=encoding utf8

=head1 NAME

perl5255delta - what is new for perl v5.25.5

=head1 DESCRIPTION

This document describes differences between the 5.25.4 release and the 5.25.5
release.

If you are upgrading from an earlier release such as 5.25.3, first read
L<perl5254delta>, which describes differences between 5.25.3 and 5.25.4.

=head1 Security

=head2 "Escaped" colons and relative paths in PATH

On Unix systems, Perl treats any relative paths in the PATH environment
variable as tainted when starting a new process.  Previously, it was
allowing a backslash to escape a colon (unlike the OS), consequently
allowing relative paths to be considered safe if the PATH was set to
something like C</\:.>.  The check has been fixed to treat C<.> as tainted
in that example.

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<Filter::Simple> has been upgraded from version 0.92 to 0.93.

It no longer treats C<no MyFilter> immediately following C<use MyFilter> as
end-of-file.  [perl #107726]

=item *

L<Locale::Codes> has been upgraded from 3.39 to 3.40.

=item *

L<Module::CoreList> has been upgraded from version 5.20160820 to 5.20160920.

=item *

L<POSIX> has been upgraded from version 1.71 to 1.72.

=item *

L<Sys::Syslog> has been upgraded from version 0.34_01 to 0.35.

=item *

L<Test::Simple> has been upgraded from version 1.302052 to 1.302056.

=item *

L<Thread::Semaphore> has been upgraded from 2.12 to 2.13.

Added the C<down_timed> method.

=item *

L<XSLoader> has been upgraded from version 0.22 to 0.24.

=back

=head1 Documentation

=head2 Changes to Existing Documentation

=head3 L<perlinterp>

=over 4

=item *

L<perlinterp> has been expanded to give a more detailed example of how to
hunt around in the parser for how a given operator is handled.

=back

=head1 Testing

=over 4

=item *

F<t/re/regexp_nonull.t> has been added to test that the regular expression
engine can handle scalars that do not have a null byte just past the end of
the string.

=back

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item VMS

=over 4

=item *

The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
now a colon (C<:>) when running under a Unix shell. There is no change when
running under DCL (it's still C<|>).

=item *

Remove some VMS-specific hacks from C<showlex.t>. These were added 15 years
ago, and are no longer necessary for any VMS version now supported.

=back

=back

=over 4

=item Win32

=over 4

=item *

Tweaks for Win32 VC vs GCC detection makefile code. This fixes issue that CCHOME
depends on CCTYPE, which in auto detect mode is set after CCHOME, so CCHOME uses
the uninit CCTYPE var. Also fix else vs .ELSE in makefile.mk

=back

=back

=head1 Internal Changes

=over 4

=item *

Several macros and functions have been added to the public API for
dealing with Unicode and UTF-8-encoded strings.  See
L<perlapi/Unicode Support>.

=item *

Use C<my_strlcat()> in C<locale.c>. While C<strcat()> is safe in this context,
some compilers were optimizing this to C<strcpy()> causing a porting test to
fail that looks for unsafe code. Rather than fighting this, we just use
C<my_strlcat()> instead.

=back

=head1 Selected Bug Fixes

=over 4

=item *

Invalid assignments to a reference constructor (e.g., C<\eval=time>) could
sometimes crash in addition to giving a syntax error.  [perl #125679]

=item *

The parser could sometimes crash if a bareword came after C<evalbytes>.
[perl #129196]

=item *

Autoloading via a method call would warn erroneously ("Use of inherited
AUTOLOAD for non-method") if there was a stub present in the package into
which the invocant had been blessed.  The warning is no longer emitted in
such circumstances.  [perl #47047]

=item *

A sub containing with a "forward" declaration with the same name (e.g.,
C<sub c { sub c; }>) could sometimes crash or loop infinitely.  [perl
#129090]

=item *

The use of C<splice> on arrays with nonexistent elements could cause other
operators to crash.  [perl #129164]

=item *

Fixed case where C<re_untuit_start> will overshoot the length of a utf8
string. [perl #129012]

=item *

Handle C<CXt_SUBST> better in C<Perl_deb_stack_all>, previously it wasn't
checking that the I<current> C<cx> is the right type, and instead was always
checking the base C<cx> (effectively a noop). [perl #129029]

=item *

Fixed two possible use-after-free bugs in C<Perl_yylex>. C<Perl_yylex>
maintains up to two pointers into the parser buffer, one of which can
become stale under the right conditions. [perl #129069]

=item *

Fixed a crash with C<s///l> where it thought it was dealing with UTF-8
when it wasn't. [perl #129038]

=item *

Fixed place where regex was not setting the syntax error correctly.
[perl #129122]

=item *

The C<&.> operator (and the C<&> operator, when it treats its arguments as
strings) were failing to append a trailing null byte if at least one string
was marked as utf8 internally.  Many code paths (system calls, regexp
compilation) still expect there to be a null byte in the string buffer
just past the end of the logical string.  An assertion failure was the
result.  [perl #129287]

=item *

Check C<pack_sockaddr_un()>'s return value because C<pack_sockaddr_un()>
silently truncates the supplied path if it won't fit into the C<sun_path>
member of C<sockaddr_un>. This may change in the future, but for now
check the path in theC<sockaddr> matches the desired path, and skip if
it doesn't. [perl #128095]

=item *

Make sure C<PL_oldoldbufptr> is preserved in C<scan_heredoc()>. In some
cases this is used in building error messages. [perl #128988]

=item *

Check for null PL_curcop in IN_LC() [perl #129106]

=item *

Fixed the parser error handling for an 'C<:attr(foo>' that does not have
an ending 'C<)>'.

=item *

Fix C<Perl_delimcpy()> to handle a backslash as last char, this
actually fixed two bugs, [perl #129064] and [perl #129176].

=item *

[perl #129267] rework gv_fetchmethod_pvn_flags separator parsing to
prevent possible string overrun with invalid len in gv.c

=back

=head1 Obituary

Jon Portnoy (AVENJ), a prolific Perl author and admired Gentoo community
member, has passed away on August 10, 2016. He will be remembered and
missed by all those with which he came in contact and enriched with his
intellect, wit, and spirit.

=head1 Acknowledgements

Perl 5.25.5 represents approximately 4 weeks of development since Perl 5.25.4
and contains approximately 67,000 lines of changes across 230 files from 25
authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 62,000 lines of changes to 160 .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 5.25.5:

Aaron Crane, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry,
Dagfinn Ilmari Mannsåker, Dan Collins, Daniel Dragan, Dave Cross, David
Mitchell, E. Choroba, Father Chrysostomos, James E Keenan, Jerry D. Hedden,
Karl Williamson, Lukas Mai, Ricardo Signes, Rick Delaney, Sawyer X, Stevan
Little, Steve Hay, Sullivan Beck, Theo Buehler, Tony Cook, Yaroslav Kuzmin,
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 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 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