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NAME

perldelta - what is new for perl v5.19.11

DESCRIPTION

This document describes differences between the 5.19.10 release and the 5.19.11 release.

If you are upgrading from an earlier release such as 5.19.9, first read perl51910delta, which describes differences between 5.19.9 and 5.19.10.

Modules and Pragmata

New Modules and Pragmata

  • experimental version 0.007 has been added.

    This pragma provides an easy and convenient way to enable or disable experimental features.

Updated Modules and Pragmata

  • Carp has been upgraded from version 1.33 to 1.3301.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • CPAN has been upgraded from version 2.04-TRIAL to 2.05.

    This fixes local::lib shell variable string output and prevents an endless loop when running "notest test Module" for some Module having dependencies.

  • DB has been upgraded from version 1.43 to 1.44.

    The debugger now correctly restores its input and output filehandles after using the pager command. [perl #121456]

  • ExtUtils::Install has been upgraded from version 1.63 to 1.67.

    When upgrading an already-installed file, ExtUtils::Install could mess up the permissions of files if the old versions of files were hard or symbolic links. This has now been fixed. [perl #72028]

    The MM_TEST_ROOT feature has been removed from the tests.

  • ExtUtils::MakeMaker has been upgraded from version 6.92 to 6.94.

    A regression in MM_Unix.pm has been resolved. [Issue #96]

  • Module::CoreList has been upgraded from version 3.09 to 3.10.

    The list of Perl versions covered has been updated.

  • PerlIO has been upgraded from version 1.08 to 1.09.

    The warning about the use of the :utf8 layer has been made more prominent.

  • Storable has been upgraded from version 2.48 to 2.49.

    Recognition of tied SVs has been tightened up.

  • Win32 has been upgraded from version 0.48 to 0.49.

    This fixes a problem when building with gcc version 4.8.1 from http://www.mingw.org. [cpan #94730]

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

  • The now fatal error message Character following "\c" must be ASCII has been reworded as Character following "\c" must be printable ASCII to emphasize that in \cX, X must be a printable (non-control) ASCII character.

Utility Changes

perlbug

  • perlbug has been modified to supply the report template with CRLF line endings on Windows. [perl #121277]

  • perlbug now makes as few assumptions as possible about the encoding of the report. This will likely change in the future to assume UTF-8 by default but allow a user override.

Configuration and Compilation

  • By default, gcc 4.9 does some optimizations that break perl. The -fwrapv option disables those optimizations (and probably others), so for gcc 4.9 (and later, since the optimizations probably won't go away), Configure now adds -fwrapv unless the user requests -fno-wrapv, which disables -fwrapv, or -fsanitize=undefined, which turns the overflows -fwrapv ignores into runtime errors. (This is not done prior to gcc 4.3, since -fwrapv was broken then.) [perl #121505]

Platform Support

Platform-Specific Notes

VMS

On VMS only, a check for glob metacharacters in a path returned by the glob() operator has been replaced with a check for VMS wildcard characters. This saves a significant number of unnecessary lstat() calls such that some simple glob operations become 60-80% faster.

Win32

The time taken to build perl on Windows has been reduced quite significantly (time savings in the region of 30-40% are typically seen) by reducing the number of, usually failing, I/O calls for each require() (for miniperl.exe only). [perl #121119]

About 15 minutes of idle sleeping was removed from running make test due to a bug in which the timeout monitor used for tests could not be cancelled once the test completes, and the full timeout period elapsed before running the next test file. [perl #121395]

On a perl built without pseudo-fork (pseudo-fork builds were not affected by this bug), killing a process tree with kill() and a negative signal resulted in kill() inverting the returned value. For example, if kill() killed 1 process tree PID then it returned 0 instead of 1, and if kill() was passed 2 invalid PIDs then it returned 2 instead of 0. This has probably been the case since the process tree kill feature was implemented on Win32. It has now been corrected to follow the documented behaviour. [perl #121230]

When building a 64-bit perl, an uninitialized memory read in miniperl.exe, used during the build process, could lead to a 4GB wperl.exe being created. This has now been fixed. (Note that perl.exe itself was unaffected, but obviously wperl.exe would have been completely broken.) [perl #121471]

Perl can now be built with gcc version 4.8.1 from http://www.mingw.org. This was previously broken due to an incorrect definition of DllMain() in one of perl's source files. Earlier gcc versions were also affected when using version 4 of the w32api package. Versions of gcc available from http://mingw-w64.sourceforge.net/ were not affected. [perl #121643]

The test harness now has no failures when perl is built on a FAT drive with the Windows OS on an NTFS drive. [perl #21442]

Internal Changes

  • LC_NUMERIC is now initialized to the C locale. This affects only XS modules, as the Perl core usages always make sure this locale category is correctly set for their purposes. XS code remains vulnerable to other code changing this category's locale. Further fixes are planned in Perl 5.22 to reduce these long-standing vulnerabilities. [perl #121317]

Selected Bug Fixes

  • A regression involving the string value of $! introduced in Perl 5.19.2 has been reverted for Perl 5.20. [perl #119499]

    This re-breaks the bugs it fixed, perl #112208, so an alternative fix is planned for Perl 5.22

  • A regression was introduced in Perl 5.19.10 that under some circumstances caused //m matches to falsely fail. Now fixed. [perl #121484]

  • A regression was introduced in the fix for perl #116192 that prevented perl -I /somedir/ (with a trailing slash) from finding .pmc files. This has been fixed. [perl #121512].

  • Fixed a bug detected by valgrind where sv_pvn_force_flags() would check SvPVX() even when the SV hadn't been upgraded to a SVt_PV. SvPVX() is only initialized when the SV is upgraded to a SVt_PV or higher. [perl #121366]

  • Fixed a bug in caller() introduced in Perl 5.18.0. In some circumstances when caller() was called on an eval STRING stack frame it would attempt to allocate the limit of the address space minus one, which would croak with an out of memory error, which would be caught by the eval. A change in Perl 5.19.1 which increased allocation sizes to allow COW to operate more often rounded that allocation size up and wrapped to a zero allocation size, resulting in a crash when the source string was copied over. [perl #120998].

Known Problems

Acknowledgements

Perl 5.19.11 represents approximately 4 weeks of development since Perl 5.19.10 and contains approximately 3,600 lines of changes across 140 files from 18 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 850 lines of changes to 72 .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 5.19.11:

Aaron Crane, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, David Golden, David Mitchell, H.Merijn Brand, Hiroo Hayashi, Karl Williamson, Matthew Horsfall, Ricardo Signes, Shirakata Kentaro, Smylers, Steve Hay, Thomas Sibley, Tony Cook, Zefram, Ævar Arnfjörð Bjarmason.

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.

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.