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database/perl/lib/pods/perl5203delta.pod

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+=encoding utf8
+
+=head1 NAME
+
+perl5203delta - what is new for perl v5.20.3
+
+=head1 DESCRIPTION
+
+This document describes differences between the 5.20.2 release and the 5.20.3
+release.
+
+If you are upgrading from an earlier release such as 5.20.1, first read
+L<perl5202delta>, which describes differences between 5.20.1 and 5.20.2.
+
+=head1 Incompatible Changes
+
+There are no changes intentionally incompatible with 5.20.2.  If any exist,
+they are bugs, and we request that you submit a report.  See L</Reporting Bugs>
+below.
+
+=head1 Modules and Pragmata
+
+=head2 Updated Modules and Pragmata
+
+=over 4
+
+=item *
+
+L<Errno> has been upgraded from version 1.20_05 to 1.20_06.
+
+Add B<-P> to the pre-processor command-line on GCC 5.  GCC added extra line
+directives, breaking parsing of error code definitions.
+L<[perl #123784]|https://rt.perl.org/Ticket/Display.html?id=123784>
+
+=item *
+
+L<Module::CoreList> has been upgraded from version 5.20150214 to 5.20150822.
+
+Updated to cover the latest releases of Perl.
+
+=item *
+
+L<perl5db.pl> has been upgraded from 1.44 to 1.44_01.
+
+The debugger would cause an assertion failure.
+L<[perl #124127]|https://rt.perl.org/Ticket/Display.html?id=124127>
+
+=back
+
+=head1 Documentation
+
+=head2 Changes to Existing Documentation
+
+=head3 L<perlfunc>
+
+=over 4
+
+=item *
+
+Mention that L<C<study()>|perlfunc/study> is currently a no-op.
+
+=back
+
+=head3 L<perlguts>
+
+=over 4
+
+=item *
+
+The OOK example has been updated to account for COW changes and a change in the
+storage of the offset.
+
+=back
+
+=head3 L<perlhacktips>
+
+=over 4
+
+=item *
+
+Documentation has been added illustrating the perils of assuming the contents
+of static memory pointed to by the return values of Perl wrappers for C library
+functions doesn't change.
+
+=back
+
+=head3 L<perlpodspec>
+
+=over 4
+
+=item *
+
+The specification of the POD language is changing so that the default encoding
+of PODs that aren't in UTF-8 (unless otherwise indicated) is CP1252 instead of
+ISO-8859-1 (Latin1).
+
+=back
+
+=head1 Utility Changes
+
+=head2 L<h2ph>
+
+=over 4
+
+=item *
+
+B<h2ph> now handles hexadecimal constants in the compiler's predefined macro
+definitions, as visible in C<$Config{cppsymbols}>.
+L<[perl #123784]|https://rt.perl.org/Ticket/Display.html?id=123784>
+
+=back
+
+=head1 Testing
+
+=over 4
+
+=item *
+
+F<t/perf/taint.t> has been added to see if optimisations with taint issues are
+keeping things fast.
+
+=item *
+
+F<t/porting/re_context.t> has been added to test that L<utf8> and its
+dependencies only use the subset of the C<$1..$n> capture vars that
+Perl_save_re_context() is hard-coded to localize, because that function has no
+efficient way of determining at runtime what vars to localize.
+
+=back
+
+=head1 Platform Support
+
+=head2 Platform-Specific Notes
+
+=over 4
+
+=item Win32
+
+=over 4
+
+=item *
+
+Previously, when compiling with a 64-bit Visual C++, every Perl XS module
+(including CPAN ones) and Perl aware C file would unconditionally have around a
+dozen warnings from F<hv_func.h>.  These warnings have been silenced.  GCC (all
+bitness) and 32-bit Visual C++ were not affected.
+
+=item *
+
+B<miniperl.exe> is now built with B<-fno-strict-aliasing>, allowing 64-bit
+builds to complete with GCC 4.8.
+L<[perl #123976]|https://rt.perl.org/Ticket/Display.html?id=123976>
+
+=back
+
+=back
+
+=head1 Selected Bug Fixes
+
+=over 4
+
+=item *
+
+Repeated global pattern matches in scalar context on large tainted strings were
+exponentially slow depending on the current match position in the string.
+L<[perl #123202]|https://rt.perl.org/Ticket/Display.html?id=123202>
+
+=item *
+
+The original visible value of L<C<$E<sol>>|perlvar/$E<sol>> is now preserved
+when it is set to an invalid value.  Previously if you set C<$/> to a reference
+to an array, for example, perl would produce a runtime error and not set PL_rs,
+but Perl code that checked C<$/> would see the array reference.
+L<[perl #123218]|https://rt.perl.org/Ticket/Display.html?id=123218>
+
+=item *
+
+Perl 5.14.0 introduced a bug whereby C<eval { LABEL: }> would crash.  This has
+been fixed.
+L<[perl #123652]|https://rt.perl.org/Ticket/Display.html?id=123652>
+
+=item *
+
+Extending an array cloned from a parent thread could result in "Modification of
+a read-only value attempted" errors when attempting to modify the new elements.
+L<[perl #124127]|https://rt.perl.org/Ticket/Display.html?id=124127>
+
+=item *
+
+Several cases of data used to store environment variable contents in core C
+code being potentially overwritten before being used have been fixed.
+L<[perl #123748]|https://rt.perl.org/Ticket/Display.html?id=123748>
+
+=item *
+
+UTF-8 variable names used in array indexes, unquoted UTF-8 HERE-document
+terminators and UTF-8 function names all now work correctly.
+L<[perl #124113]|https://rt.perl.org/Ticket/Display.html?id=124113>
+
+=item *
+
+A subtle bug introduced in Perl 5.20.2 involving UTF-8 in regular expressions
+and sometimes causing a crash has been fixed.  A new test script has been added
+to test this fix; see under L</Testing>.
+L<[perl #124109]|https://rt.perl.org/Ticket/Display.html?id=124109>
+
+=item *
+
+Some patterns starting with C</.*..../> matched against long strings have been
+slow since Perl 5.8, and some of the form C</.*..../i> have been slow since
+Perl 5.18.  They are now all fast again.
+L<[perl #123743]|https://rt.perl.org/Ticket/Display.html?id=123743>
+
+=item *
+
+Warning fatality is now ignored when rewinding the stack.  This prevents
+infinite recursion when the now fatal error also causes rewinding of the stack.
+L<[perl #123398]|https://rt.perl.org/Ticket/Display.html?id=123398>
+
+=item *
+
+C<setpgrp($nonzero)> (with one argument) was accidentally changed in Perl 5.16
+to mean C<setpgrp(0)>.  This has been fixed.
+
+=item *
+
+A crash with C<< %::=(); J->${\"::"} >> has been fixed.
+L<[perl #125541]|https://rt.perl.org/Ticket/Display.html?id=125541>
+
+=item *
+
+Regular expression possessive quantifier Perl 5.20 regression now fixed.
+C<qr/>I<PAT>C<{>I<min>,I<max>C<}+>C</> is supposed to behave identically to
+C<qr/(?E<gt>>I<PAT>C<{>I<min>,I<max>C<})/>.  Since Perl 5.20, this didn't work
+if I<min> and I<max> were equal.
+L<[perl #125825]|https://rt.perl.org/Ticket/Display.html?id=125825>
+
+=item *
+
+Code like C</$a[/> used to read the next line of input and treat it as though
+it came immediately after the opening bracket.  Some invalid code consequently
+would parse and run, but some code caused crashes, so this is now disallowed.
+L<[perl #123712]|https://rt.perl.org/Ticket/Display.html?id=123712>
+
+=back
+
+=head1 Acknowledgements
+
+Perl 5.20.3 represents approximately 7 months of development since Perl 5.20.2
+and contains approximately 3,200 lines of changes across 99 files from 26
+authors.
+
+Excluding auto-generated files, documentation and release tools, there were
+approximately 1,500 lines of changes to 43 .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 5.20.3:
+
+Alex Vandiver, Andy Dougherty, Aristotle Pagaltzis, Chris 'BinGOs' Williams,
+Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell,
+Father Chrysostomos, H.Merijn Brand, James E Keenan, James McCoy, Jarkko
+Hietaniemi, Karen Etheridge, Karl Williamson, kmx, Lajos Veres, Lukas Mai,
+Matthew Horsfall, Petr Písař, Randy Stauner, Ricardo Signes, Sawyer X, Steve
+Hay, Tony Cook, 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 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 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.
+
+=cut