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.
=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
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
=head1 Utility Changes
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
=head1 Known Problems
https://perl5.git.perl.org / perl5.git / blobdiff