Unicode::Collate has been upgraded from version 1.11 to 1.12

[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 v5.21.10

=head1 DESCRIPTION

This document describes differences between the 5.21.9 release and the 5.21.10
release.

If you are upgrading from an earlier release such as 5.21.8, first read
L<perl5219delta>, which describes differences between 5.21.8 and 5.21.9.

=head1 Notice

XXX Any important notices here

=head1 Core Enhancements

XXX New core language features go here.  Summarize user-visible core language
enhancements.  Particularly prominent performance optimisations could go
here, but most should go in the L</Performance Enhancements> section.

[ List each enhancement as a =head2 entry ]

=head1 Security

XXX Any security-related notices go here.  In particular, any security
vulnerabilities closed should be noted here rather than in the
L</Selected Bug Fixes> section.

[ List each security issue as a =head2 entry ]

=head1 Incompatible Changes

XXX For a release on a stable branch, this section aspires to be:

    There are no changes intentionally incompatible with 5.XXX.XXX
    If any exist, they are bugs, and we request that you submit a
    report.  See L</Reporting Bugs> below.

[ List each incompatible change as a =head2 entry ]

=head2 C<(?[...])> operators now follow standard Perl precedence

This experimental feature allows set operations in regular expression
patterns.  Prior to this, the intersection operator had the same
precedence as the other binary operators.  Now it has higher precedence.
This could lead to different outcomes than existing code expects (though
the documentation has always noted that this change might happen,
recommending fully parenthesizing the expressions).  See
L<perlrecharclass/Extended Bracketed Character Classes>.

=head1 Deprecations

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

=head2 Module removals

XXX Remove this section if inapplicable.

The following modules will be removed from the core distribution in a
future release, and will at that time need to be installed from CPAN.
Distributions on CPAN which require these modules will need to list them as
prerequisites.

The core versions of these modules will now issue C<"deprecated">-category
warnings to alert you to this fact.  To silence these deprecation warnings,
install the modules in question from CPAN.

Note that these are (with rare exceptions) fine modules that you are encouraged
to continue to use.  Their disinclusion from core primarily hinges on their
necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
not usually on concerns over their design.

=over

=item XXX

XXX Note that deprecated modules should be listed here even if they are listed
as an updated module in the L</Modules and Pragmata> section.

=back

[ 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 *

The functions
C<utf8::native_to_unicode()> and
C<utf8::unicode_to_native()> (see L<utf8>)
are now optimized out on ASCII platforms.
There is now not even a minimal performance hit in writing code portable
between ASCII and EBCDIC platforms.

=back

=head1 Modules and Pragmata

XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
go here.  If Module::CoreList is updated, generate an initial draft of the
following sections using F<Porting/corelist-perldelta.pl>.  A paragraph summary
for important changes should then be added by hand.  In an ideal world,
dual-life modules would have a F<Changes> file that could be cribbed.

[ Within each section, list entries as a =item entry ]

=head2 New Modules and Pragmata

=over 4

=item *

XXX

=back

=head2 Updated Modules and Pragmata

=over 4

=item *

L<B> has been upgraded from version 1.56 to 1.57.

=item *

L<B::Deparse> has been upgraded from version 1.33 to 1.34.

Deparse C<$#_> as that instead of as C<$#{_}>.  [perl #123947]

=item *

L<Carp> has been upgraded from version 1.35 to 1.36.

=item *

L<CPAN> has been upgraded from version 2.05 to 2.10.

=over 4

=item *

Add support for C<Cwd::getdcwd()> and introduce workaround for a misbehaviour
seen on Strawberry Perl 5.20.1.

=item *

Fix C<chdir()> after building dependencies bug.

=item *

Introduce experimental support for plugins/hooks.

=item *

Integrate the App::Cpan sources.

=item *

Do not check recursion on optional dependencies.

=item *

Sanity check META.yml to contain a hash.
L<[cpan #95271]|https://rt.cpan.org/Ticket/Display.html?id=95271>

=back

=item *

L<CPAN::Meta> has been upgraded from version 2.143240 to 2.150001.

=item *

L<Data::Dumper> has been upgraded from version 2.157 to 2.158.

=item *

L<Devel::PPPort> has been upgraded from version 3.28 to 3.31.

=item *

L<DynaLoader> has been upgraded from version 1.31 to 1.32.

=item *

L<Encode> has been upgraded from version 2.70 to 2.72.

=item *

L<encoding> has been upgraded from version 2.13 to 2.14.

=item *

L<Getopt::Long> has been upgraded from version 2.43 to 2.45.

=item *

L<locale> has been upgraded from version 1.05 to 1.06.

=item *

L<Locale::Codes> has been upgraded from version 3.33 to 3.34.

=item *

L<Module::CoreList> has been reverted from version 5.20150220 to 5.20150320.

=item *

L<parent> has been upgraded from version 0.228 to 0.232.

No changes to installed files other than the version bump.

=item *

L<Pod::Functions> has been upgraded from version 1.08 to 1.09.

=item *

L<POSIX> has been upgraded from version 1.51 to 1.52.

=item *

L<re> has been upgraded from version 0.31 to 0.32.

=item *

L<Test::Simple> has been reverted from version 1.301001_098 to 1.001014.

=item *

L<Text::Balanced> has been upgraded from version 2.02 to 2.03.

No changes to installed files other than the version bump.

=item *

L<Text::ParseWords> has been upgraded from version 3.29 to 3.30.

=item *

L<threads> has been upgraded from version 1.96_001 to 2.01.

=item *

L<Unicode::Collate> has been upgraded from version 1.11 to 1.12.

=item *

L<utf8> has been upgraded from version 1.14 to 1.15.

=item *

L<XS::APItest> has been upgraded from version 0.70 to 0.71.

=back

=head2 Removed Modules and Pragmata

=over 4

=item *

XXX

=back

=head1 Documentation

XXX Changes to files in F<pod/> go here.  Consider grouping entries by
file and be sure to link to the appropriate page, e.g. L<perlfunc>.

=head2 New Documentation

XXX Changes which create B<new> files in F<pod/> go here.

=head3 L<XXX>

XXX Description of the purpose of the new file here

=head2 Changes to Existing Documentation

XXX Changes which significantly change existing files in F<pod/> go here.
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.

=head3 L<perldata>

=over 4

=item *

Documentation has been added regarding the special floating point values C<Inf>
and C<NaN>.

=back

=head3 L<perlexperiment>

=over 4

=item *

Removed note about C<\s> matching C<VT> now that it is no longer experimental.

=item *

Added note that C<use re 'strict'> has been introduced experimentally.

=back

=head3 L<perlpolicy>

=over 4

=item *

The documentation of what to expect to see in future maintenance releases has
been updated.  Essentially the same types of changes will be included as before
but with fewer changes that don't affect the installation or execution of perl.

=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 *

L<Invalid quantifier in {,} in regex; marked by <-- HERE in mE<sol>%sE<sol>|perldiag/"Invalid quantifier in {,} in regex; marked by <-- HERE in m/%s/">

(F) The pattern looks like a {min,max} quantifier, but the min or max could not
be parsed as a valid number - either it has leading zeroes, or it represents
too big a number to cope with.  The S<<-- HERE> shows where in the regular
expression the problem was discovered.  See L<perlre>.

=back

=head3 New Warnings

=over 4

=item *

XXX L<message|perldiag/"message">

=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 Utility Changes

XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
Most of these are built within the directory F<utils>.

[ List utility changes as a =head2 entry for each utility and =item
entries for each change
Use L<XXX> with program names to get proper documentation linking. ]

=head2 L<XXX>

=over 4

=item *

XXX

=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 *

XXX

=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 *

Tests for performance issues have been added in the file F<t/perf/taint.t>.

=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 New Platforms

XXX List any platforms that this version of perl compiles on, that previous
versions did not.  These will either be enabled by new files in the F<hints/>
directories, or new subdirectories and F<README> files at the top level of the
source tree.

=over 4

=item z/OS running EBCDIC Code Page 1047

Core perl now works on this EBCDIC platform.  Early perls also worked,
but, even though support wasn't officially withdrawn, recent perls would
not compile and run well.  Perl v5.20 would work, but had many bugs
which have now been fixed.  Many CPAN modules that ship with Perl still
fail tests, including Pod::Simple.  However the version of Pod::Simple
currently on CPAN should work; it was fixed too late to include in
Perl v5.22.  Work is under way to fix many of the still-broken CPAN
modules, which likely will be installed on CPAN when completed, so that
you may not have to wait until v5.24 to get a working version.

=back

=head2 Discontinued Platforms

XXX List any platforms that this version of perl no longer compiles on.

=over 4

=item XXX-some-platform

XXX

=back

=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 *

Macros have been created to allow XS code to better manipulate the POSIX
locale category C<LC_NUMERIC>.
See L<perlapi/Locale-related functions and macros>.

=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 *

Repeated global pattern matches in scalar context on large tainted
strings were exponentially slow depending on the current match
position in the string. [perl #123202]

=item *

Various crashes due to the parser getting confused by syntax errors have
been fixed.  [perl #123801] [perl #123802] [perl #123955] [perl #123995]

=item *

C<split> in the scope of lexical $_ has been fixed not to fail assertions.
[perl #123763]

=item *

C<my $x : attr> syntax inside various list operators no longer fails
assertions.  [perl #123817]

=item *

An @ sign in quotes followed by a non-ASCII digit (which is not a valid
identifier) would cause the parser to crash, instead of simply trying the @
as literal.  This has been fixed.  [perl #123963]

=item *

C<*bar::=*foo::=*glob_with_hash> has been crashing since 5.14, but no
longer does.  [perl #123847]

=item *

C<foreach> in scalar context was not pushing an item on to the stack,
resulting in bugs.  (C<print 4, scalar do { foreach(@x){} } + 1> would
print 5.)  It has been fixed to return C<undef>.  [perl #124004]

=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 *

A goal is for Perl to be able to be recompiled to work reasonably well
on any Unicode version.  In v5.22, though, the earliest such version is
Unicode 5.1 (current is 7.0).

=item *

EBCDIC platforms

=over 4

=item *

Encode and encoding are mostly broken.

=item *

Many cpan modules that are shipped with core show failing tests

=item *

C<pack>/C<unpack> with C<"U0"> format may not work properly.

=back

=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 Obituary

XXX If any significant core contributor has died, we've added a short obituary
here.

=head1 Acknowledgements

XXX Generate this with:

  perl Porting/acknowledgements.pl v5.21.9..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