5 [ this is a template for a new perldelta file. Any text flagged as
6 XXX needs to be processed before release. ]
8 perldelta - what is new for perl v5.13.10
12 This document describes differences between the 5.XXX.XXX release and
13 the 5.XXX.XXX release.
15 If you are upgrading from an earlier release such as 5.YYY.YYY, first read
16 L<perl5YYYdelta>, which describes differences between 5.ZZZ.ZZZ and
21 XXX Any important notices here
23 =head1 Core Enhancements
25 XXX New core language features go here. Summarise user-visible core language
26 enhancements. Particularly prominent performance optimisations could go
27 here, but most should go in the L</Performance Enhancements> section.
29 [ List each enhancement as a =head2 entry ]
31 =head2 Add C<\p{Titlecase}> as a synonym for C<\p{Title}>
33 This synonym is added for symmetry with the Unicode property names
34 C<\p{Uppercase}> and C<\p{Lowercase}>.
36 =head2 New regular expression modifier option C</aa>
38 Doubling the C</a> regular expression modifier increases its effect,
39 so that in case-insensitive matching, no ASCII character will match a
40 non-ASCII character. For example, normally,
42 'k' =~ /\N{KELVIN SIGN}/
44 will match; it won't under C</aa>. Note that like C</a>, C</aa>
45 in 5.14 will not actually be able to be used as a suffix at the end of a
50 XXX Any security-related notices go here. In particular, any security
51 vulnerabilities closed should be noted here rather than in the
52 L</Selected Bug Fixes> section.
54 [ List each security issue as a =head2 entry ]
56 =head1 Incompatible Changes
58 XXX For a release on a stable branch, this section aspires to be:
60 There are no changes intentionally incompatible with 5.XXX.XXX. If any
61 exist, they are bugs and reports are welcome.
63 [ List each incompatible change as a =head2 entry ]
65 =head2 Most C<\p{}> properties are now immune from case-insensitive matching
67 For most Unicode properties, it doesn't make sense to have them match
68 differently under C</i> case-insensitive matching than not. And doing
69 so leads to unexpected results and potential security holes. For
72 m/\p{ASCII_Hex_Digit}+/i
74 could previously match non-ASCII characters because of the Unicode
75 matching rules. There were a number of bugs in this feature until an
76 earlier release in the 5.13 series. Now this release reverts, and
77 removes the feature completely except for the few properties where
78 people have come to expect it, namely the ones where casing is an
79 integral part of their functionality, such as C<m/\p{Uppercase}/i> and
80 C<m/\p{Lowercase}/i>, both of which match the exact same code points,
81 namely those matched by C<m/\p{Cased}/i>. Details are in
82 L<perlrecharclass/Unicode Properties>.
84 User-defined property handlers that need to match differently under
85 C</i> must change to read the new boolean parameter passed it which is
86 non-zero if case-insensitive matching is in effect; 0 if not. See
87 L<perluniprops/User-Defined Character Properties>.
89 =head2 [perl #82996] Use the user's from address as return-path in perlbug
91 Many systems these days don't have a valid Internet domain name and
92 perlbug@perl.org does not accept email with a return-path that does
93 not resolve. Therefore pass the user's address to sendmail so it's
94 less likely to get stuck in a mail queue somewhere. (019cfd2)
96 =head2 regex: \p{} in pattern implies Unicode semantics
98 Now, a Unicode property match specified in the pattern will indicate
99 that the pattern is meant for matching according to Unicode rules
102 =head2 add GvCV_set() and GvGP_set() macros and change GvGP()
104 This allows a future commit to eliminate some backref magic between GV
105 and CVs, which will require complete control over assignment to the
108 If you've been using GvGP() in lvalue context this change will break
109 your code, you should use GvGP_set() instead. (c43ae56)
111 =head2 _swash_inversion_hash is no longer exported as part of the API
113 This function shouldn't be called from XS code. (4c2e113)
115 =head2 Unreferenced objects in global destruction
117 The fix for [perl #36347], which made sure that destructors were called on
118 unreferenced objects, broke the tests for three CPAN modules, which
119 apparently rely on the bug.
121 To provide more time for fixing them (as this is such a minor bug), we
122 have reverted the fix until after perl 5.14.0.
124 This resolves [perl #82542] and other related tickets.
126 =head2 C<close> on shared pipes
128 The C<close> function no longer waits for the child process to exit if the
129 underlying file descriptor is still in use by another thread, to avoid
130 deadlocks. It returns true in such cases.
134 XXX Any deprecated features, syntax, modules etc. should be listed here.
135 In particular, deprecated modules should be listed here even if they are
136 listed as an updated module in the L</Modules and Pragmata> section.
138 [ List each deprecation as a =head2 entry ]
140 =head1 Performance Enhancements
142 XXX Changes which enhance performance without changing behaviour go here. There
143 may well be none in a stable release.
145 [ List each enhancement as a =item entry ]
155 =head1 Modules and Pragmata
157 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
158 go here. If Module::CoreList is updated, generate an initial draft of the
159 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
160 entries to STDOUT. Results can be pasted in place of the '=head2' entries
161 below. A paragraph summary for important changes should then be added by hand.
162 In an ideal world, dual-life modules would have a F<Changes> file that could be
165 [ Within each section, list entries as a =item entry ]
167 =head2 New Modules and Pragmata
173 C<CPAN::Meta> version 2.110440 has been added as a dual-life module. It
174 provides a standard library to read, interpret and write CPAN distribution
175 metadata files (e.g. META.json and META.yml) which describes a
176 distribution, its contents, and the requirements for building it and
177 installing it. The latest CPAN distribution metadata specification is
178 included as C<CPAN::Meta::Spec> and notes on changes in the specification
179 over time are given in C<CPAN::Meta::History>.
183 C<Version::Requirements> version 0.101020 has been added as a dual-life
184 module. It provides a standard library to model and manipulates module
185 prerequisites and version constraints as defined in the L<CPAN::Meta::Spec>.
189 =head2 Updated Modules and Pragmata
195 C<B> has been upgraded from version 1.27 to 1.28.
199 C<Carp> has been upgraded from version 1.19 to 1.20.
201 [perl #82854] It now avoids using regular expressions that cause perl to
202 load its Unicode tables, in order to avoid the 'BEGIN not safe after
203 errors' error that will ensue if there has been a syntax error.
207 C<CGI> has been upgraded from version 3.51 to 3.52
211 C<CPANPLUS> has been upgraded from version 0.9011 to 0.9101
213 Includes support for META.json and MYMETA.json and a change to
214 using Digest::SHA for CPAN checksums.
218 C<diagnostics> has been upgraded from version 1.21 to 1.22.
220 It now renders pod links slightly better, and has been taught to find
221 descriptions for messages that share their descriptions with other
226 C<IO::Select> has been upgraded from version 1.17 to 1.18.
228 It now allows IO::Handle objects (and objects in derived classes) to be
229 removed from an IO::Select set even if the underlying file descriptor is
234 C<IPC::Cmd> has been upgraded from version 0.68 to 0.70
238 C<HTTP::Tiny> has been upgraded from version 0.009 to 0.010
242 C<Math::BigInt> has been upgraded from version 1.99_04 to 1.991.
246 C<Module::Build> has been upgraded from version 0.3607 to 0.3622.
248 A notable change is the deprecation of several modules.
249 Module::Build::Version has been deprecated and Module::Build now relies
250 directly upon L<version>. Module::Build::ModuleInfo has been deprecated in
251 favor of a standalone copy of it called L<Module::Metadata>.
252 Module::Build::YAML has been deprecated in favor of L<CPAN::Meta::YAML>.
256 C<Module::Load::Conditional> has been upgraded from version 0.40 to 0.44
260 C<Module::Metadata> has been upgraded from version 1.000003 to 1.000004.
264 C<overload> has been upgraded from version 1.12 to 1.13.
266 The documentation has greatly improved. See L</Documentation> below.
270 C<Parse::CPAN::Meta> has been upgraded from version 1.40 to 1.4401.
272 The latest Parse::CPAN::Meta can now read YAML or JSON files using
273 L<CPAN::Meta::YAML> and L<JSON::PP>, which are now part of the Perl core.
277 C<re> has been upgraded from version 0.16 to 0.17.
279 It now supports the double-a flag: C<use re '/aa';>
283 C<Term::UI> has been upgraded from version 0.24 to 0.26
287 C<Unicode::Collate> has been upgraded from version 0.68 to 0.72
289 This also sees the switch from using the pure-perl version of this
290 module to the XS version.`
294 C<VMS::DCLsym> has been upgraded from version 1.04 to 1.05.
296 Two bugs have been fixed [perl #84086]:
298 The symbol table name was lost when tying a hash, due to a thinko in
299 C<TIEHASH>. The result was that all tied hashes interacted with the
302 Unless a symbol table name had been explicitly specified in the call
303 to the constructor, querying the special key ':LOCAL' failed to
304 identify objects connected to the local symbol table.
308 Added new function C<Unicode::UCD::num()>. This function will return the
309 numeric value of the string passed it; C<undef> if the string in its
310 entirety has no safe numeric value.
312 To be safe, a string must be a single character which has a numeric
313 value, or consist entirely of characters that match \d, coming from the
314 same Unicode block of digits. Thus, a mix of Bengali and Western
315 digits would be considered unsafe, as well as a mix of half- and
316 full-width digits, but strings consisting entirely of Devanagari digits
317 or of "Mathematical Bold" digits would would be safe.
321 C<CPAN> has been upgraded from version1.94_63 to 1.94_64.
329 =head2 Removed Modules and Pragmata
341 XXX Changes to files in F<pod/> go here. Consider grouping entries by
342 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
344 =head2 New Documentation
346 XXX Changes which create B<new> files in F<pod/> go here.
350 XXX Description of the purpose of the new file here
352 =head2 Changes to Existing Documentation
354 XXX Changes which significantly change existing files in F<pod/> go here.
355 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
364 L<overload>'s documentation has practically undergone a rewrite. It
365 is now much more straightforward and clear.
369 =head3 L<perlhack> and perlrepository
375 The L<perlhack> and perlrepository documents have been heavily edited and
376 split up into several new documents.
378 The L<perlhack> document is now much shorter, and focuses on the Perl 5
379 development process and submitting patches to Perl. The technical content has
380 been moved to several new documents, L<perlsource>, L<perlinterp>,
381 L<perlhacktut>, and L<perlhacktips>. This technical content has only been
384 The perlrepository document has been renamed to L<perlgit>. This new document
385 is just a how-to on using git with the Perl source code. Any other content
386 that used to be in perlrepository has been moved to perlhack.
396 The documentation for the C<map> function now contains more examples,
397 see B<perldoc -f map> (f947627)
407 Examples in L<perlfaq4> have been updated to show the use of
408 L<Time::Piece>. (9243591)
418 Many POD related RT bugs and other issues which are too numerous to
419 enumerate have been solved by Michael Stevens.
425 The following additions or changes have been made to diagnostic output,
426 including warnings and fatal error messages. For the complete list of
427 diagnostic messages, see L<perldiag>.
429 XXX New or changed warnings emitted by the core's C<C> code go here. Also
430 include any changes in L<perldiag> that reconcile it to the C<C> code.
432 [ Within each section, list entries as a =item entry ]
434 =head2 New Diagnostics
436 XXX Newly added diagnostic messages go here
440 =item "\b{" is deprecated; use "\b\{" instead
442 =item "\B{" is deprecated; use "\B\{" instead
444 Use of an unescaped "{" immediately following a C<\b> or C<\B> is now
445 deprecated so as to reserve its use for Perl itself in a future release.
447 =item regcomp: Add warning if \p is used under locale. (fb2e24c)
449 C<\p> implies Unicode matching rules, which are likely going to be
450 different than the locale's.
452 =item panic: gp_free failed to free glob pointer - something is repeatedly re-creating entries
454 This new error is triggered if a destructor called on an object in a
455 typeglob that is being freed creates a new typeglob entry containing an
456 object with a destructor that creates a new entry containing an object....
458 =item refcnt: fd %d%s
460 This new error only occurs if a internal consistency check fails when a
461 pipe is about to be closed.
465 =head2 Changes to Existing Diagnostics
467 XXX Changes (i.e. rewording) of diagnostic messages go here
473 The warning message about regex unrecognized escapes passed through is
474 changed to include any literal '{' following the 2-char escape. e.g.,
475 "\q{" will include the { in the message as part of the escape
478 =item * C<binmode $fh, ':scalar'> no longer warns (8250589)
480 Perl will now no longer produce this warning:
482 $ perl -we 'open my $f, ">", \my $x; binmode $f, "scalar"'
483 Use of uninitialized value in binmode at -e line 1.
491 =head1 Utility Changes
493 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
494 here. Most of these are built within the directories F<utils> and F<x2p>.
496 [ List utility changes as a =head3 entry for each utility and =item
497 entries for each change
498 Use L<XXX> with program names to get proper documentation linking. ]
510 =head1 Configuration and Compilation
512 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
513 go here. Any other changes to the Perl build process should be listed here.
514 However, any platform-specific changes should be listed in the
515 L</Platform Support> section, instead.
517 [ List changes as a =item entry ].
521 =item * make reg_eval_scope.t TODOs consistently fail (daaf7ac)
523 Some of the TODO tests in reg_eval_scope.t spuriously passed under
524 non-threaded builds. Make the tests harder so they always fail.
526 Since one of the key bugs in (?{..}) is the trashing of the parent pad,
527 add some extra lexical vars to the parent scope and check they're still
532 Stop EU::CBuilder's tests from failing in parallel (cbf59d5)
534 It used to use the same paths for temporary files in all tests. This
535 blew up randomly when the tests were run in parallel.
545 XXX Any significant changes to the testing of a freshly built perl should be
546 listed here. Changes which create B<new> files in F<t/> go here as do any
547 large changes to the testing harness (e.g. when parallel testing was added).
548 Changes to existing files in F<t/> aren't worth summarising, although the bugs
549 that they represent may be covered elsewhere.
551 [ List each test improvement as a =item entry ]
557 F<porting/FindExt.t> now skips all tests on a static (-Uusedl) build
562 F<porting/FindExt.t> now passes on non-Win32 platforms when some
563 extensions are built statically.
567 =head1 Platform Support
569 XXX Any changes to platform support should be listed in the sections below.
571 [ Within the sections, list each platform as a =item entry with specific
572 changes as paragraphs below it. ]
576 XXX List any platforms that this version of perl compiles on, that previous
577 versions did not. These will either be enabled by new files in the F<hints/>
578 directories, or new subdirectories and F<README> files at the top level of the
583 =item XXX-some-platform
589 =head2 Discontinued Platforms
591 XXX List any platforms that this version of perl no longer compiles on.
595 =item XXX-some-platform
601 =head2 Platform-Specific Notes
603 XXX List any changes for specific platforms. This could include configuration
604 and compilation changes or changes in portability/compatibility. However,
605 changes within modules for platforms should generally be listed in the
606 L</Modules and Pragmata> section.
616 The C<test-prep> build target now depends on F<pod/perltoc.pod> to allow the
617 F<t/porting/buildtoc.t> test to run successfully.
627 [perl #82988] Skip hanging taint.t test on MirBSD 10 (1fb83d0)
629 Skip a hanging test under MirBSD that was already being skipped under
634 Previously if you build perl with a shared libperl.so on MirBSD (the
635 default config), it will work up to the installation; however, once
636 installed, it will be unable to find libperl. Treat path handling
637 like in the other BSD dialects.
643 =head1 Internal Changes
645 XXX Changes which affect the interface available to C<XS> code go here.
646 Other significant internal changes for future core maintainers should
649 [ List each test improvement as a =item entry ]
653 =item * Fix harmless invalid read in Perl_re_compile() (f6d9469)
655 [perl #2460] described a case where electric fence reported an invalid
656 read. This could be reproduced under valgrind with blead and -e'/x/',
657 but only on a non-debugging build.
659 This was because it was checking for certain pairs of nodes (e.g. BOL + END)
660 and wasn't allowing for EXACT nodes, which have the string at the next
661 node position when using a naive NEXTOPER(first). In the non-debugging
662 build, the nodes aren't initialised to zero, and a 1-char EXACT node isn't
663 long enough to spill into the type field of the "next node".
665 Fix this by only using NEXTOPER(first) when we know the first node is
668 =item * Break out the generated function Perl_keywords() into F<keywords.c>, a new file. (26ea9e1)
670 As it and Perl_yylex() both need FEATURE_IS_ENABLED, feature_is_enabled() is
671 no longer static, and the two macro definitions move from toke.c to perl.h
673 Previously, one had to cut and paste the output of perl_keywords.pl into the
674 middle of toke.c, and it was not clear that it was generated code.
678 A lot of tests have been ported from Test to Test::More, e.g. in
687 =head1 Selected Bug Fixes
689 XXX Important bug fixes in the core language are summarised here.
690 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
691 L</Modules and Pragmata>.
693 [ List each fix as a =item entry ]
699 A Unicode C<\p{}> property match in a regular expression pattern will
700 now force Unicode rules for the rest of the regular expression
704 [perl #38456] binmode FH, ":crlf" only modifies top crlf layer (7826b36)
706 When pushed on top of the stack, crlf will no longer enable crlf layers
707 lower in the stack. This will prevent unexpected results.
711 Fix 'raw' layer for RT #80764 (ecfd064)
713 Made a ':raw' open do what it advertises to do (first open the file,
714 then binmode it), instead of leaving off the top layer.
718 Use PerlIOBase_open for pop, utf8 and bytes layers (c0888ac)
720 Three of Perl's builtin PerlIO layers (C<:pop>, C<:utf8> and
721 C<:bytes>) didn't allow stacking when opening a file. For example
724 open FH, '>:pop:perlio', 'some.file' or die $!;
726 Would throw an error: "Invalid argument". This has been fixed in this
731 An issue present since 5.13.1, where s/A/B/ with A utf8 and B
732 non-utf8, could cause corruption or segfaults has been
737 String evals will no longer fail after 2 billion scopes have been
738 compiled (d1bfb64, 2df5bdd, 0d311cd and 6012dc8)
742 [perl #81750] When strict 'refs' mode is off, C<%{...}> returns C<undef> if
743 its argument is undefined. An optimisation introduced in perl 5.12.0 to
744 make C<keys %{...}> faster when used as a boolean did not take this into
745 account, causing C<keys %{+undef}> (and C<keys %$foo> when C<$foo> is
746 undefined) to be an error, which it should only be in strict mode.
750 [perl #83194] Combining the vector (%v) flag and dynamic precision would
751 cause sprintf to confuse the order of its arguments, making it treat the
752 string as the precision and vice versa.
756 [perl #77692] Sometimes the UTF8 length cache would not be reset on a value
757 returned by substr, causing C<length(substr($uni_string,...))> to give
758 wrong answers. With C<${^UTF8CACHE}> set to -1, it would produce a 'panic'
763 During the restoration of a localised typeglob on scope exit, any
764 destructors called as a result would be able to see the typeglob in an
765 inconsistent state, containing freed entries, which could result in a
766 crash. This would affect code like this:
769 eval { die bless [] }; # puts an object in $@
774 Now the glob entries are cleared before any destructors are called. This
775 also means that destructors can vivify entries in the glob. So perl tries
776 again and, if the entries are re-created too many times, dies with a
777 'panic: gp_free...' error message.
781 [perl #78494] When pipes are shared between threads, the C<close> function
782 (and any implicit close, such as on thread exit) no longer blocks.
786 =head1 Known Problems
788 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
789 tests that had to be C<TODO>ed for the release would be noted here, unless
790 they were specific to a particular platform (see below).
792 This is a list of some significant unfixed bugs, which are regressions
793 from either 5.XXX.XXX or 5.XXX.XXX.
795 [ List each fix as a =item entry ]
807 XXX If any significant core contributor has died, we've added a short obituary
810 =head1 Acknowledgements
812 XXX The list of people to thank goes here.
814 =head1 Reporting Bugs
816 If you find what you think is a bug, you might check the articles
817 recently posted to the comp.lang.perl.misc newsgroup and the perl
818 bug database at http://rt.perl.org/perlbug/ . There may also be
819 information at http://www.perl.org/ , the Perl Home Page.
821 If you believe you have an unreported bug, please run the L<perlbug>
822 program included with your release. Be sure to trim your bug down
823 to a tiny but sufficient test case. Your bug report, along with the
824 output of C<perl -V>, will be sent off to perlbug@perl.org to be
825 analysed by the Perl porting team.
827 If the bug you are reporting has security implications, which make it
828 inappropriate to send to a publicly archived mailing list, then please send
829 it to perl5-security-report@perl.org. This points to a closed subscription
830 unarchived mailing list, which includes all the core committers, who be able
831 to help assess the impact of issues, figure out a resolution, and help
832 co-ordinate the release of patches to mitigate or fix the problem across all
833 platforms on which Perl is supported. Please only use this address for
834 security issues in the Perl core, not for modules independently
839 The F<Changes> file for an explanation of how to view exhaustive details
842 The F<INSTALL> file for how to build Perl.
844 The F<README> file for general stuff.
846 The F<Artistic> and F<Copying> files for copyright information.