This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
rt74170: test case that triggered the problem
[perl5.git] / pod / perldelta.pod
CommitLineData
4c793fe3
FR
1=encoding utf8
2
8ebb9810 3=for release_engineer
b3364d98 4* changelogged up to be34c38
8ebb9810
FR
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
4c793fe3
FR
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
0c692eed
FR
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.)
4c793fe3
FR
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
d6747b7a 66=head2 C API changes
4c793fe3 67
d6747b7a
NC
68The first argument of the C API function C<Perl_fetch_cop_label> has changed
69from C<struct refcounted he *> to C<COP *>, to better insulate the user from
70implementation details.
4c793fe3 71
d6747b7a
NC
72This API function was marked as "may change", and likely isn't in use outside
73the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other
74references to it.)
4c793fe3
FR
75
76=head1 Deprecations
77
78XXX Any deprecated features, syntax, modules etc. should be listed here.
79In particular, deprecated modules should be listed here even if they are
80listed as an updated module in the L</Modules and Pragmata> section.
81
82[ List each deprecation as a =head2 entry ]
83
84=head1 Performance Enhancements
85
86XXX Changes which enhance performance without changing behaviour go here. There
87may well be none in a stable release.
88
89[ List each enhancement as a =item entry ]
90
91=over 4
92
93=item *
94
0c692eed
FR
95Scalars containing regular expressions now only allocate the part of the C<SV>
96body they actually use, saving some space.
4c793fe3
FR
97
98=back
99
100=head1 Modules and Pragmata
101
102XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
103go here. If Module::CoreList is updated, generate an initial draft of the
104following sections using F<Porting/corelist-perldelta.pl>, which prints stub
105entries to STDOUT. Results can be pasted in place of the '=head2' entries
106below. A paragraph summary for important changes should then be added by hand.
107In an ideal world, dual-life modules would have a F<Changes> file that could be
108cribbed.
109
110[ Within each section, list entries as a =item entry ]
111
112=head2 New Modules and Pragmata
113
114=over 4
115
116=item *
117
118XXX
119
120=back
121
122=head2 Updated Modules and Pragmata
123
124=over 4
125
126=item *
127
8ebb9810
FR
128C<blib> has been upgraded from version 1.05 to 1.06.
129
130=item *
131
b3364d98
FR
132C<bignum>, C<bigint>, and C<bigrat> have been upgraded from version 0.23 to
1330.24.
134
135=item *
136
48c1efd2
FR
137C<Errno> has been upgraded from version 1.12 to 1.13.
138
139On some platforms with unusual header files, like Win32/gcc using mingw64
140headers, some constants which weren't actually error numbers have been exposed
141by C<Errno>. This has been fixed (RT#77416).
142
143=item *
144
0c692eed
FR
145C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_01.
146
147=item *
148
b3364d98
FR
149C<Filter::Simple> has been upgraded from version 0.84 to 0.85.
150
151=item *
152
48c1efd2
FR
153C<Math::BigInt> has been upgraded from version 1.89_01 to 1.90.
154C<Math::BigInt::Calc> has been upgraded from version 0.52 to 0.53.
155
156This fixes incorrect results when computing binomial coefficients (RT#77640).
157
158=item *
159
b3364d98
FR
160C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.21.
161
162=item *
163
c9a84c8b
NC
164C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
165
48c1efd2 166Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
c9a84c8b
NC
167
168=item *
169
0c692eed 170C<Unicode::Collate> has been upgraded from version 0.56 to 0.58.
4c793fe3 171
48c1efd2
FR
172=item *
173
174C<XSLoader> has been upgraded from version 0.10 to 0.11.
175
4c793fe3
FR
176=back
177
178=head2 Removed Modules and Pragmata
179
180=over 4
181
182=item *
183
184XXX
185
186=back
187
188=head1 Documentation
189
190XXX Changes to files in F<pod/> go here. Consider grouping entries by
191file and be sure to link to the appropriate page, e.g. L<perlfunc>.
192
193=head2 New Documentation
194
195XXX Changes which create B<new> files in F<pod/> go here.
196
197=head3 L<XXX>
198
199XXX Description of the purpose of the new file here
200
201=head2 Changes to Existing Documentation
202
203XXX Changes which significantly change existing files in F<pod/> go here.
204However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
205section.
206
0c692eed 207=head3 L<perlapi>
4c793fe3
FR
208
209=over 4
210
211=item *
212
0c692eed 213Many of the optree construction functions are now documented.
4c793fe3
FR
214
215=back
216
217=head1 Diagnostics
218
219The following additions or changes have been made to diagnostic output,
220including warnings and fatal error messages. For the complete list of
221diagnostic messages, see L<perldiag>.
222
223XXX New or changed warnings emitted by the core's C<C> code go here. Also
224include any changes in L<perldiag> that reconcile it to the C<C> code.
225
226[ Within each section, list entries as a =item entry ]
227
228=head2 New Diagnostics
229
230XXX Newly added diagnostic messages go here
231
232=over 4
233
234=item *
235
236XXX
237
238=back
239
240=head2 Changes to Existing Diagnostics
241
242XXX Changes (i.e. rewording) of diagnostic messages go here
243
244=over 4
245
246=item *
247
248XXX
249
250=back
251
252=head1 Utility Changes
253
254XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
255here. Most of these are built within the directories F<utils> and F<x2p>.
256
257[ List utility changes as a =head3 entry for each utility and =item
258entries for each change
259Use L<XXX> with program names to get proper documentation linking. ]
260
48c1efd2 261=head3 L<h2ph>
4c793fe3
FR
262
263=over 4
264
265=item *
266
48c1efd2 267The use of a deprecated C<goto> construct has been removed (RT#74404).
4c793fe3
FR
268
269=back
270
271=head1 Configuration and Compilation
272
273XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
274go here. Any other changes to the Perl build process should be listed here.
275However, any platform-specific changes should be listed in the
276L</Platform Support> section, instead.
277
278[ List changes as a =item entry ].
279
280=over 4
281
282=item *
283
284XXX
285
286=back
287
288=head1 Testing
289
290XXX Any significant changes to the testing of a freshly built perl should be
291listed here. Changes which create B<new> files in F<t/> go here as do any
292large changes to the testing harness (e.g. when parallel testing was added).
293Changes to existing files in F<t/> aren't worth summarising, although the bugs
294that they represent may be covered elsewhere.
295
296[ List each test improvement as a =item entry ]
297
298=over 4
299
300=item *
301
0c692eed
FR
302A rare race condition in F<t/op/while_readdir.t> has been fixed, stopping it
303from failing randomly when running tests in parallel.
4c793fe3
FR
304
305=back
306
307=head1 Platform Support
308
309XXX Any changes to platform support should be listed in the sections below.
310
311[ Within the sections, list each platform as a =item entry with specific
312changes as paragraphs below it. ]
313
314=head2 New Platforms
315
316XXX List any platforms that this version of perl compiles on, that previous
317versions did not. These will either be enabled by new files in the F<hints/>
318directories, or new subdirectories and F<README> files at the top level of the
319source tree.
320
321=over 4
322
323=item XXX-some-platform
324
325XXX
326
327=back
328
329=head2 Discontinued Platforms
330
331XXX List any platforms that this version of perl no longer compiles on.
332
333=over 4
334
335=item XXX-some-platform
336
337XXX
338
339=back
340
341=head2 Platform-Specific Notes
342
343XXX List any changes for specific platforms. This could include configuration
344and compilation changes or changes in portability/compatibility. However,
345changes within modules for platforms should generally be listed in the
346L</Modules and Pragmata> section.
347
348=over 4
349
0c692eed 350=item VMS
4c793fe3 351
0c692eed
FR
352=over 4
353
354=item *
355
356Make PerlIOUnix_open honor default permissions on VMS.
357
358When perlio became the default and unixio became the default bottom layer, the
359most common path for creating files from Perl became C<PerlIOUnix_open>, which
360has always explicitly used C<0666> as the permission mask.
361
362To avoid this, C<0777> is now passed as the permissions to C<open()>. In the VMS
363CRTL, C<0777> has a special meaning over and above intersecting with the current
364umask; specifically, it allows Unix syscalls to preserve native default
365permissions.
366
367=back
4c793fe3
FR
368
369=back
370
371=head1 Internal Changes
372
373XXX Changes which affect the interface available to C<XS> code go here.
374Other significant internal changes for future core maintainers should
375be noted as well.
376
377[ List each test improvement as a =item entry ]
378
379=over 4
380
381=item *
382
0c692eed
FR
383C<CALL_FPTR> and C<CPERLscope> have been removed deprecated.
384
385Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
386which has been removed in 5.8. Nowadays these macros do exactly nothing, so they
387shouldn't be used anymore.
388
389For compatibility, they are still defined for external C<XS> code. Only
390extensions defining C<PERL_CORE> must be updated now.
391
392=item *
393
394C<lex_stuff_pvs()> has been added as a convenience macro wrapping
395C<lex_stuff_pvn()> for literal strings.
396
397=item *
398
399The recursive part of the peephole optimizer is how hookable.
400
401In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
402C<PL_rpeepp> is now available to hook into the optimizer recursing into
403side-chains of the optree.
4c793fe3
FR
404
405=back
406
407=head1 Selected Bug Fixes
408
409XXX Important bug fixes in the core language are summarised here.
410Bug fixes in files in F<ext/> and F<lib/> are best summarised in
411L</Modules and Pragmata>.
412
413[ List each fix as a =item entry ]
414
415=over 4
416
417=item *
418
0c692eed
FR
419A regression introduced in perl 5.10.0, making
420C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
421fixed. C<$x> will now be C<undef>.
422
423=item *
424
425A fatal error in regular expressions when processing UTF-8 data has been fixed
426(RT#75680).
427
428=item *
429
430An erroneous regular expression engine optimization, that caused regex verbs
431like C<*COMMIT> to sometimes be ignored, has been removed.
432
433=item *
434
435The perl debugger now also works in taint mode (RT#76872).
4c793fe3 436
8ebb9810
FR
437=item *
438
439Several memory leaks in cloning and freeing threaded perl interpreters have been
440fixed (RT#77352).
441
48c1efd2
FR
442=item *
443
444A possible string corruption when doing regular expression matches on overloaded
445objects has been fixed (RT#77084).
446
4c793fe3
FR
447=back
448
449=head1 Known Problems
450
451XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
452tests that had to be C<TODO>ed for the release would be noted here, unless
453they were specific to a particular platform (see below).
454
455This is a list of some significant unfixed bugs, which are regressions
456from either 5.XXX.XXX or 5.XXX.XXX.
457
458[ List each fix as a =item entry ]
459
460=over 4
461
462=item *
463
464XXX
465
466=back
467
468=head1 Obituary
469
470XXX If any significant core contributor has died, we've added a short obituary
471here.
472
473=head1 Acknowledgements
474
475XXX The list of people to thank goes here.
476
477=head1 Reporting Bugs
478
479If you find what you think is a bug, you might check the articles
480recently posted to the comp.lang.perl.misc newsgroup and the perl
481bug database at http://rt.perl.org/perlbug/ . There may also be
482information at http://www.perl.org/ , the Perl Home Page.
483
484If you believe you have an unreported bug, please run the B<perlbug>
485program included with your release. Be sure to trim your bug down
486to a tiny but sufficient test case. Your bug report, along with the
487output of C<perl -V>, will be sent off to perlbug@perl.org to be
488analysed by the Perl porting team.
489
490If the bug you are reporting has security implications, which make it
491inappropriate to send to a publicly archived mailing list, then please send
492it to perl5-security-report@perl.org. This points to a closed subscription
493unarchived mailing list, which includes all the core committers, who be able
494to help assess the impact of issues, figure out a resolution, and help
495co-ordinate the release of patches to mitigate or fix the problem across all
496platforms on which Perl is supported. Please only use this address for
497security issues in the Perl core, not for modules independently
498distributed on CPAN.
499
500=head1 SEE ALSO
501
502The F<Changes> file for an explanation of how to view exhaustive details
503on what changed.
504
505The F<INSTALL> file for how to build Perl.
506
507The F<README> file for general stuff.
508
509The F<Artistic> and F<Copying> files for copyright information.
510
511=cut