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-revision 3 by nigel,
Sat Feb 24 21:38:01 2007 UTC
+revision 1553 by ph10,
Tue Apr 28 11:36:24 2015 UTC
 Line 1
  ChangeLog for PCRE
  ------------------
+ 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
+ ------------------------
+.  (*THEN) was not working properly if there were untried alternatives prior
+     to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
+     backtracked to try for "b" instead of moving to the next alternative branch
+     at the same level (in this case, to look for "c"). The Perl documentation
+     is clear that when (*THEN) is backtracked onto, it goes to the "next
+     alternative in the innermost enclosing group".
+.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
+     such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
+     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
+     (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
+     (*THEN).
+.  If \s appeared in a character class, it removed the VT character from
+     the class, even if it had been included by some previous item, for example
+     in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
+     of \s, but is part of the POSIX "space" class.)
+.  A partial match never returns an empty string (because you can always
+     match an empty string at the end of the subject); however the checking for
+     an empty string was starting at the "start of match" point. This has been
+     changed to the "earliest inspected character" point, because the returned
+     data for a partial match starts at this character. This means that, for
+     example, /(?<=abc)def/ gives a partial match for the subject "abc"
+     (previously it gave "no match").
+.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
+     of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
+     previously a full match would be given. However, setting PCRE_PARTIAL_HARD
+     has an implication that the given string is incomplete (because a partial
+     match is preferred over a full match). For this reason, these items now
+     give a partial match in this situation. [Aside: previously, the one case
+     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
+     match rather than a full match, which was wrong by the old rules, but is
+     now correct.]
+.  There was a bug in the handling of #-introduced comments, recognized when
+     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
+     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
+     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
+     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
+     but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
+     places in pcre_compile().
+.  Related to (6) above, when pcre_compile() was skipping #-introduced
+     comments when looking ahead for named forward references to subpatterns,
+     the only newline sequence it recognized was NL. It now handles newlines
+     according to the set newline convention.
+.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
+     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
+     cater for a lack of strerror(). These oversights have been fixed.
+.  Added --match-limit and --recursion-limit to pcregrep.
+. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
+. When the -o option was used, pcregrep was setting a return code of 1, even
+     when matches were found, and --line-buffered was not being honoured.
+. Added an optional parentheses number to the -o and --only-matching options
+     of pcregrep.
+. Imitating Perl's /g action for multiple matches is tricky when the pattern
+     can match an empty string. The code to do it in pcretest and pcredemo
+     needed fixing:
+     (a) When the newline convention was "crlf", pcretest got it wrong, skipping
+         only one byte after an empty string match just before CRLF (this case
+         just got forgotten; "any" and "anycrlf" were OK).
+     (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
+         mode when an empty string match preceded an ASCII character followed by
+         a non-ASCII character. (The code for advancing by one character rather
+         than one byte was nonsense.)
+     (c) The pcredemo.c sample program did not have any code at all to handle
+         the cases when CRLF is a valid newline sequence.
+. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
+     as a starting offset was within the subject string. There is now a new
+     error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
+     negative or greater than the length of the string. In order to test this,
+     pcretest is extended to allow the setting of negative starting offsets.
+. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
+     starting offset points to the beginning of a UTF-8 character was
+     unnecessarily clumsy. I tidied it up.
+. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
+     bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
+. Nobody had reported that the --include_dir option, which was added in
+     release 7.7 should have been called --include-dir (hyphen, not underscore)
+     for compatibility with GNU grep. I have changed it to --include-dir, but
+     left --include_dir as an undocumented synonym, and the same for
+     --exclude-dir, though that is not available in GNU grep, at least as of
+     release 2.5.4.
+. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
+     characters from a string of bytes) have been redefined so as not to use
+     loops, in order to improve performance in some environments. At the same
+     time, I abstracted some of the common code into auxiliary macros to save
+     repetition (this should not affect the compiled code).
+. If \c was followed by a multibyte UTF-8 character, bad things happened. A
+     compile-time error is now given if \c is not followed by an ASCII
+     character, that is, a byte less than 128. (In EBCDIC mode, the code is
+     different, and any byte value is allowed.)
+. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
+     START_OPTIMIZE option, which is now allowed at compile time - but just
+     passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
+     to pcregrep and other applications that have no direct access to PCRE
+     options. The new /Y option in pcretest sets this option when calling
+     pcre_compile().
+. Change 18 of release 8.01 broke the use of named subpatterns for recursive
+     back references. Groups containing recursive back references were forced to
+     be atomic by that change, but in the case of named groups, the amount of
+     memory required was incorrectly computed, leading to "Failed: internal
+     error: code overflow". This has been fixed.
+. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
+     pcretest.c, to avoid build problems in some Borland environments.
+ Version 8.10 25-Jun-2010
+ ------------------------
+.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
+     THEN.
+.  (*ACCEPT) was not working when inside an atomic group.
+.  Inside a character class, \B is treated as a literal by default, but
+     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
+     causes the error). The code is unchanged, but I tidied the documentation.
+.  Inside a character class, PCRE always treated \R and \X as literals,
+     whereas Perl faults them if its -w option is set. I have changed PCRE so
+     that it faults them when PCRE_EXTRA is set.
+.  Added support for \N, which always matches any character other than
+     newline. (It is the same as "." when PCRE_DOTALL is not set.)
+.  When compiling pcregrep with newer versions of gcc which may have
+     FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
+     declared with attribute warn_unused_result" were given. Just casting the
+     result to (void) does not stop the warnings; a more elaborate fudge is
+     needed. I've used a macro to implement this.
+.  Minor change to pcretest.c to avoid a compiler warning.
+.  Added four artifical Unicode properties to help with an option to make
+     \s etc use properties (see next item). The new properties are: Xan
+     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
+.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
+     use Unicode properties. (*UCP) at the start of a pattern can be used to set
+     this option. Modified pcretest to add /W to test this facility. Added
+     REG_UCP to make it available via the POSIX interface.
+. Added --line-buffered to pcregrep.
+. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
+     studied, and the match started with a letter with a code point greater than
+whose first byte was different to the first byte of the other case of
+     the letter, the other case of this starting letter was not recognized
+     (#976).
+. If a pattern that was studied started with a repeated Unicode property
+     test, for example, \p{Nd}+, there was the theoretical possibility of
+     setting up an incorrect bitmap of starting bytes, but fortunately it could
+     not have actually happened in practice until change 8 above was made (it
+     added property types that matched character-matching opcodes).
+. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
+     possible starting bytes for non-anchored patterns.
+. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
+     \R, and also a number of cases that involve Unicode properties, both
+     explicit and implicit when PCRE_UCP is set.
+. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
+     input, it could crash or give wrong results if characters with values
+     greater than 0xc0 were present in the subject string. (Detail: it assumed
+     UTF-8 input when processing these items.)
+. Added a lot of (int) casts to avoid compiler warnings in systems where
+     size_t is 64-bit (#991).
+. Added a check for running out of memory when PCRE is compiled with
+     --disable-stack-for-recursion (#990).
+. If the last data line in a file for pcretest does not have a newline on
+     the end, a newline was missing in the output.
+. The default pcre_chartables.c file recognizes only ASCII characters (values
+     less than 128) in its various bitmaps. However, there is a facility for
+     generating tables according to the current locale when PCRE is compiled. It
+     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
+     characters, are recognized by isspace() and therefore were getting set in
+     these tables, and indeed these tables seem to approximate to ISO 8859. This
+     caused a problem in UTF-8 mode when pcre_study() was used to create a list
+     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
+     which of course cannot start UTF-8 characters. I have changed the code so
+     that only real ASCII characters (less than 128) and the correct starting
+     bytes for UTF-8 encodings are set for characters greater than 127 when in
+     UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
+     altogether.)
+. Added the /T option to pcretest so as to be able to run tests with non-
+     standard character tables, thus making it possible to include the tests
+     used for 19 above in the standard set of tests.
+. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
+     reference to a subpattern the other side of a comment that contains an
+     opening parenthesis caused either an internal compiling error, or a
+     reference to the wrong subpattern.
+ Version 8.02 19-Mar-2010
+ ------------------------
+.  The Unicode data tables have been updated to Unicode 5.2.0.
+.  Added the option --libs-cpp to pcre-config, but only when C++ support is
+     configured.
+.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
+     original author of that file, following a query about its status.
+.  On systems that do not have stdint.h (e.g. Solaris), check for and include
+     inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
+.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
+     quantifier applied to a forward-referencing subroutine call, could compile
+     incorrect code or give the error "internal error: previously-checked
+     referenced subpattern not found".
+.  Both MS Visual Studio and Symbian OS have problems with initializing
+     variables to point to external functions. For these systems, therefore,
+     pcre_malloc etc. are now initialized to local functions that call the
+     relevant global functions.
+.  There were two entries missing in the vectors called coptable and poptable
+     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
+     I've fixed the data, and added a kludgy way of testing at compile time that
+     the lengths are correct (equal to the number of opcodes).
+.  Following on from 7, I added a similar kludge to check the length of the
+     eint vector in pcreposix.c.
+.  Error texts for pcre_compile() are held as one long string to avoid too
+     much relocation at load time. To find a text, the string is searched,
+     counting zeros. There was no check for running off the end of the string,
+     which could happen if a new error number was added without updating the
+     string.
+. \K gave a compile-time error if it appeared in a lookbehind assersion.
+. \K was not working if it appeared in an atomic group or in a group that
+     was called as a "subroutine", or in an assertion. Perl 5.11 documents that
+     \K is "not well defined" if used in an assertion. PCRE now accepts it if
+     the assertion is positive, but not if it is negative.
+. Change 11 fortuitously reduced the size of the stack frame used in the
+     "match()" function of pcre_exec.c by one pointer. Forthcoming
+     implementation of support for (*MARK) will need an extra pointer on the
+     stack; I have reserved it now, so that the stack frame size does not
+     decrease.
+. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
+     item in branch that calls a recursion is a subroutine call - as in the
+     second branch in the above example - was incorrectly given the compile-
+     time error "recursive call could loop indefinitely" because pcre_compile()
+     was not correctly checking the subroutine for matching a non-empty string.
+. The checks for overrunning compiling workspace could trigger after an
+     overrun had occurred. This is a "should never occur" error, but it can be
+     triggered by pathological patterns such as hundreds of nested parentheses.
+     The checks now trigger 100 bytes before the end of the workspace.
+. Fix typo in configure.ac: "srtoq" should be "strtoq".
+ Version 8.01 19-Jan-2010
+ ------------------------
+.  If a pattern contained a conditional subpattern with only one branch (in
+     particular, this includes all (*DEFINE) patterns), a call to pcre_study()
+     computed the wrong minimum data length (which is of course zero for such
+     subpatterns). This could cause incorrect "no match" results.
+.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
+     the pattern is reset in the first branch, pcre_compile() failed with
+     "internal error: code overflow at offset...". This happened only when
+     the reset was to the original external option setting. (An optimization
+     abstracts leading options settings into an external setting, which was the
+     cause of this.)
+.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
+     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
+     assertion pattern did not match (meaning that the assertion was true), it
+     was incorrectly treated as false if the SKIP had been reached during the
+     matching. This also applied to assertions used as conditions.
+.  If an item that is not supported by pcre_dfa_exec() was encountered in an
+     assertion subpattern, including such a pattern used as a condition,
+     unpredictable results occurred, instead of the error return
+     PCRE_ERROR_DFA_UITEM.
+.  The C++ GlobalReplace function was not working like Perl for the special
+     situation when an empty string is matched. It now does the fancy magic
+     stuff that is necessary.
+.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
+     removed. (These were left over from very, very early versions of PCRE.)
+.  Some cosmetic changes to the code to make life easier when compiling it
+     as part of something else:
+     (a) Change DEBUG to PCRE_DEBUG.
+     (b) In pcre_compile(), rename the member of the "branch_chain" structure
+         called "current" as "current_branch", to prevent a collision with the
+         Linux macro when compiled as a kernel module.
+     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
+         prevent a collision with the Linux macro when compiled as a kernel
+         module.
+.  In pcre_compile() there are some checks for integer overflows that used to
+     cast potentially large values to (double). This has been changed to that
+     when building, a check for int64_t is made, and if it is found, it is used
+     instead, thus avoiding the use of floating point arithmetic. (There is no
+     other use of FP in PCRE.) If int64_t is not found, the fallback is to
+     double.
+.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
+(difference between two addresses compared to an unsigned value).
+. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
+     custom one, because of the following reported problem in Windows:
+       - libbz2 uses the Pascal calling convention (WINAPI) for the functions
+           under Win32.
+       - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
+           therefore missing the function definition.
+       - The compiler thus generates a "C" signature for the test function.
+       - The linker fails to find the "C" function.
+       - PCRE fails to configure if asked to do so against libbz2.
+. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
+     messages were output:
+       Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
+       rerunning libtoolize, to keep the correct libtool macros in-tree.
+       Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
+     I have done both of these things.
+. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
+     most of the time, it *can* run out if it is given a pattern that contains a
+     runaway infinite recursion. I updated the discussion in the pcrestack man
+     page.
+. Now that we have gone to the x.xx style of version numbers, the minor
+     version may start with zero. Using 08 or 09 is a bad idea because users
+     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
+     interpreted as invalid octal numbers. I've updated the previous comment in
+     configure.ac, and also added a check that gives an error if 08 or 09 are
+     used.
+. Change 8.00/11 was not quite complete: code had been accidentally omitted,
+     causing partial matching to fail when the end of the subject matched \W
+     in a UTF-8 pattern where \W was quantified with a minimum of 3.
+. There were some discrepancies between the declarations in pcre_internal.h
+     of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
+     their definitions. The declarations used "const uschar *" and the
+     definitions used USPTR. Even though USPTR is normally defined as "const
+     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
+     reported that: "This difference in casting confuses some C++ compilers, for
+     example, SunCC recognizes above declarations as different functions and
+     generates broken code for hbpcre." I have changed the declarations to use
+     USPTR.
+. GNU libtool is named differently on some systems. The autogen.sh script now
+     tries several variants such as glibtoolize (MacOSX) and libtoolize1x
+     (FreeBSD).
+. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
+     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
+     comment: "Figure out how to create a longlong from a string: strtoll and
+     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
+     instance, but it only takes 2 args instead of 3!"
+. A subtle bug concerned with back references has been fixed by a change of
+     specification, with a corresponding code fix. A pattern such as
+     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
+     refers, was giving matches when it shouldn't. For example, xa=xaaa would
+     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
+     same bug. Such groups have to be quantified to be useful, or contained
+     inside another quantified group. (If there's no repetition, the reference
+     can never match.) The problem arises because, having left the group and
+     moved on to the rest of the pattern, a later failure that backtracks into
+     the group uses the captured value from the final iteration of the group
+     rather than the correct earlier one. I have fixed this in PCRE by forcing
+     any group that contains a reference to itself to be an atomic group; that
+     is, there cannot be any backtracking into it once it has completed. This is
+     similar to recursive and subroutine calls.
+ Version 8.00 19-Oct-09
+ ----------------------
+.  The table for translating pcre_compile() error codes into POSIX error codes
+     was out-of-date, and there was no check on the pcre_compile() error code
+     being within the table. This could lead to an OK return being given in
+     error.
+.  Changed the call to open a subject file in pcregrep from fopen(pathname,
+     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
+     in a Windows environment.
+.  The pcregrep --count option prints the count for each file even when it is
+     zero, as does GNU grep. However, pcregrep was also printing all files when
+     --files-with-matches was added. Now, when both options are given, it prints
+     counts only for those files that have at least one match. (GNU grep just
+     prints the file name in this circumstance, but including the count seems
+     more useful - otherwise, why use --count?) Also ensured that the
+     combination -clh just lists non-zero counts, with no names.
+.  The long form of the pcregrep -F option was incorrectly implemented as
+     --fixed_strings instead of --fixed-strings. This is an incompatible change,
+     but it seems right to fix it, and I didn't think it was worth preserving
+     the old behaviour.
+.  The command line items --regex=pattern and --regexp=pattern were not
+     recognized by pcregrep, which required --regex pattern or --regexp pattern
+     (with a space rather than an '='). The man page documented the '=' forms,
+     which are compatible with GNU grep; these now work.
+.  No libpcreposix.pc file was created for pkg-config; there was just
+     libpcre.pc and libpcrecpp.pc. The omission has been rectified.
+.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
+     when UCP support is not needed, by modifying the Python script that
+     generates it from Unicode data files. This should not matter if the module
+     is correctly used as a library, but I received one complaint about 50K of
+     unwanted data. My guess is that the person linked everything into his
+     program rather than using a library. Anyway, it does no harm.
+.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
+     was a minimum greater than 1 for a wide character in a possessive
+     repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
+     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
+     character. Chaos in the form of incorrect output or a compiling loop could
+     result.
+.  The restrictions on what a pattern can contain when partial matching is
+     requested for pcre_exec() have been removed. All patterns can now be
+     partially matched by this function. In addition, if there are at least two
+     slots in the offset vector, the offset of the earliest inspected character
+     for the match and the offset of the end of the subject are set in them when
+     PCRE_ERROR_PARTIAL is returned.
+. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
+     synonymous with PCRE_PARTIAL, for backwards compatibility, and
+     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
+     and may be more useful for multi-segment matching.
+. Partial matching with pcre_exec() is now more intuitive. A partial match
+     used to be given if ever the end of the subject was reached; now it is
+     given only if matching could not proceed because another character was
+     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
+     string "Z", which now yields "no match" instead of "partial match". In the
+     case of pcre_dfa_exec(), "no match" is given if every matching path for the
+     final character ended with (*FAIL).
+. Restarting a match using pcre_dfa_exec() after a partial match did not work
+     if the pattern had a "must contain" character that was already found in the
+     earlier partial match, unless partial matching was again requested. For
+     example, with the pattern /dog.(body)?/, the "must contain" character is
+     "g". If the first part-match was for the string "dog", restarting with
+     "sbody" failed. This bug has been fixed.
+. The string returned by pcre_dfa_exec() after a partial match has been
+     changed so that it starts at the first inspected character rather than the
+     first character of the match. This makes a difference only if the pattern
+     starts with a lookbehind assertion or \b or \B (\K is not supported by
+     pcre_dfa_exec()). It's an incompatible change, but it makes the two
+     matching functions compatible, and I think it's the right thing to do.
+. Added a pcredemo man page, created automatically from the pcredemo.c file,
+     so that the demonstration program is easily available in environments where
+     PCRE has not been installed from source.
+. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
+     libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
+     library.
+. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
+     It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
+     is not the first non-POSIX option to be added. Clearly some people find
+     these options useful.
+. If a caller to the POSIX matching function regexec() passes a non-zero
+     value for nmatch with a NULL value for pmatch, the value of
+     nmatch is forced to zero.
+. RunGrepTest did not have a test for the availability of the -u option of
+     the diff command, as RunTest does. It now checks in the same way as
+     RunTest, and also checks for the -b option.
+. If an odd number of negated classes containing just a single character
+     interposed, within parentheses, between a forward reference to a named
+     subpattern and the definition of the subpattern, compilation crashed with
+     an internal error, complaining that it could not find the referenced
+     subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
+     [The bug was that it was starting one character too far in when skipping
+     over the character class, thus treating the ] as data rather than
+     terminating the class. This meant it could skip too much.]
+. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
+     /g option in pcretest when the pattern contains \K, which makes it possible
+     to have an empty string match not at the start, even when the pattern is
+     anchored. Updated pcretest and pcredemo to use this option.
+. If the maximum number of capturing subpatterns in a recursion was greater
+     than the maximum at the outer level, the higher number was returned, but
+     with unset values at the outer level. The correct (outer level) value is
+     now given.
+. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
+     PCRE did not set those parentheses (unlike Perl). I have now found a way to
+     make it do so. The string so far is captured, making this feature
+     compatible with Perl.
+. The tests have been re-organized, adding tests 11 and 12, to make it
+     possible to check the Perl 5.10 features against Perl 5.10.
+. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
+     pattern matches a fixed length string. PCRE did not allow this; now it
+     does. Neither allows recursion.
+. I finally figured out how to implement a request to provide the minimum
+     length of subject string that was needed in order to match a given pattern.
+     (It was back references and recursion that I had previously got hung up
+     on.) This code has now been added to pcre_study(); it finds a lower bound
+     to the length of subject needed. It is not necessarily the greatest lower
+     bound, but using it to avoid searching strings that are too short does give
+     some useful speed-ups. The value is available to calling programs via
+     pcre_fullinfo().
+. While implementing 25, I discovered to my embarrassment that pcretest had
+     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
+     study optimizations had never been tested with that matching function.
+     Oops. What is worse, even when it was passed study data, there was a bug in
+     pcre_dfa_exec() that meant it never actually used it. Double oops. There
+     were also very few tests of studied patterns with pcre_dfa_exec().
+. If (?| is used to create subpatterns with duplicate numbers, they are now
+     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
+     on the other side of the coin, they are no longer allowed to have different
+     names, because these cannot be distinguished in PCRE, and this has caused
+     confusion. (This is a difference from Perl.)
+. When duplicate subpattern names are present (necessarily with different
+     numbers, as required by 27 above), and a test is made by name in a
+     conditional pattern, either for a subpattern having been matched, or for
+     recursion in such a pattern, all the associated numbered subpatterns are
+     tested, and the overall condition is true if the condition is true for any
+     one of them. This is the way Perl works, and is also more like the way
+     testing by number works.
+ Version 7.9 11-Apr-09
+ ---------------------
+.  When building with support for bzlib/zlib (pcregrep) and/or readline
+     (pcretest), all targets were linked against these libraries. This included
+     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
+     libraries. This caused unwanted dependencies to be created. This problem
+     has been fixed, and now only pcregrep is linked with bzlib/zlib and only
+     pcretest is linked with readline.
+.  The "typedef int BOOL" in pcre_internal.h that was included inside the
+     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
+     moved outside it again, because FALSE and TRUE are already defined in AIX,
+     but BOOL is not.
+.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
+     PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
+.  The pcregrep documentation said spaces were inserted as well as colons (or
+     hyphens) following file names and line numbers when outputting matching
+     lines. This is not true; no spaces are inserted. I have also clarified the
+     wording for the --colour (or --color) option.
+.  In pcregrep, when --colour was used with -o, the list of matching strings
+     was not coloured; this is different to GNU grep, so I have changed it to be
+     the same.
+.  When --colo(u)r was used in pcregrep, only the first matching substring in
+     each matching line was coloured. Now it goes on to look for further matches
+     of any of the test patterns, which is the same behaviour as GNU grep.
+.  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. [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
+     correctly handled. The rule now is that both the assertion and what follows
+     in the first alternative must satisfy the test.
+.  If auto-callout was enabled in a pattern with a conditional group whose
+     condition was an assertion, PCRE could crash during matching, both with
+     pcre_exec() and pcre_dfa_exec().
+. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
+     used for matching.
+. Unicode property support in character classes was not working for
+     characters (bytes) greater than 127 when not in UTF-8 mode.
+. Added the -M command line option to pcretest.
+. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
+. Added the PCRE_NO_START_OPTIMIZE match-time option.
+. Added comments and documentation about mis-use of no_arg in the C++
+     wrapper.
+. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
+     from Martin Jerabek that uses macro names for all relevant character and
+     string constants.
+. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
+     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
+     SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
+     these, but not everybody uses configure.
+. A conditional group that had only one branch was not being correctly
+     recognized as an item that could match an empty string. This meant that an
+     enclosing group might also not be so recognized, causing infinite looping
+     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
+     with the subject "ab", where knowledge that the repeated group can match
+     nothing is needed in order to break the loop.
+. If a pattern that was compiled with callouts was matched using pcre_dfa_
+     exec(), but without supplying a callout function, matching went wrong.
+. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
+     leak if the size of the offset vector was greater than 30. When the vector
+     is smaller, the saved offsets during recursion go onto a local stack
+     vector, but for larger vectors malloc() is used. It was failing to free
+     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
+     error, in fact).
+. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
+     heapframe that is used only when UTF-8 support is enabled. This caused no
+     problem, but was untidy.
+. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
+     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
+     included within another project.
+. Steven Van Ingelgem's patches to add more options to the CMake support,
+     slightly modified by me:
+       (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
+           not building pcregrep.
+       (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
+           if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
+. Forward references, both numeric and by name, in patterns that made use of
+     duplicate group numbers, could behave incorrectly or give incorrect errors,
+     because when scanning forward to find the reference group, PCRE was not
+     taking into account the duplicate group numbers. A pattern such as
+     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
+. Changed a few more instances of "const unsigned char *" to USPTR, making
+     the feature of a custom pointer more persuasive (as requested by a user).
+. Wrapped the definitions of fileno and isatty for Windows, which appear in
+     pcretest.c, inside #ifndefs, because it seems they are sometimes already
+     pre-defined.
+. Added support for (*UTF8) at the start of a pattern.
+. Arrange for flags added by the "release type" setting in CMake to be shown
+     in the configuration summary.
+ Version 7.8 05-Sep-08
+ ---------------------
+.  Replaced UCP searching code with optimized version as implemented for Ad
+     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
+     stage table and inline lookup instead of a function, giving speed ups of 2
+     to 5 times on some simple patterns that I tested. Permission was given to
+     distribute the MultiStage2.py script that generates the tables (it's not in
+     the tarball, but is in the Subversion repository).
+.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
+     scripts.
+.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
+     a group with a zero qualifier. The result of the study could be incorrect,
+     or the function might crash, depending on the pattern.
+.  Caseless matching was not working for non-ASCII characters in back
+     references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
+     It now works when Unicode Property Support is available.
+.  In pcretest, an escape such as \x{de} in the data was always generating
+     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
+     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
+     truncation.
+.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
+.  Added two (int) casts to pcregrep when printing the difference of two
+     pointers, in case they are 64-bit values.
+.  Added comments about Mac OS X stack usage to the pcrestack man page and to
+     test 2 if it fails.
+.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
+     and a #define of that name to empty if it is not externally set. This is to
+     allow users of MSVC to set it if necessary.
+. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
+     the convenience functions in the pcre_get.c source file.
+. An option change at the start of a pattern that had top-level alternatives
+     could cause overwriting and/or a crash. This command provoked a crash in
+     some environments:
+       printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
+     This potential security problem was recorded as CVE-2008-2371.
+. For a pattern where the match had to start at the beginning or immediately
+     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
+     pcre_dfa_exec() could read past the end of the passed subject if there was
+     no match. To help with detecting such bugs (e.g. with valgrind), I modified
+     pcretest so that it places the subject at the end of its malloc-ed buffer.
+. The change to pcretest in 12 above threw up a couple more cases when pcre_
+     exec() might read past the end of the data buffer in UTF-8 mode.
+. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
+     the data contained the byte 0x85 as part of a UTF-8 character within its
+     first line. This applied both to normal and DFA matching.
+. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
+     /^[^d]*?$/8 failed to match "abc".
+. Added a missing copyright notice to pcrecpp_internal.h.
+. Make it more clear in the documentation that values returned from
+     pcre_exec() in ovector are byte offsets, not character counts.
+. Tidied a few places to stop certain compilers from issuing warnings.
+. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
+     supplied by Stefan Weber. I made a further small update for 7.8 because
+     there is a change of source arrangements: the pcre_searchfuncs.c module is
+     replaced by pcre_ucd.c.
+ Version 7.7 07-May-08
+ ---------------------
+.  Applied Craig's patch to sort out a long long problem: "If we can't convert
+     a string to a long long, pretend we don't even have a long long." This is
+     done by checking for the strtoq, strtoll, and _strtoi64 functions.
+.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
+     pre-7.6 versions, which defined a global no_arg variable instead of putting
+     it in the RE class. (See also #8 below.)
+.  Remove a line of dead code, identified by coverity and reported by Nuno
+     Lopes.
+.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
+     (1) The include/exclude patterns were being applied to the whole pathnames
+         of files, instead of just to the final components.
+     (2) If there was more than one level of directory, the subdirectories were
+         skipped unless they satisfied the include/exclude conditions. This is
+         inconsistent with GNU grep (and could even be seen as contrary to the
+         pcregrep specification - which I improved to make it absolutely clear).
+         The action now is always to scan all levels of directory, and just
+         apply the include/exclude patterns to regular files.
+.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
+     --exclude_dir in the tests to avoid scanning .svn directories.
+.  Applied Craig's patch to the QuoteMeta function so that it escapes the
+     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
+     doesn't support NULs in patterns.
+.  Added some missing "const"s to declarations of static tables in
+     pcre_compile.c and pcre_dfa_exec.c.
+.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
+     caused by fix #2  above. (Subsequently also a second patch to fix the
+     first patch. And a third patch - this was a messy problem.)
+.  Applied Craig's patch to remove the use of push_back().
+. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
+     matching function regexec().
+. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
+     which, however, unlike Perl's \g{...}, are subroutine calls, not back
+     references. PCRE supports relative numbers with this syntax (I don't think
+     Oniguruma does).
+. Previously, a group with a zero repeat such as (...){0} was completely
+     omitted from the compiled regex. However, this means that if the group
+     was called as a subroutine from elsewhere in the pattern, things went wrong
+     (an internal error was given). Such groups are now left in the compiled
+     pattern, with a new opcode that causes them to be skipped at execution
+     time.
+. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
+     to the way PCRE behaves:
+     (a) A lone ] character is dis-allowed (Perl treats it as data).
+     (b) A back reference to an unmatched subpattern matches an empty string
+         (Perl fails the current match path).
+     (c) A data ] in a character class must be notated as \] because if the
+         first data character in a class is ], it defines an empty class. (In
+         Perl it is not possible to have an empty class.) The empty class []
+         never matches; it forces failure and is equivalent to (*FAIL) or (?!).
+         The negative empty class [^] matches any one character, independently
+         of the DOTALL setting.
+. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
+     non-existent subpattern following a character class starting with ']' and
+     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
+     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.)
+. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
+     it was being rejected as not supported by pcre_dfa_exec(), even though
+     other assertions are supported. I have made pcre_dfa_exec() support
+     (*FAIL).
+. The implementation of 13c above involved the invention of a new opcode,
+     OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
+     cannot be changed at match time, I realized I could make a small
+     improvement to matching performance by compiling OP_ALLANY instead of
+     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
+     on the OP_ANY path.
+. Compiling pcretest on Windows with readline support failed without the
+     following two fixes: (1) Make the unistd.h include conditional on
+     HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
+. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
+     ncurses library to be included for pcretest when ReadLine support is
+     requested, but also to allow for it to be overridden. This patch came from
+     Daniel Bergstr�m.
+. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
+     as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
+     any errors with the current Unicode tables. Thanks to Peter Kankowski for
+     spotting this.
+ Version 7.6 28-Jan-08
+ ---------------------
+.  A character class containing a very large number of characters with
+     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
+     overflow.
+.  Patch to cut out the "long long" test in pcrecpp_unittest when
+     HAVE_LONG_LONG is not defined.
+.  Applied Christian Ehrlicher's patch to update the CMake build files to
+     bring them up to date and include new features. This patch includes:
+     - Fixed PH's badly added libz and libbz2 support.
+     - Fixed a problem with static linking.
+     - Added pcredemo. [But later removed - see 7 below.]
+     - Fixed dftables problem and added an option.
+     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
+         HAVE_LONG_LONG.
+     - Added readline support for pcretest.
+     - Added an listing of the option settings after cmake has run.
+.  A user submitted a patch to Makefile that makes it easy to create
+     "pcre.dll" under mingw when using Configure/Make. I added stuff to
+     Makefile.am that cause it to include this special target, without
+     affecting anything else. Note that the same mingw target plus all
+     the other distribution libraries and programs are now supported
+     when configuring with CMake (see 6 below) instead of with
+     Configure/Make.
+.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
+     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
+     exported in the Windows port". It has not yet been confirmed that the patch
+     solves the problem, but it does no harm.
+.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
+     NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
+     with CMake, and also correct the comment about stack recursion.
+.  Remove the automatic building of pcredemo from the ./configure system and
+     from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
+     of a program that users should build themselves after PCRE is installed, so
+     building it automatically is not really right. What is more, it gave
+     trouble in some build environments.
+.  Further tidies to CMakeLists.txt from Sheri and Christian.
+ Version 7.5 10-Jan-08
+ ---------------------
+.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
+     values in parens when parsing an RE using the C++ wrapper."
+.  Negative specials like \S did not work in character classes in UTF-8 mode.
+     Characters greater than 255 were excluded from the class instead of being
+     included.
+.  The same bug as (2) above applied to negated POSIX classes such as
+     [:^space:].
+.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
+     defined or documented. It seems to have been a typo for PCRE_STATIC, so
+     I have changed it.
+.  The construct (?&) was not diagnosed as a syntax error (it referenced the
+     first named subpattern) and a construct such as (?&a) would reference the
+     first named subpattern whose name started with "a" (in other words, the
+     length check was missing). Both these problems are fixed. "Subpattern name
+     expected" is now given for (?&) (a zero-length name), and this patch also
+     makes it give the same error for \k'' (previously it complained that that
+     was a reference to a non-existent subpattern).
+.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
+     this is right because (?- can be followed by option settings as well as by
+     digits. I have, however, made the messages clearer.
+.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
+     than the number used in the conditional) now cause a compile-time error.
+     This is actually not compatible with Perl, which accepts such patterns, but
+     treats the conditional as always being FALSE (as PCRE used to), but it
+     seems to me that giving a diagnostic is better.
+.  Change "alphameric" to the more common word "alphanumeric" in comments
+     and messages.
+.  Fix two occurrences of "backslash" in comments that should have been
+     "backspace".
+. Remove two redundant lines of code that can never be obeyed (their function
+     was moved elsewhere).
+. The program that makes PCRE's Unicode character property table had a bug
+     which caused it to generate incorrect table entries for sequences of
+     characters that have the same character type, but are in different scripts.
+     It amalgamated them into a single range, with the script of the first of
+     them. In other words, some characters were in the wrong script. There were
+     thirteen such cases, affecting characters in the following ranges:
+       U+002b0 - U+002c1
+       U+0060c - U+0060d
+       U+0061e - U+00612
+       U+0064b - U+0065e
+       U+0074d - U+0076d
+       U+01800 - U+01805
+       U+01d00 - U+01d77
+       U+01d9b - U+01dbf
+       U+0200b - U+0200f
+       U+030fc - U+030fe
+       U+03260 - U+0327f
+       U+0fb46 - U+0fbb1
+       U+10450 - U+1049d
+. The -o option (show only the matching part of a line) for pcregrep was not
+     compatible with GNU grep in that, if there was more than one match in a
+     line, it showed only the first of them. It now behaves in the same way as
+     GNU grep.
+. If the -o and -v options were combined for pcregrep, it printed a blank
+     line for every non-matching line. GNU grep prints nothing, and pcregrep now
+     does the same. The return code can be used to tell if there were any
+     non-matching lines.
+. Added --file-offsets and --line-offsets to pcregrep.
+. The pattern (?=something)(?R) was not being diagnosed as a potentially
+     infinitely looping recursion. The bug was that positive lookaheads were not
+     being skipped when checking for a possible empty match (negative lookaheads
+     and both kinds of lookbehind were skipped).
+. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
+     inclusion of <windows.h> to before rather than after the definition of
+     INVALID_FILE_ATTRIBUTES (patch from David Byron).
+. Specifying a possessive quantifier with a specific limit for a Unicode
+     character property caused pcre_compile() to compile bad code, which led at
+     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
+     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
+     caused the error; without that there was no problem.
+. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
+. Added --enable-pcretest-libreadline.
+. In pcrecpp.cc, the variable 'count' was incremented twice in
+     RE::GlobalReplace(). As a result, the number of replacements returned was
+     double what it should be. I removed one of the increments, but Craig sent a
+     later patch that removed the other one (the right fix) and added unit tests
+     that check the return values (which was not done before).
+. Several CMake things:
+     (1) Arranged that, when cmake is used on Unix, the libraries end up with
+         the names libpcre and libpcreposix, not just pcre and pcreposix.
+     (2) The above change means that pcretest and pcregrep are now correctly
+         linked with the newly-built libraries, not previously installed ones.
+     (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
+. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
+     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
+     UTF-8 newline character). The key issue is that the pattern starts .*;
+     this means that the match must be either at the beginning, or after a
+     newline. The bug was in the code for advancing after a failed match and
+     checking that the new position followed a newline. It was not taking
+     account of UTF-8 characters correctly.
+. PCRE was behaving differently from Perl in the way it recognized POSIX
+     character classes. PCRE was not treating the sequence [:...:] as a
+     character class unless the ... were all letters. Perl, however, seems to
+     allow any characters between [: and :], though of course it rejects as
+     unknown any "names" that contain non-letters, because all the known class
+     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
+     for example, whereas PCRE did not - it did not recognize a POSIX character
+     class. This seemed a bit dangerous, so the code has been changed to be
+     closer to Perl. The behaviour is not identical to Perl, because PCRE will
+     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
+     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
+     Perl does, and where it didn't before.
+. Rewrite so as to remove the single use of %n from pcregrep because in some
+     Windows environments %n is disabled by default.
+ Version 7.4 21-Sep-07
+ ---------------------
+.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
+     means that a class such as [\s] counted as "explicit reference to CR or
+     LF". That isn't really right - the whole point of the change was to try to
+     help when there was an actual mention of one of the two characters. So now
+     the change happens only if \r or \n (or a literal CR or LF) character is
+     encountered.
+.  The 32-bit options word was also used for 6 internal flags, but the numbers
+     of both had grown to the point where there were only 3 bits left.
+     Fortunately, there was spare space in the data structure, and so I have
+     moved the internal flags into a new 16-bit field to free up more option
+     bits.
+.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
+     but did not set the internal JCHANGED flag - either of these is enough to
+     control the way the "get" function works - but the PCRE_INFO_JCHANGED
+     facility is supposed to tell if (?J) was ever used, so now (?J) at the
+     start sets both bits.
+.  Added options (at build time, compile time, exec time) to change \R from
+     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
+.  doc/pcresyntax.html was missing from the distribution.
+.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
+     compatibility, even though it is no longer used.
+.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
+     strtoull to pcrecpp.cc to select the available functions in WIN32 when the
+     windows.h file is present (where different names are used). [This was
+     reversed later after testing - see 16 below.]
+.  Changed all #include <config.h> to #include "config.h". There were also
+     some further <pcre.h> cases that I changed to "pcre.h".
+.  When pcregrep was used with the --colour option, it missed the line ending
+     sequence off the lines that it output.
+. It was pointed out to me that arrays of string pointers cause lots of
+     relocations when a shared library is dynamically loaded. A technique of
+     using a single long string with a table of offsets can drastically reduce
+     these. I have refactored PCRE in four places to do this. The result is
+     dramatic:
+       Originally:                          290
+       After changing UCP table:            187
+       After changing error message table:   43
+       After changing table of "verbs"       36
+       After changing table of Posix names   22
+     Thanks to the folks working on Gregex for glib for this insight.
+. --disable-stack-for-recursion caused compiling to fail unless -enable-
+     unicode-properties was also set.
+. Updated the tests so that they work when \R is defaulted to ANYCRLF.
+. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
+     checked only for CRLF.
+. Added casts to pcretest.c to avoid compiler warnings.
+. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
+. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
+     and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
+     entirely. This removes changes made in 7 above.
+. The CMake files have been updated, and there is now more information about
+     building with CMake in the NON-UNIX-USE document.
+ Version 7.3 28-Aug-07
+ ---------------------
+. In the rejigging of the build system that eventually resulted in 7.1, the
+     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
+     brackets there is not right, since it causes compilers to look for an
+     installed pcre.h, not the version that is in the source that is being
+     compiled (which of course may be different). I have changed it back to:
+       #include "pcre.h"
+     I have a vague recollection that the change was concerned with compiling in
+     different directories, but in the new build system, that is taken care of
+     by the VPATH setting the Makefile.
+. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
+     when the subject happened to end in the byte 0x85 (e.g. if the last
+     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
+     characters but of course it shouldn't be taken as a newline when it is part
+     of another character. The bug was that, for an unlimited repeat of . in
+     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
+     characters when looking for a newline.
+. A small performance improvement in the DOTALL UTF-8 mode .* case.
+. Debugging: adjusted the names of opcodes for different kinds of parentheses
+     in debug output.
+. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
+     long printing in the pcrecpp unittest when running under MinGW.
+. ESC_K was left out of the EBCDIC table.
+. Change 7.0/38 introduced a new limit on the number of nested non-capturing
+     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
+     limit also applies to "virtual nesting" when a pattern is recursive, and in
+     this case 1000 isn't so big. I have been able to remove this limit at the
+     expense of backing off one optimization in certain circumstances. Normally,
+     when pcre_exec() would call its internal match() function recursively and
+     immediately return the result unconditionally, it uses a "tail recursion"
+     feature to save stack. However, when a subpattern that can match an empty
+     string has an unlimited repetition quantifier, it no longer makes this
+     optimization. That gives it a stack frame in which to save the data for
+     checking that an empty string has been matched. Previously this was taken
+     from the 1000-entry workspace that had been reserved. So now there is no
+     explicit limit, but more stack is used.
+. Applied Daniel's patches to solve problems with the import/export magic
+     syntax that is required for Windows, and which was going wrong for the
+     pcreposix and pcrecpp parts of the library. These were overlooked when this
+     problem was solved for the main library.
+. There were some crude static tests to avoid integer overflow when computing
+     the size of patterns that contain repeated groups with explicit upper
+     limits. As the maximum quantifier is 65535, the maximum group length was
+     set at 30,000 so that the product of these two numbers did not overflow a
+-bit integer. However, it turns out that people want to use groups that
+     are longer than 30,000 bytes (though not repeat them that many times).
+     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
+     made it possible to implement the integer overflow checks in a much more
+     dynamic way, which I have now done. The artificial limitation on group
+     length has been removed - we now have only the limit on the total length of
+     the compiled pattern, which depends on the LINK_SIZE setting.
+. Fixed a bug in the documentation for get/copy named substring when
+     duplicate names are permitted. If none of the named substrings are set, the
+     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
+     empty string.
+. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
+     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
+     because the ] is interpreted as the first data character and the
+     terminating ] is not found. PCRE has been made compatible with Perl in this
+     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
+     cause memory overwriting.
+. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
+     string has been matched (to stop an infinite loop). It was not recognizing
+     a conditional subpattern that could match an empty string if that
+     subpattern was within another subpattern. For example, it looped when
+     trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
+     condition was not nested. This bug has been fixed.
+. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
+     past the start of the subject in the presence of bytes with the top bit
+     set, for example "\x8aBCD".
+. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
+     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
+. Optimized (?!) to (*FAIL).
+. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
+     This restricts code points to be within the range 0 to 0x10FFFF, excluding
+     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
+     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
+     does: it's just the validity check that is more restrictive.
+. Inserted checks for integer overflows during escape sequence (backslash)
+     processing, and also fixed erroneous offset values for syntax errors during
+     backslash processing.
+. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
+     for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
+. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
+     caused an overrun.
+. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
+     something other than just ASCII characters) inside a group that had an
+     unlimited repeat caused a loop at compile time (while checking to see
+     whether the group could match an empty string).
+. Debugging a pattern containing \p or \P could cause a crash. For example,
+     [\P{Any}] did so. (Error in the code for printing property names.)
+. An orphan \E inside a character class could cause a crash.
+. A repeated capturing bracket such as (A)? could cause a wild memory
+     reference during compilation.
+. There are several functions in pcre_compile() that scan along a compiled
+     expression for various reasons (e.g. to see if it's fixed length for look
+     behind). There were bugs in these functions when a repeated \p or \P was
+     present in the pattern. These operators have additional parameters compared
+     with \d, etc, and these were not being taken into account when moving along
+     the compiled data. Specifically:
+     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
+         length.
+     (b) An item such as \pL+ within a repeated group could cause crashes or
+         loops.
+     (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
+         "reference to non-existent subpattern" error.
+     (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
+. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
+     characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
+. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
+. Patterns such as [\P{Yi}A] which include \p or \P and just one other
+     character were causing crashes (broken optimization).
+. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
+     \p or \P) caused a compile-time loop.
+. More problems have arisen in unanchored patterns when CRLF is a valid line
+     break. For example, the unstudied pattern [\r\n]A does not match the string
+     "\r\nA" because change 7.0/46 below moves the current point on by two
+     characters after failing to match at the start. However, the pattern \nA
+     *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
+     the same is true. There doesn't seem any very clean way out of this, but
+     what I have chosen to do makes the common cases work: PCRE now takes note
+     of whether there can be an explicit match for \r or \n anywhere in the
+     pattern, and if so, 7.0/46 no longer applies. As part of this change,
+     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
+     pattern has explicit CR or LF references.
+. Added (*CR) etc for changing newline setting at start of pattern.
+ Version 7.2 19-Jun-07
+ ---------------------
+. If the fr_FR locale cannot be found for test 3, try the "french" locale,
+     which is apparently normally available under Windows.
+. Re-jig the pcregrep tests with different newline settings in an attempt
+     to make them independent of the local environment's newline setting.
+. Add code to configure.ac to remove -g from the CFLAGS default settings.
+. Some of the "internals" tests were previously cut out when the link size
+     was not 2, because the output contained actual offsets. The recent new
+     "Z" feature of pcretest means that these can be cut out, making the tests
+     usable with all link sizes.
+. Implemented Stan Switzer's goto replacement for longjmp() when not using
+     stack recursion. This gives a massive performance boost under BSD, but just
+     a small improvement under Linux. However, it saves one field in the frame
+     in all cases.
+. Added more features from the forthcoming Perl 5.10:
+     (a) (?-n) (where n is a string of digits) is a relative subroutine or
+         recursion call. It refers to the nth most recently opened parentheses.
+     (b) (?+n) is also a relative subroutine call; it refers to the nth next
+         to be opened parentheses.
+     (c) Conditions that refer to capturing parentheses can be specified
+         relatively, for example, (?(-2)... or (?(+3)...
+     (d) \K resets the start of the current match so that everything before
+         is not part of it.
+     (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
+     (f) \g{name} is another synonym - part of Perl 5.10's unification of
+         reference syntax.
+     (g) (?| introduces a group in which the numbering of parentheses in each
+         alternative starts with the same number.
+     (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
+. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
+     PCRE_INFO_JCHANGED.
+. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
+     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
+     for detecting groups that can match an empty string.
+. A pattern with a very large number of alternatives (more than several
+     hundred) was running out of internal workspace during the pre-compile
+     phase, where pcre_compile() figures out how much memory will be needed. A
+     bit of new cunning has reduced the workspace needed for groups with
+     alternatives. The 1000-alternative test pattern now uses 12 bytes of
+     workspace instead of running out of the 4096 that are available.
+. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
+. Applied patch from Google to remove an optimization that didn't quite work.
+     The report of the bug said:
+       pcrecpp::RE("a*").FullMatch("aaa") matches, while
+       pcrecpp::RE("a*?").FullMatch("aaa") does not, and
+       pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
+. If \p or \P was used in non-UTF-8 mode on a character greater than 127
+     it matched the wrong number of bytes.
+ Version 7.1 24-Apr-07
+ ---------------------
+. Applied Bob Rossi and Daniel G's patches to convert the build system to one
+     that is more "standard", making use of automake and other Autotools. There
+     is some re-arrangement of the files and adjustment of comments consequent
+     on this.
+. Part of the patch fixed a problem with the pcregrep tests. The test of -r
+     for recursive directory scanning broke on some systems because the files
+     are not scanned in any specific order and on different systems the order
+     was different. A call to "sort" has been inserted into RunGrepTest for the
+     approprate test as a short-term fix. In the longer term there may be an
+     alternative.
+. I had an email from Eric Raymond about problems translating some of PCRE's
+     man pages to HTML (despite the fact that I distribute HTML pages, some
+     people do their own conversions for various reasons). The problems
+     concerned the use of low-level troff macros .br and .in. I have therefore
+     removed all such uses from the man pages (some were redundant, some could
+     be replaced by .nf/.fi pairs). The 132html script that I use to generate
+     HTML has been updated to handle .nf/.fi and to complain if it encounters
+     .br or .in.
+. Updated comments in configure.ac that get placed in config.h.in and also
+     arranged for config.h to be included in the distribution, with the name
+     config.h.generic, for the benefit of those who have to compile without
+     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
+. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
+     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
+     makevp.bat for the current PCRE, using the additional files
+     makevp_c.txt, makevp_l.txt, and pcregexp.pas.
+. A Windows user reported a minor discrepancy with test 2, which turned out
+     to be caused by a trailing space on an input line that had got lost in his
+     copy. The trailing space was an accident, so I've just removed it.
+. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
+     that is needed.
+. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
+     as "const" (a) because they are and (b) because it helps the PHP
+     maintainers who have recently made a script to detect big data structures
+     in the php code that should be moved to the .rodata section. I remembered
+     to update Builducptable as well, so it won't revert if ucptable.h is ever
+     re-created.
+. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
+     pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
+     order to be able to cut out the UTF-8 tables in the latter when UTF-8
+     support is not required. This saves 1.5-2K of code, which is important in
+     some applications.
+     Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
+     so as not to refer to the tables, even though these functions will never be
+     called when UTF-8 support is disabled. Otherwise there are problems with a
+     shared library.
+. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
+     (a) It was defining its arguments as char * instead of void *.
+     (b) It was assuming that all moves were upwards in memory; this was true
+         a long time ago when I wrote it, but is no longer the case.
+     The emulated memove() is provided for those environments that have neither
+     memmove() nor bcopy(). I didn't think anyone used it these days, but that
+     is clearly not the case, as these two bugs were recently reported.
+. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
+     and Detrail to create the HTML documentation, the .txt form of the man
+     pages, and it removes trailing spaces from listed files. It also creates
+     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
+     case, it wraps all the #defines with #ifndefs. This script should be run
+     before "make dist".
+. Fixed two fairly obscure bugs concerned with quantified caseless matching
+     with Unicode property support.
+     (a) For a maximizing quantifier, if the two different cases of the
+         character were of different lengths in their UTF-8 codings (there are
+         some cases like this - I found 11), and the matching function had to
+         back up over a mixture of the two cases, it incorrectly assumed they
+         were both the same length.
+     (b) When PCRE was configured to use the heap rather than the stack for
+         recursion during matching, it was not correctly preserving the data for
+         the other case of a UTF-8 character when checking ahead for a match
+         while processing a minimizing repeat. If the check also involved
+         matching a wide character, but failed, corruption could cause an
+         erroneous result when trying to check for a repeat of the original
+         character.
+. Some tidying changes to the testing mechanism:
+     (a) The RunTest script now detects the internal link size and whether there
+         is UTF-8 and UCP support by running ./pcretest -C instead of relying on
+         values substituted by "configure". (The RunGrepTest script already did
+         this for UTF-8.) The configure.ac script no longer substitutes the
+         relevant variables.
+     (b) The debugging options /B and /D in pcretest show the compiled bytecode
+         with length and offset values. This means that the output is different
+         for different internal link sizes. Test 2 is skipped for link sizes
+         other than 2 because of this, bypassing the problem. Unfortunately,
+         there was also a test in test 3 (the locale tests) that used /B and
+         failed for link sizes other than 2. Rather than cut the whole test out,
+         I have added a new /Z option to pcretest that replaces the length and
+         offset values with spaces. This is now used to make test 3 independent
+         of link size. (Test 2 will be tidied up later.)
+. If erroroffset was passed as NULL to pcre_compile, it provoked a
+     segmentation fault instead of returning the appropriate error message.
+. In multiline mode when the newline sequence was set to "any", the pattern
+     ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
+     This doesn't seem right; it now treats the CRLF combination as the line
+     ending, and so does not match in that case. It's only a pattern such as ^$
+     that would hit this one: something like ^ABC$ would have failed after \r
+     and then tried again after \r\n.
+. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
+     in an attempt to make files that differ only in their line terminators
+     compare equal. This works on Linux.
+. Under certain error circumstances pcregrep might try to free random memory
+     as it exited. This is now fixed, thanks to valgrind.
+. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
+     "abc\r\n\r\n", it found an unwanted second match after the second \r. This
+     was because its rules for how to advance for /g after matching an empty
+     string at the end of a line did not allow for this case. They now check for
+     it specially.
+. pcretest is supposed to handle patterns and data of any length, by
+     extending its buffers when necessary. It was getting this wrong when the
+     buffer for a data line had to be extended.
+. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
+     CRLF as a newline sequence.
+. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
+     out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
+     I have nevertheless tidied it up.
+. Added some casts to kill warnings from HP-UX ia64 compiler.
+. Added a man page for pcre-config.
+ Version 7.0 19-Dec-06
+ ---------------------
+. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
+     moving to gcc 4.1.1.
+. The -S option for pcretest uses setrlimit(); I had omitted to #include
+     sys/time.h, which is documented as needed for this function. It doesn't
+     seem to matter on Linux, but it showed up on some releases of OS X.
+. It seems that there are systems where bytes whose values are greater than
+match isprint() in the "C" locale. The "C" locale should be the
+     default when a C program starts up. In most systems, only ASCII printing
+     characters match isprint(). This difference caused the output from pcretest
+     to vary, making some of the tests fail. I have changed pcretest so that:
+     (a) When it is outputting text in the compiled version of a pattern, bytes
+         other than 32-126 are always shown as hex escapes.
+     (b) When it is outputting text that is a matched part of a subject string,
+         it does the same, unless a different locale has been set for the match
+         (using the /L modifier). In this case, it uses isprint() to decide.
+. Fixed a major bug that caused incorrect computation of the amount of memory
+     required for a compiled pattern when options that changed within the
+     pattern affected the logic of the preliminary scan that determines the
+     length. The relevant options are -x, and -i in UTF-8 mode. The result was
+     that the computed length was too small. The symptoms of this bug were
+     either the PCRE error "internal error: code overflow" from pcre_compile(),
+     or a glibc crash with a message such as "pcretest: free(): invalid next
+     size (fast)". Examples of patterns that provoked this bug (shown in
+     pcretest format) are:
+       /(?-x: )/x
+       /(?x)(?-x: \s*#\s*)/
+       /((?i)[\x{c0}])/8
+       /(?i:[\x{c0}])/8
+     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
+     is now done differently.
+. Applied patches from Google to: (a) add a QuoteMeta function to the C++
+     wrapper classes; (b) implement a new function in the C++ scanner that is
+     more efficient than the old way of doing things because it avoids levels of
+     recursion in the regex matching; (c) add a paragraph to the documentation
+     for the FullMatch() function.
+. The escape sequence \n was being treated as whatever was defined as
+     "newline". Not only was this contrary to the documentation, which states
+     that \n is character 10 (hex 0A), but it also went horribly wrong when
+     "newline" was defined as CRLF. This has been fixed.
+. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
+     was being set to -1 for the "end of line" case (supposedly a value that no
+     character can have). Though this value is never used (the check for end of
+     line is "zero bytes in current character"), it caused compiler complaints.
+     I've changed it to 0xffffffff.
+. In pcre_version.c, the version string was being built by a sequence of
+     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
+     string (as it is for production releases) called a macro with an empty
+     argument. The C standard says the result of this is undefined. The gcc
+     compiler treats it as an empty string (which was what was wanted) but it is
+     reported that Visual C gives an error. The source has been hacked around to
+     avoid this problem.
+. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
+     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
+     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
+     of them did).
+. Originally, pcretest opened its input and output without "b"; then I was
+     told that "b" was needed in some environments, so it was added for release
+.0 to both the input and output. (It makes no difference on Unix-like
+     systems.) Later I was told that it is wrong for the input on Windows. I've
+     now abstracted the modes into two macros, to make it easier to fiddle with
+     them, and removed "b" from the input mode under Windows.
+. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
+. Added -help and --help to pcretest as an official way of being reminded
+     of the options.
+. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
+     and pcrecpp.cc because they annoy compilers at high warning levels.
+. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
+. Fixed an occurrence of == in configure.ac that should have been = (shell
+     scripts are not C programs :-) and which was not noticed because it works
+     on Linux.
+. pcretest is supposed to handle any length of pattern and data line (as one
+     line or as a continued sequence of lines) by extending its input buffer if
+     necessary. This feature was broken for very long pattern lines, leading to
+     a string of junk being passed to pcre_compile() if the pattern was longer
+     than about 50K.
+. I have done a major re-factoring of the way pcre_compile() computes the
+     amount of memory needed for a compiled pattern. Previously, there was code
+     that made a preliminary scan of the pattern in order to do this. That was
+     OK when PCRE was new, but as the facilities have expanded, it has become
+     harder and harder to keep it in step with the real compile phase, and there
+     have been a number of bugs (see for example, 4 above). I have now found a
+     cunning way of running the real compile function in a "fake" mode that
+     enables it to compute how much memory it would need, while actually only
+     ever using a few hundred bytes of working memory and without too many
+     tests of the mode. This should make future maintenance and development
+     easier. A side effect of this work is that the limit of 200 on the nesting
+     depth of parentheses has been removed (though this was never a serious
+     limitation, I suspect). However, there is a downside: pcre_compile() now
+     runs more slowly than before (30% or more, depending on the pattern). I
+     hope this isn't a big issue. There is no effect on runtime performance.
+. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
+     newline (only possible for the last line of a file) and it was a
+     pattern that set a locale (followed by /Lsomething), pcretest crashed.
+. Added additional timing features to pcretest. (1) The -tm option now times
+     matching only, not compiling. (2) Both -t and -tm can be followed, as a
+     separate command line item, by a number that specifies the number of
+     repeats to use when timing. The default is 50000; this gives better
+     precision, but takes uncomfortably long for very large patterns.
+. Extended pcre_study() to be more clever in cases where a branch of a
+     subpattern has no definite first character. For example, (a*|b*)[cd] would
+     previously give no result from pcre_study(). Now it recognizes that the
+     first character must be a, b, c, or d.
+. There was an incorrect error "recursive call could loop indefinitely" if
+     a subpattern (or the entire pattern) that was being tested for matching an
+     empty string contained only one non-empty item after a nested subpattern.
+     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
+     incorrectly, because the \d was being skipped in the check.
+. The pcretest program now has a new pattern option /B and a command line
+     option -b, which is equivalent to adding /B to every pattern. This causes
+     it to show the compiled bytecode, without the additional information that
+     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
+     is the same as /B/I).
+. A new optimization is now able automatically to treat some sequences such
+     as a*b as a*+b. More specifically, if something simple (such as a character
+     or a simple class like \d) has an unlimited quantifier, and is followed by
+     something that cannot possibly match the quantified thing, the quantifier
+     is automatically "possessified".
+. A recursive reference to a subpattern whose number was greater than 39
+     went wrong under certain circumstances in UTF-8 mode. This bug could also
+     have affected the operation of pcre_study().
+. Realized that a little bit of performance could be had by replacing
+     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
+. Timing data from pcretest is now shown to 4 decimal places instead of 3.
+. Possessive quantifiers such as a++ were previously implemented by turning
+     them into atomic groups such as ($>a+). Now they have their own opcodes,
+     which improves performance. This includes the automatically created ones
+     from 23 above.
+. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
+     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
+     the first matched character to be a colon. This applied both to named and
+     numbered groups.
+. The ucpinternal.h header file was missing its idempotency #ifdef.
+. I was sent a "project" file called libpcre.a.dev which I understand makes
+     building PCRE on Windows easier, so I have included it in the distribution.
+. There is now a check in pcretest against a ridiculously large number being
+     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
+     loop, the loop is abandoned.
+. Forward references to subpatterns in conditions such as (?(2)...) where
+     subpattern 2 is defined later cause pcre_compile() to search forwards in
+     the pattern for the relevant set of parentheses. This search went wrong
+     when there were unescaped parentheses in a character class, parentheses
+     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
+. "Subroutine" calls and backreferences were previously restricted to
+     referencing subpatterns earlier in the regex. This restriction has now
+     been removed.
+. Added a number of extra features that are going to be in Perl 5.10. On the
+     whole, these are just syntactic alternatives for features that PCRE had
+     previously implemented using the Python syntax or my own invention. The
+     other formats are all retained for compatibility.
+     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
+         as (?P<name>...). The new forms, as well as being in Perl 5.10, are
+         also .NET compatible.
+     (b) A recursion or subroutine call to a named group can now be defined as
+         (?&name) as well as (?P>name).
+     (c) A backreference to a named group can now be defined as \k<name> or
+         \k'name' as well as (?P=name). The new forms, as well as being in Perl
+.10, are also .NET compatible.
+     (d) A conditional reference to a named group can now use the syntax
+         (?(<name>) or (?('name') as well as (?(name).
+     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
+         groups (named and numbered) that are never evaluated inline, but can be
+         called as "subroutines" from elsewhere. In effect, the DEFINE condition
+         is always false. There may be only one alternative in such a group.
+     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
+         as the simple (?(R). The condition is true only if the most recent
+         recursion is that of the given number or name. It does not search out
+         through the entire recursion stack.
+     (g) The escape \gN or \g{N} has been added, where N is a positive or
+         negative number, specifying an absolute or relative reference.
+. Tidied to get rid of some further signed/unsigned compiler warnings and
+     some "unreachable code" warnings.
+. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
+     things, this adds five new scripts.
+. Perl ignores orphaned \E escapes completely. PCRE now does the same.
+     There were also incompatibilities regarding the handling of \Q..\E inside
+     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
+     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
+. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
+     matches an empty string, and forcibly breaks the loop. There were bugs in
+     this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
+     against  aaaa  the result was just "a" rather than "aaaa", for example. Two
+     separate and independent bugs (that affected different cases) have been
+     fixed.
+. Refactored the code to abolish the use of different opcodes for small
+     capturing bracket numbers. This is a tidy that I avoided doing when I
+     removed the limit on the number of capturing brackets for 3.5 back in 2001.
+     The new approach is not only tidier, it makes it possible to reduce the
+     memory needed to fix the previous bug (38).
+. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
+     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
+     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
+     mode.
+. Add \R to match any Unicode newline sequence, as suggested in the Unicode
+     report.
+. Applied patch, originally from Ari Pollak, modified by Google, to allow
+     copy construction and assignment in the C++ wrapper.
+. Updated pcregrep to support "--newline=any". In the process, I fixed a
+     couple of bugs that could have given wrong results in the "--newline=crlf"
+     case.
+. Added a number of casts and did some reorganization of signed/unsigned int
+     variables following suggestions from Dair Grant. Also renamed the variable
+     "this" as "item" because it is a C++ keyword.
+. Arranged for dftables to add
+       #include "pcre_internal.h"
+     to pcre_chartables.c because without it, gcc 4.x may remove the array
+     definition from the final binary if PCRE is built into a static library and
+     dead code stripping is activated.
+. For an unanchored pattern, if a match attempt fails at the start of a
+     newline sequence, and the newline setting is CRLF or ANY, and the next two
+     characters are CRLF, advance by two characters instead of one.
+ Version 6.7 04-Jul-06
+ ---------------------
+. In order to handle tests when input lines are enormously long, pcretest has
+     been re-factored so that it automatically extends its buffers when
+     necessary. The code is crude, but this _is_ just a test program. The
+     default size has been increased from 32K to 50K.
+. The code in pcre_study() was using the value of the re argument before
+     testing it for NULL. (Of course, in any sensible call of the function, it
+     won't be NULL.)
+. The memmove() emulation function in pcre_internal.h, which is used on
+     systems that lack both memmove() and bcopy() - that is, hardly ever -
+     was missing a "static" storage class specifier.
+. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
+     containing an extended class (one that cannot be represented by a bitmap
+     because it contains high-valued characters or Unicode property items, e.g.
+     [\pZ]). Almost always one would set UTF-8 mode when processing such a
+     pattern, but PCRE should not loop if you do not (it no longer does).
+     [Detail: two cases were found: (a) a repeated subpattern containing an
+     extended class; (b) a recursive reference to a subpattern that followed a
+     previous extended class. It wasn't skipping over the extended class
+     correctly when UTF-8 mode was not set.]
+. A negated single-character class was not being recognized as fixed-length
+     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
+     compile error "lookbehind assertion is not fixed length".
+. The RunPerlTest auxiliary script was showing an unexpected difference
+     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
+     write a Perl script that can interpret lines of an input file either as
+     byte characters or as UTF-8, which is what "perltest" was being required to
+     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
+     can't do is switch easily at run time between having the "use utf8;" pragma
+     or not. In the end, I fudged it by using the RunPerlTest script to insert
+     "use utf8;" explicitly for the UTF-8 tests.
+. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
+     the end of the subject string, contrary to the documentation and to what
+     Perl does. This was true of both matching functions. Now it matches only at
+     the start of the subject and immediately after *internal* newlines.
+. A call of pcre_fullinfo() from pcretest to get the option bits was passing
+     a pointer to an int instead of a pointer to an unsigned long int. This
+     caused problems on 64-bit systems.
+. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
+     instance of the 'standard' template library not being so standard".
+. There was no check on the number of named subpatterns nor the maximum
+     length of a subpattern name. The product of these values is used to compute
+     the size of the memory block for a compiled pattern. By supplying a very
+     long subpattern name and a large number of named subpatterns, the size
+     computation could be caused to overflow. This is now prevented by limiting
+     the length of names to 32 characters, and the number of named subpatterns
+     to 10,000.
+. Subpatterns that are repeated with specific counts have to be replicated in
+     the compiled pattern. The size of memory for this was computed from the
+     length of the subpattern and the repeat count. The latter is limited to
+, but there was no limit on the former, meaning that integer overflow
+     could in principle occur. The compiled length of a repeated subpattern is
+     now limited to 30,000 bytes in order to prevent this.
+. Added the optional facility to have named substrings with the same name.
+. Added the ability to use a named substring as a condition, using the
+     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
+     are numbers (not recommended). Forward references are permitted.
+. Added forward references in named backreferences (if you see what I mean).
+. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
+     pattern could run off the end of the subject. For example, the pattern
+     "(?s)(.{1,5})"8 did this with the subject "ab".
+. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
+     PCRE_CASELESS was set when matching characters that were quantified with ?
+     or *.
+. A character class other than a single negated character that had a minimum
+     but no maximum quantifier - for example [ab]{6,} - was not handled
+     correctly by pce_dfa_exec(). It would match only one character.
+. A valid (though odd) pattern that looked like a POSIX character
+     class but used an invalid character after [ (for example [[,abc,]]) caused
+     pcre_compile() to give the error "Failed: internal error: code overflow" or
+     in some cases to crash with a glibc free() error. This could even happen if
+     the pattern terminated after [[ but there just happened to be a sequence of
+     letters, a binary zero, and a closing ] in the memory that followed.
+. Perl's treatment of octal escapes in the range \400 to \777 has changed
+     over the years. Originally (before any Unicode support), just the bottom 8
+     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
+     output from "man perlunicode" includes this:
+       The regular expression compiler produces polymorphic opcodes.  That
+       is, the pattern adapts to the data and automatically switches to
+       the Unicode character scheme when presented with Unicode data--or
+       instead uses a traditional byte scheme when presented with byte
+       data.
+     Sadly, a wide octal escape does not cause a switch, and in a string with
+     no other multibyte characters, these octal escapes are treated as before.
+     Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
+     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
+     Unicode string.
+     I have not perpetrated such confusion in PCRE. Up till now, it took just
+     the bottom 8 bits, as in old Perl. I have now made octal escapes with
+     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
+     translate to the appropriate multibyte character.
+. Applied some refactoring to reduce the number of warnings from Microsoft
+     and Borland compilers. This has included removing the fudge introduced
+     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
+     a warning about an unused variable.
+. PCRE has not included VT (character 0x0b) in the set of whitespace
+     characters since release 4.0, because Perl (from release 5.004) does not.
+     [Or at least, is documented not to: some releases seem to be in conflict
+     with the documentation.] However, when a pattern was studied with
+     pcre_study() and all its branches started with \s, PCRE still included VT
+     as a possible starting character. Of course, this did no harm; it just
+     caused an unnecessary match attempt.
+. Removed a now-redundant internal flag bit that recorded the fact that case
+     dependency changed within the pattern. This was once needed for "required
+     byte" processing, but is no longer used. This recovers a now-scarce options
+     bit. Also moved the least significant internal flag bit to the most-
+     significant bit of the word, which was not previously used (hangover from
+     the days when it was an int rather than a uint) to free up another bit for
+     the future.
+. Added support for CRLF line endings as well as CR and LF. As well as the
+     default being selectable at build time, it can now be changed at runtime
+     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
+     specify that it is scanning data with non-default line endings.
+. Changed the definition of CXXLINK to make it agree with the definition of
+     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
+. Applied Ian Taylor's patches to avoid using another stack frame for tail
+     recursions. This makes a big different to stack usage for some patterns.
+. If a subpattern containing a named recursion or subroutine reference such
+     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
+     the space required for the compiled pattern went wrong and gave too small a
+     value. Depending on the environment, this could lead to "Failed: internal
+     error: code overflow at offset 49" or "glibc detected double free or
+     corruption" errors.
+. Applied patches from Google (a) to support the new newline modes and (b) to
+     advance over multibyte UTF-8 characters in GlobalReplace.
+. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
+     difference for some implementation of PCRE in some Windows version.
+. Added some extra testing facilities to pcretest:
+     \q<number>   in a data line sets the "match limit" value
+     \Q<number>   in a data line sets the "match recursion limt" value
+     -S <number>  sets the stack size, where <number> is in megabytes
+     The -S option isn't available for Windows.
+ Version 6.6 06-Feb-06
+ ---------------------
+. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
+     in pcreposix.h. I have copied the definition from pcre.h.
+. Change 25 for 6.5 broke compilation in a build directory out-of-tree
+     because pcre.h is no longer a built file.
+. Added Jeff Friedl's additional debugging patches to pcregrep. These are
+     not normally included in the compiled code.
+ Version 6.5 01-Feb-06
+ ---------------------
+. When using the partial match feature with pcre_dfa_exec(), it was not
+     anchoring the second and subsequent partial matches at the new starting
+     point. This could lead to incorrect results. For example, with the pattern
+     /1234/, partially matching against "123" and then "a4" gave a match.
+. Changes to pcregrep:
+     (a) All non-match returns from pcre_exec() were being treated as failures
+         to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
+         error message is output. Some extra information is given for the
+         PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
+         probably the only errors that are likely to be caused by users (by
+         specifying a regex that has nested indefinite repeats, for instance).
+         If there are more than 20 of these errors, pcregrep is abandoned.
+     (b) A binary zero was treated as data while matching, but terminated the
+         output line if it was written out. This has been fixed: binary zeroes
+         are now no different to any other data bytes.
+     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
+         used to set a locale for matching. The --locale=xxxx long option has
+         been added (no short equivalent) to specify a locale explicitly on the
+         pcregrep command, overriding the environment variables.
+     (d) When -B was used with -n, some line numbers in the output were one less
+         than they should have been.
+     (e) Added the -o (--only-matching) option.
+     (f) If -A or -C was used with -c (count only), some lines of context were
+         accidentally printed for the final match.
+     (g) Added the -H (--with-filename) option.
+     (h) The combination of options -rh failed to suppress file names for files
+         that were found from directory arguments.
+     (i) Added the -D (--devices) and -d (--directories) options.
+     (j) Added the -F (--fixed-strings) option.
+     (k) Allow "-" to be used as a file name for -f as well as for a data file.
+     (l) Added the --colo(u)r option.
+     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
+         is not present by default.
+. A nasty bug was discovered in the handling of recursive patterns, that is,
+     items such as (?R) or (?1), when the recursion could match a number of
+     alternatives. If it matched one of the alternatives, but subsequently,
+     outside the recursion, there was a failure, the code tried to back up into
+     the recursion. However, because of the way PCRE is implemented, this is not
+     possible, and the result was an incorrect result from the match.
+     In order to prevent this happening, the specification of recursion has
+     been changed so that all such subpatterns are automatically treated as
+     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
+. I had overlooked the fact that, in some locales, there are characters for
+     which isalpha() is true but neither isupper() nor islower() are true. In
+     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
+     and ordfeminine) are like this. This affected the treatment of \w and \W
+     when they appeared in character classes, but not when they appeared outside
+     a character class. The bit map for "word" characters is now created
+     separately from the results of isalnum() instead of just taking it from the
+     upper, lower, and digit maps. (Plus the underscore character, of course.)
+. The above bug also affected the handling of POSIX character classes such as
+     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
+     permanent tables. Instead, the bit maps for such a class were previously
+     created as the appropriate unions of the upper, lower, and digit bitmaps.
+     Now they are created by subtraction from the [[:word:]] class, which has
+     its own bitmap.
+. The [[:blank:]] character class matches horizontal, but not vertical space.
+     It is created by subtracting the vertical space characters (\x09, \x0a,
+     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
+     subtraction was done in the overall bitmap for a character class, meaning
+     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
+     be recognized. This bug has been fixed.
+. Patches from the folks at Google:
+       (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
+       real life, but is still worth protecting against".
+       (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
+       regular expressions".
+       (c) pcre_scanner.cc: avoid use of std::count() because not all systems
+       have it.
+       (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
+       "configure" and the latter not, in order to fix a problem somebody had
+       with compiling the Arg class on HP-UX.
+       (e) Improve the error-handling of the C++ wrapper a little bit.
+       (f) New tests for checking recursion limiting.
+. The pcre_memmove() function, which is used only if the environment does not
+     have a standard memmove() function (and is therefore rarely compiled),
+     contained two bugs: (a) use of int instead of size_t, and (b) it was not
+     returning a result (though PCRE never actually uses the result).
+. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
+     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
+     returned instead of calling malloc() with an overflowing number that would
+     most likely cause subsequent chaos.
+. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
+. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
+     with this option is matched, the nmatch and pmatch options of regexec() are
+     ignored.
+. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
+     provided in case anyone wants to the the POSIX interface with UTF-8
+     strings.
+. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
+     C++ linking (needed for some HP-UX environments).
+. Avoid compiler warnings in get_ucpname() when compiled without UCP support
+     (unused parameter) and in the pcre_printint() function (omitted "default"
+     switch label when the default is to do nothing).
+. Added some code to make it possible, when PCRE is compiled as a C++
+     library, to replace subject pointers for pcre_exec() with a smart pointer
+     class, thus making it possible to process discontinuous strings.
+. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
+     much the same function. They were added by different people who were trying
+     to make PCRE easy to compile on non-Unix systems. It has been suggested
+     that PCRE_EXPORT be abolished now that there is more automatic apparatus
+     for compiling on Windows systems. I have therefore replac