bug324.go: test case for issue 1550

Also: renamed fixedbugs/bug322.go to fixedbugs/bug323.go
because we already have a bugs/bug322.go and bug322.dir.

R=rsc
CC=golang-dev
https://golang.org/cl/4219044

test/bugs/bug324.dir/main.go

+// Copyright 2011 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
+
+import (
+	"./p"
+)
+
+type Exported interface {
+	private()
+}
+
+type Implementation struct{}
+
+func (p *Implementation) private() { println("main.Implementation.private()") }
+
+
+func main() {
+	// nothing unusual here
+	var x Exported
+	x = new(Implementation)
+	x.private()  //  main.Implementation.private()
+
+	// same here - should be and is legal
+	var px p.Exported
+	px = p.X
+	
+	// this assignment is correctly illegal:
+	//	px.private undefined (cannot refer to unexported field or method private)
+	// px.private()
+
+	// this assignment is correctly illegal:
+	//	*Implementation does not implement p.Exported (missing p.private method)
+	// px = new(Implementation)
+
+	// this assignment is correctly illegal:
+	//	p.Exported does not implement Exported (missing private method)
+	// x = px
+
+	// this assignment unexpectedly compiles and then executes
+	x = px.(Exported)  // ERROR "does not implement"
+
+	// this is a legitimate call, but because of the previous assignment,
+	// it invokes the method private in p!
+	x.private()  // p.Implementation.private()
+}

test/bugs/bug324.dir/p.go

+// Copyright 2011 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 p
+
+type Exported interface {
+	private()
+}
+
+type Implementation struct{}
+
+func (p *Implementation) private() { println("p.Implementation.private()") }
+
+var X = new(Implementation)

test/bugs/bug324.go

+// $G $D/$F.dir/p.go && errchk $G $D/$F.dir/main.go
+
+// Copyright 2011 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.
+
+// Test case for issue 1550
+ignored

test/golden.out

@@ -164,3 +164,6 @@ bugs/bug322.dir/main.go:19: implicit assignment of unexported field 'x' of lib.T
 bugs/bug322.dir/main.go:22: implicit assignment of unexported field 'x' of lib.T in assignment
 bugs/bug322.dir/main.go:31: implicit assignment of unexported field 'x' of lib.T in method receiver
 BUG: fails incorrectly
+
+=========== bugs/bug324.go
+BUG: errchk: command succeeded unexpectedly