=encoding utf8

=head1 NAME

perldelta - what is new for perl v5.39.4

=head1 DESCRIPTION

This document describes differences between the 5.39.3 release and the 5.39.4
release.

If you are upgrading from an earlier release such as 5.39.2, first read
L<perl5393delta>, which describes differences between 5.39.2 and 5.39.3.

=head1 Modules and Pragmata

=head2 New Modules and Pragmata

=over 4

=item *

L<Term::Table> 0.017 has been added to the Perl core.

This module is a dependency of L<Test2::Suite>.

=item *

L<Test2::Suite> 0.000156 has been added to the Perl core.

This distribution contains a comprehensive set of test tools for writing unit
tests.  It is the successor to L<Test::More> and similar modules.  Its
inclusion in the Perl core means that CPAN module tests can be written using
this suite of tools without extra dependencies.

=back

=head2 Updated Modules and Pragmata

=over 4

=item *

L<builtin> has been upgraded from version 0.010 to 0.011.

L<builtin> now accepts a version bundle as an input argument, requesting it to
import all of the functions that are considered a stable part of the module at
the given Perl version. For example:

    use builtin ':5.40';

=item *

L<feature> has been upgraded from version 1.84 to 1.85.

It now documents the C<:all> feature bundle, and suggests a reason why you may
not wish to use it.

=item *

L<File::Find> has been upgraded from version 1.43 to 1.44.

=item *

L<File::stat> has been upgraded from version 1.13 to 1.14.

=item *

L<Math::BigInt> has been upgraded from version 1.999839 to 1.999842.

=item *

L<Math::BigInt::FastCalc> has been upgraded from version 0.5014 to 0.5015.

=item *

L<Module::CoreList> has been upgraded from version 5.20230920 to 5.20231025.

=item *

L<perl5db.pl> has been upgraded from version 1.77 to 1.78.

Made parsing of the C<l> command arguments saner.
[L<GH #21350|https://github.com/Perl/perl5/issues/21350>]

=item *

L<POSIX> has been upgraded from version 2.15 to 2.16.

The C<mktime> function now works correctly on 32-bit platforms even if the
platform's C<time_t> type is larger than 32 bits. [L<GH #21551|https://github.com/Perl/perl5/issues/21551>]

The C<T_SIGNO> and C<T_FD> typemap entries have been fixed so they work with
any variable name, rather than just the hardcoded C<sig> and C<fd>.

The mappings for C<Mode_t>, C<pid_t>, C<Uid_t>, C<Gid_t> and C<Time_t> have
been updated to be integer types; previously they were C<NV> floating-point.

=item *

L<Test::Harness> has been upgraded from version 3.47 to 3.48.

=item *

L<Time::gmtime> has been upgraded from version 1.04 to 1.05.

=item *

L<Time::localtime> has been upgraded from version 1.03 to 1.04.

=item *

L<Time::tm> has been upgraded from version 1.00 to 1.01.

=item *

L<User::grent> has been upgraded from version 1.04 to 1.05.

=item *

L<User::pwent> has been upgraded from version 1.02 to 1.03.

=item *

L<version> has been upgraded from version 0.9929 to 0.9930.

=item *

L<XS::APItest> has been upgraded from version 1.33 to 1.34.

=item *

L<XS::Typemap> has been upgraded from version 0.19 to 0.20.

=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<perlre>

=over 4

=item *

Removed statement suggesting C</p> is a no-op.

=back

=head3 L<perlapi>

=over 4

=item *

Several internal functions now have documentation - the various C<newSUB>
functions, C<newANONLIST()>, C<newANONHASH()>, C<newSVREF()> and similar.

=back

=head1 Diagnostics

The following additions or changes have been made to diagnostic output,
including warnings and fatal error messages.  For the complete list of
diagnostic messages, see L<perldiag>.

=head2 New Diagnostics

=head3 New Errors

=over 4

=item *

L<Builtin version bundle "%s" is not supported by Perl|perldiag/Builtin version bundle "%s" is not supported by Perl>

(F) You attempted to C<use builtin :ver> for a version number that is either
older than 5.39 (when the ability was added), or newer than the current perl
version.

=item *

L<Invalid version bundle "%s"|perldiag/Invalid version bundle "%s">

(F) A version number that is used to specify an import bundle during a
C<use builtin ...> statement must be formatted as C<:MAJOR.MINOR> with an
optional third component, which is ignored.  Each component must be a number
of 1 to 3 digits. No other characters are permitted.  The value that was
specified does not conform to these rules.

=back

=head1 Testing

Tests were added and changed to reflect the other additions and changes
in this release.

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item VMS

Fixed the configure "installation prefix" prompt to accept a string rather than
yes/no.

Fixed compilation by defining proper value for
C<perl_lc_all_category_positions_init>.

Increased buffer size when reading F<config_H.SH> to fix compilation under
clang.

=back

=head1 Internal Changes

=over 4

=item *

C<PERL_VERSION_LE> has been fixed to properly check for "less than or equal"
rather than "less than".

=back

=head1 Selected Bug Fixes

=over 4

=item *

Lexical names from the enclosing scope in a lexical sub or closure
weren't visible to code executed by calling C<eval EXPR;> from the
C<DB> package.  This was introduced in 5.18 in an attempt to prevent
subs from retaining a reference to their outer scope, but this broke
the special behaviour of C<eval EXPR;> in package DB.

This incidentally fixed a TODO test for C<B::Deparse>.
[L<GH #19370|https://github.com/Perl/perl5/pull/19370>]

=item *

Optionally support an argument stack over 2**32 entries on 64-bit
platforms.  This requires 32GB of memory just for the argument stack
pointers itself, so you will require a significantly more memory to
take advantage of this.

To enable this add C<-Accflags=-DPERL_STACK_OFFSET_SSIZET> or
equivalent to the C<Configure> command-line.

[L<GH #20917|https://github.com/Perl/perl5/issues/20917>]
[L<GH #21523|https://github.com/Perl/perl5/issues/21523>]

=item *

Fixed various problems with join() where modifications to the
separator could be handled inconsistently, or could access released
memory.  Changes to the separator from magic or overloading for values
in the C<LIST> no longer have an effect on the resulting joined
string.
[L<GH #21458|https://github.com/Perl/perl5/issues/21458>]

=item *

Don't clear the integer flag C<IOK> from lines in the C<<
@{"_<$sourcefile"} >> array when a C<dbstate> op is removed for that
line.  This was broken when fixing
[L<GH #19198|https://github.com/Perl/perl5/issues/19198>].
[L<GH #21564|https://github.com/Perl/perl5/issues/21564>]

=item *

Many bug fixes have been made for using locales under threads and in
embedded perls.  And workarounds for libc bugs have been added.  As a
result thread-safe locale handling is now the default under OpenBSD, and
MingW when compiled with UCRT.

However, testing has shown that Darwin's implementation of thread-safe
locale handling has bugs.  So now Perl doesn't attempt to use the
thread-safe operations when compiled on Darwin.

As before, you can check to see if your program is running with
thread-safe locales by checking if the value of C<${^SAFE_LOCALES}> is
1.

=item *

Various bugs have been fixed when perl is configured with
C<-Accflags=-DNO_LOCALE_NUMERIC> or any other locale category (or
categories).

=item *

Not all locale categories need be set to the same locale.  Perl now
works around bugs in the libc implementations of locale handling on some
platforms that previously could result in mojibake.

=item *

C<LC_ALL> is represented in one of two ways when not all locale
categories are set to the same locale.  On some platforms, such as Linux
and Windows, the representation is of the form of a series of
C<'category=locale-name'> pairs.  On other platforms, such as *BSD, the
representation is positional like S<C<I<name1> / I<name2> / ... >>.
I<name1> is always for a particular category as defined by the platform,
as are the other names.  The sequence that separates the names
(the S<C< / >> above) also varies by platform.  Previously, perl had
problems with platforms that used the positional notation.  This is now
fixed.

=item *

A bug has been fixed in the regexp engine with an optimisation that applies
to the C<+> quantifier where it was followed by a C<(*SKIP)> pattern.

[L<GH #21534|https://github.com/Perl/perl5/issues/21534>]

=back

=head1 Acknowledgements

Perl 5.39.4 represents approximately 5 weeks of development since Perl
5.39.3 and contains approximately 46,000 lines of changes across 460 files
from 20 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 44,000 lines of changes to 390 .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 5.39.4:

Abe Timmerman, Amory Meltzer, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan
Jacobson, Elvin Aslanov, Gianni Ceccarelli, Graham Knop, Jake Hamby, James E
Keenan, Joe McMahon, Karl Williamson, Leon Timmermans, Lukas Mai, Matthew
Horsfall, Paul Evans, Peter John Acklam, Tony Cook, William Lyu, 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