List 5.16 blockers in 'Known Problems' in perldelta

[perl5.git] / pod / perldelta.pod

=encoding utf8

=head1 NAME

perldelta - what is new for perl v5.15.9

=head1 DESCRIPTION

This document describes differences between the 5.15.8 release and
the 5.15.9 release.

If you are upgrading from an earlier release such as 5.15.7, first read
L<perl5158delta>, which describes differences between 5.15.7 and
5.15.8.

=head1 Notice

This space intentionally left blank.

=head1 Core Enhancements

=head2 C<< no feature; >> now means reset to default

C<< no feature >> now resets to the default feature set.  To disable all
features (which is likely to be a pretty special-purpose request, since
it presumably won't match any named set of semantics) you can now  
write C<< no feature ':all' >>.

=head1 Security

=head2 Malformed UTF-8 input could cause attempts to read beyond the end of the buffer

Two new XS-accessible functions, C<utf8_to_uvchr_buf()> and
C<utf8_to_uvuni_buf()> are now available to prevent this, and the Perl
core has been converted to use them.
See L</Internal Changes>.

=head1 Incompatible Changes

=head2 C<< no feature; >>

C<no feature;> now means reset to default.

=head1 Deprecations

=head2 Literal C<< "{" >> characters in regular expressions.

It has been documented that the current plans include requiring a
literal C<< "{" >> to be escaped: 5.18 will emit deprecation warnings,
and it will be required in 5.20.

=head2 XS functions C<utf8_to_uvchr()> and C<utf8_to_uvuni()>

Use C<utf8_to_uvchr_buf()> and C<utf8_to_uvuni_buf()> instead.
See L</Internal Changes>.

=head1 Performance Enhancements

=over 4

=item *

Fix a slowdown in freeing nested hashes. This may speedup the exit of 
certain programs.

=back

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

C<attributes> has been upgraded from version 0.17 to 0.18.

=item *

C<charnames> has been upgraded from version 1.29 to 1.30.

=item *

C<feature> has been upgraded from version 1.26 to 1.27.

C<no feature;> now means reset to default. The code has been refactored
to reduce duplication.

=item *

C<B::Deparse> has been upgraded from version 1.12 to 1.13.

=item *

C<B::Lint> has been upgraded from version 1.13 to 1.14.

=item *

C<CPAN::Meta> has been upgraded from version 2.120351 to 2.120630.

=item *

C<CPANPLUS> has been upgraded from version 0.9118 to 0.9121.

=item *

C<Data::Dumper> has been upgraded from version 2.135_05 to 2.135_06.

=item *

C<Digest::SHA> has been upgraded from version 5.70 to 5.71.

=item *

C<ExtUtils::CBuilder> has been upgraded from version 0.280205 to 0.280206.

=item *

C<HTTP::Tiny> has been upgraded from version 0.016 to 0.017.

=item *

C<Module::CoreList> has been upgraded from version 2.60 to 2.63.

=item *

C<Pod::Html> has been upgraded from version 1.14 to 1.1501.

=item *

C<Pod::Perldoc> has been upgraded from version 3.15_15 to 3.17.

=item *

C<Pod::Simple> has been upgraded from version 3.19 to 3.20.

=item *

C<Socket> has been upgraded from version 1.98 to 2.000.

=item *

C<Term::ReadLine> has been upgraded from version 1.08 to 1.09.

=item *

C<Unicode::Collate> has been upgraded from version 0.87 to 0.89.

=item *

C<Unicode::Normalize> has been upgraded from version 1.13 to 1.14.

=item *

C<Unicode::UCD> has been upgraded from version 0.41 to 0.42.

=item *

C<XS::APItest> has been upgraded from version 0.36 to 0.37.

=back


=head1 Documentation

There has been no significant change in the documentation between 
5.15.8 and 5.15.9.

=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 Errors

Compared to 5.15.8, 5.15.9 does not introduce new errors.

=head3 New Warnings

Compared to 5.15.8, 5.15.9 does not introduce new errors, but see
L</Changes to Existing Diagnostics>

=head2 Changes to Existing Diagnostics

=over 4

=item *

L<lvalue attribute %s already-defined subroutine|perldiag/"lvalue attribute %s already-defined subroutine">, which replaces
C<< lvalue attribute cannot be removed after the subroutine has been defined >>.

=back

=head1 Utility Changes

No utilities changed between 5.15.8 and 5.15.9.

=head1 Configuration and Compilation

=over 4

=item *

C<< perlfunc.html >> is now being generated again. [perl #107870]

=back

=head1 Testing

=over 4

=item *

F<< t/op/require_37033.t >> has been added, to test that C<require>
always closes the file handle that it opens. Previously, it had been
leaking the file handle if it happened to have file descriptor 0, which
would happen if C<require> was called (explicitly or implicitly) when
C<STDIN> had been closed.

=back

=head1 Platform Support

There have been no changes to Perl's support of various platforms between
5.15.8 and 5.15.9.

=head1 Internal Changes

=over 4

=item *

Two new functions C<utf8_to_uvchr_buf()> and C<utf8_to_uvuni_buf()> have
been added.  These are the same as C<utf8_to_uvchr> and
C<utf8_to_uvuni> (which are now deprecated), but take an extra parameter
that is used to guard against reading beyond the end of the input
string.
See L<perlapi/utf8_to_uvchr_buf> and L<perlapi/utf8_to_uvuni_buf>.

=item *

The regular expression engine now does TRIE case insensitive matches
under Unicode. This may change the output of C<< use re 'debug'; >>,
and will speed up various things.

=back

=head1 Selected Bug Fixes

=over 4

=item *

I<Takri> now matches two more characters under the C<Script_Extensions>
property. This corrects a Unicode 6.1 omission.

=item *

C<< perlfunc.html >> is now being generated again. [perl #107870]

=item *

C<< $$ >> is no longer tainted. Since this value comes directly from
C<< getpid() >>, it is always safe.

=item *

Fix leaking a file handle. [perl #37033]

=item *

An off-by-one error caused C<< /[:upper:]/ >> and C<< /[:punct:]/ >> to
unexpectedly match characters with code points above 255. This has been
rectified. [perl 111400].

=item *

C<< (?foo: ...) >> no longer loses passed in character set.

=item *

Allow attributes to set C<< :lvalue >> on a defined sub. [perl 107366].

=item *

C<< die; >> with a non-reference, non-string value in $@ now properly
propagates that value [perl #111654].

=item *

C<< Term::ReadLine >> now uses AnyEvent instead of Tk for an event loop.

=back

=head1 Known Problems

This is a list of some significant unfixed bugs, which need to be
resolved before 5.16.0

=over 4

=item F<< op/sigdispatch.t >> fails alarm test 14 and gets killed [perl #89718]

=item Perl crash due to wrong delimiter in C<< PATH >> environment [perl #94846]

It's possible to crash Win32 if the wrong delimiter is used.

=item Corrupt UTF8 [perl #79960, #100058]

It is possible to read an invalid UTF8 character, but have it marked valid,
or to incorrectly read UTF8 characters if C<< $/ >> is set to read fixed
length records.

=item UTF8 patches for 5.16 [perl #107008]

Brian Fraser's work on UTF8 needs futher integration.

=item C<eval { 'fork()' }> is broken on Windows [perl #109718]

This is a known test failure to be fixed before 5.16.0. 

=item Warnings from cpan/IO-Compress [perl #110736]

Some tests in F<< cpan/IO-Compress/t/cz-03zlib-v1.t >> issues a 
"isn't numeric" warning in blead, but not in maint.

=item C<< Pod-Html >> test failures on Windows.

A number of tests for C<< Pod::Html >> fail under Windows, due to an 
incorrect assumption by the test scripts about capitalization of the
network drive.

=back

=head1 Acknowledgements

XXX Redo this on 2012-03-20

Perl 5.15.9 represents approximately 4 weeks of development since Perl 5.15.8
and contains approximately 74,000 lines of changes across 470 files from 23
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 5.15.9:

Aaron Crane, Abigail, Chris 'BinGOs' Williams, Craig A. Berry, Dave Rolsky,
David Cantrell, David Golden, David Mitchell, Eric Brine, Father Chrysostomos,
Florian Ragwitz, James E Keenan, Jesse Vincent, Karl Williamson, Marc Green,
Max Maischein, Nicholas Clark, Pau Amma, Reini Urban, Ricardo Signes, Tony
Cook, Yves Orton, Zefram.

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.

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