GMap extended views style: Notice: Undefined index

Similar to node/1255514 i got this warnings:

Notice: Undefined index: coordinates in template_preprocess_gmap_views_view_gmapextended() (Zeile 60 von sites/all/modules/gmap/gmap.views.inc).
Notice: Undefined index: city in template_preprocess_gmap_views_view_gmapextended() (Zeile 60 von sites/all/modules/gmap/gmap.views.inc).

The dirty fix for me was to check if $row[index] was set. On line 56 in gmap.views.inc i added:

if (!isset($row[$field])) {
          $row[$field]='';
      }