=head1 NAME
-[ this is a template for a new perldelta file. Any text flagged as
-XXX needs to be processed before release. ]
+[ 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 v5.17.2
+perldelta - what is new for perl v5.17.3
=head1 DESCRIPTION
-This document describes differences between the 5.17.1 release and
-the 5.17.2 release.
+This document describes differences between the 5.17.2 release and the 5.17.3
+release.
-If you are upgrading from an earlier release such as 5.17.0, first read
-L<perl5171delta>, which describes differences between 5.17.0 and
-5.17.1.
+If you are upgrading from an earlier release such as 5.17.1, first read
+L<perl5172delta>, which describes differences between 5.17.1 and 5.17.2.
=head1 Notice
=head1 Core Enhancements
-XXX New core language features go here. Summarise user-visible core language
-enhancements. Particularly prominent performance optimisations could go
+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 Computed Labels
+
+The loop controls C<next>, C<last> and C<redo>, and the special C<dump>
+operator, now allow arbitrary expressions to be used to compute labels at
+run time. Previously, any argument that was not a constant was treated as
+the empty string.
+
=head1 Security
XXX Any security-related notices go here. In particular, any security
=head1 Incompatible Changes
-XXX For a release on a stable branch, this section aspires to be:
+[ List each incompatible change as a =head2 entry ]
- 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 C<$ENV{foo} = undef> deletes value from environ, like C<delete $ENV{foo}>
-[ List each incompatible change as a =head2 entry ]
+This facilitates use of C<local()> with C<%ENV> entries. In previous
+versions of Perl, C<undef> was converted to the empty string.
+
+=head2 Defined values stored in environment are forced to byte strings
+
+A value stored in an environment variable has always been stringified. In
+this release, it is converted to be only a byte string. First, it is forced
+to be a only a string. Then if the string is utf8 and the equivalent of
+C<utf8::downgrade()> works, that result is used; otherwise, the equivalent of
+C<utf8::encode()> is used, and a warning is issued about wide characters
+(L</Diagnostics>).
+
+=head2 C<given> now aliases the global C<$_>
+
+Instead of assigning to an implicit lexical C<$_>, C<given> now makes the
+global C<$_> an alias for its argument, just like C<foreach>. However, it
+still uses lexical C<$_> if there is lexical C<$_> in scope (again, just like
+C<foreach>).
=head1 Deprecations
-XXX Any deprecated features, syntax, modules etc. should be listed here.
-In particular, deprecated modules should be listed here even if they are
-listed as an updated module in the L</Modules and Pragmata> section.
+XXX Any deprecated features, syntax, modules etc. should be listed here. In
+particular, deprecated modules should be listed here even if they are listed as
+an updated module in the L</Modules and Pragmata> section.
[ List each 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.
+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 ]
=item *
-L<File::stat> has been upgraded from version 1.06 to 1.07.
+L<B> has been upgraded from version 1.36 to 1.37. All C<CVf_*> and C<GVf_*>
+and more SV-related flag values are now provided as constants in the C<B::>
+namespace and available for export. The default export list has not changed.
+
+=item *
+
+L<B::Concise> has been upgraded from version 1.91 to 1.92. XXX Add change
+notes.
+
+=item *
+
+L<B::Deparse> has been upgraded from version 1.15 to 1.16. It now deparses
+loop controls with the correct precedence.
+
+=item *
+
+L<Compress::Raw::Bzip2> has been upgraded from version 2.05201 to 2.055. XXX
+Add change notes.
+
+=item *
+
+L<Compress::Raw::Zlib> has been upgraded from version 2.05401 to 2.056. XXX
+Add change notes.
+
+=item *
+
+L<Data::Dumper> has been upgraded from version 2.135_06 to 2.135_07. It has
+been optimized to only build a seen-scalar hash as necessary, thereby speeding
+up serialization drastically.
+
+=item *
+
+L<Devel::Peek> has been upgraded from version 1.08 to 1.09. XXX Add change
+notes.
+
+=item *
+
+L<Encode> has been upgraded from version 2.44 to 2.46. XXX Add change notes.
+
+=item *
-Previously C<File::stat>'s overloaded C<-x> and C<-X> operators did not give
-the correct results for directories or executable files when running as
-root. They had been treating executable permissions for root just like for
-any other user, performing group membership tests I<etc> for files not owned
-by root. They now follow the correct Unix behaviour - for a directory they
-are always true, and for a file if any of the three execute permission bits
-are set then they report that root can execute the file. Perl's builtin
-C<-x> and C<-X> operators have always been correct.
+L<IO::Compress> has been upgraded from version 2.052 to 2.055. XXX Add change
+notes.
=item *
-L<Tie::StdHandle> has been upgraded from version 4.2 to 4.3.
+L<Module::Build> has been upgraded from version 0.40 to 0.4002. XXX Add change
+notes.
-C<READ> now respects the offset argument to C<read> [perl #112826].
+=item *
+
+L<Module::CoreList> has been upgraded from version 2.69 to 2.70. XXX Add
+change notes.
+
+=item *
+
+L<Module::Load::Conditional> has been upgraded from version 0.50 to 0.54. XXX
+Add change notes.
+
+=item *
+
+L<Module::Metadata> has been upgraded from version 1.000009 to 1.000010. XXX
+Add change notes.
+
+=item *
+
+L<re> has been upgraded from version 0.21 to 0.22. XXX Add change notes.
+
+=item *
+
+L<Storable> has been upgraded from version 2.37 to 2.38. It can now freeze
+and thaw vstrings correctly. This causes a slight incompatible change in
+the storage format, so the format version has increased to 2.9.
+
+=item *
+
+L<Time::Local> has been upgraded from version 1.2000 to 1.2300. XXX Add change
+notes.
+
+=item *
+
+L<Unicode::UCD> has been upgraded from version 0.44 to 0.45. XXX Add change
+notes.
+
+=item *
+
+L<Win32CORE> has been upgraded from version 0.02 to 0.03. XXX Add change
+notes.
=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>.
+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
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<XXX>
+=head3 L<perlfunc>, L<perlop>
=over 4
=item *
-XXX Description of the change here
+Loop control verbs (C<dump>, C<goto>, C<next>, C<last> and C<redo>) have
+always had the same precedence as assignment operators, but this was never
+documented until now.
=back
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
+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.
-[ Within each section, list entries as a =item entry that links to perldiag,
- e.g.
-
- =item *
-
- L<Invalid version object|perldiag/"Invalid version object">
-]
-
=head2 New Diagnostics
-XXX Newly added diagnostic messages go here
+XXX Newly added diagnostic messages go under here, separated into New Errors
+and New Warnings
=head3 New Errors
=item *
-L<message|perldiag/"message">
+L<Unterminated delimiter for here document|perldiag/"Unterminated delimiter for here document">
+
+This message now occurs when a here document label has an initial quotation
+mark but the final quotation mark is missing.
+
+This replaces a bogus and misleading error message about not finding the
+label itself [perl #114104].
=back
=item *
-C<chr()> now warns when passed a negative value [perl #83048].
+L<Wide character in setenv|perldiag/"Wide character in setenv">
-=item *
-
-C<srand()> now warns when passed a value that doesn't fit in a C<UV> (since the
-value will be truncated rather than overflowing) [perl #40605].
+Attempts to put wide characters into environment variables via C<%ENV> now
+provoke this warning.
=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 directories F<utils> and F<x2p>.
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
+Most of these are built within the directories F<utils> and F<x2p>.
[ List utility changes as a =head3 entry for each utility and =item
entries for each change
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 summarising, although the bugs
+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 ]
=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/>
+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.
=head2 Platform-Specific Notes
-XXX List any changes for specific platforms. This could include configuration
+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.
=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.
+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 ]
=head1 Selected Bug Fixes
-XXX Important bug fixes in the core language are summarised here.
-Bug fixes in files in F<ext/> and F<lib/> are best summarised in
-L</Modules and Pragmata>.
+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 ]
=item *
-A regression introduced in v5.14.0 has been fixed, in which some calls
-to the C<re> module would clobber C<$_>.
+C<\w> now matches the code points U+200C (ZERO WIDTH NON-JOINER) and
+U+200D (ZERO WIDTH JOINER). C<\W> no longer matches these. This change
+is because Unicode corrected their definition of what C<\w> should match.
=item *
-C<do FILE> now always either sets or clears C<$@>, even when the file can't be
-read. This ensures that testing C<$@> first (as recommended by the
-documentation) always returns the correct result.
+C<dump LABEL> no longer leaks its label.
=item *
-The array iterator used for the C<each @array> construct is now correctly
-reset when C<@array> is cleared (RT #75596). This happens for example when the
-array is globally assigned to, as in C<@array = (...)>, but not when its
-B<values> are assigned to. In terms of the XS API, it means that C<av_clear()>
-will now reset the iterator.
-
-This mirrors the behaviour of the hash iterator when the hash is cleared.
+Constant folding no longer changes the behaviour of functions like C<stat()>
+and C<truncate()> that can take either filenames or handles.
+C<stat 1 ? foo : bar> nows treats its argument as a file name (since it is
+an arbitrary expression), rather than the handle "foo".
=item *
-C<< $class->can >>, C<< $class->isa >>, and C<< $class->DOES >> now return
-correct results, regardless of whether that package referred to by C<$class>
-exists [perl #47113].
+C<truncate FOO, $len> no longer falls back to treating "FOO" as a file name
+if the filehandle has been deleted. This was broken in Perl 5.16.0.
=item *
-Arriving signals no longer clear C<$@> [perl #45173].
+Subroutine redefinitions after sub-to-glob and glob-to-glob assignments no
+longer cause double frees or panic messages.
=item *
-Allow C<my ()> declarations with an empty variable list [perl #113554].
+C<s///> now turns vstrings into plain strings when performing a
+substitution, even if the resulting string is the same (C<s/a/a/>).
=item *
-During parsing, subs declared after errors no longer leave stubs
-[perl #113712].
+Prototype mismatch warnings no longer erroneously treat constant subs as
+having no prototype when they actually have "".
=item *
-C<do $file> now clears C<$@> after an I/O error [perl #113730].
+Constant subroutines and forward declarations no longer prevent prototype
+mismatch warnings from omitting the sub name.
=item *
-Closures containing no string evals no longer hang on to their containing
-subroutines, allowing variables closed over by outer subroutines to be
-freed when the outer sub is freed, even if the inner sub still exists
-[perl #89544].
+C<undef> on a subroutine now clears call checkers.
=item *
-Duplication of in-memory filehandles by opening with a "<&=" or ">&=" mode
-stopped working properly in 5.16.0. It was causing the new handle to
-reference a different scalar variable. This has been fixed [perl #113764].
+The C<ref> operator started leaking memory on blessed objects in Perl
+5.16.0. This has been fixed [perl #114340].
=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
+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 ]
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.17.1..HEAD
+ perl Porting/acknowledgements.pl v5.17.2..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 http://rt.perl.org/perlbug/ . There may also be
-information at http://www.perl.org/ , the Perl Home Page.
+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
+http://rt.perl.org/perlbug/ . 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 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
+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.
+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<Changes> file for an explanation of how to view exhaustive details on
+what changed.
The F<INSTALL> file for how to build Perl.
https://perl5.git.perl.org / perl5.git / blobdiff