man > perl5161delta(1)

PERL5161DELTA(1)                  Perl Programmers Reference Guide                  PERL5161DELTA(1)

NAME
       perl5161delta - what is new for perl v5.16.1

DESCRIPTION
       This document describes differences between the 5.16.0 release and the 5.16.1 release.

       If you are upgrading from an earlier release such as 5.14.0, first read perl5160delta, which
       describes differences between 5.14.0 and 5.16.0.

Security
   an off-by-two error in Scalar-List-Util has been fixed
       The bugfix was in Scalar-List-Util 1.23_04, and perl 5.16.1 includes Scalar-List-Util 1.25.

Incompatible Changes
       There are no changes intentionally incompatible with 5.16.0 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
       •   Scalar::Util and List::Util have been upgraded from version 1.23 to version 1.25.

       •   B::Deparse  has  been  updated  from version 1.14 to 1.14_01.  An "uninitialized" warning
           emitted by B::Deparse has been squashed [perl #113464].

Configuration and Compilation
       •   Building perl with some Windows compilers used to fail due to a problem  with  miniperl's
           "glob"  operator  (which  uses  the  "perlglob"  program)  deleting  the PATH environment
           variable [perl #113798].

Platform Support
   Platform-Specific Notes
       VMS All C header files from the top-level directory of the distribution are now installed  on
           VMS,  providing  consistency with a long-standing practice on other platforms. Previously
           only a subset were installed, which broke non-core extension builds for  extensions  that
           depended on the missing include files.

Selected Bug Fixes
       •   A  regression  introduced  in Perl v5.16.0 involving "tr/SEARCHLIST/REPLACEMENTLIST/" has
           been fixed.  Only the first instance is supposed to be meaningful if a character  appears
           more  than  once  in  "SEARCHLIST".   Under  some  circumstances,  the final instance was
           overriding all earlier ones.  [perl #113584]

       •   "B::COP::stashlen" has been added.   This provides access to an internal field  added  in
           perl  5.16  under  threaded  builds.   It  was  broken at the last minute before 5.16 was
           released [perl #113034].

       •   The re pragma will no longer clobber $_. [perl #113750]

       •   Unicode 6.1 published  an  incorrect  alias  for  one  of  the  Canonical_Combining_Class
           property's  values  (which range between 0 and 254).  The alias "CCC133" should have been
           "CCC132".  Perl now overrides the data file furnished by  Unicode  to  give  the  correct
           value.

       •   Duplicating scalar filehandles works again.  [perl #113764]

       •   Under  threaded  perls,  a  runtime  code block in a regular expression could corrupt the
           package name stored in the op tree, resulting in bad  reads  in  "caller",  and  possibly
           crashes [perl #113060].

       •   For  efficiency's sake, many operators and built-in functions return the same scalar each
           time.  Lvalue subroutines and subroutines in the  CORE::  namespace  were  allowing  this
           implementation  detail  to  leak through.  "print &CORE::uc("a"), &CORE::uc("b")" used to
           print "BB".  The same thing would happen with an lvalue subroutine returning  the  return
           value of "uc".  Now the value is copied in such cases [perl #113044].

       •   "__SUB__" now works in special blocks ("BEGIN", "END", etc.).

       •   Formats that reference lexical variables from outside no longer result in crashes.

Known Problems
       There  are  no new known problems, but consult "Known Problems" in perl5160delta to see those
       identified in the 5.16.0 release.

Acknowledgements
       Perl 5.16.1 represents approximately 2 months of development since Perl 5.16.0  and  contains
       approximately 14,000 lines of changes across 96 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 5.16.1:

       Chris  'BinGOs' Williams, Craig A. Berry, Father Chrysostomos, Karl Williamson, Paul Johnson,
       Reini Urban, Ricardo Signes, Tony Cook.

       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 http://rt.perl.org/perlbug/ .
       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 AT 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 AT 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 v5.38.2                                 2026-06-12                             PERL5161DELTA(1)