=head1 NAME
-perldelta - what is new for perl v5.17.1
+[ 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 v5.17.3
=head1 DESCRIPTION
-This document describes differences between the 5.17.0 release and
-the 5.17.1 release.
+This document describes differences between the 5.17.2 release and
+the 5.17.3 release.
-If you are upgrading from an earlier release such as 5.16.0, first read
-L<perl5170delta>, which describes differences between 5.16.0 and
-5.17.0.
+If you are upgrading from an earlier release such as 5.17.1, first read
+L<perl5172delta>, which describes differences between 5.17.1 and
+5.17.2.
-=head1 Core Enhancements
+=head1 Notice
-=head2 More CORE:: subs
+XXX Any important notices here
-Several more built-in functions have been added as subroutines to the
-CORE:: namespace, namely, those non-overridable keywords that can be
-implemented without custom parsers: C<defined>, C<delete>, C<exists>,
-C<glob>, C<pos>, C<protoytpe>, C<scalar>, C<split>, C<study>, and C<undef>.
+=head1 Core Enhancements
-As some of these have prototypes, C<prototype('CORE::...')> has been
-changed to not make a distinction between overridable and non-overridable
-keywords. This is to make C<prototype('CORE::pos')> consistent with
-C<prototype(&CORE::pos)>.
+XXX New core language features go here. Summarise user-visible core language
+enhancements. Particularly prominent performance optimisations could go
+here, but most should go in the L</Performance Enhancements> section.
-=head1 Incompatible Changes
+[ List each enhancement as a =head2 entry ]
-=head2 C</(?{})/> and C</(??{}> have been heavily reworked.
+=head2 Computed Labels
-The implementation of this feature has been almost completely rewritten.
-Although its main intent is to fix bugs, some behaviours, especially
-related to the scope of lexical variables, will have changed. This is
-described more fully in the L</Selected Bug Fixes> section.
+The loop controls C<next>, C<last> and C<redo>, and the special C<dump>
+operator, now allow arbitrary expressions to be used to compute labels at
+run time. Previously, any argument that was not a constant was treated as
+the empty string.
-=head2 C<\N{BELL}> now refers to U+1F514 instead of U+0007
+=head1 Security
-Unicode 6.0 reused the name "BELL" for a different code point than it
-traditionally had meant. Since Perl v5.14, use of this name still
-referred to U+0007, but would raise a deprecated warning. Now, "BELL"
-refers to U+1F514, and the name for U+0007 is "ALERT". All the
-functions in L<charnames> have been correspondingly updated.
+XXX Any security-related notices go here. In particular, any security
+vulnerabilities closed should be noted here rather than in the
+L</Selected Bug Fixes> section.
-=head2 Alphanumeric operators must now be separated from the closing
-delimiter of regular expressions
+[ List each security issue as a =head2 entry ]
-You may no longer write something like:
+=head1 Incompatible Changes
- m/a/and 1
+[ List each incompatible change as a =head2 entry ]
-Instead you must write
+=head2 C<$ENV{foo} = undef> deletes value from environ, like C<delete $ENV{foo}>
- m/a/ and 1
+This facilitates use of C<local()> with C<%ENV> entries. In previous
+versions of Perl, C<undef> was converted to the empty string.
-with whitespace separating the operator from the closing delimiter of
-the regular expression. Not having whitespace has resulted in a
-deprecated warning since Perl v5.14.0.
+=head2 Defined values stored in environment are forced to byte strings
-=head2 C<require> dies for unreadable files
+A value stored in an environment variable has always been stringified. In
+this release, it is converted to be only a byte string. First, it is forced
+to be a only a string. Then if the string is utf8 and the equivalent of
+C<utf8::downgrade> works, that result is used; otherwise, the equivalent of
+C<utf8::encode> is used, and a warning is issued about wide characters
+(L</Diagnostics>).
-When C<require> encounters an unreadable file, it now dies. It used to
-ignore the file and continue searching the directories in @INC
-[perl #113422].
+=head1 Deprecations
-=head2 Upgrade to the Unicode 6.2 beta
+XXX Any deprecated features, syntax, modules etc. should be listed here.
+In particular, deprecated modules should be listed here even if they are
+listed as an updated module in the L</Modules and Pragmata> section.
-Unicode 6.2 is proposing some changes that may very well break some CPAN
-modules. The timing of this nicely coincides with Perl's being early in the
-release cycle. This commit takes the current beta 6.2, adds the proposed
-changes that aren't yet in it, and subtracts the changes that would affect \X
-processing, as those turn out to have errors, and may have to be rethought.
-Unicode has been notified of these problems.
+[ List each deprecation as a =head2 entry ]
-This will allow us to gather data as to whether or not the proposed changes
-cause us problems. These will be presented to Unicode to aid in their final
-decision as to whether or not to go forward with the changes.
+=head1 Performance Enhancements
-These changes will be replaced by the final version of Unicode 6.2 before
-5.18.0 is released.
+XXX Changes which enhance performance without changing behaviour go here. There
+may well be none in a stable release.
-=head1 Performance Enhancements
+[ List each enhancement as a =item entry ]
=over 4
=item *
-The C<x> repetition operator is now folded to a single constant at compile
-time if called in scalar context with constant operands and no parentheses
-around the left operand.
+XXX
=back
=head1 Modules and Pragmata
-=head2 Updated Modules and Pragmata
-
-=over 4
-
-=item *
-
-L<Archive::Extract> has been upgraded from version 0.58 to 0.60.
-
-Work around an edge case on Linux with Busybox's unzip.
-
-=item *
-
-L<Archive::Tar> has been upgraded from version 1.82 to 1.88.
-
-ptar now supports -T option and dashless options [rt.cpan.org #75473],
-[rt.cpan.org #75475].
-
-Auto-encode filenames marked as UTF-8 [rt.cpan.org #75474].
-
-Don't use tell on IO::Zlib handles [rt.cpan.org #64339].
-
-Don't try to C<chown> on symlinks.
-
-=item *
-
-L<attributes> has been upgraded from version 0.19 to 0.20.
-
-No visible changes.
-
-=item *
-
-L<autodie> has been upgraded from version 2.10 to 2.11.
-
-No visible changes.
-
-=item *
-
-L<B> has been upgraded from version 1.35 to 1.36.
-
-C<B::COP::stashlen> has been replaced with C<B::COP::stashoff>.
-
-C<B::COP::stashpv> now supports UTF8 package names and embedded NULs.
-
-=item *
-
-L<B::Deparse> has been upgraded from version 1.14 to 1.15.
-
-Avoid warning when run under C<perl -w>.
-
-=item *
-
-L<Class::Struct> has been upgraded from version 0.63 to 0.64.
-
-The constructor now respects overridden accessor methods [perl #29230].
-
-=item *
-
-L<Compress::Raw::Bzip2> has been upgraded from version 2.048 to 2.052.
-
-No visible changes.
-
-=item *
-
-L<Compress::Raw::Zlib> has been upgraded from version 2.048 to 2.054.
-
-Upgrade bundled zlib to version 1.2.7.
-
-Fix build failures on Irix, Solaris, and Win32, and also when building as C++
-[rt.cpan.org #69985], [rt.cpan.org #77030], [rt.cpan.org #75222].
-
-=item *
-
-L<CPAN::Meta> has been upgraded from version 2.120630 to 2.120921.
-
-Split L<CPAN::Meta::Requirements> into its own distribution.
-
-=item *
-
-L<CPAN::Meta::Requirements> has been upgraded from version 2.120630 to 2.122.
-
-Treat undef requirements to C<from_string_hash> as 0 (with a warning).
-
-Added C<requirements_for_module> method.
-
-=item *
-
-L<CPAN::Meta::YAML> has been upgraded from version 0.007 to 0.008.
-
-No visible changes.
-
-=item *
-
-L<CPANPLUS> has been upgraded from version 0.9121 to 0.9130.
+XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
+go here. If Module::CoreList is updated, generate an initial draft of the
+following sections using F<Porting/corelist-perldelta.pl>, which prints stub
+entries to STDOUT. Results can be pasted in place of the '=head2' entries
+below. A paragraph summary for important changes should then be added by hand.
+In an ideal world, dual-life modules would have a F<Changes> file that could be
+cribbed.
-Allow adding F<blib/script> to PATH.
+[ Within each section, list entries as a =item entry ]
-Save the history between invocations of the shell.
+=head2 New Modules and Pragmata
-Handle multiple C<makemakerargs> and C<makeflags> arguments better.
-
-Use C<File::HomeDir> when available, and provide C<PERL5_CPANPLUS_HOME> to
-override the autodetection.
-
-Always re-fetch CHECKSUMS if C<fetchdir> is set.
-
-=item *
-
-L<Digest::MD5> has been upgraded from version 2.51 to 2.52.
-
-Fix Digest::Perl::MD5 OO fallback [rt.cpan.org #66634].
-
-=item *
-
-L<DynaLoader> has been upgraded from version 1.14 to 1.15.
-
-This is due to a minor code change in the XS for the VMS implementation.
-
-=item *
-
-L<ExtUtils::CBuilder> has been upgraded from version 0.280206 to 0.280208.
-
-Manifest files are now correctly embedded for those versions of VC++ which
-make use of them. [perl #111782, #111798].
-
-=item *
-
-L<File::DosGlob> has been upgraded from version 1.07 to 1.08.
-
-There are no visible changes, only minor internal refactorings.
-
-=item *
-
-L<File::Fetch> has been upgraded from version 0.32 to 0.34.
-
-No visible changes.
+=over 4
=item *
-L<File::Spec::Unix> has been upgraded from version 3.39_02 to 3.39_03.
+XXX
-C<abs2rel> could produce incorrect results when given two relative paths or
-the root directory twice [perl #111510].
-
-=item *
+=back
-L<Filter::Util::Call> has been upgraded from version 1.40 to 1.45.
+=head2 Updated Modules and Pragmata
-No visible changes.
+=over 4
=item *
-L<HTTP::Tiny> has been upgraded from version 0.017 to 0.022.
+L<B> has been upgraded from version 1.36 to version 1.37. All C<CVf_*> and
+C<GVf_*> and more SV-related flag values are now provided as constants in
+the C<B::> namespace and available for export. The default export list has
+not changed.
-Add SSL verification features [github #6], [github #9].
+=back
-Include the final URL in the response hashref.
+=head2 Removed Modules and Pragmata
-Add C<local_address> option.
+=over 4
=item *
-L<IO> has been upgraded from version 1.25_06 to 1.25_07.
-
-C<sync()> can now be called on read-only file handles [perl #64772].
+XXX
-=item *
+=back
-L<IPC::Cmd> has been upgraded from version 0.76 to 0.78.
+=head1 Documentation
-Use C<POSIX::_exit> instead of C<exit> in C<run_forked> [rt.cpan.org #76901].
+XXX Changes to files in F<pod/> go here. Consider grouping entries by
+file and be sure to link to the appropriate page, e.g. L<perlfunc>.
-=item *
+=head2 New Documentation
-L<Memoize> has been upgraded from version 1.02 to 1.03.
+XXX Changes which create B<new> files in F<pod/> go here.
-Fix the C<MERGE> cache option.
+=head3 L<XXX>
-=item *
+XXX Description of the purpose of the new file here
-L<Module::Build> has been upgraded from version 0.39_01 to 0.40.
+=head2 Changes to Existing Documentation
-Fixed bug where modules without C<$VERSION> might have a version of '0' listed
-in 'provides' metadata, which will be rejected by PAUSE.
+XXX Changes which significantly change existing files in F<pod/> go here.
+However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
+section.
-Fixed bug in PodParser to allow numerals in module names.
+=head3 L<perlfunc>, L<perlop>
-Fixed bug where giving arguments twice led to them becoming arrays, resulting
-in install paths like F<ARRAY(0xdeadbeef)/lib/Foo.pm>.
+=over 4
=item *
-L<Module::Load::Conditional> has been upgraded from version 0.46 to 0.50.
+Loop control verbs (C<dump>, C<goto>, C<next>, C<last> and C<redo>) have
+always had the same precedence as assignment operators, but this was never
+documented until now.
-Fix use of C<requires> on perls installed to a path with spaces.
+=back
-=item *
+=head1 Diagnostics
-L<Object::Accessor> has been upgraded from version 0.42 to 0.44.
+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 L<perldiag>.
-No visible changes.
+XXX New or changed warnings emitted by the core's C<C> code go here. Also
+include any changes in L<perldiag> that reconcile it to the C<C> code.
-=item *
+[ Within each section, list entries as a =item entry that links to perldiag,
+ e.g.
-L<Params::Check> has been upgraded from version 0.32 to 0.36.
+ =item *
-No visible changes.
+ L<Invalid version object|perldiag/"Invalid version object">
+]
-=item *
+=head2 New Diagnostics
-L<Parse::CPAN::Meta> has been upgraded from version 1.4402 to 1.4404.
+XXX Newly added diagnostic messages go here
-No visible changes.
+=over 4
=item *
-L<PerlIO::mmap> has been upgraded from version 0.010 to 0.011.
+Attempts to put wide characters into environment variables via %ENV provoke
+the warning "Wide character in setenv".
-No visible changes.
-
-=item *
+=back
-L<PerlIO::via::QuotedPrint> has been upgraded from version 0.06 to 0.07.
+=head3 New Errors
-No visible changes.
+=over 4
=item *
-L<Pod::Html> has been upgraded from version 1.15_02 to 1.16.
-
-The option C<--libpods> has been reinstated. It is deprecated, and its use
-does nothing other than issue a warning that it is no longer supported.
-
-Since the HTML files generated by pod2html claim to have a utf-8 charset,
-actually write the files out using utf-8 [perl #111446].
+XXX L<message|perldiag/"message">
-=item *
+=back
-L<POSIX> has been upgraded from version 1.30 to 1.31.
+=head3 New Warnings
-No visible changes.
+=over 4
=item *
-L<re> has been upgraded from version 0.19 to 0.20.
+XXX L<message|perldiag/"message">
-See note about C<op_comp> in the L</Internal Changes> section below.
+=back
-=item *
+=head2 Changes to Existing Diagnostics
-L<Safe> has been upgraded from version 2.31_01 to 2.33_01.
+XXX Changes (i.e. rewording) of diagnostic messages go here
-XXX where do these dev versions come from?
+=over 4
=item *
-L<Scalar::Util> has been upgraded from version 1.23 to version 1.25.
-
-Fix an overloading issue with C<sum>.
-
-C<first> and C<reduce> now check the callback first (so C<&first(1)> is
-disallowed).
+XXX Describe change here
-Fix C<tainted> on magical values [rt.cpan.org #55763].
-
-Fix C<sum> on previously magical values [rt.cpan.org #61118].
+=back
-Fix reading past the end of a fixed buffer [rt.cpan.org #72700].
+=head1 Utility Changes
-=item *
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
+here. Most of these are built within the directories F<utils> and F<x2p>.
-L<Search::Dict> has been upgraded from version 1.04 to 1.07.
+[ List utility changes as a =head3 entry for each utility and =item
+entries for each change
+Use L<XXX> with program names to get proper documentation linking. ]
-No longer require C<stat> on filehandles.
+=head3 L<XXX>
-Use C<fc> for casefolding.
+=over 4
=item *
-L<Storable> has been upgraded from version 2.35 to 2.36.
+XXX
-No visible changes.
+=back
-=item *
+=head1 Configuration and Compilation
-L<Term::ANSIColor> has been upgraded from version 3.01 to 3.02.
+XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
+go here. Any other changes to the Perl build process should be listed here.
+However, any platform-specific changes should be listed in the
+L</Platform Support> section, instead.
-Add support for italics.
+[ List changes as a =item entry ].
-Improve error handling.
+=over 4
=item *
-L<Test::Harness> has been upgraded from version 3.23 to 3.25.
-
-Fix glob semantics on Win32 [rt.cpan.org #49732].
+XXX
-Don't use Win32::GetShortPathName when calling perl [rt.cpan.org #47890].
+=back
-Ignore -T when reading shebang [rt.cpan.org #64404].
+=head1 Testing
-Handle the case where we don't know the wait status of the test more
-gracefully.
+XXX Any significant changes to the testing of a freshly built perl should be
+listed here. Changes which create B<new> files in F<t/> go here as do any
+large changes to the testing harness (e.g. when parallel testing was added).
+Changes to existing files in F<t/> aren't worth summarising, although the bugs
+that they represent may be covered elsewhere.
-Make the test summary 'ok' line overrideable so that it can be changed to a
-plugin to make the output of prove idempotent.
+[ List each test improvement as a =item entry ]
-Don't run world-writable files.
+=over 4
=item *
-L<Unicode::UCD> has been upgraded from version 0.43 to 0.44.
-
-This adds a function L<all_casefolds()|Unicode::UCD/all_casefolds()>
-that returns all the casefolds.
+XXX
=back
-=head1 Documentation
-
-=head2 Changes to Existing Documentation
-
-=head3 L<perlfaq>
-
-=over 4
+=head1 Platform Support
-=item *
+XXX Any changes to platform support should be listed in the sections below.
-L<perlfaq> has been synchronised with version 5.0150040 from C<CPAN>.
+[ Within the sections, list each platform as a =item entry with specific
+changes as paragraphs below it. ]
-=back
+=head2 New Platforms
-=head3 L<perlcheat>
+XXX List any platforms that this version of perl compiles on, that previous
+versions did not. These will either be enabled by new files in the F<hints/>
+directories, or new subdirectories and F<README> files at the top level of the
+source tree.
=over 4
-=item *
+=item XXX-some-platform
-L<perlcheat> has been reorganized, and a few new sections were added.
+XXX
=back
-=head1 Diagnostics
+=head2 Discontinued Platforms
-=head2 Removals of Diagnostics
+XXX List any platforms that this version of perl no longer compiles on.
=over 4
-=item *
-
-The "Runaway prototype" warning that occurs in bizarre cases has been
-removed as being unhelpful and inconsistent.
-
-=item *
-
-The "Not a format reference" error has been removed, as the only case in
-which it could be triggered was a bug.
+=item XXX-some-platform
-=item *
-
-The "Unable to create sub named %s" error has been removed for the same
-reason.
+XXX
=back
-=head1 Platform Support
-
=head2 Platform-Specific Notes
-XXX note fails on win2k and vms
+XXX List any changes for specific platforms. This could include configuration
+and compilation changes or changes in portability/compatibility. However,
+changes within modules for platforms should generally be listed in the
+L</Modules and Pragmata> section.
=over 4
-=item Win32
-
-C<link> on Win32 now attempts to set C<$!> to more appropriate values
-based on the Win32 API error code. [perl #112272]
+=item XXX-some-platform
-Perl no longer mangles the environment block, e.g. when launching a new
-sub-process, when the environment contains non-ASCII characters. Known
-problems still remain, however, when the environment contains characters
-outside of the current ANSI codepage (e.g. see the item about Unicode in
-C<%ENV> in L<http://perl5.git.perl.org/perl.git/blob/HEAD:/Porting/todo.pod>).
-[perl #113536]
+XXX
=back
=head1 Internal Changes
-=over 4
+XXX Changes which affect the interface available to C<XS> code go here.
+Other significant internal changes for future core maintainers should
+be noted as well.
-=item *
+[ List each change as a =item entry ]
-The C<study> function was made a no-op in 5.16. It was simply disabled via
-a C<return> statement; the code was left in place. Now the code supporting
-what C<study> used to do has been removed.
-
-=item *
-
-Under threaded perls, there is no longer a separate PV allocated for every
-COP to store its package name (C<< cop->stashpv >>). Instead, there is an
-offset (C<< cop->stashoff >>) into the new C<PL_stashpad> array, which
-holds stash pointers.
-
-=item *
-
-In the pluggable regex API, the C<regexp_engine> struct has acquired a new
-field C<op_comp>, which is currently just for perl's internal use, and
-should be initialised to NULL by other regex plugin modules.
+=over 4
=item *
-A new function C<alloccoptash> has been added to the API, but is considered
-experimental. See L<perlapi>.
+XXX
=back
=head1 Selected Bug Fixes
-=over 4
+XXX Important bug fixes in the core language are summarised here.
+Bug fixes in files in F<ext/> and F<lib/> are best summarised in
+L</Modules and Pragmata>.
-=item *
-
-The implementation of code blocks in regular expressions, such as C<(?{})>
-and C<(??{})> has been heavily reworked to eliminate a whole slew of bugs.
-The main user-visible changes are:
+[ List each fix as a =item entry ]
=over 4
=item *
-Code blocks within patterns are now parsed in the same pass as the
-surrounding code; in particular it is no longer necessary to have balanced
-braces: this now works:
-
- /(?{ $x='{' })/
-
-This means that this error message is longer generated:
-
- Sequence (?{...}) not terminated or not {}-balanced in regex
-
-but a new error may be seen:
-
- Sequence (?{...}) not terminated with ')'
-
-In addition, literal code blocks within run-time patterns are only
-compiled once, at perl compile-time:
-
- for my $p (...) {
- # this 'FOO' block of code is compiled once,
- # at the same time as the surrounding 'for' loop
- /$p{(?{FOO;})/;
- }
+C<\w> now matches the code points U+200C (ZERO WIDTH NON-JOINER) and
+U+200D (ZERO WIDTH JOINER). C<\W> no longer matches these. This change
+is because Unicode corrected their definition of what C<\w> should match.
=item *
-Lexical variables are now sane as regards scope, recursion and closure
-behaviour. In particular, C</A(?{B})C/> behaves (from a closure viewpoint)
-exactly like C</A/ && do { B } && /C/>, while C<qr/A(?{B})C/> is like
-C<sub {/A/ && do { B } && /C/}>. So this code now works how you might
-expect, creating three regexes that match 0, 1, and 2:
-
- for my $i (0..2) {
- push @r, qr/^(??{$i})$/;
- }
- "1" =~ $r[1]; # matches
-
-=item *
-
-The C<use re 'eval'> pragma is now only required for code blocks defined
-at runtime; in particular in the following, the text of the C<$r> pattern is
-still interpolated into the new pattern and recompiled, but the individual
-compiled code-blocks within C<$r> are reused rather than being recompiled,
-and C<use re 'eval'> isn't needed any more:
-
- my $r = qr/abc(?{....})def/;
- /xyz$r/;
+C<dump LABEL> no longer leaks its label.
=item *
-Flow control operators no longer crash. Each code block runs in a new
-dynamic scope, so C<next> etc. will not see any enclosing loops and
-C<caller> will not see any calling subroutines. C<return> returns a value
-from the code block, not from any enclosing subroutine.
+Constant folding no longer changes the behaviour of functions like C<stat>
+and C<truncate> that can take either filenames or handles.
+C<stat 1 ? foo : bar> nows treats its argument as a file name (since it is
+an arbitrary expression), rather than the handle "foo".
=item *
-Perl normally caches the compilation of run-time patterns, and doesn't
-recompile if the pattern hasn't changed; but this is now disabled if
-required for the correct behaviour of closures; for example:
-
- my $code = '(??{$x})';
- for my $x (1..3) {
- # recompile to see fresh value of $x each time
- $x =~ /$code/;
- }
-
+C<truncate FOO, $len> no longer falls back to treating "FOO" as a file name
+if the filehandle has been deleted. This was broken in Perl 5.16.0.
=item *
-The C</msix> and C<(?msix)> etc. flags are now propagated into the return
-value from C<(??{})>; this now works:
-
- "AB" =~ /a(??{'b'})/i;
-
-=item *
-
-Warnings and errors will appear to come from the surrounding code (or for
-run-time code blocks, from an eval) rather than from an C<re_eval>:
-
- use re 'eval'; $c = '(?{ warn "foo" })'; /$c/;
- /(?{ warn "foo" })/;
-
-formerly gave:
-
- foo at (re_eval 1) line 1.
- foo at (re_eval 2) line 1.
-
-and now gives:
-
- foo at (eval 1) line 1.
- foo at /some/prog line 2.
+Subroutine redefinitions after sub-to-glob and glob-to-glob assignments no
+longer cause double frees or panic messages.
=back
-=item *
-
-Perl now works as well as can be expected on all releases of Unicode so
-far. In v5.16, it worked on Unicodes 6.0 and 6.1, but there were
-various bugs for earlier releases; the older the release the more
-problems.
-
-=item *
-
-C<vec> no longer produces "uninitialized" warnings in lvalue context
-[perl #9423].
-
-=item *
-
-An optimisation involving fixed strings in regular expressions could cause
-a severe performance penalty in edge cases. This has been fixed
-[perl #76546].
-
-=item *
-
-In certain cases, including empty subpatterns within a regular expression (such
-as C<(?:)> or C<(?:|)>) could disable some optimizations. This has been fixed.
-
-=item *
-
-The "Can't find an opnumber" message that C<prototype> produces when passed
-a string like "CORE::nonexistent_keyword" now passes UTF8 and embedded
-NULs through unchanged [perl #97478].
-
-=item *
-
-C<prototype> now treats magical variables like C<$1> the same way as
-non-magical variables when checking for the CORE:: prefix, instead of
-treating them as subroutine names.
-
-=item *
-
-Under threaded perls, a runtime code block in a regular expression could
-corrupt the package name stored in the op tree, resulting in bad reads
-in C<caller>, and possibly crashes [perl #113060].
-
-=item *
-
-Referencing a closure prototype (C<\&{$_[1]}> in an attribute handler for a
-closure) no longer results in a copy of the subroutine (or assertion
-failures on debugging builds).
-
-=item *
-
-C<eval '__PACKAGE__'> now returns the right answer on threaded builds if
-the current package has been assigned over (as in
-C<*ThisPackage:: = *ThatPackage::>) [perl #78742].
-
-=item *
-
-If a package is deleted by code that it calls, it is possible for C<caller>
-to see a stack frame belonging to that deleted package. C<caller> could
-crash if the stash's memory address was reused for a scalar and a
-substitution was performed on the same scalar [perl #113486].
-
-=item *
-
-C<UNIVERSAL::can> no longer treats its first argument differently
-depending on whether it is a string or number internally.
-
-=item *
-
-C<open> with "<&" for the mode checks to see whether the third argument is
-a number, in determining whether to treat it as a file descriptor or a
-handle name. Magical variables like C<$1> were always failing the numeric
-check and being treated as handle names.
-
-=item *
-
-C<warn>'s handling of magical variables (C<$1>, ties) has undergone several
-fixes. FETCH is only called once now on a tied argument or a tied C<$@>
-[perl #97480]. Tied variables returning objects that stringify as "" are
-no longer ignored. A tied C<$@> that happened to return a reference the
-I<previous> time is was used is no longer ignored.
-
-=item *
-
-C<warn ""> now treats C<$@> with a number in it the same way, regardless of
-whether it happened via C<$@=3> or C<$@="3">. It used to ignore the
-former. Now it appends "\t...caught", as it has always done with
-C<$@="3">.
-
-=item *
-
-Numeric operators on magical variables (e.g., S<C<$1 + 1>>) used to use
-floating point operations even where integer operations were more appropriate,
-resulting in loss of accuracy on 64-bit platforms [perl #109542].
-
-=item *
-
-Unary negation no longer treats a string as a number if the string happened
-to be used as a number at some point. So, if C<$x> contains the string "dogs",
-C<-$x> returns "-dogs" even if C<$y=0+$x> has happened at some point.
-
-=item *
-
-In Perl 5.14, C<-'-10'> was fixed to return "10", not "+10". But magical
-variables (C<$1>, ties) were not fixed till now [perl #57706].
-
-=item *
-
-Unary negation now treats strings consistently, regardless of the internal
-UTF8 flag.
-
-=item *
-
-A regression introduced in Perl v5.16.0 involving
-C<tr/I<SEARCHLIST>/I<REPLACEMENTLIST>/> has been fixed. Only the first
-instance is supposed to be meaningful if a character appears more than
-once in C<I<SEARCHLIST>>. Under some circumstances, the final instance
-was overriding all earlier ones. [perl #113584]
-
-=item *
-
-Regular expressions like C<qr/\87/> previously silently inserted a NUL
-character, thus matching as if it had been written C<qr/\00087/>. Now it
-matches as if it had been written as C<qr/87/>, with a message that the
-sequence C<"\8"> is unrecognized.
-
-=item *
-
-C<__SUB__> now works in special blocks (BEGIN, END, etc.).
-
-=item *
-
-Thread creation on Windows could theoretically result in a crash if done
-inside a BEGIN block. It still does not work properly, but it no longer
-crashes [perl #111610].
-
-=item *
-
-C<\&{''}> (with the empty string) now autovivifies a stub like any other
-sub name, and no longer produces the "Unable to create sub" error
-[perl #94476].
+=head1 Known Problems
-=back
+XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
+tests that had to be C<TODO>ed for the release would be noted here. Unfixed
+platform specific bugs also go here.
-=head1 Known Problems
+[ List each fix as a =item entry ]
=over 4
=item *
-On VMS, Module::Build still fails its test suite.
+XXX
-=item *
+=back
-On Win32, several tests fail intermittently, and may hang unless STDERR is
-redirected.
+=head1 Obituary
-=back
+XXX If any significant core contributor has died, we've added a short obituary
+here.
=head1 Acknowledgements
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.17.0..HEAD
+ perl Porting/acknowledgements.pl v5.17.2..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff