporting the -S option in pcretest.
1606    
1607    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1608        cannot analyze patterns in sufficient detail to catch mutual recursions
1609        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1610        subgroup is called recursively as a subpattern for a second time at the
1611        same position in the subject string. In previous releases this might have
1612        been caught by the recursion limit, or it might have run out of stack.
1613    
1614    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1615        happen only once. PCRE was, however incorrectly giving a compile time error
1616        "recursive call could loop indefinitely" because it cannot analyze the
1617        pattern in sufficient detail. The compile time test no longer happens when
1618        PCRE is compiling a conditional subpattern, but actual runaway loops are
1619        now caught at runtime (see 40 above).
1620    
1621    42. It seems that Perl allows any characters other than a closing parenthesis
1622        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1623        has been changed to be the same.
1624    
1625    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1626        as not to get warnings when autogen.sh is called. Also changed
1627        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1628    
1629    44. To help people who use pcregrep to scan files containing exceedingly long
1630        lines, the following changes have been made:
1631    
1632        (a) The default value of the buffer size parameter has been increased from
1633            8K to 20K. (The actual buffer used is three times this size.)
1634    
1635        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1636            PCRE is built.
1637    
1638        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1639            to be set at run time.
1640    
1641        (d) Numerical values in pcregrep options can be followed by K or M, for
1642            example --buffer-size=50K.
1643    
1644        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1645            given and the return code is set to 2.
1646    
1647    45. Add a pointer to the latest mark to the callout data block.
1648    
1649    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1650        partial match of an empty string instead of no match. This was specific to
1651        the use of ".".
1652    
1653    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1654        complete match instead of a partial match. This bug was dependent on both
1655        the PCRE_UTF8 and PCRE_DOTALL options being set.
1656    
1657    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1658        starting byte set, because \b was not being ignored.
1659    
1660    
1661  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
1662  ------------------------  ------------------------
# Line 695  Version 7.9 11-Apr-09 Line 2308  Version 7.9 11-Apr-09
2308  7.  A pattern that could match an empty string could cause pcregrep to loop; it  7.  A pattern that could match an empty string could cause pcregrep to loop; it
2309      doesn't make sense to accept an empty string match in pcregrep, so I have      doesn't make sense to accept an empty string match in pcregrep, so I have
2310      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2311      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2312        8.33.]
2313    
2314  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2315      start or after a newline", because the conditional assertion was not being      start or after a newline", because the conditional assertion was not being
# Line 938  Version 7.7 07-May-08 Line 2552  Version 7.7 07-May-08
2552      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2553      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2554      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2555      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2556      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2557      was subsequently set up correctly.)      was subsequently set up correctly.)
2558    

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