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 v5.19.4
12 This document describes differences between the 5.19.3 release and the 5.19.4
15 If you are upgrading from an earlier release such as 5.19.2, first read
16 L<perl5193delta>, which describes differences between 5.19.2 and 5.19.3.
20 XXX Any important notices here
22 =head1 Core Enhancements
24 XXX New core language features go here. Summarize user-visible core language
25 enhancements. Particularly prominent performance optimisations could go
26 here, but most should go in the L</Performance Enhancements> section.
28 [ List each enhancement as a =head2 entry ]
30 =head2 rand() now uses a consistent random number generator
32 Previously perl would use a platform specific random number generator,
33 varying between the libc C<rand()>, C<random()> or C<drand48()>.
35 This meant that the quality of perl's random numbers would vary from
36 platform to platform, from the 15 bits of C<rand()> on Win32 to
37 48-bits on POSIX platforms such as Linux with C<drand48()>.
39 Perl now uses its own internal C<drand48()> implementation on all
40 platforms. [perl #115928]
44 XXX Any security-related notices go here. In particular, any security
45 vulnerabilities closed should be noted here rather than in the
46 L</Selected Bug Fixes> section.
48 [ List each security issue as a =head2 entry ]
50 =head1 Incompatible Changes
52 =head2 Locale decimal point character no longer leaks outside of
53 S<C<use locale>> scope (with the exception of C<$!>)
55 This is actually a bug fix, but some code has come to rely on the bug being
56 present, so this change is listed here. The current locale that the program is
57 running under is not supposed to be visible to Perl code except within the
58 scope of a S<C<use locale>>. However, until now under certain circumstances,
59 the character used for a decimal point (often a comma) leaked outside the
62 This continues the work released in Perl 5.19.1. It turns out that that did
63 not catch all the leaks, including C<printf> and C<sprintf> not respecting
64 S<C<use locale>>. If your code is affected by this change, simply add a
67 Now, the only known place where C<'use locale'> is not respected is in the
68 stringification of L<$!|perlvar/$!>.
72 XXX Any deprecated features, syntax, modules etc. should be listed here.
74 =head2 Module removals
76 XXX Remove this section if inapplicable.
78 The following modules will be removed from the core distribution in a
79 future release, and will at that time need to be installed from CPAN.
80 Distributions on CPAN which require these modules will need to list them as
83 The core versions of these modules will now issue C<"deprecated">-category
84 warnings to alert you to this fact. To silence these deprecation warnings,
85 install the modules in question from CPAN.
87 Note that these are (with rare exceptions) fine modules that you are encouraged
88 to continue to use. Their disinclusion from core primarily hinges on their
89 necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
90 not usually on concerns over their design.
94 XXX Note that deprecated modules should be listed here even if they are listed
95 as an updated module in the L</Modules and Pragmata> section.
99 [ List each other deprecation as a =head2 entry ]
101 =head1 Performance Enhancements
107 The trie performance enhancement for regular expressions has now been extended
108 to those compiled under C</iaa>.
112 =head1 Modules and Pragmata
114 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
115 go here. If Module::CoreList is updated, generate an initial draft of the
116 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
117 entries to STDOUT. Results can be pasted in place of the '=head2' entries
118 below. A paragraph summary for important changes should then be added by hand.
119 In an ideal world, dual-life modules would have a F<Changes> file that could be
122 [ Within each section, list entries as a =item entry ]
124 =head2 New Modules and Pragmata
134 =head2 Updated Modules and Pragmata
140 L<autodie> has been upgraded from version 2.20 to 2.21.
142 Numerous improvements have been made, many speed-related. See the F<Changes>
143 file in the CPAN distribution for full details.
147 L<B> has been upgraded from version 1.45 to 1.46.
149 The fix for [perl #118525] introduced a regression in the behaviour of
150 C<B::CV::GV>, changing the return value from a C<B::SPECIAL> object on a
151 C<NULL> C<CvGV> to C<undef>. C<B::CV::GV> again returns a C<B::SPECIAL>
152 object in this case. [perl #119351]
156 L<B::Concise> has been upgraded from version 0.98 to 0.99.
158 The handling of the C<glob> operator, broken since Perl 5.17.6, has been fixed.
162 L<Carp> has been upgraded from version 1.31 to 1.32.
168 In stack traces, subroutine arguments that are strings are now quoted in a
169 consistent manner, regardless of what characters they contain and how they're
170 internally represented.
174 C<Carp> now won't vivify the C<overload::StrVal> glob or subroutine or the
179 C<Carp> now avoids some unwanted Unicode warnings on older Perls. This doesn't
180 affect behaviour with current Perl.
184 C<Carp::Heavy> detects version mismatch with C<Carp>, to give a good error
185 message if a current (stub) C<Carp::Heavy> gets loaded by an old C<Carp> that
186 expects C<Carp::Heavy> to provide subroutines.
192 L<charnames> has been upgraded from version 1.38 to 1.39.
194 This module now works on EBCDIC platforms.
198 L<CPAN::Meta> has been upgraded from version 2.132140 to 2.132510.
200 No changes have been made to the installed code other than the version bump to
201 keep in sync with the latest CPAN release.
205 L<CPAN::Meta::Requirements> has been upgraded from version 2.122 to 2.123.
207 No changes have been made to the installed code other than the version bump to
208 keep in sync with the latest CPAN release.
212 L<Data::Dumper> has been upgraded from version 2.148 to 2.149.
214 This upgrade is part of a larger change to make the array interface 64-bit safe
215 by using SSize_t instead of I32 for array indices.
217 In addition, an EBCDIC fix has been applied.
221 L<Devel::Peek> has been upgraded from version 1.13 to 1.14.
223 This upgrade is part of a larger change to preserve referential identity when
224 passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
225 nonexistent array elements.
227 In addition, C<Dump> with no args was broken in Perl 5.19.3, but has now been
232 L<DynaLoader> has been upgraded from version 1.19 to 1.20.
234 The documentation now makes it clear, as has always been the case, that
235 C<dl_unload_file> is only called automatically to unload all loaded shared
236 objects if the perl interpreter was built with the C macro
237 DL_UNLOAD_ALL_AT_EXIT defined. Support for GNU DLD has also been removed.
241 L<Encode> has been upgraded from version 2.52 to 2.54.
243 An erroneous early return in C<decode_utf8> has been removed, and a bug in
244 C<_utf8_on> under COW has been fixed.
248 L<Exporter> has been upgraded from version 5.69 to 5.70.
250 A number of typos have been corrected in the documentation.
254 L<ExtUtils::CBuilder> has been upgraded from version 0.280205 to 0.280212.
256 No changes have been made to the installed code other than the version bump to
257 keep in sync with the latest CPAN release.
261 L<ExtUtils::Command> has been upgraded from version 1.17 to 1.18.
263 No changes have been made to the installed code other than the version bump to
264 keep in sync with the latest CPAN release.
268 L<ExtUtils::MakeMaker> has been upgraded from version 6.72 to 6.76.
270 Numerous updates and bug fixes are incorporated. See the F<Changes> file for
275 L<ExtUtils::ParseXS> has been upgraded from version 3.21 to 3.22.
277 No changes have been made to the installed code other than the version bump to
278 keep in sync with the latest CPAN release.
282 L<File::Find> has been upgraded from version 1.24 to 1.25.
284 Better diagnostics are now provided in the case of a failed C<chdir>.
288 L<File::Glob> has been upgraded from version 1.20 to 1.21.
290 C<glob()> now warns in the context of C<use warnings "syscalls";> if the
291 supplied pattern has an internal NUL (C<"\0">) character.
295 L<HTTP::Tiny> has been upgraded from version 0.034 to 0.035.
297 Encoded data from C<post_form> now preserves term order if data is provided as
298 an array reference. (They are still sorted for consistency if provided as a
303 L<I18N::LangTags> has been upgraded from version 0.39 to 0.40.
305 Bosnian has now joined Croatian and Serbian in the lists of mutually
306 intelligible Slavic languages. [perl #72594]
310 L<IO> has been upgraded from version 1.28 to 1.29.
312 A minor internals-only change has been made to the XS code.
316 L<IPC::Open3> has been upgraded from version 1.15 to 1.16.
318 This upgrade is part of a larger change to preserve referential identity when
319 passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
320 nonexistent array elements.
324 L<Locale::Codes> has been upgraded from version 3.26 to 3.27.
326 New codes have been added and the (deprecated) set of FIPS-10 country codes has
331 L<Math::BigInt> has been upgraded from version 1.9992 to 1.9993.
333 Cleaned up the L<Math::BigInt> and L<Math::BigFloat> documentation to be more
334 consistent with other perl documentation. [perl #86686]
336 Added a bint() method for rounding towards zero. [perl #85296]
340 L<Math::BigInt::FastCalc> has been upgraded from version 0.30 to 0.31.
342 This upgrade is part of a larger change to make the array interface 64-bit safe
343 by using SSize_t instead of I32 for array indices.
347 L<Module::CoreList> has been upgraded from version 2.97 to 2.98.
349 The list of Perl versions covered has been updated.
353 L<Module::Load::Conditional> has been upgraded from version 0.54 to 0.58.
355 C<requires> has been made more robust. [cpan #83728]
359 L<Module::Metadata> has been upgraded from version 1.000014 to 1.000018.
361 The module's DESCRIPTION has been re-worded regarding safety/security to
362 satisfy CVE-2013-1437. Also, versions are now detainted if needed. [cpan
367 L<mro> has been upgraded from version 1.13 to 1.14.
369 This upgrade is part of a larger change to make the array interface 64-bit safe
370 by using SSize_t instead of I32 for array indices.
374 L<parent> has been upgraded from version 0.226 to 0.227.
376 No changes have been made to the installed code other than the version bump to
377 keep in sync with the latest CPAN release.
381 L<Parse::CPAN::Meta> has been upgraded from version 1.4405 to 1.4407.
383 No changes have been made to the installed code other than the version bump to
384 keep in sync with the latest CPAN release.
388 L<Perl::OSType> has been upgraded from version 1.003 to 1.005.
390 The Unix OSType 'bitrig' has been added.
394 L<perlfaq> has been upgraded from version 5.0150043 to 5.0150044.
396 The use of C<gensym> in a number of examples has been removed, the use of C<&>
397 in subroutine calls is now clarified and several new questions have been
402 L<re> has been upgraded from version 0.25 to 0.26.
404 A function signature has been corrected in the XS implementation.
408 L<Scalar::Util> has been upgraded from version 1.31 to 1.32.
410 The documentation of C<blessed> has been improved to mention the fact that
411 package "0" is defined but false.
415 L<Socket> has been upgraded from version 2.011 to 2.012.
417 Syntax errors when building on the WinCE platform have been fixed. [cpan #87389]
421 L<Storable> has been upgraded from version 2.46 to 2.47.
423 This upgrade is part of a larger change to preserve referential identity when
424 passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
425 nonexistent array elements.
429 L<Term::ReadLine> has been upgraded from version 1.10 to 1.14.
431 Term::ReadLine::EditLine support has been added.
435 L<Time::Piece> has been upgraded from version 1.22 to 1.23.
437 Day of year parsing (like "%y%j") has been fixed.
441 L<Unicode::Collate> has been upgraded from version 0.98 to 0.99.
443 By default, out-of-range values are replaced with C<U+FFFD> (REPLACEMENT
444 CHARACTER) when C<UCA_Version> E<gt>= 22, or ignored when C<UCA_Version> E<lt>=
445 20. When C<UCA_Version> E<gt>= 22, the weights of out-of-range values can be
450 L<Unicode::UCD> has been upgraded from version 0.53 to 0.54.
452 This module now works on EBCDIC platforms.
456 L<version> has been upgraded from version 0.9903 to 0.9904.
458 No changes have been made to the installed code other than the version bump to
459 keep in sync with the latest CPAN release.
463 L<warnings> has been upgraded from version 1.18 to 1.19.
465 The C<syscalls> warnings category has been added to check for embedded NUL
466 (C<"\0">) characters in pathnames and string arguments to other system calls.
470 L<XS::Typemap> has been upgraded from version 0.10 to 0.11.
474 =head2 Removed Modules and Pragmata
486 XXX Changes to files in F<pod/> go here. Consider grouping entries by
487 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
489 =head2 New Documentation
491 XXX Changes which create B<new> files in F<pod/> go here.
495 XXX Description of the purpose of the new file here
497 =head2 Changes to Existing Documentation
499 XXX Changes which significantly change existing files in F<pod/> go here.
500 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
509 XXX Description of the change here
515 The following additions or changes have been made to diagnostic output,
516 including warnings and fatal error messages. For the complete list of
517 diagnostic messages, see L<perldiag>.
519 XXX New or changed warnings emitted by the core's C<C> code go here. Also
520 include any changes in L<perldiag> that reconcile it to the C<C> code.
522 =head2 New Diagnostics
524 XXX Newly added diagnostic messages go under here, separated into New Errors
533 XXX L<message|perldiag/"message">
543 L<Invalid \0 character in %s for %s: %s\0%s|perldiag/"Invalid \0 character in %s for %s: %s\0%s">
545 (W syscalls) Embedded \0 characters in pathnames or other system call arguments
546 produce a warning as of 5.20. The parts after the \0 were formerly ignored by
551 =head2 Changes to Existing Diagnostics
553 XXX Changes (i.e. rewording) of diagnostic messages go here
559 Warnings and errors from the regexp engine are now UTF-8 clean
563 The "Unknown switch condition" error message has some slight changes.
564 This error triggers when there is an unknown condition in a (?(foo))
565 conditional; The error message used to read:
567 Unknown switch condition (?(%s in regex;
569 But what %s could be was mostly up to luck; For (?(foobar)), you
570 might've seen "fo" or "f". For Unicode characters, you'd generally
571 get a corrupted string.
572 The message was changed to read:
574 Unknown switch condition (?(...)) in regex;
576 And additionally, the '<-- HERE' marker in the error will now point
577 to the correct spot in the regex.
581 =head1 Utility Changes
583 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
584 Most of these are built within the directories F<utils> and F<x2p>.
586 [ List utility changes as a =head3 entry for each utility and =item
587 entries for each change
588 Use L<XXX> with program names to get proper documentation linking. ]
596 L<find2perl> now handles C<?> wildcards correctly. [perl #113054]
600 =head1 Configuration and Compilation
602 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
603 go here. Any other changes to the Perl build process should be listed here.
604 However, any platform-specific changes should be listed in the
605 L</Platform Support> section, instead.
607 [ List changes as a =item entry ].
613 The F<Makefile.PL> for C<SDBM_File> now generates a better F<Makefile>, which
614 avoids a race condition during parallel makes, which could cause the build to
615 fail. This is the last known parallel make problem (on *nix platforms), and
616 therefore we believe that a parallel make should now always be error free.
620 Strictly only for a build where build files such as F<Makefile.SH> have not
621 been updated by C<git> in an already configured and built tree.
627 XXX Any significant changes to the testing of a freshly built perl should be
628 listed here. Changes which create B<new> files in F<t/> go here as do any
629 large changes to the testing harness (e.g. when parallel testing was added).
630 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
631 that they represent may be covered elsewhere.
633 [ List each test improvement as a =item entry ]
639 The test script F<t/bigmem/regexp.t> has been added to test that regular
640 expression matches on very large strings now succeed as expected.
644 Various cases of C<die>, C<last>, C<goto> and C<exit> triggering C<DESTROY> are
645 now tested by the new test script F<t/op/rt119311.t>.
649 The new test script F<t/win32/signal.t> tests that C<$!> and C<$^E> are now
650 preserved across signal handlers by the Win32 signal emulation code.
654 The test script F<t/x2p/find2perl.t> has been added to test the F<find2perl>
655 program on platforms where it is practical to do so.
659 =head1 Platform Support
661 XXX Any changes to platform support should be listed in the sections below.
663 [ Within the sections, list each platform as a =item entry with specific
664 changes as paragraphs below it. ]
668 XXX List any platforms that this version of perl compiles on, that previous
669 versions did not. These will either be enabled by new files in the F<hints/>
670 directories, or new subdirectories and F<README> files at the top level of the
677 Compile support has been added for Bitrig, a fork of OpenBSD
681 =head2 Discontinued Platforms
683 XXX List any platforms that this version of perl no longer compiles on.
685 Configure hints and conditional code for several very old platforms
686 has been removed. We have not received reports for these in many years,
687 typically not since perl-5.6.0.
693 Configure support for the 3b1, also known as the AT&T Unix PC (and the
694 similar AT&T 7300), has been removed.
698 =head2 Platform-Specific Notes
700 XXX List any changes for specific platforms. This could include configuration
701 and compilation changes or changes in portability/compatibility. However,
702 changes within modules for platforms should generally be listed in the
703 L</Modules and Pragmata> section.
709 The building of XS modules has largely been restored. Several still cannot
710 (yet) be built but it is now possible to build Perl on WinCE with only a couple
711 of further patches (to L<Socket> and L<ExtUtils::MakeMaker>), hopefully to be
716 =head1 Internal Changes
718 XXX Changes which affect the interface available to C<XS> code go here. Other
719 significant internal changes for future core maintainers should be noted as
722 [ List each change as a =item entry ]
728 The internal representation has changed for the match variables C<$1>, C<$2>
729 I<etc.>, C<$`>, C<$&>, C<$'>, C<${^PREMATCH}>, C<${^MATCH}> and
730 C<${^POSTMATCH>. It uses slightly less memory, avoids string comparisons
731 and numeric conversions during lookup, and uses 23 fewer lines of C. This
732 change should not affect any external code.
736 =head1 Selected Bug Fixes
738 XXX Important bug fixes in the core language are summarized here. Bug fixes in
739 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
741 [ List each fix as a =item entry ]
747 The value of C<$^E> is now saved across signal handlers on Win32. [perl #85104]
751 =head1 Known Problems
753 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
754 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
755 platform specific bugs also go here.
757 [ List each fix as a =item entry ]
769 XXX If any significant core contributor has died, we've added a short obituary
772 =head1 Acknowledgements
774 XXX Generate this with:
776 perl Porting/acknowledgements.pl v5.19.3..HEAD
778 =head1 Reporting Bugs
780 If you find what you think is a bug, you might check the articles recently
781 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
782 http://rt.perl.org/perlbug/ . There may also be information at
783 http://www.perl.org/ , the Perl Home Page.
785 If you believe you have an unreported bug, please run the L<perlbug> program
786 included with your release. Be sure to trim your bug down to a tiny but
787 sufficient test case. Your bug report, along with the output of C<perl -V>,
788 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
790 If the bug you are reporting has security implications, which make it
791 inappropriate to send to a publicly archived mailing list, then please send it
792 to perl5-security-report@perl.org. This points to a closed subscription
793 unarchived mailing list, which includes all the core committers, who will be
794 able to help assess the impact of issues, figure out a resolution, and help
795 co-ordinate the release of patches to mitigate or fix the problem across all
796 platforms on which Perl is supported. Please only use this address for
797 security issues in the Perl core, not for modules independently distributed on
802 The F<Changes> file for an explanation of how to view exhaustive details on
805 The F<INSTALL> file for how to build Perl.
807 The F<README> file for general stuff.
809 The F<Artistic> and F<Copying> files for copyright information.