fix bug in Nanvl type coercion

Author: yjshen

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala

@@ -563,11 +563,10 @@ object HiveTypeCoercion {
           case None => c
         }
 
-      case n @ NaNvl(l, r) if l.dataType != r.dataType =>
-        l.dataType match {
-          case DoubleType => NaNvl(l, Cast(r, DoubleType))
-          case FloatType => NaNvl(Cast(l, DoubleType), r)
-        }
+      case NaNvl(l, r) if l.dataType == DoubleType && r.dataType == FloatType =>
+        NaNvl(l, Cast(r, DoubleType))
+      case NaNvl(l, r) if l.dataType == FloatType && r.dataType == DoubleType =>
+        NaNvl(Cast(l, DoubleType), r)
     }
   }
 

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

@@ -227,20 +227,24 @@ class ColumnExpressionSuite extends QueryTest with SQLTestUtils {
 
   test("nanvl") {
     val testData = ctx.createDataFrame(ctx.sparkContext.parallelize(
-      Row(null, 3.0, Double.NaN, Double.PositiveInfinity) :: Nil),
+      Row(null, 3.0, Double.NaN, Double.PositiveInfinity, 1.0f, 4) :: Nil),
       StructType(Seq(StructField("a", DoubleType), StructField("b", DoubleType),
-        StructField("c", DoubleType), StructField("d", DoubleType))))
+        StructField("c", DoubleType), StructField("d", DoubleType),
+        StructField("e", FloatType), StructField("f", IntegerType))))
 
     checkAnswer(
       testData.select(
-        nanvl($"a", lit(5)), nanvl($"b", lit(10)),
-        nanvl($"c", lit(null).cast(DoubleType)), nanvl($"d", lit(10))),
-      Row(null, 3.0, null, Double.PositiveInfinity)
+        nanvl($"a", lit(5)), nanvl($"b", lit(10)), nanvl(lit(10), $"b"),
+        nanvl($"c", lit(null).cast(DoubleType)), nanvl($"d", lit(10)),
+        nanvl($"b", $"e"), nanvl($"e", $"f")),
+      Row(null, 3.0, 10.0, null, Double.PositiveInfinity, 3.0, 1.0)
     )
     testData.registerTempTable("t")
     checkAnswer(
-      ctx.sql("select nanvl(a, 5), nanvl(b, 10), nanvl(c, null), nanvl(d, 10) from t"),
-      Row(null, 3.0, null, Double.PositiveInfinity)
+      ctx.sql(
+        "select nanvl(a, 5), nanvl(b, 10), nanvl(10, b), nanvl(c, null), nanvl(d, 10), " +
+          " nanvl(b, e), nanvl(e, f) from t"),
+      Row(null, 3.0, 10.0, null, Double.PositiveInfinity, 3.0, 1.0)
     )
   }