=head1 NAME
-perldelta - what is new for perl v5.25.10
+[ 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 v5.27.2
=head1 DESCRIPTION
-This document describes differences between the 5.25.9 release and the 5.25.10
+This document describes differences between the 5.27.1 release and the 5.27.2
release.
-If you are upgrading from an earlier release such as 5.25.8, first read
-L<perl5259delta>, which describes differences between 5.25.8 and 5.25.9.
+If you are upgrading from an earlier release such as 5.27.0, first read
+L<perl5271delta>, which describes differences between 5.27.0 and 5.27.1.
-=head1 Modules and Pragmata
+=head1 Notice
-=head2 Updated Modules and Pragmata
+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 ]
+
+=head2 Unicode 10.0 is supported
+
+A list of changes is at
+L<http://www.unicode.org/versions/Unicode10.0.0>.
+
+=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 ]
+
+=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 *
-L<B> has been upgraded from version 1.65 to 1.68.
+XXX
-=item *
+=back
-L<CPAN> has been upgraded from version 2.16 to 2.17.
+=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<feature> has been upgraded from version 1.46 to 1.47.
+[ Within each section, list entries as a =item entry ]
-=item *
+=head2 New Modules and Pragmata
-L<Getopt::Std> has been upgraded from version 1.11 to 1.12.
+=over 4
=item *
-L<Module::CoreList> has been upgraded from version 5.20170120 to 5.20170220.
+XXX
-=item *
+=back
-L<open> has been upgraded from version 1.10 to 1.11.
+=head2 Updated Modules and Pragmata
+
+=over 4
=item *
-L<PerlIO> has been upgraded from version 1.09 to 1.10.
+L<XXX> has been upgraded from version A.xx to B.yy.
-=item *
+=back
+
+=head2 Removed Modules and Pragmata
-L<Storable> has been upgraded from version 2.61 to 2.62.
+=over 4
=item *
-L<Thread::Queue> has been upgraded from version 3.11 to 3.12.
+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
+
+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>.
+
+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.
+
+Additionally, the following selected changes have been made:
+
+=head3 L<XXX>
+
+=over 4
=item *
-L<threads> has been upgraded from version 2.12 to 2.13.
+XXX Description of the change here
=back
including warnings and fatal error messages. For the complete list of
diagnostic messages, see L<perldiag>.
-=head2 Changes to Existing Diagnostics
+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 *
-Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30
+XXX L<message|perldiag/"message">
+
+=back
-This was changed to drop a leading C<v> in C<v5.30>, so it uses the same
-style as other deprecation messages.
+=head3 New Warnings
-=item *
+=over 4
-"\c%c" is more clearly written simply as "%s".
+=item *
-It was decided to undeprecate the use of "\c%c", see L<http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>
+XXX L<message|perldiag/"message">
=back
-=head1 Platform Support
+=head2 Changes to Existing Diagnostics
-=head2 Platform-Specific Notes
+XXX Changes (i.e. rewording) of diagnostic messages go here
=over 4
-=item Windows
+=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 *
-Support for compiling perl on Windows using Microsoft Visual Studio 2015
-(containing Visual C++ 14.0) has been added.
-
-This version of VC++ includes a completely rewritten C run-time library, some
-of the changes in which mean that work done to resolve a socket close() bug in
-perl #120091 and perl #118059 is not workable in its current state with this
-version of VC++. Therefore, we have effectively reverted that bug fix for
-VS2015 onwards on the basis that being able to build with VS2015 onwards is
-more important than keeping the bug fix. We may revisit this in the future to
-attempt to fix the bug again in a way that is compatible with VS2015.
-
-These changes do not affect compilation with GCC or with Visual Studio versions
-up to and including VS2013, i.e. the bug fix is retained (unchanged) for those
-compilers.
-
-Note that you may experience compatibility problems if you mix a perl built
-with GCC or VS E<lt>= VS2013 with XS modules built with VS2015, or if you mix a
-perl built with VS2015 with XS modules built with GCC or VS E<lt>= VS2013.
-Some incompatibility may arise because of the bug fix that has been reverted
-for VS2015 builds of perl, but there may well be incompatibility anyway because
-of the rewritten CRT in VS2015 (e.g. see discussion at
-http://stackoverflow.com/questions/30412951).
+XXX
=back
-=back
+=head1 Configuration and Compilation
-=head1 Internal Changes
+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 *
-The C<op_class()> API function has been added. This is like the existing
-C<OP_CLASS()> macro, but can more accurately determine what struct an op
-has been allocated as. For example C<OP_CLASS()> might return
-C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
-allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
-C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
+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.
+
+XXX If there were no significant test changes, say this:
+
+Tests were added and changed to reflect the other additions and changes
+in this release.
+
+XXX If instead there were significant changes, say this:
+
+Tests were added and changed to reflect the other additions and
+changes in this release. Furthermore, these significant changes were
+made:
+
+[ List each test improvement as a =item entry ]
+
+=over 4
=item *
-The output format of the C<op_dump()> function (as used by C<perl -Dx>)
-has changed: it now displays an "ASCII-art" tree structure, and shows more
-low-level details about each op, such as its address and class.
+XXX
=back
-=head1 Selected Bug Fixes
+=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 *
+=item XXX-some-platform
-Attempting to use the deprecated variable C<$#> as the object in an
-indirect object method call could cause a heap use after free or
-buffer overflow. [perl #129274]
+XXX
-=item *
+=back
-When checking for an indirect object method call in some rare cases
-the parser could reallocate the line buffer but then continue to use
-pointers to the old buffer. [perl #129190]
+=head2 Discontinued Platforms
-=item *
+XXX List any platforms that this version of perl no longer compiles on.
-Supplying a glob as the format argument to L<perlfunc/formline> would
-cause an assertion failure. [perl #130722]
+=over 4
-=item *
+=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.
-Code like C< $value1 =~ qr/.../ ~~ $value2 > would have the match
-converted into a qr// operator, leaving extra elements on the stack to
-confuse any surrounding expression. [perl #130705]
+=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 *
-Since 5.24.0 in some obscure cases, a regex which included code blocks
-from multiple sources (e.g. via embedded via qr// objects) could end up
-with the wrong current pad and crash or give weird results. [perl #129881]
+XXX
+
+=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 *
-Occasionally C<local()>s in a code block within a patterns weren't being
-undone when the pattern matching backtracked over the code block.
-[perl #126697]
+List assignment (C<aassign>) could in some rare cases allocate an
+entry on the mortal stack and leave the entry uninitialized. [perl
+#131570]
=item *
-Using C<substr()> to modify a magic variable could access freed memory
-in some cases. [perl #129340]
+Attempting to apply an attribute to an C<our> variable where a
+function of that name already exists could result in a NULL pointer
+being supplied where an SV was expected, crashing perl. [perl
+#131597]
+
+=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 *
-Perl 5.25.9 was fixed so that under C<use utf8>, the entire Perl program
-is checked that the UTF-8 is wellformed. It turns out that several edge
-cases were missed, and are now fixed. [perl #126310] was the original
-ticket.
+XXX
=back
-=head1 Acknowledgements
+=head1 Errata From Previous Releases
+
+=over 4
-Perl 5.25.10 represents approximately 4 weeks of development since Perl 5.25.9
-and contains approximately 12,000 lines of changes across 200 files from 25
-authors.
+=item *
-Excluding auto-generated files, documentation and release tools, there were
-approximately 6,700 lines of changes to 130 .pm, .t, .c and .h files.
+XXX Add anything here that we forgot to add, or were mistaken about, in
+the perldelta of a previous release.
-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 5.25.10:
+=back
-Aaron Crane, Abigail, Andreas König, Andy Lester, Chris 'BinGOs' Williams,
-Christian Millour, Colin Newell, Dagfinn Ilmari Mannsåker, David Mitchell,
-Hugo van der Sanden, James E Keenan, Jarkko Hietaniemi, Jerry D. Hedden, John
-Lightsey, Karl Williamson, Neil Bowers, Pali, Renee Baecker, Sawyer X, Sergey
-Aleynikov, Steffen Müller, Steve Hay, Tony Cook, Yves Orton, Zefram.
+=head1 Obituary
-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.
+XXX If any significant core contributor has died, we've added a short obituary
+here.
+
+=head1 Acknowledgements
-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.
+XXX Generate this with:
-For a more complete list of all of Perl's historical contributors, please see
-the F<AUTHORS> file in the Perl source distribution.
+ perl Porting/acknowledgements.pl v5.25.5..HEAD
=head1 Reporting Bugs
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
https://perl5.git.perl.org / perl5.git / blobdiff