[ 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 v5.31.1
+perldelta - what is new for perl v5.31.5
=head1 DESCRIPTION
-This document describes differences between the 5.31.0 release and the 5.31.1
+This document describes differences between the 5.31.4 release and the 5.31.5
release.
-If you are upgrading from an earlier release such as 5.30.0, first read
-L<perl5310delta>, which describes differences between 5.30.0 and 5.31.0.
+If you are upgrading from an earlier release such as 5.31.3, first read
+L<perl5314delta>, which describes differences between 5.31.3 and 5.31.4.
+
+=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
-=head2 Use of L<C<vec>|perlfunc/vec EXPR,OFFSET,BITS> on strings with code points above 0xFF is forbidden
+XXX For a release on a stable branch, this section aspires to be:
-Such strings are represented internally in UTF-8, and C<vec> is a
-bit-oriented operation that will likely give unexpected results on those
-strings. This was deprecated in perl 5.28.0.
+ 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 Use of code points over 0xFF in string bitwise operators
+[ List each incompatible change as a =head2 entry ]
-Some uses of these were already illegal after a previous deprecation
-cycle. The remaining uses are now prohibited, having been deprecated in perl
-5.28.0. See L<perldeprecation>.
+=head2 Modifiable variables are no longer permitted in constants
-=head2 C<Sys::Hostname::hostname()> does not accept arguments
+Code like:
-This usage was deprecated in perl 5.28.0 and is now fatal.
+ my $var;
+ $sub = sub () { $var };
-=head1 Modules and Pragmata
+where C<$var> is referenced elsewhere in some sort of modiable context
+now produces an exception when the sub is defined.
+
+This error can be avoided by adding a return to the sub definition:
+
+ $sub = sub () { return $var };
+
+This has been deprecated since perl 5.22.
+
+[perl #131138]
+
+=head1 Deprecations
+
+XXX Any deprecated features, syntax, modules etc. should be listed here.
+
+=head2 Module removals
+
+XXX Remove this section if not applicable.
-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.
+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 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.)
+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.
-[ Within each section, list entries as an =item entry ]
+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.
-=head2 New Modules and Pragmata
+=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 an =item entry ]
=over 4
=item *
-XXX Remove this section if not applicable.
+XXX
=back
+=head1 Modules and Pragmata
+
=head2 Updated Modules and Pragmata
=over 4
=item *
-L<IO> has been upgraded from version 1.40 to 1.41.
+L<B> has been upgraded from version 1.76 to 1.77.
+
+=item *
-The supplied I<TO> is now always honoured on calls to the send()
-method. [perl #133936]
+L<B::Deparse> has been upgraded from version 1.49 to 1.50.
=item *
-L<Storable> has been upgraded from version 3.15 to 3.16.
+L<Devel::PPPort> has been upgraded from version 3.55 to 3.54.
-Regular expressions objects weren't properly counted for object id
-purposes on retrieve. This would corrupt the resulting structure, or
-cause a runtime error in some cases. [perl #134179]
+=item *
-=back
+L<Digest::MD5> has been upgraded from version 2.55 to 2.55_01.
-=head2 Removed Modules and Pragmata
+=item *
-=over 4
+L<Dumpvalue> has been upgraded from version 1.18 to 1.21.
+
+Previously, when dumping elements of an array and encountering an undefined
+value, the string printed would have been C<empty array>. This has been
+changed to what was apparently originally intended: C<empty slot>.
+
+=item *
+
+L<ExtUtils::CBuilder> has been upgraded from version 0.280232 to 0.280233.
+
+=item *
+
+L<Math::BigInt> has been upgraded from version 1.999816 to 1.999817_01.
+
+=item *
+
+L<Math::BigInt::FastCalc> has been upgraded from version 0.5008 to 0.5009.
=item *
-Pod::Parser has been removed from the core distribution.
-It still is available for download from CPAN. This resolves [perl
-#119439].
+L<Module::CoreList> has been upgraded from version 5.20190920 to 5.20191020.
+
+=item *
+
+L<Safe> has been upgraded from version 2.40 to 2.41.
+
+=item *
+
+L<threads> has been upgraded from version 2.22 to 2.23.
+
+=item *
+
+L<Time::HiRes> has been upgraded from version 1.9763 to 1.9764.
+
+=item *
+
+L<XS::APItest> has been upgraded from version 1.03 to 1.04.
+
+If there was something important to note about this change, include that here.
=back
listed in this document. If you find any we have missed, send email
to L<perlbug@perl.org|mailto:perlbug@perl.org>.
-Additionally, the following selected changes have been made:
-
=head3 L<perlguts>
=over 4
=item *
-Documentation about embed.fnc flags has been removed. F<embed.fnc> now has
-sufficient comments within it. Anyone changing that file will see those
-comments first, so entries here are now redundant.
+Details of the various stacks within the perl interpreter are now explained
+here.
=back
-=head3 L<perlpod>
+Additionally, the following selected changes have been made:
+
+=head3 URLs have been changed to https://, stale links updated
=over 4
=item *
-Advice has been added regarding the usage of C<< Z<> >>.
+Where applicable, the URLs in the documentation have been moved from
+using the http:// protocol to https:// . This also affects the location
+of the bug tracker at L<https://rt.perl.org>.
+
+=item *
+
+Some links to OS/2 libraries, Address Sanitizer and other system tools
+had gone stale. These have been updated with working links.
+
+=item *
+
+Some links to old mails on perl5-porters had gone stale. These have been
+updated with working links.
=back
-=head1 Configuration and Compilation
+=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>.
+
+=head2 Changes to Existing Diagnostics
=over 4
=item *
-F<autodoc.pl>
+L<Can't use global %s in %s|perldiag/"Can't use global %s in %s">
-This tool that regenerates L<perlintern> and L<perlapi> has been overhauled
-significantly, restoring consistency in flags used in F<embed.fnc> and
-L<Devel::PPPort> and allowing removal of many redundant C<=for apidoc>
-entries in code.
+This error message has been slightly reformatted from the original C<Can't use
+global %s in "%s">, and in particular misleading error messages like C<Can't
+use global $_ in "my"> are now rendered as C<Can't use global $_ in subroutine
+signature>.
-=back
+=item *
-=head1 Platform Support
+L<Constants from lexical variables potentially modified elsewhere are no longer permitted|perldiag/"Constants from lexical variables potentially modified elsewhere are no longer permitted">
-=head2 Discontinued Platforms
+This error message replaces the former C<Constants from lexical variables
+potentially modified elsewhere are deprecated. This will not be allowed in Perl
+5.32> to reflect the fact that this previously deprecated usage has now been
+transformed into an exception. The message's classification has also been
+updated from D (deprecated) to F (fatal).
-=over 4
+=back
-=item Windows CE
+=head1 Utility Changes
-Support for building perl on Windows CE has now been removed.
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
+Most of these are built within the directory F<utils>.
-=back
+[ List utility changes as a =head2 entry for each utility and =item
+entries for each change
+Use L<XXX> with program names to get proper documentation linking. ]
-=head1 Internal Changes
+=head2 L<XXX>
=over 4
=item *
-L<eval_pv()|perlapi/eval_pv> no longer stringifies the exception when
-C<croak_on_error> is true. [perl #134175]
+XXX
=back
-=head1 Selected Bug Fixes
+=head1 Configuration and Compilation
+
+XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
+go here. Any other changes to the Perl build process should be listed here.
+However, any platform-specific changes should be listed in the
+L</Platform Support> section, instead.
+
+[ List changes as an =item entry ].
=over 4
=item *
-Setting C<$)> now properly sets supplementary group ids if you have
-the necessary privileges. [perl #134169]
+Perl now no longer probes for C<d_u32align>, defaulting to C<define>
+on all platforms. This check was error prone when it was done, which
+was on 32-bit platforms only. [perl #133495]
=item *
-close() on a pipe now preemptively clears the PerlIO object from the
-IO SV. This prevents a second attempt to close the already closed
-PerlIO object if a signal handler calls die() or exit() while close()
-is waiting for the child process to complete. [perl #122112]
+Documentation and hints for building perl on Z/OS (native EBCDIC) have
+been updated. Still work in progress.
=item *
-C<< sprintf("%.*a", -10000, $x) >> would cause a buffer overflow due
-to mishandling of the negative precision value. [perl #134008]
+New probe for malloc_usable_size
-=item *
+=back
-scalar() on a reference could cause an erroneous assertion failure
-during compilation. [perl #134045]
+=head1 Testing
-=item *
+XXX Any significant changes to the testing of a freshly built perl should be
+listed here. Changes which create B<new> files in F<t/> go here as do any
+large changes to the testing harness (e.g. when parallel testing was added).
+Changes to existing files in F<t/> aren't worth summarizing, although the bugs
+that they represent may be covered elsewhere.
-C<%{^CAPTURE_ALL}> is now an alias to C<%-> as documented, rather than
-incorrectly an alias for C<%+>. [perl #131867]
+XXX If there were no significant test changes, say this:
-=item *
+Tests were added and changed to reflect the other additions and changes
+in this release.
-C<%{^CAPTURE}> didn't work if C<@{^CAPTURE}> was mentioned first.
-Similarly for C<%{^CAPTURE_ALL}> and C<@{^CAPTURE_ALL}>, though
-C<@{^CAPTURE_ALL}> currently isn't used. [perl #131193]
+XXX If instead there were significant changes, say this:
-=item *
+Tests were added and changed to reflect the other additions and
+changes in this release. Furthermore, these significant changes were
+made:
-Extraordinarily large (over 2GB) floating point format widths could
-cause an integer overflow in the underlying call to snprintf(),
-resulting in an assertion. Formatted floating point widths are now
-limited to the range of int, the return value of snprintf(). [perl
-#133913]
+[ List each test improvement as an =item entry ]
+
+=over 4
=item *
-Parsing the following constructs within a sub-parse (such as with
-C<"${code here}"> or C<s/.../code here/e>) has changed to match how
-they're parsed normally:
+XXX
-=over
+=back
-=item *
+=head1 Platform Support
-C<print $fh ...> no longer produces a syntax error.
+XXX Any changes to platform support should be listed in the sections below.
-=item *
+[ Within the sections, list each platform as an =item entry with specific
+changes as paragraphs below it. ]
-Code like C<s/.../ ${time} /e> now properly produces an "Ambiguous use
-of ${time} resolved to $time at ..." warning when warnings are enabled.
+=head2 New Platforms
-=item *
+XXX List any platforms that this version of perl compiles on, that previous
+versions did not. These will either be enabled by new files in the F<hints/>
+directories, or new subdirectories and F<README> files at the top level of the
+source tree.
-C<@x {"a"}> (with the space) in a sub-parse now properly produces a
-"better written as" warning when warnings are enabled.
+=over 4
-=item *
+=item XXX-some-platform
+
+XXX
+
+=back
+
+=head2 Discontinued Platforms
+
+XXX List any platforms that this version of perl no longer compiles on.
+
+=over 4
+
+=item XXX-some-platform
+
+XXX
+
+=back
+
+=head2 Platform-Specific Notes
+
+XXX List any changes for specific platforms. This could include configuration
+and compilation changes or changes in portability/compatibility. However,
+changes within modules for platforms should generally be listed in the
+L</Modules and Pragmata> section.
+
+=over 4
-attributes can now be used in a sub-parse.
+=item Windows
+
+Support for building perl with Visual C++ 6.0 has now been removed.
=back
-[perl #133850]
+=head1 Internal Changes
+
+XXX Changes which affect the interface available to C<XS> code go here. Other
+significant internal changes for future core maintainers should be noted as
+well.
+
+[ List each change as an =item entry ]
+
+=over 4
=item *
-Incomplete hex and binary literals like C<0x> and C<0b> are now
-treated as if the C<x> or C<b> is part of the next token. [perl
-#134125]
+Added the C<<PL_curstackinfo->si_cxsubix>> field. This records the stack
+index of the most recently pushed sub/format/eval context. It is set and
+restored automatically by C<cx_pushsub()>, C<cx_popsub()> etc., but would
+need to be manually managed if you do any unusual manipulation of the
+context stack.
=item *
-A spurious C<)> in a subparse, such as in C<s/.../code here/e> or
-C<"...${code here}">, no longer confuses the parser.
+Various macros dealing with character type classification and changing
+case where the input is encoded in UTF-8 now require an extra parameter
+to prevent potential reads beyond the end of the buffer. Use of these
+has generated a deprecation warning since 5.26. Details are in
+L<perldeprecation/In XS code, use of various macros dealing with UTF-8.>
+
+=back
-Previously a subparse was bracketed with generated C<(> and C<)>
-tokens, so a spurious C<)> would close the construct without doing the
-normal subparse clean up, confusing the parser and possible causing an
-assertion failure.
+=head1 Selected Bug Fixes
-Such constructs are now surrounded by artificial tokens that can't be
-included in the source. [perl #130585]
+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 an =item entry ]
+
+=over 4
=item *
-Reference assignment of a sub, such as C<\&foo = \&bar;>, silently did
-nothing in the C<main::> package. [perl #134072]
+XXX
+
+=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 an =item entry ]
+
+=over 4
=item *
-sv_gets() now recovers better if the target SV is modified by a signal
-handler. [perl #134035]
+XXX
+
+=back
+
+=head1 Errata From Previous Releases
+
+=over 4
=item *
-C<readline @foo> now evaluates C<@foo> in scalar context. Previously
-it would be evalauted in list context, and since readline() pops only
-one argument from the stack, the stack could underflow, or be left
-with unexpected values on the stack. [perl #133989]
+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 or member of the CPAN community has
+died, add a short obituary here.
+
=head1 Acknowledgements
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.31.0..HEAD
+ perl Porting/acknowledgements.pl v5.31.4..HEAD
=head1 Reporting Bugs
If you find what you think is a bug, you might check the perl bug database
at L<https://rt.perl.org/>. There may also be information at
-L<http://www.perl.org/>, the Perl Home Page.
+L<https://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
https://perl5.git.perl.org / perl5.git / blobdiff