Ubuntu Manpage: perl5203delta - what is new for perl v5.20.3

Provided by: perl-doc_5.38.2-3.2ubuntu0.1_all

NAME

       perl5203delta - what is new for perl v5.20.3

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 perl5202delta, which describes
       differences between 5.20.1 and 5.20.2.

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 "Reporting Bugs" below.

Modules and Pragmata

   Updated Modules and Pragmata
       •   Errno has been upgraded from version 1.20_05 to 1.20_06.

           Add -P to the pre-processor command-line on GCC 5.  GCC added extra line directives, breaking parsing
           of error code definitions.  [GH #14491] <https://github.com/Perl/perl5/issues/14491>

       •   Module::CoreList has been upgraded from version 5.20150214 to 5.20150822.

           Updated to cover the latest releases of Perl.

       •   perl5db.pl has been upgraded from 1.44 to 1.44_01.

           The       debugger       would      cause      an      assertion      failure.       [GH      #14605]
           <https://github.com/Perl/perl5/issues/14605>

Documentation

   Changes to Existing Documentation
       perlfunc

       •   Mention that study() is currently a no-op.

       perlguts

       •   The OOK example has been updated to account for COW changes and  a  change  in  the  storage  of  the
           offset.

       perlhacktips

       •   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.

       perlpodspec

       •   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).

Utility Changes

   h2ph
       •   h2ph now handles hexadecimal constants in the compiler's predefined macro definitions, as visible  in
           $Config{cppsymbols}.  [GH #14491] <https://github.com/Perl/perl5/issues/14491>

Testing

       •   t/perf/taint.t has been added to see if optimisations with taint issues are keeping things fast.

       •   t/porting/re_context.t  has  been added to test that utf8 and its dependencies only use the subset of
           the "$1..$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.

Platform Support

   Platform-Specific Notes
       Win32
           •   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  hv_func.h.   These
               warnings have been silenced.  GCC (all bitness) and 32-bit Visual C++ were not affected.

           •   miniperl.exe  is now built with -fno-strict-aliasing, allowing 64-bit builds to complete with GCC
               4.8.  [GH #14556] <https://github.com/Perl/perl5/issues/14556>

Selected Bug Fixes

       •   Repeated global pattern matches in scalar context on large tainted strings  were  exponentially  slow
           depending     on     the     current     match    position    in    the    string.     [GH    #14238]
           <https://github.com/Perl/perl5/issues/14238>

       •   The original visible value of $/ is now preserved when it is set to an invalid value.  Previously  if
           you  set  $/  to a reference to an array, for example, perl would produce a runtime error and not set
           PL_rs,  but  Perl  code  that  checked   $/   would   see   the   array   reference.    [GH   #14245]
           <https://github.com/Perl/perl5/issues/14245>

       •   Perl  5.14.0  introduced  a  bug  whereby  "eval  { LABEL: }" would crash.  This has been fixed.  [GH
           #14438] <https://github.com/Perl/perl5/issues/14438>

       •   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.    [GH   #14605]
           <https://github.com/Perl/perl5/issues/14605>

       •   Several cases of data used to store environment variable contents in core C  code  being  potentially
           overwritten       before       being      used      have      been      fixed.       [GH      #14476]
           <https://github.com/Perl/perl5/issues/14476>

       •   UTF-8 variable names used in array  indexes,  unquoted  UTF-8  HERE-document  terminators  and  UTF-8
           function names all now work correctly.  [GH #14601] <https://github.com/Perl/perl5/issues/14601>

       •   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 "Testing".  [GH
           #14600] <https://github.com/Perl/perl5/issues/14600>

       •   Some patterns starting with "/.*..../" matched against long strings have been slow  since  Perl  5.8,
           and  some  of the form "/.*..../i" have been slow since Perl 5.18.  They are now all fast again.  [GH
           #14475] <https://github.com/Perl/perl5/issues/14475>

       •   Warning fatality is now ignored when rewinding the stack.  This prevents infinite recursion when  the
           now     fatal     error     also     causes     rewinding     of     the    stack.     [GH    #14319]
           <https://github.com/Perl/perl5/issues/14319>

       •   setpgrp($nonzero) (with one argument) was accidentally changed in Perl 5.16 to mean setpgrp(0).  This
           has been fixed.

       •   A     crash     with     "%::=();     J->${\"::"}"     has     been     fixed.       [GH      #14790]
           <https://github.com/Perl/perl5/issues/14790>

       •   Regular  expression  possessive quantifier Perl 5.20 regression now fixed.  "qr/"PAT"{"min,max"}+""/"
           is supposed to behave identically to "qr/(?>"PAT"{"min,max"})/".  Since Perl 5.20, this  didn't  work
           if min and max were equal.  [GH #14857] <https://github.com/Perl/perl5/issues/14857>

       •   Code  like  "/$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.  [GH #14462] <https://github.com/Perl/perl5/issues/14462>

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 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.