perl5135delta - what is new for perl v5.13.5
This document describes differences between the 5.13.4 release and the 5.13.5 release.
If you are upgrading from an earlier release such as 5.13.3, first readperl5134delta, which describes differences between 5.13.3 and 5.13.4.
Previously, in code such as
use constant DEBUG => 0;sub GAK { warn if DEBUG; print "stuff\n";}the ops forwarn if DEBUG; would be folded to anull op (ex-const), but thenextstate op would remain, resulting in a runtime op dispatch ofnextstate,nextstate, ...
The execution of a sequence ofnextstate ops is indistinguishable from just the lastnextstate op so the peephole optimizer now eliminates the first of a pair ofnextstate ops, except where the first carries a label, since labels must not be eliminated by the optimizer and label usage isn't conclusively known at compile time.
Theparse_fullstmt function has been added to allow parsing of a single complete Perl statement. Seeperlapi for details.
A new C API for introspecting the hinthash%^H at runtime has been added. Seecop_hints_2hv,cop_hints_fetchpvn,cop_hints_fetchpvs,cop_hints_fetchsv, andhv_copy_hints_hv inperlapi for details.
caller()Thecaller_cx function has been added as an XSUB-writer's equivalent ofcaller(). Seeperlapi for details.
In previous versions of Perl, magic variables like$!,%SIG, etc. would 'leak' into other packages. So%foo::SIG could be used to access signals,${"foo::!"} (with strict mode off) to access C'serrno, etc.
This was a bug, or an 'unintentional' feature, which caused various ill effects, such as signal handlers being wiped when modules were loaded, etc.
This has been fixed (or the feature has been removed, depending on how you see it).
Previously, the following code resulted in a successful match:
my @a = qw(a y0 z);my @b = qw(a x0 z);@a[0 .. $#b] ~~ @b;This odd behaviour has now been fixed[perl #77468].
The first argument of the C API functionPerl_fetch_cop_label has changed fromstruct refcounted he * toCOP *, to better insulate the user from implementation details.
This API function was marked as "may change", and likely isn't in use outside the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other references to it.)
Historically the parser fooled itself into thinking thatqw(...) literals were always enclosed in parentheses, and as a result you could sometimes omit parentheses around them:
for $x qw(a b c) { ... }The parser no longer lies to itself in this way. Wrap the list literal in parentheses, like:
for $x (qw(a b c)) { ... }Scalars containing regular expressions now only allocate the part of theSV body they actually use, saving some space.
Compiling regular expressions has been made faster for the case where upgrading the regex to utf8 is necessary but that isn't known when the compilation begins.
bignumUpgraded from version 0.23 to 0.25.
blibUpgraded from version 1.05 to 1.06.
openUpgraded from version 1.07 to 1.08.
threads-sharedUpgraded from version 1.33_02 to 1.33_03.
warnings andwarnings::registerUpgraded from version 1.10 to 1.11 and from version 1.01 to 1.02 respectively.
It is now possible to register warning categories other than the names of packages usingwarnings::register. Seeperllexwarn for more information.
B::DebugUpgraded from version 1.12 to 1.16.
CPANPLUS::Dist::BuildUpgraded from version 0.46 to 0.48.
Data::DumperUpgraded from version 2.126 to 2.128.
This fixes a crash when using custom sort functions that might cause the stack to change.
EncodeUpgraded from version 2.39 to 2.40.
ErrnoUpgraded from version 1.12 to 1.13.
On some platforms with unusual header files, like Win32/gcc using mingw64 headers, some constants which weren't actually error numbers have been exposed byErrno. This has been fixed[perl #77416].
ExtUtils::MakeMakerUpgraded from version 6.5601 to 6.57_05.
Filter::SimpleUpgraded from version 0.84 to 0.85.
Hash::UtilUpgraded from version 0.08 to 0.09.
Math::BigIntUpgraded from version 1.89_01 to 1.95.
This fixes, among other things, incorrect results when computing binomial coefficients[perl #77640].
Math::BigInt::FastCalcUpgraded from version 0.19 to 0.22.
Math::BigRatUpgraded from version 0.24 to 0.26.
Module::CoreListUpgraded from version 2.37 to 2.38.
PerlIO::scalarUpgraded from version 0.08 to 0.09.
POSIXUpgraded from version 1.19 to 1.20.
It now includes constants for POSIX signal constants.
SafeUpgraded from version 2.27 to 2.28.
This fixes a possible infinite loop when looking for coderefs.
Test::SimpleUpgraded from version 0.96 to 0.97_01.
Tie::HashUpgraded from version 1.03 to 1.04.
CallingTie::Hash->TIEHASH() used to loop forever. Now itcroaks.
Unicode::CollateUpgraded from version 0.56 to 0.59.
XSLoaderUpgraded from version 0.10 to 0.11.
Many of the optree construction functions are now documented.
Expanded to cover many more popular books.
perlfaq,perlfaq2,perlfaq4,perlfaq5,perlfaq6,perlfaq8, andperlfaq9 have seen various updates and modernizations.
The following additions or changes have been made to diagnostic output, including warnings and fatal error messages. For the complete list of diagnostic messages, seeperldiag.
Parsing code internal error (%s)
New fatal error produced when parsing code supplied by an extension violated the parser's API in a detectable way.
Use of qw(...) as parentheses is deprecated
See"Use of qw(...) as parentheses" for details.
warn anddie now produce 'Wide character' warnings when fed a character outside the byte range if STDERR is a byte-sized handle.
The use of a deprecatedgoto construct has been removed[perl #74404].
The newt/lib/universal.t script tests the Internal::* functions and other things inuniversal.c.
A rare race condition int/op/while_readdir.t has been fixed, stopping it from failing randomly when running tests in parallel.
The newt/op/leaky-magic.t script tests that magic applied to variables in the main packages does not affect other packages.
MakePerlIOUnix_open honour default permissions on VMS.
Whenperlio became the default andunixio became the default bottom layer, the most common path for creating files from Perl becamePerlIOUnix_open, which has always explicitly used0666 as the permission mask.
To avoid this,0777 is now passed as the permissions toopen(). In the VMS CRTL,0777 has a special meaning over and above intersecting with the current umask; specifically, it allows Unix syscalls to preserve native default permissions.
CALL_FPTR andCPERLscope have been deprecated.
Those are left from an old implementation ofMULTIPLICITY using C++ objects, which was removed in Perl 5.8. Nowadays these macros do exactly nothing, so they shouldn't be used anymore.
For compatibility, they are still defined for externalXS code. Only extensions definingPERL_CORE must be updated now.
lex_stuff_pvs() has been added as a convenience macro wrappinglex_stuff_pvn() for literal strings.
The recursive part of the peephole optimizer is now hookable.
In addition toPL_peepp, for hooking into the toplevel peephole optimizer, aPL_rpeepp is now available to hook into the optimizer recursing into side-chains of the optree.
A regression introduced in Perl 5.12.0, makingmy $x = 3; $x = length(undef) result in$x set to3 has been fixed.$x will now beundef.
A fatal error in regular expressions when processing UTF-8 data has been fixed[perl #75680].
An erroneous regular expression engine optimization that caused regex verbs like*COMMIT to sometimes be ignored has been removed.
The Perl debugger now also works in taint mode[perl #76872].
Several memory leaks in cloning and freeing threaded Perl interpreters have been fixed[perl #77352].
A possible string corruption when doing regular expression matches on overloaded objects has been fixed[perl #77084].
Magic applied to variables in the main package no longer affects other packages. See"Magic variables outside the main package" above[perl #76138].
Opening a glob reference viaopen $fh, ">", \*glob will no longer cause the glob to be corrupted when the filehandle is printed to. This would cause perl to crash whenever the glob's contents were accessed[perl #77492].
The postincrement and postdecrement operators,++ and--, used to cause leaks when being used on references. This has now been fixed.
A bug when replacing the glob of a loop variable within the loop has been fixed[perl #21469]. This means the following code will no longer crash:
for $x (...) { *x = *y;}Perl would segfault if the undocumentedInternals functions that used reference prototypes were called with the&foo() syntax, e.g.&Internals::SvREADONLY(undef)[perl #77776].
These functions now callSvROK on their arguments before dereferencing them withSvRV, and we test for this case int/lib/universal.t.
When assigning a list with duplicated keys to a hash, the assignment used to return garbage and/or freed values:
@a = %h = (list with some duplicate keys);This has now been fixed[perl #31865].
An earlier release of the 5.13 series of Perl changed the semantics of opening a reference to a copy of a glob:
my $var = *STDOUT;open my $fh, '>', \$var;This was a mistake, and the previous behaviour from Perl 5.10 and 5.12, which is to treat \$var as a scalar reference, has now been restored.
The regular expression bracketed character class[\8\9] was effectively the same as[89\000], incorrectly matching a NULL character. It also gave incorrect warnings that the8 and9 were ignored. Now[\8\9] is the same as[89] and gives legitimate warnings that\8 and\9 are unrecognized escape sequences, passed-through.
warn() anddie() now respect utf8-encoded scalars[perl #45549].
The upgrade to Encode-2.40 has caused some tests in the libwww-perl distribution on CPAN to fail. (Specifically,base/message-charset.t tests 33-36 in version 5.836 of that distribution now fail.)
The upgrade to ExtUtils-MakeMaker-6.57_05 has caused some tests in the Module-Install distribution on CPAN to fail. (Specifically,02_mymeta.t tests 5 and 21,18_all_from.t tests 6 and 15,19_authors.t tests 5, 13, 21 and 29, and20_authors_with_special_characters.t tests 6, 15 and 23 in version 1.00 of that distribution now fail.)
Perl 5.13.5 represents approximately one month of development since Perl 5.13.4 and contains 74558 lines of changes across 549 files from 45 authors and committers:
Abigail, Alexander Alekseev, Aristotle Pagaltzis, Ben Morrow, Bram, brian d foy, Chas. Owens, Chris 'BinGOs' Williams, Craig A. Berry, Curtis Jewell, Dagfinn Ilmari Mannsåker, David Golden, David Leadbeater, David Mitchell, Eric Brine, Father Chrysostomos, Florian Ragwitz, Gisle Aas, Jan Dubois, Jerry D. Hedden, Jesse Vincent, Jim Cromie, Jirka Hruška, Karl Williamson, Michael G. Schwern, Nicholas Clark, Paul Johnson, Philippe Bruhat (BooK), Piotr Fusik, Rafael Garcia-Suarez, Rainer Tammer, Reini Urban, Ricardo Signes, Rob Hoelz, Robin Barker, Steffen Mueller, Steve Hay, Steve Peters, Todd Rinaldo, Tony Cook, Vincent Pit, Yves Orton, Zefram, Zsbán Ambrus, Ævar Arnfjörð Bjarmason.
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.
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 theperlbug 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 ofperl -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.
TheChanges file for an explanation of how to view exhaustive details on what changed.
TheINSTALL file for how to build Perl.
TheREADME file for general stuff.
TheArtistic andCopying files for copyright information.
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