[CACRBONDATA-317] CSV having only space char is throwing NullPointer.…

… This closes apache#237

integration/spark/src/main/scala/org/apache/carbondata/spark/csv/CarbonCsvRelation.scala

@@ -33,6 +33,8 @@ import org.apache.spark.sql.sources.{BaseRelation, InsertableRelation, TableScan
 import org.apache.spark.sql.types._
 import org.slf4j.LoggerFactory
 
+import org.apache.carbondata.processing.etl.DataLoadingException
+
 case class CarbonCsvRelation protected[spark] (
     location: String,
     useHeader: Boolean,
@@ -148,6 +150,9 @@ case class CarbonCsvRelation protected[spark] (
           .withSkipHeaderRecord(false)
         CSVParser.parse(firstLine, csvFormat).getRecords.get(0).asScala.toArray
       }
+      if(null == firstRow) {
+        throw new DataLoadingException("First line of the csv is not valid.")
+      }
       val header = if (useHeader) {
         firstRow
       } else {

integration/spark/src/test/resources/emptyrow/csvwithonlyspacechar.csv

@@ -0,0 +1 @@
+

integration/spark/src/test/scala/org/apache/carbondata/integration/spark/testsuite/emptyrow/TestCSVHavingOnlySpaceChar.scala

@@ -0,0 +1,68 @@
+/*
+ * 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.carbondata.integration.spark.testsuite.emptyrow
+
+import java.io.File
+
+import org.apache.spark.sql.common.util.CarbonHiveContext._
+import org.apache.spark.sql.common.util.QueryTest
+import org.scalatest.BeforeAndAfterAll
+
+import org.apache.carbondata.core.constants.CarbonCommonConstants
+import org.apache.carbondata.core.util.CarbonProperties
+
+class TestCSVHavingOnlySpaceChar extends QueryTest with BeforeAndAfterAll {
+
+  var csvFilePath : String = null
+
+  override def beforeAll {
+    sql("drop table if exists emptyRowCarbonTable")
+    //eid,ename,sal,presal,comm,deptno,Desc
+    sql(
+      "create table if not exists emptyRowCarbonTable (eid int,ename String,sal decimal,presal " +
+        "decimal,comm decimal" +
+        "(37,37),deptno decimal(18,2),Desc String) STORED BY 'org.apache.carbondata.format'"
+    )
+    CarbonProperties.getInstance()
+      .addProperty(CarbonCommonConstants.CARBON_TIMESTAMP_FORMAT, "yyyy/mm/dd")
+    val currentDirectory = new File(this.getClass.getResource("/").getPath + "/../../")
+      .getCanonicalPath
+     csvFilePath = currentDirectory + "/src/test/resources/emptyrow/csvwithonlyspacechar.csv"
+      }
+
+
+  test("dataload") {
+    try {
+      sql(
+        s"""LOAD DATA INPATH '$csvFilePath' INTO table emptyRowCarbonTable OPTIONS('DELIMITER'=',','QUOTECHAR'='"')""")
+    } catch {
+      case e: Throwable =>
+        System.out.println(e.getMessage)
+        assert(e.getMessage.contains("First line of the csv is not valid."))
+    }
+  }
+
+  override def afterAll {
+    sql("drop table emptyRowCarbonTable")
+    sql("drop table emptyRowHiveTable")
+    CarbonProperties.getInstance()
+      .addProperty(CarbonCommonConstants.CARBON_TIMESTAMP_FORMAT, "dd-MM-yyyy")
+  }
+}