Address the comments

Author: jerryshao

sql/core/src/test/scala/org/apache/spark/sql/DatasetSuite.scala

@@ -769,14 +769,14 @@ class DatasetSuite extends QueryTest with SharedSQLContext {
     }
   }
 
-  test("transformed dataset correctly solve the attributes") {
-    val dataset = Seq(1, 2, 3).toDS()
-    val ds1 = dataset.map(_ + 1)
-
-    checkDataset(ds1.as("d1").joinWith(ds1.as("d2"), $"d1.value" === $"d2.value"),
-      (2, 2), (3, 3), (4, 4))
-    checkDataset(ds1.as("d1").intersect(ds1.as("d2")), 2, 3, 4)
-    checkDataset(ds1.as("d1").except(ds1.as("d2")))
+  test("mapped dataset should resolve duplicated attributes for self join") {
+    val ds = Seq(1, 2, 3).toDS().map(_ + 1)
+    val ds1 = ds.as("d1")
+    val ds2 = ds.as("d2")
+
+    checkDataset(ds1.joinWith(ds2, $"d1.value" === $"d2.value"), (2, 2), (3, 3), (4, 4))
+    checkDataset(ds1.intersect(ds2), 2, 3, 4)
+    checkDataset(ds1.except(ds1))
   }
 
   test("SPARK-15441: Dataset outer join") {