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diff --git a/test/switch6.go b/test/switch6.go
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+// errorcheck
+
+// Copyright 2016 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.
+
+// Check the compiler's switch handling that happens
+// at typechecking time.
+// This must be separate from other checks,
+// because errors during typechecking
+// prevent other errors from being discovered.
+
+package main
+
+// Verify that type switch statements with impossible cases are detected by the compiler.
+func f0(e error) {
+	switch e.(type) {
+	case int: // ERROR "impossible type switch case: e \(type error\) cannot have dynamic type int \(missing Error method\)"
+	}
+}
+
+// Verify that the compiler rejects multiple default cases.
+func f1(e interface{}) {
+	switch e {
+	default:
+	default: // ERROR "multiple defaults in switch"
+	}
+	switch e.(type) {
+	default:
+	default: // ERROR "multiple defaults in switch"
+	}
+}
+
+type I interface {
+	Foo()
+}
+
+type X int
+
+func (*X) Foo() {}
+func f2() {
+	var i I
+	switch i.(type) {
+	case X: // ERROR "impossible type switch case: i \(type I\) cannot have dynamic type X \(Foo method has pointer receiver\)"
+	}
+}