=encoding utf8

=head1 NAME

perl5395delta - what is new for perl v5.39.5

=head1 DESCRIPTION

This document describes differences between the 5.39.4 release and the 5.39.5
release.

If you are upgrading from an earlier release such as 5.39.3, first read
L<perl5394delta>, which describes differences between 5.39.3 and 5.39.4.

=head1 Notice

glibc has an undocumented feature to return the current locale when
using the POSIX 2008 locale API.  This feature is now experimentally
enabled by default so as to see if there are problems with it.  This
enabling expires in v5.39.10.  In the meantime, if you run into
problems, open a bug ticket and Configure with
C<-Accflags=-DNO_NL_LOCALE_NAME> to turn it off.

=head1 Deprecations

=over 4

=item *

Using C<goto> to jump from an outer scope into an inner scope is deprecated
and will be removed completely in Perl 5.42.  [L<GH #21601|https://github.com/Perl/perl5/issues/21601>]

=back

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<Benchmark> has been upgraded from version 1.24 to 1.25.

=item *

L<builtin> has been upgraded from version 0.011 to 0.012.

Added the C<load_module()> builtin function as per L<PPC 0006|https://github.com/Perl/PPCs/blob/main/ppcs/ppc0006-load-module.md>.

=item *

L<Encode> has been upgraded from version 3.19 to 3.20.

=item *

L<Getopt::Long> has been upgraded from version 2.54 to 2.57.

=item *

L<IO> has been upgraded from version 1.53 to 1.54.

Fixed C<IO::Handle/blocking> on Windows, which has been non-functional
since IO 1.32.  [L<GH #17455|https://github.com/Perl/perl5/issues/17455>]

=item *

L<locale> has been upgraded from version 1.10 to 1.11.

=item *

L<Math::BigInt> has been upgraded from version 1.999842 to 2.001000.

=item *

L<Module::CoreList> has been upgraded from version 5.20231025 to 5.20231120.

=item *

L<POSIX> has been upgraded from version 2.16 to 2.17.

Adjusted the signbit() on NaN test to handle the unusual bit pattern
returned for NaN by Oracle Developer Studio's compiler.  [L<GH #21533|https://github.com/Perl/perl5/issues/21533>]

=item *

L<Term::Table> has been upgraded from version 0.017 to 0.018.

=item *

L<Test2::Suite> has been upgraded from version 0.000156 to 0.000159.

=back

=head1 Documentation

=head2 Changes to Existing Documentation

We have attempted to update the documentation to reflect the changes
listed in this document.  If you find any we have missed, open an issue
at L<https://github.com/Perl/perl5/issues>.

Additionally, the following selected changes have been made:

=head3 L<perlop>

=over 4

=item *

The section on the empty pattern C<//> has been amended to mention that the current dynamic scope is
used to find the last successful match.

=back

=head1 Testing

Tests were added and changed to reflect the other additions and
changes in this release.  Furthermore, these significant changes were
made:

=over 4

=item *

F<porting/globvar.t> now uses the more portable C<nm -P ...> to fetch
the names defined in an object file.  The parsing of the names found
in the object is now separated from processing them to handle the
duplication between local and global definitions on AIX.  [L<GH #21637|https://github.com/Perl/perl5/issues/21637>]

=item *

A test was added to F<lib/locale_threads.t> that extensively stress
tests locale handling.  It turns out that the libc implementations on
various platforms have bugs in this regard, including Linux, Windows,
*BSD derivatives including Darwin, and others.  Experimental versions of
this test have been used in the past few years to find bugs in the Perl
implementation and in those platforms, as well as to develop workarounds
in the Perl implementation, where feasible, for the platform bugs.
Multiple bug report tickets have been filed against platforms, and some
have been fixed.  The test checks that platforms that purport to support
thread-safe locale handling actually do so (and that perl works properly
on those that do;  The read-only variable C<${^SAFE_LOCALES}> is set to
1 if perl thinks the platform can handle this, whatever the platform's
documentation says).

Also tested for is if the various locale categories can indeed be set
independently to disparate locales.  (An example of where you might want
to do this is if you are a Western Canadian living and working in
Holland.  You likely will want to have the C<LC_MONETARY> locale be
set to where you are living, but have the other parts of your locale
retain your native English values.  Later, as you get a bit more
comfortable with Dutch, and in order to communicate better with your
colleagues, you might want to change C<LC_TIME> and C<LC_NUMERIC> to
Dutch, while leaving C<LC_CTYPE> and C<LC_COLLATE> set to English
indefinitely.)

=back

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item Oracle Developer Studio (Solaris, Oracle Linux)

Due to an apparent code generation bug, the default optimization level
for the Oracle Developer Studio (formerly Sun Workshop) compiler is
now C<-xO1>. [L<GH #21535|https://github.com/Perl/perl5/issues/21535>]

=item Windows

Enable C<copysign>, C<signbit>, C<acosh>, C<asinh>, C<atanh>, C<exp2>,
C<tgamma> in the bundled configuration used for MSVC.  [L<GH #21610|https://github.com/Perl/perl5/issues/21610>]

The build process no longer supports Visual Studio 2013.  This was
failing to build at a very basic level and there has been no reports
of such failures.  [L<GH #21624|https://github.com/Perl/perl5/issues/21624>]

=back

=head1 Errata From Previous Releases

=over 4

=item *

L<perl5300delta> has been updated to include the removal of the C<arybase> module that happened at
the same time as the removal of C<$[>.

=back

=head1 Acknowledgements

Perl 5.39.5 represents approximately 4 weeks of development since Perl
5.39.4 and contains approximately 12,000 lines of changes across 330 files
from 17 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 8,200 lines of changes to 270 .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 5.39.5:

Chad Granum, Dan Kogai, E. Choroba, Elvin Aslanov, Graham Knop, Hugo van der
Sanden, James E Keenan, Johan Vromans, Karen Etheridge, Karl Williamson,
Leon Timmermans, Lukas Mai, Marco Fontani, Paul Evans, Peter John Acklam,
Tony Cook, Yves Orton.

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<http://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
