Review.

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

@@ -1004,7 +1004,7 @@ object SparkSession {
 
   /**
    * Helper method to create an instance of `SessionState` based on `className` from conf.
-   * The result is either `SessionState` or `HiveSessionState`
+   * The result is either `SessionState` or `HiveSessionState`.
    */
   private def instantiateSessionState(
       className: String,

sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala

@@ -274,6 +274,7 @@ private[hive] class HiveClientImpl(
     val original = Thread.currentThread().getContextClassLoader
     // Set the thread local metastore client to the client associated with this HiveClientImpl.
     Hive.set(client)
+    // replace conf in cached hive with current conf
     Hive.get(conf)
     // The classloader in clientLoader could be changed after addJar, always use the latest
     // classloader

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

@@ -49,6 +49,7 @@ class HiveSessionCatalogSuite extends SessionCatalogSuite {
       new Configuration(),
       new SimpleFunctionRegistry,
       CatalystSqlParser)
+    assert(original ne clone)
     assert(clone.getTempView("copytest1") == Option(tempTable1))
 
     // check if clone and original independent

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

@@ -22,11 +22,8 @@ import org.scalatest.BeforeAndAfterEach
 import org.apache.spark.sql._
 import org.apache.spark.sql.hive.test.TestHiveSingleton
 
-class HiveSessionStateSuite
-  extends SessionStateSuite
-  with TestHiveSingleton
-  with BeforeAndAfterEach {
-
+class HiveSessionStateSuite extends SessionStateSuite
+  with TestHiveSingleton with BeforeAndAfterEach {
 
   override def beforeEach(): Unit = {
     createSession()