Revert "Strengthen weak refs when sorting in-place"

[perl5.git] / pod / perl52710delta.pod

=encoding utf8

=head1 NAME

perl52710delta - what is new for perl v5.27.10

=head1 DESCRIPTION

This document describes differences between the 5.27.9 release and the 5.27.10
release.

If you are upgrading from an earlier release such as 5.27.8, first read
L<perl5279delta>, which describes differences between 5.27.8 and 5.27.9.

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<attributes> has been upgraded from version 0.32 to 0.33

=item *

L<B::Deparse> has been upgraded from version 1.47 to 1.48.

=item *

L<Carp> has been upgraded from version 1.46 to 1.49.

L<Carp>, when generating stack traces, now attempts to work around
longstanding bugs resulting from Perl's non-reference-counted stack.
[perl #52610]

Carp has been modified to avoid assuming that objects cannot be
overloaded without the L<overload> module loaded (this can happen with
objects created by XS modules).  Previously, infinite recursion would
result if an XS-defined overload method itself called Carp.  [perl #132828]

Carp now avoids using C<overload::StrVal>, partly because older versions
of L<overload> (included with perl 5.14 and earlier) load L<Scalar::Util>
at run time, which will fail if Carp has been invoked after a syntax error.

L<I18N::Langinfo> has been upgraded from version 0.15 to 0.16.

This module is now available on all platforms, emulating the system
L<nl_langinfo(3)> on systems that lack it.  Some caveats apply, as
L<detailed in its documentation|I18N::Langinfo>, the most severe being
that, except for MS Windows, the C<CODESET> item is not implemented on
those systems, always returning C<"">.

It now sets the UTF-8 flag in its returned scalar if the string contains
legal non-ASCII UTF-8, and the locale is UTF-8 ([perl #127288].

=item *

L<Encode> has been upgraded from version 2.96 to 2.97.

=item *

L<ExtUtils::MakeMaker> has been upgraded from version 7.32 to 7.34.

=item *

L<ExtUtils::ParseXS> has been upgraded from version 3.38 to 3.39

=item *

L<File::Glob> has been upgraded from version 1.30 to 1.31.

=item *

L<I18N::Langinfo> has been upgraded from version 0.15 to 0.16.

=item *

L<Locale::Codes> has been upgraded from version 3.55 to 3.56.

=item *

L<Module::CoreList> has been upgraded from version 5.20180220 to 5.20180221.

=item *

L<POSIX> has been upgraded from version 1.82 to 1.83.

=item *

L<Scalar::Util> has been upgraded from version 1.49 to 1.50.

=item *

L<Test::Harness> has been upgraded from version 3.39 to 3.42.

=item *

L<Test::Simple> has been upgraded from version 1.302122 to 1.302133.

=item *

L<Time::HiRes> has been upgraded from version 1.9753 to 1.9757.

=item *

L<Time::Piece> has been upgraded from version 1.3203 to 1.3204.

=item *

L<warnings> has been upgraded from version 1.41 to 1.42.

=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, send email
to L<perlbug@perl.org|mailto:perlbug@perl.org>.

Additionally, the following selected changes have been made:

=head3 L<perlfunc>

=over 4

=item *

Clarification to require was added to show that

        require "Foo/Bar.pm";

is equivalent to:

        eval "require Foo::Bar";

=back

=head3 L<perlguts>

=over 4

=item *

Improve documentation related to UTF-8 multibytes.

=back

=head3 L<perlrequick>

=over 4

=item *

Clarifications on metacharacters and character classes

=back

=head3 L<perlretut>

=over 4

=item *

Clarify metacharacters.

=back

=head1 Diagnostics

=head2 Changes to Existing Diagnostics

=over 4

=item *

The new (as of 5.27.8) restriction forbidding use of C<goto> to enter the
argument of a binary or list expression (see L<perldiag/"Can't
E<quot>gotoE<quot> into a binary or list expression">) has been relaxed to
allow entering the I<first> argument of an operator that takes a fixed
number of arguments, since this is a case that will not cause stack
corruption.  [perl #132854]

=item *

The warning added in 5.27.8 concerning UTF-8 locale compatibility was
misleading.  The new wording and explanation are at
L<perldiag/Locale '%s' contains (at least) the following characters which
have unexpected meanings: %s  The Perl program will use the expected
meanings>

=back

=head1 Configuration and Compilation

=over 4

=item *

F<lib/unicore/mktables> now correctly canonicalizes the names of the
dependencies stored in the files it generates.

F<regen/mk_invlists.pl>, unlike the other F<regen/*.pl> scripts, used
C<$0> to name itself in the dependencies stored in the files it
generates.  It now uses a literal so that the path stored in the
generated files doesn't depend on how F<regen/mk_invlists.pl> is
invoked.

This lack of canonical names could cause test failures in
F<t/porting/regen.t>.  [perl #132925]

=back

=head1 Testing

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

=head1 Internal Changes

=over 4

=item *

The item names passed to the function L<perlapi/Perl_langinfo>,
introduced in 5.27.4, may no longer be prefixed with C<PERL_>.  For
example, if you want the current floating point radix character, you
must call it like C<Perl_langinfo(RADIXCHAR)>.

=back

=head1 Selected Bug Fixes

=over 4

=item *

Blead Breaks CPAN: FELIPE/Crypt-Perl [perl #132900]

=item *

Prevent duplicate Config.pm vars [perl #132834]

=item *

Regex assertion failure [perl #132163]

=item *

fix line numbers in multi-line s///

=item *

add an empty file (to be removed next commit)

=item *

warnings.pm: sprintf is faster than concat

=back

=head1 Acknowledgements

Perl 5.27.10 represents approximately 4 weeks of development since Perl
5.27.9 and contains approximately 80,000 lines of changes across 380 files
from 18 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 75,000 lines of changes to 270 .pm, .t, .c and .h files.

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 5.27.10:

Aaron Crane, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, David
Mitchell, Father Chrysostomos, H.Merijn Brand, James E Keenan, Karl
Williamson, Pali, Renee Baecker, Sawyer X, Shoichi Kaji, Steve Hay, Todd
Rinaldo, Tony Cook, Yves Orton, Zefram.

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://rt.perl.org/> .  There may also be information at
L<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 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