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perldelta for 1f039d60d3 (last $foo)
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1=encoding utf8
2
3=head1 NAME
4
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5[ this is a template for a new perldelta file. Any text flagged as
6XXX needs to be processed before release. ]
417a992d 7
4eabcf70 8perldelta - what is new for perl v5.17.3
e128ab2c 9
4eabcf70 10=head1 DESCRIPTION
6db9054f 11
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12This document describes differences between the 5.17.2 release and
13the 5.17.3 release.
6db9054f 14
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15If you are upgrading from an earlier release such as 5.17.1, first read
16L<perl5172delta>, which describes differences between 5.17.1 and
175.17.2.
ef7131e9 18
4eabcf70 19=head1 Notice
ff3f295c 20
4eabcf70 21XXX Any important notices here
95c6c5c5 22
4eabcf70 23=head1 Core Enhancements
95c6c5c5 24
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25XXX New core language features go here. Summarise user-visible core language
26enhancements. Particularly prominent performance optimisations could go
27here, but most should go in the L</Performance Enhancements> section.
4c77591b 28
4eabcf70 29[ List each enhancement as a =head2 entry ]
c506fc7e 30
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31=head2 Computed Labels
32
33The loop controls C<next>, C<last> and C<redo>, and the special C<dump>
34operator, now allow arbitrary expressions to be used to compute labels at
35run time. Previously, any argument that was not a constant was treated as
36the empty string.
37
4eabcf70 38=head1 Security
36ab1671 39
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40XXX Any security-related notices go here. In particular, any security
41vulnerabilities closed should be noted here rather than in the
42L</Selected Bug Fixes> section.
36ab1671 43
4eabcf70 44[ List each security issue as a =head2 entry ]
36ab1671 45
4eabcf70 46=head1 Incompatible Changes
df2c1bb8 47
613c63b4 48[ List each incompatible change as a =head2 entry ]
df2c1bb8 49
613c63b4 50=head2 C<$ENV{foo} = undef> deletes value from environ, like C<delete $ENV{foo}>
df2c1bb8 51
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52This facilitates use of C<local()> with C<%ENV> entries. In previous
53versions of Perl, C<undef> was converted to the empty string.
54
55=head2 Defined values stored in environment are forced to byte strings
56
57A value stored in an environment variable has always been stringified. In
58this release, it is converted to be only a byte string. First, it is forced
59to be a only a string. Then if the string is utf8 and the equivalent of
60C<utf8::downgrade> works, that result is used; otherwise, the equivalent of
61C<utf8::encode> is used, and a warning is issued about wide characters
62(L</Diagnostics>).
7ab2ea42 63
4eabcf70 64=head1 Deprecations
7ab2ea42 65
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66XXX Any deprecated features, syntax, modules etc. should be listed here.
67In particular, deprecated modules should be listed here even if they are
68listed as an updated module in the L</Modules and Pragmata> section.
7ab2ea42 69
4eabcf70 70[ List each deprecation as a =head2 entry ]
7ab2ea42 71
4eabcf70 72=head1 Performance Enhancements
3be135d8 73
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74XXX Changes which enhance performance without changing behaviour go here. There
75may well be none in a stable release.
3be135d8 76
4eabcf70 77[ List each enhancement as a =item entry ]
6db9054f 78
4eabcf70 79=over 4
6db9054f 80
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81=item *
82
4eabcf70 83XXX
7ca04d94 84
e96e0834 85=back
c506fc7e 86
4eabcf70 87=head1 Modules and Pragmata
95c6c5c5 88
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89XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
90go here. If Module::CoreList is updated, generate an initial draft of the
91following sections using F<Porting/corelist-perldelta.pl>, which prints stub
92entries to STDOUT. Results can be pasted in place of the '=head2' entries
93below. A paragraph summary for important changes should then be added by hand.
94In an ideal world, dual-life modules would have a F<Changes> file that could be
95cribbed.
95c6c5c5 96
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97[ Within each section, list entries as a =item entry ]
98
99=head2 New Modules and Pragmata
95c6c5c5 100
e96e0834 101=over 4
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102
103=item *
104
4eabcf70 105XXX
95c6c5c5 106
e96e0834 107=back
95c6c5c5 108
4eabcf70 109=head2 Updated Modules and Pragmata
95c6c5c5 110
e96e0834 111=over 4
95c6c5c5 112
95c6c5c5
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113=item *
114
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115L<B> has been upgraded from version 1.36 to version 1.37. All C<CVf_*> and
116C<GVf_*> and more SV-related flag values are now provided as constants in
117the C<B::> namespace and available for export. The default export list has
118not changed.
b8a55fe7 119
e96e0834 120=back
95c6c5c5 121
4eabcf70 122=head2 Removed Modules and Pragmata
95c6c5c5 123
e96e0834 124=over 4
95c6c5c5 125
95c6c5c5
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126=item *
127
4eabcf70 128XXX
4f85bc45 129
4eabcf70 130=back
72267260 131
4eabcf70 132=head1 Documentation
72267260 133
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134XXX Changes to files in F<pod/> go here. Consider grouping entries by
135file and be sure to link to the appropriate page, e.g. L<perlfunc>.
4f85bc45 136
4eabcf70 137=head2 New Documentation
7d101ed1 138
4eabcf70 139XXX Changes which create B<new> files in F<pod/> go here.
e013ada0 140
4eabcf70 141=head3 L<XXX>
4f85bc45 142
4eabcf70 143XXX Description of the purpose of the new file here
e013ada0 144
4eabcf70 145=head2 Changes to Existing Documentation
95c6c5c5 146
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147XXX Changes which significantly change existing files in F<pod/> go here.
148However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
149section.
95c6c5c5 150
be28af6e 151=head3 L<perlfunc>, L<perlop>
95c6c5c5 152
e96e0834 153=over 4
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154
155=item *
156
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157Loop control verbs (C<dump>, C<goto>, C<next>, C<last> and C<redo>) have
158always had the same precedence as assignment operators, but this was never
159documented until now.
95c6c5c5 160
e96e0834 161=back
95c6c5c5 162
4eabcf70 163=head1 Diagnostics
05c8f9ed 164
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165The following additions or changes have been made to diagnostic output,
166including warnings and fatal error messages. For the complete list of
167diagnostic messages, see L<perldiag>.
ceb0881c 168
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169XXX New or changed warnings emitted by the core's C<C> code go here. Also
170include any changes in L<perldiag> that reconcile it to the C<C> code.
0998713f 171
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172[ Within each section, list entries as a =item entry that links to perldiag,
173 e.g.
112b6866 174
4eabcf70 175 =item *
112b6866 176
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177 L<Invalid version object|perldiag/"Invalid version object">
178]
42d72fc5 179
4eabcf70 180=head2 New Diagnostics
42d72fc5 181
4eabcf70 182XXX Newly added diagnostic messages go here
8e125188 183
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184=over 4
185
186=item *
187
188Attempts to put wide characters into environment variables via %ENV provoke
189the warning "Wide character in setenv".
190
191=back
192
4eabcf70 193=head3 New Errors
8e125188 194
e96e0834 195=over 4
e128ab2c 196
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197=item *
198
4eabcf70 199XXX L<message|perldiag/"message">
16e4fcbf 200
4eabcf70 201=back
e2f0c3bb 202
4eabcf70 203=head3 New Warnings
90519d0f 204
4eabcf70 205=over 4
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206
207=item *
208
4eabcf70 209XXX L<message|perldiag/"message">
90519d0f 210
61174fb5 211=back
422287bf 212
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213=head2 Changes to Existing Diagnostics
214
215XXX Changes (i.e. rewording) of diagnostic messages go here
2de6ba8d 216
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217=over 4
218
219=item *
220
4eabcf70 221XXX Describe change here
e128ab2c 222
4eabcf70 223=back
8b1adbab 224
4eabcf70 225=head1 Utility Changes
8b1adbab 226
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227XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
228here. Most of these are built within the directories F<utils> and F<x2p>.
83f29afa 229
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230[ List utility changes as a =head3 entry for each utility and =item
231entries for each change
232Use L<XXX> with program names to get proper documentation linking. ]
83f29afa 233
4eabcf70 234=head3 L<XXX>
0938f143 235
4eabcf70 236=over 4
0938f143 237
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238=item *
239
4eabcf70 240XXX
7a251f7a 241
4eabcf70 242=back
7a251f7a 243
4eabcf70 244=head1 Configuration and Compilation
21247d85 245
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246XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
247go here. Any other changes to the Perl build process should be listed here.
248However, any platform-specific changes should be listed in the
249L</Platform Support> section, instead.
21247d85 250
4eabcf70 251[ List changes as a =item entry ].
2e4f8b82 252
4eabcf70 253=over 4
c95d4104 254
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255=item *
256
4eabcf70 257XXX
788505db 258
4eabcf70 259=back
2c2b9cf4 260
4eabcf70 261=head1 Testing
3cd56aaa 262
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263XXX Any significant changes to the testing of a freshly built perl should be
264listed here. Changes which create B<new> files in F<t/> go here as do any
265large changes to the testing harness (e.g. when parallel testing was added).
266Changes to existing files in F<t/> aren't worth summarising, although the bugs
267that they represent may be covered elsewhere.
3cd56aaa 268
4eabcf70 269[ List each test improvement as a =item entry ]
3cd56aaa 270
4eabcf70 271=over 4
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272
273=item *
274
4eabcf70 275XXX
3cd56aaa 276
4eabcf70 277=back
3cd56aaa 278
4eabcf70 279=head1 Platform Support
3cd56aaa 280
4eabcf70 281XXX Any changes to platform support should be listed in the sections below.
3cd56aaa 282
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283[ Within the sections, list each platform as a =item entry with specific
284changes as paragraphs below it. ]
3cd56aaa 285
4eabcf70 286=head2 New Platforms
3cd56aaa 287
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288XXX List any platforms that this version of perl compiles on, that previous
289versions did not. These will either be enabled by new files in the F<hints/>
290directories, or new subdirectories and F<README> files at the top level of the
291source tree.
3cd56aaa 292
4eabcf70 293=over 4
3cd56aaa 294
4eabcf70 295=item XXX-some-platform
3cd56aaa 296
4eabcf70 297XXX
c0c19433 298
4eabcf70 299=back
c0c19433 300
4eabcf70 301=head2 Discontinued Platforms
7ab2ea42 302
4eabcf70 303XXX List any platforms that this version of perl no longer compiles on.
7ab2ea42 304
4eabcf70 305=over 4
7ab2ea42 306
4eabcf70 307=item XXX-some-platform
7ab2ea42 308
4eabcf70 309XXX
90519d0f 310
4eabcf70 311=back
90519d0f 312
4eabcf70 313=head2 Platform-Specific Notes
90519d0f 314
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315XXX List any changes for specific platforms. This could include configuration
316and compilation changes or changes in portability/compatibility. However,
317changes within modules for platforms should generally be listed in the
318L</Modules and Pragmata> section.
90519d0f 319
4eabcf70 320=over 4
90519d0f 321
4eabcf70 322=item XXX-some-platform
90519d0f 323
4eabcf70 324XXX
90519d0f 325
4eabcf70 326=back
90519d0f 327
4eabcf70 328=head1 Internal Changes
90519d0f 329
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330XXX Changes which affect the interface available to C<XS> code go here.
331Other significant internal changes for future core maintainers should
332be noted as well.
90519d0f 333
4eabcf70 334[ List each change as a =item entry ]
90519d0f 335
4eabcf70 336=over 4
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337
338=item *
339
4eabcf70 340XXX
90519d0f 341
4eabcf70 342=back
90519d0f 343
4eabcf70 344=head1 Selected Bug Fixes
90519d0f 345
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346XXX Important bug fixes in the core language are summarised here.
347Bug fixes in files in F<ext/> and F<lib/> are best summarised in
348L</Modules and Pragmata>.
90519d0f 349
4eabcf70 350[ List each fix as a =item entry ]
90519d0f 351
4eabcf70 352=over 4
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353
354=item *
355
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356C<\w> now matches the code points U+200C (ZERO WIDTH NON-JOINER) and
357U+200D (ZERO WIDTH JOINER). C<\W> no longer matches these. This change
358is because Unicode corrected their definition of what C<\w> should match.
90519d0f 359
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360=item *
361
362C<dump LABEL> no longer leaks its label.
363
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364=item *
365
366Constant folding no longer changes the behaviour of functions like C<stat>
367and C<truncate> that can take either filenames or handles.
368C<stat 1 ? foo : bar> nows treats its argument as a file name (since it is
369an arbitrary expression), rather than the handle "foo".
370
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371=item *
372
373C<truncate FOO, $len> no longer falls back to treating "FOO" as a file name
374if the filehandle has been deleted. This was broken in Perl 5.16.0.
375
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376=item *
377
378Subroutine redefinitions after sub-to-glob and glob-to-glob assignments no
379longer cause double frees or panic messages.
380
4eabcf70 381=back
90519d0f 382
4eabcf70 383=head1 Known Problems
b8a55fe7 384
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385XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
386tests that had to be C<TODO>ed for the release would be noted here. Unfixed
387platform specific bugs also go here.
b8a55fe7 388
4eabcf70 389[ List each fix as a =item entry ]
b8a55fe7 390
4eabcf70 391=over 4
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392
393=item *
394
4eabcf70 395XXX
b8a55fe7 396
4eabcf70 397=back
5073ffbd 398
4eabcf70 399=head1 Obituary
5073ffbd 400
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401XXX If any significant core contributor has died, we've added a short obituary
402here.
e128ab2c 403
61174fb5 404=head1 Acknowledgements
d5dc7001 405
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406XXX Generate this with:
407
408 perl Porting/acknowledgements.pl v5.17.2..HEAD
29cf780c 409
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410=head1 Reporting Bugs
411
412If you find what you think is a bug, you might check the articles
52deee2e 413recently posted to the comp.lang.perl.misc newsgroup and the perl
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414bug database at http://rt.perl.org/perlbug/ . There may also be
415information at http://www.perl.org/ , the Perl Home Page.
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416
417If you believe you have an unreported bug, please run the L<perlbug>
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418program included with your release. Be sure to trim your bug down
419to a tiny but sufficient test case. Your bug report, along with the
420output of C<perl -V>, will be sent off to perlbug@perl.org to be
421analysed by the Perl porting team.
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422
423If the bug you are reporting has security implications, which make it
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424inappropriate to send to a publicly archived mailing list, then please send
425it to perl5-security-report@perl.org. This points to a closed subscription
426unarchived mailing list, which includes
427all the core committers, who will be able
428to help assess the impact of issues, figure out a resolution, and help
429co-ordinate the release of patches to mitigate or fix the problem across all
430platforms on which Perl is supported. Please only use this address for
431security issues in the Perl core, not for modules independently
432distributed on CPAN.
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433
434=head1 SEE ALSO
435
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436The F<Changes> file for an explanation of how to view exhaustive details
437on what changed.
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438
439The F<INSTALL> file for how to build Perl.
440
441The F<README> file for general stuff.
442
443The F<Artistic> and F<Copying> files for copyright information.
444
445=cut