diff -ur widelands-b13/src/events/event_factory.cc widelands-b13.patched//src/events/event_factory.cc
--- widelands-b13/src/events/event_factory.cc	2008-09-22 22:46:52.000000000 +0200
+++ widelands-b13.patched//src/events/event_factory.cc	2009-05-01 22:41:10.000000000 +0200
@@ -131,6 +131,7 @@
 	case 12: return *new Event_Unhide_Area     (name, state);
 	default:
 		assert(false);
+		return *new Event_Allow_Building  (name, state);
 	}
 }
 
diff -ur widelands-b13/src/map.h widelands-b13.patched//src/map.h
--- widelands-b13/src/map.h	2008-10-10 22:53:46.000000000 +0200
+++ widelands-b13.patched//src/map.h	2009-05-01 22:40:39.000000000 +0200
@@ -1038,6 +1038,7 @@
 	case Map_Object::WALK_W:  return  l_n(f);
 	default:
 		assert(false);
+		case Map_Object::WALK_NW: return tl_n(f);
 	}
 }
 
diff -ur widelands-b13/src/trigger/trigger_factory.cc widelands-b13.patched//src/trigger/trigger_factory.cc
--- widelands-b13/src/trigger/trigger_factory.cc	2008-09-22 22:46:52.000000000 +0200
+++ widelands-b13.patched//src/trigger/trigger_factory.cc	2009-05-01 22:40:23.000000000 +0200
@@ -93,6 +93,7 @@
 	case 5: return *new Trigger_Vision            (name, set);
 	default:
 		assert(false);
+		return *new Trigger_Building          (name, set);
 	}
 }