5 [ this is a template for a new perldelta file. Any text flagged as XXX needs
6 to be processed before release. ]
8 perldelta - what is new for perl v5.17.9
12 This document describes differences between the 5.17.8 release and the 5.17.9
15 If you are upgrading from an earlier release such as 5.17.7, first read
16 L<perl5178delta>, which describes differences between 5.17.7 and 5.17.8.
20 XXX Any important notices here
22 =head1 Core Enhancements
24 XXX New core language features go here. Summarize user-visible core language
25 enhancements. Particularly prominent performance optimisations could go
26 here, but most should go in the L</Performance Enhancements> section.
28 [ List each enhancement as a =head2 entry ]
30 =head2 Interpolations now Accepted in Regular Expression Set Operations
32 Perl v5.17.8 introduced L<regular expression set operations|perlre/(?[ ])>.
33 They have now been expanded to allow the interpolation of a
34 previously-compiled set into a bigger set, like this:
36 my $thai_or_lao = qr/\p{Thai} + \p{Lao}/;
38 qr/(?[ \p{Digit} & $thai_or_lao ])/;
42 XXX Any security-related notices go here. In particular, any security
43 vulnerabilities closed should be noted here rather than in the
44 L</Selected Bug Fixes> section.
46 [ List each security issue as a =head2 entry ]
48 =head1 Incompatible Changes
50 XXX For a release on a stable branch, this section aspires to be:
52 There are no changes intentionally incompatible with 5.XXX.XXX
53 If any exist, they are bugs, and we request that you submit a
54 report. See L</Reporting Bugs> below.
56 =head2 C<$ENV{foo} = undef> no longer deletes value from environ
58 5.17.3 Introduced a change where assiging C<undef> to an C<%ENV> key was equivalent
59 to C<delete $ENV{foo}>.
61 This release reverts that change.
63 [ List each incompatible change as a =head2 entry ]
67 XXX Any deprecated features, syntax, modules etc. should be listed here. In
68 particular, deprecated modules should be listed here even if they are listed as
69 an updated module in the L</Modules and Pragmata> section.
71 [ List each deprecation as a =head2 entry ]
73 =head2 Deprecated Modules
75 The following modules will be removed from the core distribution in a
76 future release, and should be installed from CPAN instead. Distributions
77 on CPAN which require these should add them to their prerequisites. The
78 core versions of these modules C<warnings> will issue a deprecation warning.
80 You can silence these deprecation warnings by installing the modules
81 in question from CPAN.
85 =item L<Archive::Extract>
89 =item L<B::Lint::Debug>
93 =item L<CPANPLUS::Backend>
95 =item L<CPANPLUS::Backend::RV>
97 =item L<CPANPLUS::Config>
99 =item L<CPANPLUS::Config::HomeEnv>
101 =item L<CPANPLUS::Configure>
103 =item C<CPANPLUS::Configure::Setup>
105 =item L<CPANPLUS::Dist>
107 =item L<CPANPLUS::Dist::Autobundle>
109 =item L<CPANPLUS::Dist::Base>
111 =item L<CPANPLUS::Dist::Build>
113 =item L<CPANPLUS::Dist::Build::Constants>
115 =item L<CPANPLUS::Dist::MM>
117 =item L<CPANPLUS::Dist::Sample>
119 =item L<CPANPLUS::Error>
121 =item L<CPANPLUS::Internals>
123 =item C<CPANPLUS::Internals::Constants>
125 =item C<CPANPLUS::Internals::Constants::Report>
127 =item L<CPANPLUS::Internals::Extract>
129 =item L<CPANPLUS::Internals::Fetch>
131 =item L<CPANPLUS::Internals::Report>
133 =item L<CPANPLUS::Internals::Search>
135 =item L<CPANPLUS::Internals::Source>
137 =item L<CPANPLUS::Internals::Source::Memory>
139 =item L<CPANPLUS::Internals::Source::SQLite>
141 =item C<CPANPLUS::Internals::Source::SQLite::Tie>
143 =item L<CPANPLUS::Internals::Utils>
145 =item C<CPANPLUS::Internals::Utils::Autoflush>
147 =item L<CPANPLUS::Module>
149 =item L<CPANPLUS::Module::Author>
151 =item L<CPANPLUS::Module::Author::Fake>
153 =item L<CPANPLUS::Module::Checksums>
155 =item L<CPANPLUS::Module::Fake>
157 =item C<CPANPLUS::Module::Signature>
159 =item L<CPANPLUS::Selfupdate>
161 =item L<CPANPLUS::Shell>
163 =item L<CPANPLUS::Shell::Classic>
165 =item L<CPANPLUS::Shell::Default>
167 =item L<CPANPLUS::Shell::Default::Plugins::CustomSource>
169 =item L<CPANPLUS::Shell::Default::Plugins::Remote>
171 =item L<CPANPLUS::Shell::Default::Plugins::Source>
173 =item L<Devel::InnerPackage>
175 =item L<Log::Message>
177 =item L<Log::Message::Config>
179 =item L<Log::Message::Handlers>
181 =item L<Log::Message::Item>
183 =item L<Log::Message::Simple>
185 =item L<Module::Pluggable>
187 =item L<Module::Pluggable::Object>
189 =item L<Object::Accessor>
193 =item L<Term::UI::History>
197 =head3 Deprecated Utilities
199 The following utilities will be removed from the core distribution in a
200 future release as their associated modules have been deprecated. They
201 will remain available with the applicable CPAN distribution.
207 Included with L<CPANPLUS>.
209 =item C<cpanp-run-perl>
211 Included with L<CPANPLUS>.
215 Included with L<CPANPLUS>.
219 The L<Pod::LaTeX> module was deprecated with 5.17.8.
223 =head2 Five additional characters should be escaped in patterns with C</x>
225 When a regular expression pattern is compiled with C</x>, Perl treats 6
226 characters as white space to ignore, such as SPACE and TAB. However,
227 Unicode recommends 11 characters be treated thusly. In preparation to
228 conforming with this in a future Perl version, in the meantime, use of
229 any of the missing characters will raise a deprecation warning, unless
230 turned off. The five characters are:
232 U+200E LEFT-TO-RIGHT MARK,
233 U+200F RIGHT-TO-LEFT MARK,
234 U+2028 LINE SEPARATOR,
236 U+2029 PARAGRAPH SEPARATOR.
238 =head1 Performance Enhancements
240 XXX Changes which enhance performance without changing behaviour go here.
241 There may well be none in a stable release.
243 [ List each enhancement as a =item entry ]
253 =head1 Modules and Pragmata
255 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
256 go here. If Module::CoreList is updated, generate an initial draft of the
257 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
258 entries to STDOUT. Results can be pasted in place of the '=head2' entries
259 below. A paragraph summary for important changes should then be added by hand.
260 In an ideal world, dual-life modules would have a F<Changes> file that could be
263 [ Within each section, list entries as a =item entry ]
265 =head2 New Modules and Pragmata
271 L<Config::Perl::V> version 0.16 has been added as a dual-lifed module.
272 It provides structured data retrieval of C<perl -V> output including
273 information only known to the C<perl> binary and not available via L<Config>.
277 =head2 Updated Modules and Pragmata
283 L<Benchmark> has been upgraded from version 1.13 to 1.14.
285 The "too few iterations" message is now a warning on STDERR
286 instead of being output on STDOUT.
290 L<Data::Dumper> has been upgraded from version 2.141 to 2.142.
292 Additional tests were added in order to improve statement, branch, condition
293 and subroutine coverage. On the basis of the coverage analysis, some of the
294 internals of Dumper.pm were refactored. Almost all methods are now
299 L<File::Temp> has been upgraded from version 0.22 to 0.22_90
301 Fixes various bugs involving directory removal. Defers unlinking tempfiles if
302 the initial unlink fails, which fixes problems on NFS.
306 L<PerlIO::scalar> has been upgraded from version 0.15 to 0.16.
308 The buffer scalar supplied may now only contain code pounts 0xFF or
309 lower. [perl #109828]
313 =head2 Removed Modules and Pragmata
325 XXX Changes to files in F<pod/> go here. Consider grouping entries by
326 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
328 =head2 New Documentation
330 XXX Changes which create B<new> files in F<pod/> go here.
334 XXX Description of the purpose of the new file here
336 =head2 Changes to Existing Documentation
338 XXX Changes which significantly change existing files in F<pod/> go here.
339 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
348 A syntax error was fixed in one of illustrative examples.
354 The following additions or changes have been made to diagnostic output,
355 including warnings and fatal error messages. For the complete list of
356 diagnostic messages, see L<perldiag>.
358 XXX New or changed warnings emitted by the core's C<C> code go here. Also
359 include any changes in L<perldiag> that reconcile it to the C<C> code.
361 =head2 New Diagnostics
363 XXX Newly added diagnostic messages go under here, separated into New Errors
372 XXX L<message|perldiag/"message">
382 Strings with code points over 0xFF may not be mapped into in-memory file handles
386 =head2 Changes to Existing Diagnostics
388 XXX Changes (i.e. rewording) of diagnostic messages go here
394 The warnings for \b{ and \B{ were added in the 5.17 series; they are a
395 deprecation warning which should be turned off by that category. One
396 should not have to turn off regular regexp warnings as well to get rid
401 =head1 Utility Changes
403 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
404 Most of these are built within the directories F<utils> and F<x2p>.
406 [ List utility changes as a =head3 entry for each utility and =item
407 entries for each change
408 Use L<XXX> with program names to get proper documentation linking. ]
416 Added C<--feature> switch which lists the first version bundle of each
421 =head1 Configuration and Compilation
423 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
424 go here. Any other changes to the Perl build process should be listed here.
425 However, any platform-specific changes should be listed in the
426 L</Platform Support> section, instead.
428 [ List changes as a =item entry ].
434 Added C<useversionedarchname> option to Configure
436 When set, it includes 'api_versionstring' in 'archname'. E.g.
437 x86_64-linux-5.13.6-thread-multi. It is unset by default.
439 This feature was requested by Tim Bunce, who observed that
440 INSTALL_BASE creates a library structure that does not
441 differentiate by perl version. Instead, it places architecture
442 specific files in "$install_base/lib/perl5/$archname". This makes
443 it difficult to use a common INSTALL_BASE library path with
444 multiple versions of perl.
446 By setting -Duseversionedarchname, the $archname will be
447 distinct for architecture *and* API version, allowing mixed use of
452 Configure will honour the external C<MAILDOMAIN> environment variable, if set.
456 Both C<META.yml> and C<META.json> files are now included in the distribution.
462 XXX Any significant changes to the testing of a freshly built perl should be
463 listed here. Changes which create B<new> files in F<t/> go here as do any
464 large changes to the testing harness (e.g. when parallel testing was added).
465 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
466 that they represent may be covered elsewhere.
468 [ List each test improvement as a =item entry ]
474 Enable perl core tests to pass when locale support is not available.
476 use L<locale> - this will now die if $Config{d_setlocale} is not true.
477 All tests that use L<locale> will skip if $Config{d_setlocale} is not true.
478 This enables us to pass tests on Android which uses ICU instead of locales.
482 =head1 Platform Support
484 XXX Any changes to platform support should be listed in the sections below.
486 [ Within the sections, list each platform as a =item entry with specific
487 changes as paragraphs below it. ]
491 XXX List any platforms that this version of perl compiles on, that previous
492 versions did not. These will either be enabled by new files in the F<hints/>
493 directories, or new subdirectories and F<README> files at the top level of the
498 =item XXX-some-platform
504 =head2 Discontinued Platforms
506 XXX List any platforms that this version of perl no longer compiles on.
510 =item XXX-some-platform
516 =head2 Platform-Specific Notes
518 XXX List any changes for specific platforms. This could include configuration
519 and compilation changes or changes in portability/compatibility. However,
520 changes within modules for platforms should generally be listed in the
521 L</Modules and Pragmata> section.
527 The character set for Extended Filename Syntax (EFS) is now enabled by default on
528 VMS. Among other things, this provides better handling of dots in directory names,
529 multiple dots in filenames,and spaces in filenames. To obtain the old behavior,
530 set the logical name C<DECC$EFS_CHARSET> to C<DISABLE>.
534 =head1 Internal Changes
536 XXX Changes which affect the interface available to C<XS> code go here. Other
537 significant internal changes for future core maintainers should be noted as
540 [ List each change as a =item entry ]
546 Synonyms for the misleadingly named C<av_len()> has been created:
547 C<av_top_index()> and C<av_tindex>. All three of these return the
548 number of the highest index in the array, not the number of elements it
549 contains. (The name C<av_top> which was introduced in Perl v.5.17.8 has
556 =head1 Selected Bug Fixes
558 XXX Important bug fixes in the core language are summarized here. Bug fixes in
559 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
561 [ List each fix as a =item entry ]
567 -DPERL_GLOBAL_STRUCT builds now free the global struct B<after>
568 they've finished using it.
572 A trailing '/' on a path in @INC will no longer have an additional '/' appended.
576 =head1 Known Problems
578 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
579 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
580 platform specific bugs also go here.
582 [ List each fix as a =item entry ]
594 XXX If any significant core contributor has died, we've added a short obituary
597 =head1 Acknowledgements
599 XXX Generate this with:
601 perl Porting/acknowledgements.pl v5.17.8..HEAD
603 =head1 Reporting Bugs
605 If you find what you think is a bug, you might check the articles recently
606 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
607 http://rt.perl.org/perlbug/ . There may also be information at
608 http://www.perl.org/ , the Perl Home Page.
610 If you believe you have an unreported bug, please run the L<perlbug> program
611 included with your release. Be sure to trim your bug down to a tiny but
612 sufficient test case. Your bug report, along with the output of C<perl -V>,
613 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
615 If the bug you are reporting has security implications, which make it
616 inappropriate to send to a publicly archived mailing list, then please send it
617 to perl5-security-report@perl.org. This points to a closed subscription
618 unarchived mailing list, which includes all the core committers, who will be
619 able to help assess the impact of issues, figure out a resolution, and help
620 co-ordinate the release of patches to mitigate or fix the problem across all
621 platforms on which Perl is supported. Please only use this address for
622 security issues in the Perl core, not for modules independently distributed on
627 The F<Changes> file for an explanation of how to view exhaustive details on
630 The F<INSTALL> file for how to build Perl.
632 The F<README> file for general stuff.
634 The F<Artistic> and F<Copying> files for copyright information.