[SPARK-5840][SQL] HiveContext cannot be serialized due to tuple extraction

Also added test cases for checking the serializability of HiveContext and SQLContext.

Author: Reynold Xin <rxin@databricks.com>

Closes #4628 from rxin/SPARK-5840 and squashes the following commits:

ecb3bcd [Reynold Xin] test cases and reviews.
55eb822 [Reynold Xin] [SPARK-5840][SQL] HiveContext cannot be serialized due to tuple extraction.

1 files changed, 32 insertions, 0 deletions

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SerializationSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SerializationSuite.scala
new file mode 100644
index 0000000000..6f6d3c9c24
--- /dev/null
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SerializationSuite.scala
@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql
+
+import org.scalatest.FunSuite
+
+import org.apache.spark.SparkConf
+import org.apache.spark.serializer.JavaSerializer
+import org.apache.spark.sql.test.TestSQLContext
+
+class SerializationSuite extends FunSuite {
+
+  test("[SPARK-5235] SQLContext should be serializable") {
+    val sqlContext = new SQLContext(TestSQLContext.sparkContext)
+    new JavaSerializer(new SparkConf()).newInstance().serialize(sqlContext)
+  }
+}