diff --git a/mysql-test/r/renamedb.result b/mysql-test/r/renamedb.result
index ff8f89592fc..e77aca0d0b7 100644
--- a/mysql-test/r/renamedb.result
+++ b/mysql-test/r/renamedb.result
@@ -7,6 +7,6 @@ ERROR HY000: Incorrect usage of ALTER DATABASE UPGRADE DATA DIRECTORY NAME and n
 ALTER DATABASE `#mysql51#not-yet` UPGRADE DATA DIRECTORY NAME;
 ERROR HY000: Incorrect usage of ALTER DATABASE UPGRADE DATA DIRECTORY NAME and name
 ALTER DATABASE `#mysql50#` UPGRADE DATA DIRECTORY NAME;
-ERROR HY000: Incorrect usage of ALTER DATABASE UPGRADE DATA DIRECTORY NAME and name
+ERROR 42000: Incorrect database name '#mysql50#'
 ALTER DATABASE `#mysql50#upgrade-me` UPGRADE DATA DIRECTORY NAME;
 ERROR 42000: Unknown database '#mysql50#upgrade-me'
diff --git a/mysql-test/r/upgrade.result b/mysql-test/r/upgrade.result
index 034242079b1..da2f55b5bb1 100644
--- a/mysql-test/r/upgrade.result
+++ b/mysql-test/r/upgrade.result
@@ -112,3 +112,31 @@ select * from `a-b-c`.v1;
 f1
 drop database `a-b-c`;
 use test;
+# End of 5.0 tests
+#
+# Bug #53804: serious flaws in the alter database .. upgrade data
+#             directory name command
+#
+ALTER DATABASE `#mysql50#:` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Unknown database '#mysql50#:'
+ALTER DATABASE `#mysql50#.` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#.'
+ALTER DATABASE `#mysql50#../` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#../'
+ALTER DATABASE `#mysql50#../..` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#../..'
+ALTER DATABASE `#mysql50#../../` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#../../'
+ALTER DATABASE `#mysql50#./blablabla` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#./blablabla'
+ALTER DATABASE `#mysql50#../blablabla` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#../blablabla'
+ALTER DATABASE `#mysql50#/` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#/'
+ALTER DATABASE `#mysql50#/.` UPGRADE DATA DIRECTORY NAME;
+ERROR 42000: Incorrect database name '#mysql50#/.'
+USE `#mysql50#.`;
+ERROR 42000: Incorrect database name '#mysql50#.'
+USE `#mysql50#../blablabla`;
+ERROR 42000: Incorrect database name '#mysql50#../blablabla'
+# End of 5.1 tests
diff --git a/mysql-test/t/renamedb.test b/mysql-test/t/renamedb.test
index 84315090b7a..71d0c127058 100644
--- a/mysql-test/t/renamedb.test
+++ b/mysql-test/t/renamedb.test
@@ -44,7 +44,7 @@ ALTER DATABASE `#mysql41#not-supported` UPGRADE DATA DIRECTORY NAME;
 --error ER_WRONG_USAGE
 ALTER DATABASE `#mysql51#not-yet` UPGRADE DATA DIRECTORY NAME;
 
---error ER_WRONG_USAGE
+--error ER_WRONG_DB_NAME
 ALTER DATABASE `#mysql50#` UPGRADE DATA DIRECTORY NAME;
 
 --error ER_BAD_DB_ERROR
diff --git a/mysql-test/t/upgrade.test b/mysql-test/t/upgrade.test
index e390e8a1253..a7b9a1531ff 100644
--- a/mysql-test/t/upgrade.test
+++ b/mysql-test/t/upgrade.test
@@ -137,3 +137,37 @@ select * from `a-b-c`.v1;
 --enable_ps_protocol
 drop database `a-b-c`;
 use test;
+
+--echo # End of 5.0 tests
+
+--echo #
+--echo # Bug #53804: serious flaws in the alter database .. upgrade data
+--echo #             directory name command
+--echo #
+
+--error ER_BAD_DB_ERROR
+ALTER DATABASE `#mysql50#:` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#.` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#../` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#../..` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#../../` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#./blablabla` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#../blablabla` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#/` UPGRADE DATA DIRECTORY NAME;
+--error ER_WRONG_DB_NAME
+ALTER DATABASE `#mysql50#/.` UPGRADE DATA DIRECTORY NAME;
+
+--error ER_WRONG_DB_NAME
+USE `#mysql50#.`;
+--error ER_WRONG_DB_NAME
+USE `#mysql50#../blablabla`;
+
+--echo # End of 5.1 tests
+
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 57875089cd8..f61565fe6e7 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -2293,6 +2293,7 @@ uint explain_filename(THD* thd, const char *from, char *to, uint to_length,
 uint filename_to_tablename(const char *from, char *to, uint to_length);
 uint tablename_to_filename(const char *from, char *to, uint to_length);
 uint check_n_cut_mysql50_prefix(const char *from, char *to, uint to_length);
+bool check_mysql50_prefix(const char *name);
 #endif /* MYSQL_SERVER || INNODB_COMPATIBILITY_HOOKS */
 #ifdef MYSQL_SERVER
 uint build_table_filename(char *buff, size_t bufflen, const char *db,
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 873ac4e1659..05f9fa4e398 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -391,6 +391,25 @@ uint filename_to_tablename(const char *from, char *to, uint to_length)
 }
 
 
+/**
+  Check if given string begins with "#mysql50#" prefix
+  
+  @param   name          string to check cut 
+  
+  @retval
+    FALSE  no prefix found
+  @retval
+    TRUE   prefix found
+*/
+
+bool check_mysql50_prefix(const char *name)
+{
+  return (name[0] == '#' && 
+         !strncmp(name, MYSQL50_TABLE_NAME_PREFIX,
+                  MYSQL50_TABLE_NAME_PREFIX_LENGTH));
+}
+
+
 /**
   Check if given string begins with "#mysql50#" prefix, cut it if so.
   
@@ -406,9 +425,7 @@ uint filename_to_tablename(const char *from, char *to, uint to_length)
 
 uint check_n_cut_mysql50_prefix(const char *from, char *to, uint to_length)
 {
-  if (from[0] == '#' && 
-      !strncmp(from, MYSQL50_TABLE_NAME_PREFIX,
-               MYSQL50_TABLE_NAME_PREFIX_LENGTH))
+  if (check_mysql50_prefix(from))
     return (uint) (strmake(to, from + MYSQL50_TABLE_NAME_PREFIX_LENGTH,
                            to_length - 1) - to);
   return 0;
diff --git a/sql/table.cc b/sql/table.cc
index bd6251b5743..8b97dd36170 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -2689,44 +2689,30 @@ bool check_db_name(LEX_STRING *org_name)
 {
   char *name= org_name->str;
   uint name_length= org_name->length;
+  bool check_for_path_chars;
 
   if (!name_length || name_length > NAME_LEN)
     return 1;
 
+  if ((check_for_path_chars= check_mysql50_prefix(name)))
+  {
+    name+= MYSQL50_TABLE_NAME_PREFIX_LENGTH;
+    name_length-= MYSQL50_TABLE_NAME_PREFIX_LENGTH;
+  }
+
   if (lower_case_table_names && name != any_db)
     my_casedn_str(files_charset_info, name);
 
-#if defined(USE_MB) && defined(USE_MB_IDENT)
-  if (use_mb(system_charset_info))
-  {
-    name_length= 0;
-    bool last_char_is_space= TRUE;
-    char *end= name + org_name->length;
-    while (name < end)
-    {
-      int len;
-      last_char_is_space= my_isspace(system_charset_info, *name);
-      len= my_ismbchar(system_charset_info, name, end);
-      if (!len)
-        len= 1;
-      name+= len;
-      name_length++;
-    }
-    return (last_char_is_space || name_length > NAME_CHAR_LEN);
-  }
-  else
-#endif
-    return ((org_name->str[org_name->length - 1] != ' ') ||
-            (name_length > NAME_CHAR_LEN)); /* purecov: inspected */
+  return check_table_name(name, name_length, check_for_path_chars);
 }
 
+
 /*
   Allow anything as a table name, as long as it doesn't contain an
   ' ' at the end
   returns 1 on error
 */
 
-
 bool check_table_name(const char *name, uint length, bool check_for_path_chars)
 {
   uint name_length= 0;  // name length in symbols
@@ -2754,10 +2740,10 @@ bool check_table_name(const char *name, uint length, bool check_for_path_chars)
         continue;
       }
     }
+#endif
     if (check_for_path_chars &&
         (*name == '/' || *name == '\\' || *name == '~' || *name == FN_EXTCHAR))
       return 1;
-#endif
     name++;
     name_length++;
   }