perldelta for f57000b

[perl5.git] / pod / perldelta.pod

=encoding utf8

=head1 NAME

[ this is a template for a new perldelta file.  Any text flagged as XXX needs
to be processed before release. ]

perldelta - what is new for perl v5.21.3

=head1 DESCRIPTION

This document describes differences between the 5.21.2 release and the 5.21.3
release.

If you are upgrading from an earlier release such as 5.21.1, first read
L<perl5212delta>, which describes differences between 5.21.1 and 5.21.2.

=head1 Notice

XXX Any important notices here

=head1 Core Enhancements

=head2 C<defined(@array = LIST)> is no longer fatal

In 5.21.1, C<defined(@array)> was made fatal.  This has been relaxed
to not die if the argument is assigning to an array.

=head1 Security

=head2 The L<Safe> module could allow outside packages to be replaced

Critical bugfix: outside packages could be replaced.  L<Safe> has
been patched to 2.38 to address this.

=head1 Incompatible Changes

=head2 S<C<use UNIVERSAL '...'>> is now a fatal error

Importing functions from C<UNIVERSAL> has been deprecated since v5.12, and
is now a fatal error.  S<C<"use UNIVERSAL">> without any arguments is still
allowed.

=head1 Deprecations

XXX Any deprecated features, syntax, modules etc. should be listed here.

[ List each other deprecation as a =head2 entry ]

=head1 Performance Enhancements

XXX Changes which enhance performance without changing behaviour go here.
There may well be none in a stable release.

[ List each enhancement as a =item entry ]

=over 4

=item *

XXX

=back

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<B::Debug> has been upgraded from version 1.19 to 1.21

=item *

L<Config::Perl::V> has been upgraded from version 0.20 to 0.22.

=item *

L<CPAN::Meta> has been upgraded from version 2.141520 to 2.142060.

=item *

L<CPAN::Meta::Requirements> has been upgraded from version 2.125 to 2.126.

=item *

L<ExtUtils::Manifest> has been upgraded from version 1.64 to 1.65.

The MANIFEST is now opened with C<:raw>, to prevent C<CRLF>s leaking in.

=item *

L<HTTP::Tiny> has been upgraded from version 0.043 to 0.047.

=item *

L<perl5db.pl> has been upgraded from version 1.45 to 1.46.

Fixed the scope level handling of the debugger's C<y> command.

=item *

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

Replaced the thread-unsafe code used to prevent duplicate warning
messages for using the isxxx() functions.  [perl #122476]

=item *

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

Critical bugfix: outside packages could be replaced.

=item *

L<Socket> has been upgraded from version 2.014 to 2.015.

Test suite updates, particularly useful for Solaris and cygwin, and
a slight change to the pattern used for IPv4 address matching.

=back

=head1 Documentation

=head2 Changes to Existing Documentation

=head3 L<perlexperiment>

=over 4

=item *

Added reference to L<feature>.

=back

=head3 L<perlguts>

=over 4

=item *

Details on C level symbols and libperl.t added.

=back

=head3 L<perlhacktips>

=over 4

=item *

Recommended replacements for tmpfile, atoi, strtol, and strtoul added.
 
=back

=head3 L<perlop>

=over 4

=item *

ASCII v. EBCDIC clarifications added.

=back

=head3 L<perlsec>

=over 4

=item *

Comments added on algorithmic complexity and tied hashes.

=back

=head3 L<perlvms>

=over 4

=item *

Updated documentation on environment and shell interaction in VMS.

=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>.

XXX New or changed warnings emitted by the core's C<C> code go here.  Also
include any changes in L<perldiag> that reconcile it to the C<C> code.

=head2 New Diagnostics

XXX Newly added diagnostic messages go under here, separated into New Errors
and New Warnings

=head3 New Errors

=over 4

=item *

XXX L<message|perldiag/"message">

=back

=head3 New Warnings

=over 4

=item *

L<Hexadecimal float: exponent overflow|perldiag/"Hexadecimal float: exponent overflow">

(W overflow) The hexadecimal floating point has larger exponent
than the floating point supports.

=item *

L<Hexadecimal float: exponent underflow|perldiag/"Hexadecimal float: exponent underflow">

(W overflow) The hexadecimal floating point has smaller exponent
than the floating point supports.

=item *

L<Hexadecimal float: internal error|perldiag/"Hexadecimal float: internal error">

(F) Something went horribly bad in hexadecimal float handling.

=item *

L<Hexadecimal float: mantissa overflow|perldiag/"Hexadecimal float: mantissa overflow">

(W overflow) The hexadecimal floating point literal had more bits in
the mantissa (the part between the 0x and the exponent, also known as
the fraction or the significand) than the floating point supports.

=item *

L<Hexadecimal float: precision loss|perldiag/"Hexadecimal float: precision loss">

(W overflow) The hexadecimal floating point had internally more
digits than could be output.  This can be caused by unsupported
long double formats, or by 64-bit integers not being available
(needed to retrieve the digits under some configurations).

=item *

L<Hexadecimal float: unsupported long double format|perldiag/"Hexadecimal float: unsupported long double format">

(F) You have configured Perl to use long doubles but
the internals of the long double format are unknown,
therefore the hexadecimal float output is impossible.

=back

=head2 Changes to Existing Diagnostics

XXX Changes (i.e. rewording) of diagnostic messages go here

=over 4

=item *

XXX Describe change here

=back

=head1 Configuration and Compilation

XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
go here.  Any other changes to the Perl build process should be listed here.
However, any platform-specific changes should be listed in the
L</Platform Support> section, instead.

[ List changes as a =item entry ].

=over 4

=item *

Internal handling of floating point values has been improved.

=back

=head1 Testing

XXX Any significant changes to the testing of a freshly built perl should be
listed here.  Changes which create B<new> files in F<t/> go here as do any
large changes to the testing harness (e.g. when parallel testing was added).
Changes to existing files in F<t/> aren't worth summarizing, although the bugs
that they represent may be covered elsewhere.

[ List each test improvement as a =item entry ]

=over 4

=item *

XXX

=back

=head1 Platform Support

XXX Any changes to platform support should be listed in the sections below.

[ Within the sections, list each platform as a =item entry with specific
changes as paragraphs below it. ]

=head2 Platform-Specific Notes

XXX List any changes for specific platforms.  This could include configuration
and compilation changes or changes in portability/compatibility.  However,
changes within modules for platforms should generally be listed in the
L</Modules and Pragmata> section.

=over 4

=item XXX-some-platform

XXX

=back

=head1 Internal Changes

XXX Changes which affect the interface available to C<XS> code go here.  Other
significant internal changes for future core maintainers should be noted as
well.

[ List each change as a =item entry ]

=over 4

=item *

Added L<perlapi/sync_locale>.
Changing the program's locale should be avoided by XS code.  Nevertheless,
certain non-Perl libraries called from XS, such as C<Gtk> do so.  When this
happens, Perl needs to be told that the locale has changed.  Use this function
to do so, before returning to Perl.

=back

=head1 Selected Bug Fixes

XXX Important bug fixes in the core language are summarized here.  Bug fixes in
files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.

[ List each fix as a =item entry ]

=over 4

=item *

Failing to compile C<use Foo> in an eval could leave a spurious
C<BEGIN> subroutine definition, which would produce a "Subroutine
BEGIN redefined" warning on the next use of C<use>, or other C<BEGIN>
block.  [perl #122107]

=item *

C<method { BLOCK } ARGS> syntax now correctly parses the arguments if they
begin with an opening brace.  [perl #46947]

=item *

External libraries and Perl may have different ideas of what the locale is.
This is problematic when parsing version strings if the locale's numeric
separator has been changed.  Version parsing has been patched to ensure
it handles the locales correctly.  [perl #121930]

=back

=head1 Known Problems

XXX Descriptions of platform agnostic bugs we know we can't fix go here.  Any
tests that had to be C<TODO>ed for the release would be noted here.  Unfixed
platform specific bugs also go here.

[ List each fix as a =item entry ]

=over 4

=item *

XXX

=back

=head1 Errata From Previous Releases

=over 4

=item *

XXX Add anything here that we forgot to add, or were mistaken about, in
the perldelta of a previous release.

=back

=head1 Acknowledgements

XXX Generate this with:

  perl Porting/acknowledgements.pl v5.21.2..HEAD

=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
https://rt.perl.org/ .  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