add test

Author: Davies Liu

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

@@ -1032,8 +1032,8 @@ case class ScalaUDF(
     val funcArguments = converterTerms.zipWithIndex.map {
       case (converter, i) =>
         val eval = evals(i)
-        val boxedType = ctx.boxedType(children(i).dataType)
-        s"$converter.apply(${eval.isNull} ? ($boxedType) null : ($boxedType) ${eval.value})"
+        val dt = children(i).dataType
+        s"$converter.apply(${eval.isNull} ? null : (${ctx.boxedType(dt)})(${eval.value}))"
     }.mkString(",")
     val callFunc = s"${ctx.boxedType(ctx.javaType(dataType))} $resultTerm = " +
       s"(${ctx.boxedType(ctx.javaType(dataType))})${catalystConverterTerm}" +

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

@@ -1148,6 +1148,9 @@ class DataFrameSuite extends QueryTest with SharedSQLContext {
     }
     checkAnswer(df.select(boxedUDF($"age")), Row(44) :: Row(-10) :: Nil)
 
+    sqlContext.udf.register("boxedUDF", (i: java.lang.Integer) => if (i == null) -10 else i * 2)
+    checkAnswer(sql("select boxedUDF(null), boxedUDF(-1)"), Row(-10, -2) :: Nil)
+
     val primitiveUDF = udf((i: Int) => i * 2)
     checkAnswer(df.select(primitiveUDF($"age")), Row(44) :: Row(null) :: Nil)
   }