PHP notices on widget type edit screen

Notice: Trying to get property of non-object in hs_taxonomy_form_field_ui_widget_type_form_alter() (line 47 of sites/all/modules/contrib/hierarchical_select/modules/hs_taxonomy.module).
Notice: Trying to get property of non-object in hs_taxonomy_form_field_ui_widget_type_form_alter() (line 62 of sites/all/modules/contrib/hierarchical_select/modules/hs_taxonomy.module).

Getting these errors on widget edit form when no vocabulary has been set for the field. Not too sure about the best approach for this, but could easily do something like this patch.