=head1 NAME
-perldelta - what is new for perl v5.21.10
+[ 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 v5.21.12
=head1 DESCRIPTION
-This document describes differences between the 5.21.9 release and the 5.21.10
+This document describes differences between the 5.21.11 release and the 5.21.12
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.
+If you are upgrading from an earlier release such as 5.21.10, first read
+L<perl52111delta>, which describes differences between 5.21.10 and 5.21.11.
-=head1 Incompatible Changes
+=head1 Notice
-=head2 C<(?[...])> operators now follow standard Perl precedence
+XXX Any important notices here
-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 Core Enhancements
-=head1 Performance 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.
-=over 4
+[ List each enhancement as a =head2 entry ]
-=item *
+=head1 Security
-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.
+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.
-=back
-
-=head1 Modules and Pragmata
+[ List each security issue as a =head2 entry ]
-=head2 Updated Modules and Pragmata
-
-=over 4
-
-=item *
+=head1 Incompatible Changes
-L<B> has been upgraded from version 1.56 to 1.57.
+XXX For a release on a stable branch, this section aspires to be:
-=item *
+ 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.
-L<B::Deparse> has been upgraded from version 1.33 to 1.34.
+[ List each incompatible change as a =head2 entry ]
-Deparse C<$#_> as that instead of as C<$#{_}>.
-L<[perl #123947]|https://rt.perl.org/Ticket/Display.html?id=123947>
+=head1 Deprecations
-=item *
+XXX Any deprecated features, syntax, modules etc. should be listed here.
-L<Carp> has been upgraded from version 1.35 to 1.36.
+=head2 Module removals
-=item *
+XXX Remove this section if inapplicable.
-L<CPAN> has been upgraded from version 2.05 to 2.10.
+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.
-=over 4
+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.
-=item *
+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.
-Add support for C<Cwd::getdcwd()> and introduce workaround for a misbehaviour
-seen on Strawberry Perl 5.20.1.
+=over
-=item *
+=item XXX
-Fix C<chdir()> after building dependencies bug.
+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.
-=item *
+=back
-Introduce experimental support for plugins/hooks.
+[ List each other deprecation as a =head2 entry ]
-=item *
+=head1 Performance Enhancements
-Integrate the App::Cpan sources.
+XXX Changes which enhance performance without changing behaviour go here.
+There may well be none in a stable release.
-=item *
+[ List each enhancement as a =item entry ]
-Do not check recursion on optional dependencies.
+=over 4
=item *
-Sanity check META.yml to contain a hash.
-L<[cpan #95271]|https://rt.cpan.org/Ticket/Display.html?id=95271>
+XXX
=back
-=item *
-
-L<CPAN::Meta> has been upgraded from version 2.143240 to 2.150001.
+=head1 Modules and Pragmata
-=item *
+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.
-L<Data::Dumper> has been upgraded from version 2.157 to 2.158.
+[ Within each section, list entries as a =item entry ]
-=item *
+=head2 New Modules and Pragmata
-L<DB> has been upgraded from version 1.07 to 1.08.
+=over 4
=item *
-L<Devel::PPPort> has been upgraded from version 3.28 to 3.31.
-
-=item *
+XXX
-L<DynaLoader> has been upgraded from version 1.31 to 1.32.
+=back
-=item *
+=head2 Updated Modules and Pragmata
-L<Encode> has been upgraded from version 2.70 to 2.72.
+=over 4
=item *
-L<encoding> has been upgraded from version 2.13 to 2.14.
+L<Module::CoreList> has been upgraded from version 5.20150420 to 5.20150520.
-=item *
+Updated to cover the latest releases of Perl.
-L<Getopt::Long> has been upgraded from version 2.43 to 2.45.
+=back
-=item *
+=head2 Removed Modules and Pragmata
-L<locale> has been upgraded from version 1.05 to 1.06.
+=over 4
=item *
-L<Locale::Codes> has been upgraded from version 3.33 to 3.34.
+XXX
-=item *
+=back
-L<Module::CoreList> has been upgraded from version 5.20150220 to 5.20150320.
+=head1 Documentation
-=item *
+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>.
-L<parent> has been upgraded from version 0.228 to 0.232.
+=head2 New Documentation
-No changes to installed files other than the version bump.
+XXX Changes which create B<new> files in F<pod/> go here.
-=item *
+=head3 L<XXX>
-The PathTools modules have been upgraded from version 3.54 to 3.55.
+XXX Description of the purpose of the new file here
-=item *
+=head2 Changes to Existing Documentation
-L<Pod::Functions> has been upgraded from version 1.08 to 1.09.
+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.
-=item *
+=head3 L<XXX>
-L<POSIX> has been upgraded from version 1.51 to 1.52.
+=over 4
=item *
-L<re> has been upgraded from version 0.31 to 0.32.
+XXX Description of the change here
-=item *
-
-L<sigtrap> has been upgraded from version 1.07 to 1.08.
+=back
-=item *
+=head1 Diagnostics
-L<Term::Complete> has been upgraded from version 1.402 to 1.403.
+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>.
-=item *
+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.
-L<Test::Simple> has been reverted from version 1.301001_098 to 1.001014.
+=head2 New Diagnostics
-=item *
+XXX Newly added diagnostic messages go under here, separated into New Errors
+and New Warnings
-L<Text::Balanced> has been upgraded from version 2.02 to 2.03.
+=head3 New Errors
-No changes to installed files other than the version bump.
+=over 4
=item *
-L<Text::ParseWords> has been upgraded from version 3.29 to 3.30.
+XXX L<message|perldiag/"message">
-=item *
-
-L<threads> has been upgraded from version 1.96_001 to 2.01.
+=back
-=item *
+=head3 New Warnings
-L<Unicode::Collate> has been upgraded from version 1.11 to 1.12.
+=over 4
=item *
-L<utf8> has been upgraded from version 1.14 to 1.15.
+XXX L<message|perldiag/"message">
=back
-=head1 Documentation
+=head2 Changes to Existing Diagnostics
-=head2 Changes to Existing Documentation
-
-=head3 L<perldata>
+XXX Changes (i.e. rewording) of diagnostic messages go here
=over 4
=item *
-Documentation has been added regarding the special floating point values C<Inf>
-and C<NaN>.
+XXX Describe change here
=back
-=head3 L<perlexperiment>
+=head1 Utility Changes
-=over 4
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
+Most of these are built within the directory F<utils>.
-=item *
-
-Removed note about C<\s> matching C<VT> now that it is no longer experimental.
-
-=item *
+[ 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. ]
-Added note that C<use re 'strict'> has been introduced experimentally.
-
-=back
-
-=head3 L<perlpolicy>
+=head2 L<XXX>
=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.
+XXX
=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>.
+=head1 Configuration and Compilation
-=head2 New Diagnostics
+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.
-=head3 New Errors
+[ List changes as a =item entry ].
=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>.
+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>.
+XXX
=back
=head1 Platform Support
-=head2 New Platforms
-
-=over 4
-
-=item z/OS running EBCDIC Code Page 1047
+XXX Any changes to platform support should be listed in the sections below.
-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 5.20 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 5.22. 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 Perl 5.24 to get a working
-version.
+[ Within the sections, list each platform as a =item entry with specific
+changes as paragraphs below it. ]
-=back
+=head2 New Platforms
-=head2 Platform-Specific Notes
+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 HP-UX
+=item XXX-some-platform
-The archname now distinguishes use64bitint from use64bitall.
+XXX
=back
-=head1 Internal Changes
-
-=over 4
+=head2 Discontinued Platforms
-=item *
+XXX List any platforms that this version of perl no longer compiles on.
-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>.
+=over 4
-=item *
+=item XXX-some-platform
-The previous C<atoi> et al replacement function, C<grok_atou>, has now been
-superseded by C<grok_atoUV>. See L<perlclib> for details.
+XXX
=back
-=head1 Selected Bug Fixes
+=head2 Platform-Specific Notes
-=over 4
+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.
-=item *
-
-Repeated global pattern matches in scalar context on large tainted strings were
-exponentially slow depending on the current match position in the string.
-L<[perl #123202]|https://rt.perl.org/Ticket/Display.html?id=123202>
+=over 4
-=item *
+=item XXX-some-platform
-Various crashes due to the parser getting confused by syntax errors have been
-fixed.
-L<[perl #123801]|https://rt.perl.org/Ticket/Display.html?id=123801>
-L<[perl #123802]|https://rt.perl.org/Ticket/Display.html?id=123802>
-L<[perl #123955]|https://rt.perl.org/Ticket/Display.html?id=123955>
-L<[perl #123995]|https://rt.perl.org/Ticket/Display.html?id=123995>
+XXX
-=item *
-
-C<split> in the scope of lexical $_ has been fixed not to fail assertions.
-L<[perl #123763]|https://rt.perl.org/Ticket/Display.html?id=123763>
+=back
-=item *
+=head1 Internal Changes
-C<my $x : attr> syntax inside various list operators no longer fails
-assertions.
-L<[perl #123817]|https://rt.perl.org/Ticket/Display.html?id=123817>
+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.
-=item *
+[ List each change as a =item entry ]
-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.
-L<[perl #123963]|https://rt.perl.org/Ticket/Display.html?id=123963>
+=over 4
=item *
-C<*bar::=*foo::=*glob_with_hash> has been crashing since Perl 5.14, but no
-longer does.
-L<[perl #123847]|https://rt.perl.org/Ticket/Display.html?id=123847>
-
-=item *
+XXX
-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>.
-L<[perl #124004]|https://rt.perl.org/Ticket/Display.html?id=124004>
+=back
-=item *
+=head1 Selected Bug Fixes
-A memory leak introduced in Perl 5.21.6 has been fixed.
-L<[perl #123922]|https://rt.perl.org/Ticket/Display.html?id=123922>
+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>.
-=item *
+[ List each fix as a =item entry ]
-A regression in the behaviour of the C<readline> built-in function, caused by
-the introduction of the C<< <<>> >> operator, has been fixed.
-L<[perl #123990]|https://rt.perl.org/Ticket/Display.html?id=123990>
+=over 4
=item *
-Several cases of data used to store environment variable contents in core C
-code being potentially overwritten before being used have been fixed.
-L<[perl #123748]|https://rt.perl.org/Ticket/Display.html?id=123748>
+XXX
=back
=head1 Known Problems
-=over 4
-
-=item *
+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.
-A goal is for Perl to be able to be recompiled to work reasonably well on any
-Unicode version. In Perl 5.22, though, the earliest such version is Unicode
-5.1 (current is 7.0).
-
-=item *
-
-EBCDIC platforms
+[ List each fix as a =item entry ]
=over 4
=item *
-Encode and encoding are mostly broken.
+XXX
-=item *
+=back
-Many cpan modules that are shipped with core show failing tests.
+=head1 Errata From Previous Releases
+
+=over 4
=item *
-C<pack>/C<unpack> with C<"U0"> format may not work properly.
+XXX Add anything here that we forgot to add, or were mistaken about, in
+the perldelta of a previous release.
=back
-=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
+ perl Porting/acknowledgements.pl v5.21.11..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.
+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