This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Remove support for ?PATTERN? without explicit 'm' operator
[perl5.git] / pod / perldelta.pod
CommitLineData
44691e6f
AB
1=encoding utf8
2
3=head1 NAME
4
7065301c
RS
5[ this is a template for a new perldelta file. Any text flagged as XXX needs
6to be processed before release. ]
7
8perldelta - what is new for perl v5.21.1
c68523cb 9
238894db 10=head1 DESCRIPTION
c68523cb 11
7065301c 12This document describes differences between the 5.21.0 release and the 5.21.1
238894db 13release.
c68523cb 14
7065301c
RS
15If you are upgrading from an earlier release such as 5.20.0, first read
16L<perl5210delta>, which describes differences between 5.20.0 and 5.21.0.
17
18=head1 Notice
19
20XXX Any important notices here
21
22=head1 Core Enhancements
23
24XXX New core language features go here. Summarize user-visible core language
25enhancements. Particularly prominent performance optimisations could go
26here, but most should go in the L</Performance Enhancements> section.
27
28[ List each enhancement as a =head2 entry ]
29
09edd811
KW
30=head2 Unicode 7.0 is now supported
31
32For details on what is in this release, see
33L<http://www.unicode.org/versions/Unicode7.0.0/>.
34
7e957246
MH
35=head2 Experimental C Backtrace API
36
37Starting from Perl 5.21.1, on some platforms Perl supports retrieving
38the C level backtrace (similar to what symbolic debuggers like gdb do).
39
40The backtrace returns the stack trace of the C call frames,
41with the symbol names (function names), the object names (like "perl"),
42and if it can, also the source code locations (file:line).
43
44The supported platforms are Linux and OS X (some *BSD might work at
45least partly, but they have not yet been tested).
46
47The feature needs to be enabled with C<Configure -Dusecbacktrace>.
48
49Also included is a C API to retrieve backtraces.
50
51See L<perlhacktips/"C backtrace"> for more information.
52
8373491a
KW
53=head2 C<qr/foo/x> now ignores any Unicode pattern white space
54
55The C</x> regular expression modifier allows the pattern to contain
56white space and comments, both of which are ignored, for improved
57readability. Until now, not all the white space characters that Unicode
58designates for this purpose were handled. The additional ones now
59recognized are
60U+0085 NEXT LINE,
61U+200E LEFT-TO-RIGHT MARK,
62U+200F RIGHT-TO-LEFT MARK,
63U+2028 LINE SEPARATOR,
64and
65U+2029 PARAGRAPH SEPARATOR.
66
d6ded950
KW
67=head2 S<C<use locale>> can restrict which locale categories are affected
68
69It is now possible to pass a parameter to S<C<use locale>> to specify
70a subset of locale categories to be locale-aware, with the remaining
71ones unaffected. See L<perllocale/The "use locale" pragma> for details.
72
7065301c
RS
73=head1 Security
74
75XXX Any security-related notices go here. In particular, any security
76vulnerabilities closed should be noted here rather than in the
77L</Selected Bug Fixes> section.
78
79[ List each security issue as a =head2 entry ]
80
81=head1 Incompatible Changes
82
83XXX For a release on a stable branch, this section aspires to be:
84
85 There are no changes intentionally incompatible with 5.XXX.XXX
86 If any exist, they are bugs, and we request that you submit a
87 report. See L</Reporting Bugs> below.
88
b06e47f7
KW
89=head2 S<C<"use encoding">> now is a fatal error
90
91The C<encoding> pragma has been deprecated since v5.18, and its use now
92is a fatal error.
93
98b7895c
MH
94=head2 C<\N{}> with a sequence of multiple spaces is now a fatal error.
95
96This has been deprecated since v5.18.
97
7357bd17
KW
98=head2 In double-quotish C<\cI<X>>, I<X> must now be a printable ASCII character
99
100In prior releases, failure to do this raised a deprecation warning.
7065301c 101
cd209d9d
KW
102=head2 Splitting the tokens C<(?> and C<(*> in regular expressions is
103now a fatal compilation error.
104
105These had been deprecated since v5.18.
106
8373491a
KW
107=head2 5 additional characters are treated as white space under C</x> in
108regex patterns (unless escaped)
109
110The use of these characters with C</x> outside bracketed character
111classes and when not preceeded by a backslash has raised a deprecation
112warning since v5.18. Now they will be ignored. See L</qrE<sol>fooE<sol>x>
113for the list of the five characters.
114
115=head2 Comment lines within S<C<(?[ ])>> now are ended only by a C<\n>
116
117S<C<(?[ ])>> is an experimental feature, introduced in v5.18. It operates
118as if C</x> is always enabled. But there was a difference, comment
119lines (following a C<#> character) were terminated by anything matching
120C<\R> which includes all vertical whitespace, such as form feeds. For
121consistency, this is now changed to match what terminates comment lines
122outside S<C<(?[ ])>>, namely a C<\n> (even if escaped), which is the
123same as what terminates a heredoc string and formats.
124
b5adc3e5
DIM
125=head2 Omitting % and @ on hash and array names is no longer permitted
126
127Really old Perl let you omit the @ on array names and the % on hash
128names in some spots. This has issued a deprecation warning since Perl
1295.0, and is no longer permitted.
130
2c6ee1a7
KW
131=head2 C<"$!"> text is now in English outside C<"use locale"> scope
132
133Previously, the text, unlike almost everything else, always came out
134based on the current underlying locale of the program. (Also affected
135on some systems is C<"$^E>".) For programs that are unprepared to
136handle locale, this can cause garbage text to be displayed. It's better
137to display text that is translatable via some tool than garbage text
138which is much harder to figure out.
139
5320b60d
KW
140=head2 C<"$!"> text will be returned in UTF-8 when appropriate
141
142The stringification of C<$!> and C<$^E> will have the UTF-8 flag set
143when the text is actually non-ASCII UTF-8. This will enable programs
144that are set up to be locale-aware to properly output messages in the
145user's native language. Code that needs to continue the 5.20 and
146earlier behavior can do the stringification within the scopes of both
147'use bytes' and 'use locale ":messages". No other Perl operations will
148be affected by locale; only C<$!> and C<$^E> stringification. The
149'bytes' pragma causes the UTF-8 flag to not be set, just as in previous
150Perl releases. This resolves [perl #112208].
151
6f9b3131
JH
152=head2 MAD build option has been removed
153
154MAD = Misc Attribute Decoration; unmaintained attempt at preserving
155the Perl parse tree more faithfully so that automatic conversion of
156Perl 5 to Perl 6 would have been easier.
157
158This build-time configuration option had been unmaintained for years,
159and had probably seriously diverged on both Perl 5 and Perl 6 sides.
160
c3383756
DIM
161=head2 Support for C<?PATTERN?> without explicit operator has been removed
162
163Starting regular expressions matching only once directly with the
164question mark delimiter is now a syntax error, so that the question mark
165can be available for use in new operators. Write C<m?PATTERN?> instead,
166explicitly using the C<m> operator: the question mark delimiter still
167invokes match-once behaviour.
168
7065301c
RS
169=head1 Deprecations
170
171XXX Any deprecated features, syntax, modules etc. should be listed here.
172
df758df2
KW
173=head2 Using a NO-BREAK space in a character alias for C<\N{...}> is now
174deprecated
175
176This non-graphic character is essentially indistinguishable from a
177regular space, and so should not be allowed. See
178L<charnames/CUSTOM ALIASES>.
179
412f55bb
KW
180=head2 A literal C<"{"> should now be escaped in a pattern
181
182If you want a literal left curly bracket (also called a left brace) in a
183regular expression pattern, you should now escape it by either
184preceding it with a backslash (C<"\{">) or enclosing it within square
185brackets C<"[{]">, or by using C<\Q>; otherwise a deprecation warning
186will be raised. This was first announced as forthcoming in the v5.16
187release; it will allow future extensions to the language to happen.
188
7065301c
RS
189=head2 Module removals
190
191XXX Remove this section if inapplicable.
192
193The following modules will be removed from the core distribution in a
194future release, and will at that time need to be installed from CPAN.
195Distributions on CPAN which require these modules will need to list them as
196prerequisites.
197
198The core versions of these modules will now issue C<"deprecated">-category
199warnings to alert you to this fact. To silence these deprecation warnings,
200install the modules in question from CPAN.
201
202Note that these are (with rare exceptions) fine modules that you are encouraged
203to continue to use. Their disinclusion from core primarily hinges on their
204necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
205not usually on concerns over their design.
206
207=over
208
209=item XXX
210
211XXX Note that deprecated modules should be listed here even if they are listed
212as an updated module in the L</Modules and Pragmata> section.
213
214=back
215
216[ List each other deprecation as a =head2 entry ]
217
218=head1 Performance Enhancements
219
220XXX Changes which enhance performance without changing behaviour go here.
221There may well be none in a stable release.
222
223[ List each enhancement as a =item entry ]
224
225=over 4
226
227=item *
228
8a16341a
MH
229Many internal functions have been refactored to improve performance and reduce
230their memory footprints.
d133a3dd
MH
231
232L<[perl #121436]|https://rt.perl.org/Ticket/Display.html?id=121436>
8a16341a
MH
233L<[perl #121906]|https://rt.perl.org/Ticket/Display.html?id=121906>
234L<[perl #121969]|https://rt.perl.org/Ticket/Display.html?id=121969>
7065301c 235
6bb82be0
MH
236=item *
237
238C<-T> and C<-B> filetests will return sooner when an empty file is detected.
239
240L<perl #121489|https://rt.perl.org/Ticket/Display.html?id=121489>
241
7065301c
RS
242=back
243
7ef8b31d 244=head1 Modules and Pragmata
f6f3144e 245
7065301c
RS
246XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
247go here. If Module::CoreList is updated, generate an initial draft of the
248following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
249for important changes should then be added by hand. In an ideal world,
250dual-life modules would have a F<Changes> file that could be cribbed.
251
252[ Within each section, list entries as a =item entry ]
253
254=head2 New Modules and Pragmata
24a38d90
RS
255
256=over 4
257
258=item *
259
7065301c
RS
260XXX
261
262=back
263
264=head2 Updated Modules and Pragmata
265
266=over 4
24a38d90
RS
267
268=item *
269
56cdf413
TC
270L<Carp> has been upgraded from version 1.3301 to 1.34.
271
272Carp::Heavy now ignores version mismatches with Carp if Carp is newer
273than 1.12, since Carp::Heavy's guts were merged into Carp at that
274point.
275L<[perl #121574]|https://rt.perl.org/Ticket/Display.html?id=121574>
276
277=item *
278
f9dc9a54
TC
279L<Data::Dumper> has been upgraded from version 2.151 to 2.152.
280
281Changes to resolve Coverity issues.
282
283XS dumps incorrectly stored the name of code references stored in a
284GLOB.
285L<[perl #122070]|https://rt.perl.org/Ticket/Display.html?id=122070>
286
287=item *
288
28e02325
SH
289L<Encode> has been upgraded from version 2.60_01 to 2.62.
290
291B<piconv> now has better error handling when the encoding name is nonexistent,
292and a build breakage when upgrading L<Encode> in perl-5.8.2 and earlier has
293been fixed.
294
295=item *
296
cb526893
TC
297L<Hash::Util> has been upgraded from version 0.16 to 0.17.
298
299Minor bug fixes and documentation fixes to Hash::Util::hash_stats()
300
301=item *
302
5abafd4c
SH
303The libnet collection of modules has been upgraded from version 1.25 to 1.27.
304
305There are only whitespace changes to the installed files.
306
307=item *
308
7a945bf5
SH
309The Locale-Codes collection of modules has been upgraded from vesion 3.30 to 3.31.
310
311Fixed a bug in the scripts used to extract data from spreadsheets that
312prevented the SHP currency code from being found.
313L<[cpan #94229]|https://rt.cpan.org/Ticket/Display.html?id=94229>
314
315=item *
316
4ed8f5ed
TC
317L<Math::BigInt> has been upgraded from version 1.9993 to 1.9994.
318
319Synchronize POD changes from the CPAN release.
320
ee15bb65
TC
321C<< Math::BigFloat->blog(x) >> would sometimes return blog(2*x) when
322the accuracy was greater than 70 digits.
323
324The result of C<< Math::BigFloat->bdiv() >> in list context now
325satisfies C<< x = quotient * divisor + remainder >>.
326
4ed8f5ed
TC
327=item *
328
234105dd
TC
329L<Math::BigRat> has been upgraded from version 0.2606 to 0.2607.
330
331Synchronize POD changes from the CPAN release.
332
333=item *
334
f97d984b 335L<Module::Metadata> has been upgraded from version 1.000022 to 1.000024.
b9beed70
SH
336
337Support installations on older perls with an L<ExtUtils::MakeMaker> earlier
338than 6.63_03
339
340=item *
341
f9dc9a54
TC
342L<OS2::Process> has been upgraded from version 1.09 to 1.10.
343
344=item *
345
c13fd1a2
TC
346L<perl5db.pl> has been upgraded from version 1.44 to 1.45.
347
348fork() in the debugger under C<tmux> will now create a new window for
891822fa
TC
349the forked process. L<[perl
350#121333]|https://rt.perl.org/Ticket/Display.html?id=121333>
351
352The debugger now saves the current working directory on startup and
353restores it when you restart your program with C<R> or <rerun>. L<[perl
354#121509]|https://rt.perl.org/Ticket/Display.html?id=121509>
24a38d90 355
cb526893
TC
356=item *
357
f9dc9a54
TC
358L<PerlIO::encoding> has been upgraded from version 0.18 to 0.19.
359
360No changes in behaviour.
361
362=item *
363
364L<PerlIO::mmap> has been upgraded from version 0.012 to 0.013.
365
366No changes in behaviour.
367
368=item *
369
370L<PerlIO::scalar> has been upgraded from version 0.18 to 0.19.
371
372No changes in behaviour.
373
374=item *
375
f8187d97
SH
376L<Unicode::Collate> has been upgraded from version 1.04 to 1.07.
377
378Version 0.67's improved discontiguous contractions is invalidated by default
379and is supported as a parameter 'long_contraction'.
380
95f3e8d2
SH
381=item *
382
383L<Unicode::Normalize> has been upgraded from version 1.17 to 1.18.
384
385The XSUB implementation has been removed in favour of pure Perl.
386
3eaa3d14
YO
387=item *
388
cb526893
TC
389A mismatch between the documentation and the code in utf8::downgrade()
390was fixed in favour of the documentation. The optional second argument
391is now correctly treated as a perl boolean (true/false semantics) and
392not as an integer.
3eaa3d14 393
238894db 394=back
24a38d90 395
92fa985e 396=head2 Removed Modules and Pragmata
24a38d90 397
238894db 398=over 4
24a38d90
RS
399
400=item *
401
7065301c
RS
402XXX
403
404=back
405
406=head1 Documentation
407
408XXX Changes to files in F<pod/> go here. Consider grouping entries by
409file and be sure to link to the appropriate page, e.g. L<perlfunc>.
410
411=head2 New Documentation
412
413XXX Changes which create B<new> files in F<pod/> go here.
414
415=head3 L<XXX>
416
417XXX Description of the purpose of the new file here
418
419=head2 Changes to Existing Documentation
420
421XXX Changes which significantly change existing files in F<pod/> go here.
422However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
423section.
424
9c0f2733 425=head3 L<perlfunc>
7065301c
RS
426
427=over 4
428
429=item *
430
9c0f2733
MH
431C<-l> now notes that it will return false if symlinks aren't supported by the
432file system.
433
434L<[perl #121523]|https://rt.perl.org/Ticket/Display.html?id=121523>
7065301c 435
902c1f75
MH
436=item *
437
438Note that C<exec LIST> and C<system LIST> may fall back to the shell on
439Win32. Only C<exec PROGRAM LIST> and C<system PROGRAM LIST> indirect object
440syntax will reliably avoid using the shell.
441
442This has also been noted in L<perlport>.
443
444L<[perl #122046]|https://rt.perl.org/Ticket/Display.html?id=122046>
445
7065301c
RS
446=back
447
58f25ac1
MH
448=head3 L<perlapi>
449
450=over 4
451
452=item *
453
454C<sv_usepvn_flags> - Fix documentation to mention the use of C<NewX> instead of
455C<malloc>.
456
457L<[perl #121869]|https://rt.perl.org/Ticket/Display.html?id=121869>
458
4c6609d3
MH
459=item *
460
461Clarify where C<NUL> may be embedded or is required to terminate a string.
462
5bafdaa4
MH
463=item *
464
465Previously missing documentation due to formatting errors are now included.
466
467=item *
468
469Entries are now organized into groups rather than by file where they are found.
470
471=item *
472
473Alphabetical sorting of entries is now handled by the POD generator to make
474entries easier to find when scanning.
475
58f25ac1
MH
476=back
477
12042f24
MH
478=head3 L<perlhacktips>
479
480=over 4
481
482=item *
483
484Updated documentation for the C<test.valgrind> C<make> target.
485
486L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
487
488=back
489
2705070b
MH
490=head3 L<perlre>
491
492=over 4
493
494=item *
495
496The C</x> modifier has been clarified to note that comments cannot be continued
497onto the next line by escaping them.
498
499=back
500
b10906fb
MH
501=head3 L<Unicode::UCD>
502
503=over 4
504
505=item *
506
507The documentation includes many clarifications and fixes.
508
509=back
510
7065301c
RS
511=head1 Diagnostics
512
513The following additions or changes have been made to diagnostic output,
514including warnings and fatal error messages. For the complete list of
515diagnostic messages, see L<perldiag>.
516
517XXX New or changed warnings emitted by the core's C<C> code go here. Also
518include any changes in L<perldiag> that reconcile it to the C<C> code.
519
520=head2 New Diagnostics
521
522XXX Newly added diagnostic messages go under here, separated into New Errors
523and New Warnings
524
525=head3 New Errors
526
527=over 4
24a38d90
RS
528
529=item *
530
7065301c
RS
531XXX L<message|perldiag/"message">
532
533=back
534
535=head3 New Warnings
536
537=over 4
24a38d90
RS
538
539=item *
540
097675bf
TC
541L<PerlIO layer ':win32' is experimental|perldiag/"PerlIO layer ':win32' is experimental">:
542
543(S experimental::win32_perlio) The C<:win32> PerlIO layer is
544experimental. If you want to take the risk of using this layer,
545simply disable this warning:
546
547 no warnings "experimental::win32_perlio";
24a38d90 548
238894db 549=back
24a38d90 550
7065301c 551=head2 Changes to Existing Diagnostics
24a38d90 552
7065301c 553XXX Changes (i.e. rewording) of diagnostic messages go here
24a38d90 554
7065301c
RS
555=over 4
556
557=item *
558
747b6130
MH
559<> should be quotes
560
561This warning has been changed to
562L<< <> at require-statement should be quotes|perldiag/"<> at require-statement should be quotes" >>
563to make the issue more identifiable.
564
565=item *
566
723edb96
TC
567L<Unsuccessful %s on filename containing newline|perldiag/"Unsuccessful %s on filename containing newline">
568
569This warning is now only produced when the newline is at the end of
570the filename.
7065301c
RS
571
572=back
573
574=head1 Utility Changes
575
576XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
eb561242 577Most of these are built within the directory F<utils>.
7065301c
RS
578
579[ List utility changes as a =head2 entry for each utility and =item
580entries for each change
581Use L<XXX> with program names to get proper documentation linking. ]
582
eb561242 583=head2 F<x2p/>
7065301c
RS
584
585=over 4
586
587=item *
24a38d90 588
eb561242
MH
589The F<x2p/> directory has been removed from the Perl core.
590
591This removes find2perl, s2p and a2p. They have all been released to CPAN as
592separate distributions (App::find2perl, App::s2p, App::a2p).
7065301c
RS
593
594=back
595
596=head1 Configuration and Compilation
597
598XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
599go here. Any other changes to the Perl build process should be listed here.
600However, any platform-specific changes should be listed in the
601L</Platform Support> section, instead.
602
603[ List changes as a =item entry ].
604
605=over 4
606
607=item *
608
12042f24
MH
609C<make test.valgrind> now supports parallel testing.
610
611For example:
612
613 TEST_JOBS=9 make test.valgrind
614
615See L<perlhacktips/valgrind> for more information.
616
617L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
7065301c
RS
618
619=back
620
621=head1 Testing
622
623XXX Any significant changes to the testing of a freshly built perl should be
624listed here. Changes which create B<new> files in F<t/> go here as do any
625large changes to the testing harness (e.g. when parallel testing was added).
626Changes to existing files in F<t/> aren't worth summarizing, although the bugs
627that they represent may be covered elsewhere.
628
629[ List each test improvement as a =item entry ]
630
631=over 4
632
633=item *
634
635XXX
636
637=back
638
639=head1 Platform Support
640
641XXX Any changes to platform support should be listed in the sections below.
642
643[ Within the sections, list each platform as a =item entry with specific
644changes as paragraphs below it. ]
645
646=head2 New Platforms
647
648XXX List any platforms that this version of perl compiles on, that previous
649versions did not. These will either be enabled by new files in the F<hints/>
650directories, or new subdirectories and F<README> files at the top level of the
651source tree.
652
653=over 4
654
655=item XXX-some-platform
656
657XXX
658
659=back
660
661=head2 Discontinued Platforms
662
663XXX List any platforms that this version of perl no longer compiles on.
664
665=over 4
666
f05550c0 667=item NeXTSTEP/OPENSTEP
7065301c 668
f05550c0
BF
669NeXTSTEP was proprietary OS bundled with NeXT's workstations in the early
670to mid 90's; OPENSTEP was an API specification that provided a NeXTSTEP-like
671environment on a non-NeXTSTEP system. Both are now long dead, so support
672for building Perl on them has been removed.
7065301c
RS
673
674=back
675
676=head2 Platform-Specific Notes
677
678XXX List any changes for specific platforms. This could include configuration
679and compilation changes or changes in portability/compatibility. However,
680changes within modules for platforms should generally be listed in the
681L</Modules and Pragmata> section.
682
683=over 4
684
685=item XXX-some-platform
686
687XXX
688
7d0ccdba
MH
689=item OpenBSD
690
691On OpenBSD, Perl will now default to using the system C<malloc> due to the
692security features it provides. Perl's own malloc wrapper has been in use
693since v5.14 due to performance reasons, but the OpenBSD project believes
694the tradeoff is worth it and would prefer that users who need the speed
695specifically ask for it.
696
697L<[perl #122000]|https://rt.perl.org/Ticket/Display.html?id=122000>.
698
7065301c
RS
699=back
700
701=head1 Internal Changes
702
703XXX Changes which affect the interface available to C<XS> code go here. Other
704significant internal changes for future core maintainers should be noted as
705well.
706
7065301c
RS
707=over 4
708
709=item *
710
8dab3ba5 711The deprecated variable C<PL_sv_objcount> has been removed.
7065301c 712
4c28b29c
KW
713=item *
714
715Perl now tries to keep the locale category C<LC_NUMERIC> set to "C"
716except around operations that need it to be set to the program's
717underlying locale. This protects the many XS modules that cannot cope
718with the decimal radix character not being a dot. Prior to this
719release, Perl initialized this category to "C", but a call to
720C<POSIX::setlocale()> would change it. Now such a call will change the
721underlying locale of the C<LC_NUMERIC> category for the program, but the
722locale exposed to XS code will remain "C". There is an API under
723development for those relatively few modules that need to use the
724underlying locale. This API will be nailed down during the course of
725developing v5.21. Send email to L<mailto:perl5-porters@perl.org> for
726guidance.
727
c9fcb674
KW
728=item *
729
730A new macro L<C<isUTF8_CHAR>|perlapi/isUTF8_CHAR> has been written which
731efficiently determines if the string given by its parameters begins
732with a well-formed UTF-8 encoded character.
733
7065301c
RS
734=back
735
736=head1 Selected Bug Fixes
737
738XXX Important bug fixes in the core language are summarized here. Bug fixes in
739files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
740
741[ List each fix as a =item entry ]
742
743=over 4
744
745=item *
746
30536d4a
TC
747index() and rindex() no longer crash when used on strings over 2GB in
748size.
749L<[perl #121562]|https://rt.perl.org/Ticket/Display.html?id=121562>.
7065301c 750
0c2c57a8
DD
751=item *
752
753A small previously intentional memory leak in PERL_SYS_INIT/PERL_SYS_INIT3 on
754Win32 builds was fixed. This might affect embedders who repeatedly create and
755destroy perl engines within the same process.
756
a835cd47
KW
757=item *
758
759C<POSIX::localeconv()> now returns the data for the program's underlying
760locale even when called from outside the scope of S<C<use locale>>.
761
03ceeedf
KW
762=item *
763
764C<POSIX::localeconv()> now works properly on platforms which don't have
765C<LC_NUMERIC> and/or C<LC_MONETARY>, or for which Perl has been compiled
766to disregard either or both of these locale categories. In such
767circumstances, there are now no entries for the corresponding values in
768the hash returned by C<localeconv()>.
769
c1284011
KW
770=item *
771
772C<POSIX::localeconv()> now marks appropriately the values it returns as
773UTF-8 or not. Previously they were always returned as a bytes, even if
774they were supposed to be encoded as UTF-8.
775
375f5f06
KW
776=item *
777
778On Microsoft Windows, within the scope of C<S<use locale>>, the following
779POSIX character classes gave results for many locales that did not
780conform to the POSIX standard:
781C<[[:alnum:]]>,
782C<[[:alpha:]]>,
783C<[[:blank:]]>,
784C<[[:digit:]]>,
785C<[[:graph:]]>,
786C<[[:lower:]]>,
787C<[[:print:]]>,
788C<[[:punct:]]>,
789C<[[:upper:]]>,
790C<[[:word:]]>,
791and
792C<[[:xdigit:]]>.
793These are because the underlying Microsoft implementation does not
794follow the standard. Perl now takes special precautions to correct for
795this.
796
2884baee
MH
797=item *
798
799Many issues have been detected by L<Coverity|http://www.coverity.com/> and
800fixed.
801
5af51eb4
BF
802=item *
803
804system() and friends should now work properly on more Android builds.
805
806Due to an oversight, the value specified through -Dtargetsh to Configure
807would end up being ignored by some of the build process. This caused perls
808cross-compiled for Android to end up with defective versions of system(),
809exec() and backticks: the commands would end up looking for C</bin/sh>
810instead of C</system/bin/sh>, and so would fail for the vast majority
811of devices, leaving C<$!> as C<ENOENT>.
812
412f55bb
KW
813=item *
814
815C<qr(...\(...\)...)>,
816C<qr[...\[...\]...]>,
817and
818C<qr{...\{...\}...}>
819now work. Previously it was impossible to escape these three
820left-characters with a backslash within a regular expression pattern
821where otherwise they would be considered metacharacters, and the pattern
822opening delimiter was the character, and the closing delimiter was its
823mirror character.
824
7065301c
RS
825=back
826
827=head1 Known Problems
828
829XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
830tests that had to be C<TODO>ed for the release would be noted here. Unfixed
831platform specific bugs also go here.
832
833[ List each fix as a =item entry ]
834
835=over 4
836
837=item *
838
839XXX
840
841=back
842
843=head1 Errata From Previous Releases
844
845=over 4
846
847=item *
848
849XXX Add anything here that we forgot to add, or were mistaken about, in
850the perldelta of a previous release.
851
852=back
853
854=head1 Obituary
855
856XXX If any significant core contributor has died, we've added a short obituary
857here.
858
859=head1 Acknowledgements
24a38d90 860
7065301c 861XXX Generate this with:
52e02e68 862
7065301c 863 perl Porting/acknowledgements.pl v5.21.1..HEAD
f5b73711 864
44691e6f
AB
865=head1 Reporting Bugs
866
e08634c5
SH
867If you find what you think is a bug, you might check the articles recently
868posted to the comp.lang.perl.misc newsgroup and the perl bug database at
238894db 869https://rt.perl.org/ . There may also be information at
7ef8b31d 870http://www.perl.org/ , the Perl Home Page.
44691e6f 871
e08634c5
SH
872If you believe you have an unreported bug, please run the L<perlbug> program
873included with your release. Be sure to trim your bug down to a tiny but
874sufficient test case. Your bug report, along with the output of C<perl -V>,
875will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
44691e6f
AB
876
877If the bug you are reporting has security implications, which make it
e08634c5
SH
878inappropriate to send to a publicly archived mailing list, then please send it
879to perl5-security-report@perl.org. This points to a closed subscription
880unarchived mailing list, which includes all the core committers, who will be
881able to help assess the impact of issues, figure out a resolution, and help
f9001595 882co-ordinate the release of patches to mitigate or fix the problem across all
e08634c5
SH
883platforms on which Perl is supported. Please only use this address for
884security issues in the Perl core, not for modules independently distributed on
885CPAN.
44691e6f
AB
886
887=head1 SEE ALSO
888
e08634c5
SH
889The F<Changes> file for an explanation of how to view exhaustive details on
890what changed.
44691e6f
AB
891
892The F<INSTALL> file for how to build Perl.
893
894The F<README> file for general stuff.
895
896The F<Artistic> and F<Copying> files for copyright information.
897
898=cut