[SPARK-5504] [sql] convertToCatalyst should support nested arrays

After the recent refactoring, convertToCatalyst in ScalaReflection does not recurse on Arrays. It should.

The test suite modification made the test fail before the fix in ScalaReflection.  The fix makes the test suite succeed.

CC: marmbrus

Author: Joseph K. Bradley <joseph@databricks.com>

Closes #4295 from jkbradley/SPARK-5504 and squashes the following commits:

6b7276d [Joseph K. Bradley] Fixed issue in ScalaReflection.convertToCatalyst with Arrays with non-primitive types. Modified test suite so it failed before the fix and works after the fix.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/ScalaReflection.scala

@@ -57,7 +57,11 @@ trait ScalaReflection {
     case (obj, udt: UserDefinedType[_]) => udt.serialize(obj)
     case (o: Option[_], _) => o.map(convertToCatalyst(_, dataType)).orNull
     case (s: Seq[_], arrayType: ArrayType) => s.map(convertToCatalyst(_, arrayType.elementType))
-    case (s: Array[_], arrayType: ArrayType) => s.toSeq
+    case (s: Array[_], arrayType: ArrayType) => if (arrayType.elementType.isPrimitive) {
+      s.toSeq
+    } else {
+      s.toSeq.map(convertToCatalyst(_, arrayType.elementType))
+    }
     case (m: Map[_, _], mapType: MapType) => m.map { case (k, v) =>
       convertToCatalyst(k, mapType.keyType) -> convertToCatalyst(v, mapType.valueType)
     }

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/ScalaReflectionSuite.scala

@@ -64,7 +64,8 @@ case class ComplexData(
     arrayFieldContainsNull: Seq[java.lang.Integer],
     mapField: Map[Int, Long],
     mapFieldValueContainsNull: Map[Int, java.lang.Long],
-    structField: PrimitiveData)
+    structField: PrimitiveData,
+    nestedArrayField: Array[Array[Int]])
 
 case class GenericData[A](
     genericField: A)
@@ -158,7 +159,10 @@ class ScalaReflectionSuite extends FunSuite {
             StructField("shortField", ShortType, nullable = false),
             StructField("byteField", ByteType, nullable = false),
             StructField("booleanField", BooleanType, nullable = false))),
-          nullable = true))),
+          nullable = true),
+        StructField(
+          "nestedArrayField",
+          ArrayType(ArrayType(IntegerType, containsNull = false), containsNull = true)))),
       nullable = true))
   }