5 [ this is a template for a new perldelta file. Any text flagged as XXX needs
6 to be processed before release. ]
8 perldelta - what is new for perl v5.21.3
12 This document describes differences between the 5.21.2 release and the 5.21.3
15 If you are upgrading from an earlier release such as 5.21.1, first read
16 L<perl5212delta>, which describes differences between 5.21.1 and 5.21.2.
20 XXX Any important notices here
22 =head1 Core Enhancements
24 =head2 C<defined(@array = LIST)> is no longer fatal
26 In 5.21.1, C<defined(@array)> was made fatal. This has been relaxed
27 to not die if the argument is assigning to an array.
31 =head2 The L<Safe> module could allow outside packages to be replaced
33 Critical bugfix: outside packages could be replaced. L<Safe> has
34 been patched to 2.38 to address this.
36 =head1 Incompatible Changes
38 =head2 S<C<use UNIVERSAL '...'>> is now a fatal error
40 Importing functions from C<UNIVERSAL> has been deprecated since v5.12, and
41 is now a fatal error. S<C<"use UNIVERSAL">> without any arguments is still
46 XXX Any deprecated features, syntax, modules etc. should be listed here.
48 [ List each other deprecation as a =head2 entry ]
50 =head1 Performance Enhancements
52 XXX Changes which enhance performance without changing behaviour go here.
53 There may well be none in a stable release.
55 [ List each enhancement as a =item entry ]
65 =head1 Modules and Pragmata
67 =head2 Updated Modules and Pragmata
73 L<B::Debug> has been upgraded from version 1.19 to 1.21
77 L<Config::Perl::V> has been upgraded from version 0.20 to 0.22.
81 L<CPAN::Meta> has been upgraded from version 2.141520 to 2.142060.
85 L<CPAN::Meta::Requirements> has been upgraded from version 2.125 to 2.126.
89 L<ExtUtils::Manifest> has been upgraded from version 1.64 to 1.65.
91 The MANIFEST is now opened with C<:raw>, to prevent C<CRLF>s leaking in.
95 L<HTTP::Tiny> has been upgraded from version 0.043 to 0.047.
99 L<perl5db.pl> has been upgraded from version 1.45 to 1.46.
101 Fixed the scope level handling of the debugger's C<y> command.
105 L<POSIX> has been upgraded from version 1.41 to 1.42.
107 Replaced the thread-unsafe code used to prevent duplicate warning
108 messages for using the isxxx() functions. [perl #122476]
112 L<Safe> has been upgraded from version 2.37 to 2.38.
114 Critical bugfix: outside packages could be replaced.
118 L<Socket> has been upgraded from version 2.014 to 2.015.
120 Test suite updates, particularly useful for Solaris and cygwin, and
121 a slight change to the pattern used for IPv4 address matching.
127 =head2 Changes to Existing Documentation
129 =head3 L<perlexperiment>
135 Added reference to L<feature>.
145 Details on C level symbols and libperl.t added.
149 =head3 L<perlhacktips>
155 Recommended replacements for tmpfile, atoi, strtol, and strtoul added.
165 ASCII v. EBCDIC clarifications added.
175 Comments added on algorithmic complexity and tied hashes.
185 Updated documentation on environment and shell interaction in VMS.
191 The following additions or changes have been made to diagnostic output,
192 including warnings and fatal error messages. For the complete list of
193 diagnostic messages, see L<perldiag>.
195 XXX New or changed warnings emitted by the core's C<C> code go here. Also
196 include any changes in L<perldiag> that reconcile it to the C<C> code.
198 =head2 New Diagnostics
200 XXX Newly added diagnostic messages go under here, separated into New Errors
209 XXX L<message|perldiag/"message">
219 L<Hexadecimal float: exponent overflow|perldiag/"Hexadecimal float: exponent overflow">
221 (W overflow) The hexadecimal floating point has larger exponent
222 than the floating point supports.
226 L<Hexadecimal float: exponent underflow|perldiag/"Hexadecimal float: exponent underflow">
228 (W overflow) The hexadecimal floating point has smaller exponent
229 than the floating point supports.
233 L<Hexadecimal float: internal error|perldiag/"Hexadecimal float: internal error">
235 (F) Something went horribly bad in hexadecimal float handling.
239 L<Hexadecimal float: mantissa overflow|perldiag/"Hexadecimal float: mantissa overflow">
241 (W overflow) The hexadecimal floating point literal had more bits in
242 the mantissa (the part between the 0x and the exponent, also known as
243 the fraction or the significand) than the floating point supports.
247 L<Hexadecimal float: precision loss|perldiag/"Hexadecimal float: precision loss">
249 (W overflow) The hexadecimal floating point had internally more
250 digits than could be output. This can be caused by unsupported
251 long double formats, or by 64-bit integers not being available
252 (needed to retrieve the digits under some configurations).
256 L<Hexadecimal float: unsupported long double format|perldiag/"Hexadecimal float: unsupported long double format">
258 (F) You have configured Perl to use long doubles but
259 the internals of the long double format are unknown,
260 therefore the hexadecimal float output is impossible.
264 =head2 Changes to Existing Diagnostics
266 XXX Changes (i.e. rewording) of diagnostic messages go here
272 XXX Describe change here
276 =head1 Configuration and Compilation
278 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
279 go here. Any other changes to the Perl build process should be listed here.
280 However, any platform-specific changes should be listed in the
281 L</Platform Support> section, instead.
283 [ List changes as a =item entry ].
289 Internal handling of floating point values has been improved.
295 XXX Any significant changes to the testing of a freshly built perl should be
296 listed here. Changes which create B<new> files in F<t/> go here as do any
297 large changes to the testing harness (e.g. when parallel testing was added).
298 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
299 that they represent may be covered elsewhere.
301 [ List each test improvement as a =item entry ]
311 =head1 Platform Support
313 XXX Any changes to platform support should be listed in the sections below.
315 [ Within the sections, list each platform as a =item entry with specific
316 changes as paragraphs below it. ]
318 =head2 Platform-Specific Notes
320 XXX List any changes for specific platforms. This could include configuration
321 and compilation changes or changes in portability/compatibility. However,
322 changes within modules for platforms should generally be listed in the
323 L</Modules and Pragmata> section.
327 =item XXX-some-platform
333 =head1 Internal Changes
335 XXX Changes which affect the interface available to C<XS> code go here. Other
336 significant internal changes for future core maintainers should be noted as
339 [ List each change as a =item entry ]
345 Added L<perlapi/sync_locale>.
346 Changing the program's locale should be avoided by XS code. Nevertheless,
347 certain non-Perl libraries called from XS, such as C<Gtk> do so. When this
348 happens, Perl needs to be told that the locale has changed. Use this function
349 to do so, before returning to Perl.
353 =head1 Selected Bug Fixes
355 XXX Important bug fixes in the core language are summarized here. Bug fixes in
356 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
358 [ List each fix as a =item entry ]
364 Failing to compile C<use Foo> in an eval could leave a spurious
365 C<BEGIN> subroutine definition, which would produce a "Subroutine
366 BEGIN redefined" warning on the next use of C<use>, or other C<BEGIN>
367 block. [perl #122107]
371 C<method { BLOCK } ARGS> syntax now correctly parses the arguments if they
372 begin with an opening brace. [perl #46947]
376 =head1 Known Problems
378 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
379 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
380 platform specific bugs also go here.
382 [ List each fix as a =item entry ]
392 =head1 Errata From Previous Releases
398 XXX Add anything here that we forgot to add, or were mistaken about, in
399 the perldelta of a previous release.
403 =head1 Acknowledgements
405 XXX Generate this with:
407 perl Porting/acknowledgements.pl v5.21.2..HEAD
409 =head1 Reporting Bugs
411 If you find what you think is a bug, you might check the articles recently
412 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
413 https://rt.perl.org/ . There may also be information at
414 http://www.perl.org/ , the Perl Home Page.
416 If you believe you have an unreported bug, please run the L<perlbug> program
417 included with your release. Be sure to trim your bug down to a tiny but
418 sufficient test case. Your bug report, along with the output of C<perl -V>,
419 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
421 If the bug you are reporting has security implications, which make it
422 inappropriate to send to a publicly archived mailing list, then please send it
423 to perl5-security-report@perl.org. This points to a closed subscription
424 unarchived mailing list, which includes all the core committers, who will be
425 able to help assess the impact of issues, figure out a resolution, and help
426 co-ordinate the release of patches to mitigate or fix the problem across all
427 platforms on which Perl is supported. Please only use this address for
428 security issues in the Perl core, not for modules independently distributed on
433 The F<Changes> file for an explanation of how to view exhaustive details on
436 The F<INSTALL> file for how to build Perl.
438 The F<README> file for general stuff.
440 The F<Artistic> and F<Copying> files for copyright information.