new bug

R=r
DELTA=34  (34 added, 0 deleted, 0 changed)
OCL=15178
CL=15181

test/bugs/bug099.go

@@ -0,0 +1,38 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG should not crash
+
+// 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.
+
+package main
+
+// Interface
+type I interface { F() int }
+
+// Implements interface
+type S struct { }
+func (s *S) F() int { return 1 }
+
+// Allocates S but returns I
+// Arg is unused but important:
+// if you take it out (and the 0s below)
+// then the bug goes away.
+func NewI(i int) I {
+	return new(S)
+}
+
+// Uses interface method.
+func Use(x I) {
+	x.F()
+}
+
+func main() {
+	i := NewI(0);
+	Use(i);
+	print("done1\n");
+	
+	// Again, without temporary
+	// Crashes because x.F is 0.
+	Use(NewI(0));
+}
+