fix two bugs in MDB2, patches committed upstream https://pear.php.net/bugs/bug.php?id=19582

3rdparty/MDB2/Driver/Datatype/Common.php

@@ -1412,7 +1412,7 @@ class MDB2_Driver_Datatype_Common extends MDB2_Module_Common
             if (PEAR::isError($db)) {
                 return $db;
             }
-            if (isset($db->function) && is_object($this->function) && is_a($db->function, 'MDB2_Driver_Function_Common')) {
+            if (isset($db->function) && is_object($db->function) && is_a($db->function, 'MDB2_Driver_Function_Common')) {
                 return $db->function->now('timestamp');
             }
             return 'CURRENT_TIMESTAMP';

3rdparty/MDB2/Driver/mysql.php

@@ -80,7 +80,7 @@ class MDB2_Driver_mysql extends MDB2_Driver_Common
 
     protected $start_transaction = false;
 
-    protected $varchar_max_length = 255;
+    public $varchar_max_length = 255;
 
     // }}}
     // {{{ constructor