gnal handler is called if
they were blocked before by C<POSIX::sigprocmask> [perl #82040].

=item *

A signal handler called within a signal handler could cause leaks or
double-frees.  Now fixed [perl #76248].

=back

=head2 Miscellaneous Memory Leaks

=over

=item *

Several memory leaks when loading XS modules were fixed (5.12.2).

=item *

L<substr()|perlfunc/"substr EXPR,OFFSET,LENGTH,REPLACEMENT">,
L<pos()|perlfunc/"index STR,SUBSTR,POSITION">, L<keys()|perlfunc/"keys HASH">,
and L<vec()|perlfunc/"vec EXPR,OFFSET,BITS"> could, when used in combination
with lvalues, result in leaking the scalar value they operate on, and cause its
destruction to happen too late.  This has now been fixed.

=item *

The postincrement and postdecrement operators, C<++> and C<-->, used to cause
leaks when used on references.  This has now been fixed.

=item *

Nested C<map> and C<grep> blocks no longer leak memory when processing
large lists [perl #48004].

=item *

C<use I<VERSION>> and C<no I<VERSION>> no longer leak memory [perl #78436]
[perl #69050].

=item *

C<.=> followed by C<< <> >> or C<readline> would leak memory if C<$/>
contained characters beyond the octet range and the scalar assigned to
happened to be encoded as UTF8 internally [perl #72246].

=item *

C<eval 'BEGIN{die}'> no longer leaks memory on non-threaded builds.

=back

=head2 Memory Corruption and Crashes

=over

=item *

glob() no longer crashes when C<%File::Glob::> is empty and
C<CORE::GLOBAL::glob> isn't present [perl #75464] (5.12.2).

=item *

readline() has been fixed when interrupted by signals so it no longer
returns the "same thing" as before or random memory.

=item *

When assigning a list with duplicated keys to a hash, the assignment used to
return garbage and/or freed values:

    @a = %h = (list with some duplicate keys);

This has now been fixed [perl #31865].

=item *

The mechanism for freeing objects in globs used to leave dangling
pointers to freed SVs, meaning Perl users could see corrupted state
during destruction.

Perl now frees only the affected slots of the GV, rather than freeing
the GV itself.  This makes sure that there are no dangling refs or
corrupted state during destruction.

=item *

The interpreter no longer crashes when freeing deeply-nested arrays of
arrays.  Hashes have not been fixed yet [perl #44225].

=item *

Concatenating long strings under C<use encoding> no longer causes Perl to
crash [perl #78674].

=item *

Calling C<< ->import >> on a class lacking an import method could corrupt
the stack, resulting in strange behaviour.  For instance,

  push @a, "foo", $b = bar->import;

would assign "foo" to C<$b> [perl #63790].

=item *

The C<recv> function could crash when called with the MSG_TRUNC flag
[perl #75082].

=item *

C<formline> no longer crashes when passed a tainted format picture.  It also
taints C<$^A> now if its arguments are tainted [perl #79138].

=item *

A bug in how we process filetest operations could cause a segfault.
Filetests don't always expect an op on the stack, so we now use
TOPs only if we're sure that we're not C<stat>ing the C<_> filehandle.
This is indicated by C<OPf_KIDS> (as checked in ck_ftst) [perl #74542]
(5.12.1).

=item *

unpack() now handles scalar context correctly for C<%32H> and C<%32u>,
fixing a potential crash.  split() would crash because the third item
on the stack wasn't the regular expression it expected.  C<unpack("%2H",
...)> would return both the unpacked result and the checksum on the stack,
as would C<unpack("%2u", ...)> [perl #73814] (5.12.2).

=back

=head2 Fixes to Various Perl Operators

=over

=item *

The C<&>, C<|>, and C<^> bitwise operators no longer coerce read-only arguments
[perl #20661].

=item *

Stringifying a scalar containing "-0.0" no longer has the effect of turning
false into true [perl #45133].

=item *

Some numeric operators were converting integers to floating point,
resulting in loss of precision on 64-bit platforms [perl #77456].

=item *

sprintf() was ignoring locales when called with constant arguments
[perl #78632].

=item *

Combining the vector (C<%v>) flag and dynamic precision would
cause C<sprintf> to confuse the order of its arguments, making it 
treat the string as the precision and vice-versa [perl #83194].

=back

=head2 Bugs Relating to the C API

=over

=item *

The C-level C<lex_stuff_pvn> function would sometimes cause a spurious
syntax error on the last line of the file if it lacked a final semicolon
[perl #74006] (5.12.1).

=item *

The C<eval_sv> and C<eval_pv> C functions now set C<$@> correctly when
there is a syntax error and no C<G_KEEPERR> flag, and never set it if the
C<G_KEEPERR> flag is present [perl #3719].

=item *

The XS multicall API no longer causes subroutines to lose reference counts
if called via the multicall interface from within those very subroutines.
This affects modules like L<List::Util>.  Calling one of its functions with an
active subroutine as the first argument could cause a crash [perl #78070].

=item *

The C<SvPVbyte> function available to XS modules now calls magic before
downgrading the SV, to avoid warnings about wide characters [perl #72398].

=item *

The ref types in the typemap for XS bindings now support magical variables
[perl #72684].

=item *

C<sv_catsv_flags> no longer calls C<mg_get> on its second argument (the
source string) if the flags passed to it do not include SV_GMAGIC.  So it
now matches the documentation.

=item *

C<my_strftime> no longer leaks memory.  This fixes a memory leak in
C<POSIX::strftime> [perl #73520].

=item *

F<XSUB.h> now correctly redefines fgets under PERL_IMPLICIT_SYS [perl #55049]
(5.12.1).

=item *

XS code using fputc() or fputs() on Windows could cause an error
due to their arguments being swapped [perl #72704] (5.12.1).

=item *

A possible segfault in the C<T_PTROBJ> default typemap has been fixed
(5.12.2).

=item *

A bug that could cause "Unknown error" messages when
C<call_sv(code, G_EVAL)> is called from an XS destructor has been fixed
(5.12.2).

=back

=head1 Known Problems

This is a list of significant unresolved issues which are regressions
from earlier versions of Perl or which affect widely-used CPAN modules.

=over 4

=item *

C<List::Util::first> misbehaves in the presence of a lexical C<$_>
(typically introduced by C<my $_> or implicitly by C<given>).  The variable
that gets set for each iteration is the package variable C<$_>, not the
lexical C<$_>.

A similar issue may occur in other modules that provide functions which
take a block as their first argument, like

    foo { ... $_ ...} list

See also: L<https://github.com/Perl/perl5/issues/9798>

=item *

readline() returns an empty string instead of a cached previous value
when it is interrupted by a signal

=item *

The changes in prototype handling break L<Switch>.  A patch has been sent
upstream and will hopefully appear on CPAN soon.

=item *

The upgrade to F<ExtUtils-MakeMaker-6.57_05> has caused
some tests in the F<Module-Install> distribution on CPAN to
fail. (Specifically, F<02_mymeta.t> tests 5 and 21; F<18_all_from.t>
tests 6 and 15; F<19_authors.t> tests 5, 13, 21, and 29; and
F<20_authors_with_special_characters.t> tests 6, 15, and 23 in version
1.00 of that distribution now fail.)

=item *

On VMS, C<Time::HiRes> tests will fail due to a bug in the CRTL's
implementation of C<setitimer>: previous timer values would be cleared
if a timer expired but not if the timer was reset before expiring.  HP
OpenVMS Engineering have corrected the problem and will release a patch
in due course (Quix case # QXCM1001115136).

=item *

On VMS, there were a handful of C<Module::Build> test failures we didn't
get to before the release; please watch CPAN for updates.

=back

=head1 Errata

=head2 keys(), values(), and each() work on arrays

You can now use the keys(), values(), and each() builtins on arrays;
previously you could use them only on hashes.  See L<perlfunc> for details.
This is actually a change introduced in perl 5.12.0, but it was missed from
that release's L<perl5120delta>.

=head2 split() and C<@_>

split() no longer modifies C<@_> when called in scalar or void context.
In void context it now produces a "Useless use of split" warning.
This was also a perl 5.12.0 change that missed the perldelta.

=head1 Obituary

Randy Kobes, creator of http://kobesearch.cpan.org/ and
contributor/maintainer to several core Perl toolchain modules, passed
away on September 18, 2010 after a battle with lung cancer.  The community
was richer for his involvement.  He will be missed.

=head1 Acknowledgements

Perl 5.14.0 represents one year of development since
Perl 5.12.0 and contains nearly 550,000 lines of changes across nearly
3,000 files from 150 authors and committers.

Perl continues to flourish into its third decade thanks to a vibrant
community of users and developers.  The following people are known to
have contributed the improvements that became Perl 5.14.0:

Aaron Crane, Abhijit Menon-Sen, Abigail, Ævar Arnfjörð Bjarmason,
Alastair Douglas, Alexander Alekseev, Alexander Hartmaier, Alexandr
Ciornii, Alex Davies, Alex Vandiver, Ali Polatel, Allen Smith, Andreas
König, Andrew Rodland, Andy Armstrong, Andy Dougherty, Aristotle
Pagaltzis, Arkturuz, Arvan, A. Sinan Unur, Ben Morrow, Bo Lindbergh,
Boris Ratner, Brad Gilbert, Bram, brian d foy, Brian Phillips, Casey
West, Charles Bailey, Chas. Owens, Chip Salzenberg, Chris 'BinGOs'
Williams, chromatic, Craig A. Berry, Curtis Jewell, Dagfinn Ilmari
Mannsåker, Dan Dascalescu, Dave Rolsky, David Caldwell, David Cantrell,
David Golden, David Leadbeater, David Mitchell, David Wheeler, Eric
Brine, Father Chrysostomos, Fingle Nark, Florian Ragwitz, Frank Wiegand,
Franz Fasching, Gene Sullivan, George Greer, Gerard Goossen, Gisle Aas,
Goro Fuji, Grant McLean, gregor herrmann, H.Merijn Brand, Hongwen Qiu,
Hugo van der Sanden, Ian Goodacre, James E Keenan, James Mastros, Jan
Dubois, Jay Hannah, Jerry D. Hedden, Jesse Vincent, Jim Cromie, Jirka
Hruška, John Peacock, Joshua ben Jore, Joshua Pritikin, Karl Williamson,
Kevin Ryde, kmx, Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Larwan Berke, Leon Brocard, Leon
Timmermans, Lubomir Rintel, Lukas Mai, Maik Hentsche, Marty Pauley,
Marvin Humphrey, Matt Johnson, Matt S Trout, Max Maischein, Michael
Breen, Michael Fig, Michael G Schwern, Michael Parker, Michael Stevens,
Michael Witten, Mike Kelly, Moritz Lenz, Nicholas Clark, Nick Cleaton,
Nick Johnston, Nicolas Kaiser, Niko Tyni, Noirin Shirley, Nuno Carvalho,
Paul Evans, Paul Green, Paul Johnson, Paul Marquess, Peter J. Holzer,
Peter John Acklam, Peter Martini, Philippe Bruhat (BooK), Piotr Fusik,
Rafael Garcia-Suarez, Rainer Tammer, Reini Urban, Renee Baecker, Ricardo
Signes, Richard Möhn, Richard Soderberg, Rob Hoelz, Robin Barker, Ruslan
Zakirov, Salvador Fandiño, Salvador Ortiz Garcia, Shlomi Fish, Sinan
Unur, Sisyphus, Slaven Rezic, Steffen Müller, Steve Hay, Steven
Schubiger, Steve Peters, Sullivan Beck, Tatsuhiko Miyagawa, Tim Bunce,
Todd Rinaldo, Tom Christiansen, Tom Hukins, Tony Cook, Tye McQueen,
Vadim Konovalov, Vernon Lyon, Vincent Pit, Walt Mankowski, Wolfram
Humann, Yves Orton, Zefram, and Zsbán Ambrus.

This is woefully incomplete as it's automatically generated from version
control history.  In particular, it doesn't include the names of the
(very much appreciated) contributors who reported issues in previous
versions of Perl that helped make Perl 5.14.0 better. For a more complete
list of all of Perl's historical contributors, please see the C<AUTHORS>
file in the Perl 5.14.0 distribution.

Many of the changes included in this version originated in the CPAN
modules included in Perl's core. We're grateful to the entire CPAN
community for helping Perl to flourish.

=head1 Reporting Bugs

If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the Perl
bug database at http://rt.perl.org/perlbug/ .  There may also be
information at http://www.perl.org/ , the Perl Home Page.

If you believe you have an unreported bug, please run the L<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 C<perl -V>, will be sent off to perlbug@perl.org 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 perl5-security-report@perl.org.  This points to a closed subscription
unarchived mailing list, which includes all the core committers, who are 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 use this address for
security issues in the Perl core I<only>, not for modules independently
distributed on CPAN.

=head1 SEE ALSO

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

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=cut