[SPARK-26794][SQL]SparkSession enableHiveSupport does not point to hive but in-memory while the SparkContext exists

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

@@ -127,7 +127,7 @@ class SparkSession private(
   @Unstable
   @transient
   lazy val sharedState: SharedState = {
-    existingSharedState.getOrElse(new SharedState(sparkContext))
+    existingSharedState.getOrElse(new SharedState(sparkContext, initialSessionOptions))
   }
 
   /**

sql/core/src/main/scala/org/apache/spark/sql/internal/SharedState.scala

@@ -40,25 +40,39 @@ import org.apache.spark.util.{MutableURLClassLoader, Utils}
 /**
  * A class that holds all state shared across sessions in a given [[SQLContext]].
  */
-private[sql] class SharedState(val sparkContext: SparkContext) extends Logging {
+private[sql] class SharedState(
+    val sparkContext: SparkContext,
+    initialConfigs: scala.collection.Map[String, String])
+  extends Logging {
+  private val conf = sparkContext.conf.clone()
+  private val hadoopConf = new Configuration(sparkContext.hadoopConfiguration)
+
+  // If `SparkSession` is instantiated using an existing `SparkContext` instance and no existing
+  // `SharedState`, all `SparkSession` level configurations have higher priority to generate a
+  // `SharedState` instance. This will be done only once then shared across `SparkSession`s
+  initialConfigs.foreach { case (k, v) =>
+    logDebug(s"Applying initial SparkSession options to SparkConf/HadoopConf: $k -> $v")
+    conf.set(k, v)
+    hadoopConf.set(k, v)
+  }
 
   // Load hive-site.xml into hadoopConf and determine the warehouse path we want to use, based on
   // the config from both hive and Spark SQL. Finally set the warehouse config value to sparkConf.
   val warehousePath: String = {
     val configFile = Utils.getContextOrSparkClassLoader.getResource("hive-site.xml")
     if (configFile != null) {
       logInfo(s"loading hive config file: $configFile")
-      sparkContext.hadoopConfiguration.addResource(configFile)
+      hadoopConf.addResource(configFile)
     }
 
     // hive.metastore.warehouse.dir only stay in hadoopConf
-    sparkContext.conf.remove("hive.metastore.warehouse.dir")
+    conf.remove("hive.metastore.warehouse.dir")
     // Set the Hive metastore warehouse path to the one we use
-    val hiveWarehouseDir = sparkContext.hadoopConfiguration.get("hive.metastore.warehouse.dir")
-    if (hiveWarehouseDir != null && !sparkContext.conf.contains(WAREHOUSE_PATH.key)) {
+    val hiveWarehouseDir = hadoopConf.get("hive.metastore.warehouse.dir")
+    if (hiveWarehouseDir != null && !conf.contains(WAREHOUSE_PATH.key)) {
       // If hive.metastore.warehouse.dir is set and spark.sql.warehouse.dir is not set,
       // we will respect the value of hive.metastore.warehouse.dir.
-      sparkContext.conf.set(WAREHOUSE_PATH.key, hiveWarehouseDir)
+      conf.set(WAREHOUSE_PATH.key, hiveWarehouseDir)
       logInfo(s"${WAREHOUSE_PATH.key} is not set, but hive.metastore.warehouse.dir " +
         s"is set. Setting ${WAREHOUSE_PATH.key} to the value of " +
         s"hive.metastore.warehouse.dir ('$hiveWarehouseDir').")
@@ -68,13 +82,14 @@ private[sql] class SharedState(val sparkContext: SparkContext) extends Logging {
       // the value of spark.sql.warehouse.dir.
       // When neither spark.sql.warehouse.dir nor hive.metastore.warehouse.dir is set,
       // we will set hive.metastore.warehouse.dir to the default value of spark.sql.warehouse.dir.
-      val sparkWarehouseDir = sparkContext.conf.get(WAREHOUSE_PATH)
+      val sparkWarehouseDir = conf.get(WAREHOUSE_PATH)
       logInfo(s"Setting hive.metastore.warehouse.dir ('$hiveWarehouseDir') to the value of " +
         s"${WAREHOUSE_PATH.key} ('$sparkWarehouseDir').")
-      sparkContext.hadoopConfiguration.set("hive.metastore.warehouse.dir", sparkWarehouseDir)
+      hadoopConf.set("hive.metastore.warehouse.dir", sparkWarehouseDir)
       sparkWarehouseDir
     }
   }
+  sparkContext.conf.set(WAREHOUSE_PATH.key, warehousePath)
   logInfo(s"Warehouse path is '$warehousePath'.")
 
 
@@ -101,9 +116,7 @@ private[sql] class SharedState(val sparkContext: SparkContext) extends Logging {
    */
   lazy val externalCatalog: ExternalCatalogWithListener = {
     val externalCatalog = SharedState.reflect[ExternalCatalog, SparkConf, Configuration](
-      SharedState.externalCatalogClassName(sparkContext.conf),
-      sparkContext.conf,
-      sparkContext.hadoopConfiguration)
+      SharedState.externalCatalogClassName(conf), conf, hadoopConf)
 
     val defaultDbDefinition = CatalogDatabase(
       SessionCatalog.DEFAULT_DATABASE,
@@ -137,7 +150,7 @@ private[sql] class SharedState(val sparkContext: SparkContext) extends Logging {
     // System preserved database should not exists in metastore. However it's hard to guarantee it
     // for every session, because case-sensitivity differs. Here we always lowercase it to make our
     // life easier.
-    val globalTempDB = sparkContext.conf.get(GLOBAL_TEMP_DATABASE).toLowerCase(Locale.ROOT)
+    val globalTempDB = conf.get(GLOBAL_TEMP_DATABASE).toLowerCase(Locale.ROOT)
     if (externalCatalog.databaseExists(globalTempDB)) {
       throw new SparkException(
         s"$globalTempDB is a system preserved database, please rename your existing database " +

sql/hive/src/main/scala/org/apache/spark/sql/hive/test/TestHive.scala

@@ -90,7 +90,7 @@ private[hive] class TestHiveExternalCatalog(
 private[hive] class TestHiveSharedState(
     sc: SparkContext,
     hiveClient: Option[HiveClient] = None)
-  extends SharedState(sc) {
+  extends SharedState(sc, Map.empty) {
 
   override lazy val externalCatalog: ExternalCatalogWithListener = {
     new ExternalCatalogWithListener(new TestHiveExternalCatalog(

sql/hive/src/test/scala/org/apache/spark/sql/internal/SharedStateSuite.scala

@@ -0,0 +1,37 @@
+/*
+ * 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.internal
+
+import org.apache.spark.{SparkConf, SparkContext, SparkFunSuite}
+import org.apache.spark.sql.SparkSession
+
+class SharedStateSuite extends SparkFunSuite {
+
+  test("the catalog should be determined at the very first") {
+    val conf = new SparkConf().setMaster("local").setAppName("SharedState Test")
+    val sc = SparkContext.getOrCreate(conf)
+    val ss = SparkSession.builder().enableHiveSupport().getOrCreate()
+    assert(ss.sharedState.externalCatalog.unwrapped.getClass.getName ===
+      "org.apache.spark.sql.hive.HiveExternalCatalog", "The catalog should be hive ")
+
+    val ss2 = SparkSession.builder().getOrCreate()
+    assert(ss2.sharedState.externalCatalog.unwrapped.getClass.getName ===
+      "org.apache.spark.sql.hive.HiveExternalCatalog",
+      "The catalog should be shared across sessions")
+  }
+}