do_vop() couldn't correctly handle surprises from UTF-8 overloading.

p4raw-id: //depot/perl@28029

1 files changed, 13 insertions, 2 deletions

diff --git a/t/uni/overload.t b/t/uni/overload.t
index ef61667448..ca63b44a27 100644
--- a/t/uni/overload.t
+++ b/t/uni/overload.t
@@ -7,12 +7,12 @@ BEGIN {
     }
 }
 
-use Test::More tests => 190;
+use Test::More tests => 202;
 
 package UTF8Toggle;
 use strict;
 
-use overload '""' => 'stringify';
+use overload '""' => 'stringify', fallback => 1;
 
 sub new {
     my $class = shift;
@@ -243,6 +243,17 @@ foreach my $b ($big, UTF8Toggle->new($big)) {
     }
 }
 
+my $bits = "\311";
+foreach my $pieces ($bits, UTF8Toggle->new($bits)) {
+    like ($bits ^ $pieces, qr/\A\0+\z/, "something xor itself is zeros");
+    like ($bits ^ $pieces, qr/\A\0+\z/, "something xor itself is zeros");
+    like ($bits ^ $pieces, qr/\A\0+\z/, "something xor itself is zeros");
+
+    like ($pieces ^ $bits, qr/\A\0+\z/, "something xor itself is zeros");
+    like ($pieces ^ $bits, qr/\A\0+\z/, "something xor itself is zeros");
+    like ($pieces ^ $bits, qr/\A\0+\z/, "something xor itself is zeros");
+}
+
 END {
     1 while -f $tmpfile and unlink $tmpfile || die "unlink '$tmpfile': $!";
 }