5 [ this is a template for a new perldelta file. Any text flagged as
6 XXX needs to be processed before release. ]
8 perldelta - what is new for perl v5.17.3
12 This document describes differences between the 5.17.2 release and
15 If you are upgrading from an earlier release such as 5.17.1, first read
16 L<perl5172delta>, which describes differences between 5.17.1 and
21 XXX Any important notices here
23 =head1 Core Enhancements
25 XXX New core language features go here. Summarise user-visible core language
26 enhancements. Particularly prominent performance optimisations could go
27 here, but most should go in the L</Performance Enhancements> section.
29 [ List each enhancement as a =head2 entry ]
33 XXX Any security-related notices go here. In particular, any security
34 vulnerabilities closed should be noted here rather than in the
35 L</Selected Bug Fixes> section.
37 [ List each security issue as a =head2 entry ]
39 =head1 Incompatible Changes
41 [ List each incompatible change as a =head2 entry ]
43 =head2 C<$ENV{foo} = undef> deletes value from environ, like C<delete $ENV{foo}>
45 This facilitates use of C<local()> with C<%ENV> entries. In previous
46 versions of Perl, C<undef> was converted to the empty string.
48 =head2 Defined values stored in environment are forced to byte strings
50 A value stored in an environment variable has always been stringified. In
51 this release, it is converted to be only a byte string. First, it is forced
52 to be a only a string. Then if the string is utf8 and the equivalent of
53 C<utf8::downgrade> works, that result is used; otherwise, the equivalent of
54 C<utf8::encode> is used, and a warning is issued about wide characters
59 XXX Any deprecated features, syntax, modules etc. should be listed here.
60 In particular, deprecated modules should be listed here even if they are
61 listed as an updated module in the L</Modules and Pragmata> section.
63 [ List each deprecation as a =head2 entry ]
65 =head1 Performance Enhancements
67 XXX Changes which enhance performance without changing behaviour go here. There
68 may well be none in a stable release.
70 [ List each enhancement as a =item entry ]
80 =head1 Modules and Pragmata
82 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
83 go here. If Module::CoreList is updated, generate an initial draft of the
84 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
85 entries to STDOUT. Results can be pasted in place of the '=head2' entries
86 below. A paragraph summary for important changes should then be added by hand.
87 In an ideal world, dual-life modules would have a F<Changes> file that could be
90 [ Within each section, list entries as a =item entry ]
92 =head2 New Modules and Pragmata
102 =head2 Updated Modules and Pragmata
108 L<B> has been upgraded from version 1.36 to version 1.37. All C<CVf_*> and
109 C<GVf_*> and more SV-related flag values are now provided as constants in
110 the C<B::> namespace and available for export. The default export list has
115 =head2 Removed Modules and Pragmata
127 XXX Changes to files in F<pod/> go here. Consider grouping entries by
128 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
130 =head2 New Documentation
132 XXX Changes which create B<new> files in F<pod/> go here.
136 XXX Description of the purpose of the new file here
138 =head2 Changes to Existing Documentation
140 XXX Changes which significantly change existing files in F<pod/> go here.
141 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
150 XXX Description of the change here
156 The following additions or changes have been made to diagnostic output,
157 including warnings and fatal error messages. For the complete list of
158 diagnostic messages, see L<perldiag>.
160 XXX New or changed warnings emitted by the core's C<C> code go here. Also
161 include any changes in L<perldiag> that reconcile it to the C<C> code.
163 [ Within each section, list entries as a =item entry that links to perldiag,
168 L<Invalid version object|perldiag/"Invalid version object">
171 =head2 New Diagnostics
173 XXX Newly added diagnostic messages go here
179 Attempts to put wide characters into environment variables via %ENV provoke
180 the warning "Wide character in setenv".
190 XXX L<message|perldiag/"message">
200 XXX L<message|perldiag/"message">
204 =head2 Changes to Existing Diagnostics
206 XXX Changes (i.e. rewording) of diagnostic messages go here
212 XXX Describe change here
216 =head1 Utility Changes
218 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
219 here. Most of these are built within the directories F<utils> and F<x2p>.
221 [ List utility changes as a =head3 entry for each utility and =item
222 entries for each change
223 Use L<XXX> with program names to get proper documentation linking. ]
235 =head1 Configuration and Compilation
237 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
238 go here. Any other changes to the Perl build process should be listed here.
239 However, any platform-specific changes should be listed in the
240 L</Platform Support> section, instead.
242 [ List changes as a =item entry ].
254 XXX Any significant changes to the testing of a freshly built perl should be
255 listed here. Changes which create B<new> files in F<t/> go here as do any
256 large changes to the testing harness (e.g. when parallel testing was added).
257 Changes to existing files in F<t/> aren't worth summarising, although the bugs
258 that they represent may be covered elsewhere.
260 [ List each test improvement as a =item entry ]
270 =head1 Platform Support
272 XXX Any changes to platform support should be listed in the sections below.
274 [ Within the sections, list each platform as a =item entry with specific
275 changes as paragraphs below it. ]
279 XXX List any platforms that this version of perl compiles on, that previous
280 versions did not. These will either be enabled by new files in the F<hints/>
281 directories, or new subdirectories and F<README> files at the top level of the
286 =item XXX-some-platform
292 =head2 Discontinued Platforms
294 XXX List any platforms that this version of perl no longer compiles on.
298 =item XXX-some-platform
304 =head2 Platform-Specific Notes
306 XXX List any changes for specific platforms. This could include configuration
307 and compilation changes or changes in portability/compatibility. However,
308 changes within modules for platforms should generally be listed in the
309 L</Modules and Pragmata> section.
313 =item XXX-some-platform
319 =head1 Internal Changes
321 XXX Changes which affect the interface available to C<XS> code go here.
322 Other significant internal changes for future core maintainers should
325 [ List each change as a =item entry ]
335 =head1 Selected Bug Fixes
337 XXX Important bug fixes in the core language are summarised here.
338 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
339 L</Modules and Pragmata>.
341 [ List each fix as a =item entry ]
347 C<\w> now matches the code points U+200C (ZERO WIDTH NON-JOINER) and
348 U+200D (ZERO WIDTH JOINER). C<\W> no longer matches these. This change
349 is because Unicode corrected their definition of what C<\w> should match.
353 C<dump LABEL> no longer leaks its label.
357 =head1 Known Problems
359 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
360 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
361 platform specific bugs also go here.
363 [ List each fix as a =item entry ]
375 XXX If any significant core contributor has died, we've added a short obituary
378 =head1 Acknowledgements
380 XXX Generate this with:
382 perl Porting/acknowledgements.pl v5.17.2..HEAD
384 =head1 Reporting Bugs
386 If you find what you think is a bug, you might check the articles
387 recently posted to the comp.lang.perl.misc newsgroup and the perl
388 bug database at http://rt.perl.org/perlbug/ . There may also be
389 information at http://www.perl.org/ , the Perl Home Page.
391 If you believe you have an unreported bug, please run the L<perlbug>
392 program included with your release. Be sure to trim your bug down
393 to a tiny but sufficient test case. Your bug report, along with the
394 output of C<perl -V>, will be sent off to perlbug@perl.org to be
395 analysed by the Perl porting team.
397 If the bug you are reporting has security implications, which make it
398 inappropriate to send to a publicly archived mailing list, then please send
399 it to perl5-security-report@perl.org. This points to a closed subscription
400 unarchived mailing list, which includes
401 all the core committers, who will be able
402 to help assess the impact of issues, figure out a resolution, and help
403 co-ordinate the release of patches to mitigate or fix the problem across all
404 platforms on which Perl is supported. Please only use this address for
405 security issues in the Perl core, not for modules independently
410 The F<Changes> file for an explanation of how to view exhaustive details
413 The F<INSTALL> file for how to build Perl.
415 The F<README> file for general stuff.
417 The F<Artistic> and F<Copying> files for copyright information.