fix bug in test

Author: chenghao-intel

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

@@ -78,8 +78,7 @@ abstract class BinaryArithmetic extends BinaryExpression {
 
   override lazy val resolved =
     left.resolved && right.resolved &&
-    left.dataType == right.dataType &&
-    !DecimalType.isFixed(left.dataType)
+    left.dataType == right.dataType
 
   def dataType: DataType = {
     if (!resolved) {

sql/core/src/main/scala/org/apache/spark/sql/execution/Aggregate.scala

@@ -407,7 +407,7 @@ case class DistinctAggregate(
             val value = ae.eval(currentRow)
 
             if (ae.distinct) {
-              if (!seens(idx).contains(value)) {
+              if (value != null && !seens(idx).contains(value)) {
                 ae.iterate(value, buffer)
                 seens(idx).add(value)
               }
@@ -434,7 +434,7 @@ case class DistinctAggregate(
                 val value = ae.eval(currentRow)
 
                 if (ae.distinct) {
-                  if (!inputBufferSeens.seens(idx).contains(value)) {
+                  if (value != null && !inputBufferSeens.seens(idx).contains(value)) {
                     ae.iterate(value, inputBufferSeens.buffer)
                     inputBufferSeens.seens(idx).add(value)
                   }