check for databases after query

ChangeLog

@@ -10,7 +10,10 @@ $Source$
     * tbl_replace.php, tbl_replace_fields.php: Fixed #857445, #857684
       where non-existant fields caused PHP notices.
     * db_details.php: Removed unneccessary whitespace
-   
+    * sql.php: Bug #857742: When dropping the only remaining database, an
+      error occured. Fixed by checking if databases remein (as suggested
+      by lem9)
+                   
 2003-12-10 Garvin Hicking <me@supergarv.de>
     * db_datadict.php: Bug 857186: Real fix for the problem. The '@'
       delimiter slipped to the replacement's end instead of the expression's

sql.php

@@ -345,7 +345,7 @@ else {
         // This could happen if the user sends a query like "USE `database`;"
         $res = PMA_mysql_query('SELECT DATABASE() AS "db";');
         $row = PMA_mysql_fetch_array($res);
-        if ($db != $row['db']) {
+        if (is_array($row) && isset($row['db']) && $db != $row['db']) {
             $db     = $row['db'];
             $reload = 1;
         }