fix: filter EXTERNAL property in SparkCatalogMetaStoreClient.toCatalogTable

hudi-spark-datasource/hudi-spark-common/src/main/scala/org/apache/spark/sql/hive/SparkCatalogMetaStoreClient.scala

@@ -311,8 +311,15 @@ class SparkCatalogMetaStoreClient(syncConfig: HiveSyncConfig)
     // table property keys may not start with 'spark.sql.'") because they are reserved for
     // Spark's internal use (provider, schema parts, create version). Spark re-derives and
     // writes these from the CatalogTable itself, so dropping them on the way in is safe.
+    //
+    // Also strip "EXTERNAL". HMSDDLExecutor.createTable sets both
+    // `tableType=EXTERNAL_TABLE` and `parameters[EXTERNAL]=TRUE`. Spark's
+    // HiveExternalCatalog.verifyTableProperties rejects "EXTERNAL" as a property key
+    // ("Cannot set or change the preserved property key: 'EXTERNAL'") because it controls
+    // table type via CatalogTableType instead. The tableType field below already encodes
+    // that information, so dropping the property is safe.
     val tableProperties = Option(table.getParameters).map(_.asScala.toMap).getOrElse(Map.empty)
-      .filterNot { case (k, _) => k.startsWith("spark.sql.") }
+      .filterNot { case (k, _) => k.startsWith("spark.sql.") || k == "EXTERNAL" }
 
     CatalogTable(
       identifier = TableIdentifier(tbl, Some(db)),

hudi-spark-datasource/hudi-spark/src/test/scala/org/apache/spark/sql/hive/TestSparkCatalogMetaStoreClient.scala

@@ -177,6 +177,32 @@ class TestSparkCatalogMetaStoreClient extends FunSuite with BeforeAndAfterAll {
     }
   }
 
+  test("createTable accepts EXTERNAL=TRUE parameter (mirrors HMSDDLExecutor behavior)") {
+    withTempDir { tmp =>
+      val client = newClient()
+      val databaseName = generateName("db")
+      val tableName = generateName("tbl")
+
+      client.createDatabase(new Database(databaseName, "test database", new File(tmp, databaseName).toURI.toString, new util.HashMap[String, String]()))
+
+      // Hudi's HMSDDLExecutor.createTable sets BOTH `tableType=EXTERNAL_TABLE` and
+      // `parameters[EXTERNAL]=TRUE` on the Hive Table object. Spark's
+      // HiveExternalCatalog.verifyTableProperties rejects "EXTERNAL" as a property key
+      // unless we strip it in toCatalogTable. This test mirrors that real-world shape.
+      val createdTable = newTable(
+        databaseName,
+        tableName,
+        new File(tmp, tableName).toURI.toString,
+        Seq("id" -> "int", "name" -> "string"),
+        Seq("dt" -> "string"),
+        Map("EXTERNAL" -> "TRUE", "comment" -> "v1"))
+
+      client.createTable(createdTable)
+      assertTrue(client.tableExists(databaseName, tableName))
+      assertEquals("v1", client.getTable(databaseName, tableName).getParameters.get("comment"))
+    }
+  }
+
   private def newClient(): SparkCatalogMetaStoreClient = {
     SparkSession.setActiveSession(spark)
     SparkSession.setDefaultSession(spark)