test: add test for invalid nil == nil
R=gri
CC=golang-dev
https://golang.org/cl/6868059
diff --git a/test/fixedbugs/issue4283.go b/test/fixedbugs/issue4283.go
new file mode 100644
index 0000000..128c872
--- /dev/null
+++ b/test/fixedbugs/issue4283.go
@@ -0,0 +1,17 @@
+// errorcheck
+
+// Copyright 2012 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.
+
+// Issue 4283: nil == nil can't be done as the type is unknown.
+
+package p
+
+func F1() bool {
+ return nil == nil // ERROR "invalid"
+}
+
+func F2() bool {
+ return nil != nil // ERROR "invalid"
+}
