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1=encoding utf8
2
8ebb9810 3=for release_engineer
ccb45ef4 4* changelogged up to f4beb78
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5* the mauve module will not be part of the release, so it's not changelogged
6yet. it also added some new api functions. those aren't covered either, as they
7might go away again in case mauve gets rolled back for 5.13.5.
8
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9=head1 NAME
10
11[ this is a template for a new perldelta file. Any text flagged as
12XXX needs to be processed before release. ]
13
14perldelta - what is new for perl v5.13.5
15
16=head1 DESCRIPTION
17
18This document describes differences between the 5.13.4 release and
19the 5.13.5 release.
20
21If you are upgrading from an earlier release such as 5.13.3, first read
22L<perl5134delta>, which describes differences between 5.13.3 and
235.13.4.
24
25=head1 Notice
26
27XXX Any important notices here
28
29=head1 Core Enhancements
30
31XXX New core language features go here. Summarise user-visible core language
32enhancements. Particularly prominent performance optimisations could go
33here, but most should go in the L</Performance Enhancements> section.
34
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35=head2 Adjacent pairs of nextstate opcodes are now optimized away
36
37Previously, in code such as
38
39 use constant DEBUG => 0;
40
41 sub GAK {
42 warn if DEBUG;
43 print "stuff\n";
44 }
45
46the ops for C<warn if DEBUG;> would be folded to a C<null> op (C<ex-const>), but
47the C<nextstate> op would remain, resulting in a runtime op dispatch of
48C<nextstate>, C<nextstate>, ...
49
50The execution of a sequence of C<nexstate> ops is indistinguishable from just
51the last C<nextstate> op, so teach the peephole optimiser to eliminate the first
52of a pair of C<nextstate> ops. (Except where the first carries a label, as
53labels mustn't be eliminated by the optimiser, and label usage isn't
54conclusively known at compile time.)
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55
56=head1 Security
57
58XXX Any security-related notices go here. In particular, any security
59vulnerabilities closed should be noted here rather than in the
60L</Selected Bug Fixes> section.
61
62[ List each security issue as a =head2 entry ]
63
64=head1 Incompatible Changes
65
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66=head2 Magic Variables Outside the Main Package
67
68In previous versions of perl, magic variables like C<$!>, C<%SIG>, etc. would
69'leak' into other packages. So C<%foo::SIG> could be used to access signals,
70C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
71
72This was a bug, or an 'unintentional' feature, which caused various ill
73effects, such as signal handlers being wiped when modules were loaded, etc.
74
75This has been fixed (or the feature has been removed, depending on how you
76see it).
77
d6747b7a 78=head2 C API changes
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80The first argument of the C API function C<Perl_fetch_cop_label> has changed
81from C<struct refcounted he *> to C<COP *>, to better insulate the user from
82implementation details.
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84This API function was marked as "may change", and likely isn't in use outside
85the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other
86references to it.)
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87
88=head1 Deprecations
89
90XXX Any deprecated features, syntax, modules etc. should be listed here.
91In particular, deprecated modules should be listed here even if they are
92listed as an updated module in the L</Modules and Pragmata> section.
93
94[ List each deprecation as a =head2 entry ]
95
96=head1 Performance Enhancements
97
98XXX Changes which enhance performance without changing behaviour go here. There
99may well be none in a stable release.
100
101[ List each enhancement as a =item entry ]
102
103=over 4
104
105=item *
106
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107Scalars containing regular expressions now only allocate the part of the C<SV>
108body they actually use, saving some space.
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109
110=back
111
112=head1 Modules and Pragmata
113
114XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
115go here. If Module::CoreList is updated, generate an initial draft of the
116following sections using F<Porting/corelist-perldelta.pl>, which prints stub
117entries to STDOUT. Results can be pasted in place of the '=head2' entries
118below. A paragraph summary for important changes should then be added by hand.
119In an ideal world, dual-life modules would have a F<Changes> file that could be
120cribbed.
121
122[ Within each section, list entries as a =item entry ]
123
124=head2 New Modules and Pragmata
125
126=over 4
127
128=item *
129
130XXX
131
132=back
133
134=head2 Updated Modules and Pragmata
135
136=over 4
137
138=item *
139
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140C<blib> has been upgraded from version 1.05 to 1.06.
141
142=item *
143
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144C<bignum>, C<bigint>, and C<bigrat> have been upgraded from version 0.23 to
1450.24.
146
147=item *
148
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149C<Data::Dumper> has been upgraded from version 2.126 to XXX.
150
151This fixes a crash when using custom sort functions that might cause the stack
152to change.
153
154=item *
155
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156C<Errno> has been upgraded from version 1.12 to 1.13.
157
158On some platforms with unusual header files, like Win32/gcc using mingw64
159headers, some constants which weren't actually error numbers have been exposed
160by C<Errno>. This has been fixed (RT#77416).
161
162=item *
163
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164C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_01.
165
166=item *
167
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168C<Filter::Simple> has been upgraded from version 0.84 to 0.85.
169
170=item *
171
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172C<Math::BigInt> has been upgraded from version 1.89_01 to 1.90.
173C<Math::BigInt::Calc> has been upgraded from version 0.52 to 0.53.
174
175This fixes incorrect results when computing binomial coefficients (RT#77640).
176
177=item *
178
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179C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.21.
180
181=item *
182
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183C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
184
48c1efd2 185Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
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186
187=item *
188
ccb45ef4 189C<Unicode::Collate> has been upgraded from version 0.56 to 0.59.
4c793fe3 190
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191=item *
192
193C<XSLoader> has been upgraded from version 0.10 to 0.11.
194
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195=back
196
197=head2 Removed Modules and Pragmata
198
199=over 4
200
201=item *
202
203XXX
204
205=back
206
207=head1 Documentation
208
209XXX Changes to files in F<pod/> go here. Consider grouping entries by
210file and be sure to link to the appropriate page, e.g. L<perlfunc>.
211
212=head2 New Documentation
213
214XXX Changes which create B<new> files in F<pod/> go here.
215
216=head3 L<XXX>
217
218XXX Description of the purpose of the new file here
219
220=head2 Changes to Existing Documentation
221
222XXX Changes which significantly change existing files in F<pod/> go here.
223However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
224section.
225
0c692eed 226=head3 L<perlapi>
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227
228=over 4
229
230=item *
231
0c692eed 232Many of the optree construction functions are now documented.
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233
234=back
235
236=head1 Diagnostics
237
238The following additions or changes have been made to diagnostic output,
239including warnings and fatal error messages. For the complete list of
240diagnostic messages, see L<perldiag>.
241
242XXX New or changed warnings emitted by the core's C<C> code go here. Also
243include any changes in L<perldiag> that reconcile it to the C<C> code.
244
245[ Within each section, list entries as a =item entry ]
246
247=head2 New Diagnostics
248
249XXX Newly added diagnostic messages go here
250
251=over 4
252
253=item *
254
255XXX
256
257=back
258
259=head2 Changes to Existing Diagnostics
260
261XXX Changes (i.e. rewording) of diagnostic messages go here
262
263=over 4
264
265=item *
266
267XXX
268
269=back
270
271=head1 Utility Changes
272
273XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
274here. Most of these are built within the directories F<utils> and F<x2p>.
275
276[ List utility changes as a =head3 entry for each utility and =item
277entries for each change
278Use L<XXX> with program names to get proper documentation linking. ]
279
48c1efd2 280=head3 L<h2ph>
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281
282=over 4
283
284=item *
285
48c1efd2 286The use of a deprecated C<goto> construct has been removed (RT#74404).
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287
288=back
289
290=head1 Configuration and Compilation
291
292XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
293go here. Any other changes to the Perl build process should be listed here.
294However, any platform-specific changes should be listed in the
295L</Platform Support> section, instead.
296
297[ List changes as a =item entry ].
298
299=over 4
300
301=item *
302
303XXX
304
305=back
306
307=head1 Testing
308
309XXX Any significant changes to the testing of a freshly built perl should be
310listed here. Changes which create B<new> files in F<t/> go here as do any
311large changes to the testing harness (e.g. when parallel testing was added).
312Changes to existing files in F<t/> aren't worth summarising, although the bugs
313that they represent may be covered elsewhere.
314
315[ List each test improvement as a =item entry ]
316
317=over 4
318
319=item *
320
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321A rare race condition in F<t/op/while_readdir.t> has been fixed, stopping it
322from failing randomly when running tests in parallel.
4c793fe3 323
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324=item *
325
326The new F<t/op/leaky-magic.t> script tests that magic applied to variables in
327the main packages does not affect other packages.
328
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329=back
330
331=head1 Platform Support
332
333XXX Any changes to platform support should be listed in the sections below.
334
335[ Within the sections, list each platform as a =item entry with specific
336changes as paragraphs below it. ]
337
338=head2 New Platforms
339
340XXX List any platforms that this version of perl compiles on, that previous
341versions did not. These will either be enabled by new files in the F<hints/>
342directories, or new subdirectories and F<README> files at the top level of the
343source tree.
344
345=over 4
346
347=item XXX-some-platform
348
349XXX
350
351=back
352
353=head2 Discontinued Platforms
354
355XXX List any platforms that this version of perl no longer compiles on.
356
357=over 4
358
359=item XXX-some-platform
360
361XXX
362
363=back
364
365=head2 Platform-Specific Notes
366
367XXX List any changes for specific platforms. This could include configuration
368and compilation changes or changes in portability/compatibility. However,
369changes within modules for platforms should generally be listed in the
370L</Modules and Pragmata> section.
371
372=over 4
373
0c692eed 374=item VMS
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376=over 4
377
378=item *
379
380Make PerlIOUnix_open honor default permissions on VMS.
381
382When perlio became the default and unixio became the default bottom layer, the
383most common path for creating files from Perl became C<PerlIOUnix_open>, which
384has always explicitly used C<0666> as the permission mask.
385
386To avoid this, C<0777> is now passed as the permissions to C<open()>. In the VMS
387CRTL, C<0777> has a special meaning over and above intersecting with the current
388umask; specifically, it allows Unix syscalls to preserve native default
389permissions.
390
391=back
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392
393=back
394
395=head1 Internal Changes
396
397XXX Changes which affect the interface available to C<XS> code go here.
398Other significant internal changes for future core maintainers should
399be noted as well.
400
401[ List each test improvement as a =item entry ]
402
403=over 4
404
405=item *
406
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407C<CALL_FPTR> and C<CPERLscope> have been removed deprecated.
408
409Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
410which has been removed in 5.8. Nowadays these macros do exactly nothing, so they
411shouldn't be used anymore.
412
413For compatibility, they are still defined for external C<XS> code. Only
414extensions defining C<PERL_CORE> must be updated now.
415
416=item *
417
418C<lex_stuff_pvs()> has been added as a convenience macro wrapping
419C<lex_stuff_pvn()> for literal strings.
420
421=item *
422
423The recursive part of the peephole optimizer is how hookable.
424
425In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
426C<PL_rpeepp> is now available to hook into the optimizer recursing into
427side-chains of the optree.
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428
429=back
430
431=head1 Selected Bug Fixes
432
433XXX Important bug fixes in the core language are summarised here.
434Bug fixes in files in F<ext/> and F<lib/> are best summarised in
435L</Modules and Pragmata>.
436
437[ List each fix as a =item entry ]
438
439=over 4
440
441=item *
442
f4beb78f 443A regression introduced in perl 5.12.0, making
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444C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
445fixed. C<$x> will now be C<undef>.
446
447=item *
448
449A fatal error in regular expressions when processing UTF-8 data has been fixed
450(RT#75680).
451
452=item *
453
454An erroneous regular expression engine optimization, that caused regex verbs
455like C<*COMMIT> to sometimes be ignored, has been removed.
456
457=item *
458
459The perl debugger now also works in taint mode (RT#76872).
4c793fe3 460
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461=item *
462
463Several memory leaks in cloning and freeing threaded perl interpreters have been
464fixed (RT#77352).
465
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466=item *
467
468A possible string corruption when doing regular expression matches on overloaded
469objects has been fixed (RT#77084).
470
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471=item *
472
473Magic applied to variables in the main package no longer affects other
474packages. See L</Magic Variables Outside the Main Package>, above [perl #76138].
475
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476=item *
477
478Opening a glob reference via C<< open $fh, ">", \*glob >> will no longer cause
479the glob to be corrupted when the file handle is printed to. This would cause
480perl to crash whenever the glob's contents were accessed [perl #77492].
481
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482=item *
483
d827d4bf 484The postincrement and postdecrement operators, C<++> and C<--> used to cause
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485leaks when being used on references. This has now been fixed.
486
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487=back
488
489=head1 Known Problems
490
491XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
492tests that had to be C<TODO>ed for the release would be noted here, unless
493they were specific to a particular platform (see below).
494
495This is a list of some significant unfixed bugs, which are regressions
496from either 5.XXX.XXX or 5.XXX.XXX.
497
498[ List each fix as a =item entry ]
499
500=over 4
501
502=item *
503
504XXX
505
506=back
507
508=head1 Obituary
509
510XXX If any significant core contributor has died, we've added a short obituary
511here.
512
513=head1 Acknowledgements
514
515XXX The list of people to thank goes here.
516
517=head1 Reporting Bugs
518
519If you find what you think is a bug, you might check the articles
520recently posted to the comp.lang.perl.misc newsgroup and the perl
521bug database at http://rt.perl.org/perlbug/ . There may also be
522information at http://www.perl.org/ , the Perl Home Page.
523
524If you believe you have an unreported bug, please run the B<perlbug>
525program included with your release. Be sure to trim your bug down
526to a tiny but sufficient test case. Your bug report, along with the
527output of C<perl -V>, will be sent off to perlbug@perl.org to be
528analysed by the Perl porting team.
529
530If the bug you are reporting has security implications, which make it
531inappropriate to send to a publicly archived mailing list, then please send
532it to perl5-security-report@perl.org. This points to a closed subscription
533unarchived mailing list, which includes all the core committers, who be able
534to help assess the impact of issues, figure out a resolution, and help
535co-ordinate the release of patches to mitigate or fix the problem across all
536platforms on which Perl is supported. Please only use this address for
537security issues in the Perl core, not for modules independently
538distributed on CPAN.
539
540=head1 SEE ALSO
541
542The F<Changes> file for an explanation of how to view exhaustive details
543on what changed.
544
545The F<INSTALL> file for how to build Perl.
546
547The F<README> file for general stuff.
548
549The F<Artistic> and F<Copying> files for copyright information.
550
551=cut