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 synyom 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<Version::Requirements> version 0.101020 has been added as a dual-life
174 module. It provides a standard library to model and manipulates module
175 prerequisites and version constraints as defined in the L<CPAN::Meta::Spec>.
179 =head2 Updated Modules and Pragmata
185 C<Carp> has been upgraded from version 1.19 to 1.20.
187 [perl #82854] It now avoids using regular expressions that cause perl to
188 load its Unicode tables, in order to avoid the 'BEGIN not safe after
189 errors' error that will ensue if there has been a syntax error.
193 C<CGI> has been upgraded from version 3.51 to 3.52
197 C<CPANPLUS> has been upgraded from version 0.9011 to 0.9101
199 Includes support for META.json and MYMETA.json and a change to
200 using Digest::SHA for CPAN checksums.
204 C<diagnostics> has been upgraded from version 1.21 to 1.22.
206 It now renders pod links slightly better, and has been taught to find
207 descriptions for messages that share their descriptions with other
212 C<IO::Select> has been upgraded from version 1.17 to 1.18.
214 It now allows IO::Handle objects (and objects in derived classes) to be
215 removed from an IO::Select set even if the underlying file descriptor is
220 C<IPC::Cmd> has been upgraded from version 0.68 to 0.70
224 C<HTTP::Tiny> has been upgraded from version 0.009 to 0.010
228 C<Math::BigInt> has been upgraded from version 1.99_04 to 1.991.
232 C<Module::Build> has been upgraded from version 0.3607 to 0.3622.
234 A notable change is the deprecation of several modules.
235 Module::Build::Version has been deprecated and Module::Build now relies
236 directly upon L<version>. Module::Build::ModuleInfo has been deprecated in
237 favor of a standalone copy of it called L<Module::Metadata>.
238 Module::Build::YAML has been deprecated in favor of L<CPAN::Meta::YAML>.
242 C<Module::Load::Conditional> has been upgraded from version 0.40 to 0.44
246 C<Module::Metadata> has been upgraded from version 1.000003 to 1.000004.
250 C<overload> has been upgraded from version 1.12 to 1.13.
252 The documentation has greatly improved. See L</Documentation> below.
256 C<Parse::CPAN::Meta> has been upgraded from version 1.40 to 1.4401.
258 The latest Parse::CPAN::Meta can now read YAML or JSON files using
259 L<CPAN::Meta::YAML> and L<JSON::PP>, which are now part of the Perl core.
263 C<re> has been upgraded from version 0.16 to 0.17.
265 It now supports the double-a flag: C<use re '/aa';>
269 C<Term::UI> has been upgraded from version 0.24 to 0.26
273 C<Unicode::Collate> has been upgraded from version 0.68 to 0.72
275 This also sees the switch from using the pure-perl version of this
276 module to the XS version.`
280 C<VMS::DCLsym> has been upgraded from version 1.04 to 1.05.
282 Two bugs have been fixed [perl #84086]:
284 The symbol table name was lost when tying a hash, due to a thinko in
285 C<TIEHASH>. The result was that all tied hashes interacted with the
288 Unless a symbol table name had been explicitly specified in the call
289 to the constructor, querying the special key ':LOCAL' failed to
290 identify objects connected to the local symbol table.
294 Added new function C<Unicode::UCD::num()>. This function will return the
295 numeric value of the string passed it; C<undef> if the string in its
296 entirety has no safe numeric value.
298 To be safe, a string must be a single character which has a numeric
299 value, or consist entirely of characters that match \d, coming from the
300 same Unicode block of digits. Thus, a mix of Bengali and Western
301 digits would be considered unsafe, as well as a mix of half- and
302 full-width digits, but strings consisting entirely of Devanagari digits
303 or of "Mathematical Bold" digits would would be safe.
307 C<CPAN> has been upgraded from version1.94_63 to 1.94_64.
315 =head2 Removed Modules and Pragmata
327 XXX Changes to files in F<pod/> go here. Consider grouping entries by
328 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
330 =head2 New Documentation
332 XXX Changes which create B<new> files in F<pod/> go here.
336 XXX Description of the purpose of the new file here
338 =head2 Changes to Existing Documentation
340 XXX Changes which significantly change existing files in F<pod/> go here.
341 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
350 L<overload>'s documentation has practically undergone a rewrite. It
351 is now much more straightforward and clear.
355 =head3 L<perlhack> and perlrepository
361 The L<perlhack> and perlrepository documents have been heavily edited and
362 split up into several new documents.
364 The L<perlhack> document is now much shorter, and focuses on the Perl 5
365 development process and submitting patches to Perl. The technical content has
366 been moved to several new documents, L<perlsource>, L<perlinterp>,
367 L<perlhacktut>, and L<perlhacktips>. This technical content has only been
370 The perlrepository document has been renamed to L<perlgit>. This new document
371 is just a how-to on using git with the Perl source code. Any other content
372 that used to be in perlrepository has been moved to perlhack.
382 The documentation for the C<map> function now contains more examples,
383 see B<perldoc -f map> (f947627)
393 Examples in L<perlfaq4> have been updated to show the use of
394 L<Time::Piece>. (9243591)
404 Many POD related RT bugs and other issues which are too numerous to
405 enumerate have been solved by Michael Stevens.
411 The following additions or changes have been made to diagnostic output,
412 including warnings and fatal error messages. For the complete list of
413 diagnostic messages, see L<perldiag>.
415 XXX New or changed warnings emitted by the core's C<C> code go here. Also
416 include any changes in L<perldiag> that reconcile it to the C<C> code.
418 [ Within each section, list entries as a =item entry ]
420 =head2 New Diagnostics
422 XXX Newly added diagnostic messages go here
426 =item "\b{" is deprecated; use "\b\{" instead
428 =item "\B{" is deprecated; use "\B\{" instead
430 Use of an unescaped "{" immediately following a C<\b> or C<\B> is now
431 deprecated so as to reserve its use for Perl itself in a future release.
433 =item regcomp: Add warning if \p is used under locale. (fb2e24c)
435 C<\p> implies Unicode matching rules, which are likely going to be
436 different than the locale's.
438 =item panic: gp_free failed to free glob pointer - something is repeatedly re-creating entries
440 This new error is triggered if a destructor called on an object in a
441 typeglob that is being freed creates a new typeglob entry containing an
442 object with a destructor that creates a new entry containing an object....
446 =head2 Changes to Existing Diagnostics
448 XXX Changes (i.e. rewording) of diagnostic messages go here
454 The warning message about regex unrecognized escapes passed through is
455 changed to include any literal '{' following the 2-char escape. e.g.,
456 "\q{" will include the { in the message as part of the escape
459 =item * C<binmode $fh, ':scalar'> no longer warns (8250589)
461 Perl will now no longer produce this warning:
463 $ perl -we 'open my $f, ">", \my $x; binmode $f, "scalar"'
464 Use of uninitialized value in binmode at -e line 1.
472 =head1 Utility Changes
474 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
475 here. Most of these are built within the directories F<utils> and F<x2p>.
477 [ List utility changes as a =head3 entry for each utility and =item
478 entries for each change
479 Use L<XXX> with program names to get proper documentation linking. ]
491 =head1 Configuration and Compilation
493 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
494 go here. Any other changes to the Perl build process should be listed here.
495 However, any platform-specific changes should be listed in the
496 L</Platform Support> section, instead.
498 [ List changes as a =item entry ].
502 =item * make reg_eval_scope.t TODOs consistently fail (daaf7ac)
504 Some of the TODO tests in reg_eval_scope.t spuriously passed under
505 non-threaded builds. Make the tests harder so they always fail.
507 Since one of the key bugs in (?{..}) is the trashing of the parent pad,
508 add some extra lexical vars to the parent scope and check they're still
513 Stop EU::CBuilder's tests from failing in parallel (cbf59d5)
515 It used to use the same paths for temporary files in all tests. This
516 blew up randomly when the tests were run in parallel.
526 XXX Any significant changes to the testing of a freshly built perl should be
527 listed here. Changes which create B<new> files in F<t/> go here as do any
528 large changes to the testing harness (e.g. when parallel testing was added).
529 Changes to existing files in F<t/> aren't worth summarising, although the bugs
530 that they represent may be covered elsewhere.
532 [ List each test improvement as a =item entry ]
538 F<porting/FindExt.t> now skips all tests on a static (-Uusedl) build
543 F<porting/FindExt.t> now passes on non-Win32 platforms when some
544 extensions are built statically.
548 =head1 Platform Support
550 XXX Any changes to platform support should be listed in the sections below.
552 [ Within the sections, list each platform as a =item entry with specific
553 changes as paragraphs below it. ]
557 XXX List any platforms that this version of perl compiles on, that previous
558 versions did not. These will either be enabled by new files in the F<hints/>
559 directories, or new subdirectories and F<README> files at the top level of the
564 =item XXX-some-platform
570 =head2 Discontinued Platforms
572 XXX List any platforms that this version of perl no longer compiles on.
576 =item XXX-some-platform
582 =head2 Platform-Specific Notes
584 XXX List any changes for specific platforms. This could include configuration
585 and compilation changes or changes in portability/compatibility. However,
586 changes within modules for platforms should generally be listed in the
587 L</Modules and Pragmata> section.
597 The C<test-prep> build target now depends on F<pod/perltoc.pod> to allow the
598 F<t/porting/buildtoc.t> test to run successfully.
608 [perl #82988] Skip hanging taint.t test on MirBSD 10 (1fb83d0)
610 Skip a hanging test under MirBSD that was already being skipped under
615 Previously if you build perl with a shared libperl.so on MirBSD (the
616 default config), it will work up to the installation; however, once
617 installed, it will be unable to find libperl. Treat path handling
618 like in the other BSD dialects.
624 =head1 Internal Changes
626 XXX Changes which affect the interface available to C<XS> code go here.
627 Other significant internal changes for future core maintainers should
630 [ List each test improvement as a =item entry ]
634 =item * Fix harmless invalid read in Perl_re_compile() (f6d9469)
636 [perl #2460] described a case where electric fence reported an invalid
637 read. This could be reproduced under valgrind with blead and -e'/x/',
638 but only on a non-debugging build.
640 This was because it was checking for certain pairs of nodes (e.g. BOL + END)
641 and wasn't allowing for EXACT nodes, which have the string at the next
642 node position when using a naive NEXTOPER(first). In the non-debugging
643 build, the nodes aren't initialised to zero, and a 1-char EXACT node isn't
644 long enough to spill into the type field of the "next node".
646 Fix this by only using NEXTOPER(first) when we know the first node is
649 =item * Break out the generated function Perl_keywords() into F<keywords.c>, a new file. (26ea9e1)
651 As it and Perl_yylex() both need FEATURE_IS_ENABLED, feature_is_enabled() is
652 no longer static, and the two macro definitions move from toke.c to perl.h
654 Previously, one had to cut and paste the output of perl_keywords.pl into the
655 middle of toke.c, and it was not clear that it was generated code.
659 A lot of tests have been ported from Test to Test::More, e.g. in
668 =head1 Selected Bug Fixes
670 XXX Important bug fixes in the core language are summarised here.
671 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
672 L</Modules and Pragmata>.
674 [ List each fix as a =item entry ]
680 A Unicode C<\p{}> property match in a regular expression pattern will
681 now force Unicode rules for the rest of the regular expression
685 [perl #38456] binmode FH, ":crlf" only modifies top crlf layer (7826b36)
687 When pushed on top of the stack, crlf will no longer enable crlf layers
688 lower in the stack. This will prevent unexpected results.
692 Fix 'raw' layer for RT #80764 (ecfd064)
694 Made a ':raw' open do what it advertises to do (first open the file,
695 then binmode it), instead of leaving off the top layer.
699 Use PerlIOBase_open for pop, utf8 and bytes layers (c0888ac)
701 Three of Perl's builtin PerlIO layers (C<:pop>, C<:utf8> and
702 C<:bytes>) didn't allow stacking when opening a file. For example
705 open FH, '>:pop:perlio', 'some.file' or die $!;
707 Would throw an error: "Invalid argument". This has been fixed in this
712 An issue present since 5.13.1, where s/A/B/ with A utf8 and B
713 non-utf8, could cause corruption or segfaults has been
718 String evals will no longer fail after 2 billion scopes have been
719 compiled (d1bfb64, 2df5bdd, 0d311cd and 6012dc8)
723 [perl #81750] When strict 'refs' mode is off, C<%{...}> returns C<undef> if
724 its argument is undefined. An optimisation introduced in perl 5.12.0 to
725 make C<keys %{...}> faster when used as a boolean did not take this into
726 account, causing C<keys %{+undef}> (and C<keys %$foo> when C<$foo> is
727 undefined) to be an error, which it should only be in strict mode.
731 [perl #83194] Combining the vector (%v) flag and dynamic precision would
732 cause sprintf to confuse the order of its arguments, making it treat the
733 string as the precision and vice versa.
737 [perl #77692] Sometimes the UTF8 length cache would not be reset on a value
738 returned by substr, causing C<length(substr($uni_string,...))> to give
739 wrong answers. With C<${^UTF8CACHE}> set to -1, it would produce a 'panic'
744 During the restoration of a localised typeglob on scope exit, any
745 destructors called as a result would be able to see the typeglob in an
746 inconsistent state, containing freed entries, which could result in a
747 crash. This would affect code like this:
750 eval { die bless [] }; # puts an object in $@
755 Now the glob entries are cleared before any destructors are called. This
756 also means that destructors can vivify entries in the glob. So perl tries
757 again and, if the entries are re-created too many times, dies with a
758 'panic: gp_free...' error message.
762 [perl #78494] When pipes are shared between threads, the C<close> function
763 (and any implicit close, such as on thread exit) no longer blocks.
767 =head1 Known Problems
769 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
770 tests that had to be C<TODO>ed for the release would be noted here, unless
771 they were specific to a particular platform (see below).
773 This is a list of some significant unfixed bugs, which are regressions
774 from either 5.XXX.XXX or 5.XXX.XXX.
776 [ List each fix as a =item entry ]
788 XXX If any significant core contributor has died, we've added a short obituary
791 =head1 Acknowledgements
793 XXX The list of people to thank goes here.
795 =head1 Reporting Bugs
797 If you find what you think is a bug, you might check the articles
798 recently posted to the comp.lang.perl.misc newsgroup and the perl
799 bug database at http://rt.perl.org/perlbug/ . There may also be
800 information at http://www.perl.org/ , the Perl Home Page.
802 If you believe you have an unreported bug, please run the L<perlbug>
803 program included with your release. Be sure to trim your bug down
804 to a tiny but sufficient test case. Your bug report, along with the
805 output of C<perl -V>, will be sent off to perlbug@perl.org to be
806 analysed by the Perl porting team.
808 If the bug you are reporting has security implications, which make it
809 inappropriate to send to a publicly archived mailing list, then please send
810 it to perl5-security-report@perl.org. This points to a closed subscription
811 unarchived mailing list, which includes all the core committers, who be able
812 to help assess the impact of issues, figure out a resolution, and help
813 co-ordinate the release of patches to mitigate or fix the problem across all
814 platforms on which Perl is supported. Please only use this address for
815 security issues in the Perl core, not for modules independently
820 The F<Changes> file for an explanation of how to view exhaustive details
823 The F<INSTALL> file for how to build Perl.
825 The F<README> file for general stuff.
827 The F<Artistic> and F<Copying> files for copyright information.