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 v5.17.10
12 This document describes differences between the 5.17.9 release and the 5.17.10
15 If you are upgrading from an earlier release such as 5.17.8, first read
16 L<perl5179delta>, which describes differences between 5.17.8 and 5.17.9.
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. In
51 particular, deprecated modules should be listed here even if they are listed as
52 an updated module in the L</Modules and Pragmata> section.
54 [ List each deprecation as a =head2 entry ]
56 =head1 Performance Enhancements
58 XXX Changes which enhance performance without changing behaviour go here.
59 There may well be none in a stable release.
61 [ List each enhancement as a =item entry ]
71 =head1 Modules and Pragmata
73 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
74 go here. If Module::CoreList is updated, generate an initial draft of the
75 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
76 entries to STDOUT. Results can be pasted in place of the '=head2' entries
77 below. A paragraph summary for important changes should then be added by hand.
78 In an ideal world, dual-life modules would have a F<Changes> file that could be
81 [ Within each section, list entries as a =item entry ]
83 =head2 New Modules and Pragmata
93 =head2 Updated Modules and Pragmata
99 L<Benchmark> has been upgraded from version 1.14 to 1.15.
101 This reverts (for now) a change in 1.14 whereby the "too few iterations"
102 message became a warning on STDERR instead of being output on STDOUT. It's
107 =head2 Removed Modules and Pragmata
119 XXX Changes to files in F<pod/> go here. Consider grouping entries by
120 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
122 =head2 New Documentation
124 XXX Changes which create B<new> files in F<pod/> go here.
128 XXX Description of the purpose of the new file here
130 =head2 Changes to Existing Documentation
132 XXX Changes which significantly change existing files in F<pod/> go here.
133 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
136 =head3 L<perlrebackslash/\N>
142 This feature is no longer experimental.
148 The following additions or changes have been made to diagnostic output,
149 including warnings and fatal error messages. For the complete list of
150 diagnostic messages, see L<perldiag>.
152 XXX New or changed warnings emitted by the core's C<C> code go here. Also
153 include any changes in L<perldiag> that reconcile it to the C<C> code.
155 =head2 New Diagnostics
157 XXX Newly added diagnostic messages go under here, separated into New Errors
166 XXX L<message|perldiag/"message">
176 XXX L<message|perldiag/"message">
180 =head2 Changes to Existing Diagnostics
182 XXX Changes (i.e. rewording) of diagnostic messages go here
188 XXX Describe change here
192 =head1 Utility Changes
194 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
195 Most of these are built within the directories F<utils> and F<x2p>.
197 [ List utility changes as a =head3 entry for each utility and =item
198 entries for each change
199 Use L<XXX> with program names to get proper documentation linking. ]
211 =head1 Configuration and Compilation
213 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
214 go here. Any other changes to the Perl build process should be listed here.
215 However, any platform-specific changes should be listed in the
216 L</Platform Support> section, instead.
218 [ List changes as a =item entry ].
230 XXX Any significant changes to the testing of a freshly built perl should be
231 listed here. Changes which create B<new> files in F<t/> go here as do any
232 large changes to the testing harness (e.g. when parallel testing was added).
233 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
234 that they represent may be covered elsewhere.
236 [ List each test improvement as a =item entry ]
246 =head1 Platform Support
248 XXX Any changes to platform support should be listed in the sections below.
250 [ Within the sections, list each platform as a =item entry with specific
251 changes as paragraphs below it. ]
255 XXX List any platforms that this version of perl compiles on, that previous
256 versions did not. These will either be enabled by new files in the F<hints/>
257 directories, or new subdirectories and F<README> files at the top level of the
262 =item XXX-some-platform
268 =head2 Discontinued Platforms
270 XXX List any platforms that this version of perl no longer compiles on.
274 =item XXX-some-platform
280 =head2 Platform-Specific Notes
282 XXX List any changes for specific platforms. This could include configuration
283 and compilation changes or changes in portability/compatibility. However,
284 changes within modules for platforms should generally be listed in the
285 L</Modules and Pragmata> section.
289 =item XXX-some-platform
295 =head1 Internal Changes
297 XXX Changes which affect the interface available to C<XS> code go here. Other
298 significant internal changes for future core maintainers should be noted as
301 [ List each change as a =item entry ]
307 The new copy-on-write mechanism that was introduced in 5.17.7 has now been
308 disabled by default, since it was felt that there were too many rough
309 edges for the 5.18 release. It is expected that it will be enabled by
312 This change also re-enables PL_sawampersand by default.
314 It can be enabled in a perl build by running F<Configure> with
315 B<-Accflags=-DPERL_NEW_COPY_ON_WRITE>, and we would encourage XS authors to
316 try their code with such an enabled perl, and provide feedback.
317 XXX need blurb, e.g. a reference to a new section in perlguts or perlxs
318 explaining how XS authors should handle COW strings.
323 =head1 Selected Bug Fixes
325 XXX Important bug fixes in the core language are summarized here. Bug fixes in
326 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
328 [ List each fix as a =item entry ]
338 =head1 Known Problems
340 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
341 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
342 platform specific bugs also go here.
344 [ List each fix as a =item entry ]
356 XXX If any significant core contributor has died, we've added a short obituary
359 =head1 Acknowledgements
361 XXX Generate this with:
363 perl Porting/acknowledgements.pl v5.17.9..HEAD
365 =head1 Reporting Bugs
367 If you find what you think is a bug, you might check the articles recently
368 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
369 http://rt.perl.org/perlbug/ . There may also be information at
370 http://www.perl.org/ , the Perl Home Page.
372 If you believe you have an unreported bug, please run the L<perlbug> program
373 included with your release. Be sure to trim your bug down to a tiny but
374 sufficient test case. Your bug report, along with the output of C<perl -V>,
375 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
377 If the bug you are reporting has security implications, which make it
378 inappropriate to send to a publicly archived mailing list, then please send it
379 to perl5-security-report@perl.org. This points to a closed subscription
380 unarchived mailing list, which includes all the core committers, who will be
381 able to help assess the impact of issues, figure out a resolution, and help
382 co-ordinate the release of patches to mitigate or fix the problem across all
383 platforms on which Perl is supported. Please only use this address for
384 security issues in the Perl core, not for modules independently distributed on
389 The F<Changes> file for an explanation of how to view exhaustive details on
392 The F<INSTALL> file for how to build Perl.
394 The F<README> file for general stuff.
396 The F<Artistic> and F<Copying> files for copyright information.