add test for yesterday's interface rule change (interface/convert1.go).

move interface tests to subdirectory.

R=r
DELTA=1632  (827 added, 804 deleted, 1 changed)
OCL=29181
CL=29191

1 files changed, 34 insertions, 0 deletions

diff --git a/test/interface/explicit.go b/test/interface/explicit.go
new file mode 100644
index 000000000..3b5ed01ca
--- /dev/null
+++ b/test/interface/explicit.go
@@ -0,0 +1,34 @@
+// errchk $G $D/$F.go
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Static error messages about interface conversions.
+
+package main
+
+type T struct { a int }
+var t *T
+
+type I interface { M() }
+var i I
+
+type I2 interface { M(); N(); }
+var i2 I2;
+
+var e interface { };
+
+func main() {
+	e = t;	// ok
+	t = e;	// ERROR "need explicit"
+
+	// neither of these can work,
+	// because i has an extra method
+	// that t does not, so i cannot contain a t.
+	i = t;	// ERROR "missing|incompatible|is not"
+	t = i;	// ERROR "missing|incompatible|is not"
+
+	i = i2;	// ok
+	i2 = i;	// ERROR "need explicit"
+}