Remove compile-time checking of rv2?v with const kid

There was code in op.c:ck_rvconst (which runs when creating a derefer-
ence op, such as rv2sv, rv2av, etc.) that would check that a constant
kid holding a reference pointed to something of the right type.  It
failed to take overloading into account.

The result was that these lines would fail to compile:

    constant_reference_to_hash_with_coderef_overloading->();
    constant_reference_to_sub_with_hashref_overloading->{key};
    constant_reference_to_sub_with_arrayref_overloading->[0];
    constant_reference_to_sub_with_scalarref_overloading->$*;

even though they should work.

Since the overloadedness could change any time, even checking for that
in op.c is incorrect.  The only correct fix is to remove this compile-
time check.  If something naughty gets through, it will be caught
at run time.

This fixes bugs #122607 and #69456.

1 files changed, 18 insertions, 1 deletions

diff --git a/lib/overload.t b/lib/overload.t
index d89ec2a510..2371c71a3f 100644
--- a/lib/overload.t
+++ b/lib/overload.t
@@ -48,7 +48,7 @@ package main;
 
 $| = 1;
 BEGIN { require './test.pl' }
-plan tests => 5194;
+plan tests => 5198;
 
 use Scalar::Util qw(tainted);
 
@@ -2730,6 +2730,23 @@ EOF
     pass("RT 121362");
 }
 
+package refsgalore {
+    use overload
+	'${}' => sub { \42  },
+	'@{}' => sub { [43] },
+	'%{}' => sub { { 44 => 45 } },
+	'&{}' => sub { sub { 46 } };
+}
+{
+    use feature 'postderef';
+    no warnings 'experimental::postderef';
+    tell myio; # vivifies *myio{IO} at compile time
+    use constant ioref => bless *myio{IO}, refsgalore::;
+    is ioref->$*, 42, '(overloaded constant that is not a scalar ref)->$*';
+    is ioref->[0], 43, '(ovrld constant that is not an array ref)->[0]';
+    is ioref->{44}, 45, "(ovrld const that is not a hash ref)->{key}";
+    is ioref->(), 46, '(overloaded constant that is not a sub ref)->()';
+}
 
 { # undefining the overload stash -- KEEP THIS TEST LAST
     package ant;