Fixed a special case with simulated turfs being replaced by space.

Actually any unsimulated turf, but mostly space.

baystation12.int

@@ -1,6 +1,9 @@
 // BEGIN_INTERNALS
 /*
 MAP_ICON_TYPE: 0
+WINDOW: code\ZAS\Turf.dm;code\game\turfs\turf.dm;code\ZAS\Zone.dm
+DIR: code code\game code\game\turfs code\ZAS 
+FILE: code\game\turfs\turf.dm
 AUTO_FILE_DIR: OFF
 */
 // END_INTERNALS

code/game/turfs/turf.dm

@@ -216,6 +216,9 @@
 
 	var/old_lumcount = lighting_lumcount - initial(lighting_lumcount)
 
+	if(!ispath(N,/turf/simulated) && istype(src,/turf/simulated))
+		src:zone:remove(src)
+
 	if(ispath(N, /turf/simulated/floor))
 		//if the old turf had a zone, connect the new turf to it as well - Cael
 		//Adjusted by SkyMarshal 5/10/13 - The air master will handle the addition of the new turf.