=encoding utf8

=head1 NAME

perl52711delta - what is new for perl v5.27.11

=head1 DESCRIPTION

This document describes differences between the 5.27.10 release and the 5.27.11
release.

If you are upgrading from an earlier release such as 5.27.9, first read
L<perl52710delta>, which describes differences between 5.27.9 and 5.27.10.

=head1 Security

=head2 [CVE-2017-12837] Heap buffer overflow in regular expression compiler

Compiling certain regular expression patterns with the case-insensitive
modifier could cause a heap buffer overflow and crash perl.  This has now been
fixed.
L<[perl #131582]|https://rt.perl.org/Public/Bug/Display.html?id=131582>

=head2 [CVE-2017-12883] Buffer over-read in regular expression parser

For certain types of syntax error in a regular expression pattern, the error
message could either contain the contents of a random, possibly large, chunk of
memory, or could crash perl.  This has now been fixed.
L<[perl #131598]|https://rt.perl.org/Public/Bug/Display.html?id=131598>

=head2 [CVE-2017-12814] C<$ENV{$key}> stack buffer overflow on Windows

A possible stack buffer overflow in the C<%ENV> code on Windows has been fixed
by removing the buffer completely since it was superfluous anyway.
L<[perl #131665]|https://rt.perl.org/Public/Bug/Display.html?id=131665>

=head1 Performance Enhancements

=over 4

=item *

The start up overhead for creating regular expression patterns with
Unicode properties (C<\p{...}>) has been greatly reduced in most cases.

=back

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<bytes> has been upgraded from version 1.05 to 1.06.

=item *

L<Carp> has been upgraded from version 1.49 to 1.50.

=item *

L<Devel::PPPort> has been upgraded from version 3.39 to 3.40.

=item *

L<Exporter> has been upgraded from version 5.72 to 5.73.

=item *

L<ExtUtils::Constant> has been upgraded from version 0.24 to 0.25.

=item *

L<I18N::Langinfo> has been upgraded from version 0.16 to 0.17.

=item *

L<IO> has been upgraded from version 1.38 to 1.39.

=item *

L<Module::CoreList> has been upgraded from version 5.20180221 to 5.20180420.

=item *

L<POSIX> has been upgraded from version 1.83 to 1.84.

=item *

L<subs> has been upgraded from version 1.02 to 1.03.

=item *

L<Time::HiRes> has been upgraded from version 1.9757 to 1.9759.

=item *

L<vars> has been upgraded from version 1.03 to 1.04.

=item *

L<version> has been upgraded from version 0.9918 to 0.9923.

=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>

XXX Description of the purpose of the new file here

=head2 Changes to Existing Documentation

We have attempted to update the documentation to reflect the changes
listed in this document.  If you find any we have missed, send email
to L<perlbug@perl.org|mailto:perlbug@perl.org>.

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.

Additionally, the following selected changes have been made:

=head3 L<XXX>

=over 4

=item *

XXX Description of the change here

=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>.

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">

=back

=head3 New Warnings

=over 4

=item *

XXX L<message|perldiag/"message">

=back

=head2 Changes to Existing Diagnostics

XXX Changes (i.e. rewording) of diagnostic messages go here

=over 4

=item *

XXX Describe change here

=back

=head1 Acknowledgements

Perl 5.27.11 represents approximately 4 weeks of development since Perl
5.27.10 and contains approximately 440,000 lines of changes across 200 files
from 21 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 440,000 lines of changes to 88 .pm, .t, .c and .h files.

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 5.27.11:

Aaron Crane, Alexandr Savca, Chris 'BinGOs' Williams, Dagfinn Ilmari
Mannsåker, Daniel Dragan, David Mitchell, H.Merijn Brand, James E Keenan,
John Peacock, Karl Williamson, Marc-Philip Werner, Nicholas Clark, Pali,
Ricardo Signes, Sawyer X, Sergey Aleynikov, Steve Hay, Todd Rinaldo, 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 perl bug database
at L<https://rt.perl.org/> .  There may also be information at
L<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 see
L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
for details of how to report the issue.

=head1 Give Thanks

If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
you can do so by running the C<perlthanks> program:

    perlthanks

This will send an email to the Perl 5 Porters list with your show of thanks.

=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
