This document describes differences between the 5.13.2 release and the
       5.13.1 release.

       If you are upgrading from an earlier release such as 5.10, first read
       perl5120delta, which describes differences between 5.10 and 5.12.

Incompatible Changes
   localised tied scalars are tied again.
       The change in behaviour in 5.13.1 of localising tied scalar values has
       been reverted to the existing 5.12.0 and earlier behaviour (the change
       for arrays and hashes remains).

   Naming fixes in Policy_sh.SH may invalidate
       Several long-standing typos and naming confusions in Policy_sh.SH have
       been fixed, standardizing on the variable names used in

       This will change the behavior of if you happen to have been
       accidentally relying on the incorrect behavior. We'd
       appreciate feedback from anyone using to be sure nothing is
       broken by this change (c1bd23).

   Stashes are now always defined
       "defined %Foo::" now always returns true, even when no symbols have yet
       been defined in that package.

       This is a side effect of removing a special case kludge in the
       tokeniser, added for 5.10.0, to hide side effects of changes to the
       internal storage of hashes that to drastically reduce their memory
       usage overhead.

       Calling defined on a stash has been deprecated since 5.6.0, warned on
       lexicals since 5.6.0, and has warned for stashes (and other package
       variables) since 5.12.0. "defined %hash" has always exposed an
       implementation detail - emptying a hash by deleting all entries from it
       does not make "defined %hash" false, hence "defined %hash" is not valid
       code to determine whether an arbitrary hash is empty. Instead, use the
       behaviour that an empty %hash always returns false in a scalar context.

Core Enhancements
   Non-destructive substitution
       The substitution operator now supports a "/r" option that copies the
       input variable, carries out the substitution on the copy and returns
       the result.  The original remains unmodified.

         my $old = 'cat';
         my $new = $old =~ s/cat/dog/r;
         # $old is 'cat' and $new is 'dog'

       This is particularly useful with "map".  See perlop for more examples
       (4f4d75, 000c65).

   package block syntax

   perl -h no longer recommends -w
       perl -h used to mark the -w option as recommended; since this option is
       far less useful than it used to be due to lexical 'use warnings' and
       since perl -h is primary a list and brief explanation of the command
       line switches, the recommendation has now been removed (60eaec).

Modules and Pragmata
   Updated Modules
       Locale-Codes 3.13

       Locale::Country, Locale::Language and Locale::Currency were updated
       from 3.12 to 3.13 of the Locale-Codes distribution to include locale
       code changes (e1137b).

       Thread-Semaphore 2.11

       Added new methods ->down_nb() and ->down_force() at the suggestion of
       Rick Garlick.

       Refactored methods to skip argument validation when no argument is

       (04febe, f06daa) 1.94_57

       o   release 1.94_57

       o   bugfix: treat modules correctly that are deprecated in perl 5.12.

       o   bugfix: RT #57482 and #57788 revealed that configure_requires
           implicitly assumed build_requires instead of normal requires.
           (Reported by Andrew Whatson and Father Chrysostomos respectively)

       o   testfix: solaris should run the tests without expect because
           (some?)  solaris have a broken expect

       o   testfix: run tests with cache_metadata off to prevent spill over
           effects from previous test runs


       Hash::Util warning fix

       Hash::Util now enables "no warnings 'uninitialized'" to suppress
       spurious warnings from undefined hash values (RT #74280).

       B::Deparse now handles 'no VERSION'

       The 'no 5.13.2' or similar form is now correctly handled by B::Deparse.

       IO::Socket doc additions

       Multiple POD spelling fixes.

       Fixes were made to VMS::DCLsym, mro, Search::Dist, B::t::OptreeCheck
       and UNIVERSAL.

Changes to Existing Documentation
   Replace wrong tr/// table in perlebcdic.pod
       perlebcdic.pod contains a helpful table to use in tr/// to convert
       between EBCDIC and Latin1/ASCII.  Unfortunately, the table was the
       inverse of the one it describes, though the code that used the table
       worked correctly for the specific example given.

       The table has been changed to its inverse, and the sample code changed
       to correspond, as this is easier for the person trying to follow the
       instructions since deriving the old table is somewhat more complicated.

       The table has also been changed to hex from octal, as that is more the
       norm these days, and the recipes in the pod altered to print out
       leading zeros to make all the values the same length, as the table that
       they can generate has them (5f26d5).

   Document tricks for user-defined casing
       perlunicode.pod now contains an explanation of how to override, mangle
       and otherwise tweak the way perl handles upper, lower and other case
       conversions on unicode data, and how to provide scoped changes to alter
       one's own code's behaviour without stomping on anybody else (71648f).

   Document $# and $* as removed and clarify $#array usage
       $# and $* were both disabled as of perl5 version 10; this release adds
       documentation to that effect, a description of the results of
       continuing to try and use them, and a note explaining that $# can also
       function as a sigil in the $#array form (7f315d2).

   INSTALL explicitly states the requirement for C89
       This was already true but it's now Officially Stated For The Record

   No longer advertise Math::TrulyRandom
       This module hasn't been updated since 1996 so we can't recommend it any
       more (83918a).

   perlfaq synchronised to upstream
       The FAQ has been updated to commit
       37550b8f812e591bcd0dd869d61677dac5bda92c from the perlfaq repository at

Performance Enhancements
       Only allocate entries for @_ on demand - this not only saves memory per
       subroutine defined but should hopefully improve COW behaviour (77bac2).

   Multiple small improvements to threads
       The internal structures of threading now make fewer API calls and fewer
       allocations, resulting in noticeably smaller object code. Additionally,
       many thread context checks have been deferred so that they're only done
       The order of structure elements in SV bodies has changed. Effectively,
       the NV slot has swapped location with STASH and MAGIC. As all access to
       SV members is via macros, this should be completely transparent. This
       change allows the space saving for PVHVs documented above, and may
       reduce the memory allocation needed for PVIVs on some architectures.

   Optimisation of regexp engine string comparison work
       The foldEQ_utf8 API function for case-insensitive comparison of strings
       (which is used heavily by the regexp engine) was substantially
       refactored and optimised - and its documentation much improved as a
       free bonus gift (8b3587, e6226b).

   Memory consumption improvements to Exporter
       The @EXPORT_FAIL AV is no longer created unless required, hence neither
       is the typeglob backing it - this saves about 200 bytes per Exporter
       using package that doesn't use this functionality.

Installation and Configuration Improvements
   Compilation improvements
       Fix CCINCDIR and CCLIBDIR for mingw64 cross compiler to correctly be
       under $(CCHOME)\mingw\include and \lib rather than immediately below

       This means the 'incpath', 'libpth', 'ldflags', 'lddlflags' and
       'ldflags_nolargefiles' values in and are now
       set correctly (23ae7f).

Selected Bug Fixes
       o   Timely cleanup of SVs that are cloned into a new thread but then
           discovered to be orphaned (i.e. their owners are -not- cloned)

       o   Don't accidentally clone lexicals in scope within active stack
           frames in the parent when creating a child thread (RT #73086)

       o   Avoid loading when 'no 5.13.2;' or similar is
           encountered (faee19).

       o   Trap invalid use of SvIVX on SVt_REGEXP when assertions are on

       o   Don't stamp on $DB::single, $DB::trace and $DB::signal if they
           already have values when $^P is assigned to (RT #72422) (4c0f30).

       o   chop now correctly handles perl's extended UTF-8 (RT #73246)

       o   Defer signal handling when shared SV locks are held to avoid
           deadlocks (RT #74868) (65c742).

       o   glob() no longer crashes when %File::Glob:: is empty and
           CORE::GLOBAL::glob isn't present (4984aa).

           calling FETCH correctly (RT #8438) (7c7501)

Changed Internals
       o   The implementation of sv_dup_inc() has changed from a macro to a

       o   The "find_rundefsvoffset" function has been deprecated. It appeared
           that its design was insufficient to reliably get the lexical $_ at

           Use the new "find_rundefsv" function or the "UNDERBAR" macro
           instead.  They directly return the right SV representing $_,
           whether it's lexical or dynamic (789bd8 .. 03d5bc).

       o   The following new functions or macros have been added to the public
           API: "SvNV_nomg",  "sv_2nv_flags", "find_rundefsv".

       o   The "UNDERBAR" macro now calls "find_rundefsv". "dUNDERBAR" is now
           a noop but should still be used to ensure past and future

       o   The ibcmp_* functions have been renamed and are now called foldEQ,
           foldEQ_locale and foldEQ_utf8 (e6226b).

       The following items are now deprecated.

       o   Omitting a space between a regex pattern or pattern modifiers and
           the following word is deprecated.  For example, "m/foo/sand $bar"
           will still be parsed as "m/foo/s and $bar" but will issue a

Platform Specific Notes
   Recent OpenBSDs now use perl's malloc
       OpenBSD > 3.7 has a new malloc implementation which is mmap based and
       as such can release memory back to the OS; however for perl using this
       malloc causes a substantial slowdown so we now default to using perl's
       malloc instead (RT #75742) (9b58b5).

       Perl 5.13.2 represents thirty days of development since Perl 5.13.1
       (and two days of waiting around while the release manager remembered
       where he left his brain) and contains 3685 lines of changes across 194
       files from 30 authors and committers.

       Thank you to the following for contributing to this release:

       Abigail, Andreas J. Koenig, Chas. Owens, Chris 'BinGOs' Williams, Craig
       A. Berry, David Caldwell, David Golden, David Mitchell, Father
       Chrysostomos, George Greer, H.Merijn Brand, Jerry D. Hedden, Karl
       Williamson, Maik Hentsche, Matt S Trout, Nicholas Clark, Rafael Garcia-
       Suarez, Ricardo Signes, Salvador Fandino, Salvador Ortiz Garcia, Shlomi
       Fish, Sinan Unur, Sisyphus, Slaven Rezic, Sullivan Beck, Tony Cook,
       Vincent Pit, Zefram, brian d foy, var Arnfjoer` Bjarmason
       If you believe you have an unreported bug, please run the perlbug
       program included with your release.  Be sure to trim your bug down to a
       tiny but sufficient test case.  Your bug report, along with the output
       of "perl -V", will be sent off to to be analysed by
       the Perl porting team.

       If the bug you are reporting has security implications, which make it
       inappropriate to send to a publicly archived mailing list, then please
       send it to This points to a closed
       subscription unarchived mailing list, which includes all the core
       committers, who be able to help assess the impact of issues, figure out
       a resolution, and help co-ordinate the release of patches to mitigate
       or fix the problem across all platforms on which Perl is supported.
       Please only use this address for security issues in the Perl core, not
       for modules independently distributed on CPAN.

       The Changes file for an explanation of how to view exhaustive details
       on what changed.

       The INSTALL file for how to build Perl.

       The README file for general stuff.

       The Artistic and Copying files for copyright information.

perl v5.14.2                      2011-09-26                  PERL5132DELTA(1)
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