Ubuntu Manpage: perl5201delta - what is new for perl v5.20.1

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

NAME

       perl5201delta - what is new for perl v5.20.1

DESCRIPTION

       This document describes differences between the 5.20.0 release and the 5.20.1 release.

       If you are upgrading from an earlier release such as 5.18.0, first read perl5200delta, which describes
       differences between 5.18.0 and 5.20.0.

Incompatible Changes

       There are no changes intentionally incompatible with 5.20.0.  If any exist, they are bugs, and we request
       that you submit a report.  See "Reporting Bugs" below.

Performance Enhancements

       •   An  optimization  to  avoid  problems  with  COW and deliberately overallocated PVs has been disabled
           because it interfered with  another,  more  important,  optimization,  causing  a  slowdown  on  some
           platforms.  [GH #13878] <https://github.com/Perl/perl5/issues/13878>

       •   Returning  a  string  from  a lexical variable could be slow in some cases.  This has now been fixed.
           [GH #13880] <https://github.com/Perl/perl5/issues/13880>

Modules and Pragmata

Updated Modules and Pragmata
• Config::Perl::V has been upgraded from version 0.20 to 0.22.

The list of Perl versions covered has been updated and some flaws in the parsing have been fixed.

• Exporter has been upgraded from version 5.70 to 5.71.

Illegal POD syntax in the documentation has been corrected.

• ExtUtils::CBuilder has been upgraded from version 0.280216 to 0.280217.

Android builds now link to both -lperl and $Config::Config{perllibs}.

• File::Copy has been upgraded from version 2.29 to 2.30.

The documentation now notes that "copy" will not overwrite read-only files.

• Module::CoreList has been upgraded from version 3.11 to 5.020001.

The list of Perl versions covered has been updated.

• The PathTools module collection has been upgraded from version 3.47 to 3.48.

Fallbacks are now in place when cross-compiling for Android and $Config::Config{sh} is not yet
defined. [GH #13872] <https://github.com/Perl/perl5/issues/13872>

• PerlIO::via has been upgraded from version 0.14 to 0.15.

A minor portability improvement has been made to the XS implementation.

• Unicode::UCD has been upgraded from version 0.57 to 0.58.

The documentation includes many clarifications and fixes.

• utf8 has been upgraded from version 1.13 to 1.13_01.

The documentation has some minor formatting improvements.

• version has been upgraded from version 0.9908 to 0.9909.

External libraries and Perl may have different ideas of what the locale is. This is problematic when
parsing version strings if the locale's numeric separator has been changed. Version parsing has been
patched to ensure it handles the locales correctly. [GH #13863]
<https://github.com/Perl/perl5/issues/13863>

Documentation

Changes to Existing Documentation
perlapi

• "av_len" - Emphasize that this returns the highest index in the array, not the size of the array.
[GH #13377] <https://github.com/Perl/perl5/issues/13377>

• Note that "SvSetSV" doesn't do set magic.

• "sv_usepvn_flags" - Fix documentation to mention the use of "NewX" instead of "malloc". [GH #13835]
<https://github.com/Perl/perl5/issues/13835>

• Clarify where "NUL" may be embedded or is required to terminate a string.

perlfunc

• Clarify the meaning of "-B" and "-T".

• "-l" now notes that it will return false if symlinks aren't supported by the file system. [GH
#13695] <https://github.com/Perl/perl5/issues/13695>

• Note that "each", "keys" and "values" may produce different orderings for tied hashes compared to
other perl hashes. [GH #13650] <https://github.com/Perl/perl5/issues/13650>

• Note that "exec LIST" and "system LIST" may fall back to the shell on Win32. Only "exec PROGRAM
LIST" and "system PROGRAM LIST" indirect object syntax will reliably avoid using the shell. This has
also been noted in perlport. [GH #13907] <https://github.com/Perl/perl5/issues/13907>

• Clarify the meaning of "our". [GH #13938] <https://github.com/Perl/perl5/issues/13938>

perlguts

• Explain various ways of modifying an existing SV's buffer. [GH #12813]
<https://github.com/Perl/perl5/issues/12813>

perlpolicy

• We now have a code of conduct for the p5p mailing list, as documented in "STANDARDS OF CONDUCT" in
perlpolicy.

perlre

• The "/x" modifier has been clarified to note that comments cannot be continued onto the next line by
escaping them.

perlsyn

• Mention the use of empty conditionals in "for"/"while" loops for infinite loops.

perlxs

• Added a discussion of locale issues in XS code.

Diagnostics

       The following additions or changes have been made to diagnostic  output,  including  warnings  and  fatal
       error messages.  For the complete list of diagnostic messages, see perldiag.

   Changes to Existing Diagnostics
       •   Variable length lookbehind not implemented in regex m/%s/

           Information about Unicode behaviour has been added.

Configuration and Compilation

       •   Building  Perl  no  longer  writes  to  the source tree when configured with Configure's -Dmksymlinks
           option.  [GH #13712] <https://github.com/Perl/perl5/issues/13712>

Platform Support

   Platform-Specific Notes
       Android
           Build support has been improved for cross-compiling in general and for Android in particular.

       OpenBSD
           Corrected architectures and version numbers used in configuration hints when building Perl.

       Solaris
           c99 options have been cleaned up, hints look for solstudio as  well  as  SUNWspro,  and  support  for
           native "setenv" has been added.

       VMS An old bug in feature checking, mainly affecting pre-7.3 systems, has been fixed.

       Windows
           %I64d is now being used instead of %lld for MinGW.

Internal Changes

       •   Added  "sync_locale"  in  perlapi.   Changing  the  program's  locale  should  be avoided by XS code.
           Nevertheless, certain non-Perl libraries called from XS, such as "Gtk" do  so.   When  this  happens,
           Perl  needs  to be told that the locale has changed.  Use this function to do so, before returning to
           Perl.

Selected Bug Fixes

       •   A bug has been fixed where zero-length assertions and code blocks inside of a regex could cause "pos"
           to see an incorrect value.  [GH #14016] <https://github.com/Perl/perl5/issues/14016>

       •   Using "s///e" on tainted utf8 strings could issue bogus "Malformed UTF-8 character (unexpected end of
           string)"      warnings.       This      has      now       been       fixed.        [GH       #13948]
           <https://github.com/Perl/perl5/issues/13948>

       •   "system" and friends should now work properly on more Android builds.

           Due  to  an oversight, the value specified through -Dtargetsh to Configure would end up being ignored
           by some of the build process.  This caused perls cross-compiled for Android to end up with  defective
           versions  of "system", "exec" and backticks: the commands would end up looking for /bin/sh instead of
           /system/bin/sh, and so would fail for the vast majority of devices, leaving $! as "ENOENT".

       •   Many issues have been detected by Coverity <http://www.coverity.com/> and fixed.

Acknowledgements

Perl 5.20.1 represents approximately 4 months of development since Perl 5.20.0 and contains approximately
12,000 lines of changes across 170 files from 36 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 2,600 lines of
changes to 110 .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 5.20.1:

Aaron Crane, Abigail, Alberto Simões, Alexandr Ciornii, Alexandre (Midnite) Jousset, Andrew Fresh, Andy
Dougherty, Brian Fraser, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, David Golden, David
Mitchell, H.Merijn Brand, James E Keenan, Jan Dubois, Jarkko Hietaniemi, John Peacock, kafka, Karen
Etheridge, Karl Williamson, Lukas Mai, Matthew Horsfall, Michael Bunk, Peter Martini, Rafael Garcia-
Suarez, Reini Urban, Ricardo Signes, Shirakata Kentaro, Smylers, Steve Hay, Thomas Sibley, Todd Rinaldo,
Tony Cook, Vladimir Marek, 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.