PERL5212DELTA(1pm) Perl Programmers Reference Guide PERL5212DELTA(1pm)
NAME
perl5212delta - what is new for perl v5.21.2
DESCRIPTION
This document describes differences between the 5.21.1 release and the
5.21.2 release.
If you are upgrading from an earlier release such as 5.21.0, first read
perl5211delta, which describes differences between 5.21.0 and 5.21.1.
Core Enhancements
Better heuristics on older platforms for determining locale UTF8ness
On platforms that implement neither the C99 standard nor the POSIX 2001
standard, determining if the current locale is UTF8 or not depends on
heuristics. These are improved in this release.
Security
Perl is now always compiled with -D_FORTIFY_SOURCE=2 if available
The 'code hardening' option called "_FORTIFY_SOURCE", available in gcc
4.*, is now always used for compiling Perl, if available.
Note that this isn't necessarily a huge step since in many platforms
the step had already been taken several years ago: many Linux
distributions (like Fedora) have been using this option for Perl, and
OS X has enforced the same for many years.
Deprecations
"/\C/" character class
This character class, which matches a single byte, even if it appears
in a multi-byte character has been deprecated. Matching single bytes in
a multi-byte character breaks encapsulation, and can corrupt utf8
strings.
Performance Enhancements
o Refactoring of "pp_tied" and C"pp_ref" for small improvements.
o Pathtools don't try to load XS on miniperl.
o A typo fix reduces the size of the "OP" structure.
o Hash lookups where the key is a constant is faster.
Modules and Pragmata
Updated Modules and Pragmata
o arybase has been upgraded from version 0.07 to 0.08.
o B has been upgraded from version 1.49 to 1.50.
o Devel::Peek has been upgraded from version 1.17 to 1.18.
o experimental has been upgraded from version 0.007 to 0.008.
o ExtUtils::Manifest has been upgraded from version 1.63 to 1.64.
o File::Copy has been upgraded from version 2.29 to 2.30.
o The PathTools module collection (File::Spec and friends) has been
upgraded from version 3.48 to 3.49.
o Filter::Simple has been upgraded from version 0.91 to 0.92.
o Hash::Util has been upgraded from version 0.17 to 0.18.
o IO has been upgraded from version 1.32 to 1.33.
o IO::Socket::IP has been upgraded from version 0.29 to 0.31.
A better fix for subclassing "connect()". [cpan #95983]
<https://rt.cpan.org/Ticket/Display.html?id=95983> [cpan #97050]
<https://rt.cpan.org/Ticket/Display.html?id=97050>
o IPC::Open3 has been upgraded from version 1.16 to 1.17.
o Math::BigInt has been upgraded from version 1.9995 to 1.9996.
Correct handling of subclasses. [cpan #96254]
<https://rt.cpan.org/Ticket/Display.html?id=96254> [cpan #96329]
<https://rt.cpan.org/Ticket/Display.html?id=96329>
o Module::CoreList has been upgraded from version 5.021001_01 to
5.021002.
o Pod::Usage has been upgraded from version 1.63 to 1.64.
o POSIX has been upgraded from version 1.40 to 1.41.
o threads has been upgraded from version 1.94 to 1.95.
o warnings has been upgraded from version 1.24 to 1.26.
Documentation
Changes to Existing Documentation
perlpolicy
o We now have a code of conduct for the p5p mailing list, as
documented in "STANDARDS OF CONDUCT" in perlpolicy.
perlfunc
o Improve documentation of "our".
perlsyn
o The empty conditional in "for" and "while" is now documented in
perlsyn.
Diagnostics
New Diagnostics
New Warnings
o Argument "%s" treated as 0 in increment (++)
(W numeric) The indicated string was fed as an argument to the "++"
operator which expects either a number or a string matching
"/^[a-zA-Z]*[0-9]*\z/". See "Auto-increment and Auto-decrement" in
perlop for details.
o Redundant argument in %s
(W redundant) You called a function with more arguments than other
arguments you supplied indicated would be needed. Currently only
emitted when a printf-type format required fewer arguments than
were supplied, but might be used in the future for e.g. "pack" in
perlfunc.
The warnings category "redundant" is new. See also [RT #121025]
Configuration and Compilation
o A new compilation flag, "-DPERL_OP_PARENT" is available. For
details, see the discussion below at "Internal Changes".
Testing
o "test.pl" now allows "plan skip_all => $reason", to make it more
compatible with "Test::More".
Platform Support
Platform-Specific Notes
Solaris
Builds on Solaris 10 with "-Dusedtrace" would fail early since make
didn't follow implied dependencies to build "perldtrace.h". Added
an explicit dependency to "depend". [perl #120120]
<https://rt.perl.org/Ticket/Display.html?id=120120>
Internal Changes
o The following private API functions had their context parameter
removed, "Perl_cast_ulong", "Perl_cast_i32", "Perl_cast_iv",
"Perl_cast_uv", "Perl_cv_const_sv", "Perl_mg_find",
"Perl_mg_findext", "Perl_mg_magical", "Perl_mini_mktime",
"Perl_my_dirfd", "Perl_sv_backoff", "Perl_utf8_hop".
Users of the public API prefix-less calls remain unaffected.
o Experimental support for ops in the optree to be able to locate
their parent, if any. A general-purpose function,
"op_sibling_splice()" allows for general manipulating an
"op_sibling" chain. The last op in such a chain is now marked with
the field "op_lastsib".
A new build define, "-DPERL_OP_PARENT" has been added; if given, it
forces the core to use "op_lastsib" to detect the last sibling in a
chain, freeing the last "op_sibling" pointer, which then points
back to the parent (instead of being "NULL").
A C-level "op_parent()" function, and a "B" "parent()" method have
been added; under a default build, they return "NULL", but when
"-DPERL_OP_PARENT" has been set, they return the parent of the
current op.
Selected Bug Fixes
o "s///e" on tainted utf8 strings got "pos()" messed up. This bug,
introduced in 5.20, is now fixed. [RT #122148]
o A non-word boundary in a regular expression ("\B") did not always
match the end of the string; in particular "q{} =~ /\B/" did not
match. This bug, introduced in perl 5.14, is now fixed. [RT
#122090]
o "" P" =~ /(?=.*P)P/" should match, but did not. This is now fixed.
[RT #122171].
Acknowledgements
Perl 5.21.2 represents approximately 4 weeks of development since Perl
5.21.1 and contains approximately 11,000 lines of changes across 220
files from 27 authors.
Excluding auto-generated files, documentation and release tools, there
were approximately 5,700 lines of changes to 140 .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 5.21.2:
Aaron Crane, Abhijit Menon-Sen, Abigail, Alexandr Ciornii, brian d foy,
Brian Fraser, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan,
David Golden, David Mitchell, Dmitri Tikhonov, George Greer, H.Merijn
Brand, James E Keenan, Jarkko Hietaniemi, Karen Etheridge, Karl
Williamson, Matthew Horsfall, Peter John Acklam, Peter Martini, Reini
Urban, Ricardo Signes, Steve Hay, Tony Cook, Yves Orton, AEvar
Arnfjoer` Bjarmason.
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 AUTHORS file in the Perl source distribution.
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 https://rt.perl.org/ . 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 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 "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.
SEE ALSO
The Changes file for an explanation of how to view exhaustive details
on what changed.
The INSTALL file for how to build Perl.
The README file for general stuff.
The Artistic and Copying files for copyright information.
perl v5.22.0 2015-05-13 PERL5212DELTA(1pm)
perl 5.22 - Generated Fri Aug 14 15:17:19 CDT 2015