perl5124delta - what is new for perl v5.12.4


   This document describes differences between the 5.12.3 release and the
   5.12.4 release.

   If you are upgrading from an earlier release such as 5.12.2, first read
   perl5123delta, which describes differences between 5.12.2 and 5.12.3.
   The major changes made in 5.12.0 are described in perl5120delta.

Incompatible Changes

   There are no changes intentionally incompatible with 5.12.3. If any
   exist, they are bugs and reports are welcome.

Selected Bug Fixes

   When strict "refs" mode is off, "%{...}" in rvalue context returns
   "undef" if its argument is undefined.  An optimisation introduced in
   Perl 5.12.0 to make "keys %{...}" faster when used as a boolean did not
   take this into account, causing "keys %{+undef}" (and "keys %$foo" when
   $foo is undefined) to be an error, which it should be so in strict mode
   only [perl #81750].

   "lc", "uc", "lcfirst", and "ucfirst" no longer return untainted strings
   when the argument is tainted. This has been broken since perl 5.8.9
   [perl #87336].

   Fixed a case where it was possible that a freed buffer may have been
   read from when parsing a here document.

Modules and Pragmata

   Module::CoreList has been upgraded from version 2.43 to 2.50.


   The cpan/CGI/t/http.t test script has been fixed to work when the
   environment has HTTPS_* environment variables, such as HTTPS_PROXY.


   Updated the documentation for rand() in perlfunc to note that it is not
   cryptographically secure.

Platform Specific Notes

       Support Ubuntu 11.04's new multi-arch library layout.


   Perl 5.12.4 represents approximately 5 months of development since Perl
   5.12.3 and contains approximately 200 lines of changes across 11 files
   from 8 authors.

   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 5.12.4:

   Andy Dougherty, David Golden, David Leadbeater, Father Chrysostomos,
   Florian Ragwitz, Jesse Vincent, Leon Brocard, Zsbn Ambrus.

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 .  There may also be
   information at , 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 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 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.


   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.


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