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✏️ Editing: perl5161delta.pod

=encoding utf8

=head1 NAME

perl5161delta - what is new for perl v5.16.1

=head1 DESCRIPTION

This document describes differences between the 5.16.0 release and
the 5.16.1 release.

If you are upgrading from an earlier release such as 5.14.0, first read
L<perl5160delta>, which describes differences between 5.14.0 and
5.16.0.

=head1 Security

=head2 an off-by-two error in Scalar-List-Util has been fixed

The bugfix was in Scalar-List-Util 1.23_04, and perl 5.16.1 includes
Scalar-List-Util 1.25.

=head1 Incompatible Changes

There are no changes intentionally incompatible with 5.16.0 If any
exist, they are bugs, and we request that you submit a report.  See
L</Reporting Bugs> below.

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<Scalar::Util> and L<List::Util> have been upgraded from version 1.23 to
version 1.25.

=item *

L<B::Deparse> has been updated from version 1.14 to 1.14_01.  An
"uninitialized" warning emitted by B::Deparse has been squashed
[perl #113464].

=back

=head1 Configuration and Compilation

=over

=item *

Building perl with some Windows compilers used to fail due to a problem
with miniperl's C<glob> operator (which uses the C<perlglob> program)
deleting the PATH environment variable [perl #113798].

=back

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item VMS

All C header files from the top-level directory of the distribution are now
installed on VMS, providing consistency with a long-standing practice on other
platforms. Previously only a subset were installed, which broke non-core extension
builds for extensions that depended on the missing include files.

=back

=head1 Selected Bug Fixes

=over 4

=item *

A regression introduced in Perl v5.16.0 involving
C<tr/I<SEARCHLIST>/I<REPLACEMENTLIST>/> has been fixed.  Only the first
instance is supposed to be meaningful if a character appears more than
once in C<I<SEARCHLIST>>.  Under some circumstances, the final instance
was overriding all earlier ones.  [perl #113584]

=item *

C<B::COP::stashlen> has been added.   This provides access to an internal
field added in perl 5.16 under threaded builds.  It was broken at the last
minute before 5.16 was released [perl #113034].

=item *

The L<re> pragma will no longer clobber C<$_>. [perl #113750]

=item *

Unicode 6.1 published an incorrect alias for one of the
Canonical_Combining_Class property's values (which range between 0 and
254).  The alias C<CCC133> should have been C<CCC132>.  Perl now
overrides the data file furnished by Unicode to give the correct value.

=item *

Duplicating scalar filehandles works again.  [perl #113764]

=item *

Under threaded perls, a runtime code block in a regular expression could
corrupt the package name stored in the op tree, resulting in bad reads
in C<caller>, and possibly crashes [perl #113060].

=item *

For efficiency's sake, many operators and built-in functions return the
same scalar each time.  Lvalue subroutines and subroutines in the CORE::
namespace were allowing this implementation detail to leak through.
C<print &CORE::uc("a"), &CORE::uc("b")> used to print "BB".  The same thing
would happen with an lvalue subroutine returning the return value of C<uc>.
Now the value is copied in such cases [perl #113044].

=item *

C<__SUB__> now works in special blocks (C<BEGIN>, C<END>, etc.).

=item *

Formats that reference lexical variables from outside no longer result
in crashes.

=back

=head1 Known Problems

There are no new known problems, but consult L<perl5160delta/Known
Problems> to see those identified in the 5.16.0 release.

=head1 Acknowledgements

Perl 5.16.1 represents approximately 2 months of development since Perl
5.16.0 and contains approximately 14,000 lines of changes across 96
files from 8 authors.

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 5.16.1:

Chris 'BinGOs' Williams, Craig A. Berry, Father Chrysostomos, Karl
Williamson, Paul Johnson, Reini Urban, Ricardo Signes, Tony Cook.

The list above is almost certainly incomplete as it is automatically
generated from version control history. In particular, it does not
include the names of the (very much appreciated) contributors who
reported issues to the Perl bug tracker.

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.

For a more complete list of all of Perl's historical contributors,
please see the F<AUTHORS> file in the Perl source distribution.

=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 will 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.

=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

MR SKB