fix

Author: gatorsmile

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/windowExpressions.scala

@@ -45,17 +45,6 @@ case class WindowSpecDefinition(
 
   override def children: Seq[Expression] = partitionSpec ++ orderSpec :+ frameSpecification
 
-  /*
-   * The result of an OffsetWindowFunction is dependent on the frame in which the
-   * OffsetWindowFunction is executed, the input expression and the default expression. Even when
-   * both the input and the default expression are foldable, the result is still not foldable due to
-   * the frame.
-   *
-   * Note, the value of foldable is set to false in the trait Unevaluable
-   *
-   * override def foldable: Boolean = false
-   */
-
   override lazy val resolved: Boolean =
     childrenResolved && checkInputDataTypes().isSuccess &&
       frameSpecification.isInstanceOf[SpecifiedWindowFrame]
@@ -371,6 +360,17 @@ abstract class OffsetWindowFunction
 
   override def children: Seq[Expression] = Seq(input, offset, default)
 
+  /*
+   * The result of an OffsetWindowFunction is dependent on the frame in which the
+   * OffsetWindowFunction is executed, the input expression and the default expression. Even when
+   * both the input and the default expression are foldable, the result is still not foldable due to
+   * the frame.
+   *
+   * Note, the value of foldable is set to false in the trait Unevaluable
+   *
+   * override def foldable: Boolean = false
+   */
+
   override def nullable: Boolean = default == null || default.nullable || input.nullable
 
   override lazy val frame: WindowFrame = {