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 v5.21.9
12 This document describes differences between the 5.21.8 release and the 5.21.9
15 If you are upgrading from an earlier release such as 5.21.7, first read
16 L<perl5218delta>, which describes differences between 5.21.7 and 5.21.8.
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 ]
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 ]
96 =head1 Modules and Pragmata
98 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
99 go here. If Module::CoreList is updated, generate an initial draft of the
100 following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
101 for important changes should then be added by hand. In an ideal world,
102 dual-life modules would have a F<Changes> file that could be cribbed.
104 [ Within each section, list entries as a =item entry ]
106 =head2 New Modules and Pragmata
116 =head2 Updated Modules and Pragmata
122 L<B> has been upgraded from version 1.55 to 1.56.
126 L<bigint>, L<bignum>, L<bigrat> have been upgraded to version 0.39.
128 Document in CAVEATS that using strings as numbers won't always invoke
129 the big number overloading, and how to invoke it. [perl #123064]
133 L<Devel::Peek> has been upgraded from version 1.21 to 1.22.
137 L<Encode> has been upgraded from version 2.67 to 2.68.
139 Building in C++ mode on Windows now works.
143 L<Opcode> has been upgraded from version 1.31 to 1.32.
147 L<PerlIO::scalar> has been upgraded from version 0.21 to 0.22.
149 Attempting to write at file positions impossible for the platform now
150 fail early rather than wrapping at 4GB.
154 L<Win32> has been upgraded from version 0.49 to 0.51.
156 GetOSName() now supports Windows 8.1, and building in C++ mode now works.
160 L<Win32API::File> has been upgraded from version 0.1201 to 0.1202
162 Building in C++ mode now works.
166 L<POSIX> has been upgraded from version 1.49 to 1.50.
170 =head2 Removed Modules and Pragmata
182 XXX Changes to files in F<pod/> go here. Consider grouping entries by
183 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
185 =head2 New Documentation
187 XXX Changes which create B<new> files in F<pod/> go here.
191 XXX Description of the purpose of the new file here
193 =head2 Changes to Existing Documentation
195 XXX Changes which significantly change existing files in F<pod/> go here.
196 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
205 XXX Description of the change here
215 L<perlfaq> has been synchronized with version 5.021009 from CPAN.
221 The following additions or changes have been made to diagnostic output,
222 including warnings and fatal error messages. For the complete list of
223 diagnostic messages, see L<perldiag>.
225 XXX New or changed warnings emitted by the core's C<C> code go here. Also
226 include any changes in L<perldiag> that reconcile it to the C<C> code.
228 =head2 New Diagnostics
230 XXX Newly added diagnostic messages go under here, separated into New Errors
239 XXX L<message|perldiag/"message">
249 XXX L<message|perldiag/"message">
253 =head2 Changes to Existing Diagnostics
255 XXX Changes (i.e. rewording) of diagnostic messages go here
261 XXX Describe change here
265 =head1 Utility Changes
267 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
268 Most of these are built within the directory F<utils>.
270 [ List utility changes as a =head2 entry for each utility and =item
271 entries for each change
272 Use L<XXX> with program names to get proper documentation linking. ]
284 =head1 Configuration and Compilation
286 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
287 go here. Any other changes to the Perl build process should be listed here.
288 However, any platform-specific changes should be listed in the
289 L</Platform Support> section, instead.
291 [ List changes as a =item entry ].
303 XXX Any significant changes to the testing of a freshly built perl should be
304 listed here. Changes which create B<new> files in F<t/> go here as do any
305 large changes to the testing harness (e.g. when parallel testing was added).
306 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
307 that they represent may be covered elsewhere.
309 [ List each test improvement as a =item entry ]
319 =head1 Platform Support
321 XXX Any changes to platform support should be listed in the sections below.
323 [ Within the sections, list each platform as a =item entry with specific
324 changes as paragraphs below it. ]
328 XXX List any platforms that this version of perl compiles on, that previous
329 versions did not. These will either be enabled by new files in the F<hints/>
330 directories, or new subdirectories and F<README> files at the top level of the
335 =item XXX-some-platform
341 =head2 Discontinued Platforms
343 XXX List any platforms that this version of perl no longer compiles on.
347 =item XXX-some-platform
353 =head2 Platform-Specific Notes
355 XXX List any changes for specific platforms. This could include configuration
356 and compilation changes or changes in portability/compatibility. However,
357 changes within modules for platforms should generally be listed in the
358 L</Modules and Pragmata> section.
364 Perl can now be built in C++ mode on Windows by setting the makefile macro
365 C<USE_CPLUSPLUS> to the value "define".
369 =head1 Internal Changes
371 XXX Changes which affect the interface available to C<XS> code go here. Other
372 significant internal changes for future core maintainers should be noted as
375 [ List each change as a =item entry ]
385 =head1 Selected Bug Fixes
387 XXX Important bug fixes in the core language are summarized here. Bug fixes in
388 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
390 [ List each fix as a =item entry ]
396 The original visible value of C<$/> is now preserved when it is set to
397 an invalid value. Previously if you set C<$/> to a reference to an
398 array, for example, perl would produce a runtime error and not set
399 C<PL_rs>, but perl code that checked C<$/> would see the array
400 reference. [perl #123218]
404 =head1 Known Problems
406 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
407 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
408 platform specific bugs also go here.
410 [ List each fix as a =item entry ]
420 =head1 Errata From Previous Releases
426 XXX Add anything here that we forgot to add, or were mistaken about, in
427 the perldelta of a previous release.
433 XXX If any significant core contributor has died, we've added a short obituary
436 =head1 Acknowledgements
438 XXX Generate this with:
440 perl Porting/acknowledgements.pl v5.21.8..HEAD
442 =head1 Reporting Bugs
444 If you find what you think is a bug, you might check the articles recently
445 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
446 https://rt.perl.org/ . There may also be information at
447 http://www.perl.org/ , the Perl Home Page.
449 If you believe you have an unreported bug, please run the L<perlbug> program
450 included with your release. Be sure to trim your bug down to a tiny but
451 sufficient test case. Your bug report, along with the output of C<perl -V>,
452 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
454 If the bug you are reporting has security implications, which make it
455 inappropriate to send to a publicly archived mailing list, then please send it
456 to perl5-security-report@perl.org. This points to a closed subscription
457 unarchived mailing list, which includes all the core committers, who will be
458 able to help assess the impact of issues, figure out a resolution, and help
459 co-ordinate the release of patches to mitigate or fix the problem across all
460 platforms on which Perl is supported. Please only use this address for
461 security issues in the Perl core, not for modules independently distributed on
466 The F<Changes> file for an explanation of how to view exhaustive details on
469 The F<INSTALL> file for how to build Perl.
471 The F<README> file for general stuff.
473 The F<Artistic> and F<Copying> files for copyright information.