Hotfix issue preventing non-admins from presenceing

app/assets/javascripts/buttonhandlers.jsx.js

 	req = $.ajax(`/groups/${group}/activities/${activity}/presence`,
 		{
 		  method: 'PUT',
-		  data: {person_id: person, attending: state}
+		  data: {person_id: person, attending: state},
+		  statusCode: {
+			423: function() {
+				alert( "De deadline is al verstreken! Vraag orgi of bestuur of het nog kan.");
+			},
+			403: function() {
+				alert( "Je hebt geen rechten om iemand anders aan te passen!");
+			}
+		  }
 		}
 	)
-	.done( activity_changed )
-	.fail( alert_failure );
+	.done( activity_changed );
 
 	// Pack data for success
 	req.aardbei_activity_data =

app/controllers/activities_controller.rb

       person_id: params[:person_id],
       activity: @activity
     )
-    if !@activity.may_change?(current_person)
-      render status: :forbidden
+    if params[:person_id].to_i != current_person.id && !@activity.may_change?(current_person)
+      head :forbidden
+      return
+    end
+
+    if @activity.deadline && @activity.deadline < Time.now && !@activity.may_change?(current_person)
+      head :locked
+      return
     end
 
     if params[:participant]
       params[:notes] = params[:participant][:notes]
     end
     participant.update_attributes(params.permit(:notes, :attending))
+    head :no_content
   end
 
   def mass_new