auto merge of #12330 : nick29581/rust/glue, r=huonw

closes #3290

src/test/run-pass/self-re-assign.rs

@@ -0,0 +1,24 @@
+// Copyright 2012-2014 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.
+
+// Ensure assigning an owned or managed variable to itself works. In particular,
+// that we do not glue_drop before we glue_take (#3290).
+
+use std::rc::Rc;
+
+pub fn main() {
+   let mut x = ~3;
+   x = x;
+   assert!(*x == 3);
+
+   let mut x = Rc::new(3);
+   x = x;
+   assert!(*x.borrow() == 3);
+}