=head1 NAME
-[ 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 v5.19.4
=head1 DESCRIPTION
If you are upgrading from an earlier release such as 5.19.2, first read
L<perl5193delta>, which describes differences between 5.19.2 and 5.19.3.
-=head1 Notice
+=head1 Core Enhancements
-XXX Any important notices here
+=head2 C<rand> now uses a consistent random number generator
-=head1 Core Enhancements
+Previously perl would use a platform specific random number generator, varying
+between the libc rand(), random() or drand48().
+
+This meant that the quality of perl's random numbers would vary from platform
+to platform, from the 15 bits of rand() on Windows to 48-bits on POSIX
+platforms such as Linux with drand48().
+
+Perl now uses its own internal drand48() implementation on all platforms. This
+does not make perl's C<rand> cryptographically secure. [perl #115928]
+
+=head2 Better 64-bit support
-XXX New core language features go here. Summarize user-visible core language
-enhancements. Particularly prominent performance optimisations could go
-here, but most should go in the L</Performance Enhancements> section.
+On 64-bit platforms, the internal array functions now use 64-bit offsets,
+allowing Perl arrays to hold more than 2**31 elements, if you have the memory
+available.
-[ List each enhancement as a =head2 entry ]
+The regular expression engine now supports strings longer than 2**31
+characters. [perl #112790, #116907]
-=head1 Security
+The functions PerlIO_get_bufsiz, PerlIO_get_cnt, PerlIO_set_cnt and
+PerlIO_set_ptrcnt now have SSize_t, rather than int, return values and
+parameters.
-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.
+=head2 New slice syntax
-[ List each security issue as a =head2 entry ]
+The new C<%hash{...}> and C<%array[...]> syntax returns a list of key/value (or
+index/value) pairs.
+
+=head2 EBCDIC support
+
+Core Perl now mostly works on EBCDIC platforms. This is not true of many
+modules, including some which are shipped with this release. If you have
+resources to help continue this process, including test machines, send email to
+L<mailto:perl-mvs@perl.org>.
+
+As a result of this, certain XS functions are now deprecated; see L</Internal
+Changes>.
=head1 Incompatible Changes
=head2 Locale decimal point character no longer leaks outside of
-S<C<use locale>> scope (with the exception of C<$!>)
+S<C<use locale>> scope (with the exception of $!)
This is actually a bug fix, but some code has come to rely on the bug being
present, so this change is listed here. The current locale that the program is
S<C<use locale>>. If your code is affected by this change, simply add a
S<C<use locale>>.
-Now, the only known place where C<'use locale'> is not respected is in the
+Now, the only known place where S<C<use locale>> is not respected is in the
stringification of L<$!|perlvar/$!>.
-=head1 Deprecations
-
-XXX Any deprecated features, syntax, modules etc. should be listed here.
-
-=head2 Module removals
+=head2 Assignments of Windows sockets error codes to $! now prefer F<errno.h> values over WSAGetLastError() values
+
+In previous versions of Perl, Windows sockets error codes as returned by
+WSAGetLastError() were assigned to $!, and some constants such as ECONNABORTED,
+not in F<errno.h> in VC++ (or the various Windows ports of gcc) were defined to
+corresponding WSAE* values to allow $! to be tested against the E* constants
+exported by L<Errno> and L<POSIX>.
+
+This worked well until VC++ 2010 and later, which introduced new E* constants
+with values E<gt> 100 into F<errno.h>, including some being (re)defined by perl
+to WSAE* values. That caused problems when linking XS code against other
+libraries which used the original definitions of F<errno.h> constants.
+
+To avoid this incompatibility, perl now maps WSAE* error codes to E* values
+where possible, and assigns those values to $!. The E* constants exported by
+L<Errno> and L<POSIX> are updated to match so that testing $! against them,
+wherever previously possible, will continue to work as expected, and all E*
+constants found in F<errno.h> are now exported from those modules with their
+original F<errno.h> values
+
+In order to avoid breakage in existing Perl code which assigns WSAE* values to
+$!, perl now intercepts the assignment and performs the same mapping to E*
+values as it uses internally when assigning to $! itself.
+
+However, one backwards-incompatibility remains: existing Perl code which
+compares $! against the numeric values of the WSAE* error codes that were
+previously assigned to $! will now be broken in those cases where a
+corresponding E* value has been assigned instead. This is only an issue for
+those E* values E<lt> 100, which were always exported from L<Errno> and
+L<POSIX> with their original F<errno.h> values, and therefore could not be used
+for WSAE* error code tests (e.g. WSAEINVAL is 10022, but the corresponding
+EINVAL is 22). (E* values E<gt> 100, if present, were redefined to WSAE*
+values anyway, so compatibility can be achieved by using the E* constants,
+which will work both before and after this change, albeit using different
+numeric values under the hood.)
-XXX Remove this section if inapplicable.
-
-The following modules will be removed from the core distribution in a
-future release, and will at that time need to be installed from CPAN.
-Distributions on CPAN which require these modules will need to list them as
-prerequisites.
-
-The core versions of these modules will now issue C<"deprecated">-category
-warnings to alert you to this fact. To silence these deprecation warnings,
-install the modules in question from CPAN.
-
-Note that these are (with rare exceptions) fine modules that you are encouraged
-to continue to use. Their disinclusion from core primarily hinges on their
-necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
-not usually on concerns over their design.
-
-=over
+=head1 Deprecations
-XXX Note that deprecated modules should be listed here even if they are listed
-as an updated module in the L</Modules and Pragmata> section.
+=head2 Literal control characters in variable names
-=back
+This deprecation affects things like $\cT, where \cT is a literal control in
+the source code. Surprisingly, it appears that originally this was intended as
+the canonical way of accessing variables like $^T, with the caret form only
+being added as an alternative.
-[ List each other deprecation as a =head2 entry ]
+The literal control form is being deprecated for two main reasons. It has what
+are likely unfixable bugs, such as $\cI not working as an alias for $^I, and
+their usage not being portable to non-ASCII platforms: While $^T will work
+everywhere, \cT is whitespace in EBCDIC. [perl #119123]
=head1 Performance Enhancements
=head1 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.
-
-[ Within each section, list entries as a =item entry ]
-
-=head2 New Modules and Pragmata
+=head2 Updated Modules and Pragmata
=over 4
=item *
-XXX
+L<autodie> has been upgraded from version 2.20 to 2.21.
-=back
-
-=head2 Updated Modules and Pragmata
-
-=over 4
+Numerous improvements have been made, many speed-related. See the F<Changes>
+file in the CPAN distribution for full details.
=item *
The fix for [perl #118525] introduced a regression in the behaviour of
C<B::CV::GV>, changing the return value from a C<B::SPECIAL> object on a
-C<NULL> C<CvGV> to C<undef>. C<B::CV::GV> again returns a C<B::SPECIAL>
-object in this case. [perl #119351]
+C<NULL> C<CvGV> to C<undef>. C<B::CV::GV> again returns a C<B::SPECIAL> object
+in this case. [perl #119351]
+
+L<B> version 1.44 (Perl 5.19.2) introduced four new B::OP methods, C<slabbed>,
+C<savefree>, C<static> and C<folded>, but these have never actually worked
+until now. They used to croak.
=item *
L<B::Concise> has been upgraded from version 0.98 to 0.99.
-The handling of the C<glob> operator, broken since Perl 5.17.6, has been fixed.
+The handling of the C<glob> operator, broken since Perl 5.17.6, has been fixed
+and handling of the new kvaslice and kvhslice operators have been added.
+
+=item *
+
+L<B::Deparse> has been upgraded from version 1.22 to 1.23.
+
+The new kvaslice and kvhslice operators have been added.
=item *
=item *
+C<Carp> also now shows subroutine arguments that are references to regexp
+objects in a consistent manner in stack traces.
+
+=item *
+
+C<Carp> now takes care not to clobber the status variables $! and $^E.
+
+=item *
+
C<Carp> now won't vivify the C<overload::StrVal> glob or subroutine or the
C<overload> stash.
=item *
C<Carp> now avoids some unwanted Unicode warnings on older Perls. This doesn't
-affect behaviour with current Perl.
+affect behaviour with current Perls.
=item *
=item *
+L<charnames> has been upgraded from version 1.38 to 1.39.
+
+This module now works on EBCDIC platforms.
+
+=item *
+
+L<CPAN> has been upgraded from version 2.00 to 2.03-TRIAL.
+
+Numerous updates and bug fixes are incorporated. See the F<Changes> file for
+full details.
+
+=item *
+
+L<CPAN::Meta> has been upgraded from version 2.132140 to 2.132620.
+
+META validation no longer allows a scalar value when a list was required for a
+field.
+
+=item *
+
L<CPAN::Meta::Requirements> has been upgraded from version 2.122 to 2.123.
No changes have been made to the installed code other than the version bump to
This upgrade is part of a larger change to make the array interface 64-bit safe
by using SSize_t instead of I32 for array indices.
+In addition, an EBCDIC fix has been applied.
+
=item *
L<Devel::Peek> has been upgraded from version 1.13 to 1.14.
This upgrade is part of a larger change to preserve referential identity when
passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
-nonexistent array elements.
+non-existent array elements.
+
+In addition, C<Dump> with no args was broken in Perl 5.19.3, but has now been
+fixed.
+
+=item *
+
+L<diagnostics> has been upgraded from version 1.32 to 1.33.
+
+C<=back> is now treated as the end of a warning description, thus keeping any
+trailing data in the file from showing up as part of the last warning's
+description. [perl #119817]
=item *
The documentation now makes it clear, as has always been the case, that
C<dl_unload_file> is only called automatically to unload all loaded shared
objects if the perl interpreter was built with the C macro
-DL_UNLOAD_ALL_AT_EXIT defined.
+DL_UNLOAD_ALL_AT_EXIT defined. Support for GNU DLD has also been removed.
=item *
-L<Encode> has been upgraded from version 2.52 to 2.54.
+L<Encode> has been upgraded from version 2.52 to 2.55.
An erroneous early return in C<decode_utf8> has been removed, and a bug in
-C<_utf8_on> under COW has been fixed.
+C<_utf8_on> under COW has been fixed. Encode also now uses L<parent> rather
+than L<base> throughout.
+
+=item *
+
+L<Errno> has been upgraded from version 1.19 to 1.20.
+
+The list of E* constants exported on Windows has been updated to reflect the
+changes made in the assignment of sockets error codes to $! (see
+L</Incompatible Changes>).
+
+=item *
+
+L<Exporter> has been upgraded from version 5.69 to 5.70.
+
+A number of typos have been corrected in the documentation.
+
+=item *
+
+L<ExtUtils::CBuilder> has been upgraded from version 0.280210 to 0.280212.
+
+No changes have been made to the installed code other than the version bump to
+keep in sync with the latest CPAN release.
=item *
-L<ExtUtils::MakeMaker> has been upgraded from version 6.72 to 6.74.
+L<ExtUtils::Command> has been upgraded from version 1.17 to 1.18.
+
+No changes have been made to the installed code other than the version bump to
+keep in sync with the latest CPAN release.
+
+=item *
+
+L<ExtUtils::MakeMaker> has been upgraded from version 6.72 to 6.76.
Numerous updates and bug fixes are incorporated. See the F<Changes> file for
full details.
=item *
-L<ExtUtils::ParseXS> has been upgraded from version 3.21 to 3.22.
+L<ExtUtils::ParseXS> has been upgraded from version 3.21 to 3.23.
+
+Unquoted "here-doc" markers for typemaps can now be optionally followed by a
+semicolon, just like quoted markers. [perl #119761]
+
+=item *
+
+L<File::Copy> has been upgraded from version 2.27 to 2.28.
-No changes have been made other than the version bump to keep in sync with the
-latest CPAN release.
+The documentation of C<copy> now makes it clear that trying to copy a file into
+a non-existent directory is not supported. [perl #119539]
+
+=item *
+
+L<File::Find> has been upgraded from version 1.24 to 1.25.
+
+Better diagnostics are now provided in the case of a failed C<chdir>.
=item *
L<File::Glob> has been upgraded from version 1.20 to 1.21.
-C<glob()> now warns in the context of C<use warnings "syscalls";> if the
-supplied pattern has an internal NUL (C<"\0">) character.
+C<glob> now warns in the context of C<use warnings "syscalls";> if the supplied
+pattern has an internal NUL (C<"\0">) character.
+
+=item *
+
+L<FileCache> has been upgraded from version 1.08 to 1.09.
+
+This upgrade is part of a larger change to use L<parent> rather than L<base>.
+
+=item *
+
+L<Hash::Util::FieldHash> has been upgraded from version 1.12 to 1.13.
+
+This upgrade is part of a larger change to use L<parent> rather than L<base>.
+
+=item *
+
+L<HTTP::Tiny> has been upgraded from version 0.034 to 0.035.
+
+Encoded data from C<post_form> now preserves term order if data is provided as
+an array reference. (They are still sorted for consistency if provided as a
+hash reference.)
+
+=item *
+
+L<I18N::LangTags> has been upgraded from version 0.39 to 0.40.
+
+Bosnian has now joined Croatian and Serbian in the lists of mutually
+intelligible Slavic languages. [perl #72594]
+
+=item *
+
+L<IO> has been upgraded from version 1.28 to 1.29.
+
+A minor internals-only change has been made to the XS code.
+
+=item *
+
+L<IO::Socket> has been upgraded from version 1.36 to 1.37.
+
+The C<connect> method has been updated in the light of changes made in the
+assignment of sockets error codes to $! on Windows (see L</Incompatible
+Changes>).
=item *
This upgrade is part of a larger change to preserve referential identity when
passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
-nonexistent array elements.
+non-existent array elements.
+
+=item *
+
+L<JSON::PP> has been patched from version 2.27202 to 2.27202_01.
+
+A precedence issue has been fixed in the return value of a private subroutine.
=item *
L<Math::BigInt> has been upgraded from version 1.9992 to 1.9993.
Cleaned up the L<Math::BigInt> and L<Math::BigFloat> documentation to be more
-consistent with other perl documentation. [perl #86686]
+consistent with other Perl documentation. [perl #86686]
-Added a bint() method for rounding towards zero. [perl #85296]
+Added a C<bint> method for rounding towards zero. [perl #85296]
=item *
=item *
-L<Module::CoreList> has been upgraded from version 2.97 to 2.98.
+L<Module::CoreList> has been upgraded from version 2.97 to 2.99.
The list of Perl versions covered has been updated.
+A function C<is_core> has been added, which returns true if the specified
+module was bundled with Perl. Optionally you can specify a minimum version of
+the module, and the specific version of Perl you're interested in (defaults to
+$^V, the running version of Perl).
+
=item *
L<Module::Load::Conditional> has been upgraded from version 0.54 to 0.58.
-C<requires> has been made more robust. [cpan #83728]
+C<requires> has been made more robust. [cpan #83728]
=item *
-L<Module::Metadata> has been upgraded from version 1.000014 to 1.000016.
+L<Module::Metadata> has been upgraded from version 1.000014 to 1.000018.
The module's DESCRIPTION has been re-worded regarding safety/security to
-satisfy CVE-2013-1437.
+satisfy CVE-2013-1437. Also, versions are now detainted if needed. [cpan
+#88576]
=item *
=item *
-L<parent> has been upgraded from version 0.226 to 0.227.
+L<Opcode> has been upgraded from version 1.25 to 1.26.
+
+The new kvaslice and kvhslice operators have been added.
+
+=item *
+
+L<parent> has been upgraded from version 0.226 to 0.228.
+
+No changes have been made to the installed code other than the version bump to
+keep in sync with the latest CPAN release.
+
+=item *
+
+L<Parse::CPAN::Meta> has been upgraded from version 1.4405 to 1.4407.
No changes have been made to the installed code other than the version bump to
keep in sync with the latest CPAN release.
=item *
-L<Perl::OSType> has been upgraded from version 1.003 to 1.004.
+L<Perl::OSType> has been upgraded from version 1.003 to 1.005.
The Unix OSType 'bitrig' has been added.
=item *
+L<perlfaq> has been upgraded from version 5.0150043 to 5.0150044.
+
+The use of C<gensym> in a number of examples has been removed, the use of C<&>
+in subroutine calls is now clarified and several new questions have been
+answered.
+
+=item *
+
+L<Pod::Html> has been upgraded from version 1.20 to 1.21.
+
+This upgrade is part of a larger change to use L<parent> rather than L<base>.
+
+=item *
+
+L<POSIX> has been upgraded from version 1.34 to 1.35.
+
+The list of E* constants exported on Windows has been updated to reflect the
+changes made in the assignment of sockets error codes to $! (see
+L</Incompatible Changes>).
+
+=item *
+
L<re> has been upgraded from version 0.25 to 0.26.
-A function signature has been corrected in the XS implementation.
+This upgrade is part of a larger change to support 64-bit string lengths in the
+regular expression engine.
=item *
L<Socket> has been upgraded from version 2.011 to 2.012.
-Syntax errors when building on the WinCE platform have been fixed. [cpan #87389]
+Syntax errors when building on the WinCE platform have been fixed. [cpan
+#87389]
=item *
This upgrade is part of a larger change to preserve referential identity when
passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
-nonexistent array elements.
+non-existent array elements.
+
+=item *
+
+L<Term::ReadLine> has been upgraded from version 1.13 to 1.14.
+
+Term::ReadLine::EditLine support has been added.
+
+=item *
+
+L<Test::Simple> has been patched from version 0.98 to 0.98_06.
+
+A precedence issue has been fixed in the return value of a private subroutine
+in L<Test::Builder>.
+
+=item *
+
+L<Time::Piece> has been upgraded from version 1.22 to 1.23.
+
+Day of year parsing (like "%y%j") has been fixed.
=item *
=item *
+L<Unicode::UCD> has been upgraded from version 0.53 to 0.54.
+
+This module now works on EBCDIC platforms.
+
+=item *
+
L<version> has been upgraded from version 0.9903 to 0.9904.
No changes have been made to the installed code other than the version bump to
The C<syscalls> warnings category has been added to check for embedded NUL
(C<"\0">) characters in pathnames and string arguments to other system calls.
+[perl #117265]
=item *
L<XS::Typemap> has been upgraded from version 0.10 to 0.11.
+This upgrade is part of the change to remove the uninitialized warnings
+exemption for uninitialized values returned by XSUBs (see the L</Selected Bug
+Fixes> section).
+
=back
-=head2 Removed Modules and Pragmata
+=head1 Documentation
+
+=head2 New Documentation
+
+=head3 L<perlrepository>
+
+This document was removed (actually, renamed L<perlgit> and given a major
+overhaul) in Perl 5.13.10, causing Perl documentation websites to show the now
+out of date version in Perl 5.12 as the latest version. It has now been
+restored in stub form, directing readers to current information.
+
+=head2 Changes to Existing Documentation
+
+=head3 L<perldata>
=over 4
=item *
-XXX
+New sections have been added to document the new index/value array slice and
+key/value hash slice syntax.
=back
-=head1 Documentation
+=head3 L<perldebguts>
-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>.
+=over 4
-=head2 New Documentation
+=item *
-XXX Changes which create B<new> files in F<pod/> go here.
+The C<&DB::goto> and C<&DB::lsub> debugger subroutines are now documented.
+[perl #77680]
-=head3 L<XXX>
+=back
-XXX Description of the purpose of the new file here
+=head3 L<perlguts>
-=head2 Changes to Existing Documentation
+=over 4
+
+=item *
-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.
+Numerous minor changes have been made to reflect changes made to the perl
+internals in this release.
-=head3 L<XXX>
+=back
+
+=head3 L<perlhack>
=over 4
=item *
-XXX Description of the change here
+The L<SUPER QUICK PATCH GUIDE|perlhack/SUPER QUICK PATCH GUIDE> section has
+been updated.
+
+=back
+
+=head3 L<perlsub>
+
+=over 4
+
+=item *
+
+A list of subroutine names used by the perl implementation is now included.
+[perl #77680]
=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.
-
=head2 New Diagnostics
-XXX Newly added diagnostic messages go under here, separated into New Errors
-and New Warnings
-
=head3 New Errors
=over 4
=item *
-XXX L<message|perldiag/"message">
+L<delete argument is indexE<sol>value array slice, use array slice|perldiag/"delete argument is index/value array slice, use array slice">
+
+(F) You used index/value array slice syntax (C<%array[...]>) as the argument to
+C<delete>. You probably meant C<@array[...]> with an @ symbol instead.
+
+=item *
+
+L<delete argument is keyE<sol>value hash slice, use hash slice|perldiag/"delete argument is key/value hash slice, use hash slice">
+
+(F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
+C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
=back
L<Invalid \0 character in %s for %s: %s\0%s|perldiag/"Invalid \0 character in %s for %s: %s\0%s">
(W syscalls) Embedded \0 characters in pathnames or other system call arguments
-produce a warning as of 5.20. The parts after the \0 were formerly ignored by
+produce a warning as of 5.20. The parts after the \0 were formerly ignored by
system calls.
+=item *
+
+L<Possible precedence issue with control flow operator|perldiag/"Possible precedence issue with control flow operator">
+
+(W syntax) There is a possible problem with the mixing of a control flow
+operator (e.g. C<return>) and a low-precedence operator like C<or>. Consider:
+
+ sub { return $a or $b; }
+
+This is parsed as:
+
+ sub { (return $a) or $b; }
+
+Which is effectively just:
+
+ sub { return $a; }
+
+Either use parentheses or the high-precedence variant of the operator.
+
+Note this may be also triggered for constructs like:
+
+ sub { 1 if die; }
+
+=item *
+
+L<Scalar value %%s[%s] better written as $%s[%s]|perldiag/"Scalar value %%s[%s] better written as $%s[%s]">
+
+(W syntax) In scalar context, you've used an array index/value slice (indicated
+by %) to select a single element of an array. Generally it's better to ask for
+a scalar value (indicated by $). The difference is that C<$foo[&bar]> always
+behaves like a scalar, both in the value it returns and when evaluating its
+argument, while C<%foo[&bar]> provides a list context to its subscript, which
+can do weird things if you're expecting only one subscript. When called in
+list context, it also returns the index (what C<&bar> returns) in addition to
+the value.
+
+=item *
+
+L<Scalar value %%s{%s} better written as $%s{%s}|perldiag/"Scalar value %%s{%s} better written as $%s{%s}">
+
+(W syntax) In scalar context, you've used a hash key/value slice (indicated by
+%) to select a single element of a hash. Generally it's better to ask for a
+scalar value (indicated by $). The difference is that C<$foo{&bar}> always
+behaves like a scalar, both in the value it returns and when evaluating its
+argument, while C<@foo{&bar}> and provides a list context to its subscript,
+which can do weird things if you're expecting only one subscript. When called
+in list context, it also returns the key in addition to the value.
+
+=item *
+
+L<Use of literal control characters in variable names is deprecated|perldiag/"Use of literal control characters in variable names is deprecated">
+
+(D deprecated) Using literal control characters in the source to refer to the
+^FOO variables, like $^X and ${^GLOBAL_PHASE} is now deprecated. This only
+affects code like $\cT, where \cT is a control in the source code: ${"\cT"} and
+$^T remain valid.
+
=back
=head2 Changes to Existing Diagnostics
-XXX Changes (i.e. rewording) of diagnostic messages go here
-
=over 4
=item *
-XXX Describe change here
+Warnings and errors from the regexp engine are now UTF-8 clean
-=back
+=item *
-=head1 Utility Changes
+The "Unknown switch condition" error message has some slight changes. This
+error triggers when there is an unknown condition in a C<(?(foo))> conditional.
+The error message used to read:
-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>.
+ Unknown switch condition (?(%s in regex;
-[ 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. ]
+But what %s could be was mostly up to luck. For C<(?(foobar))>, you might have
+seen "fo" or "f". For Unicode characters, you would generally get a corrupted
+string. The message has been changed to read:
+
+ Unknown switch condition (?(...)) in regex;
+
+Additionally, the C<'E<lt>-- HERE'> marker in the error will now point to the
+correct spot in the regex.
+
+=item *
+
+The "%s "\x%X" does not map to Unicode" warning is now correctly listed as a
+severe warning rather than as a fatal error.
+
+=back
+
+=head1 Utility Changes
=head3 L<find2perl>
=item *
-L<find2perl> now handles C<?> wildcards correctly. [perl #113054]
+L<find2perl> now handles C<?> wildcards correctly. [perl #113054]
=back
=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 *
=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 summarizing, although the bugs
-that they represent may be covered elsewhere.
-
-[ List each test improvement as a =item entry ]
-
=over 4
=item *
=item *
+A bug that was fixed in Perl 5.15.4 is now tested by the new test script
+F<t/io/eintr_print.t>. [perl #119097]
+
+=item *
+
+The new test scripts F<t/op/kvaslice.t> and F<t/op/kvhslice.t> test the new
+index/value array slice and key/value hash slice syntax respectively.
+
+=item *
+
Various cases of C<die>, C<last>, C<goto> and C<exit> triggering C<DESTROY> are
now tested by the new test script F<t/op/rt119311.t>.
=item *
-The new test script F<t/win32/signal.t> tests that C<$!> and C<$^E> are now
-preserved across signal handlers by the Win32 signal emulation code.
+The new test script F<t/op/waitpid.t> tests the fix for [perl #85228] (see
+L</Selected Bug Fixes>).
+
+=item *
+
+The latest copyright years in the top-level F<README> file and the B<perl -v>
+output are now tested as matching each other by the new test script
+F<t/porting/copyright.t>
+
+=item *
+
+The new test script F<t/win32/signal.t> tests that $! and $^E are now preserved
+across signal handlers by the Win32 signal emulation code.
=item *
=head1 Platform Support
-XXX Any changes to platform support should be listed in the sections below.
-
-[ Within the sections, list each platform as a =item entry with specific
-changes as paragraphs below it. ]
-
=head2 New Platforms
-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 FreeMiNT
+
+Support has been added for FreeMiNT, a free open-source OS for the Atari ST
+system and its successors, based on the original MiNT that was officially
+adopted by Atari.
+
=item Bitrig
-Compile support has been added for Bitrig, a fork of OpenBSD
+Compile support has been added for Bitrig, a fork of OpenBSD.
=back
=head2 Discontinued Platforms
-XXX List any platforms that this version of perl no longer compiles on.
+Configure hints and conditional code for several very old platforms has been
+removed. We have not received reports for these in many years, typically not
+since Perl 5.6.0.
=over 4
-=item XXX-some-platform
+=item AT&T 3b1
-XXX
+Configure support for the 3b1, also known as the AT&T Unix PC (and the similar
+AT&T 7300), has been removed.
=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 VMS
+
+The C<PERL_ENV_TABLES> feature to control the population of %ENV at perl
+start-up was broken in Perl 5.16.0 but has now been fixed.
+
+=item Win32
+
+C<rename> and C<link> on Win32 now set $! to ENOSPC and EDQUOT when
+appropriate. [perl #119857]
+
=item WinCE
-The building of XS modules has largely been restored. Several still cannot
+Perl now builds again on WinCE, following locale-related breakage (WinCE has
+non-existent locale support) introduced around 5.19.1. [perl #119443]
+
+The building of XS modules has largely been restored. Several still cannot
(yet) be built but it is now possible to build Perl on WinCE with only a couple
of further patches (to L<Socket> and L<ExtUtils::MakeMaker>), hopefully to be
incorporated soon.
+=item GNU/Hurd
+
+The BSD compatibility library C<libbsd> is no longer required for builds.
+
=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.
+=over 4
-[ List each change as a =item entry ]
+=item *
-=over 4
+The internal representation has changed for the match variables $1, $2 etc.,
+$`, $&, $', ${^PREMATCH}, ${^MATCH} and ${^POSTMATCH}. It uses slightly less
+memory, avoids string comparisons and numeric conversions during lookup, and
+uses 23 fewer lines of C. This change should not affect any external code.
=item *
-The internal representation has changed for the match variables C<$1>, C<$2>
-I<etc.>, C<$`>, C<$&>, C<$'>, C<${^PREMATCH}>, C<${^MATCH}> and
-C<${^POSTMATCH>. It uses slightly less memory, avoids string comparisons
-and numeric conversions during lookup, and uses 23 fewer lines of C. This
-change should not affect any external code.
+Arrays now use NULL internally to represent unused slots, instead of
+&PL_sv_undef. &PL_sv_undef is no longer treated as a special value, so
+av_store(av, 0, &PL_sv_undef) will cause element 0 of that array to hold a
+read-only undefined scalar. C<$array[0] = anything> will croak and
+C<\$array[0]> will compare equal to C<\undef>.
+
+=item *
+
+The SV returned by HeSVKEY_force() now correctly reflects the UTF8ness of the
+underlying hash key when that key is not stored as a SV. [perl #79074]
+
+=item *
+
+Certain rarely used functions and macros available to XS code are now, or are
+planned to be, deprecated. These are:
+C<utf8n_to_uvuni> (use C<utf8_to_uvchr_buf> instead),
+C<utf8_to_uni_buf> (use C<utf8_to_uvchr_buf> instead),
+C<valid_utf8_to_uvuni> (use C<utf8_to_uvchr_buf> instead),
+C<uvuni_to_utf8> (use C<uvchr_to_utf8> instead),
+C<NATIVE_TO_NEED> (this did not work properly anyway),
+and C<ASCII_TO_NEED> (this did not work properly anyway).
+
+Starting in this release, almost never does application code need to
+distinguish between the platform's character set and Latin1, on which the
+lowest 256 characters of Unicode are based.
=back
=head1 Selected Bug Fixes
-XXX Important bug fixes in the core language are summarized here. Bug fixes in
-files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
+=over 4
-[ List each fix as a =item entry ]
+=item *
-=over 4
+The value of $^E is now saved across signal handlers on Windows. [perl #85104]
=item *
-The value of C<$^E> is now saved across signal handlers on Win32. [perl #85104]
+A lexical filehandle (as in C<open my $fh...>) is usually given a name based on
+the current package and the name of the variable, e.g. "main::$fh". Under
+recursion, the filehandle was losing the "$fh" part of the name. This has been
+fixed.
-=back
+=item *
-=head1 Known Problems
+Perl 5.19.3 accidentally extended the previous bug to all closures, even when
+not called recursively, i.e. lexical handles in closure would always be called
+"main::" or "MyPackage::" etc. This has been fixed.
-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. Unfixed
-platform specific bugs also go here.
+=item *
-[ List each fix as a =item entry ]
+Uninitialized values returned by XSUBs are no longer exempt from uninitialized
+warnings. [perl #118693]
-=over 4
+=item *
+
+C<elsif ("")> no longer erroneously produces a warning about void context.
+[perl #118753]
=item *
-XXX
+Passing C<undef> to a subroutine now causes @_ to contain the same read-only
+undefined scalar that C<undef> returns. Furthermore, C<exists $_[0]> will now
+return true if C<undef> was the first argument. [perl #7508, #109726]
-=back
+=item *
+
+Passing a non-existent array element to a subroutine does not usually
+autovivify it unless the subroutine modifies its argument. This did not work
+correctly with negative indices and with non-existent elements within the
+array. The element would be vivified immediately. The delayed vivification
+has been extended to work with those. [perl #118691]
+
+=item *
+
+Assigning references or globs to the scalar returned by $#foo after the @foo
+array has been freed no longer causes assertion failures on debugging builds
+and memory leaks on regular builds.
+
+=item *
+
+Perl 5.19.2 threw line numbers off after some cases of line breaks following
+keywords, such as
+
+ 1 unless
+ 1;
+
+This has been fixed. [perl #118931]
+
+=item *
+
+On 64-bit platforms, large ranges like 1..1000000000000 no longer crash, but
+eat up all your memory instead. [perl #119161]
+
+=item *
+
+C<__DATA__> now puts the C<DATA> handle in the right package, even if the
+current package has been renamed through glob assignment.
+
+=item *
+
+The string position set by C<pos> could shift if the string changed
+representation internally to or from utf8. This could happen, e.g., with
+references to objects with string overloading.
+
+=item *
+
+Taking references to the return values of two C<pos> calls with the same
+argument, and then assigning a reference to one and C<undef> to the other,
+could result in assertion failures or memory leaks.
+
+=item *
+
+Elements of @- and @+ now update correctly when they refer to non-existent
+captures. Previously, a referenced element (C<$ref = \$-[1]>) could refer to
+the wrong match after subsequent matches.
+
+=item *
+
+When C<die>, C<last>, C<next>, C<redo>, C<goto> and C<exit> unwind the scope,
+it is possible for C<DESTROY> recursively to call a subroutine or format that
+is currently being exited. It that case, sometimes the lexical variables
+inside the sub would start out having values from the outer call, instead of
+being undefined as they should. This has been fixed. [perl #119311]
+
+=item *
+
+${^MPEN} is no longer treated as a synonym for ${^MATCH}.
+
+=item *
+
+Perl now tries a little harder to return the correct line number in
+C<(caller)[2]>. [perl #115768]
+
+=item *
+
+Line numbers inside multiline quote-like operators are now reported correctly.
+[perl #3643]
+
+=item *
+
+C<#line> directives inside code embedded in quote-like operators are now
+respected.
+
+=item *
+
+Line numbers are now correct inside the second here-doc when two here-doc
+markers occur on the same line.
+
+=item *
+
+Starting with Perl 5.12, line numbers were off by one if the B<-d> switch was
+used on the #! line. Now they are correct.
+
+=item *
+
+Perl 5.19.2 inadvertently stopped some lines of code from being available to
+the debugger if C<=E<gt>> occurred at the beginning of a line and the previous
+line ended with a keyword. This is now fixed.
+
+=item *
+
+Perl 5.19.2 allowed the PERL5DB environment variable to contain multiple lines
+of code, but those lines were not made available to the debugger. Now they are
+all stuffed into line number 0, accessible via C<$dbline[0]> in the debugger.
+
+=item *
+
+An optimization in Perl 5.18 made incorrect assumptions causing a bad
+interaction with the L<Devel::CallParser> CPAN module. If the module was
+loaded then lexical variables declared in separate statements following a
+C<my(...)> list might fail to be cleared on scope exit.
+
+=item *
+
+C<&xsub> and C<goto &xsub> calls now allow the called subroutine to autovivify
+elements of @_.
+
+=item *
-=head1 Obituary
+C<&xsub> and C<goto &xsub> no longer crash if *_ has been undefined and has no
+ARRAY entry (i.e. @_ does not exist).
-XXX If any significant core contributor has died, we've added a short obituary
-here.
+=item *
+
+C<&xsub> and C<goto &xsub> now work with tied @_.
+
+=item *
+
+Overlong identifiers no longer cause a buffer overflow (and a crash). They
+started doing so in Perl 5.18.
+
+=item *
+
+The warning "Scalar value @hash{foo} better written as $hash{foo}" now produces
+far fewer false positives. In particular, C<@hash{+function_returning_a_list}>
+and C<@hash{ qw "foo bar baz" }> no longer warn. The same applies to array
+slices. [perl #28380, #114024]
+
+=item *
+
+C<$! = EINVAL; waitpid(0, WNOHANG);> no longer goes into an internal infinite
+loop. [perl #85228]
+
+=item *
+
+Perl 5.19.3 accidentally caused C<\(1+2)> to return a reference to the same
+mutable scalar each time, so that modifications affect future evaluations.
+This has been fixed. [perl #119501]
+
+=item *
+
+A possible segmentation fault in filehandle duplication has been fixed.
+
+=item *
+
+A subroutine in @INC can return a reference to a scalar containing the initial
+contents of the file. However, that scalar was freed prematurely if not
+referenced elsewhere, giving random results.
+
+=back
=head1 Acknowledgements
https://perl5.git.perl.org / perl5.git / blobdiff