path: root/pod/perldelta.pod

=encoding utf8

=head1 NAME

perldelta - what is new for perl v5.17.10

=head1 DESCRIPTION

This document describes differences between the 5.17.9 release and the 5.17.10
release.

If you are upgrading from an earlier release such as 5.17.8, first read
L<perl5179delta>, which describes differences between 5.17.8 and 5.17.9.

=head1 Notice

=head1 Core Enhancements

=head1 Security

=head2 Hash iteration randomized per hash variable

Every hash has its own iteration order, which
should make it much more difficult to determine what the current hash
seed is.

=head1 Incompatible Changes

=head2 Explicit rules for variable names and identifiers

Due to an oversight, length-one variable names in 5.16 were completely
unrestricted, and opened the door to several kinds of insanity.  As of
5.18, these now follow the rules of other identifiers, in addition
to accepting characters that match the \p{POSIX_Punct} property.

There are no longer any differences in the parsing of identifiers specified
as $... or ${...}; previously, they were dealt with in different parts of
the core, and so had slightly different behavior. For instance,
C<${foo:bar}> was a legal variable name.  Since they are now both parsed
by the same code, that is no longer the case.

[ List each incompatible change as a =head2 entry ]

=head1 Deprecations

=head2 PL_sv_objcount

This interpreter-global variable used to track the total number of
Perl objects in the interpreter. It is no longer maintained and will
be removed altogether in Perl 5.20.

=head1 Performance Enhancements

=head1 Modules and Pragmata

=head2 New Modules and Pragmata

=over 4

=item *

L<Config::Perl::V> 0.17 has been added to the Perl core.

=back

=head2 Updated Modules and Pragmata

=over 4

=item *

L<Archive::Extract> has been upgraded from version 0.62 to 0.68.

NOTE: L<Archive::Extract> is deprecated and may be removed from a future version of Perl.

=item *

L<Attribute::Handlers> has been upgraded from version 0.93 to 0.94.

=item *

L<B::Lint> has been upgraded from version 1.14 to 1.17.

NOTE: L<B::Lint> is deprecated and may be removed from a future version of Perl.

=item *

L<Benchmark> has been upgraded from version 1.14 to 1.15.

This reverts (for now) a change in 1.14 whereby the "too few iterations"
message became a warning on STDERR instead of being output on STDOUT. It's
now on STDOUT again.

=item *

L<bignum> has been upgraded from version 0.31 to 0.32.

=item *

L<CPAN> has been upgraded from version 1.99_51 to 2.00.

=item *

L<CPANPLUS> has been upgraded from version 0.9133 to 0.9135.

NOTE: L<CPANPLUS> is deprecated and may be removed from a future version of Perl.

=item *

L<CPANPLUS::Dist::Build> has been upgraded from version 0.68 to 0.70.

NOTE: L<CPANPLUS::Dist::Build> is deprecated and may be removed from a future version of Perl.

=item *

L<Data::Dumper> has been upgraded from version 2.141 to 2.142.

=item *

L<DBM_Filter> has been upgraded from version 0.04 to 0.05.

=item *

L<Digest::SHA> has been upgraded from version 5.81 to 5.82.

=item *

L<Encode> has been upgraded from version 2.47 to 2.48.

=item *

L<ExtUtils::Manifest> has been upgraded from version 1.62 to 1.63.

=item *

L<File::CheckTree> has been upgraded from version 4.41 to 4.42.

=item *

L<File::DosGlob> has been upgraded from version 1.09 to 1.10.

=item *

L<File::Temp> has been upgraded from version 0.22 to 0.22_90.

=item *

L<Filter::Simple> has been upgraded from version 0.88 to 0.89.

=item *

L<IO> has been upgraded from version 1.26 to 1.27.

=item *

L<Log::Message> has been upgraded from version 0.04 to 0.06.

NOTE: L<Log::Message> is deprecated and may be removed from a future version of Perl.

=item *

L<Log::Message::Simple> has been upgraded from version 0.08 to 0.10.

NOTE: L<Log::Message::Simple> is deprecated and may be removed from a future version of Perl.

=item *

L<Math::BigInt> has been upgraded from version 1.998 to 1.999.

=item *

L<Module::CoreList> has been upgraded from version 2.80 to 2.85.

=item *

L<Module::Load> has been upgraded from version 0.22 to 0.24.

=item *

L<Module::Pluggable> has been upgraded from version 4.5 to 4.6.

NOTE: L<Module::Pluggable> is deprecated and may be removed from a future version of Perl.

=item *

L<Net::Ping> has been upgraded from version 2.39 to 2.41.

This fixes some test failures on Windows.

=item *

L<Object::Accessor> has been upgraded from version 0.44 to 0.46.

NOTE: L<Object::Accessor> is deprecated and may be removed from a future version of Perl.

=item *

L<overload> has been upgraded from version 1.20 to 1.21.

=item *

L<Perl::OSType> has been upgraded from version 1.002 to 1.003.

This fixes a bug detecting the VOS operating system.

=item *

L<PerlIO::scalar> has been upgraded from version 0.15 to 0.16.

=item *

L<Pod::Checker> has been upgraded from version 1.51 to 1.60.

=item *

L<Pod::Html> has been upgraded from version 1.17 to 1.18.

=item *

L<Pod::Parser> has been upgraded from version 1.51 to 1.60.

=item *

L<Pod::Perldoc> has been upgraded from version 3.17 to 3.19.

=item *

L<Pod::Usage> has been upgraded from version 1.51 to 1.61.

=item *

L<SelfLoader> has been upgraded from version 1.20 to 1.21.

=item *

L<Term::UI> has been upgraded from version 0.32 to 0.34.

NOTE: L<Term::UI> is deprecated and may be removed from a future version of Perl.

=item *

L<Test::Harness> has been upgraded from version 3.25_01 to 3.26.

=item *

L<Text::Soundex> has been upgraded from version 3.03_01 to 3.04.

=item *

L<Thread::Queue> has been upgraded from version 3.01 to 3.02.

=item *

L<Unicode::UCD> has been upgraded from version 0.47 to 0.50.

=item *

L<warnings> has been upgraded from version 1.16 to 1.17.

=item *

L<Win32> has been upgraded from version 0.45 to 0.46.

=item *

L<Win32API::File> has been upgraded from version 0.1200 to 0.1201.

=back

=head1 Documentation

=head2 Changes to Existing Documentation

=head3 L<perlrebackslash/\N>

=over 4

=item *

This feature is no longer experimental.

=back

=head1 Diagnostics

The following additions or changes have been made to diagnostic output,
including warnings and fatal error messages.  For the complete list of
diagnostic messages, see L<perldiag>.

=head2 New Diagnostics

=head3 New Warnings

=over 4

=item *

L%c* is deprecated, and will become a syntax error|perldiag/"%c* is deprecated, and will become a syntax error">

Use of C<@*>, C<&*>, C<**> or C<%*> is now deprecated, and will generate a
compile time warning, enabled by default.  In future such code will fail to
compile with a syntax error.  Removing these variables, along with C<$*>,
will permit future syntax additions.

=back

=head2 Changes to Existing Diagnostics

=over 4

=item *

L<$* is no longer supported, and will become a syntax error|perldiag/"$* is no longer supported, and will become a syntax error">

The warning that use of C<$*> and C<$#> is no longer supported is now
generated for every location that references them.  Previously it would fail
to be generated if another variable using the same typeglob was seen first
(e.g. C<@*> before C<$*>), and would not be generated for the second and
subsequent uses.  (It's hard to fix the failure to generate warnings at all
without also generating them every time, and warning every time is
consistent with the warnings that C<$[> used to generate.)

=back

=head1 Internal Changes

=over 4

=item *

The new copy-on-write mechanism that was introduced in 5.17.7 has now been
disabled by default, since it was felt that there were too many rough
edges for the 5.18 release. It is expected that it will be enabled by
default for 5.20.

This change also re-enables PL_sawampersand by default.

It can be enabled in a perl build by running F<Configure> with
B<-Accflags=-DPERL_NEW_COPY_ON_WRITE>, and we would encourage XS authors to
try their code with such an enabled perl, and provide feedback.
XXX need blurb, e.g. a reference to a new section in perlguts or perlxs
explaining how XS authors should handle COW strings.

=back

=head1 Selected Bug Fixes

=over 4

=item *

Fix two crashes in the debugger when using Frame=2 or autotrace.  These are
[perl #116769] and [perl #116771].

=back

=head1 Acknowledgements

Perl 5.17.10 represents approximately 4 weeks of development since Perl 5.17.9
and contains approximately 77,000 lines of changes across 440 files from 42
authors.

Perl continues to flourish into its third decade thanks to a vibrant community
of users and developers. The following people are known to have contributed the
improvements that became Perl 5.17.10:

Aaron Crane, Aaron Trevena, Andrew Tam, Andy Dougherty, Anton Nikishaev, Brad
Gilbert, Brian Fraser, Charlie Gonzalez, Chris 'BinGOs' Williams, Craig A.
Berry, Daniel Dragan, David Golden, David Mitchell, Dominic Hargreaves, Florian
Ragwitz, George Greer, H.Merijn Brand, James E Keenan, Jasmine Ahuja, John
Goodyear, John Peacock, Karl Williamson, Kent Fredric, Lukas Mai, Max
Maischein, Nicholas Clark, Patrik Hägglund, Paul Green, Peter Martini, Rafael
Garcia-Suarez, Renee Baecker, Ricardo Signes, Ruslan Zakirov, Salvador
Fandiño, Scott Lanning, Shirakata Kentaro, Steffen Müller, Steve Hay, Steve
Peters, Sullivan Beck, Tony Cook, Yves Orton.

The list above is almost certainly incomplete as it is automatically generated
from version control history. In particular, it does not include the names of
the (very much appreciated) contributors who reported issues to the Perl bug
tracker.

Many of the changes included in this version originated in the CPAN modules
included in Perl's core. We're grateful to the entire CPAN community for
helping Perl to flourish.

For a more complete list of all of Perl's historical contributors, please see
the F<AUTHORS> file in the Perl source distribution.

=head1 Reporting Bugs

If you find what you think is a bug, you might check the articles recently
posted to the comp.lang.perl.misc newsgroup and the perl bug database at
http://rt.perl.org/perlbug/ .  There may also be information at
http://www.perl.org/ , the Perl Home Page.

If you believe you have an unreported bug, please run the L<perlbug> program
included with your release.  Be sure to trim your bug down to a tiny but
sufficient test case.  Your bug report, along with the output of C<perl -V>,
will be sent off to perlbug@perl.org to be analysed by the Perl porting team.

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
unarchived mailing list, which includes all the core committers, who will 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
security issues in the Perl core, not for modules independently distributed on
CPAN.

=head1 SEE ALSO

The F<Changes> file for an explanation of how to view exhaustive details on
what changed.

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=cut