HIVE-29865: Fix metastore database filter context returning null DB names

ql/src/java/org/apache/hadoop/hive/ql/security/authorization/plugin/metastore/filtercontext/DatabaseFilterContext.java

@@ -89,7 +89,7 @@ private List<HivePrivilegeObject> getInputHObjs() {
       if (db != null) {
         ret.add(getHivePrivilegeObject(db));
       } else {
-        HivePrivilegeObject hivePrivilegeObject = new HivePrivilegeObject(type, dbName);
+        HivePrivilegeObject hivePrivilegeObject = new HivePrivilegeObject(type, catName, dbName, dbName);
         ret.add(hivePrivilegeObject);
       }
     }

ql/src/test/org/apache/hadoop/hive/ql/security/authorization/plugin/metastore/TestHiveMetaStoreAuthorizerFilterDatabases.java

@@ -0,0 +1,74 @@
+/*
+ * 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.hadoop.hive.ql.security.authorization.plugin.metastore;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hive.metastore.HiveMetaStoreClient;
+import org.apache.hadoop.hive.metastore.MetaStoreTestUtils;
+import org.apache.hadoop.hive.metastore.conf.MetastoreConf;
+import org.apache.hadoop.hive.metastore.conf.MetastoreConf.ConfVars;
+import org.apache.hadoop.hive.ql.security.authorization.plugin.fallback.FallbackHiveAuthorizerFactory;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+public class TestHiveMetaStoreAuthorizerFilterDatabases {
+
+  private Configuration conf;
+  private int metastorePort = -1;
+  private HiveMetaStoreClient client;
+
+  @Before
+  public void setUp() throws Exception {
+    conf = MetastoreConf.newMetastoreConf();
+    MetastoreConf.setVar(conf, ConfVars.HIVE_AUTHORIZATION_MANAGER, FallbackHiveAuthorizerFactory.class.getName());
+    MetastoreConf.setVar(conf, ConfVars.FILTER_HOOK, HiveMetaStoreAuthorizer.class.getName());
+    MetastoreConf.setBoolVar(conf, ConfVars.METASTORE_CLIENT_FILTER_ENABLED, true);
+    MetaStoreTestUtils.setConfForStandloneMode(conf);
+    metastorePort = MetaStoreTestUtils.startMetaStoreWithRetry(conf);
+    client = new HiveMetaStoreClient(conf);
+  }
+
+  @After
+  public void tearDown() {
+    if (client != null) {
+      client.close();
+    }
+    if (metastorePort > 0) {
+      MetaStoreTestUtils.close(metastorePort);
+    }
+  }
+
+  @Test
+  public void testGetAllDatabasesReturnsNamesWithFilterHook() throws Exception {
+    List<String> databases = client.getAllDatabases();
+    assertFalse("getAllDatabases returned empty list", databases.isEmpty());
+    for (String dbName : databases) {
+      assertNotNull("getAllDatabases returned null DB name", dbName);
+    }
+    assertTrue("default database not present in DB list", databases.contains("default"));
+  }
+}