na.fill will change the values in long or integer when the default value is in double

Author: DB Tsai

sql/core/src/main/scala/org/apache/spark/sql/DataFrameNaFunctions.scala

@@ -407,10 +407,11 @@ final class DataFrameNaFunctions private[sql](df: DataFrame) {
     val quotedColName = "`" + col.name + "`"
     val colValue = col.dataType match {
       case DoubleType | FloatType =>
-        nanvl(df.col(quotedColName), lit(null)) // nanvl only supports these types
+        // nanvl only supports these types
+        nanvl(df.col(quotedColName), lit(null).cast(col.dataType))
       case _ => df.col(quotedColName)
     }
-    coalesce(colValue, lit(replacement)).cast(col.dataType).as(col.name)
+    coalesce(colValue, lit(replacement).cast(col.dataType)).as(col.name)
   }
 
   /**

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

@@ -145,6 +145,13 @@ class DataFrameNaFunctionsSuite extends QueryTest with SharedSQLContext {
       Row(1, 2) :: Row(-1, -2) :: Row(9123146099426677101L, 9123146560113991650L) :: Nil
     )
 
+    checkAnswer(
+      Seq[(java.lang.Long, java.lang.Double)]((null, 3.14), (9123146099426677101L, null),
+        (9123146560113991650L, 1.6), (null, null)).toDF("a", "b").na.fill(0.2),
+      Row(0, 3.14) :: Row(9123146099426677101L, 0.3) :: Row(9123146560113991650L, 1.6)
+        :: Row(0, 0.2) :: Nil
+    )
+
     checkAnswer(
       Seq[(java.lang.Long, java.lang.Double)]((null, 1.23), (3L, null), (4L, 3.45))
         .toDF("a", "b").na.fill(2.34),