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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. ]
27f00e3d 7
e96e0834 8perldelta - what is new for perl v5.17.2
417a992d 9
e96e0834 10=head1 DESCRIPTION
028c8719 11
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12This document describes differences between the 5.17.1 release and
13the 5.17.2 release.
028c8719 14
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15If you are upgrading from an earlier release such as 5.17.0, first read
16L<perl5171delta>, which describes differences between 5.17.0 and
175.17.1.
028c8719 18
e96e0834 19=head1 Notice
30608892 20
e96e0834 21XXX Any important notices here
e128ab2c 22
e96e0834 23=head1 Core Enhancements
e128ab2c 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.
fe3193b5 28
e96e0834 29[ List each enhancement as a =head2 entry ]
05c8f9ed 30
e96e0834 31=head1 Security
0da72d5e 32
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33XXX Any security-related notices go here. In particular, any security
34vulnerabilities closed should be noted here rather than in the
35L</Selected Bug Fixes> section.
0da72d5e 36
e96e0834 37[ List each security issue as a =head2 entry ]
0da72d5e 38
e96e0834 39=head1 Incompatible Changes
0da72d5e 40
e96e0834 41XXX For a release on a stable branch, this section aspires to be:
0da72d5e 42
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43 There are no changes intentionally incompatible with 5.XXX.XXX
44 If any exist, they are bugs, and we request that you submit a
45 report. See L</Reporting Bugs> below.
0da72d5e 46
e96e0834 47[ List each incompatible change as a =head2 entry ]
e2f0c3bb 48
e96e0834 49=head1 Deprecations
e2f0c3bb 50
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51XXX Any deprecated features, syntax, modules etc. should be listed here.
52In particular, deprecated modules should be listed here even if they are
53listed as an updated module in the L</Modules and Pragmata> section.
7d101ed1 54
e96e0834 55[ List each deprecation as a =head2 entry ]
7d101ed1 56
e96e0834 57=head1 Performance Enhancements
7d101ed1 58
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59XXX Changes which enhance performance without changing behaviour go here. There
60may well be none in a stable release.
7d101ed1 61
e96e0834 62[ List each enhancement as a =item entry ]
95ce428c 63
f9001595 64=over 4
75ff5956 65
2630d42b 66=item *
c11980ad 67
e96e0834 68XXX
53de3ff0 69
61174fb5 70=back
ef7131e9 71
61174fb5 72=head1 Modules and Pragmata
ef7131e9 73
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74XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
75go here. If Module::CoreList is updated, generate an initial draft of the
76following sections using F<Porting/corelist-perldelta.pl>, which prints stub
77entries to STDOUT. Results can be pasted in place of the '=head2' entries
78below. A paragraph summary for important changes should then be added by hand.
79In an ideal world, dual-life modules would have a F<Changes> file that could be
80cribbed.
5cefbec9 81
e96e0834 82[ Within each section, list entries as a =item entry ]
fbdb83f3 83
e96e0834 84=head2 New Modules and Pragmata
95c6c5c5 85
e96e0834 86=over 4
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87
88=item *
89
e96e0834 90XXX
95c6c5c5 91
e96e0834 92=back
ff3f295c 93
e96e0834 94=head2 Updated Modules and Pragmata
ff3f295c 95
e96e0834 96=over 4
95c6c5c5 97
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98=item *
99
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100L<File::stat> has been upgraded from version 1.06 to 1.07.
101
102Previously C<File::stat>'s overloaded C<-x> and C<-X> operators did not give
103the correct results for directories or executable files when running as
104root. They had been treating executable permissions for root just like for
105any other user, performing group membership tests I<etc> for files not owned
106by root. They now follow the correct Unix behaviour - for a directory they
107are always true, and for a file if any of the three execute permission bits
108are set then they report that root can execute the file. Perl's builtin
109C<-x> and C<-X> operators have always been correct.
c506fc7e 110
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111=item *
112
113L<Tie::StdHandle> has been upgraded from version 4.2 to 4.3.
114
115C<READ> now respects the offset argument to C<read> [perl #112826].
116
e96e0834 117=back
c506fc7e 118
e96e0834 119=head2 Removed Modules and Pragmata
c506fc7e 120
e96e0834 121=over 4
95c6c5c5 122
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123=item *
124
e96e0834 125XXX
95c6c5c5 126
e96e0834 127=back
95c6c5c5 128
e96e0834 129=head1 Documentation
95c6c5c5 130
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131XXX Changes to files in F<pod/> go here. Consider grouping entries by
132file and be sure to link to the appropriate page, e.g. L<perlfunc>.
95c6c5c5 133
e96e0834 134=head2 New Documentation
1c633914 135
e96e0834 136XXX Changes which create B<new> files in F<pod/> go here.
f558db2f 137
e96e0834 138=head3 L<XXX>
66aa79e2 139
e96e0834 140XXX Description of the purpose of the new file here
95c6c5c5 141
e96e0834 142=head2 Changes to Existing Documentation
95c6c5c5 143
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144XXX Changes which significantly change existing files in F<pod/> go here.
145However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
146section.
95c6c5c5 147
e96e0834 148=head3 L<XXX>
95c6c5c5 149
e96e0834 150=over 4
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151
152=item *
153
e96e0834 154XXX Description of the change here
95c6c5c5 155
e96e0834 156=back
95c6c5c5 157
e96e0834 158=head1 Diagnostics
95c6c5c5 159
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160The following additions or changes have been made to diagnostic output,
161including warnings and fatal error messages. For the complete list of
162diagnostic messages, see L<perldiag>.
95c6c5c5 163
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164XXX New or changed warnings emitted by the core's C<C> code go here. Also
165include any changes in L<perldiag> that reconcile it to the C<C> code.
71014848 166
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167[ Within each section, list entries as a =item entry that links to perldiag,
168 e.g.
71014848 169
e96e0834 170 =item *
95c6c5c5 171
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172 L<Invalid version object|perldiag/"Invalid version object">
173]
95c6c5c5 174
e96e0834 175=head2 New Diagnostics
95c6c5c5 176
e96e0834 177XXX Newly added diagnostic messages go here
95c6c5c5 178
e96e0834 179=head3 New Errors
95c6c5c5 180
e96e0834 181=over 4
95c6c5c5 182
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183=item *
184
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185L<Group name must start with a non-digit word character in regex; marked by <-- HERE in m/%s/|perldiag/"Group name must start with a non-digit word character in regex; marked by <-- HERE in m/%s/">
186
187This error has been added for C<(?&0)>, which is invalid. It used to
188produce an incomprehensible error message [perl #101666].
95c6c5c5 189
e96e0834 190=back
95c6c5c5 191
e96e0834 192=head3 New Warnings
95c6c5c5 193
e96e0834 194=over 4
95c6c5c5 195
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196=item *
197
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198C<chr()> now warns when passed a negative value [perl #83048].
199
200=item *
201
202C<srand()> now warns when passed a value that doesn't fit in a C<UV> (since the
203value will be truncated rather than overflowing) [perl #40605].
7d101ed1 204
e96e0834 205=back
d9661073 206
e96e0834 207=head2 Changes to Existing Diagnostics
95c6c5c5 208
e96e0834 209XXX Changes (i.e. rewording) of diagnostic messages go here
95c6c5c5 210
e96e0834 211=over 4
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212
213=item *
214
e96e0834 215XXX Describe change here
3630f57e 216
e96e0834 217=back
3630f57e 218
e96e0834 219=head1 Utility Changes
95c6c5c5 220
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221XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
222here. Most of these are built within the directories F<utils> and F<x2p>.
95c6c5c5 223
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224[ List utility changes as a =head3 entry for each utility and =item
225entries for each change
226Use L<XXX> with program names to get proper documentation linking. ]
95c6c5c5 227
e96e0834 228=head3 L<XXX>
95c6c5c5 229
e96e0834 230=over 4
95c6c5c5
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231
232=item *
233
e96e0834 234XXX
95c6c5c5 235
e96e0834 236=back
95c6c5c5 237
e96e0834 238=head1 Configuration and Compilation
95c6c5c5 239
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240XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
241go here. Any other changes to the Perl build process should be listed here.
242However, any platform-specific changes should be listed in the
243L</Platform Support> section, instead.
95c6c5c5 244
e96e0834 245[ List changes as a =item entry ].
95c6c5c5 246
e96e0834 247=over 4
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248
249=item *
250
e96e0834 251XXX
95c6c5c5 252
e96e0834 253=back
95c6c5c5 254
e96e0834 255=head1 Testing
95c6c5c5 256
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257XXX Any significant changes to the testing of a freshly built perl should be
258listed here. Changes which create B<new> files in F<t/> go here as do any
259large changes to the testing harness (e.g. when parallel testing was added).
260Changes to existing files in F<t/> aren't worth summarising, although the bugs
261that they represent may be covered elsewhere.
95c6c5c5 262
e96e0834 263[ List each test improvement as a =item entry ]
95c6c5c5 264
e96e0834 265=over 4
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266
267=item *
268
e96e0834 269XXX
95c6c5c5 270
61174fb5 271=back
f558db2f 272
e96e0834 273=head1 Platform Support
05c8f9ed 274
e96e0834 275XXX Any changes to platform support should be listed in the sections below.
05c8f9ed 276
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277[ Within the sections, list each platform as a =item entry with specific
278changes as paragraphs below it. ]
9dea6244 279
e96e0834 280=head2 New Platforms
9dea6244 281
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282XXX List any platforms that this version of perl compiles on, that previous
283versions did not. These will either be enabled by new files in the F<hints/>
284directories, or new subdirectories and F<README> files at the top level of the
285source tree.
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286
287=over 4
288
e96e0834 289=item XXX-some-platform
7d101ed1 290
e96e0834 291XXX
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292
293=back
294
e96e0834 295=head2 Discontinued Platforms
ef7131e9 296
e96e0834 297XXX List any platforms that this version of perl no longer compiles on.
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298
299=over 4
300
e96e0834 301=item XXX-some-platform
8dffc0ab 302
e96e0834 303XXX
dbc84d79 304
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305=back
306
61174fb5 307=head2 Platform-Specific Notes
ceb0881c 308
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309XXX List any changes for specific platforms. This could include configuration
310and compilation changes or changes in portability/compatibility. However,
311changes within modules for platforms should generally be listed in the
312L</Modules and Pragmata> section.
89cbc6b8 313
e96e0834 314=over 4
0998713f 315
e96e0834 316=item XXX-some-platform
112b6866 317
e96e0834 318XXX
112b6866 319
61174fb5 320=back
8e125188 321
61174fb5 322=head1 Internal Changes
8e125188 323
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324XXX Changes which affect the interface available to C<XS> code go here.
325Other significant internal changes for future core maintainers should
326be noted as well.
c4643160 327
e96e0834 328[ List each change as a =item entry ]
f8ef51fd 329
e96e0834 330=over 4
e128ab2c 331
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332=item *
333
e96e0834 334XXX
e2f0c3bb 335
61174fb5 336=back
422287bf 337
61174fb5 338=head1 Selected Bug Fixes
2de6ba8d 339
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340XXX Important bug fixes in the core language are summarised here.
341Bug fixes in files in F<ext/> and F<lib/> are best summarised in
342L</Modules and Pragmata>.
52c4b146 343
e96e0834 344[ List each fix as a =item entry ]
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345
346=over 4
347
348=item *
349
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350A regression introduced in v5.14.0 has been fixed, in which some calls
351to the C<re> module would clobber C<$_>.
e128ab2c 352
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353=item *
354
355C<do FILE> now always either sets or clears C<$@>, even when the file can't be
356read. This ensures that testing C<$@> first (as recommended by the
357documentation) always returns the correct result.
358
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359=item *
360
361The array iterator used for the C<each @array> construct is now correctly
362reset when C<@array> is cleared (RT #75596). This happens for example when the
363array is globally assigned to, as in C<@array = (...)>, but not when its
364B<values> are assigned to. In terms of the XS API, it means that C<av_clear()>
365will now reset the iterator.
366
367This mirrors the behaviour of the hash iterator when the hash is cleared.
368
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369=item *
370
371C<< $class->can >>, C<< $class->isa >>, and C<< $class->DOES >> now return
372correct results, regardless of whether that package referred to by C<$class>
373exists [perl #47113].
374
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375=item *
376
377Arriving signals no longer clear C<$@> [perl #45173].
378
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379=item *
380
381Allow C<my ()> declarations with an empty variable list [perl #113554].
382
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383=item *
384
385During parsing, subs declared after errors no longer leave stubs
386[perl #113712].
387
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388=item *
389
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390Closures containing no string evals no longer hang on to their containing
391subroutines, allowing variables closed over by outer subroutines to be
392freed when the outer sub is freed, even if the inner sub still exists
393[perl #89544].
394
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395=item *
396
397Duplication of in-memory filehandles by opening with a "<&=" or ">&=" mode
398stopped working properly in 5.16.0. It was causing the new handle to
399reference a different scalar variable. This has been fixed [perl #113764].
400
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401=back
402
e96e0834 403=head1 Known Problems
dbc84d79 404
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405XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
406tests that had to be C<TODO>ed for the release would be noted here. Unfixed
407platform specific bugs also go here.
53de3ff0 408
e96e0834 409[ List each fix as a =item entry ]
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410
411=over 4
412
413=item *
414
e96e0834 415XXX
233bba44 416
e96e0834 417=back
233bba44 418
e96e0834 419=head1 Obituary
233bba44 420
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421XXX If any significant core contributor has died, we've added a short obituary
422here.
233bba44 423
61174fb5 424=head1 Acknowledgements
d5dc7001 425
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426XXX Generate this with:
427
428 perl Porting/acknowledgements.pl v5.17.1..HEAD
29cf780c 429
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430=head1 Reporting Bugs
431
432If you find what you think is a bug, you might check the articles
52deee2e 433recently posted to the comp.lang.perl.misc newsgroup and the perl
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434bug database at http://rt.perl.org/perlbug/ . There may also be
435information at http://www.perl.org/ , the Perl Home Page.
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436
437If you believe you have an unreported bug, please run the L<perlbug>
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438program included with your release. Be sure to trim your bug down
439to a tiny but sufficient test case. Your bug report, along with the
440output of C<perl -V>, will be sent off to perlbug@perl.org to be
441analysed by the Perl porting team.
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442
443If the bug you are reporting has security implications, which make it
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444inappropriate to send to a publicly archived mailing list, then please send
445it to perl5-security-report@perl.org. This points to a closed subscription
446unarchived mailing list, which includes
447all the core committers, who will be able
448to help assess the impact of issues, figure out a resolution, and help
449co-ordinate the release of patches to mitigate or fix the problem across all
450platforms on which Perl is supported. Please only use this address for
451security issues in the Perl core, not for modules independently
452distributed on CPAN.
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453
454=head1 SEE ALSO
455
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456The F<Changes> file for an explanation of how to view exhaustive details
457on what changed.
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458
459The F<INSTALL> file for how to build Perl.
460
461The F<README> file for general stuff.
462
463The F<Artistic> and F<Copying> files for copyright information.
464
465=cut