auto merge of #8439 : huonw/rust/hashset-clone, r=cmr

Closes #5581.

diff --cc src/libstd/hashmap.rs
index 7a22477685911cf9ee0a52afdc9f882b1ce3f49d,623d395f60d676e25f17febdab9748d2135df00f..201d4692694650158124b87df403d610b5579591
--- 1/src/libstd/hashmap.rs
--- 2/src/libstd/hashmap.rs
+++ b/src/libstd/hashmap.rs
@@@ -1187,7 -1195,25 +1195,25 @@@ mod test_set 
              hs
          };
  
 -        let v = hs.consume().collect::<~[char]>();
 +        let v = hs.move_iter().collect::<~[char]>();
          assert!(['a', 'b'] == v || ['b', 'a'] == v);
      }
+ 
+     #[test]
+     fn test_eq() {
+         let mut s1 = HashSet::new();
+         s1.insert(1);
+         s1.insert(2);
+         s1.insert(3);
+ 
+         let mut s2 = HashSet::new();
+         s2.insert(1);
+         s2.insert(2);
+ 
+         assert!(s1 != s2);
+ 
+         s2.insert(3);
+ 
+         assert_eq!(s1, s2);
+     }
  }