auto merge of #12641 : sfackler/rust/issue-11552, r=huonw

Closes #11552

Author: bors

src/test/run-pass/issue-11552.rs

@@ -0,0 +1,29 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[deriving(Clone)]
+enum Noun
+{
+    Atom(int),
+    Cell(~Noun, ~Noun)
+}
+
+fn fas(n: &Noun) -> Noun
+{
+    match n
+    {
+        &Cell(~Atom(2), ~Cell(ref a, _)) => (**a).clone(),
+        _ => fail!("Invalid fas pattern")
+    }
+}
+
+pub fn main() {
+    fas(&Cell(~Atom(2), ~Cell(~Atom(2), ~Atom(3))));
+}