[SPARK-19905][SQL] Bring back Dataset.inputFiles for Hive SerDe tables

## What changes were proposed in this pull request?

`Dataset.inputFiles` works by matching `FileRelation`s in the query plan. In Spark 2.1, Hive SerDe tables are represented by `MetastoreRelation`, which inherits from `FileRelation`. However, in Spark 2.2, Hive SerDe tables are now represented by `CatalogRelation`, which doesn't inherit from `FileRelation` anymore, due to the unification of Hive SerDe tables and data source tables. This change breaks `Dataset.inputFiles` for Hive SerDe tables.

This PR tries to fix this issue by explicitly matching `CatalogRelation`s that are Hive SerDe tables in `Dataset.inputFiles`. Note that we can't make `CatalogRelation` inherit from `FileRelation` since not all `CatalogRelation`s are file based (e.g., JDBC data source tables).

## How was this patch tested?

New test case added in `HiveDDLSuite`.

Author: Cheng Lian <[email protected]>

Closes #17247 from liancheng/spark-19905-hive-table-input-files.

Author: liancheng

sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala

@@ -36,6 +36,7 @@ import org.apache.spark.broadcast.Broadcast
 import org.apache.spark.rdd.RDD
 import org.apache.spark.sql.catalyst._
 import org.apache.spark.sql.catalyst.analysis._
+import org.apache.spark.sql.catalyst.catalog.CatalogRelation
 import org.apache.spark.sql.catalyst.encoders._
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.expressions.aggregate._
@@ -2734,6 +2735,8 @@ class Dataset[T] private[sql](
         fsBasedRelation.inputFiles
       case fr: FileRelation =>
         fr.inputFiles
+      case r: CatalogRelation if DDLUtils.isHiveTable(r.tableMeta) =>
+        r.tableMeta.storage.locationUri.map(_.toString).toArray
     }.flatten
     files.toSet.toArray
   }

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala

@@ -1865,4 +1865,15 @@ class HiveDDLSuite
       }
     }
   }
+
+  test("SPARK-19905: Hive SerDe table input paths") {
+    withTable("spark_19905") {
+      withTempView("spark_19905_view") {
+        spark.range(10).createOrReplaceTempView("spark_19905_view")
+        sql("CREATE TABLE spark_19905 STORED AS RCFILE AS SELECT * FROM spark_19905_view")
+        assert(spark.table("spark_19905").inputFiles.nonEmpty)
+        assert(sql("SELECT input_file_name() FROM spark_19905").count() > 0)
+      }
+    }
+  }
 }