cmd/gc: fix internal compiler error in struct compare

Fixes issue 9006.

LGTM=r
R=r
CC=golang-codereviews
https://codereview.appspot.com/167800043

1 files changed, 37 insertions, 0 deletions

diff --git a/test/fixedbugs/issue9006.go b/test/fixedbugs/issue9006.go
new file mode 100644
index 000000000..c559f58f1
--- /dev/null
+++ b/test/fixedbugs/issue9006.go
@@ -0,0 +1,37 @@
+// run
+
+// Copyright 2014 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.
+
+package main
+
+type T1 struct {
+	X int
+}
+
+func NewT1(x int) T1 { return T1{x} }
+
+type T2 int
+
+func NewT2(x int) T2 { return T2(x) }
+
+func main() {
+	switch (T1{}) {
+	case NewT1(1):
+		panic("bad1")
+	case NewT1(0):
+		// ok
+	default:
+		panic("bad2")
+	}
+
+	switch T2(0) {
+	case NewT2(2):
+		panic("bad3")
+	case NewT2(0):
+		// ok
+	default:
+		panic("bad4")
+	}
+}