Merge branch 'bb-10.4-release' into 10.4

Author: vuvova

mysql-test/main/grant5.result

@@ -127,3 +127,6 @@ disconnect conn1;
 connection default;
 drop database mysqltest_1;
 drop user twg@'%';
+insert mysql.tables_priv (host,db,user,table_name,grantor,table_priv) values ('localhost','','otto','t1','root@localhost','select');
+flush privileges;
+delete from mysql.tables_priv where db='';

mysql-test/main/grant5.test

@@ -124,3 +124,10 @@ connection default;
 
 drop database mysqltest_1;
 drop user twg@'%';
+
+#
+# test the empty db case
+#
+insert mysql.tables_priv (host,db,user,table_name,grantor,table_priv) values ('localhost','','otto','t1','root@localhost','select');
+flush privileges;
+delete from mysql.tables_priv where db='';

sql/sql_acl.cc

@@ -5084,14 +5084,14 @@ GRANT_NAME::GRANT_NAME(TABLE *form, bool is_routine)
   update_hostname(&host, hostname);
 
   db=    get_field(&grant_memroot,form->field[1]);
-  sort=  get_magic_sort("hdu", host.hostname, db, user);
   tname= get_field(&grant_memroot,form->field[3]);
   if (!db || !tname)
   {
     /* Wrong table row; Ignore it */
     privs= 0;
     return;					/* purecov: inspected */
   }
+  sort=  get_magic_sort("hdu", host.hostname, db, user);
   if (lower_case_table_names)
   {
     my_casedn_str(files_charset_info, db);