perl5134delta


DESCRIPTION
       This document describes differences between the 5.13.4 release and the
       5.13.3 release.

       If you are upgrading from an earlier release such as 5.13.2, first read
       perl5133delta, which describes differences between 5.13.2 and 5.13.3.

Core Enhancements
   "srand()" now returns the seed
       This allows programs that need to have repeatable results to not have
       to come up with their own seed generating mechanism.  Instead, they can
       use "srand()" and somehow stash the return for future use.  Typical is
       a test program which has too many combinations to test comprehensively
       in the time available to it each run.  It can test a random subset each
       time, and should there be a failure, log the seed used for that run so
       that it can later be used to reproduce the exact results.

   "\N{name}" and "charnames" enhancements
       "\N{}", "charnames::vianame", "charnames::viacode" now know about every
       character in Unicode.  Previously, they didn't know about the Hangul
       syllables nor a number of CJK (Chinese/Japanese/Korean) characters.

Incompatible Changes
   Declare API incompatibility between blead releases
       Only stable releases (5.10.x, 5.12.x, 5.14.x, ...) guarantee binary
       compatibility with each other, while blead releases (5.13.x, 5.15.x,
       ...) often break this compatibility. However, prior to perl 5.13.4, all
       blead releases had the same "PERL_API_REVISION", "PERL_API_VERSION",
       and "PERL_API_SUBVERSION", effectively declaring them as binary
       compatible, which they weren't. From now on, blead releases will have a
       "PERL_API_SUBVERSION" equal to their "PERL_SUBVERSION", explicitly
       marking them as incompatible with each other.

       Maintenance releases of stable perl versions will continue to make no
       intentionally incompatible API changes.

   Check API compatibility when loading XS modules
       When perl's API changes in incompatible ways (which usually happens
       between every major release), XS modules compiled for previous versions
       of perl will not work anymore. They will need to be recompiled against
       the new perl.

       In order to ensure that modules are recompiled, and to prevent users
       from accidentally loading modules compiled for old perls into newer
       ones, the "XS_APIVERSION_BOOTCHECK" macro has been added. That macro,
       which is called when loading every newly compiled extension, compares
       the API version of the running perl with the version a module has been
       compiled for and raises an exception if they don't match.

   Binary Incompatible with all previous Perls
       Some bit fields have been reordered; therefore, this release will not
       be binary compatible with any previous Perl release.

       o   ";*"

       o   ";\sigil"

       o   ";\[...]"

       Due to this bug fix, functions using the "(*)", "(;$)" and "(;*)"
       prototypes are parsed with higher precedence than before. So in the
       following example:

         sub foo($);
         foo $a < $b;

       the second line is now parsed correctly as "foo($a) < $b", rather than
       "foo($a < $b)". This happens when one of these operators is used in an
       unparenthesised argument:

         < > <= >= lt gt le ge
         == != <=> eq ne cmp ~~
         &
         | ^
         &&
         || //
         .. ...
         ?:
         = += -= *= etc.

Deprecations
   List assignment to $[
       After assignment to $[ has been deprecated and started to give warnings
       in perl version 5.12.0, this version of perl also starts to emit a
       warning when assigning to $[ in list context. This fixes an oversight
       in 5.12.0.

Performance Enhancements
       o   Make string appending 100 times faster

           When doing a lot of string appending, perl could end up allocating
           a lot more memory than needed in a very inefficient way, if perl
           was configured to use the system's "malloc" implementation instead
           of its own.

           "sv_grow", which is what's being used to allocate more memory if
           necessary when appending to a string, has now been taught how to
           round up the memory it requests to a certain geometric progression,
           making it much faster on certain platforms and configurations. On
           Win32, it's now about 100 times faster.

       o   For weak references, the common case of just a single weak
           reference per referent has been optimised to reduce the storage
           required. In this case it saves the equivalent of one small perl
           array per referent.

       o   "XPV", "XPVIV", and "XPVNV" now only allocate the parts of the "SV"
           Windows, allowing those archives to be uploaded to CPAN.

       "B::Lint"
           Upgraded from version 1.11 to 1.12.

       "Carp"
           Upgraded from version 1.16 to 1.18.

           Carp now detects incomplete caller() overrides and avoids using
           bogus @DB::args. To provide backtraces, Carp relies on particular
           behaviour of the caller built-in. Carp now detects if other code
           has overridden this with an incomplete implementation, and modifies
           its backtrace accordingly. Previously incomplete overrides would
           cause incorrect values in backtraces (best case), or obscure fatal
           errors (worst case)

           This fixes certain cases of "Bizarre copy of ARRAY" caused by
           modules overriding "caller()" incorrectly.

       "Compress::Raw::Bzip2"
           Upgraded from version 2.027 to 2.030.

       "Compress::Raw::Zlib"
           Upgraded from version 2.027 to 2.030.

       "File::Spec"
           Upgraded from version 3.31 to 3.31_01.

           Various issues in File::Spec::VMS have been fixed.

       "I18N::Langinfo"
           Upgraded from version 0.03 to 0.04.

           "langinfo()" now defaults to using $_ if there is no argument
           given, just like the documentation always claimed it did.

       "IO::Compress"
           Upgraded from version 2.027 to 2.030.

       "Module::CoreList"
           Upgraded from version 2.36 to 2.37.

           Besides listing the updated core modules of this release, it also
           stops listing the "Filespec" module. That module never existed in
           core. The scripts generating "Module::CoreList" confused it with
           "VMS::Filespec", which actually is a core module, since the time of
           perl 5.8.7.

       "Test::Harness"
           Upgraded from version 3.21 to 3.22.

       "Test::Simple"
           Upgraded from version 0.94 to 0.96.

   Removed Modules and Pragmata
       This release does not remove any modules or pragmata.

Documentation
   Changes to Existing Documentation
       perldiag

       o   The following existing diagnostics are now documented:

           o   Ambiguous use of %c resolved as operator %c

           o   Ambiguous use of %c{%s} resolved to %c%s

           o   Ambiguous use of %c{%s%s} resolved to %c%s%s

           o   Ambiguous use of -%s resolved as -&%s()

           o   Invalid strict version format (%s)

           o   Invalid version format (%s)

           o   Invalid version object

       perlport

       o   Documented a limitation of alarm() on Win32.

       perlre

       o   Minor fix to a multiple scalar match example.

Configuration and Compilation
       o   Compatibility with "C++" compilers has been improved.

       o   On compilers that support it, "-Wwrite-strings" is now added to
           cflags by default.

Testing
       o   t/op/print.t has been added to test implicit printing of $_.

       o   t/io/errnosig.t has been added to test for restoration of of $!
           when leaving signal handlers.

       o   t/op/tie_fetch_count.t has been added to see if "FETCH" is only
           called once on tied variables.

       o   lib/Tie/ExtraHash.t has been added to make sure the, previously
           untested, Tie::ExtraHash keeps working.

       o   t/re/overload.t has been added to test against string corruption in
           pattern matches on overloaded objects. This is a TODO test.

Platform Support
   Platform-Specific Notes
           The option to define "PERL_POLLUTE" to expose older 5.005 symbols
           for backwards compatibility has been removed. It's use was always
           discouraged, and MakeMaker contains a more specific escape hatch:

               perl Makefile.PL POLLUTE=1

           This can be used for modules that have not been upgraded to 5.6
           naming conventions (and really should be completely obsolete by
           now).

       Added "PERL_STATIC_INLINE"
           The "PERL_STATIC_INLINE" define has been added to provide the best-
           guess incantation to use for static inline functions, if the C
           compiler supports C99-style static inline. If it doesn't, it'll
           give a plain "static".

           "HAS_STATIC_INLINE" can be used to check if the compiler actually
           supports inline functions.

Selected Bug Fixes
       o   A possible memory leak when using caller() to set @DB::args has
           been fixed.

       o   Several memory leaks when loading XS modules were fixed.

       o   A panic in the regular expression optimizer has been fixed
           (RT#75762).

       o   Assignments to lvalue subroutines now honor copy-on-write behavior
           again, which has been broken since version 5.10.0 (RT#75656).

       o   Assignments to glob copies now behave just like assignments to
           regular globs (RT#1804).

       o   Within signal handlers, $! is now implicitly localized.

       o   readline now honors "<>" overloading on tied arguments.

       o   substr(), pos(), keys(), and vec() could, when used in combination
           with lvalues, result in leaking the scalar value they operate on,
           and cause its destruction to happen too late. This has now been
           fixed.

       o   Building with "PERL_GLOBAL_STRUCT", which has been broken
           accidentally in 5.13.3, now works again.

Known Problems
       o   The changes in substr() broke "HTML::Parser" <= 3.66. A fixed
           "HTML::Parser" is available as version 3.67 on CPAN.

       o   The changes in prototype handling break "Switch". A patch has been
           sent upstream and will hopefully appear on CPAN soon.

Acknowledgements
       Rafael Garcia-Suarez, Reini Urban, Robin Barker, Slaven Rezic, Steve
       Peters, Tony Cook, Wolfram Humann, Zefram

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@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 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 v5.14.2                      2011-09-26                  PERL5134DELTA(1)
Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2017 Hurricane Electric. All Rights Reserved.