[ 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 v5.19.1
+perldelta - what is new for perl v5.19.2
=head1 DESCRIPTION
-This document describes differences between the 5.19.0 release and the 5.19.1
+This document describes differences between the 5.19.1 release and the 5.19.2
release.
+If you are upgrading from an earlier release such as 5.19.0, first read
+L<perl5191delta>, which describes differences between 5.19.0 and 5.19.1.
+
=head1 Notice
XXX Any important notices here
enhancements. Particularly prominent performance optimisations could go
here, but most should go in the L</Performance Enhancements> section.
-[ List each enhancement as a =head2 entry ]
+=head2 More consistent prototype parsing
+
+Multiple semicolons in subroutine prototypes have long been tolerated and
+treated as a single semicolon. There was one case where this did not
+happen. A subroutine whose prototype begins with "*" or ";*" can affect
+whether a bareword is considered a method name or sub call. This now
+applies also to ";;;*".
+
+Whitespace has long been allowed inside subroutine prototypes, so
+C<sub( $ $ )> is equivalent to C<sub($$)>, but until now it was stripped
+when the subroutine was parsed. Hence, whitespace was I<not> allowed in
+prototypes set by C<Scalar::Util::set_prototype>. Now it is permitted,
+and the parser no longer strips whitespace. This means
+C<prototype &mysub> returns the original prototype, whitespace and all.
=head1 Security
XXX Remove this section if inapplicable.
-The following modules will be removed from the core distribution in a future
-release, and will at that time need to be installed from CPAN. Distributions
-on CPAN which require these modules will need to list them as prerequisites.
+The following modules will be removed from the core distribution in a
+future release, and will at that time need to be installed from CPAN.
+Distributions on CPAN which require these modules will need to list them as
+prerequisites.
The core versions of these modules will now issue C<"deprecated">-category
-warnings to alert you to this fact. To silence these deprecation warnings,
+warnings to alert you to this fact. To silence these deprecation warnings,
install the modules in question from CPAN.
Note that these are (with rare exceptions) fine modules that you are encouraged
-to continue to use. Their disinclusion from core primarily hinges on their
+to continue to use. Their disinclusion from core primarily hinges on their
necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
not usually on concerns over their design.
-XXX Note that deprecated modules should be listed here even if they are listed
-as an updated module in the L</Modules and Pragmata> section.
-
=over
-=item *
-
-...
+XXX Note that deprecated modules should be listed here even if they are listed
+as an updated module in the L</Modules and Pragmata> section.
=back
=item *
-Test::Harness has been upgraded from version 3.26 to 3.28
+L<ExtUtils::Embed> has been upgraded from version 1.30 to 1.31
+
+The generated C<C> code now incorporates bug fixes present in
+F<miniperlmain.c>, and has whitespace changes. It now uses
+C<#include "..."> for header files instead of C<< #include <...> >>.
+This should not make any difference, unless programs embedding C<libperl>
+happen to have local and incompatible files named F<EXTERN.h>, F<XSUB.h> or
+F<perl.h>, as these will now be picked up instead of the installed Perl
+headers.
+
+The C<canon()> function now correctly handles packages with multiple C<::>
+separators when the I<$as> parameter is not I</>. Given that it used to
+generate strings which would likely be syntax errors or pathnames instead of
+filenames, we infer that from the complete lack of bug reports no-one was
+using this functionality. (C<ExtUtils::Miniperl> is now using it.)
+
+=item *
+
+L<ExtUtils::Miniperl> has been upgraded and given a version of 1.
+Previously it did not have a version number.
-Memory usage is dramatically reduced. t/harness now uses about 10% of the
-memory used by 3.26 and earlier.
+C<writemain()> now takes an optional first argument. A reference to a scalar
+is treated as a filename to be opened and written to. Any other reference is
+used as the filehandle to write to. Otherwise the existing default remains,
+to write to C<STDOUT>.
-C<PERL5LIB> is always propagated to a test's C<@INC>, even under C<-T>.
+C<writemain()> has been refactored to use functions from L<ExtUtils::Embed>,
+reducing code size and duplication. The internal function C<canon()> has been
+deleted.
=item *
-Unicode::UCD has been upgraded from version 0.51 to 0.52.
+L<POSIX> has been upgraded from version 1.33 to 1.34.
-A function, L<Unicode::UCD/search_invlist()> is now available to do
-search an inversion list or map for a code point.
+C<POSIX::AUTOLOAD> will no longer infinitely recurse if the shared
+object fails to load.
+
+=item *
+
+L<Storable> has been upgraded from version 2.43 to 2.44.
+
+Calling C<STORABLE_attach> hooks no longer leaks memory. [perl #118829]
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<XXX>
+=head3 L<perlexperiment>
=over 4
=item *
-XXX Description of the change here
+Code in regular expressions, regular expression backtracking verbs,
+and lvalue subroutines are no longer listed as experimental. (This
+also affects L<perlre> and L<perlsub>.)
+
+=back
+
+=head3 L<perlfunc>
+
+=over 4
+
+=item *
+
+Since Perl v5.10, it has been possible for subroutines in @INC to return
+a reference to a scalar holding initial source code to prepend to the file.
+This is now documented.
=back
=item *
-XXX L<message|perldiag/"message">
+L<Missing ']' in prototype for %s : %s|perldiag/"Missing ']' in prototype
+for %s : %s">
+
+(W illegalproto) A grouping was started with C<[> but never closed with
+C<]>.
=back
=item *
-XXX Describe change here
+Under rare circumstances, one could get a "Can't coerce readonly REF to
+string" instead of the customary "Modification of a read-only value". This
+alternate error message has been removed.
+
+=item *
+
+"Ambiguous use of * resolved as operator *": This and similar warnings
+about "%" and "&" used to occur in some circumstances where there was no
+operator of the type cited, so the warning was completely wrong. This has
+been fixed [perl #117535, #76910].
+
+=item *
+
+Warnings about malformed subroutine prototypes are now more consistent in
+how the prototypes are rendered. Some of these warnings would truncate
+prototypes containing nulls. In other cases one warning would suppress
+another. The warning about illegal characters in prototypes no longer says
+"after '_'" if the bad character came before the underscore.
+
+=item *
+
+L<Perl folding rules are not up-to-date for 0x%X; please use the perlbug
+utility to report; in regex; marked by <-- HERE in
+mE<sol>%sE<sol>|perldiag/"Perl folding rules are not up-to-date for 0x%X;
+please use the perlbug utility to report; in regex; marked by <-- HERE in
+m/%s/">
+
+This message is now only in the regexp category, and not in the deprecated
+category. It is still a default (i.e., severe) warning [perl #89648].
+
+=item *
+
+The debugger's "n" command now respects lvalue subroutines and steps over
+them [perl #118839].
=back
=item *
-XXX
+F<installperl> and F<installman>'s option handling has been refactored to use
+L<Getopt::Long>. Both are used by the F<Makefile> C<install> targets, and
+are not installed, so these changes are only likely to affect custom
+installation scripts.
+
+=over 4
+
+=item *
+
+single letter options now also have long names
+
+=item *
+
+invalid options are now rejected
+
+=item *
+
+command line arguments that are not options are now rejected
+
+=item *
+
+Each now has a C<--help> option to display the usage message.
+
+=back
+
+The behaviour for all valid documented invocations is unchanged.
=back
=over 4
-=item Mixed-endian platforms
+=item MidnightBSD
-The code supporting C<pack> and C<unpack> operations on mixed endian
-platforms has been removed. We believe that Perl has long been unable to
-build on mixed endian architectures (such as PDP-11s), so we don't think
-that this change will affect any platforms which are able to build v5.18.0.
+C<objformat> was removed from version 0.4-RELEASE of MidnightBSD and had been
+deprecated on earlier versions. This caused the build environment to be
+erroneously configured for C<a.out> rather than C<elf>. This has been now
+been corrected.
=back
=item *
-The functions C<my_swap>, C<my_htonl> and C<my_ntohl> have been removed.
-It is unclear why these functions were ever marked as I<A>, part of the
-API. XS code can't call them directly, as it can't rely on them being
-compiled. Unsurprisingly, no code on CPAN references them.
+The Makefile shortcut targets for many rarely (or never) used testing and
+profiling targets have been removed, or merged into the only other Makefile
+target that uses them. Specifically, these targets are gone, along with
+documentation that referenced them or explained how to use them:
+
+ check.third check.utf16 check.utf8 coretest minitest.prep
+ minitest.utf16 perl.config.dashg perl.config.dashpg
+ perl.config.gcov perl.gcov perl.gprof perl.gprof.config
+ perl.pixie perl.pixie.atom perl.pixie.config perl.pixie.irix
+ perl.third perl.third.config perl.valgrind.config purecovperl
+ pureperl quantperl test.deparse test.taintwarn test.third
+ test.torture test.utf16 test.utf8 test_notty.deparse
+ test_notty.third test_notty.valgrind test_prep.third
+ test_prep.valgrind torturetest ucheck ucheck.third ucheck.utf16
+ ucheck.valgrind utest utest.third utest.utf16 utest.valgrind
+
+It's still possible to run the relevant commands by "hand" - no underlying
+functionality has been removed.
+
+=item *
+
+It is now possible to keep Perl from initializing locale handling.
+For the most part, Perl doesn't pay attention to locale. (See
+L<perllocale>.) Nonetheless, until now, on startup, it has always
+initialized locale handling to the system default, just in case the
+program being executed ends up using locales. (This is one of the first
+things a locale-aware program should do, long before Perl knows if it
+will actually be needed or not.) This works well except when Perl is
+embedded in another application which wants a locale that isn't the
+system default. Now, if the environment variable
+C<PERL_SKIP_LOCALE_INIT> is set at the time Perl is started, this
+initialization step is skipped. Prior to this, on Windows platforms,
+the only workaround for this deficiency was to use a hacked-up copy of
+internal Perl code. Applications that need to use older Perls can
+discover if the embedded Perl they are using needs the workaround by
+testing that the C preprocessor symbol C<HAS_SKIP_LOCALE_INIT> is not
+defined. (RT #38193)
+
+=item *
+
+C<BmRARE> and C<BmPREVIOUS> have been removed. They were not used anywhere
+and are not part of the API. For XS modules, they are now #defined as 0.
+
+=item *
+
+C<sv_force_normal>, which usually croaks on read-only values, used to allow
+read-only values to be modified at compile time. This has been changed to
+croak on read-only values regardless. This change uncovered several core
+bugs.
=back
=item *
-The OP allocation code now returns correctly aligned memory in all cases
-for C<struct pmop>. Previously it could return memory only aligned to a
-4-byte boundary, which is not correct for an ithreads build with 64 bit IVs
-on some 32 bit platforms. Notably, this caused the build to fail completely
-on sparc GNU/Linux. [RT #118055]
+There have been several fixes related to Perl's handling of locales. perl
+#38193 was described above in L</Internal Changes>.
+Also fixed is #112208 in which the error string in C<$!> displayed as
+garbage in many UTF-8 locales;
+#118197, where the radix (decimal point) character had to be an ASCII
+character (which doesn't work for some non-Western languages);
+and #115808, in which C<POSIX::setlocale()> on failure returned an
+C<undef> which didn't warn about not being defined even if those
+warnings were enabled.
+
+=item *
+
+The dtrace sub-entry probe now works with lexical subs, instead of
+crashing [perl #118305].
+
+=item *
+
+Compiling a C<split> operator whose third argument is a named constant
+evaulating to 0 no longer causes the constant's value to change.
+
+=item *
+
+A named constant used as the second argument to C<index> no longer gets
+coerced to a string if it is a reference, regular expression, dualvar, etc.
=item *
-The debugger's C<man> command been fixed. It was broken in the v5.18.0
-release. The C<man> command is aliased to the names C<doc> and C<perldoc> -
-all now work again.
+A named constant evaluating to the undefined value used as the second
+argument to C<index> no longer produces "uninitialized" warnings at compile
+time. It will still produce them at run time.
+
+=item *
+
+When a scalar was returned from a subroutine in @INC, the referenced scalar
+was magically converted into an IO thingy, possibly resulting in "Bizarre
+copy" errors if that scalar continued to be used elsewhere. Now Perl uses
+an internal copy of the scalar instead.
+
+=item *
+
+Undefining an inlinable lexical subroutine (C<my sub foo() { 42 } undef
+&foo>) would result in a crash if warnings were turned on.
+
+=item *
+
+Certain uses of the C<sort> operator are optimised to modify an array in
+place, such as C<@a = sort @a>. During the sorting, the array is made
+read-only. If a sort block should happen to die, then the array remained
+read-only even outside the C<sort>. This has been fixed.
+
+=item *
+
+C<$a> and C<$b> inside a sort block are aliased to the actual arguments to
+C<sort>, so they can be modified through those two variables. This did not
+always work, e.g., for lvalue subs and C<$#ary>, and probably many other
+operators. It works now.
+
+=item *
+
+The arguments to C<sort> are now all in list context. If the C<sort>
+itself were called in void or scalar context, then I<some>, but not all, of
+the arguments used to be in void or scalar context.
+
+=item *
+
+Subroutine prototypes with Unicode characters above U+00FF were getting
+mangled during closure cloning. This would happen with subroutines closing
+over lexical variables declared outside, and with lexical subs.
+
+=item *
+
+In regular expressions containing multiple code blocks, the values of
+C<$1>, C<$2>, etc., set by nested regular expression calls would leak from
+one block to the next. Now these variables always refer to the outer
+regular expression at the start of an embedded block [perl #117917].
+
+=item *
+
+C<UNIVERSAL::can> now treats its first argument the same way that method
+calls do: Typeglobs and glob references with non-empty IO slots are treated
+as handles, and strings are treated as filehandles, rather than packages,
+if a handle with that name exists [perl #113932].
+
+=item *
+
+Method calls on typeglobs (e.g., C<< *ARGV->getline >>) used to stringify
+the typeglob and then look it up again. Combined with changes in Perl
+5.18.0, this allowed C<< *foo->bar >> to call methods on the "foo" package
+(like C<< foo->bar >>). In some cases it could cause the method to be
+called on the wrong handle. Now a typeglob argument is treated as a
+handle (just like C<< (\*foo)->bar >>), or, if its IO slot is empty, an
+error is raised.
+
+=item *
+
+Under copy-on-write builds (the default as of 5.19.1) C<${'_<-e'}[0]> no
+longer gets mangled. This is the first line of input saved for the
+debugger's use for one-liners [perl #118627].
+
+=item *
+
+Assigning a vstring to a tied variable or to a subroutine argument aliased
+to a nonexistent hash or array element now works, without flattening the
+vstring into a regular string.
+
+=item *
+
+C<pos>, C<tie>, C<tied> and C<untie> did not work
+properly on subroutine arguments aliased to nonexistent
+hash and array elements [perl #77814, #27010].
+
+=item *
+
+The C<< => >> fat arrow operator can now quote built-in keywords even if it
+occurs on the next line, making it consistent with how it treats other
+barewords.
=back
=item *
-XXX
+One of the bug fixes has accidentally thrown line numbers off in rare
+cases, causing test failures for some CPAN modules. This will hopefully be
+fixed soon [perl #118931].
=back
https://perl5.git.perl.org / perl5.git / blobdiff