From 1a40fa73fbfcfd541407480d2c03bd2bfe9078ee Mon Sep 17 00:00:00 2001
From: deathride58 <deathride58@users.noreply.github.com>
Date: Wed, 17 Jun 2020 15:24:17 -0400
Subject: [PATCH] fixes an upstream oversight that completely bricks a
 downstream's atmos

---
 code/controllers/subsystem/air.dm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/code/controllers/subsystem/air.dm b/code/controllers/subsystem/air.dm
index d8c7724333..4d8bc3b1f6 100644
--- a/code/controllers/subsystem/air.dm
+++ b/code/controllers/subsystem/air.dm
@@ -76,6 +76,8 @@ SUBSYSTEM_DEF(air)
 		var/list/pipenet_rebuilds = pipenets_needing_rebuilt
 		for(var/thing in pipenet_rebuilds)
 			var/obj/machinery/atmospherics/AT = thing
+			if(!istype(AT))
+				continue
 			AT.build_network()
 		cost_rebuilds = MC_AVERAGE(cost_rebuilds, TICK_DELTA_TO_MS(TICK_USAGE_REAL - timer))
 		pipenets_needing_rebuilt.Cut()