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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
e96e0834 111=back
c506fc7e 112
e96e0834 113=head2 Removed Modules and Pragmata
c506fc7e 114
e96e0834 115=over 4
95c6c5c5 116
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117=item *
118
e96e0834 119XXX
95c6c5c5 120
e96e0834 121=back
95c6c5c5 122
e96e0834 123=head1 Documentation
95c6c5c5 124
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125XXX Changes to files in F<pod/> go here. Consider grouping entries by
126file and be sure to link to the appropriate page, e.g. L<perlfunc>.
95c6c5c5 127
e96e0834 128=head2 New Documentation
1c633914 129
e96e0834 130XXX Changes which create B<new> files in F<pod/> go here.
f558db2f 131
e96e0834 132=head3 L<XXX>
66aa79e2 133
e96e0834 134XXX Description of the purpose of the new file here
95c6c5c5 135
e96e0834 136=head2 Changes to Existing Documentation
95c6c5c5 137
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138XXX Changes which significantly change existing files in F<pod/> go here.
139However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
140section.
95c6c5c5 141
e96e0834 142=head3 L<XXX>
95c6c5c5 143
e96e0834 144=over 4
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145
146=item *
147
e96e0834 148XXX Description of the change here
95c6c5c5 149
e96e0834 150=back
95c6c5c5 151
e96e0834 152=head1 Diagnostics
95c6c5c5 153
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154The following additions or changes have been made to diagnostic output,
155including warnings and fatal error messages. For the complete list of
156diagnostic messages, see L<perldiag>.
95c6c5c5 157
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158XXX New or changed warnings emitted by the core's C<C> code go here. Also
159include any changes in L<perldiag> that reconcile it to the C<C> code.
71014848 160
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161[ Within each section, list entries as a =item entry that links to perldiag,
162 e.g.
71014848 163
e96e0834 164 =item *
95c6c5c5 165
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166 L<Invalid version object|perldiag/"Invalid version object">
167]
95c6c5c5 168
e96e0834 169=head2 New Diagnostics
95c6c5c5 170
e96e0834 171XXX Newly added diagnostic messages go here
95c6c5c5 172
e96e0834 173=head3 New Errors
95c6c5c5 174
e96e0834 175=over 4
95c6c5c5 176
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177=item *
178
e96e0834 179XXX L<message|perldiag/"message">
95c6c5c5 180
e96e0834 181=back
95c6c5c5 182
e96e0834 183=head3 New Warnings
95c6c5c5 184
e96e0834 185=over 4
95c6c5c5 186
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187=item *
188
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189C<chr()> now warns when passed a negative value [perl #83048].
190
191=item *
192
193C<srand()> now warns when passed a value that doesn't fit in a C<UV> (since the
194value will be truncated rather than overflowing) [perl #40605].
7d101ed1 195
e96e0834 196=back
d9661073 197
e96e0834 198=head2 Changes to Existing Diagnostics
95c6c5c5 199
e96e0834 200XXX Changes (i.e. rewording) of diagnostic messages go here
95c6c5c5 201
e96e0834 202=over 4
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203
204=item *
205
e96e0834 206XXX Describe change here
3630f57e 207
e96e0834 208=back
3630f57e 209
e96e0834 210=head1 Utility Changes
95c6c5c5 211
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212XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
213here. Most of these are built within the directories F<utils> and F<x2p>.
95c6c5c5 214
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215[ List utility changes as a =head3 entry for each utility and =item
216entries for each change
217Use L<XXX> with program names to get proper documentation linking. ]
95c6c5c5 218
e96e0834 219=head3 L<XXX>
95c6c5c5 220
e96e0834 221=over 4
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222
223=item *
224
e96e0834 225XXX
95c6c5c5 226
e96e0834 227=back
95c6c5c5 228
e96e0834 229=head1 Configuration and Compilation
95c6c5c5 230
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231XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
232go here. Any other changes to the Perl build process should be listed here.
233However, any platform-specific changes should be listed in the
234L</Platform Support> section, instead.
95c6c5c5 235
e96e0834 236[ List changes as a =item entry ].
95c6c5c5 237
e96e0834 238=over 4
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239
240=item *
241
e96e0834 242XXX
95c6c5c5 243
e96e0834 244=back
95c6c5c5 245
e96e0834 246=head1 Testing
95c6c5c5 247
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248XXX Any significant changes to the testing of a freshly built perl should be
249listed here. Changes which create B<new> files in F<t/> go here as do any
250large changes to the testing harness (e.g. when parallel testing was added).
251Changes to existing files in F<t/> aren't worth summarising, although the bugs
252that they represent may be covered elsewhere.
95c6c5c5 253
e96e0834 254[ List each test improvement as a =item entry ]
95c6c5c5 255
e96e0834 256=over 4
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257
258=item *
259
e96e0834 260XXX
95c6c5c5 261
61174fb5 262=back
f558db2f 263
e96e0834 264=head1 Platform Support
05c8f9ed 265
e96e0834 266XXX Any changes to platform support should be listed in the sections below.
05c8f9ed 267
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268[ Within the sections, list each platform as a =item entry with specific
269changes as paragraphs below it. ]
9dea6244 270
e96e0834 271=head2 New Platforms
9dea6244 272
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273XXX List any platforms that this version of perl compiles on, that previous
274versions did not. These will either be enabled by new files in the F<hints/>
275directories, or new subdirectories and F<README> files at the top level of the
276source tree.
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277
278=over 4
279
e96e0834 280=item XXX-some-platform
7d101ed1 281
e96e0834 282XXX
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283
284=back
285
e96e0834 286=head2 Discontinued Platforms
ef7131e9 287
e96e0834 288XXX List any platforms that this version of perl no longer compiles on.
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289
290=over 4
291
e96e0834 292=item XXX-some-platform
8dffc0ab 293
e96e0834 294XXX
dbc84d79 295
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296=back
297
61174fb5 298=head2 Platform-Specific Notes
ceb0881c 299
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300XXX List any changes for specific platforms. This could include configuration
301and compilation changes or changes in portability/compatibility. However,
302changes within modules for platforms should generally be listed in the
303L</Modules and Pragmata> section.
89cbc6b8 304
e96e0834 305=over 4
0998713f 306
e96e0834 307=item XXX-some-platform
112b6866 308
e96e0834 309XXX
112b6866 310
61174fb5 311=back
8e125188 312
61174fb5 313=head1 Internal Changes
8e125188 314
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315XXX Changes which affect the interface available to C<XS> code go here.
316Other significant internal changes for future core maintainers should
317be noted as well.
c4643160 318
e96e0834 319[ List each change as a =item entry ]
f8ef51fd 320
e96e0834 321=over 4
e128ab2c 322
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323=item *
324
e96e0834 325XXX
e2f0c3bb 326
61174fb5 327=back
422287bf 328
61174fb5 329=head1 Selected Bug Fixes
2de6ba8d 330
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331XXX Important bug fixes in the core language are summarised here.
332Bug fixes in files in F<ext/> and F<lib/> are best summarised in
333L</Modules and Pragmata>.
52c4b146 334
e96e0834 335[ List each fix as a =item entry ]
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336
337=over 4
338
339=item *
340
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341A regression introduced in v5.14.0 has been fixed, in which some calls
342to the C<re> module would clobber C<$_>.
e128ab2c 343
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344=item *
345
346C<do FILE> now always either sets or clears C<$@>, even when the file can't be
347read. This ensures that testing C<$@> first (as recommended by the
348documentation) always returns the correct result.
349
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350=item *
351
352The array iterator used for the C<each @array> construct is now correctly
353reset when C<@array> is cleared (RT #75596). This happens for example when the
354array is globally assigned to, as in C<@array = (...)>, but not when its
355B<values> are assigned to. In terms of the XS API, it means that C<av_clear()>
356will now reset the iterator.
357
358This mirrors the behaviour of the hash iterator when the hash is cleared.
359
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360=item *
361
362C<< $class->can >>, C<< $class->isa >>, and C<< $class->DOES >> now return
363correct results, regardless of whether that package referred to by C<$class>
364exists [perl #47113].
365
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366=item *
367
368Arriving signals no longer clear C<$@> [perl #45173].
369
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370=back
371
e96e0834 372=head1 Known Problems
dbc84d79 373
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374XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
375tests that had to be C<TODO>ed for the release would be noted here. Unfixed
376platform specific bugs also go here.
53de3ff0 377
e96e0834 378[ List each fix as a =item entry ]
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379
380=over 4
381
382=item *
383
e96e0834 384XXX
233bba44 385
e96e0834 386=back
233bba44 387
e96e0834 388=head1 Obituary
233bba44 389
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390XXX If any significant core contributor has died, we've added a short obituary
391here.
233bba44 392
61174fb5 393=head1 Acknowledgements
d5dc7001 394
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395XXX Generate this with:
396
397 perl Porting/acknowledgements.pl v5.17.1..HEAD
29cf780c 398
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399=head1 Reporting Bugs
400
401If you find what you think is a bug, you might check the articles
52deee2e 402recently posted to the comp.lang.perl.misc newsgroup and the perl
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403bug database at http://rt.perl.org/perlbug/ . There may also be
404information at http://www.perl.org/ , the Perl Home Page.
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405
406If you believe you have an unreported bug, please run the L<perlbug>
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407program included with your release. Be sure to trim your bug down
408to a tiny but sufficient test case. Your bug report, along with the
409output of C<perl -V>, will be sent off to perlbug@perl.org to be
410analysed by the Perl porting team.
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411
412If the bug you are reporting has security implications, which make it
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413inappropriate to send to a publicly archived mailing list, then please send
414it to perl5-security-report@perl.org. This points to a closed subscription
415unarchived mailing list, which includes
416all the core committers, who will be able
417to help assess the impact of issues, figure out a resolution, and help
418co-ordinate the release of patches to mitigate or fix the problem across all
419platforms on which Perl is supported. Please only use this address for
420security issues in the Perl core, not for modules independently
421distributed on CPAN.
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422
423=head1 SEE ALSO
424
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425The F<Changes> file for an explanation of how to view exhaustive details
426on what changed.
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427
428The F<INSTALL> file for how to build Perl.
429
430The F<README> file for general stuff.
431
432The F<Artistic> and F<Copying> files for copyright information.
433
434=cut