Patching magic from Inaba-san's keyboard: fix for [perl #8769]:

"scalar upgraded to UTF-8 as a side effect of quote-interpolation
when 'use encoding' is engaged"-- wasn't actually encoding's fault.

p4raw-id: //depot/perl@18764

1 files changed, 18 insertions, 1 deletions

diff --git a/t/op/concat.t b/t/op/concat.t
index 4813690d6b..c1a6e23e7e 100644
--- a/t/op/concat.t
+++ b/t/op/concat.t
@@ -18,7 +18,7 @@ sub ok {
     return $ok;
 }
 
-print "1..12\n";
+print "1..18\n";
 
 ($a, $b, $c) = qw(foo bar);
 
@@ -87,3 +87,20 @@ ok("$c$a$c" eq "foo",    "concatenate undef, fore and aft");
     eval{"\x{1234}$pi"};
     ok(!$@, "bug id 20001020.006, constant right");
 }
+
+sub beq { use bytes; $_[0] eq $_[1]; }
+
+{
+    # concat should not upgrade its arguments.
+    my($l, $r, $c);
+
+    ($l, $r, $c) = ("\x{101}", "\x{fe}", "\x{101}\x{fe}");
+    ok(beq($l.$r, $c), "concat utf8 and byte");
+    ok(beq($l, "\x{101}"), "right not changed after concat u+b");
+    ok(beq($r, "\x{fe}"), "left not changed after concat u+b");
+
+    ($l, $r, $c) = ("\x{fe}", "\x{101}", "\x{fe}\x{101}");
+    ok(beq($l.$r, $c), "concat byte and utf8");
+    ok(beq($l, "\x{fe}"), "right not changed after concat b+u");
+    ok(beq($r, "\x{101}"), "left not changed after concat b+u");
+}