diff --git a/libraries/DatabaseInterface.class.php b/libraries/DatabaseInterface.class.php
index 724a3315de..e3c8cd2865 100644
--- a/libraries/DatabaseInterface.class.php
+++ b/libraries/DatabaseInterface.class.php
@@ -91,8 +91,8 @@ class PMA_DatabaseInterface
      * Caches table data so PMA_Table does not require to issue
      * SHOW TABLE STATUS again
      *
-     * @param array       $tables information for tables of some databases
-     * @param string|bool $table  table name or false
+     * @param array  $tables information for tables of some databases
+     * @param string $table  table name
      *
      * @return void
      */
@@ -304,16 +304,16 @@ class PMA_DatabaseInterface
     /**
      * returns a segment of the SQL WHERE clause regarding table name and type
      *
-     * @param string|bool $table        table or false
-     * @param boolean     $tbl_is_group $table is a table group
-     * @param string      $table_type   whether table or view
+     * @param string  $table        table
+     * @param boolean $tbl_is_group $table is a table group
+     * @param string  $table_type   whether table or view
      *
      * @return string a segment of the WHERE clause
      */
     private function _getTableCondition($table, $tbl_is_group, $table_type)
     {
         // get table information from information_schema
-        if ($table && is_string($table)) {
+        if ($table) {
             if (true === $tbl_is_group) {
                 $sql_where_table = 'AND t.`TABLE_NAME` LIKE \''
                     . PMA_Util::escapeMysqlWildcards(
@@ -445,7 +445,7 @@ class PMA_DatabaseInterface
      * </code>
      *
      * @param string          $database     database
-     * @param string|bool     $table        table name or false
+     * @param string          $table        table name
      * @param boolean         $tbl_is_group $table is a table group
      * @param mixed           $link         mysql link
      * @param integer         $limit_offset zero-based offset for the count
@@ -458,7 +458,7 @@ class PMA_DatabaseInterface
      *
      * @return array           list of tables in given db(s)
      */
-    public function getTablesFull($database, $table = false,
+    public function getTablesFull($database, $table = '',
         $tbl_is_group = false,  $link = null, $limit_offset = 0,
         $limit_count = false, $sort_by = 'Name', $sort_order = 'ASC',
         $table_type = null
diff --git a/libraries/Util.class.php b/libraries/Util.class.php
index 0c11678d0d..6cd6787469 100644
--- a/libraries/Util.class.php
+++ b/libraries/Util.class.php
@@ -757,7 +757,7 @@ class PMA_Util
 
         if ($tables === null) {
             $tables = $GLOBALS['dbi']->getTablesFull(
-                $db, false, false, null, $limit_offset, $limit_count
+                $db, '', false, null, $limit_offset, $limit_count
             );
             if ($GLOBALS['cfg']['NaturalOrder']) {
                 uksort($tables, 'strnatcasecmp');
diff --git a/libraries/tbl_relation.lib.php b/libraries/tbl_relation.lib.php
index 8179b05608..44faf5c94e 100644
--- a/libraries/tbl_relation.lib.php
+++ b/libraries/tbl_relation.lib.php
@@ -1108,24 +1108,24 @@ function PMA_handleUpdateForForeignKey($multi_edit_columns_name, $master_field_m
                         $existrel_foreign[$master_field_md5]['on_update'])
                         ? $existrel_foreign[$master_field_md5]['on_update']
                         : 'RESTRICT';
-        }
 
-        if (! isset($existrel_foreign[$master_field_md5])) {
+            if ($ref_db_name != $foreign_db
+                || $existrel_foreign[$master_field_md5]['ref_table_name'] != $foreign_table
+                || $existrel_foreign[$master_field_md5]['ref_index_list'] != $foreign_field
+                || $existrel_foreign[$master_field_md5]['index_list'] != $master_field
+                || $_REQUEST['constraint_name'][$master_field_md5] != $constraint_name
+                || ($_REQUEST['on_delete'][$master_field_md5] != $on_delete)
+                || ($_REQUEST['on_update'][$master_field_md5] != $on_update)
+            ) {
+                // another foreign key is already defined for this field
+                // or an option has been changed for ON DELETE or ON UPDATE
+                $drop = true;
+                $create = true;
+            } // end if... else....
+        } else {
             // no key defined for this field(s)
             $create = true;
-        } elseif ($ref_db_name != $foreign_db
-            || $existrel_foreign[$master_field_md5]['ref_table_name'] != $foreign_table
-            || $existrel_foreign[$master_field_md5]['ref_index_list'] != $foreign_field
-            || $existrel_foreign[$master_field_md5]['index_list'] != $master_field
-            || $_REQUEST['constraint_name'][$master_field_md5] != $constraint_name
-            || ($_REQUEST['on_delete'][$master_field_md5] != $on_delete)
-            || ($_REQUEST['on_update'][$master_field_md5] != $on_update)
-        ) {
-            // another foreign key is already defined for this field
-            // or an option has been changed for ON DELETE or ON UPDATE
-            $drop = true;
-            $create = true;
-        } // end if... else....
+        }
     } elseif (isset($existrel_foreign[$master_field_md5])) {
         $drop = true;
     } // end if... else....