perl5173delta - what is new for perl v5.17.3
This document describes differences between the 5.17.2 release and the 5.17.3 release.
If you are upgrading from an earlier release such as 5.17.1, first read perl5172delta, which describes differences between 5.17.1 and 5.17.2.
The loop controls next,
last and redo,
and the special dump operator,
now allow arbitrary expressions to be used to compute labels at run time.
Previously,
any argument that was not a constant was treated as the empty string.
$ENV{foo}=undef deletes value from environ,
like delete $ENV{foo}This facilitates use of local() with %ENV entries.
In previous versions of Perl,
undef was converted to the empty string.
A value stored in an environment variable has always been stringified.
In this release,
it is converted to be only a byte string.
First,
it is forced to be a only a string.
Then if the string is utf8 and the equivalent of utf8::downgrade() works,
that result is used; otherwise,
the equivalent of utf8::encode() is used,
and a warning is issued about wide characters ("Diagnostics").
given now aliases the global $_Instead of assigning to an implicit lexical $_,
given now makes the global $_ an alias for its argument,
just like foreach.
However,
it still uses lexical $_ if there is lexical $_ in scope (again,
just like foreach) [perl #114020].
CVf_* and GVf_* and more SV-related flag values are now provided as constants in the B:: namespace and available for export.
The default export list has not changed.-nobanner option has been fixed,
and formats can now be dumped.
When passed a sub name to dump,
it will check also to see whether it is the name of a format.
If a sub and a format share the same name,
it will dump both.B::PADLIST,
which will be added in Perl 5.17.4.format line are also now deparsed correctly.startform() or start_form(),
and bogus "Insecure Dependency" warnings appearing with some versions of perl are now worked around.compress(),
uncompress(),
memGzip() and memGunzip() have been speeded up by making parameter validation more efficient.$VERSIONs have been suppressed.codes_in_verbatim option is now disabled by default.
See cpan/Pod-Simple/ChangeLog for the full details./[s]/ or /[s]/i are now optimized as if they did not have the brackets,
i.e.
/s/ or /s/i.getservbyname(),
setlogsock()and log levels in syslog(),
together with fixes for Windows,
Haiku-OS and GNU/kFreeBSD.
See cpan/Sys-Syslog/Changes for the full details.timegm() and timelocal() to croak.dump,
goto,
next,
last and redo) have always had the same precedence as assignment operators,
but this was not documented until now.$_ warning against the use of lexical $_ [perl #114020].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.
This message now occurs when a here document label has an initial quotation mark but the final quotation mark is missing.
This replaces a bogus and misleading error message about not finding the label itself [perl #114104].
This error is thrown when a child pseudo-process in the ithreads implementation on Windows was not scheduled within the time period allowed and therefore was not able to initialize properly [perl #88840].
Attempts to put wide characters into environment variables via %ENV now provoke this warning.
Support code relating to UTS global has been removed. UTS was a mainframe version of System V created by Amdahl, subsequently sold to UTS Global. The port has not been touched since before Perl 5.8.0, and UTS Global is now defunct.
A new makefile option, USE_64_BIT_INT, has been added to the Windows makefiles. Set this to "define" when building a 32-bit perl if you want it to use 64-bit integers.
Machine code size reductions, already made to the DLLs of XS modules in Perl 5.17.2, have now been extended to the perl DLL itself.
Building with VC++ 6.0 was inadvertently broken in Perl 5.17.2 but has now been fixed again.
The a2p build has been fixed for the HP C++ compiler on OpenVMS.
\w now matches the code points U+200C (ZERO WIDTH NON-JOINER) and U+200D (ZERO WIDTH JOINER).
\W no longer matches these.
This change is because Unicode corrected their definition of what \w should match.dump LABEL no longer leaks its label.stat() and truncate() that can take either filenames or handles.
stat 1 ?
foo : bar nows treats its argument as a file name (since it is an arbitrary expression),
rather than the handle "foo".truncate FOO,
$len no longer falls back to treating "FOO" as a file name if the filehandle has been deleted.
This was broken in Perl 5.16.0.s/// now turns vstrings into plain strings when performing a substitution,
even if the resulting string is the same (s/a/a/).undef on a subroutine now clears call checkers.ref operator started leaking memory on blessed objects in Perl 5.16.0.
This has been fixed [perl #114340].use no longer tries to parse its arguments as a statement,
making use constant { () }; a syntax error [perl #114222].use statements are now permitted inside formats.print $x and sub { print $x }->() now always produce the same output.
It was possible for the latter to refuse to close over $x if the variable was not active; e.g.,
if it was defined outside a currently-running named subroutine.print $x and print eval '$x' now produce the same output.
This also allows "my $x if 0" variables to be seen in the debugger [perl #114018].= and .),
but only sometimes.
Semicolons and low-precedence operators in format argument lines no longer confuse the parser into ignoring the line's return value.
In format argument lines,
braces can now be used for anonymous hashes,
instead of being treated always as do blocks./(?{...})/ and qq/${...}/) [perl #114040].require() could potentially read one or two bytes before the start of the filename for filenames less than three bytes long and ending /\.p?\z/.
This has now been fixed.
Note that it could never have happened with module names given to use() or require() anyway.require() has been made thread-safe on VMS.re_compile() API function,
the entry point for perl's regex compiler,
was accidentally changed in Perl 5.17.1 to operate on the current engine.
This has now been restored to its former core-engine-specific state [perl #114302]./$unchanging/).
This has now been fixed./(?{})/ expression which affected the TryCatch test suite has been fixed [perl #114242].Perl 5.17.3 represents approximately 4 weeks of development since Perl 5.17.2 and contains approximately 85,000 lines of changes across 470 files from 24 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 5.17.3:
Andy Dougherty, Chip Salzenberg, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, Dave Rolsky, David Leadbeater, David Mitchell, Eric Brine, Father Chrysostomos, Goro Fuji, James E Keenan, Jan Dubois, Joaquin Ferrero, Karl Williamson, Nicholas Clark, Paul Marquess, Reini Urban, Ricardo Signes, Robin Barker, Shirakata Kentaro, Steffen Müller, Steve Hay, 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.
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@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.
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.
