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1=encoding utf8
2
3=head1 NAME
4
19718730 5perldelta - what is new for perl v5.17.9
e128ab2c 6
4eabcf70 7=head1 DESCRIPTION
6db9054f 8
19718730 9This document describes differences between the 5.17.8 release and the 5.17.9
e08634c5 10release.
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12If you are upgrading from an earlier release such as 5.17.7, first read
13L<perl5178delta>, which describes differences between 5.17.7 and 5.17.8.
14
6253ee75 15=head1 Core Enhancements
dd271d7a 16
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17=head2 Interpolations now Accepted in Regular Expression Set Operations
18
19Perl v5.17.8 introduced L<regular expression set operations|perlre/(?[ ])>.
20They have now been expanded to allow the interpolation of a
21previously-compiled set into a bigger set, like this:
22
ea5a2f13 23 my $thai_or_lao = qr/\p{Thai} + \p{Lao}/;
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24 ...
25 qr/(?[ \p{Digit} & $thai_or_lao ])/;
26
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27=head1 Incompatible Changes
28
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29=head2 C<$ENV{foo} = undef> no longer deletes value from environ
30
315.17.3 Introduced a change where assiging C<undef> to an C<%ENV> key was equivalent
32to C<delete $ENV{foo}>.
33
34This release reverts that change.
35
0e55f0d7 36=head1 Deprecations
3ef6ec90 37
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38The deprecation of lexical C<$_> in 5.17.7 has been commuted. The feature
39is now marked experimental.
d1e59372 40
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41=head2 Deprecated pragma
42
43=over
44
45=item L<encoding>
46
47This module is deprecated under perl 5.18. It uses a mechanism provided by
48perl that is deprecated under 5.18 and higher, and may be removed in a
49future version.
50
51=back
52
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53=head2 Deprecated Modules
54
55The following modules will be removed from the core distribution in a
56future release, and should be installed from CPAN instead. Distributions
57on CPAN which require these should add them to their prerequisites. The
58core versions of these modules C<warnings> will issue a deprecation warning.
59
60You can silence these deprecation warnings by installing the modules
61in question from CPAN.
62
63=over
64
65=item L<Archive::Extract>
66
67=item L<B::Lint>
68
69=item L<B::Lint::Debug>
70
71=item L<CPANPLUS>
72
73=item L<CPANPLUS::Backend>
74
75=item L<CPANPLUS::Backend::RV>
76
77=item L<CPANPLUS::Config>
78
79=item L<CPANPLUS::Config::HomeEnv>
80
81=item L<CPANPLUS::Configure>
82
9150e781 83=item C<CPANPLUS::Configure::Setup>
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84
85=item L<CPANPLUS::Dist>
86
87=item L<CPANPLUS::Dist::Autobundle>
88
89=item L<CPANPLUS::Dist::Base>
90
91=item L<CPANPLUS::Dist::Build>
92
93=item L<CPANPLUS::Dist::Build::Constants>
94
95=item L<CPANPLUS::Dist::MM>
96
97=item L<CPANPLUS::Dist::Sample>
98
99=item L<CPANPLUS::Error>
100
101=item L<CPANPLUS::Internals>
102
9150e781 103=item C<CPANPLUS::Internals::Constants>
3f01b192 104
9150e781 105=item C<CPANPLUS::Internals::Constants::Report>
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106
107=item L<CPANPLUS::Internals::Extract>
108
109=item L<CPANPLUS::Internals::Fetch>
110
111=item L<CPANPLUS::Internals::Report>
112
113=item L<CPANPLUS::Internals::Search>
114
115=item L<CPANPLUS::Internals::Source>
116
117=item L<CPANPLUS::Internals::Source::Memory>
118
119=item L<CPANPLUS::Internals::Source::SQLite>
120
9150e781 121=item C<CPANPLUS::Internals::Source::SQLite::Tie>
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122
123=item L<CPANPLUS::Internals::Utils>
124
9150e781 125=item C<CPANPLUS::Internals::Utils::Autoflush>
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126
127=item L<CPANPLUS::Module>
128
129=item L<CPANPLUS::Module::Author>
130
131=item L<CPANPLUS::Module::Author::Fake>
132
133=item L<CPANPLUS::Module::Checksums>
134
135=item L<CPANPLUS::Module::Fake>
136
9150e781 137=item C<CPANPLUS::Module::Signature>
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138
139=item L<CPANPLUS::Selfupdate>
140
141=item L<CPANPLUS::Shell>
142
143=item L<CPANPLUS::Shell::Classic>
144
145=item L<CPANPLUS::Shell::Default>
146
147=item L<CPANPLUS::Shell::Default::Plugins::CustomSource>
148
149=item L<CPANPLUS::Shell::Default::Plugins::Remote>
150
151=item L<CPANPLUS::Shell::Default::Plugins::Source>
152
153=item L<Devel::InnerPackage>
154
155=item L<Log::Message>
156
157=item L<Log::Message::Config>
158
159=item L<Log::Message::Handlers>
160
161=item L<Log::Message::Item>
162
163=item L<Log::Message::Simple>
164
165=item L<Module::Pluggable>
166
167=item L<Module::Pluggable::Object>
168
169=item L<Object::Accessor>
170
171=item L<Term::UI>
172
173=item L<Term::UI::History>
174
175=back
176
177=head3 Deprecated Utilities
178
179The following utilities will be removed from the core distribution in a
180future release as their associated modules have been deprecated. They
181will remain available with the applicable CPAN distribution.
182
183=over
184
185=item L<cpanp>
186
187Included with L<CPANPLUS>.
188
9150e781 189=item C<cpanp-run-perl>
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190
191Included with L<CPANPLUS>.
192
193=item L<cpan2dist>
194
195Included with L<CPANPLUS>.
196
197=item L<pod2latex>
198
199The L<Pod::LaTeX> module was deprecated with 5.17.8.
200
201=back
202
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203=head2 Five additional characters should be escaped in patterns with C</x>
204
205When a regular expression pattern is compiled with C</x>, Perl treats 6
206characters as white space to ignore, such as SPACE and TAB. However,
207Unicode recommends 11 characters be treated thusly. In preparation to
208conforming with this in a future Perl version, in the meantime, use of
209any of the missing characters will raise a deprecation warning, unless
210turned off. The five characters are:
211U+0085 NEXT LINE,
212U+200E LEFT-TO-RIGHT MARK,
213U+200F RIGHT-TO-LEFT MARK,
214U+2028 LINE SEPARATOR,
215and
216U+2029 PARAGRAPH SEPARATOR.
217
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218=head1 Modules and Pragmata
219
220XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
221go here. If Module::CoreList is updated, generate an initial draft of the
222following sections using F<Porting/corelist-perldelta.pl>, which prints stub
223entries to STDOUT. Results can be pasted in place of the '=head2' entries
224below. A paragraph summary for important changes should then be added by hand.
225In an ideal world, dual-life modules would have a F<Changes> file that could be
226cribbed.
227
228[ Within each section, list entries as a =item entry ]
229
230=head2 New Modules and Pragmata
751611d4 231
6253ee75 232=over 4
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233
234=item *
235
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236L<Config::Perl::V> version 0.16 has been added as a dual-lifed module.
237It provides structured data retrieval of C<perl -V> output including
238information only known to the C<perl> binary and not available via L<Config>.
751611d4 239
19718730 240=back
86148eee 241
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242=head2 Updated Modules and Pragmata
243
244=over 4
7a7a10c7 245
e14ac59b 246=item *
7a7a10c7 247
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248L<Benchmark> has been upgraded from version 1.13 to 1.14.
249
250The "too few iterations" message is now a warning on STDERR
251instead of being output on STDOUT.
252
253=item *
254
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255L<Data::Dumper> has been upgraded from version 2.141 to 2.142.
256
257Additional tests were added in order to improve statement, branch, condition
258and subroutine coverage. On the basis of the coverage analysis, some of the
259internals of Dumper.pm were refactored. Almost all methods are now
260documented.
261
262=item *
263
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264L<File::Temp> has been upgraded from version 0.22 to 0.22_90
265
266Fixes various bugs involving directory removal. Defers unlinking tempfiles if
267the initial unlink fails, which fixes problems on NFS.
268
269=item *
270
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271L<PerlIO::scalar> has been upgraded from version 0.15 to 0.16.
272
273The buffer scalar supplied may now only contain code pounts 0xFF or
274lower. [perl #109828]
7a7a10c7 275
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276=back
277
19718730 278=head1 Documentation
11e375e0 279
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280=head2 Changes to Existing Documentation
281
b9214e65 282=head3 L<perlsec>
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283
284=over 4
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285
286=item *
287
b9214e65 288A syntax error was fixed in one of illustrative examples.
cb077ed2 289
5d8c8c8a 290=back
5f877a7f 291
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292=head1 Diagnostics
293
294The following additions or changes have been made to diagnostic output,
295including warnings and fatal error messages. For the complete list of
296diagnostic messages, see L<perldiag>.
1ea91bbe 297
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298=head2 New Diagnostics
299
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300=head3 New Warnings
301
302=over 4
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303
304=item *
305
d2d1e842 306Strings with code points over 0xFF may not be mapped into in-memory file handles
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307
308=back
309
310=head2 Changes to Existing Diagnostics
311
19718730 312=over 4
e14ac59b 313
6253ee75 314=item *
8b877d20 315
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316The warnings for \b{ and \B{ were added in the 5.17 series; they are a
317deprecation warning which should be turned off by that category. One
318should not have to turn off regular regexp warnings as well to get rid
319of these.
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320
321=back
322
323=head1 Utility Changes
324
5bf072ac 325=head3 L<corelist>
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326
327=over 4
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328
329=item *
330
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331Added C<--feature> switch which lists the first version bundle of each
332named feature given.
e078d89d 333
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334=item *
335
336Added C<--upstream> switch which shows if the given module
337is primarily maintained in perl core or on CPAN and bug tracker URL.
338
6253ee75 339=back
e078d89d 340
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341=head1 Configuration and Compilation
342
6253ee75 343=over 4
e078d89d 344
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345=item *
346
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347Added C<useversionedarchname> option to Configure
348
349When set, it includes 'api_versionstring' in 'archname'. E.g.
350x86_64-linux-5.13.6-thread-multi. It is unset by default.
351
352This feature was requested by Tim Bunce, who observed that
353INSTALL_BASE creates a library structure that does not
354differentiate by perl version. Instead, it places architecture
355specific files in "$install_base/lib/perl5/$archname". This makes
356it difficult to use a common INSTALL_BASE library path with
357multiple versions of perl.
358
359By setting -Duseversionedarchname, the $archname will be
360distinct for architecture *and* API version, allowing mixed use of
361INSTALL_BASE.
362
363=item *
364
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365Configure will honour the external C<MAILDOMAIN> environment variable, if set.
366
367=item *
368
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369C<installman> no longer ignores the silent option
370
371=item *
372
8e8f9da4 373Both C<META.yml> and C<META.json> files are now included in the distribution.
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374
375=back
376
377=head1 Testing
378
19718730 379=over 4
e14ac59b 380
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381=item *
382
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383Enable perl core tests to pass when locale support is not available.
384
385use L<locale> - this will now die if $Config{d_setlocale} is not true.
386All tests that use L<locale> will skip if $Config{d_setlocale} is not true.
387This enables us to pass tests on Android which uses ICU instead of locales.
fdea6f98 388
6253ee75 389=back
7cf3104f 390
6253ee75 391=head1 Platform Support
7cf3104f 392
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393=head2 Platform-Specific Notes
394
19718730 395=over 4
6e50262c 396
480c6724 397=item VMS
6e50262c 398
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399The character set for Extended Filename Syntax (EFS) is now enabled by default on
400VMS. Among other things, this provides better handling of dots in directory names,
401multiple dots in filenames,and spaces in filenames. To obtain the old behavior,
402set the logical name C<DECC$EFS_CHARSET> to C<DISABLE>.
785fb813 403
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404=item MidnightBSD
405
406C<libc_r> was removed from recent versions of MidnightBSD and older versions
407work better with C<pthread>. Threading is now enabled using C<pthread> which
408corrects build errors with threading enabled on 0.4-CURRENT.
409
0e55f0d7 410=back
785fb813 411
0e55f0d7 412=head1 Internal Changes
f5778209 413
6253ee75 414=over 4
f5778209 415
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416=item *
417
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418Synonyms for the misleadingly named C<av_len()> has been created:
419C<av_top_index()> and C<av_tindex>. All three of these return the
420number of the highest index in the array, not the number of elements it
421contains. (The name C<av_top> which was introduced in Perl v.5.17.8 has
422been removed.)
423
6253ee75 424=back
216cf7fc 425
6253ee75 426=head1 Selected Bug Fixes
216cf7fc 427
19718730 428=over 4
216cf7fc 429
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430=item *
431
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432-DPERL_GLOBAL_STRUCT builds now free the global struct B<after>
433they've finished using it.
d76c0f4b 434
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435=item *
436
437A trailing '/' on a path in @INC will no longer have an additional '/' appended.
438
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439=item *
440
441The C<:crlf> layer now works when unread data doesn't fit into its own
442buffer. [perl #112244].
443
444=item *
445
446C<ungetc()> now handles UTF-8 encoded data. [perl #116322].
447
6253ee75 448=back
6c042f06 449
19718730 450=head1 Acknowledgements
f5b73711 451
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452Perl 5.17.9 represents approximately 4 weeks of development since Perl 5.17.8
453and contains approximately 42,000 lines of changes across 510 files from 35
454authors.
455
456Perl continues to flourish into its third decade thanks to a vibrant community
457of users and developers. The following people are known to have contributed the
458improvements that became Perl 5.17.9:
459
460!, Aaron Crane, Alan Haggai Alavi, Alexandr Ciornii, Andy Dougherty, Brad
461Gilbert, Chris 'BinGOs' Williams, Christian Hansen, Craig A. Berry, Dagfinn
462Ilmari Mannsåker, Daniel Dragan, Dave Rolsky, David Golden, David Mitchell,
463Father Chrysostomos, H.Merijn Brand, James E Keenan, Jan Dubois, Jerry D.
464Hedden, Jess Robinson, Karl Williamson, Kent Fredric, Leon Timmermans, Lucas
465Holt, Matthew Horsfall, Nicholas Clark, Peter Martini, Rafael Garcia-Suarez,
466Ricardo Signes, Smylers, Steffen Müller, Steve Hay, Thomas Sibley, Tobias
467Leich, Tony Cook.
468
469The list above is almost certainly incomplete as it is automatically generated
470from version control history. In particular, it does not include the names of
471the (very much appreciated) contributors who reported issues to the Perl bug
472tracker.
473
474Many of the changes included in this version originated in the CPAN modules
475included in Perl's core. We're grateful to the entire CPAN community for
476helping Perl to flourish.
477
478For a more complete list of all of Perl's historical contributors, please see
479the F<AUTHORS> file in the Perl source distribution.
f5b73711 480
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481=head1 Reporting Bugs
482
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483If you find what you think is a bug, you might check the articles recently
484posted to the comp.lang.perl.misc newsgroup and the perl bug database at
485http://rt.perl.org/perlbug/ . There may also be information at
486http://www.perl.org/ , the Perl Home Page.
44691e6f 487
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488If you believe you have an unreported bug, please run the L<perlbug> program
489included with your release. Be sure to trim your bug down to a tiny but
490sufficient test case. Your bug report, along with the output of C<perl -V>,
491will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
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492
493If the bug you are reporting has security implications, which make it
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494inappropriate to send to a publicly archived mailing list, then please send it
495to perl5-security-report@perl.org. This points to a closed subscription
496unarchived mailing list, which includes all the core committers, who will be
497able to help assess the impact of issues, figure out a resolution, and help
f9001595 498co-ordinate the release of patches to mitigate or fix the problem across all
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499platforms on which Perl is supported. Please only use this address for
500security issues in the Perl core, not for modules independently distributed on
501CPAN.
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502
503=head1 SEE ALSO
504
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505The F<Changes> file for an explanation of how to view exhaustive details on
506what changed.
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507
508The F<INSTALL> file for how to build Perl.
509
510The F<README> file for general stuff.
511
512The F<Artistic> and F<Copying> files for copyright information.
513
514=cut