=encoding utf8
-=for release_engineer
-* changelogged up to f4beb78
-* the mauve module will not be part of the release, so it's not changelogged
-yet. it also added some new api functions. those aren't covered either, as they
-might go away again in case mauve gets rolled back for 5.13.5.
-
=head1 NAME
[ this is a template for a new perldelta file. Any text flagged as
XXX needs to be processed before release. ]
-perldelta - what is new for perl v5.13.5
+perldelta - what is new for perl v5.13.6
=head1 DESCRIPTION
-This document describes differences between the 5.13.4 release and
-the 5.13.5 release.
+This document describes differences between the 5.13.5 release and
+the 5.13.6 release.
-If you are upgrading from an earlier release such as 5.13.3, first read
-L<perl5134delta>, which describes differences between 5.13.3 and
-5.13.4.
+If you are upgrading from an earlier release such as 5.13.4, first read
+L<perl5135delta>, which describes differences between 5.13.4 and
+5.13.5.
=head1 Notice
enhancements. Particularly prominent performance optimisations could go
here, but most should go in the L</Performance Enhancements> section.
-=head2 Adjacent pairs of nextstate opcodes are now optimized away
+[ List each enhancement as a =head2 entry ]
+
+=head2 C<(?^...)> regex construct added to signify default modifiers
+
+A caret (also called a "cirumflex accent") C<"^"> immediately following
+a C<"(?"> in a regular expression now means that the subexpression is to
+not inherit the surrounding modifiers such as C</i>, but to revert to the
+Perl defaults. Any modifiers following the caret override the defaults.
+
+The stringification of regular expressions now uses this notation. The
+main purpose of this is to allow tests that rely on the stringification
+to not have to change when new modifiers are added. See
+L<perlre/Extended Patterns>.
+
+=head2 C<"d">, C<"l">, and C<"u"> regex modifiers added
+
+These modifiers are currently only available within a C<(?...)> construct.
+
+The C<"l"> modifier says to compile the regular expression as if it were
+in the scope of C<use locale>, even if it is not.
+
+The C<"u"> modifier currently does nothing.
-Previously, in code such as
+The C<"d"> modifier is used in the scope of C<use locale> to compile the
+regular expression as if it were not in that scope.
+See L<perlre/(?dlupimsx-imsx)>.
- use constant DEBUG => 0;
+=head2 C<\N{...}> now handles Unicode named character sequences
- sub GAK {
- warn if DEBUG;
- print "stuff\n";
- }
+Unicode has a number of named character sequences, in which particular sequences
+of code points are given names. C<\N{...}> now recognizes these.
+See L<charnames>.
-the ops for C<warn if DEBUG;> would be folded to a C<null> op (C<ex-const>), but
-the C<nextstate> op would remain, resulting in a runtime op dispatch of
-C<nextstate>, C<nextstate>, ...
+=head2 New function C<charnames::string_vianame()>
-The execution of a sequence of C<nexstate> ops is indistinguishable from just
-the last C<nextstate> op, so teach the peephole optimiser to eliminate the first
-of a pair of C<nextstate> ops. (Except where the first carries a label, as
-labels mustn't be eliminated by the optimiser, and label usage isn't
-conclusively known at compile time.)
+This function is a run-time version of C<\N{...}>, returning the string
+of characters whose Unicode name is its parameter. It can handle
+Unicode named character sequences, whereas the pre-existing
+C<charnames::vianame()> cannot, as the latter returns a single code
+point.
+See L<charnames>.
=head1 Security
=head1 Incompatible Changes
-=head2 Magic Variables Outside the Main Package
+=head2 Stringification of regexes has changed
-In previous versions of perl, magic variables like C<$!>, C<%SIG>, etc. would
-'leak' into other packages. So C<%foo::SIG> could be used to access signals,
-C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
+Default regular expression modifiers are now notated by using
+C<(?^...)>. Code relying on the old stringification will fail. The
+purpose of this is so that when new modifiers are added, such code will
+not have to change (after this one time), as the stringification will
+automatically incorporate the new modifiers.
-This was a bug, or an 'unintentional' feature, which caused various ill
-effects, such as signal handlers being wiped when modules were loaded, etc.
+Code that needs to work properly with both old- and new-style regexes
+can avoid the whole issue by using (for Perls since 5.9.5):
-This has been fixed (or the feature has been removed, depending on how you
-see it).
+ use re qw(regexp_pattern);
+ my ($pat, $mods) = regexp_pattern($re_ref);
-=head2 C API changes
+where C<$re_ref> is a reference to a compiled regular expression. Upon
+return, C<$mods> will be a string containing all the non-default
+modifiers used when the regular expression was compiled, and C<$pattern>
+the actual pattern.
-The first argument of the C API function C<Perl_fetch_cop_label> has changed
-from C<struct refcounted he *> to C<COP *>, to better insulate the user from
-implementation details.
+If the actual stringification is important, or older Perls need to be
+supported, you can use something like the following:
-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.)
+ # Accept both old and new-style stringification
+ my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? '^' : '-xism';
+
+And then use C<$modifiers> instead of C<-xism>.
+
+=head2 Regular expressions retain their localeness when interpolated
+
+Regular expressions compiled under C<"use locale"> now retain this when
+interpolated into a new regular expression compiled outside a
+C<"use locale">, and vice-versa.
+
+Previously, a regular expression interpolated into another one inherited
+the localeness of the surrounding one, losing whatever state it
+originally had. This is considered a bug fix, but may trip up code that
+has come to rely on the incorrect behavior.
+
+[ List each incompatible change as a =head2 entry ]
=head1 Deprecations
=item *
-Scalars containing regular expressions now only allocate the part of the C<SV>
-body they actually use, saving some space.
+XXX
=back
=item *
-C<blib> has been upgraded from version 1.05 to 1.06.
+C<File::DosGlob> has been upgraded from version 1.02 to 1.03.
-=item *
-
-C<bignum>, C<bigint>, and C<bigrat> have been upgraded from version 0.23 to
-0.24.
+It allows patterns containing literal parentheses (they no longer need to
+be escaped). On Windows, it no longer adds an extra F<./> to the file names
+returned when the pattern is a relative glob with a drive specification,
+like F<c:*.pl>
+L<[perl #71712]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71712>.
=item *
-C<Data::Dumper> has been upgraded from version 2.126 to XXX.
+C<File::Find> has been upgraded from version 1.17 to 1.18.
-This fixes a crash when using custom sort functions that might cause the stack
-to change.
+It improves handling of backslashes on Windows, so that paths such as
+F<c:\dir\/file> are no longer generated
+L<[perl #71710]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71710>.
=item *
-C<Errno> has been upgraded 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
-by C<Errno>. This has been fixed (RT#77416).
-
-=item *
-
-C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_01.
-
-=item *
+C<Locale::Maketext> has been upgraded from version 1.15 to 1.16.
-C<Filter::Simple> has been upgraded from version 0.84 to 0.85.
+It fixes an infinite loop in C<Locale::Maketext::Guts::_compile()> when
+working with tainted values
+(L<CPAN RT #40727|https://rt.cpan.org/Public/Bug/Display.html?id=40727>).
=item *
-C<Math::BigInt> has been upgraded from version 1.89_01 to 1.90.
-C<Math::BigInt::Calc> has been upgraded from version 0.52 to 0.53.
-
-This fixes incorrect results when computing binomial coefficients (RT#77640).
+C<NEXT> has been upgraded from version 0.64 to 0.65.
=item *
-C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.21.
+C<PathTools> has been upgraded from version 3.31_01 to 3.33.
=item *
-C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
+C<sigtrap> has been upgraded from version 1.04 to 1.05.
-Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
+It no longer tries to modify read-only arguments when generating a
+backtrace
+L<[perl #72340]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72340>.
=item *
-C<Unicode::Collate> has been upgraded from version 0.56 to 0.59.
+C<Unicode::Collate> has been upgraded from version 0.59 to 0.60
=item *
-C<XSLoader> has been upgraded from version 0.10 to 0.11.
+C<Unicode::Normalize> has been upgraded from version 1.06 to 1.07
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<perlapi>
+=head3 L<XXX>
=over 4
=item *
-Many of the optree construction functions are now documented.
+The documentation for the C<SvTRUE> macro was simply wrong in stating that
+get-magic is not processed. It has been corrected.
=back
entries for each change
Use L<XXX> with program names to get proper documentation linking. ]
-=head3 L<h2ph>
+=head3 L<XXX>
=over 4
=item *
-The use of a deprecated C<goto> construct has been removed (RT#74404).
+XXX
=back
=item *
-A rare race condition in F<t/op/while_readdir.t> has been fixed, stopping it
-from failing randomly when running tests in parallel.
-
-=item *
-
-The new F<t/op/leaky-magic.t> script tests that magic applied to variables in
-the main packages does not affect other packages.
+XXX
=back
=over 4
-=item VMS
-
-=over 4
-
-=item *
-
-Make PerlIOUnix_open honor default permissions on VMS.
-
-When perlio became the default and unixio became the default bottom layer, the
-most common path for creating files from Perl became C<PerlIOUnix_open>, which
-has always explicitly used C<0666> as the permission mask.
-
-To avoid this, C<0777> is now passed as the permissions to C<open()>. In the VMS
-CRTL, C<0777> has a special meaning over and above intersecting with the current
-umask; specifically, it allows Unix syscalls to preserve native default
-permissions.
+=item XXX-some-platform
-=back
+XXX
=back
=item *
-C<CALL_FPTR> and C<CPERLscope> have been removed deprecated.
+See L</Regular expressions retain their localeness when interpolated>,
+above.
-Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
-which has been removed in 5.8. Nowadays these macros do exactly nothing, so they
-shouldn't be used anymore.
+=item *
-For compatibility, they are still defined for external C<XS> code. Only
-extensions defining C<PERL_CORE> must be updated now.
+The C<sv_cmp_flags>, C<sv_cmp_locale_flags>, C<sv_eq_flags> and
+C<sv_collxfrm_flags> functions have been added. These are like their
+non-_flags counterparts, but allow one to specify whether get-magic is
+processed.
+
+The C<sv_cmp>, C<sv_cmp_locale>, C<sv_eq> and C<sv_collxfrm> functions have
+been replaced with wrappers around the new functions.
=item *
-C<lex_stuff_pvs()> has been added as a convenience macro wrapping
-C<lex_stuff_pvn()> for literal strings.
+A new C<sv_2bool_flags> function has been added.
+
+This is like C<sv_2bool>, but it lets the calling code decide whether
+get-magic is handled. C<sv_2bool> is now a macro that calls the new
+function.
=item *
-The recursive part of the peephole optimizer is how hookable.
+A new macro, C<SvTRUE_nomg>, has been added.
-In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
-C<PL_rpeepp> is now available to hook into the optimizer recursing into
-side-chains of the optree.
+This is like C<SvTRUE>, except that it does not process magic. It uses the
+new C<sv_2bool_flags> function.
+
+=item *
+
+C<sv_catsv_flags> no longer calls C<mg_get> on its second argument (the
+source string) if the flags passed to it do not include SV_GMAGIC. So it
+now matches what the documentation says it does.
=back
=item *
-A regression introduced in perl 5.12.0, making
-C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
-fixed. C<$x> will now be C<undef>.
+A regular expression match in the right-hand side of a global substitution
+(C<s///g>) that is in the same scope will no longer cause match variables
+to have the wrong values on subsequent iterations. This can happen when an
+array or hash subscript is interpolated in the right-hand side, as in
+C<s|(.)|@a{ print($1), /./ }|g>
+L<[perl #19078]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=19078>.
=item *
-A fatal error in regular expressions when processing UTF-8 data has been fixed
-(RT#75680).
+Constant-folding used to cause
-=item *
+ $text =~ ( 1 ? /phoo/ : /bear/)
-An erroneous regular expression engine optimization, that caused regex verbs
-like C<*COMMIT> to sometimes be ignored, has been removed.
+to turn into
-=item *
+ $text =~ /phoo/
-The perl debugger now also works in taint mode (RT#76872).
+at compile time. Now it correctly matches against C<$_>
+L<[perl #20444]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=20444>.
=item *
-Several memory leaks in cloning and freeing threaded perl interpreters have been
-fixed (RT#77352).
+Parsing Perl code (either with string C<eval> or by loading modules) from
+within a C<UNITCHECK> block no longer causes the interpreter to crash
+L<[perl #70614]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=70614>.
=item *
-A possible string corruption when doing regular expression matches on overloaded
-objects has been fixed (RT#77084).
+When C<-d> is used on the shebang (C<#!>) line, the debugger now has access
+to the lines of the main program. In the past, this sometimes worked and
+sometimes did not, depending on what order things happened to be arranged
+in memory
+L<[perl #71806]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71806>.
=item *
-Magic applied to variables in the main package no longer affects other
-packages. See L</Magic Variables Outside the Main Package>, above [perl #76138].
+The C<y///> or C<tr///> operator now calls get-magic (e.g., the C<FETCH>
+method of a tie) on its left-hand side just once, not twice
+L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>.
=item *
-Opening a glob reference via C<< open $fh, ">", \*glob >> will no longer cause
-the glob to be corrupted when the file handle is printed to. This would cause
-perl to crash whenever the glob's contents were accessed [perl #77492].
+String comparison (C<eq>, C<ne>, C<lt>, C<gt>, C<le>, C<ge> and
+C<cmp>) and logical not (C<not> and C<!>) operators no longer call magic
+(e.g., tie methods) twice on their operands
+L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>.
+
+This bug was introduced in an earlier 5.13 release, and does not affect
+perl 5.12.
=item *
-The postincremend and postdecrement operators, C<++> and C<--> used to cause
-leaks when being used on references. This has now been fixed.
+When a tied (or other magic) variable is used as, or in, a regular
+expression, it no longer has its C<FETCH> method called twice
+L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>.
+
+This bug was introduced in an earlier 5.13 release, and does not affect
+perl 5.12.
=back
XXX If any significant core contributor has died, we've added a short obituary
here.
+=head1 Errata
+
+=over 4
+
+=item *
+
+Fixed a typo in L<perl5135delta> regarding array slices and smart matching
+
+=back
+
=head1 Acknowledgements
XXX The list of people to thank goes here.
https://perl5.git.perl.org / perl5.git / blobdiff