4 This has been completed up to 62e907591, except for:
5 803e389 rurban CYG17 utf8 paths
6 d9298c1 rurban mymalloc isn't thread safe
10 [ this is a template for a new perldelta file. Any text flagged as
11 XXX needs to be processed before release. ]
13 perldelta - what is new for perl v5.15.8
17 This document describes differences between the 5.15.7 release and
20 If you are upgrading from an earlier release such as 5.15.6, first read
21 L<perl5157delta>, which describes differences between 5.15.6 and
26 XXX Any important notices here
28 =head1 Core Enhancements
30 XXX New core language features go here. Summarise user-visible core language
31 enhancements. Particularly prominent performance optimisations could go
32 here, but most should go in the L</Performance Enhancements> section.
34 [ List each enhancement as a =head2 entry ]
36 =head2 Improved ability to mix locales and Unicode, including UTF-8 locales
38 An optional parameter has been added to C<use locale>
40 use locale ':not_characters';
42 which tells Perl to use all but the C<LC_CTYPE> and C<LC_COLLATE>
43 portions of the current locale. Instead, the character set is assumed
44 to be Unicode. This allows locales and Unicode to be seamlessly mixed,
45 including the increasingly frequent UTF-8 locales. When using this
46 hybrid form of locales, the C<:locale> layer to the L<open> pragma can
47 be used to interface with the file system, and there are CPAN modules
48 available for ARGV and environment variable conversions.
50 Full details are in L<perllocale>.
52 =head2 New function C<fc> and corresponding escape sequence C<\F> for Unicode foldcase
54 Unicode foldcase is an extension to lowercase that gives better results
55 when comparing two strings case-insensitively. It has long been used
56 internally in regular expression C</i> matching. Now it is available
57 explicitly through the new C<fc> function call (enabled by
58 S<C<"use feature 'fc'">>, or C<use v5.16>, or explicitly callable via
59 C<CORE::fc>) or through the new C<\F> sequence in double-quotish
62 Full details are in L<perlfunc/fc>.
64 =head2 C<_> in subroutine prototypes
66 The C<_> character in subroutine prototypes is now allowed before C<@> or
71 XXX Any security-related notices go here. In particular, any security
72 vulnerabilities closed should be noted here rather than in the
73 L</Selected Bug Fixes> section.
75 [ List each security issue as a =head2 entry ]
77 =head1 Incompatible Changes
79 XXX For a release on a stable branch, this section aspires to be:
81 There are no changes intentionally incompatible with 5.XXX.XXX
82 If any exist, they are bugs, and we request that you submit a
83 report. See L</Reporting Bugs> below.
85 [ List each incompatible change as a =head2 entry ]
87 =head2 Special blocks called in void context
89 Special blocks (C<BEGIN>, C<CHECK>, C<INIT>, C<UNITCHECK>, C<END>) are now
90 called in void context. This avoids wasteful copying of the result of the
91 last statement [perl #108794].
93 =head2 The C<overloading> pragma and regexp objects
95 With C<no overloading>, regular expression objects returned by C<qr//> are
96 now stringified as "Regexp=REGEXP(0xbe600d)" instead of the regular
97 expression itself [perl #108780].
99 =head2 Two XS typemap Entries removed
101 Two presumably unused XS typemap entries have been removed from the
102 core typemap: T_DATAUNIT and T_CALLBACK. If you are, against all odds,
103 a user of these, please see the instructions on how to regain them
108 XXX Any deprecated features, syntax, modules etc. should be listed here.
109 In particular, deprecated modules should be listed here even if they are
110 listed as an updated module in the L</Modules and Pragmata> section.
112 [ List each deprecation as a =head2 entry ]
114 =head1 Performance Enhancements
116 XXX Changes which enhance performance without changing behaviour go here. There
117 may well be none in a stable release.
119 [ List each enhancement as a =item entry ]
129 =head1 Modules and Pragmata
131 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
132 go here. If Module::CoreList is updated, generate an initial draft of the
133 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
134 entries to STDOUT. Results can be pasted in place of the '=head2' entries
135 below. A paragraph summary for important changes should then be added by hand.
136 In an ideal world, dual-life modules would have a F<Changes> file that could be
139 [ Within each section, list entries as a =item entry ]
141 =head2 New Modules and Pragmata
147 The C<mmap> PerlIO layer is no longer implemented by perl itself, but has
148 been moved out into the new L<PerlIO::mmap> module.
152 =head2 Updated Modules and Pragmata
158 L<arybase> has been upgraded from version 0.03 to version 0.04.
160 List slices no longer modify items on the stack belonging to outer lists
165 L<B> has been upgraded from version 1.33 to version 1.34.
167 C<B::COP> now has a C<stashflags> method, corresponding to a new internal
168 field added in 5.15.4 [perl #108860].
172 L<Compress::Raw::Bzip2> has been upgraded from version 2.045 to version 2.048.
176 L<Compress::Raw::Zlib> has been upgraded from version 2.045 to version 2.048.
180 L<Compress::Zlib> has been upgraded from version 2.046 to version 2.048.
184 L<DB_File> has been upgraded from version 1.824 to version 1.826.
188 L<diagnostics> has been upgraded from version 1.27 to version 1.28.
190 When searching for F<perldiag.pod>, it no longer uses paths that were only
191 relevant on Perl 5.004 and earlier.
195 L<ExtUtils::ParseXS> has been upgraded from version 3.12 to version 3.15.
197 The new version comes with important tools for sharing typemaps between
198 different CPAN distributions.
202 L<File::Copy> has been upgraded from version 2.21 to version 2.23.
204 It no longer emits warnings when copying files with newlines in their names
209 L<IPC::Cmd> has been upgraded from version 0.72 to version 0.76.
213 L<Math::Complex> has been upgraded from version 1.58 to version 1.59.
215 This avoids a new core warning.
219 L<Pod::Parser> has been upgraded from version 1.37 to version 1.51.
223 L<Term::ReadLine> has been upgraded from version 1.07 to version 1.08.
225 Its C<tkRunning> method now supports L<AnyEvent> event loops, and not just
226 L<Tk>. A more general mechanism has been proposed, so this may be reverted
227 before Perl 5.16 [perl #108470].
231 L<Time::HiRes> has been upgraded from version 1.9724 to version 1.9725.
233 C<Time::HiRes::stat()> no longer corrupts the Perl stack.
237 L<Unicode::UCD> has been upgraded from version 0.39 to 0.40.
239 The only change is to fix a formatting error in the Pod.
243 =head2 Removed Modules and Pragmata
255 XXX Changes to files in F<pod/> go here. Consider grouping entries by
256 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
258 =head2 New Documentation
260 XXX Changes which create B<new> files in F<pod/> go here.
262 =head3 L<perlxstypemap>
264 The new manual describes the XS typemapping mechanism in unprecedented
265 detail and combines new documentation with information extracted from
266 L<perlxs> and the previously unofficial list of all core typemaps.
270 XXX Description of the purpose of the new file here
272 =head2 Changes to Existing Documentation
274 XXX Changes which significantly change existing files in F<pod/> go here.
275 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
284 XXX Description of the change here
290 The following additions or changes have been made to diagnostic output,
291 including warnings and fatal error messages. For the complete list of
292 diagnostic messages, see L<perldiag>.
294 XXX New or changed warnings emitted by the core's C<C> code go here. Also
295 include any changes in L<perldiag> that reconcile it to the C<C> code.
297 [ Within each section, list entries as a =item entry that links to perldiag,
302 L<Invalid version object|perldiag/"Invalid version object">
305 =head2 New Diagnostics
307 XXX Newly added diagnostic messages go here
315 XXX L<message|perldiag/"message">
325 XXX L<message|perldiag/"message">
329 =head2 Changes to Existing Diagnostics
331 XXX Changes (i.e. rewording) of diagnostic messages go here
337 XXX Describe change here
341 =head1 Utility Changes
343 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
344 here. Most of these are built within the directories F<utils> and F<x2p>.
346 [ List utility changes as a =head3 entry for each utility and =item
347 entries for each change
348 Use L<XXX> with program names to get proper documentation linking. ]
360 =head1 Configuration and Compilation
362 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
363 go here. Any other changes to the Perl build process should be listed here.
364 However, any platform-specific changes should be listed in the
365 L</Platform Support> section, instead.
367 [ List changes as a =item entry ].
379 XXX Any significant changes to the testing of a freshly built perl should be
380 listed here. Changes which create B<new> files in F<t/> go here as do any
381 large changes to the testing harness (e.g. when parallel testing was added).
382 Changes to existing files in F<t/> aren't worth summarising, although the bugs
383 that they represent may be covered elsewhere.
385 [ List each test improvement as a =item entry ]
395 The test suite for typemaps has been extended to cover a larger fraction of
400 =head1 Platform Support
402 XXX Any changes to platform support should be listed in the sections below.
404 [ Within the sections, list each platform as a =item entry with specific
405 changes as paragraphs below it. ]
409 XXX List any platforms that this version of perl compiles on, that previous
410 versions did not. These will either be enabled by new files in the F<hints/>
411 directories, or new subdirectories and F<README> files at the top level of the
416 =item XXX-some-platform
422 =head2 Discontinued Platforms
424 XXX List any platforms that this version of perl no longer compiles on.
428 =item XXX-some-platform
434 =head2 Platform-Specific Notes
436 XXX List any changes for specific platforms. This could include configuration
437 and compilation changes or changes in portability/compatibility. However,
438 changes within modules for platforms should generally be listed in the
439 L</Modules and Pragmata> section.
443 =item XXX-some-platform
449 =head1 Internal Changes
451 XXX Changes which affect the interface available to C<XS> code go here.
452 Other significant internal changes for future core maintainers should
455 [ List each change as a =item entry ]
465 =head1 Selected Bug Fixes
467 XXX Important bug fixes in the core language are summarised here.
468 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
469 L</Modules and Pragmata>.
471 [ List each fix as a =item entry ]
477 C<~~> now correctly handles the precedence of Any~~Object, and is not tricked
478 by an overloaded object on the left-hand side.
482 C<stat _> no longer warns about unopened filehandles [perl #71002].
486 C<stat> on an unopened filehandle now warns consistently, instead of
487 skipping the warning at times.
491 A change in an earlier 5.15 release caused warning hints to propagate into
492 C<do $file>. This has been fixed [rt.cpan.org #72767].
496 Starting with 5.12.0, Perl used to get its internal bookkeeping muddled up
497 after assigning C<${ qr// }> to a hash element and locking it with
498 L<Hash::Util>. This could result in double frees, crashes or erratic
503 In 5.15.7, some typeglobs in the CORE namespace were made read-only by
504 mistake. This has been fixed [rt.cpan.org #74289].
508 C<-t> now works when stacked with other filetest operators [perl #77388].
512 Stacked filetest operators now only call FETCH once on a tied argument.
516 C</.*/g> would sometimes refuse to match at the end of a string that ends
517 with "\n". This has been fixed [perl #109206].
521 Method calls whose arguments were all surrounded with C<my()> or C<our()>
522 (as in C<<$object->method(my($a,$b)) >>) used to force lvalue context on
523 the subroutine. This would prevent lvalue methods from returning certain
524 values. Due to lvalue fixes earlier in the 5.15.x series, it would also
525 prevent non-lvalue methods from being called [perl #109264].
528 This bug I<did> affect earlier stable releases. It is just the last
529 sentence that does not apply to 5.14.
533 The C<SvPVutf8> C function no longer tries to modify its argument,
534 resulting in errors [perl #108994].
538 C<SvPVutf8> now works properly with magical variables.
542 C<SvPVbyte> now works properly non-PVs.
546 =head1 Known Problems
548 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
549 tests that had to be C<TODO>ed for the release would be noted here, unless
550 they were specific to a particular platform (see below).
552 This is a list of some significant unfixed bugs, which are regressions
553 from either 5.XXX.XXX or 5.XXX.XXX.
555 [ List each fix as a =item entry ]
567 XXX If any significant core contributor has died, we've added a short obituary
570 =head1 Acknowledgements
572 XXX Generate this with:
574 perl Porting/acknowledgements.pl v5.15.7..HEAD
576 =head1 Reporting Bugs
578 If you find what you think is a bug, you might check the articles
579 recently posted to the comp.lang.perl.misc newsgroup and the perl
580 bug database at http://rt.perl.org/perlbug/ . There may also be
581 information at http://www.perl.org/ , the Perl Home Page.
583 If you believe you have an unreported bug, please run the L<perlbug>
584 program included with your release. Be sure to trim your bug down
585 to a tiny but sufficient test case. Your bug report, along with the
586 output of C<perl -V>, will be sent off to perlbug@perl.org to be
587 analysed by the Perl porting team.
589 If the bug you are reporting has security implications, which make it
590 inappropriate to send to a publicly archived mailing list, then please send
591 it to perl5-security-report@perl.org. This points to a closed subscription
592 unarchived mailing list, which includes
593 all the core committers, who will be able
594 to help assess the impact of issues, figure out a resolution, and help
595 co-ordinate the release of patches to mitigate or fix the problem across all
596 platforms on which Perl is supported. Please only use this address for
597 security issues in the Perl core, not for modules independently
602 The F<Changes> file for an explanation of how to view exhaustive details
605 The F<INSTALL> file for how to build Perl.
607 The F<README> file for general stuff.
609 The F<Artistic> and F<Copying> files for copyright information.