/[pcre]/code/trunk/ChangeLog

Diff of /code/trunk/ChangeLog

Parent Directory | Revision Log | View Patch Patch

-revision 588 by ph10,
Sat Jan 15 11:22:47 2011 UTC
+revision 1553 by ph10,
Tue Apr 28 11:36:24 2015 UTC
 Line 1
  ChangeLog for PCRE
  ------------------
- Version 8.15 12-Jan-2011
+ Version 8.37 28-April-2015
+ --------------------------
+.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
+     for those parentheses to be closed with whatever has been captured so far.
+     However, it was failing to mark any other groups between the hightest
+     capture so far and the currrent group as "unset". Thus, the ovector for
+     those groups contained whatever was previously there. An example is the
+     pattern /(x)|((*ACCEPT))/ when matched against "abcd".
+.  If an assertion condition was quantified with a minimum of zero (an odd
+     thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
+.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
+     unrecognized modifier, a crash could occur.
+.  An attempt to do global matching in pcretest with a zero-length ovector
+     caused a crash.
+.  Fixed a memory leak during matching that could occur for a subpattern
+     subroutine call (recursive or otherwise) if the number of captured groups
+     that had to be saved was greater than ten.
+.  Catch a bad opcode during auto-possessification after compiling a bad UTF
+     string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
+     UTF with NO_UTF_CHECK is documented as having an undefined outcome.
+.  A UTF pattern containing a "not" match of a non-ASCII character and a
+     subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
+. When a pattern is compiled, it remembers the highest back reference so that
+    when matching, if the ovector is too small, extra memory can be obtained to
+    use instead. A conditional subpattern whose condition is a check on a
+    capture having happened, such as, for example in the pattern
+    /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
+    setting the highest backreference number. This mattered only if pcre_exec()
+    was called with an ovector that was too small to hold the capture, and there
+    was no other kind of back reference (a situation which is probably quite
+    rare). The effect of the bug was that the condition was always treated as
+    FALSE when the capture could not be consulted, leading to a incorrect
+    behaviour by pcre_exec(). This bug has been fixed.
+. A reference to a duplicated named group (either a back reference or a test
+    for being set in a conditional) that occurred in a part of the pattern where
+    PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
+    to be incorrectly calculated, leading to overwriting.
+. A mutually recursive set of back references such as (\2)(\1) caused a
+     segfault at study time (while trying to find the minimum matching length).
+     The infinite loop is now broken (with the minimum length unset, that is,
+     zero).
+. If an assertion that was used as a condition was quantified with a minimum
+     of zero, matching went wrong. In particular, if the whole group had
+     unlimited repetition and could match an empty string, a segfault was
+     likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
+     assertions to be quantified, but not if they are being used as conditions,
+     so the above pattern is faulted by Perl. PCRE has now been changed so that
+     it also rejects such patterns.
+. A possessive capturing group such as (a)*+ with a minimum repeat of zero
+     failed to allow the zero-repeat case if pcre2_exec() was called with an
+     ovector too small to capture the group.
+. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
+     Red Hat Product Security:
+     (a) A crash if /K and /F were both set with the option to save the compiled
+     pattern.
+     (b) Another crash if the option to print captured substrings in a callout
+     was combined with setting a null ovector, for example \O\C+ as a subject
+     string.
+. A pattern such as "((?2){0,1999}())?", which has a group containing a
+     forward reference repeated a large (but limited) number of times within a
+     repeated outer group that has a zero minimum quantifier, caused incorrect
+     code to be compiled, leading to the error "internal error:
+     previously-checked referenced subpattern not found" when an incorrect
+     memory address was read. This bug was reported as "heap overflow",
+     discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
+     CVE-2015-2325.
+. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
+     call within a group that also contained a recursive back reference caused
+     incorrect code to be compiled. This bug was reported as "heap overflow",
+     discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
+     number CVE-2015-2326.
+. Computing the size of the JIT read-only data in advance has been a source
+     of various issues, and new ones are still appear unfortunately. To fix
+     existing and future issues, size computation is eliminated from the code,
+     and replaced by on-demand memory allocation.
+. A pattern such as /(?i)[A-`]/, where characters in the other case are
+     adjacent to the end of the range, and the range contained characters with
+     more than one other case, caused incorrect behaviour when compiled in UTF
+     mode. In that example, the range a-j was left out of the class.
+. Fix JIT compilation of conditional blocks, which assertion
+     is converted to (*FAIL). E.g: /(?(?!))/.
+. The pattern /(?(?!)^)/ caused references to random memory. This bug was
+     discovered by the LLVM fuzzer.
+. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
+     when this assertion was used as a condition, for example (?(?!)a|b). In
+     pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
+     error about an unsupported item.
+. For some types of pattern, for example /Z*(|d*){216}/, the auto-
+     possessification code could take exponential time to complete. A recursion
+     depth limit of 1000 has been imposed to limit the resources used by this
+     optimization.
+. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
+     such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
+     because \S ensures they are all in the class. The code for doing this was
+     interacting badly with the code for computing the amount of space needed to
+     compile the pattern, leading to a buffer overflow. This bug was discovered
+     by the LLVM fuzzer.
+. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
+     other kinds of group caused stack overflow at compile time. This bug was
+     discovered by the LLVM fuzzer.
+. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
+     between a subroutine call and its quantifier was incorrectly compiled,
+     leading to buffer overflow or other errors. This bug was discovered by the
+     LLVM fuzzer.
+. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
+     assertion after (?(. The code was failing to check the character after
+     (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
+     was discovered by the LLVM fuzzer.
+. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
+     a fixed maximum following a group that contains a subroutine reference was
+     incorrectly compiled and could trigger buffer overflow. This bug was
+     discovered by the LLVM fuzzer.
+. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
+     caused a stack overflow instead of the diagnosis of a non-fixed length
+     lookbehind assertion. This bug was discovered by the LLVM fuzzer.
+. The use of \K in a positive lookbehind assertion in a non-anchored pattern
+     (e.g. /(?<=\Ka)/) could make pcregrep loop.
+. There was a similar problem to 36 in pcretest for global matches.
+. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
+     and a subsequent item in the pattern caused a non-match, backtracking over
+     the repeated \X did not stop, but carried on past the start of the subject,
+     causing reference to random memory and/or a segfault. There were also some
+     other cases where backtracking after \C could crash. This set of bugs was
+     discovered by the LLVM fuzzer.
+. The function for finding the minimum length of a matching string could take
+     a very long time if mutual recursion was present many times in a pattern,
+     for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
+     method has been implemented. This infelicity was discovered by the LLVM
+     fuzzer.
+. Static linking against the PCRE library using the pkg-config module was
+     failing on missing pthread symbols.
+ Version 8.36 26-September-2014
+ ------------------------------
+.  Got rid of some compiler warnings in the C++ modules that were shown up by
+     -Wmissing-field-initializers and -Wunused-parameter.
+.  The tests for quantifiers being too big (greater than 65535) were being
+     applied after reading the number, and stupidly assuming that integer
+     overflow would give a negative number. The tests are now applied as the
+     numbers are read.
+.  Tidy code in pcre_exec.c where two branches that used to be different are
+     now the same.
+.  The JIT compiler did not generate match limit checks for certain
+     bracketed expressions with quantifiers. This may lead to exponential
+     backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
+     issue should be resolved now.
+.  Fixed an issue, which occures when nested alternatives are optimized
+     with table jumps.
+.  Inserted two casts and changed some ints to size_t in the light of some
+     reported 64-bit compiler warnings (Bugzilla 1477).
+.  Fixed a bug concerned with zero-minimum possessive groups that could match
+     an empty string, which sometimes were behaving incorrectly in the
+     interpreter (though correctly in the JIT matcher). This pcretest input is
+     an example:
+       '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
+       NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
+     the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
+     JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
+     for an empty string was breaking the inner loop and carrying on at a lower
+     level, when possessive repeated groups should always return to a higher
+     level as they have no backtrack points in them. The empty string test now
+     occurs at the outer level.
+.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
+     ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
+.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
+     doesn't).
+. Change 8.34/15 introduced a bug that caused the amount of memory needed
+     to hold a pattern to be incorrectly computed (too small) when there were
+     named back references to duplicated names. This could cause "internal
+     error: code overflow" or "double free or corruption" or other memory
+     handling errors.
+. When named subpatterns had the same prefixes, back references could be
+     confused. For example, in this pattern:
+       /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
+     the reference to 'Name' was incorrectly treated as a reference to a
+     duplicate name.
+. A pattern such as /^s?c/mi8 where the optional character has more than
+     one "other case" was incorrectly compiled such that it would only try to
+     match starting at "c".
+. When a pattern starting with \s was studied, VT was not included in the
+     list of possible starting characters; this should have been part of the
+.34/18 patch.
+. If a character class started [\Qx]... where x is any character, the class
+     was incorrectly terminated at the ].
+. If a pattern that started with a caseless match for a character with more
+     than one "other case" was studied, PCRE did not set up the starting code
+     unit bit map for the list of possible characters. Now it does. This is an
+     optimization improvement, not a bug fix.
+. The Unicode data tables have been updated to Unicode 7.0.0.
+. Fixed a number of memory leaks in pcregrep.
+. Avoid a compiler warning (from some compilers) for a function call with
+     a cast that removes "const" from an lvalue by using an intermediate
+     variable (to which the compiler does not object).
+. Incorrect code was compiled if a group that contained an internal recursive
+     back reference was optional (had quantifier with a minimum of zero). This
+     example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
+     caused segmentation faults because of stack overflows at compile time.
+. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
+     group that is quantified with an indefinite repeat, caused a compile-time
+     loop which used up all the system stack and provoked a segmentation fault.
+     This was not the same bug as 19 above.
+. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
+     Patch by Mike Frysinger.
+ Version 8.35 04-April-2014
+ --------------------------
+.  A new flag is set, when property checks are present in an XCLASS.
+     When this flag is not set, PCRE can perform certain optimizations
+     such as studying these XCLASS-es.
+.  The auto-possessification of character sets were improved: a normal
+     and an extended character set can be compared now. Furthermore
+     the JIT compiler optimizes more character set checks.
+.  Got rid of some compiler warnings for potentially uninitialized variables
+     that show up only when compiled with -O2.
+.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
+     of a match later then the end of the match. The pcretest program was not
+     handling the case sensibly - it was outputting from the start to the next
+     binary zero. It now reports this situation in a message, and outputs the
+     text from the end to the start.
+.  Fast forward search is improved in JIT. Instead of the first three
+     characters, any three characters with fixed position can be searched.
+     Search order: first, last, middle.
+.  Improve character range checks in JIT. Characters are read by an inprecise
+     function now, which returns with an unknown value if the character code is
+     above a certain threshold (e.g: 256). The only limitation is that the value
+     must be bigger than the threshold as well. This function is useful when
+     the characters above the threshold are handled in the same way.
+.  The macros whose names start with RAWUCHAR are placeholders for a future
+     mode in which only the bottom 21 bits of 32-bit data items are used. To
+     make this more memorable for those maintaining the code, the names have
+     been changed to start with UCHAR21, and an extensive comment has been added
+     to their definition.
+.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
+     to the export list in Makefile.am (they were accidentally omitted from the
+.34 tarball).
+.  The informational output from pcretest used the phrase "starting byte set"
+     which is inappropriate for the 16-bit and 32-bit libraries. As the output
+     for "first char" and "need char" really means "non-UTF-char", I've changed
+     "byte" to "char", and slightly reworded the output. The documentation about
+     these values has also been (I hope) clarified.
+. Another JIT related optimization: use table jumps for selecting the correct
+     backtracking path, when more than four alternatives are present inside a
+     bracket.
+. Empty match is not possible, when the minimum length is greater than zero,
+     and there is no \K in the pattern. JIT should avoid empty match checks in
+     such cases.
+. In a caseless character class with UCP support, when a character with more
+     than one alternative case was not the first character of a range, not all
+     the alternative cases were added to the class. For example, s and \x{17f}
+     are both alternative cases for S: the class [RST] was handled correctly,
+     but [R-T] was not.
+. The configure.ac file always checked for pthread support when JIT was
+     enabled. This is not used in Windows, so I have put this test inside a
+     check for the presence of windows.h (which was already tested for).
+. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
+     The algorithm provides a way to skip certain starting offsets, and usually
+     faster than linear prefix searches.
+. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
+     as for 'fr_FR' and 'french'. For some reason, however, it then used the
+     Windows-specific input and output files, which have 'french' screwed in.
+     So this could never have worked. One of the problems with locales is that
+     they aren't always the same. I have now updated RunTest so that it checks
+     the output of the locale test (test 3) against three different output
+     files, and it allows the test to pass if any one of them matches. With luck
+     this should make the test pass on some versions of Solaris where it was
+     failing. Because of the uncertainty, the script did not used to stop if
+     test 3 failed; it now does. If further versions of a French locale ever
+     come to light, they can now easily be added.
+. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
+     there was a message during ./configure, but it did not stop. This now
+     provokes an error. The invalid example in README has been corrected.
+     If a value less than the minimum is given, the minimum value has always
+     been used, but now a warning is given.
+. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
+     was a bug in the test system, which is now fixed. Also, the list of various
+     configurations that are tested for each release did not have one with both
+/32 bits and --enable-bar-anycrlf. It now does.
+. pcretest was missing "-C bsr" for displaying the \R default setting.
+. Little endian PowerPC systems are supported now by the JIT compiler.
+. The fast forward newline mechanism could enter to an infinite loop on
+     certain invalid UTF-8 input. Although we don't support these cases
+     this issue can be fixed by a performance optimization.
+. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
+     not take account if existing stack usage. There is now a new global
+     variable called pcre_stack_guard that can be set to point to an external
+     function to check stack availability. It is called at the start of
+     processing every parenthesized group.
+. A typo in the code meant that in ungreedy mode the max/min qualifier
+     behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
+     not match "ab".
+. When UTF was disabled, the JIT program reported some incorrect compile
+     errors. These messages are silenced now.
+. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
+     compiler.
+. Change all the temporary files used in RunGrepTest to be different to those
+     used by RunTest so that the tests can be run simultaneously, for example by
+     "make -j check".
+ Version 8.34 15-December-2013
+ -----------------------------
+.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
+     executable memory. Patch inspired by Carsten Klein.
+.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
+     this macro is never tested and has no effect, because the work to support
+     coverage involves only compiling and linking options and special targets in
+     the Makefile. The comment in config.h implied that defining the macro would
+     enable coverage support, which is totally false. There was also support for
+     setting this macro in the CMake files (my fault, I just copied it from
+     configure). SUPPORT_GCOV has now been removed.
+.  Make a small performance improvement in strlen16() and strlen32() in
+     pcretest.
+.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
+     detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
+     these cases). There was also one in pcretest.c.
+.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
+.  In UTF mode, the code for checking whether a group could match an empty
+     string (which is used for indefinitely repeated groups to allow for
+     breaking an infinite loop) was broken when the group contained a repeated
+     negated single-character class with a character that occupied more than one
+     data item and had a minimum repetition of zero (for example, [^\x{100}]* in
+     UTF-8 mode). The effect was undefined: the group might or might not be
+     deemed as matching an empty string, or the program might have crashed.
+.  The code for checking whether a group could match an empty string was not
+     recognizing that \h, \H, \v, \V, and \R must match a character.
+.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
+     an empty string. If it can, pcretest shows this in its information output.
+.  Fixed two related bugs that applied to Unicode extended grapheme clusters
+     that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
+     matched by pcre_exec() without using JIT:
+     (a) If the rest of the pattern did not match after a maximal run of
+         grapheme clusters, the code for backing up to try with fewer of them
+         did not always back up over a full grapheme when characters that do not
+         have the modifier quality were involved, e.g. Hangul syllables.
+     (b) If the match point in a subject started with modifier character, and
+         there was no match, the code could incorrectly back up beyond the match
+         point, and potentially beyond the first character in the subject,
+         leading to a segfault or an incorrect match result.
+. A conditional group with an assertion condition could lead to PCRE
+     recording an incorrect first data item for a match if no other first data
+     item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
+     first data item, and therefore matched "ca" after "c" instead of at the
+     start.
+. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
+     bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
+. The source of pcregrep now includes z/OS-specific code so that it can be
+     compiled for z/OS as part of the special z/OS distribution.
+. Added the -T and -TM options to pcretest.
+. The code in pcre_compile.c for creating the table of named capturing groups
+     has been refactored. Instead of creating the table dynamically during the
+     actual compiling pass, the information is remembered during the pre-compile
+     pass (on the stack unless there are more than 20 named groups, in which
+     case malloc() is used) and the whole table is created before the actual
+     compile happens. This has simplified the code (it is now nearly 150 lines
+     shorter) and prepared the way for better handling of references to groups
+     with duplicate names.
+. A back reference to a named subpattern when there is more than one of the
+     same name now checks them in the order in which they appear in the pattern.
+     The first one that is set is used for the reference. Previously only the
+     first one was inspected. This change makes PCRE more compatible with Perl.
+. Unicode character properties were updated from Unicode 6.3.0.
+. The compile-time code for auto-possessification has been refactored, based
+     on a patch by Zoltan Herczeg. It now happens after instead of during
+     compilation. The code is cleaner, and more cases are handled. The option
+     PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
+     options in pcretest are provided to set it. It can also be set by
+     (*NO_AUTO_POSSESS) at the start of a pattern.
+. The character VT has been added to the default ("C" locale) set of
+     characters that match \s and are generally treated as white space,
+     following this same change in Perl 5.18. There is now no difference between
+     "Perl space" and "POSIX space". Whether VT is treated as white space in
+     other locales depends on the locale.
+. The code for checking named groups as conditions, either for being set or
+     for being recursed, has been refactored (this is related to 14 and 15
+     above). Processing unduplicated named groups should now be as fast at
+     numerical groups, and processing duplicated groups should be faster than
+     before.
+. Two patches to the CMake build system, by Alexander Barkov:
+       (1) Replace the "source" command by "." in CMakeLists.txt because
+           "source" is a bash-ism.
+       (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
+           without these the CMake build does not work on Solaris.
+. Perl has changed its handling of \8 and \9. If there is no previously
+     encountered capturing group of those numbers, they are treated as the
+     literal characters 8 and 9 instead of a binary zero followed by the
+     literals. PCRE now does the same.
+. Following Perl, added \o{} to specify codepoints in octal, making it
+     possible to specify values greater than 0777 and also making them
+     unambiguous.
+. Perl now gives an error for missing closing braces after \x{... instead of
+     treating the string as literal. PCRE now does the same.
+. RunTest used to grumble if an inappropriate test was selected explicitly,
+     but just skip it when running all tests. This make it awkward to run ranges
+     of tests when one of them was inappropriate. Now it just skips any
+     inappropriate tests, as it always did when running all tests.
+. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
+     character types such as \d or \w, too many callouts were inserted, and the
+     data that they returned was rubbish.
+. In UCP mode, \s was not matching two of the characters that Perl matches,
+     namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
+     were matched by \h. The code has now been refactored so that the lists of
+     the horizontal and vertical whitespace characters used for \h and \v (which
+     are defined only in one place) are now also used for \s.
+. Add JIT support for the 64 bit TileGX architecture.
+     Patch by Jiong Wang (Tilera Corporation).
+. Possessive quantifiers for classes (both explicit and automatically
+     generated) now use special opcodes instead of wrapping in ONCE brackets.
+. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
+     (because it's meaningless), this was not happening when PCRE_CASELESS was
+     set. Not wrong, but inefficient.
+. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
+     properties for \w, \d, etc) is present in a test regex. Otherwise if the
+     test contains no characters greater than 255, Perl doesn't realise it
+     should be using Unicode semantics.
+. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
+     [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
+     does in Unicode mode.
+. Added the "forbid" facility to pcretest so that putting tests into the
+     wrong test files can sometimes be quickly detected.
+. There is now a limit (default 250) on the depth of nesting of parentheses.
+     This limit is imposed to control the amount of system stack used at compile
+     time. It can be changed at build time by --with-parens-nest-limit=xxx or
+     the equivalent in CMake.
+. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
+     errors. Perl warns for these when in warning mode, but PCRE has no facility
+     for giving warnings.
+. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
+     However, this was not working for (?!) because it is optimized to (*FAIL),
+     for which PCRE does not allow quantifiers. The optimization is now disabled
+     when a quantifier follows (?!). I can't see any use for this, but it makes
+     things uniform.
+. Perl no longer allows group names to start with digits, so I have made this
+     change also in PCRE. It simplifies the code a bit.
+. In extended mode, Perl ignores spaces before a + that indicates a
+     possessive quantifier. PCRE allowed a space before the quantifier, but not
+     before the possessive +. It now does.
+. The use of \K (reset reported match start) within a repeated possessive
+     group such as (a\Kb)*+ was not working.
+. Document that the same character tables must be used at compile time and
+     run time, and that the facility to pass tables to pcre_exec() and
+     pcre_dfa_exec() is for use only with saved/restored patterns.
+. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
+     features for Builds with MSVC:
+. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
+        builds). The .rc files can be used to set FileDescription and many other
+        attributes.
+. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
+        This allows higher-level build scripts which want .pdb files to avoid
+        hard-coding the exact files needed."
+. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
+     mean "start of word" and "end of word", respectively, as a transition aid.
+. A minimizing repeat of a class containing codepoints greater than 255 in
+     non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
+     compiled to use the heap for recursion.
+. Got rid of some compiler warnings for unused variables when UTF but not UCP
+     is configured.
+ Version 8.33 28-May-2013
+ ------------------------
+.  Added 'U' to some constants that are compared to unsigned integers, to
+     avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
+     variables that are added to signed variables, to ensure the result is
+     signed and can be negated.
+.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
+     CMake config files.
+.  Revise the creation of config.h.generic so that all boolean macros are
+     #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
+     overriding via -D on the command line possible.
+.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
+     to unsigned int is reported to make a quite noticeable speed difference in
+     a specific Windows environment. Testing on Linux did also appear to show
+     some benefit (and it is clearly not harmful). Also fixed the definition of
+     Xop which should be unsigned.
+.  Related to (4), changing the definition of the intermediate variable cc
+     in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
+     improvements.
+.  Fix forward search in JIT when link size is 3 or greater. Also removed some
+     unnecessary spaces.
+.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
+     and later.
+.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
+.  Optimizing fast_forward_start_bits in JIT.
+. Adding support for callouts in JIT, and fixing some issues revealed
+     during this work. Namely:
+     (a) Unoptimized capturing brackets incorrectly reset on backtrack.
+     (b) Minimum length was not checked before the matching is started.
+. The value of capture_last that is passed to callouts was incorrect in some
+     cases when there was a capture on one path that was subsequently abandoned
+     after a backtrack. Also, the capture_last value is now reset after a
+     recursion, since all captures are also reset in this case.
+. The interpreter no longer returns the "too many substrings" error in the
+     case when an overflowing capture is in a branch that is subsequently
+     abandoned after a backtrack.
+. In the pathological case when an offset vector of size 2 is used, pcretest
+     now prints out the matched string after a yield of 0 or 1.
+. Inlining subpatterns in recursions, when certain conditions are fulfilled.
+     Only supported by the JIT compiler at the moment.
+. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
+. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
+     offset of the starting point of the matching process, provided the offsets
+     vector is large enough.
+. The \A escape now records a lookbehind value of 1, though its execution
+     does not actually inspect the previous character. This is to ensure that,
+     in partial multi-segment matching, at least one character from the old
+     segment is retained when a new segment is processed. Otherwise, if there
+     are no lookbehinds in the pattern, \A might match incorrectly at the start
+     of a new segment.
+. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
+. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
+     gives some modest performance improvement in 8-bit mode.
+. Added the PCRE-specific property \p{Xuc} for matching characters that can
+     be expressed in certain programming languages using Universal Character
+     Names.
+. Unicode validation has been updated in the light of Unicode Corrigendum #9,
+     which points out that "non characters" are not "characters that may not
+     appear in Unicode strings" but rather "characters that are reserved for
+     internal use and have only local meaning".
+. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
+     there was a conditional group that depended on an assertion, if the
+     assertion was false, the callout that immediately followed the alternation
+     in the condition was skipped when pcre_exec() was used for matching.
+. Allow an explicit callout to be inserted before an assertion that is the
+     condition for a conditional group, for compatibility with automatic
+     callouts, which always insert a callout at this point.
+. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
+     confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
+. (*PRUNE) is now supported by the JIT compiler.
+. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
+. Fix the case where there are two or more SKIPs with arguments that may be
+     ignored.
+. (*SKIP) is now supported by the JIT compiler.
+. (*THEN) is now supported by the JIT compiler.
+. Update RunTest with additional test selector options.
+. The way PCRE handles backtracking verbs has been changed in two ways.
+     (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
+     SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
+     backtracking. In some cases this makes it more Perl-compatible, but Perl's
+     rather obscure rules do not always do the same thing.
+     (2) Previously, backtracking verbs were confined within assertions. This is
+     no longer the case for positive assertions, except for (*ACCEPT). Again,
+     this sometimes improves Perl compatibility, and sometimes does not.
+. A number of tests that were in test 2 because Perl did things differently
+     have been moved to test 1, because either Perl or PCRE has changed, and
+     these tests are now compatible.
+. Backtracking control verbs are now handled in the same way in JIT and
+     interpreter.
+. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
+     contained a forward subroutine reference caused a compile error.
+. Auto-detect and optimize limited repetitions in JIT.
+. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
+     blocking (*UTF) etc.
+. In the interpreter, maximizing pattern repetitions for characters and
+     character types now use tail recursion, which reduces stack usage.
+. The value of the max lookbehind was not correctly preserved if a compiled
+     and saved regex was reloaded on a host of different endianness.
+. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
+     of the compiled pattern block, expand the flags field from 16 to 32 bits
+     because it was almost full.
+. Try madvise first before posix_madvise.
+. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
+     with a pattern such as ^$. It has taken 4 years for anybody to notice! The
+     original change locked out all matches of empty strings. This has been
+     changed so that one match of an empty string per line is recognized.
+     Subsequent searches on the same line (for colouring or for --only-matching,
+     for example) do not recognize empty strings.
+. Applied a user patch to fix a number of spelling mistakes in comments.
+. Data lines longer than 65536 caused pcretest to crash.
+. Clarified the data type for length and startoffset arguments for pcre_exec
+     and pcre_dfa_exec in the function-specific man pages, where they were
+     explicitly stated to be in bytes, never having been updated. I also added
+     some clarification to the pcreapi man page.
+. A call to pcre_dfa_exec() with an output vector size less than 2 caused
+     a segmentation fault.
+ Version 8.32 30-November-2012
+ -----------------------------
+.  Improved JIT compiler optimizations for first character search and single
+     character iterators.
+.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
+     Patch by Daniel Richard G.
+.  Single character iterator optimizations in the JIT compiler.
+.  Improved JIT compiler optimizations for character ranges.
+.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
+     Reported by Giuseppe D'Angelo.
+.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
+     of a line, was being set incorrectly in cases where .* appeared inside
+     atomic brackets at the start of a pattern, or where there was a subsequent
+     *PRUNE or *SKIP.
+.  Improved instruction cache flush for POWER/PowerPC.
+     Patch by Daniel Richard G.
+.  Fixed a number of issues in pcregrep, making it more compatible with GNU
+     grep:
+     (a) There is now no limit to the number of patterns to be matched.
+     (b) An error is given if a pattern is too long.
+     (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
+         are now supported.
+     (d) --exclude-from and --include-from (multiple use) have been added.
+     (e) Exclusions and inclusions now apply to all files and directories, not
+         just to those obtained from scanning a directory recursively.
+     (f) Multiple uses of -f and --file-list are now supported.
+     (g) In a Windows environment, the default for -d has been changed from
+         "read" (the GNU grep default) to "skip", because otherwise the presence
+         of a directory in the file list provokes an error.
+     (h) The documentation has been revised and clarified in places.
+.  Improve the matching speed of capturing brackets.
+. Changed the meaning of \X so that it now matches a Unicode extended
+     grapheme cluster.
+. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
+     out POSIX threads when JIT support is configured.
+. Added support for PCRE_STUDY_EXTRA_NEEDED.
+. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
+     structure could go wrong in environments where size_t is not the same size
+     as int.
+. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
+     set.
+. The EBCDIC support had decayed; later updates to the code had included
+     explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
+     general tidy up of EBCDIC-related issues, and the documentation was also
+     not quite right. There is now a test that can be run on ASCII systems to
+     check some of the EBCDIC-related things (but is it not a full test).
+. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
+     in a small tidy to the code.
+. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
+. If the --only-matching (-o) option in pcregrep is specified multiple
+     times, each one causes appropriate output. For example, -o1 -o2 outputs the
+     substrings matched by the 1st and 2nd capturing parentheses. A separating
+     string can be specified by --om-separator (default empty).
+. Improving the first n character searches.
+. Turn case lists for horizontal and vertical white space into macros so that
+     they are defined only once.
+. This set of changes together give more compatible Unicode case-folding
+     behaviour for characters that have more than one other case when UCP
+     support is available.
+     (a) The Unicode property table now has offsets into a new table of sets of
+         three or more characters that are case-equivalent. The MultiStage2.py
+         script that generates these tables (the pcre_ucd.c file) now scans
+         CaseFolding.txt instead of UnicodeData.txt for character case
+         information.
+     (b) The code for adding characters or ranges of characters to a character
+         class has been abstracted into a generalized function that also handles
+         case-independence. In UTF-mode with UCP support, this uses the new data
+         to handle characters with more than one other case.
+     (c) A bug that is fixed as a result of (b) is that codepoints less than 256
+         whose other case is greater than 256 are now correctly matched
+         caselessly. Previously, the high codepoint matched the low one, but not
+         vice versa.
+     (d) The processing of \h, \H, \v, and \ in character classes now makes use
+         of the new class addition function, using character lists defined as
+         macros alongside the case definitions of 20 above.
+     (e) Caseless back references now work with characters that have more than
+         one other case.
+     (f) General caseless matching of characters with more than one other case
+         is supported.
+. Unicode character properties were updated from Unicode 6.2.0
+. Improved CMake support under Windows. Patch by Daniel Richard G.
+. Add support for 32-bit character strings, and UTF-32
+. Major JIT compiler update (code refactoring and bugfixing).
+     Experimental Sparc 32 support is added.
+. Applied a modified version of Daniel Richard G's patch to create
+     pcre.h.generic and config.h.generic by "make" instead of in the
+     PrepareRelease script.
+. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
+     pcre_compile.c when checking for a zero character.
+. Introducing a native interface for JIT. Through this interface, the compiled
+     machine code can be directly executed. The purpose of this interface is to
+     provide fast pattern matching, so several sanity checks are not performed.
+     However, feature tests are still performed. The new interface provides
+.4x speedup compared to the old one.
+. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
+     the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
+     was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
+. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
+     greater than 0x7fffffff (which cannot be represented in UTF-8, even under
+     the "old" RFC 2279). Instead, it ended up passing a negative length to
+     pcre_exec().
+. Add support for GCC's visibility feature to hide internal functions.
+. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
+     "unknown -C option" after outputting 0 or 1.
+. There is now support for generating a code coverage report for the test
+     suite in environments where gcc is the compiler and lcov is installed. This
+     is mainly for the benefit of the developers.
+. If PCRE is built with --enable-valgrind, certain memory regions are marked
+     unaddressable using valgrind annotations, allowing valgrind to detect
+     invalid memory accesses. This is mainly for the benefit of the developers.
+. (*UTF) can now be used to start a pattern in any of the three libraries.
+. Give configure error if --enable-cpp but no C++ compiler found.
+ Version 8.31 06-July-2012
+ -------------------------
+.  Fixing a wrong JIT test case and some compiler warnings.
+.  Removed a bashism from the RunTest script.
+.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
+     to unsigned type, result still unsigned" that was given by an MS compiler
+     on encountering the code "-sizeof(xxx)".
+.  Partial matching support is added to the JIT compiler.
+.  Fixed several bugs concerned with partial matching of items that consist
+     of more than one character:
+     (a) /^(..)\1/ did not partially match "aba" because checking references was
+         done on an "all or nothing" basis. This also applied to repeated
+         references.
+     (b) \R did not give a hard partial match if \r was found at the end of the
+         subject.
+     (c) \X did not give a hard partial match after matching one or more
+         characters at the end of the subject.
+     (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
+         a partial match for the string "\r".
+     (e) When newline was set to CRLF, the metacharacter "." did not recognize
+         a partial match for a CR character at the end of the subject string.
+.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
+     running pcretest, the text "(JIT)" added to the output whenever JIT is
+     actually used to run the match.
+.  Individual JIT compile options can be set in pcretest by following -s+[+]
+     or /S+[+] with a digit between 1 and 7.
+.  OP_NOT now supports any UTF character not just single-byte ones.
+.  (*MARK) control verb is now supported by the JIT compiler.
+. The command "./RunTest list" lists the available tests without actually
+     running any of them. (Because I keep forgetting what they all are.)
+. Add PCRE_INFO_MAXLOOKBEHIND.
+. Applied a (slightly modified) user-supplied patch that improves performance
+     when the heap is used for recursion (compiled with --disable-stack-for-
+     recursion). Instead of malloc and free for each heap frame each time a
+     logical recursion happens, frames are retained on a chain and re-used where
+     possible. This sometimes gives as much as 30% improvement.
+. As documented, (*COMMIT) is now confined to within a recursive subpattern
+     call.
+. As documented, (*COMMIT) is now confined to within a positive assertion.
+. It is now possible to link pcretest with libedit as an alternative to
+     libreadline.
+. (*COMMIT) control verb is now supported by the JIT compiler.
+. The Unicode data tables have been updated to Unicode 6.1.0.
+. Added --file-list option to pcregrep.
+. Added binary file support to pcregrep, including the -a, --binary-files,
+     -I, and --text options.
+. The madvise function is renamed for posix_madvise for QNX compatibility
+     reasons. Fixed by Giuseppe D'Angelo.
+. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
+. Changed the option for creating symbolic links for 16-bit man pages from
+     -s to -sf so that re-installing does not cause issues.
+. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
+. Fixed a very old bug in pcretest that caused errors with restarted DFA
+     matches in certain environments (the workspace was not being correctly
+     retained). Also added to pcre_dfa_exec() a simple plausibility check on
+     some of the workspace data at the beginning of a restart.
+. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
+     was not doing so when it should - probably a typo introduced by SVN 528
+     (change 8.10/14).
+. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
+     \w+ when the character tables indicated that \x{c4} was a word character.
+     There were several related cases, all because the tests for doing a table
+     lookup were testing for characters less than 127 instead of 255.
+. If a pattern contains capturing parentheses that are not used in a match,
+     their slots in the ovector are set to -1. For those that are higher than
+     any matched groups, this happens at the end of processing. In the case when
+     there were back references that the ovector was too small to contain
+     (causing temporary malloc'd memory to be used during matching), and the
+     highest capturing number was not used, memory off the end of the ovector
+     was incorrectly being set to -1. (It was using the size of the temporary
+     memory instead of the true size.)
+. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
+     ovector size, it uses memory at the end of the block that it has got.
+. Check for an overlong MARK name and give an error at compile time. The
+     limit is 255 for the 8-bit library and 65535 for the 16-bit library.
+. JIT compiler update.
+. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
+     Rill for the patch.
+. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
+. Variable renamings in the PCRE-JIT compiler. No functionality change.
+. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
+     SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
+     was enabled.
+. Improve JIT code generation for greedy plus quantifier.
+. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
+to "aa" instead of to an empty string. The bug affected repeated groups
+     that could potentially match an empty string.
+. Optimizing single character iterators in JIT.
+. Wide characters specified with \uxxxx in JavaScript mode are now subject to
+     the same checks as \x{...} characters in non-JavaScript mode. Specifically,
+     codepoints that are too big for the mode are faulted, and in a UTF mode,
+     disallowed codepoints are also faulted.
+. If PCRE was compiled with UTF support, in three places in the DFA
+     matcher there was code that should only have been obeyed in UTF mode, but
+     was being obeyed unconditionally. In 8-bit mode this could cause incorrect
+     processing when bytes with values greater than 127 were present. In 16-bit
+     mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
+     both cases the values are those that cannot be the first data item in a UTF
+     character. The three items that might have provoked this were recursions,
+     possessively repeated groups, and atomic groups.
+. Ensure that libpcre is explicitly listed in the link commands for pcretest
+     and pcregrep, because some OS require shared objects to be explicitly
+     passed to ld, causing the link step to fail if they are not.
+. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
+     mode, patterns that started with \h* or \R* might be incorrectly matched.
+ Version 8.30 04-February-2012
+ -----------------------------
+.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
+     name is defined in ctype.h.
+.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
+     only in quite long subpatterns.
+.  Removed the function pcre_info(), which has been obsolete and deprecated
+     since it was replaced by pcre_fullinfo() in February 2000.
+.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
+     match a (*MARK), and the match failed at the start of the subject, a
+     reference to memory before the start of the subject could occur. This bug
+     was introduced by fix 17 of release 8.21.
+.  A reference to an unset group with zero minimum repetition was giving
+     totally wrong answers (in non-JavaScript-compatibility mode). For example,
+     /(another)?(\1?)test/ matched against "hello world test". This bug was
+     introduced in release 8.13.
+.  Add support for 16-bit character strings (a large amount of work involving
+     many changes and refactorings).
+.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
+     command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
+     from a file.
+.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
+     rounding is not applied in this particular case).
+.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
+     if they appear, or are escaped, in patterns.
+. Get rid of a number of -Wunused-but-set-variable warnings.
+. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
+     "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
+     Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
+     also returns the mark "x". This bug applied to capturing parentheses,
+     non-capturing parentheses, and atomic parentheses. It also applied to some
+     assertions.
+. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
+     information out of configure.ac instead of relying on pcre.h.generic, which
+     is not stored in the repository.
+. Applied Dmitry V. Levin's patch for a more portable method for linking with
+     -lreadline.
+. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
+. Applied Graycode's patch to put the top-level frame on the stack rather
+     than the heap when not using the stack for recursion. This gives a
+     performance improvement in many cases when recursion is not deep.
+. Experimental code added to "pcretest -C" to output the stack frame size.
+ Version 8.21 12-Dec-2011
+ ------------------------
+.  Updating the JIT compiler.
+.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
+     are added as well.
+.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
+     PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
+     calling _pcre_jit_exec. Some extra comments are added.
+.  (*MARK) settings inside atomic groups that do not contain any capturing
+     parentheses, for example, (?>a(*:m)), were not being passed out. This bug
+     was introduced by change 18 for 8.20.
+.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
+     ECMA-262 standard.
+.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
+     erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
+     This bug was probably introduced by change 9 of 8.13.
+.  While fixing 6 above, I noticed that a number of other items were being
+     incorrectly rejected as "not fixed length". This arose partly because newer
+     opcodes had not been added to the fixed-length checking code. I have (a)
+     corrected the bug and added tests for these items, and (b) arranged for an
+     error to occur if an unknown opcode is encountered while checking for fixed
+     length instead of just assuming "not fixed length". The items that were
+     rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
+     (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
+     repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
+.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
+     being incorrectly compiled and would have given unpredicatble results.
+.  A possessively repeated subpattern with minimum repeat count greater than
+     one behaved incorrectly. For example, (A){2,}+ behaved as if it was
+     (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
+     the first (A) could occur when it should not.
+. Add a cast and remove a redundant test from the code.
+. JIT should use pcre_malloc/pcre_free for allocation.
+. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
+     best practice nowadays, and helps with cross-compiling. (If the exec_prefix
+     is anything other than /usr, -L is still shown).
+. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
+. Perl does not support \N without a following name in a [] class; PCRE now
+     also gives an error.
+. If a forward reference was repeated with an upper limit of around 2000,
+     it caused the error "internal error: overran compiling workspace". The
+     maximum number of forward references (including repeats) was limited by the
+     internal workspace, and dependent on the LINK_SIZE. The code has been
+     rewritten so that the workspace expands (via pcre_malloc) if necessary, and
+     the default depends on LINK_SIZE. There is a new upper limit (for safety)
+     of around 200,000 forward references. While doing this, I also speeded up
+     the filling in of repeated forward references.
+. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
+     incorrectly expecting the subject to contain another "a" after the start.
+. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
+     in the match, the SKIP should be ignored. This was not happening; instead
+     the SKIP was being treated as NOMATCH. For patterns such as
+     /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
+     tested.
+. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
+     now much more compatible with Perl, in particular in cases where the result
+     is a non-match for a non-anchored pattern. For example, if
+     /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
+     "m", where previously it did not return a name. A side effect of this
+     change is that for partial matches, the last encountered mark name is
+     returned, as for non matches. A number of tests that were previously not
+     Perl-compatible have been moved into the Perl-compatible test files. The
+     refactoring has had the pleasing side effect of removing one argument from
+     the match() function, thus reducing its stack requirements.
+. If the /S+ option was used in pcretest to study a pattern using JIT,
+     subsequent uses of /S (without +) incorrectly behaved like /S+.
+. Retrieve executable code size support for the JIT compiler and fixing
+     some warnings.
+. A caseless match of a UTF-8 character whose other case uses fewer bytes did
+     not work when the shorter character appeared right at the end of the
+     subject string.
+. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
+     systems.
+. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
+     output it when the /M option is used in pcretest.
+. The CheckMan script was not being included in the distribution. Also, added
+     an explicit "perl" to run Perl scripts from the PrepareRelease script
+     because this is reportedly needed in Windows.
+. If study data was being save in a file and studying had not found a set of
+     "starts with" bytes for the pattern, the data written to the file (though
+     never used) was taken from uninitialized memory and so caused valgrind to
+     complain.
+. Updated RunTest.bat as provided by Sheri Pierce.
+. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
+. Computation of memory usage for the table of capturing group names was
+     giving an unnecessarily large value.
+ Version 8.20 21-Oct-2011
+ ------------------------
+.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
+     a POSIX class. After further experiments with Perl, which convinced me that
+     Perl has bugs and confusions, a closing square bracket is no longer allowed
+     in a POSIX name. This bug also affected patterns with classes that started
+     with full stops.
+.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
+     captured substring, but while checking the failing first alternative,
+     substring 1 is temporarily captured. If the output vector supplied to
+     pcre_exec() was not big enough for this capture, the yield of the function
+     was still zero ("insufficient space for captured substrings"). This cannot
+     be totally fixed without adding another stack variable, which seems a lot
+     of expense for a edge case. However, I have improved the situation in cases
+     such as /(a)(b)x|abc/ matched against "abc", where the return code
+     indicates that fewer than the maximum number of slots in the ovector have
+     been set.
+.  Related to (2) above: when there are more back references in a pattern than
+     slots in the output vector, pcre_exec() uses temporary memory during
+     matching, and copies in the captures as far as possible afterwards. It was
+     using the entire output vector, but this conflicts with the specification
+     that only 2/3 is used for passing back captured substrings. Now it uses
+     only the first 2/3, for compatibility. This is, of course, another edge
+     case.
+.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
+     main code base, and can be used by building with --enable-jit. When this is
+     done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
+     runtime --no-jit option is given.
+.  When the number of matches in a pcre_dfa_exec() run exactly filled the
+     ovector, the return from the function was zero, implying that there were
+     other matches that did not fit. The correct "exactly full" value is now
+     returned.
+.  If a subpattern that was called recursively or as a subroutine contained
+     (*PRUNE) or any other control that caused it to give a non-standard return,
+     invalid errors such as "Error -26 (nested recursion at the same subject
+     position)" or even infinite loops could occur.
+.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
+     computing the minimum length on reaching *ACCEPT, and so ended up with the
+     wrong value of 1 rather than 0. Further investigation indicates that
+     computing a minimum subject length in the presence of *ACCEPT is difficult
+     (think back references, subroutine calls), and so I have changed the code
+     so that no minimum is registered for a pattern that contains *ACCEPT.
+.  If (*THEN) was present in the first (true) branch of a conditional group,
+     it was not handled as intended. [But see 16 below.]
+.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
+     Sheri Pierce.
+. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
+     the first byte in a match must be "a".
+. Change 17 for 8.13 increased the recursion depth for patterns like
+     /a(?:.)*?a/ drastically. I've improved things by remembering whether a
+     pattern contains any instances of (*THEN). If it does not, the old
+     optimizations are restored. It would be nice to do this on a per-group
+     basis, but at the moment that is not feasible.
+. In some environments, the output of pcretest -C is CRLF terminated. This
+     broke RunTest's code that checks for the link size. A single white space
+     character after the value is now allowed for.
+. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
+     For "fr", it uses the Windows-specific input and output files.
+. If (*THEN) appeared in a group that was called recursively or as a
+     subroutine, it did not work as intended. [But see next item.]
+. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
+     pattern fragments (but not containing any | characters). If A and B are
+     matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
+     was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
+     D. In other words, Perl considers parentheses that do not contain any |
+     characters to be part of a surrounding alternative, whereas PCRE was
+     treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
+     differently. PCRE now behaves in the same way as Perl, except in the case
+     of subroutine/recursion calls such as (?1) which have in any case always
+     been different (but PCRE had them first :-).
+. Related to 15 above: Perl does not treat the | in a conditional group as
+     creating alternatives. Such a group is treated in the same way as an
+     ordinary group without any | characters when processing (*THEN). PCRE has
+     been changed to match Perl's behaviour.
+. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
+     RunGrepTest script failed.
+. Change 22 for version 13 caused atomic groups to use more stack. This is
+     inevitable for groups that contain captures, but it can lead to a lot of
+     stack use in large patterns. The old behaviour has been restored for atomic
+     groups that do not contain any capturing parentheses.
+. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
+     suppress the check for a minimum subject length at run time. (If it was
+     given to pcre_exec() or pcre_dfa_exec() it did work.)
+. Fixed an ASCII-dependent infelicity in pcretest that would have made it
+     fail to work when decoding hex characters in data strings in EBCDIC
+     environments.
+. It appears that in at least one Mac OS environment, the isxdigit() function
+     is implemented as a macro that evaluates to its argument more than once,
+     contravening the C 90 Standard (I haven't checked a later standard). There
+     was an instance in pcretest which caused it to go wrong when processing
+     \x{...} escapes in subject strings. The has been rewritten to avoid using
+     things like p++ in the argument of isxdigit().
+ Version 8.13 16-Aug-2011
+ ------------------------
+.  The Unicode data tables have been updated to Unicode 6.0.0.
+.  Two minor typos in pcre_internal.h have been fixed.
+.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
+     pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
+     in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
+.  There were a number of related bugs in the code for matching backrefences
+     caselessly in UTF-8 mode when codes for the characters concerned were
+     different numbers of bytes. For example, U+023A and U+2C65 are an upper
+     and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
+     (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
+     code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
+-byte code at the end of the subject (it thought there wasn't enough data
+     left).
+.  Comprehensive information about what went wrong is now returned by
+     pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
+     as the output vector has at least 2 elements. The offset of the start of
+     the failing character and a reason code are placed in the vector.
+.  When the UTF-8 string check fails for pcre_compile(), the offset that is
+     now returned is for the first byte of the failing character, instead of the
+     last byte inspected. This is an incompatible change, but I hope it is small
+     enough not to be a problem. It makes the returned offset consistent with
+     pcre_exec() and pcre_dfa_exec().
+.  pcretest now gives a text phrase as well as the error number when
+     pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
+     failure, the offset and reason code are output.
+.  When \R was used with a maximizing quantifier it failed to skip backwards
+     over a \r\n pair if the subsequent match failed. Instead, it just skipped
+     back over a single character (\n). This seems wrong (because it treated the
+     two characters as a single entity when going forwards), conflicts with the
+     documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
+     behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
+     has been changed.
+.  Some internal refactoring has changed the processing so that the handling
+     of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
+     time (the PCRE_DOTALL option was changed this way some time ago: version
+.7 change 16). This has made it possible to abolish the OP_OPT op code,
+     which was always a bit of a fudge. It also means that there is one less
+     argument for the match() function, which reduces its stack requirements
+     slightly. This change also fixes an incompatibility with Perl: the pattern
+     (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
+. More internal refactoring has drastically reduced the number of recursive
+     calls to match() for possessively repeated groups such as (abc)++ when
+     using pcre_exec().
+. While implementing 10, a number of bugs in the handling of groups were
+     discovered and fixed:
+     (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
+     (a|)*(?1) gave a compile-time internal error.
+     ((a|)+)+  did not notice that the outer group could match an empty string.
+     (^a|^)+   was not marked as anchored.
+     (.*a|.*)+ was not marked as matching at start or after a newline.
+. Yet more internal refactoring has removed another argument from the match()
+     function. Special calls to this function are now indicated by setting a
+     value in a variable in the "match data" data block.
+. Be more explicit in pcre_study() instead of relying on "default" for
+     opcodes that mean there is no starting character; this means that when new
+     ones are added and accidentally left out of pcre_study(), testing should
+     pick them up.
+. The -s option of pcretest has been documented for ages as being an old
+     synonym of -m (show memory usage). I have changed it to mean "force study
+     for every regex", that is, assume /S for every regex. This is similar to -i
+     and -d etc. It's slightly incompatible, but I'm hoping nobody is still
+     using it. It makes it easier to run collections of tests with and without
+     study enabled, and thereby test pcre_study() more easily. All the standard
+     tests are now run with and without -s (but some patterns can be marked as
+     "never study" - see 20 below).
+. When (*ACCEPT) was used in a subpattern that was called recursively, the
+     restoration of the capturing data to the outer values was not happening
+     correctly.
+. If a recursively called subpattern ended with (*ACCEPT) and matched an
+     empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
+     pattern had matched an empty string, and so incorrectly returned a no
+     match.
+. There was optimizing code for the last branch of non-capturing parentheses,
+     and also for the obeyed branch of a conditional subexpression, which used
+     tail recursion to cut down on stack usage. Unfortunately, now that there is
+     the possibility of (*THEN) occurring in these branches, tail recursion is
+     no longer possible because the return has to be checked for (*THEN). These
+     two optimizations have therefore been removed. [But see 8.20/11 above.]
+. If a pattern containing \R was studied, it was assumed that \R always
+     matched two bytes, thus causing the minimum subject length to be
+     incorrectly computed because \R can also match just one byte.
+. If a pattern containing (*ACCEPT) was studied, the minimum subject length
+     was incorrectly computed.
+. If /S is present twice on a test pattern in pcretest input, it now
+     *disables* studying, thereby overriding the use of -s on the command line
+     (see 14 above). This is necessary for one or two tests to keep the output
+     identical in both cases.
+. When (*ACCEPT) was used in an assertion that matched an empty string and
+     PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
+. When an atomic group that contained a capturing parenthesis was
+     successfully matched, but the branch in which it appeared failed, the
+     capturing was not being forgotten if a higher numbered group was later
+     captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
+     group 1 to "a", when in fact it should be unset. This applied to multi-
+     branched capturing and non-capturing groups, repeated or not, and also to
+     positive assertions (capturing in negative assertions does not happen
+     in PCRE) and also to nested atomic groups.
+. Add the ++ qualifier feature to pcretest, to show the remainder of the
+     subject after a captured substring, to make it easier to tell which of a
+     number of identical substrings has been captured.
+. The way atomic groups are processed by pcre_exec() has been changed so that
+     if they are repeated, backtracking one repetition now resets captured
+     values correctly. For example, if ((?>(a+)b)+aabab) is matched against
+     "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
+     "aaa". Previously, it would have been "a". As part of this code
+     refactoring, the way recursive calls are handled has also been changed.
+. If an assertion condition captured any substrings, they were not passed
+     back unless some other capturing happened later. For example, if
+     (?(?=(a))a) was matched against "a", no capturing was returned.
+. When studying a pattern that contained subroutine calls or assertions,
+     the code for finding the minimum length of a possible match was handling
+     direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
+     group 1 called group 2 while simultaneously a separate group 2 called group
+). A stack overflow occurred in this case. I have fixed this by limiting
+     the recursion depth to 10.
+. Updated RunTest.bat in the distribution to the version supplied by Tom
+     Fortmann. This supports explicit test numbers on the command line, and has
+     argument validation and error reporting.
+. An instance of \X with an unlimited repeat could fail if at any point the
+     first character it looked at was a mark character.
+. Some minor code refactoring concerning Unicode properties and scripts
+     should reduce the stack requirement of match() slightly.
+. Added the '=' option to pcretest to check the setting of unused capturing
+     slots at the end of the pattern, which are documented as being -1, but are
+     not included in the return count.
+. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
+     compiled something random. Now it gives a compile-time error (as does
+     Perl).
+. A *MARK encountered during the processing of a positive assertion is now
+     recorded and passed back (compatible with Perl).
+. If --only-matching or --colour was set on a pcregrep call whose pattern
+     had alternative anchored branches, the search for a second match in a line
+     was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
+     matched the line "0102" twice. The same bug affected patterns that started
+     with a backwards assertion. For example /\b01|\b02/ also matched "0102"
+     twice.
+. Previously, PCRE did not allow quantification of assertions. However, Perl
+     does, and because of capturing effects, quantifying parenthesized
+     assertions may at times be useful. Quantifiers are now allowed for
+     parenthesized assertions.
+. A minor code tidy in pcre_compile() when checking options for \R usage.
+. \g was being checked for fancy things in a character class, when it should
+     just be a literal "g".
+. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
+     appearance of a nested POSIX class supersedes an apparent external class.
+     For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
+     unescaped square brackets may also appear as part of class names. For
+     example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
+     more like Perl. (But see 8.20/1 above.)
+. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
+     was because it thought it was \N{name}, which is not supported).
+. Add minix to OS list not supporting the -S option in pcretest.
+. PCRE tries to detect cases of infinite recursion at compile time, but it
+     cannot analyze patterns in sufficient detail to catch mutual recursions
+     such as ((?1))((?2)). There is now a runtime test that gives an error if a
+     subgroup is called recursively as a subpattern for a second time at the
+     same position in the subject string. In previous releases this might have
+     been caught by the recursion limit, or it might have run out of stack.
+. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
+     happen only once. PCRE was, however incorrectly giving a compile time error
+     "recursive call could loop indefinitely" because it cannot analyze the
+     pattern in sufficient detail. The compile time test no longer happens when
+     PCRE is compiling a conditional subpattern, but actual runaway loops are
+     now caught at runtime (see 40 above).
+. It seems that Perl allows any characters other than a closing parenthesis
+     to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
+     has been changed to be the same.
+. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
+     as not to get warnings when autogen.sh is called. Also changed
+     AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
+. To help people who use pcregrep to scan files containing exceedingly long
+     lines, the following changes have been made:
+     (a) The default value of the buffer size parameter has been increased from
+K to 20K. (The actual buffer used is three times this size.)
+     (b) The default can be changed by ./configure --with-pcregrep-bufsize when
+         PCRE is built.
+     (c) A --buffer-size=n option has been added to pcregrep, to allow the size
+         to be set at run time.
+     (d) Numerical values in pcregrep options can be followed by K or M, for
+         example --buffer-size=50K.
+     (e) If a line being scanned overflows pcregrep's buffer, an error is now
+         given and the return code is set to 2.
+. Add a pointer to the latest mark to the callout data block.
+. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
+     partial match of an empty string instead of no match. This was specific to
+     the use of ".".
+. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
+     complete match instead of a partial match. This bug was dependent on both
+     the PCRE_UTF8 and PCRE_DOTALL options being set.
+. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
+     starting byte set, because \b was not being ignored.
+ Version 8.12 15-Jan-2011
  ------------------------
 .  Fixed some typos in the markup of the man pages, and wrote a script that
      checks for such things as part of the documentation building process.
 .  On a big-endian 64-bit system, pcregrep did not correctly process the
      --match-limit and --recursion-limit options (added for 8.11). In
      particular, this made one of the standard tests fail. (The integer value
      went into the wrong half of a long int.)
 .  If the --colour option was given to pcregrep with -v (invert match), it
      did strange things, either producing crazy output, or crashing. It should,
      of course, ignore a request for colour when reporting lines that do not
      match.
 .  Another pcregrep bug caused similar problems if --colour was specified with
      -M (multiline) and the pattern match finished with a line ending.
 .  In pcregrep, when a pattern that ended with a literal newline sequence was
      matched in multiline mode, the following line was shown as part of the
      match. This seems wrong, so I have changed it.
 .  Another pcregrep bug in multiline mode, when --colour was specified, caused
      the check for further matches in the same line (so they could be coloured)
      to overrun the end of the current line. If another match was found, it was
      incorrectly shown (and then shown again when found in the next line).
 .  If pcregrep was compiled under Windows, there was a reference to the
      function pcregrep_exit() before it was defined. I am assuming this was
      the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
      reported by a user. I've moved the definition above the reference.
  Version 8.11 10-Dec-2010
  ------------------------
-Line 651 
 Version 7.9 11-Apr-09
+Line 2268 
 Version 7.9 11-Apr-09
 .  A pattern that could match an empty string could cause pcregrep to loop; it
      doesn't make sense to accept an empty string match in pcregrep, so I have
      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
-     seems to be how GNU grep behaves.
+     seems to be how GNU grep behaves. [But see later change 40 for release
+.33.]
 .  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
      start or after a newline", because the conditional assertion was not being
-Line 894 
 Version 7.7 07-May-08
+Line 2512 
 Version 7.7 07-May-08
      containing () gave an internal compiling error instead of "reference to
      non-existent subpattern". Fortunately, when the pattern did exist, the
      compiled code was correct. (When scanning forwards to check for the
-     existencd of the subpattern, it was treating the data ']' as terminating
+     existence of the subpattern, it was treating the data ']' as terminating
      the class, so got the count wrong. When actually compiling, the reference
      was subsequently set up correctly.)

 Legend:



Removed from v.588
 


changed lines


 
Added in v.1553
 Legend:



Removed from v.588
 


changed lines


 
Added in v.1553
-Removed from v.588
+Added in v.1553

	ViewVC Help
Powered by ViewVC 1.1.5