=head1 NAME

perl5115delta - what is new for perl v5.11.5

=head1 DESCRIPTION

This document describes differences between the 5.11.4 release and
the 5.11.5 release.

If you are upgrading from an earlier release such as 5.11.3, first read
L<perl5114delta>, which describes differences between 5.11.3 and
5.11.4.

=head1 Core Enhancements

=head2 32-bit limit on substr arguments removed

The 32-bit limit on C<substr> arguments has now been removed. The full range
of the system's signed and unsigned integers is now available for the C<pos>
and C<len> arguments.

=head1 Modules and Pragmata

=head2 Pragmata Changes

=over 4

=item C<version>

Upgraded from version 0.81 to 0.82.

The C<is_lax> and C<is_strict> functions can now be optionally exported to the
caller's namespace and are also now documented.

Undefined version objects are now uninitialized with zero rather than C<undef>.

=back

=head2 Updated Modules

=over 4

=item C<B::Debug>

Upgraded from version 1.11 to 1.12.

=item C<CPAN>

Upgraded from version 1.94_53 to 1.94_56.

This resolves RT #72362, in which CPAN was ignoring C<configure_requires>,
and RT #72348, in which the command C<o conf init> in the CPAN shell could
cause an exception to be thrown.

This module is also now built in a less specialized way, which resolves a
problem that caused C<make> after C<make clean> to fail, fixing RT #72218.

=item C<CPANPLUS::Dist::Build>

Upgraded from version 0.44 to 0.46.

This makes the prereq resolving fall back to F<_build/> querying if the
C<prereq_data> action fails.

=item C<Pod::Perldoc>

Upgraded from version 3.15_01 to 3.15_02.

=item C<Pod::Plainer>

Upgraded from version 1.01 to 1.02.

=item C<Safe>

Upgraded from version 2.21 to 2.22.

This resolves RT #72700, in which an exception thrown from a closure was
getting lost.

=item C<Socket>

Upgraded from version 1.85 to 1.86.

This makes the new Socket implementation of C<inet_pton> consistent with the
existing Socket6 implementation of C<inet_pton>, fixing RT #72884.

=item C<podlators>

Upgraded from version 2.2.2 to 2.3.1.

=back

=head1 Changes to Existing Documentation

The syntax C<unless (EXPR) BLOCK else BLOCK> is now documented as valid, as
is the syntax C<unless (EXPR) BLOCK elsif (EXPR) BLOCK ... else BLOCK>,
although actually using the latter may not be the best idea for the
readability of your source code.

=head1 Installation and Configuration Improvements

=head2 Configuration improvements

Support for SystemTap's C<dtrace> compatibility layer has been added and an
issue with linking C<miniperl> has been fixed in the process.

C<less -R> is now used instead of C<less> for C<groff>'s new usage of ANSI
escape codes by setting C<$Config{less}> (and thereby C<$Config{pager}>,
which fixes RT #72156.

USE_PERL_ATOF is now reported in the compile-time options listed by the C<-V>
switch.

=head1 Selected Bug Fixes

=over 4

=item *

Arbitrary whitespace is now allowed between C<NAME> and C<VERSION> in
C<package NAME VERSION;> statements. (Fixes RT #72432)

=item *

A panic caused by trying to load C<charnames> when the parser is already in
error (e.g. by a missing C<my> under C<use strict;>) is now averted. This
was a regression since Perl 5.10.0. (Fixes RT #72590)

=item *

Reading C<$!> no longer causes a SEGV for out of range C<errno> values. (Fixes
RT #72850)

=item *

A possible SEGV in C</\N{...}/> has been fixed. This was a regression since
Perl 5.10.

=item *

A possible SEGV when freeing a scalar that was upgraded to an C<SVt_REGEXP>
type from a simple(r) scalar has been fixed.

=item *

A type conversion bug in C<gmtime64> that caused it to break around C<2**48>
has been fixed.

=item *

Interpolating a regex that makes use of the C<charnames> pragma will no longer
cause a run-time error. (Fixes RT #56444)

=item *

Array references assigned to C<*Foo::ISA> now have the necessary magic added
to them to catch any further updates to the new C<@ISA>. (Fixes RT #72866)

=item *

Filehandles are now always blessed into C<IO::File>, which, together with
some suitable manipulation of C<@IO::File::ISA>, fixes a breakage introduced
in Perl 5.11.3 by a change that always blessed filehandles into C<IO::Handle>
rather than checking for C<FileHandle> first.

=item *

A change in the behaviour of C<warnings::enabled> and C<warnings::warnif> in
Perl 5.10.0 that wasn't documented at the time is now documented in
L<perl5100delta>. (Fixes RT #62522)

=item *

RT #71504 is now fixed by simply skipping the tests that failed on OpenBSD
with ithreads and perlio.

=back

=head1 New or Changed Diagnostics

=over 4

=item *

The fatal error C<Malformed UTF-8 returned by \N> is now produced if the
C<charnames> handler returns malformed UTF-8.

=item *

If an unresolved named character or sequence was encountered when compiling a
regex pattern then the fatal error C<\\N{NAME} must be resolved by the lexer>
is now produced. This can happen, for example, when using a single-quotish
context like C<$re = '\N{SPACE}'; $re;>. See L<perldiag> for more examples of
how the lexer can get bypassed.

=item *

The fatal error C<Invalid hexadecimal number in \\N{U+...}> will be produced
if the character constant represented by C<...> is not a valid hexadecimal
number. 

=item *

The new meaning of C<\N> as C<[^\n]> is not valid in a bracketed character
class, just like C<.> in a character class loses its special meaning, and will
cause the fatal error C<\\N in a character class must be a named character:
\\N{...}>.

=item *

The rules on what is legal for the C<...> in C<\N{...}> have been tightened
up so that unless the C<...> begins with an alphabetic character and continues
with a combination of alphanumerics, dashes, spaces, parentheses or colons
then the warning C<Deprecated character(s) in \\N{...} starting at '%s'> is
now issued.

=item *

The warning C<Using just the first characters returned by \N{}> will be
issued if the C<charnames> handler returns a sequence of characters which
exceeds the limit of the number of characters that can be used. The message
will indicate which characters were used and which were discarded.

=item *

Currently, all but the first of the several characters that the C<charnames>
handler may return are discarded when used in a regular expression pattern
bracketed character class. If this happens then the warning C<Using just the
first character returned by \N{} in character class> will be issued.

=item *

The warning C<Missing right brace on \\N{} or unescaped left brace after \\N.
Assuming the latter> will be issued if Perl encounters a C<\N{> but doesn't
find a matching C<}>. In this case Perl doesn't know if it was mistakenly
omitted, or if "match non-newline" followed by "match a C<{>" was desired.
It assumes the latter because that is actually a valid interpretation as
written, unlike the other case.  If you meant the former, you need to add the
matching right brace.  If you did mean the latter, you can silence this
warning by writing instead C<\N\{>.

=item *

C<gmtime> and C<localtime> called with numbers smaller than they can reliably
handle will now issue the warnings C<gmtime(%.0f) too small> and
C<localtime(%.0f) too small>.

=back

=head1 New Tests

=over 4

=item F<t/op/filehandle.t>

Tests some suitably portable filetest operators to check that they work as
expected, particularly in the light of some internal changes made in how
filehandles are blessed.

=item F<t/op/time_loop.t>

Tests that times greater than C<2**63>, which can now be handed to C<gmtime>
and C<localtime>, do not cause an internal overflow or an excessively long
loop.

=back

=head1 Known Problems

Perl 5.11.5 is a development release leading up to Perl 5.12.0.
Some notable known problems found in 5.11.5 are listed as dependencies
of RT #69710, the Perl 5 version 12 meta-ticket.

=head1 Acknowledgements

Perl 5.11.5 represents approximately one month of development since
Perl 5.11.4 and contains 9618 lines of changes across 151 files
from 33 authors and committers:

E<AElig>var ArnfjE<ouml>rE<eth> Bjarmason, Abigail, brian d foy, Chris
Williams, David Golden, David Mitchell, Eric Brine, Frank Wiegand, Gisle
Aas, H.Merijn Brand, Jan Dubois, Jesse Vincent, Jim Cromie, John Peacock,
Josh ben Jore, Karl Williamson, Marcus Holland-Moritz, Michael G Schwern,
Nicholas Clark, Offer Kaye, Philippe Bruhat (BooK), Rafael Garcia-Suarez,
Reini Urban, Ricardo Signes, Robin Barker, Slaven Rezic, Steffen Mueller,
Steve Hay, Steve Peters, Tim Bunce, Todd Rinaldo, Tony Cook and
Vincent Pit.

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.

=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 B<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
analyzed 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 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
