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 v5.21.10
12 This document describes differences between the 5.21.9 release and the 5.21.10
15 If you are upgrading from an earlier release such as 5.21.8, first read
16 L<perl5219delta>, which describes differences between 5.21.8 and 5.21.9.
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 ]
32 XXX Any security-related notices go here. In particular, any security
33 vulnerabilities closed should be noted here rather than in the
34 L</Selected Bug Fixes> section.
36 [ List each security issue as a =head2 entry ]
38 =head1 Incompatible Changes
40 XXX For a release on a stable branch, this section aspires to be:
42 There are no changes intentionally incompatible with 5.XXX.XXX
43 If any exist, they are bugs, and we request that you submit a
44 report. See L</Reporting Bugs> below.
46 [ List each incompatible change as a =head2 entry ]
50 XXX Any deprecated features, syntax, modules etc. should be listed here.
52 =head2 Module removals
54 XXX Remove this section if inapplicable.
56 The following modules will be removed from the core distribution in a
57 future release, and will at that time need to be installed from CPAN.
58 Distributions on CPAN which require these modules will need to list them as
61 The core versions of these modules will now issue C<"deprecated">-category
62 warnings to alert you to this fact. To silence these deprecation warnings,
63 install the modules in question from CPAN.
65 Note that these are (with rare exceptions) fine modules that you are encouraged
66 to continue to use. Their disinclusion from core primarily hinges on their
67 necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
68 not usually on concerns over their design.
74 XXX Note that deprecated modules should be listed here even if they are listed
75 as an updated module in the L</Modules and Pragmata> section.
79 [ List each other deprecation as a =head2 entry ]
81 =head1 Performance Enhancements
83 XXX Changes which enhance performance without changing behaviour go here.
84 There may well be none in a stable release.
86 [ List each enhancement as a =item entry ]
93 C<utf8::native_to_unicode()> and
94 C<utf8::unicode_to_native()> (see L<utf8>)
95 are now optimized out on ASCII platforms.
96 There is now not even a minimal performance hit in writing code portable
97 between ASCII and EBCDIC platforms.
101 =head1 Modules and Pragmata
103 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
104 go here. If Module::CoreList is updated, generate an initial draft of the
105 following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
106 for important changes should then be added by hand. In an ideal world,
107 dual-life modules would have a F<Changes> file that could be cribbed.
109 [ Within each section, list entries as a =item entry ]
111 =head2 New Modules and Pragmata
121 =head2 Updated Modules and Pragmata
127 L<B> has been upgraded from version 1.56 to 1.57.
131 L<B::Deparse> has been upgraded from version 1.33 to 1.34.
133 Deparse C<$#_> as that instead of as C<$#{_}>. [perl #123947]
137 L<CPAN> has been upgraded from version 2.05 to 2.10.
143 Add support for C<Cwd::getdcwd()> and introduce workaround for a misbehaviour
144 seen on Strawberry Perl 5.20.1.
148 Fix C<chdir()> after building dependencies bug.
152 Introduce experimental support for plugins/hooks.
156 Integrate the App::Cpan sources.
160 Do not check recursion on optional dependencies.
164 Sanity check META.yml to contain a hash.
165 L<[cpan #95271]|https://rt.cpan.org/Ticket/Display.html?id=95271>
171 L<CPAN::Meta> has been upgraded from version 2.143240 to 2.150001.
175 L<Data::Dumper> has been upgraded from version 2.157 to 2.158.
179 L<DynaLoader> has been upgraded from version 1.31 to 1.32.
183 L<Encode> has been upgraded from version 2.70 to 2.72.
187 L<encoding> has been upgraded from version 2.13 to 2.14.
191 L<Getopt::Long> has been upgraded from version 2.43 to 2.45.
195 L<locale> has been upgraded from version 1.05 to 1.06.
199 L<Locale::Codes> has been upgraded from version 3.33 to 3.34.
203 L<Module::CoreList> has been reverted from version 5.20150220 to 5.20150320.
207 L<parent> has been upgraded from version 0.228 to 0.232.
209 No changes to installed files other than the version bump.
213 L<Pod::Functions> has been upgraded from version 1.08 to 1.09.
217 L<POSIX> has been upgraded from version 1.51 to 1.52.
221 L<re> has been upgraded from version 0.31 to 0.32.
225 L<Test::Simple> has been reverted from version 1.301001_098 to 1.001014.
229 L<Text::Balanced> has been upgraded from version 2.02 to 2.03.
231 No changes to installed files other than the version bump.
235 L<Text::ParseWords> has been upgraded from version 3.29 to 3.30.
239 L<threads> has been upgraded from version 1.96_001 to 2.01.
243 L<utf8> has been upgraded from version 1.14 to 1.15.
247 L<XS::APItest> has been upgraded from version 0.70 to 0.71.
251 =head2 Removed Modules and Pragmata
263 XXX Changes to files in F<pod/> go here. Consider grouping entries by
264 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
266 =head2 New Documentation
268 XXX Changes which create B<new> files in F<pod/> go here.
272 XXX Description of the purpose of the new file here
274 =head2 Changes to Existing Documentation
276 XXX Changes which significantly change existing files in F<pod/> go here.
277 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
286 Documentation has been added regarding the special floating point values C<Inf>
291 =head3 L<perlexperiment>
297 Removed note about C<\s> matching C<VT> now that it is no longer experimental.
301 Added note that C<use re 'strict'> has been introduced experimentally.
311 The documentation of what to expect to see in future maintenance releases has
312 been updated. Essentially the same types of changes will be included as before
313 but with fewer changes that don't affect the installation or execution of perl.
319 The following additions or changes have been made to diagnostic output,
320 including warnings and fatal error messages. For the complete list of
321 diagnostic messages, see L<perldiag>.
323 XXX New or changed warnings emitted by the core's C<C> code go here. Also
324 include any changes in L<perldiag> that reconcile it to the C<C> code.
326 =head2 New Diagnostics
328 XXX Newly added diagnostic messages go under here, separated into New Errors
337 L<Invalid quantifier in {,} in regex; marked by <-- HERE in mE<sol>%sE<sol>|perldiag/"Invalid quantifier in {,} in regex; marked by <-- HERE in m/%s/">
339 (F) The pattern looks like a {min,max} quantifier, but the min or max could not
340 be parsed as a valid number - either it has leading zeroes, or it represents
341 too big a number to cope with. The S<<-- HERE> shows where in the regular
342 expression the problem was discovered. See L<perlre>.
352 XXX L<message|perldiag/"message">
356 =head2 Changes to Existing Diagnostics
358 XXX Changes (i.e. rewording) of diagnostic messages go here
364 XXX Describe change here
368 =head1 Utility Changes
370 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
371 Most of these are built within the directory F<utils>.
373 [ List utility changes as a =head2 entry for each utility and =item
374 entries for each change
375 Use L<XXX> with program names to get proper documentation linking. ]
387 =head1 Configuration and Compilation
389 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
390 go here. Any other changes to the Perl build process should be listed here.
391 However, any platform-specific changes should be listed in the
392 L</Platform Support> section, instead.
394 [ List changes as a =item entry ].
406 XXX Any significant changes to the testing of a freshly built perl should be
407 listed here. Changes which create B<new> files in F<t/> go here as do any
408 large changes to the testing harness (e.g. when parallel testing was added).
409 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
410 that they represent may be covered elsewhere.
412 [ List each test improvement as a =item entry ]
418 Tests for performance issues have been added in the file F<t/perf/taint.t>.
422 =head1 Platform Support
424 XXX Any changes to platform support should be listed in the sections below.
426 [ Within the sections, list each platform as a =item entry with specific
427 changes as paragraphs below it. ]
431 XXX List any platforms that this version of perl compiles on, that previous
432 versions did not. These will either be enabled by new files in the F<hints/>
433 directories, or new subdirectories and F<README> files at the top level of the
438 =item XXX-some-platform
444 =head2 Discontinued Platforms
446 XXX List any platforms that this version of perl no longer compiles on.
450 =item XXX-some-platform
456 =head2 Platform-Specific Notes
458 XXX List any changes for specific platforms. This could include configuration
459 and compilation changes or changes in portability/compatibility. However,
460 changes within modules for platforms should generally be listed in the
461 L</Modules and Pragmata> section.
465 =item XXX-some-platform
471 =head1 Internal Changes
473 XXX Changes which affect the interface available to C<XS> code go here. Other
474 significant internal changes for future core maintainers should be noted as
477 [ List each change as a =item entry ]
483 Macros have been created to allow XS code to better manipulate the POSIX
484 locale category C<LC_NUMERIC>.
485 See L<perlapi/Locale-related functions and macros>.
489 =head1 Selected Bug Fixes
491 XXX Important bug fixes in the core language are summarized here. Bug fixes in
492 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
494 [ List each fix as a =item entry ]
500 Repeated global pattern matches in scalar context on large tainted
501 strings were exponentially slow depending on the current match
502 position in the string. [perl #123202]
506 =head1 Known Problems
508 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
509 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
510 platform specific bugs also go here.
512 [ List each fix as a =item entry ]
522 =head1 Errata From Previous Releases
528 XXX Add anything here that we forgot to add, or were mistaken about, in
529 the perldelta of a previous release.
535 XXX If any significant core contributor has died, we've added a short obituary
538 =head1 Acknowledgements
540 XXX Generate this with:
542 perl Porting/acknowledgements.pl v5.21.9..HEAD
544 =head1 Reporting Bugs
546 If you find what you think is a bug, you might check the articles recently
547 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
548 https://rt.perl.org/ . There may also be information at
549 http://www.perl.org/ , the Perl Home Page.
551 If you believe you have an unreported bug, please run the L<perlbug> program
552 included with your release. Be sure to trim your bug down to a tiny but
553 sufficient test case. Your bug report, along with the output of C<perl -V>,
554 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
556 If the bug you are reporting has security implications, which make it
557 inappropriate to send to a publicly archived mailing list, then please send it
558 to perl5-security-report@perl.org. This points to a closed subscription
559 unarchived mailing list, which includes all the core committers, who will be
560 able to help assess the impact of issues, figure out a resolution, and help
561 co-ordinate the release of patches to mitigate or fix the problem across all
562 platforms on which Perl is supported. Please only use this address for
563 security issues in the Perl core, not for modules independently distributed on
568 The F<Changes> file for an explanation of how to view exhaustive details on
571 The F<INSTALL> file for how to build Perl.
573 The F<README> file for general stuff.
575 The F<Artistic> and F<Copying> files for copyright information.