[ 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 v5.21.1
+perldelta - what is new for perl v5.21.3
=head1 DESCRIPTION
-This document describes differences between the 5.21.0 release and the 5.21.1
+This document describes differences between the 5.21.2 release and the 5.21.3
release.
-If you are upgrading from an earlier release such as 5.20.0, first read
-L<perl5210delta>, which describes differences between 5.20.0 and 5.21.0.
+If you are upgrading from an earlier release such as 5.21.1, first read
+L<perl5212delta>, which describes differences between 5.21.1 and 5.21.2.
=head1 Notice
=head1 Core Enhancements
-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.
+=head2 C<defined(@array = LIST)> is no longer fatal
-[ List each enhancement as a =head2 entry ]
-
-=head2 C<qr/foo/x> now ignores any Unicode pattern white space
-
-The C</x> regular expression modifier allows the pattern to contain
-white space and comments, both of which are ignored, for improved
-readability. Until now, not all the white space characters that Unicode
-designates for this purpose were handled. The additional ones now
-recognized are
-U+0085 NEXT LINE,
-U+200E LEFT-TO-RIGHT MARK,
-U+200F RIGHT-TO-LEFT MARK,
-U+2028 LINE SEPARATOR,
-and
-U+2029 PARAGRAPH SEPARATOR.
-
-=head2 S<C<use locale>> can restrict which locale categories are affected
-
-It is now possible to pass a parameter to S<C<use locale>> to specify
-a subset of locale categories to be locale-aware, with the remaining
-ones unaffected. See L<perllocale/The "use locale" pragma> for details.
+In 5.21.1, C<defined(@array)> was made fatal. This has been relaxed
+to not die if the argument is assigning to an array.
=head1 Security
-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 The L<Safe> module could allow outside packages to be replaced
-[ List each security issue as a =head2 entry ]
+Critical bugfix: outside packages could be replaced. L<Safe> has
+been patched to 2.38 to address this.
=head1 Incompatible Changes
-XXX For a release on a stable branch, this section aspires to be:
-
- There are no changes intentionally incompatible with 5.XXX.XXX
- If any exist, they are bugs, and we request that you submit a
- report. See L</Reporting Bugs> below.
-
-=head2 In double-quotish C<\cI<X>>, I<X> must now be a printable ASCII character
-
-In prior releases, failure to do this raised a deprecation warning.
-
-=head2 Splitting the tokens C<(?> and C<(*> in regular expressions is
-now a fatal compilation error.
-
-These had been deprecated since v5.18.
-
-=head2 5 additional characters are treated as white space under C</x> in
-regex patterns (unless escaped)
-
-The use of these characters with C</x> outside bracketed character
-classes and when not preceeded by a backslash has raised a deprecation
-warning since v5.18. Now they will be ignored. See L</qrE<sol>fooE<sol>x>
-for the list of the five characters.
-
-=head2 Comment lines within S<C<(?[ ])>> now are ended only by a C<\n>
-
-S<C<(?[ ])>> is an experimental feature, introduced in v5.18. It operates
-as if C</x> is always enabled. But there was a difference, comment
-lines (following a C<#> character) were terminated by anything matching
-C<\R> which includes all vertical whitespace, such as form feeds. For
-consistency, this is now changed to match what terminates comment lines
-outside S<C<(?[ ])>>, namely a C<\n> (even if escaped), which is the
-same as what terminates a heredoc string and formats.
-
-=head2 Omitting % and @ on hash and array names is no longer permitted
-
-Really old Perl let you omit the @ on array names and the % on hash
-names in some spots. This has issued a deprecation warning since Perl
-5.0, and is no longer permitted.
-
-=head2 C<"$!"> text is now in English outside C<"use locale"> scope
-
-Previously, the text, unlike almost everything else, always came out
-based on the current underlying locale of the program. (Also affected
-on some systems is C<"$^E>".) For programs that are unprepared to
-handle locale, this can cause garbage text to be displayed. It's better
-to display text that is translatable via some tool than garbage text
-which is much harder to figure out.
-
-=head2 C<"$!"> text will be returned in UTF-8 when appropriate
-
-The stringification of C<$!> and C<$^E> will have the UTF-8 flag set
-when the text is actually non-ASCII UTF-8. This will enable programs
-that are set up to be locale-aware to properly output messages in the
-user's native language. Code that needs to continue the 5.20 and
-earlier behavior can do the stringification within the scopes of both
-'use bytes' and 'use locale ":messages". No other Perl operations will
-be affected by locale; only C<$!> and C<$^E> stringification. The
-'bytes' pragma causes the UTF-8 flag to not be set, just as in previous
-Perl releases. This resolves [perl #112208].
-
-=head1 Deprecations
-
-XXX Any deprecated features, syntax, modules etc. should be listed here.
-
-=head2 Using a NO-BREAK space in a character alias for C<\N{...}> is now
-deprecated
-
-This non-graphic character is essentially indistinguishable from a
-regular space, and so should not be allowed. See
-L<charnames/CUSTOM ALIASES>.
-
-=head2 Module removals
-
-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
-
-=item XXX
-
-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.
-
-=back
-
-[ List each other deprecation as a =head2 entry ]
-
-=head1 Performance Enhancements
+=head2 S<C<use UNIVERSAL '...'>> is now a fatal error
-XXX Changes which enhance performance without changing behaviour go here.
-There may well be none in a stable release.
-
-[ List each enhancement as a =item entry ]
-
-=over 4
-
-=item *
-
-Many internal functions have been refactored to improve performance and reduce
-their memory footprints.
-
-L<[perl #121436]|https://rt.perl.org/Ticket/Display.html?id=121436>
-L<[perl #121906]|https://rt.perl.org/Ticket/Display.html?id=121906>
-L<[perl #121969]|https://rt.perl.org/Ticket/Display.html?id=121969>
-
-=item *
-
-C<-T> and C<-B> filetests will return sooner when an empty file is detected.
-
-L<perl #121489|https://rt.perl.org/Ticket/Display.html?id=121489>
-
-=back
+Importing functions from C<UNIVERSAL> has been deprecated since v5.12, and
+is now a fatal error. S<C<"use UNIVERSAL">> without any arguments is still
+allowed.
=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>. 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
-
-=over 4
-
-=item *
-
-XXX
-
-=back
-
=head2 Updated Modules and Pragmata
=over 4
=item *
-L<Carp> has been upgraded from version 1.3301 to 1.34.
-
-Carp::Heavy now ignores version mismatches with Carp if Carp is newer
-than 1.12, since Carp::Heavy's guts were merged into Carp at that
-point.
-L<[perl #121574]|https://rt.perl.org/Ticket/Display.html?id=121574>
+L<B::Debug> has been upgraded from version 1.19 to 1.21
=item *
-L<Encode> has been upgraded from version 2.60_01 to 2.62.
-
-B<piconv> now has better error handling when the encoding name is nonexistent,
-and a build breakage when upgrading L<Encode> in perl-5.8.2 and earlier has
-been fixed.
+L<Config::Perl::V> has been upgraded from version 0.20 to 0.22.
=item *
-The libnet collection of modules has been upgraded from version 1.25 to 1.27.
-
-There are only whitespace changes to the installed files.
+L<CPAN::Meta> has been upgraded from version 2.141520 to 2.142060.
=item *
-The Locale-Codes collection of modules has been upgraded from vesion 3.30 to 3.31.
-
-Fixed a bug in the scripts used to extract data from spreadsheets that
-prevented the SHP currency code from being found.
-L<[cpan #94229]|https://rt.cpan.org/Ticket/Display.html?id=94229>
+L<CPAN::Meta::Requirements> has been upgraded from version 2.125 to 2.126.
=item *
-L<Math::BigInt> has been upgraded from version 1.9993 to 1.9994.
+L<ExtUtils::Manifest> has been upgraded from version 1.64 to 1.65.
-Synchronize POD changes from the CPAN release.
+The MANIFEST is now opened with C<:raw>, to prevent C<CRLF>s leaking in.
-C<< Math::BigFloat->blog(x) >> would sometimes return blog(2*x) when
-the accuracy was greater than 70 digits.
+=item *
-The result of C<< Math::BigFloat->bdiv() >> in list context now
-satisfies C<< x = quotient * divisor + remainder >>.
+L<HTTP::Tiny> has been upgraded from version 0.043 to 0.047.
=item *
-L<Math::BigRat> has been upgraded from version 0.2606 to 0.2607.
+L<perl5db.pl> has been upgraded from version 1.45 to 1.46.
-Synchronize POD changes from the CPAN release.
+Fixed the scope level handling of the debugger's C<y> command.
=item *
-L<Module::Metadata> has been upgraded from version 1.000022 to 1.000024.
+L<POSIX> has been upgraded from version 1.41 to 1.42.
-Support installations on older perls with an L<ExtUtils::MakeMaker> earlier
-than 6.63_03
+Replaced the thread-unsafe code used to prevent duplicate warning
+messages for using the isxxx() functions. [perl #122476]
=item *
-L<perl5db.pl> has been upgraded from version 1.44 to 1.45.
-
-=item *
+L<Safe> has been upgraded from version 2.37 to 2.38.
-A mismatch between the documentation and the code in utf8::downgrade()
-was fixed in favour of the documentation. The optional second argument
-is now correctly treated as a perl boolean (true/false semantics) and
-not as an integer.
+Critical bugfix: outside packages could be replaced.
=item *
-fork() in the debugger under C<tmux> will now create a new window for
-the forked process. L<[perl
-#121333]|https://rt.perl.org/Ticket/Display.html?id=121333>
+L<Socket> has been upgraded from version 2.014 to 2.015.
-The debugger now saves the current working directory on startup and
-restores it when you restart your program with C<R> or <rerun>. L<[perl
-#121509]|https://rt.perl.org/Ticket/Display.html?id=121509>
+Test suite updates, particularly useful for Solaris and cygwin, and
+a slight change to the pattern used for IPv4 address matching.
-L<Unicode::Collate> has been upgraded from version 1.04 to 1.07.
+=back
-Version 0.67's improved discontiguous contractions is invalidated by default
-and is supported as a parameter 'long_contraction'.
+=head1 Documentation
-=item *
+=head2 Changes to Existing Documentation
-L<Unicode::Normalize> has been upgraded from version 1.17 to 1.18.
+=head3 L<perlexperiment>
-The XSUB implementation has been removed in favour of pure Perl.
+=over 4
=item *
-L<Hash::Util> has been upgraded from version 0.16 to 0.17.
-
-Minor bug fixes and documentation fixes to Hash::Util::hash_stats()
-
+Added reference to L<feature>.
=back
-=head2 Removed Modules and Pragmata
+=head3 L<perlguts>
=over 4
=item *
-XXX
+Details on C level symbols and libperl.t added.
=back
-=head1 Documentation
-
-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>.
-
-=head2 New Documentation
-
-XXX Changes which create B<new> files in F<pod/> go here.
-
-=head3 L<XXX>
+=head3 L<perlhacktips>
-XXX Description of the purpose of the new file here
+=over 4
-=head2 Changes to Existing Documentation
+=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.
+Recommended replacements for tmpfile, atoi, strtol, and strtoul added.
+
+=back
-=head3 L<perlfunc>
+=head3 L<perlop>
=over 4
=item *
-C<-l> now notes that it will return false if symlinks aren't supported by the
-file system.
-
-L<[perl #121523]|https://rt.perl.org/Ticket/Display.html?id=121523>
+ASCII v. EBCDIC clarifications added.
=back
-=head3 L<perlapi>
+=head3 L<perlsec>
=over 4
=item *
-C<sv_usepvn_flags> - Fix documentation to mention the use of C<NewX> instead of
-C<malloc>.
-
-L<[perl #121869]|https://rt.perl.org/Ticket/Display.html?id=121869>
+Comments added on algorithmic complexity and tied hashes.
=back
-=head3 L<perlhacktips>
+=head3 L<perlvms>
=over 4
=item *
-Updated documentation for the C<test.valgrind> C<make> target.
-
-L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
+Updated documentation on environment and shell interaction in VMS.
=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<Hexadecimal float: internal error|perldiag/"Hexadecimal float: internal error">
+
+(F) Something went horribly bad in hexadecimal float handling.
+
+=item *
+
+L<Hexadecimal float: unsupported long double format|perldiag/"Hexadecimal float: unsupported long double format">
+
+(F) You have configured Perl to use long doubles but
+the internals of the long double format are unknown,
+therefore the hexadecimal float output is impossible.
=back
=item *
-L<PerlIO layer ':win32' is experimental|perldiag/"PerlIO layer ':win32' is experimental">:
-
-(S experimental::win32_perlio) The C<:win32> PerlIO layer is
-experimental. If you want to take the risk of using this layer,
-simply disable this warning:
+L<Hexadecimal float: exponent overflow|perldiag/"Hexadecimal float: exponent overflow">
- no warnings "experimental::win32_perlio";
+(W overflow) The hexadecimal floating point has larger exponent
+than the floating point supports.
-=back
-
-=head2 Changes to Existing Diagnostics
+=item *
-XXX Changes (i.e. rewording) of diagnostic messages go here
+L<Hexadecimal float: exponent underflow|perldiag/"Hexadecimal float: exponent underflow">
-=over 4
+(W overflow) The hexadecimal floating point has smaller exponent
+than the floating point supports.
=item *
-L<Unsuccessful %s on filename containing newline|perldiag/"Unsuccessful %s on filename containing newline">
+L<Hexadecimal float: mantissa overflow|perldiag/"Hexadecimal float: mantissa overflow">
-This warning is now only produced when the newline is at the end of
-the filename.
+(W overflow) The hexadecimal floating point literal had more bits in
+the mantissa (the part between the 0x and the exponent, also known as
+the fraction or the significand) than the floating point supports.
-=back
+=item *
-=head1 Utility Changes
+L<Hexadecimal float: precision loss|perldiag/"Hexadecimal float: precision loss">
-XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
-Most of these are built within the directory F<utils>.
+(W overflow) The hexadecimal floating point had internally more
+digits than could be output. This can be caused by unsupported
+long double formats, or by 64-bit integers not being available
+(needed to retrieve the digits under some configurations).
-[ List utility changes as a =head2 entry for each utility and =item
-entries for each change
-Use L<XXX> with program names to get proper documentation linking. ]
+=back
-=head2 F<x2p/>
+=head2 Changes to Existing Diagnostics
=over 4
=item *
-The F<x2p/> directory has been removed from the Perl core.
-
-This removes find2perl, s2p and a2p. They have all been released to CPAN as
-separate distributions (App::find2perl, App::s2p, App::a2p).
+L<require> with no argument or undef used to warn about a Null filename; now
+it dies with C<Missing or undefined argument to require>.
=back
=item *
-C<make test.valgrind> now supports parallel testing.
-
-For example:
+Internal handling of floating point values has been improved.
- TEST_JOBS=9 make test.valgrind
-
-See L<perlhacktips/valgrind> for more information.
+=item *
-L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
+MurmurHash64A and MurmurHash64B can now be configured as the internal hash
+function.
=back
=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 XXX-some-platform
-
-XXX
-
-=back
-
-=head2 Discontinued Platforms
-
-XXX List any platforms that this version of perl no longer compiles on.
+=head2 Platform-Specific Notes
=over 4
-=item NeXTSTEP/OPENSTEP
+=item Android
-NeXTSTEP was proprietary OS bundled with NeXT's workstations in the early
-to mid 90's; OPENSTEP was an API specification that provided a NeXTSTEP-like
-environment on a non-NeXTSTEP system. Both are now long dead, so support
-for building Perl on them has been removed.
+Build support has been improved for cross-compiling in general and for
+Android in particular.
-=back
+=item Solaris
-=head2 Platform-Specific Notes
+C<c99> options have been cleaned up, hints look for C<solstudio>
+as well as C<SUNWspro>, and support for native C<setenv> has been added.
-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.
+=item VMS
-=over 4
+C<finite>, C<finitel>, and C<isfinite> detection has been added to
+C<configure.com>, environment handling has had some minor changes, and
+a fix for legacy feature checking status.
-=item XXX-some-platform
+=item Windows
-XXX
+C<%I64d> is now being used instead of C<%lld> for MinGW.
=back
significant internal changes for future core maintainers should be noted as
well.
+[ List each change as a =item entry ]
+
=over 4
=item *
-The deprecated variable C<PL_sv_objcount> has been removed.
+Added L<perlapi/sync_locale>.
+Changing the program's locale should be avoided by XS code. Nevertheless,
+certain non-Perl libraries called from XS, such as C<Gtk> do so. When this
+happens, Perl needs to be told that the locale has changed. Use this function
+to do so, before returning to Perl.
=item *
-Perl now tries to keep the locale category C<LC_NUMERIC> set to "C"
-except around operations that need it to be set to the program's
-underlying locale. This protects the many XS modules that cannot cope
-with the decimal radix character not being a dot. Prior to this
-release, Perl initialized this category to "C", but a call to
-C<POSIX::setlocale()> would change it. Now such a call will change the
-underlying locale of the C<LC_NUMERIC> category for the program, but the
-locale exposed to XS code will remain "C". There is an API under
-development for those relatively few modules that need to use the
-underlying locale. This API will be nailed down during the course of
-developing v5.21. Send email to L<mailto:perl5-porters@perl.org> for
-guidance.
+Added L<perlapi/grok_atou> as a safer replacement for atoi and strtol.
=back
=item *
-index() and rindex() no longer crash when used on strings over 2GB in
-size.
-L<[perl #121562]|https://rt.perl.org/Ticket/Display.html?id=121562>.
-
-=item *
-
-A small previously intentional memory leak in PERL_SYS_INIT/PERL_SYS_INIT3 on
-Win32 builds was fixed. This might affect embedders who repeatedly create and
-destroy perl engines within the same process.
+Failing to compile C<use Foo> in an eval could leave a spurious
+C<BEGIN> subroutine definition, which would produce a "Subroutine
+BEGIN redefined" warning on the next use of C<use>, or other C<BEGIN>
+block. [perl #122107]
=item *
-C<POSIX::localeconv()> now returns the data for the program's underlying
-locale even when called from outside the scope of S<C<use locale>>.
+C<method { BLOCK } ARGS> syntax now correctly parses the arguments if they
+begin with an opening brace. [perl #46947]
=item *
-C<POSIX::localeconv()> now works properly on platforms which don't have
-C<LC_NUMERIC> and/or C<LC_MONETARY>, or for which Perl has been compiled
-to disregard either or both of these locale categories. In such
-circumstances, there are now no entries for the corresponding values in
-the hash returned by C<localeconv()>.
+External libraries and Perl may have different ideas of what the locale is.
+This is problematic when parsing version strings if the locale's numeric
+separator has been changed. Version parsing has been patched to ensure
+it handles the locales correctly. [perl #121930]
=item *
-C<POSIX::localeconv()> now marks appropriately the values it returns as
-UTF-8 or not. Previously they were always returned as a bytes, even if
-they were supposed to be encoded as UTF-8.
-
-=item *
-
-On Microsoft Windows, within the scope of C<S<use locale>>, the following
-POSIX character classes gave results for many locales that did not
-conform to the POSIX standard:
-C<[[:alnum:]]>,
-C<[[:alpha:]]>,
-C<[[:blank:]]>,
-C<[[:digit:]]>,
-C<[[:graph:]]>,
-C<[[:lower:]]>,
-C<[[:print:]]>,
-C<[[:punct:]]>,
-C<[[:upper:]]>,
-C<[[:word:]]>,
-and
-C<[[:xdigit:]]>.
-These are because the underlying Microsoft implementation does not
-follow the standard. Perl now takes special precautions to correct for
-this.
-
-=item *
-
-Many issues have been detected by L<Coverity|http://www.coverity.com/> and
-fixed.
+A bug has been fixed where zero-length assertions and code blocks inside of a
+regex could cause L<pos> to see an incorrect value. [perl #122460]
=back
=back
-=head1 Obituary
-
-XXX If any significant core contributor has died, we've added a short obituary
-here.
-
=head1 Acknowledgements
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.21.1..HEAD
+ perl Porting/acknowledgements.pl v5.21.2..HEAD
=head1 Reporting Bugs