=head1 NAME
-perldelta - what is new for perl v5.13.5
+[ this is a template for a new perldelta file. Any text flagged as
+XXX needs to be processed before release. ]
+
+perldelta - what is new for perl v5.13.6
=head1 DESCRIPTION
-This document describes differences between the 5.13.4 release and
-the 5.13.5 release.
+This document describes differences between the 5.13.5 release and
+the 5.13.6 release.
+
+If you are upgrading from an earlier release such as 5.13.4, first read
+L<perl5135delta>, which describes differences between 5.13.4 and
+5.13.5.
+
+=head1 Notice
-If you are upgrading from an earlier release such as 5.13.3, first read
-L<perl5134delta>, which describes differences between 5.13.3 and
-5.13.4.
+XXX Any important notices here
=head1 Core Enhancements
-=head2 Adjacent pairs of nextstate opcodes are now optimized away
+XXX New core language features go here. Summarise user-visible core language
+enhancements. Particularly prominent performance optimisations could go
+here, but most should go in the L</Performance Enhancements> section.
+
+[ List each enhancement as a =head2 entry ]
+
+=head2 C<(?^...)> regex construct added to signify default modifiers
+
+A caret (also called a "cirumflex accent") C<"^"> immediately following
+a C<"(?"> in a regular expression now means that the subexpression is to
+not inherit the surrounding modifiers such as C</i>, but to revert to the
+Perl defaults. Any modifiers following the caret override the defaults.
+
+The stringification of regular expressions now uses this notation. The
+main purpose of this is to allow tests that rely on the stringification
+to not have to change when new modifiers are added. See
+L<perlre/Extended Patterns>.
+
+=head2 C<"d">, C<"l">, and C<"u"> regex modifiers added
+
+These modifiers are currently only available within a C<(?...)> construct.
+
+The C<"l"> modifier says to compile the regular expression as if it were
+in the scope of C<use locale>, even if it is not.
-Previously, in code such as
+The C<"u"> modifier currently does nothing.
- use constant DEBUG => 0;
+The C<"d"> modifier is used in the scope of C<use locale> to compile the
+regular expression as if it were not in that scope.
+See L<perlre/(?dlupimsx-imsx)>.
- sub GAK {
- warn if DEBUG;
- print "stuff\n";
- }
+=head2 C<\N{...}> now handles Unicode named character sequences
-the ops for C<warn if DEBUG;> would be folded to a C<null> op (C<ex-const>), but
-the C<nextstate> op would remain, resulting in a runtime op dispatch of
-C<nextstate>, C<nextstate>, ...
+Unicode has a number of named character sequences, in which particular sequences
+of code points are given names. C<\N{...}> now recognizes these.
+See L<charnames>.
-The execution of a sequence of C<nextstate> ops is indistinguishable from just
-the last C<nextstate> op so the peephole optimizer now eliminates the first of
-a pair of C<nextstate> ops, except where the first carries a label, since labels
-must not be eliminated by the optimizer and label usage isn't conclusively known
-at compile time.
+=head2 New function C<charnames::string_vianame()>
-=head2 API function to parse statements
+This function is a run-time version of C<\N{...}>, returning the string
+of characters whose Unicode name is its parameter. It can handle
+Unicode named character sequences, whereas the pre-existing
+C<charnames::vianame()> cannot, as the latter returns a single code
+point.
+See L<charnames>.
-The C<parse_fullstmt> function has been added to allow parsing of a single
-complete Perl statement. See L<perlapi> for details.
+=head2 Custom per-subroutine check hooks
-=head2 API functions for accessing the runtime hinthash
+XS code in an extension module can now annotate a subroutine (whether
+implemented in XS or in Perl) so that nominated XS code will be called
+at compile time (specifically as part of op checking) to change the op
+tree of that subroutine. The compile-time check function (supplied by
+the extension module) can implement argument processing that can't be
+expressed as a prototype, generate customised compile-time warnings,
+perform constant folding for a pure function, inline a subroutine
+consisting of sufficiently simple ops, replace the whole call with a
+custom op, and so on. This was previously all possible by hooking the
+C<entersub> op checker, but the new mechanism makes it easy to tie the
+hook to a specific subroutine. See L<perlapi/cv_set_call_checker>.
-A new C API for introspecting the hinthash C<%^H> at runtime has been added.
-See C<cop_hints_2hv>, C<cop_hints_fetchpvn>, C<cop_hints_fetchpvs>,
-C<cop_hints_fetchsv>, and C<hv_copy_hints_hv> in L<perlapi> for details.
+To help in writing custom check hooks, several subtasks within standard
+C<entersub> op checking have been separated out and exposed in the API.
-=head2 C interface to C<caller()>
+=head1 Security
-The C<caller_cx> function has been added as an XSUB-writer's equivalent of
-C<caller()>. See L<perlapi> for details.
+XXX Any security-related notices go here. In particular, any security
+vulnerabilities closed should be noted here rather than in the
+L</Selected Bug Fixes> section.
+
+[ List each security issue as a =head2 entry ]
=head1 Incompatible Changes
-=head2 Magic variables outside the main package
+=head2 Stringification of regexes has changed
-In previous versions of Perl, magic variables like C<$!>, C<%SIG>, etc. would
-'leak' into other packages. So C<%foo::SIG> could be used to access signals,
-C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
+Default regular expression modifiers are now notated by using
+C<(?^...)>. Code relying on the old stringification will fail. The
+purpose of this is so that when new modifiers are added, such code will
+not have to change (after this one time), as the stringification will
+automatically incorporate the new modifiers.
-This was a bug, or an 'unintentional' feature, which caused various ill effects,
-such as signal handlers being wiped when modules were loaded, etc.
+Code that needs to work properly with both old- and new-style regexes
+can avoid the whole issue by using (for Perls since 5.9.5):
-This has been fixed (or the feature has been removed, depending on how you see
-it).
+ use re qw(regexp_pattern);
+ my ($pat, $mods) = regexp_pattern($re_ref);
-=head2 Smart-matching against array slices
+where C<$re_ref> is a reference to a compiled regular expression. Upon
+return, C<$mods> will be a string containing all the non-default
+modifiers used when the regular expression was compiled, and C<$pattern>
+the actual pattern.
-Previously, the following code resulted in a successful match:
+If the actual stringification is important, or older Perls need to be
+supported, you can use something like the following:
- my @a = qw(a y0 z);
- my @b = qw(a x0 z);
- $a[0 .. $#b] ~~ @b;
+ # Accept both old and new-style stringification
+ my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? '^' : '-xism';
-This odd behaviour has now been fixed
-L<[perl #77468]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=77468>.
+And then use C<$modifiers> instead of C<-xism>.
-=head2 C API changes
+=head2 Regular expressions retain their localeness when interpolated
-The first argument of the C API function C<Perl_fetch_cop_label> has changed
-from C<struct refcounted he *> to C<COP *>, to better insulate the user from
-implementation details.
+Regular expressions compiled under C<"use locale"> now retain this when
+interpolated into a new regular expression compiled outside a
+C<"use locale">, and vice-versa.
-This API function was marked as "may change", and likely isn't in use outside
-the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other
-references to it.)
+Previously, a regular expression interpolated into another one inherited
+the localeness of the surrounding one, losing whatever state it
+originally had. This is considered a bug fix, but may trip up code that
+has come to rely on the incorrect behavior.
-=head1 Deprecations
+=head2 Directory handles not copied to threads
+
+On systems that do not have a C<fchdir> function, newly-created threads no
+longer inherit directory handles from their parent threads. Such programs
+would probably have crashed anyway
+L<[perl #75154]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=75154>.
+
+=head2 Negation treats strings differently from before
+
+The unary negation operator C<-> now treats strings that look like numbers
+as numbers
+L<[perl #57706]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=57706>.
-=head2 Use of qw(...) as parentheses
+=head2 Negative zero
-Historically the parser fooled itself into thinking that C<qw(...)> literals
-were always enclosed in parentheses, and as a result you could sometimes omit
-parentheses around them:
+Negative zero (-0.0), when converted to a string, now becomes "0" on all
+platforms. It used to become "-0" on some, but "0" on others.
- for $x qw(a b c) { ... }
+If you still need to determine whether a zero is negative, use
+C<sprintf("%g", $zero) =~ /^-/> or the L<Data::Float> module on CPAN.
-The parser no longer lies to itself in this way. Wrap the list literal in
-parentheses, like:
+=head1 Deprecations
+
+XXX Any deprecated features, syntax, modules etc. should be listed here.
+In particular, deprecated modules should be listed here even if they are
+listed as an updated module in the L</Modules and Pragmata> section.
- for $x (qw(a b c)) { ... }
+[ List each deprecation as a =head2 entry ]
=head1 Performance Enhancements
-=over 4
+XXX Changes which enhance performance without changing behaviour go here. There
+may well be none in a stable release.
-=item *
+[ List each enhancement as a =item entry ]
-Scalars containing regular expressions now only allocate the part of the C<SV>
-body they actually use, saving some space.
+=over 4
=item *
-Compiling regular expressions has been made faster for the case where upgrading
-the regex to utf8 is necessary but that isn't known when the compilation begins.
+XXX
=back
=head1 Modules and Pragmata
-=head2 Updated Modules and Pragmata
+XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
+go here. If Module::CoreList is updated, generate an initial draft of the
+following sections using F<Porting/corelist-perldelta.pl>, which prints stub
+entries to STDOUT. Results can be pasted in place of the '=head2' entries
+below. A paragraph summary for important changes should then be added by hand.
+In an ideal world, dual-life modules would have a F<Changes> file that could be
+cribbed.
-=over 4
+[ Within each section, list entries as a =item entry ]
-=item C<bignum>
+=head2 New Modules and Pragmata
-Upgraded from version 0.23 to 0.25.
+=over 4
-=item C<blib>
+=item *
-Upgraded from version 1.05 to 1.06.
+XXX
-=item C<open>
+=back
-Upgraded from version 1.07 to 1.08.
+=head2 Updated Modules and Pragmata
-=item C<threads-shared>
+=over 4
-Upgraded from version 1.33_02 to 1.33_03.
+=item *
-=item C<warnings> and C<warnings::register>
+C<Archive::Extract> has been upgraded from version 0.42 to 0.44
-Upgraded from version 1.10 to 1.11 and from version 1.01 to 1.02 respectively.
+=item *
-It is now possible to register warning categories other than the names of
-packages using C<warnings::register>. See L<perllexwarn> for more information.
+C<Carp> has been upgraded from version 1.18 to 1.19.
-=item C<B::Debug>
+It no longer autovivifies the C<*CORE::GLOBAL::caller> glob, something it
+started doing in 1.18, which was released with perl 5.13.4
+L<[perl #78082]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=78082>
-Upgraded from version 1.12 to 1.16.
+=item *
-=item C<CPANPLUS::Dist::Build>
+C<Data::Dumper> has been upgraded from version 2.128 to 2.129.
-Upgraded from version 0.46 to 0.48.
+C<Dumpxs> no longer crashes with globs returned by C<*$io_ref>
+L<[perl #72332]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72332>.
-=item C<Data::Dumper>
+=item *
-Upgraded from version 2.126 to 2.128.
+C<Digest::MD5> has been upgraded from version 2.40 to 2.51.
-This fixes a crash when using custom sort functions that might cause the stack
-to change.
+It is now safe to use this module in combination with threads.
-=item C<Encode>
+=item *
-Upgraded from version 2.39 to 2.40.
+C<File::DosGlob> has been upgraded from version 1.02 to 1.03.
-=item C<Errno>
+It allows patterns containing literal parentheses (they no longer need to
+be escaped). On Windows, it no longer adds an extra F<./> to the file names
+returned when the pattern is a relative glob with a drive specification,
+like F<c:*.pl>
+L<[perl #71712]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71712>.
-Upgraded from version 1.12 to 1.13.
+=item *
-On some platforms with unusual header files, like Win32/gcc using mingw64
-headers, some constants which weren't actually error numbers have been exposed
-by C<Errno>. This has been fixed
-L<[perl #77416]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=77416>.
+C<File::Find> has been upgraded from version 1.17 to 1.18.
-=item C<ExtUtils::MakeMaker>
+It improves handling of backslashes on Windows, so that paths such as
+F<c:\dir\/file> are no longer generated
+L<[perl #71710]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71710>.
-Upgraded from version 6.5601 to 6.57_05.
+=item *
-=item C<Filter::Simple>
+C<if> has been upgraded from version 0.05 to 0.06
-Upgraded from version 0.84 to 0.85.
+=item *
-=item C<Hash::Util>
+C<IPC::Open3> has been upgraded from version 1.06 to 1.07.
-Upgraded from version 0.08 to 0.09.
+The internal C<xclose> routine now knows how to handle file descriptors, as
+documented, so duplicating STDIN in a child process using its file
+descriptor now works
+L<[perl #76474]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71710>.
-=item C<Math::BigInt>
+=item *
-Upgraded from version 1.89_01 to 1.95.
+C<Locale::Maketext> has been upgraded from version 1.15 to 1.16.
-This fixes, among other things, incorrect results when computing binomial
-coefficients
-L<[perl #77640]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77640>.
+It fixes an infinite loop in C<Locale::Maketext::Guts::_compile()> when
+working with tainted values
+(L<CPAN RT #40727|https://rt.cpan.org/Public/Bug/Display.html?id=40727>).
-=item C<Math::BigInt::FastCalc>
+C<< ->maketext >> calls will now backup and restore C<$@> so that error
+messages are not supressed
+(L<CPAN RT #34182|https://rt.cpan.org/Public/Bug/Display.html?id=34182>).
-Upgraded from version 0.19 to 0.22.
+=item *
-=item C<Math::BigRat>
+C<Math::BigInt> has been upgraded from version 1.95 to 1.97.
-Upgraded from version 0.24 to 0.26.
+This prevents C<sqrt($int)> from crashing under C<use bigrat;>
+L<[perl #73534]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=73534>.
-=item C<Module::CoreList>
+=item *
-Upgraded from version 2.37 to 2.38.
+C<NEXT> has been upgraded from version 0.64 to 0.65.
-=item C<PerlIO::scalar>
+=item *
-Upgraded from version 0.08 to 0.09.
+C<overload> has been upgraded from version 1.10 to 1.11.
-=item C<POSIX>
+C<overload::Method> can now handle subroutines that are themselves blessed
+into overloaded classes
+L<[perl #71998]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71998>.
-Upgraded from version 1.19 to 1.20.
+=item *
-It now includes constants for POSIX signal constants.
+C<PathTools> has been upgraded from version 3.31_01 to 3.34.
-=item C<Safe>
+=item *
-Upgraded from version 2.27 to 2.28.
+C<sigtrap> has been upgraded from version 1.04 to 1.05.
-This fixes a possible infinite loop when looking for coderefs.
+It no longer tries to modify read-only arguments when generating a
+backtrace
+L<[perl #72340]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72340>.
-=item C<Test::Simple>
+=item *
-Upgraded from version 0.96 to 0.97_01.
+C<threads> has been upgraded from version 1.77_03 to 1.81
-=item C<Tie::Hash>
+=item *
-Upgraded from version 1.03 to 1.04.
+C<threads::shared> has been upgrade from version 1.33_03 to 1.34
-Calling C<< Tie::Hash-E<gt>TIEHASH() >> used to loop forever. Now it C<croak>s.
+=item *
-=item C<Unicode::Collate>
+C<Unicode::Collate> has been upgraded from version 0.59 to 0.62
-Upgraded from version 0.56 to 0.59.
+U::C::Locale newly supports locales: ar, de__phonebook, hu, hy, nso, om,
+tn, vi, hr, ig, sq, se to and uk
-=item C<XSLoader>
+=item *
-Upgraded from version 0.10 to 0.11.
+C<Unicode::Normalize> has been upgraded from version 1.06 to 1.07
=back
-=head1 Documentation
-
-=head2 Changes to Existing Documentation
-
-=head3 L<perlapi>
+=head2 Removed Modules and Pragmata
=over 4
=item *
-Many of the optree construction functions are now documented.
+XXX
=back
-=head3 L<perlbook>
+=head1 Documentation
-=over 4
+XXX Changes to files in F<pod/> go here. Consider grouping entries by
+file and be sure to link to the appropriate page, e.g. L<perlfunc>.
-=item *
+=head2 New Documentation
-Expanded to cover many more popular books.
+XXX Changes which create B<new> files in F<pod/> go here.
-=back
+=head3 L<XXX>
+
+XXX Description of the purpose of the new file here
-=head3 L<perlfaq>
+=head2 Changes to Existing Documentation
+
+XXX Changes which significantly change existing files in F<pod/> go here.
+However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
+section.
+
+=head3 L<XXX>
=over 4
=item *
-L<perlfaq>, L<perlfaq2>, L<perlfaq4>, L<perlfaq5>, L<perlfaq6>, L<perlfaq8>, and
-L<perlfaq9> have seen various updates and modernizations.
+The documentation for the C<SvTRUE> macro was simply wrong in stating that
+get-magic is not processed. It has been corrected.
=back
including warnings and fatal error messages. For the complete list of
diagnostic messages, see L<perldiag>.
+XXX New or changed warnings emitted by the core's C<C> code go here. Also
+include any changes in L<perldiag> that reconcile it to the C<C> code.
+
+[ Within each section, list entries as a =item entry ]
+
=head2 New Diagnostics
+XXX Newly added diagnostic messages go here
+
=over 4
=item *
-Parsing code internal error (%s)
+XXX
+
+=back
+
+=head2 Changes to Existing Diagnostics
+
+XXX Changes (i.e. rewording) of diagnostic messages go here
-New fatal error produced when parsing code supplied by an extension violated the
-parser's API in a detectable way.
+=over 4
=item *
-Use of qw(...) as parentheses is deprecated
+The 'Layer does not match this perl' error message has been replaced with
+these more helpful messages:
+
+=over 4
+
+=item *
-See L</"Use of qw(...) as parentheses"> for details.
+PerlIO layer function table size (%d) does not match size expected by this
+perl (%d)
+
+=item *
+
+PerlIO layer instance size (%d) does not match size expected by this perl
+(%d)
+
+=back
+
+L<[perl #73754]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=73754>
=back
=head1 Utility Changes
-=head3 L<h2ph>
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
+here. Most of these are built within the directories F<utils> and F<x2p>.
+
+[ List utility changes as a =head3 entry for each utility and =item
+entries for each change
+Use L<XXX> with program names to get proper documentation linking. ]
+
+=head3 L<XXX>
=over 4
=item *
-The use of a deprecated C<goto> construct has been removed
-L<[perl #74404]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=74404>.
+XXX
=back
-=head1 Testing
+=head1 Configuration and Compilation
+
+XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
+go here. Any other changes to the Perl build process should be listed here.
+However, any platform-specific changes should be listed in the
+L</Platform Support> section, instead.
+
+[ List changes as a =item entry ].
=over 4
=item *
-The new F<t/lib/universal.t> script tests the Internal::* functions and other
-things in F<universal.c>.
+XXX
-=item *
+=back
+
+=head1 Testing
+
+XXX Any significant changes to the testing of a freshly built perl should be
+listed here. Changes which create B<new> files in F<t/> go here as do any
+large changes to the testing harness (e.g. when parallel testing was added).
+Changes to existing files in F<t/> aren't worth summarising, although the bugs
+that they represent may be covered elsewhere.
-A rare race condition in F<t/op/while_readdir.t> has been fixed, stopping it
-from failing randomly when running tests in parallel.
+[ List each test improvement as a =item entry ]
+
+=over 4
=item *
-The new F<t/op/leaky-magic.t> script tests that magic applied to variables in
-the main packages does not affect other packages.
+The script F<t/op/threads-dirh.t> has been added, which tests interaction
+of threads and directory handles.
=back
=head1 Platform Support
-=head2 Platform-Specific Notes
+XXX Any changes to platform support should be listed in the sections below.
-=over 4
+[ Within the sections, list each platform as a =item entry with specific
+changes as paragraphs below it. ]
+
+=head2 New Platforms
-=item VMS
+XXX List any platforms that this version of perl compiles on, that previous
+versions did not. These will either be enabled by new files in the F<hints/>
+directories, or new subdirectories and F<README> files at the top level of the
+source tree.
=over 4
-=item *
+=item XXX-some-platform
+
+XXX
+
+=back
+
+=head2 Discontinued Platforms
-Make C<PerlIOUnix_open> honour default permissions on VMS.
+XXX List any platforms that this version of perl no longer compiles on.
-When C<perlio> became the default and C<unixio> became the default bottom layer,
-the most common path for creating files from Perl became C<PerlIOUnix_open>,
-which has always explicitly used C<0666> as the permission mask.
+=over 4
-To avoid this, C<0777> is now passed as the permissions to C<open()>. In the
-VMS CRTL, C<0777> has a special meaning over and above intersecting with the
-current umask; specifically, it allows Unix syscalls to preserve native default
-permissions.
+=item XXX-some-platform
+
+XXX
=back
+=head2 Platform-Specific Notes
+
+XXX List any changes for specific platforms. This could include configuration
+and compilation changes or changes in portability/compatibility. However,
+changes within modules for platforms should generally be listed in the
+L</Modules and Pragmata> section.
+
+=over 4
+
+=item IRIX
+
+Conversion of strings to floating-point numbers is now more accurate on
+IRIX systems
+L<[perl #32380]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=32380>.
+
+=item Mac OS X
+
+Early versions of Mac OS X (Darwin) had buggy implementations of the
+C<setregid>, C<setreuid>, C<setrgid> and C<setruid> functions, so perl
+would pretend they did not exist.
+
+These functions are now recognised on Mac OS 10.5 (Leopard; Darwin 9) and
+higher, as they have been fixed
+L<[perl #72990]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72990>.
+
+=item OpenVOS
+
+perl now builds again with OpenVOS (formerly known as Stratus VOS)
+L<[perl #78132]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=78132>.
+
+=item Windows
+
+C<$Config{gccversion}> is now set correctly when perl is built using the
+mingw64 compiler from L<http://mingw64.org>
+L<[perl #73754]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=73754>.
+
+The build process proceeds more smoothly with mingw and dmake when
+F<C:\MSYS\bin> is in the PATH, due to a C<Cwd> fix.
+
=back
=head1 Internal Changes
+XXX Changes which affect the interface available to C<XS> code go here.
+Other significant internal changes for future core maintainers should
+be noted as well.
+
+[ List each test improvement as a =item entry ]
+
=over 4
=item *
-C<CALL_FPTR> and C<CPERLscope> have been deprecated.
+See L</Regular expressions retain their localeness when interpolated>,
+above.
+
+=item *
+
+The C<sv_cmp_flags>, C<sv_cmp_locale_flags>, C<sv_eq_flags> and
+C<sv_collxfrm_flags> functions have been added. These are like their
+non-_flags counterparts, but allow one to specify whether get-magic is
+processed.
-Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
-which was removed in Perl 5.8. Nowadays these macros do exactly nothing, so
-they shouldn't be used anymore.
+The C<sv_cmp>, C<sv_cmp_locale>, C<sv_eq> and C<sv_collxfrm> functions have
+been replaced with wrappers around the new functions.
-For compatibility, they are still defined for external C<XS> code. Only
-extensions defining C<PERL_CORE> must be updated now.
+=item *
+
+A new C<sv_2bool_flags> function has been added.
+
+This is like C<sv_2bool>, but it lets the calling code decide whether
+get-magic is handled. C<sv_2bool> is now a macro that calls the new
+function.
+
+=item *
+
+A new macro, C<SvTRUE_nomg>, has been added.
+
+This is like C<SvTRUE>, except that it does not process magic. It uses the
+new C<sv_2bool_flags> function.
+
+=item *
+
+C<sv_catsv_flags> no longer calls C<mg_get> on its second argument (the
+source string) if the flags passed to it do not include SV_GMAGIC. So it
+now matches what the documentation says it does.
=item *
-C<lex_stuff_pvs()> has been added as a convenience macro wrapping
-C<lex_stuff_pvn()> for literal strings.
+A new interface has been added for custom check hooks on subroutines. See
+L/Custom per-subroutine check hooks>, above.
=item *
-The recursive part of the peephole optimizer is now hookable.
+List op building functions have been added to the
+API. See L<op_append_elem|perlapi/op_append_elem>,
+L<op_append_list|perlapi/op_append_list>, and
+L<op_prepend_elem|perlapi/op_prepend_elem>.
-In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
-C<PL_rpeepp> is now available to hook into the optimizer recursing into
-side-chains of the optree.
+=item *
+
+The L<LINKLIST|perlapi/LINKLIST> macro, part of op building that
+constructs the execution-order op chain, has been added to the API.
=back
=head1 Selected Bug Fixes
+XXX Important bug fixes in the core language are summarised here.
+Bug fixes in files in F<ext/> and F<lib/> are best summarised in
+L</Modules and Pragmata>.
+
+[ List each fix as a =item entry ]
+
=over 4
=item *
-A regression introduced in Perl 5.12.0, making
-C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
-fixed. C<$x> will now be C<undef>.
+A regular expression match in the right-hand side of a global substitution
+(C<s///g>) that is in the same scope will no longer cause match variables
+to have the wrong values on subsequent iterations. This can happen when an
+array or hash subscript is interpolated in the right-hand side, as in
+C<s|(.)|@a{ print($1), /./ }|g>
+L<[perl #19078]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=19078>.
=item *
-A fatal error in regular expressions when processing UTF-8 data has been fixed
-L<[perl #75680]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=75680>.
+Constant-folding used to cause
+
+ $text =~ ( 1 ? /phoo/ : /bear/)
+
+to turn into
+
+ $text =~ /phoo/
+
+at compile time. Now it correctly matches against C<$_>
+L<[perl #20444]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=20444>.
=item *
-An erroneous regular expression engine optimization that caused regex verbs like
-C<*COMMIT> to sometimes be ignored has been removed.
+Parsing Perl code (either with string C<eval> or by loading modules) from
+within a C<UNITCHECK> block no longer causes the interpreter to crash
+L<[perl #70614]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=70614>.
=item *
-The Perl debugger now also works in taint mode
-L<[perl #76872]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=76872>.
+When C<-d> is used on the shebang (C<#!>) line, the debugger now has access
+to the lines of the main program. In the past, this sometimes worked and
+sometimes did not, depending on what order things happened to be arranged
+in memory
+L<[perl #71806]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71806>.
=item *
-Several memory leaks in cloning and freeing threaded Perl interpreters have been
-fixed L<[perl #77352]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77352>.
+The C<y///> or C<tr///> operator now calls get-magic (e.g., the C<FETCH>
+method of a tie) on its left-hand side just once, not twice
+L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>.
=item *
-A possible string corruption when doing regular expression matches on overloaded
-objects has been fixed
-L<[perl #77084]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77084>.
+String comparison (C<eq>, C<ne>, C<lt>, C<gt>, C<le>, C<ge> and
+C<cmp>) and logical not (C<not> and C<!>) operators no longer call magic
+(e.g., tie methods) twice on their operands
+L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>.
+
+This bug was introduced in an earlier 5.13 release, and does not affect
+perl 5.12.
=item *
-Magic applied to variables in the main package no longer affects other packages.
-See L</Magic variables outside the main package> above
-L<[perl #76138]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=76138>.
+When a tied (or other magic) variable is used as, or in, a regular
+expression, it no longer has its C<FETCH> method called twice
+L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>.
+
+This bug was introduced in an earlier 5.13 release, and does not affect
+perl 5.12.
=item *
-Opening a glob reference via C<< open $fh, "E<gt>", \*glob >> will no longer
-cause the glob to be corrupted when the filehandle is printed to. This would
-cause perl to crash whenever the glob's contents were accessed
-L<[perl #77492]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77492>.
+The C<-C> command line option can now be followed by other options
+L<[perl #72434]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72434>.
=item *
-The postincrement and postdecrement operators, C<++> and C<-->, used to cause
-leaks when being used on references. This has now been fixed.
+Assigning a glob to a PVLV used to convert it to a plain string. Now it
+works correctly, and a PVLV can hold a glob. This would happen when a
+nonexistent hash or array element was passed to a subroutine:
+
+ sub { $_[0] = *foo }->($hash{key});
+ # $_[0] would have been the string "*main::foo"
+
+It also happened when a glob was assigned to, or returned from, an element
+of a tied array or hash
+L<[perl #36051]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=36051>.
=item *
-A bug when replacing the glob of a loop variable within the loop has been fixed
-L<[perl #21469]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=21469>. This
-means the following code will no longer crash:
+Creating a new thread when directory handles were open used to cause a
+crash, because the handles were not cloned, but simply passed to the new
+thread, resulting in a double free.
- for $x (...) {
- *x = *y;
- }
+Now directory handles are properly, on systems that have a C<fchdir>
+function. On other systems, new threads simply do not inherit directory
+handles from their parent threads
+L<[perl #75154]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=75154>.
=item *
-Perl would segfault if the undocumented C<Internals> functions that used
-reference prototypes were called with the C<&foo()> syntax, e.g.
-C<&Internals::SvREADONLY(undef)>
-L<[perl #77776]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77776>.
+The regular expression parser no longer hangs when parsing C<\18> and
+C<\88>.
+
+This bug was introduced in version 5.13.5 and did not affect earlier
+versions
+L<[perl #78058]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78058>.
+
+=item *
-These functions now call C<SvROK> on their arguments before dereferencing them
-with C<SvRV>, and we test for this case in F<t/lib/universal.t>.
+Subroutine redefinition works once more in the debugger
+L<[perl #48332]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=48332>.
=item *
-When assigning a list with duplicated keys to a hash, the assignment used to
-return garbage and/or freed values:
+The C<&> C<|> C<^> bitwise operators no longer coerce read-only arguments
+L<[perl #20661]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=20661>.
- @a = %h = (list with some duplicate keys);
+=item *
-This has now been fixed
-L<[perl #31865]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=31865>.
+Stringifying a scalar containing -0.0 no longer has the affect of turning
+false into true
+L<[perl #45133]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=45133>.
=item *
-An earlier release of the 5.13 series of Perl changed the semantics of opening a
-reference to a copy of a glob:
+Aliasing packages by assigning to globs or deleting packages by deleting
+their containing stash elements used to have erratic effects on method
+resolution, because the internal 'isa' caches were not reset. This has been
+fixed.
+
+=back
+
+=head1 Known Problems
+
+XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
+tests that had to be C<TODO>ed for the release would be noted here, unless
+they were specific to a particular platform (see below).
- my $var = *STDOUT;
- open my $fh, '>', \$var;
+This is a list of some significant unfixed bugs, which are regressions
+from either 5.XXX.XXX or 5.XXX.XXX.
-This was a mistake, and the previous behaviour from Perl 5.10 and 5.12, which is
-to treat \$var as a scalar reference, has now been restored.
+[ List each fix as a =item entry ]
+
+=over 4
=item *
-The regular expression bracketed character class C<[\8\9]> was effectively the
-same as C<[89\000]>, incorrectly matching a NULL character. It also gave
-incorrect warnings that the C<8> and C<9> were ignored. Now C<[\8\9]> is the
-same as C<[89]> and gives legitimate warnings that C<\8> and C<\9> are
-unrecognized escape sequences, passed-through.
+XXX
+
+=back
+
+=head1 Obituary
+
+XXX If any significant core contributor has died, we've added a short obituary
+here.
+
+=head1 Errata
+
+=over 4
=item *
-C<warn()> now respects utf8-encoded scalars
-L<[perl #45549]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=45549>.
+Fixed a typo in L<perl5135delta> regarding array slices and smart matching
=back
If the bug you are reporting has security implications, which make it
inappropriate to send to a publicly archived mailing list, then please send
-it to perl5-security-report@perl.org. This points to a closed subscription
+it to perl5-security-report@perl.org. This points to a closed subscription
unarchived mailing list, which includes all the core committers, who be able
to help assess the impact of issues, figure out a resolution, and help
co-ordinate the release of patches to mitigate or fix the problem across all
-platforms on which Perl is supported. Please only use this address for
+platforms on which Perl is supported. Please only use this address for
security issues in the Perl core, not for modules independently
distributed on CPAN.
https://perl5.git.perl.org / perl5.git / blobdiff