support udt->hive types (hive->udt is not supported)

Author: mengxr

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveMetastoreCatalog.scala

@@ -390,6 +390,7 @@ object HiveMetastoreTypes extends RegexParsers {
     case d: DecimalType => HiveShim.decimalMetastoreString(d)
     case TimestampType => "timestamp"
     case NullType => "void"
+    case udt: UserDefinedType[_] => toMetastoreType(udt.sqlType)
   }
 }
 

sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveMetastoreCatalogSuite.scala

@@ -19,7 +19,8 @@ package org.apache.spark.sql.hive
 
 import org.scalatest.FunSuite
 
-import org.apache.spark.sql.catalyst.types.{DataType, StructType}
+import org.apache.spark.sql.catalyst.types.StructType
+import org.apache.spark.sql.test.ExamplePointUDT
 
 class HiveMetastoreCatalogSuite extends FunSuite {
 
@@ -29,4 +30,10 @@ class HiveMetastoreCatalogSuite extends FunSuite {
     val datatype = HiveMetastoreTypes.toDataType(metastr)
     assert(datatype.isInstanceOf[StructType])
   }
+
+  test("udt to metastore type conversion") {
+    val udt = new ExamplePointUDT
+    assert(HiveMetastoreTypes.toMetastoreType(udt) ===
+      HiveMetastoreTypes.toMetastoreType(udt.sqlType))
+  }
 }