=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 v5.27.6
=head1 DESCRIPTION
If you are upgrading from an earlier release such as 5.27.4, first read
L<perl5275delta>, which describes differences between 5.27.4 and 5.27.5.
-=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 ]
-
=head2 Initialisation of aggregate state variables
A persistent lexical array or hash variable can now be initialized,
by an expression such as C<state @a = qw(x y z)>. Initialization of a
list of persistent lexical variables is still not possible.
-=head1 Security
+=head2 Full-size inode numbers
-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 ]
+On platforms where inode numbers are of a type larger than perl's native
+integer numerical types, L<stat|perlfunc/stat> will preserve the full
+content of large inode numbers by returning them in the form of strings of
+decimal digits. Exact comparison of inode numbers can thus be achieved by
+comparing with C<eq> rather than C<==>. Comparison with C<==>, and other
+numerical operations (which are usually meaningless on inode numbers),
+work as well as they did before, which is to say they fall back to
+floating point, and ultimately operate on a fairly useless rounded inode
+number if the real inode number is too big for the floating point format.
=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.
+=head2 Yada-yada is now strictly a statement
-[ List each incompatible change as a =head2 entry ]
+By the time of its initial stable release in Perl 5.12, the C<...>
+(yada-yada) operator was explicitly intended to serve as a statement,
+not an expression. However, the original implementation was confused
+on this point, leading to inconsistent parsing. The operator was
+accidentally accepted in a few situations where it did not serve as a
+complete statement, such as
-=head1 Deprecations
+ ... . "foo";
+ ... if $a < $b;
-XXX Any deprecated features, syntax, modules etc. should be listed here.
+The parsing has now been made consistent, permitting yada-yada only as
+a statement. Affected code can use C<do{...}> to put a yada-yada into
+an arbitrary expression context.
-=head2 Module removals
+=head2 Subroutines no longer need typeglobs
-XXX Remove this section if inapplicable.
+Perl 5.22.0 introduced an optimization allowing subroutines to be stored in
+packages as simple sub refs, not requiring a full typeglob (thus
+potentially saving large amounts of memeory). However, the optimization
+was flawed: it only applied to the main package.
-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.
+This optimization has now been extended to all packages. This may break
+compatibility with introspection code that looks inside stashes and expects
+everything in them to be a typeglob.
-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.
+When this optimization happens, the typeglob still notionally exists, so
+accessing it will cause the stash entry to be upgraded to a typeglob. The
+optimization does not apply to XSUBs or exported subroutines, and calling a
+method will undo it, since method calls cache things in typeglobs.
-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.
+(This change actually happened in perl 5.27.5 but was omitted from its perldelta.)
-=over
+[perl #129916] [perl #132252]
-=item XXX
+=head2 Sort algorithm can no longer be specified
-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 ]
+Since Perl 5.8, the L<sort> pragma has had subpragmata C<_mergesort>,
+C<_quicksort>, and C<_qsort> that can be used to specify which algorithm
+perl should use to implement the L<sort|perlfunc/sort> builtin.
+This was always considered a dubious feature that might not last,
+hence the underscore spellings, and they were documented as not being
+portable beyond Perl 5.8. These subpragmata have now been deleted,
+and any attempt to use them is an error. The L<sort> pragma otherwise
+remains, and the algorithm-neutral C<stable> subpragma can be used to
+control sorting behaviour.
+[perl #119635]
=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 an =item entry ]
-
=over 4
=item *
$s .= "a=$a b=$b\n"
-As a special case, if the LHS of an assign is a lexical variable or
+As a special case, if the LHS of an assignment is a lexical variable or
C<my $s>, the op itself handles retrieving the lexical variable, which
is faster.
containing only C<%s> and C<%%> format elements, and which have a fixed
number of arguments, are now also optimised into a C<multiconcat> op.
+=item *
+
+Subroutines in packages no longer need to be stored in typeglobs, saving
+large amounts of memory. See L</Subroutines no longer need typeglobs>
+under L</Incompatible Changes>, above.
+
=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.
+Key highlights in this release across several modules:
+
+=head2 Removal of use vars
+
+The usage of C<use vars> has been discouraged since the introduction of C<our> in
+Perl 5.6.0. Where possible the usage of this pragma has now been removed from
+the Perl source code.
-The list of new and updated modules is modified automatically as part of
-preparing a Perl release, so the only reason to manually add entries here is if
-you're summarising the important changes in the module update. (Also, if the
-manually-added details don't match the automatically-generated ones, the
-release manager will have to investigate the situation carefully.)
+This had a slight effect (for the better) on the output of WARNING_BITS in B::Deparse.
-[ Within each section, list entries as an =item entry ]
+=head2 Use of DynaLoader changed to XSLoader in many modules
-=head2 New Modules and Pragmata
+XSLoader is more modern, and most modules already require perl 5.6 or greater, so
+no functionality is lost by switching. In some cases, we have also made changes to
+the local implementation that may not be reflected in the version on CPAN due
+to a desire to maintain more backwards compatibility.
+
+=head2 Updated Modules and Pragmata
=over 4
=item *
-XXX
+L<Attribute::Handlers> has been upgraded from version 1.00 to 1.01.
-=back
+=item *
-=head2 Updated Modules and Pragmata
+L<attributes> has been upgraded from version 0.31 to 0.32.
-=over 4
+=item *
+
+L<B> has been upgraded from version 1.70 to 1.72.
+
+=item *
+
+L<B::Concise> has been upgraded from version 1.002 to 1.003.
+
+=item *
+
+L<B::Deparse> has been upgraded from version 1.43 to 1.45.
+
+=item *
+
+L<base> has been upgraded from version 2.26 to 2.27.
+
+=item *
+
+L<blib> has been upgraded from version 1.06 to 1.07.
=item *
=item *
+L<Compress::Raw::Zlib> has been upgraded from version 2.074 to 2.075.
+
+This addresses a security vulnerability in older versions of the 'zlib' library
+(which is bundled with Compress-Raw-Zlib).
+
+=item *
+
+L<Config::Extensions> has been upgraded from version 0.01 to 0.02.
+
+=item *
+
+L<Devel::PPPort> has moved from cpan-first to perl-first maintenance
+
+Primary responsibility for the code in Devel::PPPort has moved into core perl.
+In a practical sense there should be no change except that hopefully it will
+stay more up to date with changes made to symbols in perl, rather than needing
+to be updated after the fact.
+
+=item *
+
+L<DynaLoader> has been upgraded from version 1.42 to 1.44.
+
+=item *
+
+L<experimental> has been upgraded from version 0.016 to 0.017.
+
+=item *
+
+L<ExtUtils::CBuilder> has been upgraded from version 0.280228 to 0.280229.
+
+=item *
+
+L<ExtUtils::Embed> has been upgraded from version 1.34 to 1.35.
+
+=item *
+
+L<ExtUtils::Miniperl> has been upgraded from version 1.06 to 1.07.
+
+=item *
+
+L<ExtUtils::ParseXS> has been upgraded from version 3.35 to 3.36.
+
+=item *
+
+L<ExtUtils::Typemaps> has been upgraded from version 3.35 to 3.36.
+
+=item *
+
+L<ExtUtils::XSSymSet> has been upgraded from version 1.3 to 1.4.
+
+=item *
+
+L<fields> has been upgraded from version 2.23 to 2.24.
+
+=item *
+
L<File::Copy> has been upgraded from version 2.32 to 2.33. It will now use
-Time::HiRes utime where available (RT #132401).
+Time::HiRes utime where available (perl #132401).
-=back
+=item *
-=head2 Removed Modules and Pragmata
+L<File::Spec> has been upgraded from version 3.68 to 3.70.
-=over 4
+=item *
+
+L<File::stat> has been upgraded from version 1.07 to 1.08.
=item *
-XXX
+L<FileCache> has been upgraded from version 1.09 to 1.10.
-=back
+=item *
-=head1 Documentation
+L<Filter::Simple> has been upgraded from version 0.94 to 0.95.
+
+=item *
+
+L<Hash::Util::FieldHash> has been upgraded from version 1.19 to 1.20.
+
+=item *
+
+L<I18N::Langinfo> has been upgraded from version 0.14 to 0.15.
+
+=item *
+
+L<I18N::LangTags> has been upgraded from version 0.42 to 0.43.
+
+=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>.
+The libnet distribution has been upgraded from version 3.10 to 3.11.
-=head2 New Documentation
+=item *
+
+L<Locale::Maketext> has been upgraded from version 1.28 to 1.29.
-XXX Changes which create B<new> files in F<pod/> go here.
+=item *
-=head3 L<XXX>
+L<Module::CoreList> has been upgraded from version 5.20171020 to 5.20171120.
-XXX Description of the purpose of the new file here
+=item *
+
+L<Net::Ping> has been upgraded from version 2.55 to 2.62.
+
+=item *
+
+L<ODBM_File> has been upgraded from version 1.14 to 1.15.
+
+=item *
+
+L<Opcode> has been upgraded from version 1.40 to 1.41.
+
+=item *
+
+L<Pod::Html> has been upgraded from version 1.2202 to 1.2203.
+
+=item *
+
+L<POSIX> has been upgraded from version 1.78 to 1.80.
+
+=item *
+
+L<re> has been upgraded from version 0.35 to 0.36.
+
+=item *
+
+L<SelfLoader> has been upgraded from version 1.24 to 1.25.
+
+=item *
+
+L<Socket> has been upgraded from version 2.020_03 to 2.020_04.
+
+=item *
+
+L<sort> has been upgraded from version 2.03 to 2.04.
+
+=item *
+
+L<Storable> has been upgraded from version 2.64 to 2.65.
+
+=item *
+
+L<Test> has been upgraded from version 1.30 to 1.31.
+
+=item *
+
+L<Test::Simple> has been upgraded from version 1.302103 to 1.302111.
+
+=item *
+
+L<threads> has been upgraded from version 2.18 to 2.19.
+
+=item *
+
+L<Tie::Array> has been upgraded from version 1.06 to 1.07.
+
+=item *
+
+L<Tie::StdHandle> has been upgraded from version 4.4 to 4.5.
+
+=item *
+
+L<Time::gmtime> has been upgraded from version 1.03 to 1.04.
+
+=item *
+
+L<Time::HiRes> has been upgraded from version 1.9746 to 1.9747.
+
+=item *
+
+L<Time::localtime> has been upgraded from version 1.02 to 1.03.
+
+=item *
+
+L<Unicode::Collate> has been upgraded from version 1.19 to 1.23.
+
+=item *
+
+L<Unicode::Normalize> has been upgraded from version 1.25 to 1.26.
+
+=item *
+
+L<User::grent> has been upgraded from version 1.01 to 1.02.
+
+=item *
+
+L<User::pwent> has been upgraded from version 1.00 to 1.01.
+
+=item *
+
+L<VMS::DCLsym> has been upgraded from version 1.08 to 1.09.
+
+=item *
+
+L<VMS::Stdio> has been upgraded from version 2.42 to 2.44.
+
+=item *
+
+L<warnings> has been upgraded from version 1.37 to 1.38.
+
+=item *
+
+L<XS::Typemap> has been upgraded from version 0.15 to 0.16.
+
+=item *
+
+L<XSLoader> has been upgraded from version 0.27 to 0.28.
+
+=back
+
+=head1 Documentation
=head2 Changes to Existing Documentation
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<perldiag/Variable length lookbehind not implemented in regex m/%s/>
+=over 4
+
+=item * L<perldiag/Variable length lookbehind not implemented in regex m/%s/>
This now gives more ideas as to workarounds to the issue that was
introduced in Perl 5.18 (but not documented explicitly in its perldelta)
to be considered variable length, and hence disallowed.
-=over 4
-
-=item *
+=item * "Use of state $_ is experimental" in L<perldiag>
-XXX Description of the change here
+This entry has been removed, as the experimental support of this construct was
+removed in perl 5.24.0.
-=back
+=item *
-=head1 Diagnostics
+The section on reference counting in L<perlguts> has been heavily revised,
+to describe references in the way a programmer needs to think about them
+rather than in terms of the physical data structures.
-The following additions or changes have been made to diagnostic output,
-including warnings and fatal error messages. For the complete list of
-diagnostic messages, see L<perldiag>.
+=item *
-XXX New or changed warnings emitted by the core's C<C> code go here. Also
-include any changes in L<perldiag> that reconcile it to the C<C> code.
+The section "Truth and Falsehood" in L<perlsyn> has been removed from
+that document, where it didn't belong, and merged into the existing
+paragraph on the same topic in L<perldata>.
-=head2 New Diagnostics
+=item *
-XXX Newly added diagnostic messages go under here, separated into New Errors
-and New Warnings
+The description of the C<x> operator in L<perlop> has been clarified. [perl #132460]
-=head3 New Errors
+=item *
-=over 4
+L<perluniprops> has been updated to note that C<\p{Word}> now includes
+code points matching the C<\p{Join_Control}> property. The change to
+the property was made in Perl 5.18, but not documented until now. There
+are currently only two code points that match this property U+200C (ZERO
+WIDTH NON-JOINER) and U+200D (ZERO WIDTH JOINER).
=item *
-XXX L<message|perldiag/"message">
-
-=back
+The entry for C<$+> in perlvar has been expanded upon to describe handling of
+multiply-named capturing groups.
-=head3 New Warnings
+=item *
-=over 4
+L<perlop> has been updated to note that C<qw>'s whitespace rules differ from that of
+C<split>'s in that only ASCII whitespace is used.
=item *
-XXX L<message|perldiag/"message">
+L<POSIX> has been updated with some more cautions about using locale-specific
+functions in threaded applications.
=back
-=head2 Changes to Existing Diagnostics
+=head1 Diagnostics
-XXX Changes (i.e. rewording) of diagnostic messages go here
+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>.
+
+=head2 Changes to Existing Diagnostics
=over 4
in list currently forbidden>, because list-context initialization of
single aggregate state variables is now permitted.
-=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>
+=head2 L<perlbug>
=over 4
=item *
-XXX
+C<--help> and C<--version> options have been added.
=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.
+=over 4
-[ List changes as an =item entry ].
+=item C89 requirement
-=over 4
+Perl has been documented as requiring a C89 compiler to build since October
+1998. A variety of simplifications have now been made to Perl's internals to
+rely on the features specified by the C89 standard. We believe that this
+internal change hasn't altered the set of platforms that Perl builds on, but
+please report a bug if Perl now has new problems building on your platform.
=item New probes
=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:
+=head1 Packaging
-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 an =item entry ]
-
-=over 4
-
-=item *
-
-XXX
-
-=back
+For the past few years we have released perl using three different archive
+formats: bzip (C<.bz2>), LZMA2 (C<.xz>) and gzip (C<.gz>). Since xz compresses
+better and decompresses faster, and gzip is more compatible and uses less memory,
+we have dropped the C<.bz2> archive format with this release.
+(If this poses a problem, do let us know; see L</Reporting Bugs>, below.)
=head1 Platform Support
-XXX Any changes to platform support should be listed in the sections below.
-
-[ Within the sections, list each platform as an =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 XXX-some-platform
-
-XXX
-
-=back
-
=head2 Discontinued Platforms
-XXX List any platforms that this version of perl no longer compiles on.
-
=over 4
-=item XXX-some-platform
+=item PowerUX / Power MAX OS
-XXX
+Compiler hints and other support for these apparently long-defunct platforms has been removed.
=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
+=item Windows
-XXX
+Visual C++ compiler version detection has been improved to work on non-English
+language systems.
=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 an =item entry ]
-
=over 4
=item *
representation changes under utf8, two sets of strings plus lengths are
precomputed and stored.
-=back
+=item *
-=head1 Selected Bug Fixes
+Direct access to L<C<PL_keyword_plugin>|perlapi/PL_keyword_plugin> is not
+safe in the presence of multithreading. A new
+L<C<wrap_keyword_plugin>|perlapi/wrap_keyword_plugin> function has been
+added to allow XS modules to safely define custom keywords even when
+loaded from a thread, analogous to L<C<PL_check>|perlapi/PL_check> /
+L<C<wrap_op_checker>|perlapi/wrap_op_checker>.
-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>.
+=back
-[ List each fix as an =item entry ]
+=head1 Selected Bug Fixes
=over 4
=item *
+C<stat()>, C<lstat()>, and file test operators now reliably set C<$!> when
+failing due to being applied to a closed or otherwise invalid file handle.
+
+=item *
+
+File test operators for Unix permission bits that don't exist on a
+particular platform, such as C<-k> (sticky bit) on Windows, now check that
+the file being tested exists before returning the blanket false result,
+and yield the appropriate errors if the argument doesn't refer to a file.
+
+=item *
+
The in-place reverse optimisation now correctly strengthens weak
references using the L<C<sv_rvunweaken()>|perlapi/sv_rvunweaken>
API function.
Fixed a leaked SV when parsing an empty C<\N{}> at compile-time.
[perl #132245]
-=back
-
-=head1 Known Problems
+=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.
+Calling C<do $path> on a directory or block device now yields a meaningful
+error code in C<$!>. [perl #125774]
-[ List each fix as an =item entry ]
+=item *
-=over 4
+Regexp substitution using an overloaded replacement value that provides
+a tainted stringification now correctly taints the resulting string.
+[perl #115266]
=item *
-XXX
+Lexical sub declarations in C<do> blocks such as C<do { my sub lex; 123 }>
+could corrupt the stack, erasing items already on the stack in the
+enclosing statement. This has been fixed. [perl #132442]
=back
=item *
-XXX Add anything here that we forgot to add, or were mistaken about, in
-the perldelta of a previous release.
+L</Subroutines no longer need typeglobs> under L</Incompatible Changes>, above,
+was made for perl 5.27.5 but was mistakenly omitted from its perldelta.
=back
-=head1 Obituary
-
-XXX If any significant core contributor has died, we've added a short obituary
-here.
-
=head1 Acknowledgements
XXX Generate this with:
https://perl5.git.perl.org / perl5.git / blobdiff