[ 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 v5.21.1
+perldelta - what is new for perl v5.21.4
=head1 DESCRIPTION
-This document describes differences between the 5.21.0 release and the 5.21.1
+This document describes differences between the 5.21.3 release and the 5.21.4
release.
-If you are upgrading from an earlier release such as 5.20.0, first read
-L<perl5210delta>, which describes differences between 5.20.0 and 5.21.0.
+If you are upgrading from an earlier release such as 5.21.2, first read
+L<perl5213delta>, which describes differences between 5.21.2 and 5.21.3.
=head1 Notice
[ List each enhancement as a =head2 entry ]
-=head2 Unicode 7.0 is now supported
+=head2 Infinity and NaN (not-a-number) handling improved
-For details on what is in this release, see
-L<http://www.unicode.org/versions/Unicode7.0.0/>.
+Floating point values are able to hold the special values infinity
+(also -infinity), and NaN (not-a-number). Now we more robustly recognize
+and propagate the value in computations, and on output normalize them
+to C<Inf> and C<NaN>.
-=head2 Experimental C Backtrace API
-
-Starting from Perl 5.21.1, on some platforms Perl supports retrieving
-the C level backtrace (similar to what symbolic debuggers like gdb do).
-
-The backtrace returns the stack trace of the C call frames,
-with the symbol names (function names), the object names (like "perl"),
-and if it can, also the source code locations (file:line).
-
-The supported platforms are Linux and OS X (some *BSD might work at
-least partly, but they have not yet been tested).
-
-The feature needs to be enabled with C<Configure -Dusecbacktrace>.
-
-Also included is a C API to retrieve backtraces.
-
-See L<perlhacktips/"C backtrace"> for more information.
-
-=head2 C<qr/foo/x> now ignores any Unicode pattern white space
-
-The C</x> regular expression modifier allows the pattern to contain
-white space and comments, both of which are ignored, for improved
-readability. Until now, not all the white space characters that Unicode
-designates for this purpose were handled. The additional ones now
-recognized are
-U+0085 NEXT LINE,
-U+200E LEFT-TO-RIGHT MARK,
-U+200F RIGHT-TO-LEFT MARK,
-U+2028 LINE SEPARATOR,
-and
-U+2029 PARAGRAPH SEPARATOR.
-
-=head2 S<C<use locale>> can restrict which locale categories are affected
-
-It is now possible to pass a parameter to S<C<use locale>> to specify
-a subset of locale categories to be locale-aware, with the remaining
-ones unaffected. See L<perllocale/The "use locale" pragma> for details.
+See also the L<POSIX> enhancements.
=head1 Security
If any exist, they are bugs, and we request that you submit a
report. See L</Reporting Bugs> below.
-=head2 S<C<"use encoding">> now is a fatal error
-
-The C<encoding> pragma has been deprecated since v5.18, and its use now
-is a fatal error.
-
-=head2 C<\N{}> with a sequence of multiple spaces is now a fatal error.
-
-This has been deprecated since v5.18.
-
-=head2 In double-quotish C<\cI<X>>, I<X> must now be a printable ASCII character
-
-In prior releases, failure to do this raised a deprecation warning.
+[ List each incompatible change as a =head2 entry ]
-=head2 Splitting the tokens C<(?> and C<(*> in regular expressions is
-now a fatal compilation error.
+=head2 Changes to the C<*> prototype
-These had been deprecated since v5.18.
+The C<*> character in a subroutine's prototype used to allow barewords
+to take precedence over most, but not all subroutines. It was never
+consistent and exhibited buggy behaviour.
-=head2 5 additional characters are treated as white space under C</x> in
-regex patterns (unless escaped)
+Now it has been changed, so subroutines always take precedence over
+barewords, which brings it into conformity with similarly prototyped
+built-in functions:
-The use of these characters with C</x> outside bracketed character
-classes and when not preceeded by a backslash has raised a deprecation
-warning since v5.18. Now they will be ignored. See L</qrE<sol>fooE<sol>x>
-for the list of the five characters.
-
-=head2 Comment lines within S<C<(?[ ])>> now are ended only by a C<\n>
-
-S<C<(?[ ])>> is an experimental feature, introduced in v5.18. It operates
-as if C</x> is always enabled. But there was a difference, comment
-lines (following a C<#> character) were terminated by anything matching
-C<\R> which includes all vertical whitespace, such as form feeds. For
-consistency, this is now changed to match what terminates comment lines
-outside S<C<(?[ ])>>, namely a C<\n> (even if escaped), which is the
-same as what terminates a heredoc string and formats.
-
-=head2 Omitting % and @ on hash and array names is no longer permitted
-
-Really old Perl let you omit the @ on array names and the % on hash
-names in some spots. This has issued a deprecation warning since Perl
-5.0, and is no longer permitted.
-
-=head2 C<"$!"> text is now in English outside C<"use locale"> scope
-
-Previously, the text, unlike almost everything else, always came out
-based on the current underlying locale of the program. (Also affected
-on some systems is C<"$^E>".) For programs that are unprepared to
-handle locale, this can cause garbage text to be displayed. It's better
-to display text that is translatable via some tool than garbage text
-which is much harder to figure out.
-
-=head2 C<"$!"> text will be returned in UTF-8 when appropriate
-
-The stringification of C<$!> and C<$^E> will have the UTF-8 flag set
-when the text is actually non-ASCII UTF-8. This will enable programs
-that are set up to be locale-aware to properly output messages in the
-user's native language. Code that needs to continue the 5.20 and
-earlier behavior can do the stringification within the scopes of both
-'use bytes' and 'use locale ":messages". No other Perl operations will
-be affected by locale; only C<$!> and C<$^E> stringification. The
-'bytes' pragma causes the UTF-8 flag to not be set, just as in previous
-Perl releases. This resolves [perl #112208].
-
-=head2 MAD build option has been removed
-
-MAD = Misc Attribute Decoration; unmaintained attempt at preserving
-the Perl parse tree more faithfully so that automatic conversion of
-Perl 5 to Perl 6 would have been easier.
-
-This build-time configuration option had been unmaintained for years,
-and had probably seriously diverged on both Perl 5 and Perl 6 sides.
-
-=head2 Support for C<?PATTERN?> without explicit operator has been removed
-
-Starting regular expressions matching only once directly with the
-question mark delimiter is now a syntax error, so that the question mark
-can be available for use in new operators. Write C<m?PATTERN?> instead,
-explicitly using the C<m> operator: the question mark delimiter still
-invokes match-once behaviour.
+ sub splat($) { ... }
+ sub foo { ... }
+ splat(foo); # now always splat(foo())
+ splat(bar); # still splat('bar') as before
+ close(foo); # close(foo())
+ close(bar); # close('bar')
=head1 Deprecations
XXX Any deprecated features, syntax, modules etc. should be listed here.
-=head2 Using a NO-BREAK space in a character alias for C<\N{...}> is now
-deprecated
-
-This non-graphic character is essentially indistinguishable from a
-regular space, and so should not be allowed. See
-L<charnames/CUSTOM ALIASES>.
-
-=head2 A literal C<"{"> should now be escaped in a pattern
-
-If you want a literal left curly bracket (also called a left brace) in a
-regular expression pattern, you should now escape it by either
-preceding it with a backslash (C<"\{">) or enclosing it within square
-brackets C<"[{]">, or by using C<\Q>; otherwise a deprecation warning
-will be raised. This was first announced as forthcoming in the v5.16
-release; it will allow future extensions to the language to happen.
-
=head2 Module removals
XXX Remove this section if inapplicable.
=item *
-Many internal functions have been refactored to improve performance and reduce
-their memory footprints.
-
-L<[perl #121436]|https://rt.perl.org/Ticket/Display.html?id=121436>
-L<[perl #121906]|https://rt.perl.org/Ticket/Display.html?id=121906>
-L<[perl #121969]|https://rt.perl.org/Ticket/Display.html?id=121969>
-
-=item *
-
-C<-T> and C<-B> filetests will return sooner when an empty file is detected.
-
-L<perl #121489|https://rt.perl.org/Ticket/Display.html?id=121489>
+Subroutines with an empty prototype and bodies containing just C<undef> are
+now eligible for inlining. [perl #122728]
=back
=item *
-L<Carp> has been upgraded from version 1.3301 to 1.34.
-
-Carp::Heavy now ignores version mismatches with Carp if Carp is newer
-than 1.12, since Carp::Heavy's guts were merged into Carp at that
-point.
-L<[perl #121574]|https://rt.perl.org/Ticket/Display.html?id=121574>
+L<XXX> has been upgraded from version A.xx to B.yy.
=item *
-L<Data::Dumper> has been upgraded from version 2.151 to 2.152.
-
-Changes to resolve Coverity issues.
-
-XS dumps incorrectly stored the name of code references stored in a
-GLOB.
-L<[perl #122070]|https://rt.perl.org/Ticket/Display.html?id=122070>
+L<B::Concise> has been upgraded from version 0.992 to 0.993.
=item *
-L<Encode> has been upgraded from version 2.60_01 to 2.62.
-
-B<piconv> now has better error handling when the encoding name is nonexistent,
-and a build breakage when upgrading L<Encode> in perl-5.8.2 and earlier has
-been fixed.
+L<CPAN::Meta::Requirements> has been upgraded from version 2.126 to 2.128.
=item *
-L<Hash::Util> has been upgraded from version 0.16 to 0.17.
-
-Minor bug fixes and documentation fixes to Hash::Util::hash_stats()
+L<ExtUtils::CBuilder> has been upgraded from version 0.280216 to 0.280219.
+[perl #122675].
=item *
-The libnet collection of modules has been upgraded from version 1.25 to 1.27.
-
-There are only whitespace changes to the installed files.
+L<ExtUtils::Manifest> has been upgraded from version 1.65 to 1.66.
+[perl #122415].
=item *
-The Locale-Codes collection of modules has been upgraded from vesion 3.30 to 3.31.
-
-Fixed a bug in the scripts used to extract data from spreadsheets that
-prevented the SHP currency code from being found.
-L<[cpan #94229]|https://rt.cpan.org/Ticket/Display.html?id=94229>
+L<ExtUtils::ParseXS>: Documentation has been added to
+F<ExtUtils-ParseXS/lib/perlxs.pod> concerning handling of locales when writing
+XS code.
=item *
-L<Math::BigInt> has been upgraded from version 1.9993 to 1.9994.
+L<File::Find> has been upgraded from version 1.27 to 1.28.
-Synchronize POD changes from the CPAN release.
-
-C<< Math::BigFloat->blog(x) >> would sometimes return blog(2*x) when
-the accuracy was greater than 70 digits.
-
-The result of C<< Math::BigFloat->bdiv() >> in list context now
-satisfies C<< x = quotient * divisor + remainder >>.
-
-=item *
-
-L<Math::BigRat> has been upgraded from version 0.2606 to 0.2607.
-
-Synchronize POD changes from the CPAN release.
-
-=item *
-
-L<Module::Metadata> has been upgraded from version 1.000022 to 1.000024.
-
-Support installations on older perls with an L<ExtUtils::MakeMaker> earlier
-than 6.63_03
+C<find()> and C<finddepth()> will now warn if passed inappropriate or
+misspelled options.
=item *
-L<OS2::Process> has been upgraded from version 1.09 to 1.10.
+L<Getopt::Std> has been upgraded from version 1.10 to 1.11.
=item *
-L<perl5db.pl> has been upgraded from version 1.44 to 1.45.
-
-fork() in the debugger under C<tmux> will now create a new window for
-the forked process. L<[perl
-#121333]|https://rt.perl.org/Ticket/Display.html?id=121333>
-
-The debugger now saves the current working directory on startup and
-restores it when you restart your program with C<R> or <rerun>. L<[perl
-#121509]|https://rt.perl.org/Ticket/Display.html?id=121509>
+L<HTTP::Tiny> has been upgraded from version 0.047 to 0.048.
=item *
-L<PerlIO::encoding> has been upgraded from version 0.18 to 0.19.
-
-No changes in behaviour.
+L<Module::CoreList> has been upgraded from version 5.021003 to 5.021004.
=item *
-L<PerlIO::mmap> has been upgraded from version 0.012 to 0.013.
+L<POSIX> has been upgraded from version 1.42 to 1.43.
-No changes in behaviour.
+The C99 math functions and constants (for example acosh, round,
+M_E, M_PI) have been added.
=item *
-L<PerlIO::scalar> has been upgraded from version 0.18 to 0.19.
-
-No changes in behaviour.
+L<Pod::Perldoc> has been upgraded from version 3.23 to 3.24.
=item *
-L<Unicode::Collate> has been upgraded from version 1.04 to 1.07.
-
-Version 0.67's improved discontiguous contractions is invalidated by default
-and is supported as a parameter 'long_contraction'.
+Scalar-List-Utils has been upgraded from version 1.40 to 1.41.
=item *
-L<Unicode::Normalize> has been upgraded from version 1.17 to 1.18.
+L<constant> has been upgraded from version 1.31 to 1.32.
-The XSUB implementation has been removed in favour of pure Perl.
+It now accepts fully-qualified constant names, allowing constants to be
+defined in packages other than the caller.
=item *
-A mismatch between the documentation and the code in utf8::downgrade()
-was fixed in favour of the documentation. The optional second argument
-is now correctly treated as a perl boolean (true/false semantics) and
-not as an integer.
+L<threads> has been upgraded from version 1.95 to 1.96.
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<perlfunc>
-
-=over 4
-
-=item *
-
-C<-l> now notes that it will return false if symlinks aren't supported by the
-file system.
-
-L<[perl #121523]|https://rt.perl.org/Ticket/Display.html?id=121523>
-
-=item *
-
-Note that C<exec LIST> and C<system LIST> may fall back to the shell on
-Win32. Only C<exec PROGRAM LIST> and C<system PROGRAM LIST> indirect object
-syntax will reliably avoid using the shell.
-
-This has also been noted in L<perlport>.
-
-L<[perl #122046]|https://rt.perl.org/Ticket/Display.html?id=122046>
-
-=back
-
-=head3 L<perlapi>
-
-=over 4
-
-=item *
-
-Note that C<SvSetSV> doesn't do set magic.
-
-=item *
-
-C<sv_usepvn_flags> - Fix documentation to mention the use of C<NewX> instead of
-C<malloc>.
-
-L<[perl #121869]|https://rt.perl.org/Ticket/Display.html?id=121869>
-
-=item *
-
-Clarify where C<NUL> may be embedded or is required to terminate a string.
-
-=item *
-
-Previously missing documentation due to formatting errors are now included.
-
-=item *
-
-Entries are now organized into groups rather than by file where they are found.
-
-=item *
-
-Alphabetical sorting of entries is now handled by the POD generator to make
-entries easier to find when scanning.
-
-=back
-
-=head3 L<perlhacktips>
-
-=over 4
-
-=item *
-
-Updated documentation for the C<test.valgrind> C<make> target.
-
-L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
-
-=back
-
-=head3 L<perlre>
+=head3 L<XXX>
=over 4
=item *
-The C</x> modifier has been clarified to note that comments cannot be continued
-onto the next line by escaping them.
-
-=back
-
-=head3 L<Unicode::UCD>
-
-=over 4
+XXX Description of the change here
=item *
-The documentation includes many clarifications and fixes.
+L<perlsyn>: An ambiguity in the documentation of the Ellipsis statement has
+been corrected. [perl #122661]
=back
=item *
-L<In '(?...)', the '(' and '?' must be adjacent in regex; marked by S<<-- HERE> in mE<sol>%sE<sol>|perldiag/"In '(?...)', the '(' and '?' must be adjacent in regex; marked by <-- HERE in m/%s/">
-
-(F) The two-character sequence C<"(?"> in
-this context in a regular expression pattern should be an
-indivisible token, with nothing intervening between the C<"(">
-and the C<"?">, but you separated them.
-
-=item *
-
-L<In '(*VERB...)', the '(' and '*' must be adjacent in regex; marked by S<<-- HERE> in mE<sol>%sE<sol>|perldiag/"In '(*VERB...)', the '(' and '*' must be adjacent in regex; marked by <-- HERE in m/%s/">
-
-(F) The two-character sequence C<"(*"> in
-this context in a regular expression pattern should be an
-indivisible token, with nothing intervening between the C<"(">
-and the C<"*">, but you separated them.
-
-=item *
-
-L<charnames alias definitions may not contain a sequence of multiple spaces|perldiag/"charnames alias definitions may not contain a sequence of multiple spaces">
-
-(F) You defined a character name which had multiple space
- characters in a row. Change them to single spaces. Usually these
- names are defined in the C<:alias> import argument to C<use charnames>, but
- they could be defined by a translator installed into C<$^H{charnames}>.
- See L<charnames/CUSTOM ALIASES>.
-
-=item *
-
-L<charnames alias definitions may not contain trailing white-space|perldiag/"charnames alias definitions may not contain trailing white-space">
-
-(F) You defined a character name which ended in a space
-character. Remove the trailing space(s). Usually these names are
-defined in the C<:alias> import argument to C<use charnames>, but they
-could be defined by a translator installed into C<$^H{charnames}>.
-See L<charnames/CUSTOM ALIASES>.
-
-=item *
-
-L<Can't use a hash as a reference|perldiag/"Can't use a hash as a reference">
-
-(F) You tried to use a hash as a reference, as in
-C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
-used to allow this syntax, but shouldn't have.
-
-=item *
-
-L<Can't use an array as a reference|perldiag/"Can't use an array as a reference">
-
-(F) You tried to use an array as a reference, as in
-C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.6.1 used to
-allow this syntax, but shouldn't have.
-
-=item *
-
-L<Can't use 'defined(@array)' (Maybe you should just omit the defined()?)|perldiag/"Can't use 'defined(@array)' (Maybe you should just omit the defined()?)">
-
-(F) defined() is not useful on arrays because it
-checks for an undefined I<scalar> value. If you want to see if the
-array is empty, just use C<if (@array) { # not empty }> for example.
-
-=item *
-
-L<Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)|perldiag/"Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)">
-
-(F) C<defined()> is not usually right on hashes.
-
-Although C<defined %hash> is false on a plain not-yet-used hash, it
-becomes true in several non-obvious circumstances, including iterators,
-weak references, stash names, even remaining true after C<undef %hash>.
-These things make C<defined %hash> fairly useless in practice, so it now
-generates a fatal error.
-
-If a check for non-empty is what you wanted then just put it in boolean
-context (see L<perldata/Scalar values>):
-
- if (%hash) {
- # not empty
- }
-
-If you had C<defined %Foo::Bar::QUUX> to check whether such a package
-variable exists then that's never really been reliable, and isn't
-a good way to enquire about the features of a package, or whether
-it's loaded, etc.
-
-=item *
-
-L<Illegal suidscript|perldiag/"Illegal suidscript">
-
-(F) The script run under suidperl was somehow illegal.
+XXX L<message|perldiag/"message">
=back
=item *
-L<Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in mE<sol>%sE<sol>|perldiag/"Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in m/%s/">
-
-(D deprecated, regexp) You used a literal C<"{"> character in a regular
-expression pattern. You should change to use C<"\{"> instead, because a future
-version of Perl (tentatively v5.26) will consider this to be a syntax error. If
-the pattern delimiters are also braces, any matching right brace
-(C<"}">) should also be escaped to avoid confusing the parser, for
-example,
-
- qr{abc\{def\}ghi}
-
-=item *
-
-L<NO-BREAK SPACE in a charnames alias definition is deprecated|perldiag/"NO-BREAK SPACE in a charnames alias definition is deprecated">
-
-(D deprecated) You defined a character name which contained a no-break
-space character. Change it to a regular space. Usually these names are
-defined in the C<:alias> import argument to C<use charnames>, but they
-could be defined by a translator installed into C<$^H{charnames}>. See
-L<charnames/CUSTOM ALIASES>.
-
-=item *
-
-L<PerlIO layer ':win32' is experimental|perldiag/"PerlIO layer ':win32' is experimental">
-
-(S experimental::win32_perlio) The C<:win32> PerlIO layer is
-experimental. If you want to take the risk of using this layer,
-simply disable this warning:
-
- no warnings "experimental::win32_perlio";
+XXX L<message|perldiag/"message">
-=item *
-
-L<Negative repeat count does nothing|perldiag/"Negative repeat count does nothing">
-
-(W numeric) You tried to execute the
-L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
-times, which doesn't make sense.
-
-=item *
-
-L<localtime(%f) failed|perldiag/"localtime(%f) failed">
-
-(W overflow) You called C<localtime> with a number that it could not handle:
-too large, too small, or NaN. The returned value is C<undef>.
-
-=item *
-
-L<gmtime(%f) failed|perldiag/"gmtime(%f) failed">
-
-(W overflow) You called C<gmtime> with a number that it could not handle:
-too large, too small, or NaN. The returned value is C<undef>.
-
-=item *
+=back
-L<PerlIO layer ':win32' is experimental|perldiag/"PerlIO layer ':win32' is experimental">:
+=head2 Changes to Existing Diagnostics
-(S experimental::win32_perlio) The C<:win32> PerlIO layer is
-experimental. If you want to take the risk of using this layer,
-simply disable this warning:
+XXX Changes (i.e. rewording) of diagnostic messages go here
- no warnings "experimental::win32_perlio";
+=over 4
=item *
-L<Negative repeat count does nothing|perldiag/Negative repeat count does nothing>
-
-(W numeric) This warns when the repeat count of the
-L<C<x>|perlop/Multiplicative Operators> repetition operator is
-negative.
-
-This warning may be changed or removed if it turn out that it was
-unwise to have added it.
+XXX Describe change here
=back
-=head2 Changes to Existing Diagnostics
-
-XXX Changes (i.e. rewording) of diagnostic messages go here
+=head2 Diagnostic Removals
=over 4
=item *
-L<Variable length lookbehind not implemented in regex mE<sol>%sE<sol>|perldiag/"Variable length lookbehind not implemented in regex m/%s/">
+"Constant is not a FOO reference"
-Information about Unicode behaviour has been added.
+Compile-time checking of constant dereferencing (e.g.,
+C<< my_constant->() >>) has been removed, since it was not taking
+overloading into account. [perl #69456] [perl #122607]
=item *
-<> should be quotes
-
-This warning has been changed to
-L<< <> at require-statement should be quotes|perldiag/"<> at require-statement should be quotes" >>
-to make the issue more identifiable.
+The warning "Ambiguous use of -foo resolved as -&foo()" has been removed.
+There is actually no ambiguity here, and this impedes the use of negated
+constants; e.g., C<-Inf>.
=item *
-L<Unsuccessful %s on filename containing newline|perldiag/"Unsuccessful %s on filename containing newline">
-
-This warning is now only produced when the newline is at the end of
-the filename.
+The little-known C<my Class $var> syntax (see L<fields> and L<attributes>)
+could get confused in the scope of C<use utf8> if C<Class> were a constant
+whose value contained Latin-1 characters.
=back
entries for each change
Use L<XXX> with program names to get proper documentation linking. ]
-=head2 F<x2p/>
+=head2 L<XXX>
=over 4
=item *
-The F<x2p/> directory has been removed from the Perl core.
-
-This removes find2perl, s2p and a2p. They have all been released to CPAN as
-separate distributions (App::find2perl, App::s2p, App::a2p).
+XXX
=back
=item *
-C<make test.valgrind> now supports parallel testing.
-
-For example:
-
- TEST_JOBS=9 make test.valgrind
-
-See L<perlhacktips/valgrind> for more information.
-
-L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
+XXX
=back
=over 4
-=item NeXTSTEP/OPENSTEP
+=item XXX-some-platform
-NeXTSTEP was proprietary OS bundled with NeXT's workstations in the early
-to mid 90's; OPENSTEP was an API specification that provided a NeXTSTEP-like
-environment on a non-NeXTSTEP system. Both are now long dead, so support
-for building Perl on them has been removed.
+XXX
=back
XXX
-=item OpenBSD
-
-On OpenBSD, Perl will now default to using the system C<malloc> due to the
-security features it provides. Perl's own malloc wrapper has been in use
-since v5.14 due to performance reasons, but the OpenBSD project believes
-the tradeoff is worth it and would prefer that users who need the speed
-specifically ask for it.
-
-L<[perl #122000]|https://rt.perl.org/Ticket/Display.html?id=122000>.
-
=back
=head1 Internal Changes
significant internal changes for future core maintainers should be noted as
well.
+[ List each change as a =item entry ]
+
+=over 4
+
+C<save_re_context> no longer does anything and has been moved to
+F<mathoms.c>.
+
+=back
+
+=head1 Selected Bug Fixes
+
+XXX Important bug fixes in the core language are summarized here. Bug fixes in
+files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
+
+[ List each fix as a =item entry ]
+
=over 4
=item *
-The deprecated variable C<PL_sv_objcount> has been removed.
+XXX
=item *
-Perl now tries to keep the locale category C<LC_NUMERIC> set to "C"
-except around operations that need it to be set to the program's
-underlying locale. This protects the many XS modules that cannot cope
-with the decimal radix character not being a dot. Prior to this
-release, Perl initialized this category to "C", but a call to
-C<POSIX::setlocale()> would change it. Now such a call will change the
-underlying locale of the C<LC_NUMERIC> category for the program, but the
-locale exposed to XS code will remain "C". There is an API under
-development for those relatively few modules that need to use the
-underlying locale. This API will be nailed down during the course of
-developing v5.21. Send email to L<mailto:perl5-porters@perl.org> for
-guidance.
+Constant dereferencing now works correctly for typeglob constants.
+Previously the glob was stringified and its name looked up. Now the glob
+itself is used. [perl #69456]
=item *
-A new macro L<C<isUTF8_CHAR>|perlapi/isUTF8_CHAR> has been written which
-efficiently determines if the string given by its parameters begins
-with a well-formed UTF-8 encoded character.
+When parsing a funny character ($ @ % &) followed by braces, the parser no
+longer tries to guess whether it is a block or a hash constructor (causing
+a syntax error when it guesses the latter), since it can only be a block.
-=back
+=item *
-=head1 Selected Bug Fixes
+C<undef $reference> now frees the referent immediately, instead of hanging
+on to it until the next statement. [perl #122556]
-XXX Important bug fixes in the core language are summarized here. Bug fixes in
-files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
+=item *
-[ List each fix as a =item entry ]
+Various cases where the name of a sub is used (autoload, overloading, error
+messages) used to crash for lexical subs, but have been fixed.
-=over 4
+=item *
+
+Bareword lookup now tries to avoid vivifying packages if it turns out the
+bareword is not going to be a subroutine name.
+
+=item *
+
+Compilation of anonymous constants (e.g., C<sub () { 3 }>) no longer
+deletes any subroutine named C<__ANON__> in the current package. Not only
+was C<*__ANON__{CODE}> cleared, but there was a memory leak, too. This bug
+goes back to perl 5.8.0.
+
+=item *
+
+Stub declarations like C<sub f;> and C<sub f ();> no longer wipe out
+constants of the same name declared by C<use constant>. This bug was
+introduced in perl 5.10.0.
=item *
-index() and rindex() no longer crash when used on strings over 2GB in
-size.
-L<[perl #121562]|https://rt.perl.org/Ticket/Display.html?id=121562>.
+Under some conditions a warning raised in compilation of regular
+expression patterns could be displayed multiple times. This is now
+fixed.
=item *
-A small previously intentional memory leak in PERL_SYS_INIT/PERL_SYS_INIT3 on
-Win32 builds was fixed. This might affect embedders who repeatedly create and
-destroy perl engines within the same process.
+C<qr/[\N{named sequence}]/> now works properly in many instances. Some
+names known to C<\N{...}> refer to a sequence of multiple characters,
+instead of the usual single character. Bracketed character classes
+generally only match single characters, but now special handling has
+been added so that they can match named sequences, but not if the class
+is inverted or the sequence is specified as the beginning or end of a
+range. In these cases, the only behavior change from before is a slight
+rewording of the fatal error message given when this class is part of a
+C<?[...])> construct. When the C<[...]> stands alone, the same
+non-fatal warning as before is raised, and only the first character in
+the sequence is used, again just as before.
=item *
-C<POSIX::localeconv()> now returns the data for the program's underlying
-locale even when called from outside the scope of S<C<use locale>>.
+Tainted constants evaluated at compile time no longer cause unrelated
+statements to become tainted. [perl #122669]
=item *
-C<POSIX::localeconv()> now works properly on platforms which don't have
-C<LC_NUMERIC> and/or C<LC_MONETARY>, or for which Perl has been compiled
-to disregard either or both of these locale categories. In such
-circumstances, there are now no entries for the corresponding values in
-the hash returned by C<localeconv()>.
+C<open $$fh, ...>, which vivifies a handle with a name like "main::_GEN_0",
+was not giving the handle the right reference count, so a double free could
+happen.
=item *
-C<POSIX::localeconv()> now marks appropriately the values it returns as
-UTF-8 or not. Previously they were always returned as a bytes, even if
-they were supposed to be encoded as UTF-8.
+When deciding that a bareword was a method name, the parser would get
+confused if an "our" sub with the same name existed, and look up the method
+in the package of the "our" sub, instead of the package of the invocant.
=item *
-On Microsoft Windows, within the scope of C<S<use locale>>, the following
-POSIX character classes gave results for many locales that did not
-conform to the POSIX standard:
-C<[[:alnum:]]>,
-C<[[:alpha:]]>,
-C<[[:blank:]]>,
-C<[[:digit:]]>,
-C<[[:graph:]]>,
-C<[[:lower:]]>,
-C<[[:print:]]>,
-C<[[:punct:]]>,
-C<[[:upper:]]>,
-C<[[:word:]]>,
-and
-C<[[:xdigit:]]>.
-These are because the underlying Microsoft implementation does not
-follow the standard. Perl now takes special precautions to correct for
-this.
+The parser no longer gets confused by C<\U=> within a double-quoted string.
+It used to roduce a syntax error, but now compiles it correctly.
+[perl #80368]
=item *
-Many issues have been detected by L<Coverity|http://www.coverity.com/> and
+It has always been the intention for the C<-B> and C<-T> file test
+operators to treat UTF-8 encoded files as text.
+(L<perlfunc|perlfunc/-X FILEHANDLE> has been updated to say this.)
+Previously, it was possible for some files to be considered UTF-8 that
+actually weren't valid UTF-8. This is now fixed. The operators now
+work on EBCDIC platforms as well.
+
+=item *
+
+Under some conditions warning messages raised during regular expression
+pattern compilation were being output more than once. This has now been
fixed.
=item *
-system() and friends should now work properly on more Android builds.
+A regression has been fixed that was introduced in v5.20.0 (fixed in
+v5.20.1 as well as here) in which a UTF-8 encoded regular expression
+pattern that contains a single ASCII lowercase letter does not match its
+uppercase counterpart. [perl #122655]
+
+=item *
-Due to an oversight, the value specified through -Dtargetsh to Configure
-would end up being ignored by some of the build process. This caused perls
-cross-compiled for Android to end up with defective versions of system(),
-exec() and backticks: the commands would end up looking for C</bin/sh>
-instead of C</system/bin/sh>, and so would fail for the vast majority
-of devices, leaving C<$!> as C<ENOENT>.
+Constant folding could incorrectly suppress warnings if lexical warnings
+(C<use warnings> or C<no warnings>) were not in effect and C<$^W> were
+false at compile time and true at run time.
=item *
-C<qr(...\(...\)...)>,
-C<qr[...\[...\]...]>,
-and
-C<qr{...\{...\}...}>
-now work. Previously it was impossible to escape these three
-left-characters with a backslash within a regular expression pattern
-where otherwise they would be considered metacharacters, and the pattern
-opening delimiter was the character, and the closing delimiter was its
-mirror character.
+Loading UTF8 tables during a regular expression match could cause assertion
+failures under debugging builds if the previous match used the very same
+regular expression. [perl #122747]
=back
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.21.1..HEAD
+ perl Porting/acknowledgements.pl v5.21.3..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff