=encoding utf8

=head1 NAME

perl5416delta - what is new for perl v5.41.6

=head1 DESCRIPTION

This document describes differences between the 5.41.5 release and the 5.41.6
release.

If you are upgrading from an earlier release such as 5.41.4, first read
L<perl5415delta>, which describes differences between 5.41.4 and 5.41.5.

=head1 Performance Enhancements

=over 4

=item *

Code that uses the C<indexed> function from the L<builtin> module to generate
a list of index/value pairs out of array which is then passed into a
two-variable C<foreach> list to unpack those again is now optimised to be more
efficient.

    my @array = (...);

    foreach my ($idx, $val) (builtin::indexed @array) {
        ...
    }

In particular, a temporary list twice the size of the original
array is no longer generated.  Instead, the list iterates down the array
in-place directly, in the same way that C<foreach (@array)> would do.

=back

=head1 Incompatible Changes

=head2 Apostrophe is again recognized as a global name separator

This was deprecated in Perl 5.38 and removed as scheduled in perl
5.41.3, but after some discussion has been reinstated by default.

This can be controlled with the C<apostrophe_as_package_separator>
feature which is enabled by default, but is disabled from the 5.41
feature bundle onwards.

If you want to disable use within your own code you can explicitly
disable the feature:

  no feature "apostrophe_as_package_separator";

Note that disabling this feature only prevents use of apostrophe as a
package separator within code; symbolic references still treat C<'> as
C<::> with the feature disabled:

  my $symref = "My'Module'Var";
  # default features
  my $x = $My'Module'Var; # fine
  no feature "apostrophe_as_package_separator";
  no strict "refs";
  my $y = $$symref;       # like $My::Module::Var
  my $z = $My'Module'Var; # syntax error

[L<GH #22644|https://github.com/Perl/perl5/issues/22644>]

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<B::Deparse> has been upgraded from version 1.78 to 1.80.

It now retains parens around logical negations on the left-hand side of
comparisons (such as C<(!$x) == $y>) because omitting them would trigger a
C<Possible precedence problem> warning since perl v5.41.4. [L<GH #22661|https://github.com/Perl/perl5/issues/22661>]

=item *

L<builtin> has been upgraded from version 0.015 to 0.016.

=item *

L<CPAN> has been upgraded from version 2.37 to 2.38.

=item *

L<DB> has been upgraded from version 1.08 to 1.09.

=item *

L<ExtUtils::ParseXS> has been upgraded from version 3.55 to 3.56.

=item *

L<ExtUtils::Typemaps> has been upgraded from version 3.55 to 3.56.

=item *

L<feature> has been upgraded from version 1.91 to 1.92.

=item *

L<fields> has been upgraded from version 2.25 to 2.26.

=item *

L<HTTP::Tiny> has been upgraded from version 0.088 to 0.090.

=item *

L<IPC::Open3> has been upgraded from version 1.23 to 1.24.
L<IPC::Open2> has been upgraded from version 1.07 to 1.08.

There is now a way to pass lexical filehandles to child processes directly
(instead of having the module create a pipe internally). Previously, only
bareword filehandles could be used in "dup mode".

=item *

L<Math::Complex> has been upgraded from version 1.62 to 1.63.

The complex number parser for string inputs has been improved. In particular,
C<1+i>, C<123i>, C<inf>, C<-inf>, C<infi>, and C<-infi> are now handled
correctly.

=item *

L<Memoize> has been upgraded from version 1.16 to 1.17.

=item *

L<Module::CoreList> has been upgraded from version 5.20241020 to 5.20241120.

=item *

L<NDBM_File> has been upgraded from version 1.17 to 1.18.

=item *

L<ODBM_File> has been upgraded from version 1.18 to 1.19.

=item *

L<parent> has been upgraded from version 0.242 to 0.242_001.

=item *

L<POSIX> has been upgraded from version 2.22 to 2.23.

=item *

L<Scalar::Util> has been upgraded from version 1.68 to 1.68_01.

=item *

L<Term::Table> has been upgraded from version 0.022 to 0.023.

=item *

L<warnings> has been upgraded from version 1.70 to 1.71.

=back

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item arm64 DARWIN

Fix arm64 darwin hints when using use64bitall with Configure [L<GH #22672|https://github.com/Perl/perl5/issues/22672>]

=item Android

Changes to perl_langinfo.h for Android [L<GH #22650|https://github.com/Perl/perl5/issues/22650>] related to [L<GH #22627|https://github.com/Perl/perl5/issues/22627>]

=item Cygwin

cygwin.c: fix several silly/terrible C errors [L<GH #22724|https://github.com/Perl/perl5/issues/22724>]

workaround DLL load address conflict [L<GH #22696|https://github.com/Perl/perl5/issues/22696>]

=back

=head1 Internal Changes

=over 4

=item *

Enable removing most of mathoms.c and stub functions [L<GH #22691|https://github.com/Perl/perl5/issues/22691>] and [L<GH #22714|https://github.com/Perl/perl5/issues/22714>]

=item *

reinstate apostrophe as package separator behind a default enabled feature, 
which is disabled from feature bundle 5.41.

=item *

pp_reverse: don't COW buffer just to then un-COW it [L<GH #22729|https://github.com/Perl/perl5/issues/22729>]

=back

=head1 Selected Bug Fixes

=over 4

=item *

The perl parser would erroneously parse like C<=cut> some other POD directives
whose names start with I<cut>, prematurely terminating an embedded POD section.
The following cases were affected: I<cut> followed by a digit (e.g.
C<=cut2studio>), I<cut> followed by an underscore (e.g. C<=cut_grass>), and in
string C<eval>, any identifier starting with I<cut> (e.g. C<=cute>).
[L<GH #22759|https://github.com/Perl/perl5/issues/22759>]

=item *

Builds with C<-msse> and quadmath on 32-bit x86 systems would crash
with a misaligned access early in the build. [L<GH #22577|https://github.com/Perl/perl5/issues/22577>]

=item *

On threaded builds on POSIX-like systems, if the perl signal handler
receives we now resend the signal to the main perl thread.  Previously
this would crash.  [GH #22487]

=back

=head1 Known Problems

=over 4

=item *

C<cygwin> builds may fail during testing due to a conflict between the
load addresses of F<cygperl5_41_6.dll> and
F<olib/auto/I18N/Langinfo/Langinfo.dll>.  This will also be visible
for anything that attempts to fork() with C<I18N::LangInfo> loaded.

This is known to fail for builds with options that increase the size
of the binary, such as C<-DDEBUGGING>, C<-Doptimize="-O0 -g"> or
C<-Doptimize="-O2 -g -march=x86-64-v2">.

This can be avoided by building perl with
C<-Astatic_ext=I18N/Langinfo>.

The base addresses are generated by the linker based on the names of
the DLLs, so this is expected to clear up for 5.41.7.

[L<GH #22695|https://github.com/Perl/perl5/issues/22695>]

=back

=head1 Acknowledgements

Perl 5.41.6 represents approximately 4 weeks of development since Perl
5.41.5 and contains approximately 8,400 lines of changes across 180 files
from 14 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 6,700 lines of changes to 120 .pm, .t, .c and .h files.

Perl continues to flourish into its fourth decade thanks to a vibrant
community of users and developers. The following people are known to have
contributed the improvements that became Perl 5.41.6:

Chad Granum, Chris 'BinGOs' Williams, Daniel Dragan, David Mitchell, Graham
Knop, James E Keenan, Karl Williamson, Lukas Mai, Marin Tsanov, Paul Evans,
pyrrhlin, Richard Leach, Thibault Duponchelle, 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 perl bug database
at L<https://github.com/Perl/perl5/issues>. There may also be information at
L<https://www.perl.org/>, the Perl Home Page.

If you believe you have an unreported bug, please open an issue at
L<https://github.com/Perl/perl5/issues>. Be sure to trim your bug down to a
tiny but sufficient test case.

If the bug you are reporting has security implications which make it
inappropriate to send to a public issue tracker, then see
L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
for details of how to report the issue.

=head1 Give Thanks

If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
you can do so by running the C<perlthanks> program:

    perlthanks

This will send an email to the Perl 5 Porters list with your show of thanks.

=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
