Merge pull request #4477 from Ccomp5950/runtimefixes

Runtimefixes

code/modules/mob/living/carbon/human/life.dm

@@ -325,7 +325,7 @@
 
 					breath = loc.remove_air(breath_moles)
 
-					if(istype(wear_mask, /obj/item/clothing/mask/gas))
+					if(istype(wear_mask, /obj/item/clothing/mask/gas) && breath)
 						var/obj/item/clothing/mask/gas/G = wear_mask
 						var/datum/gas_mixture/filtered = new
 

code/modules/projectiles/targeting.dm

@@ -269,7 +269,7 @@ client/proc/add_gun_icons()
 		screen += usr.gun_run_icon
 
 client/proc/remove_gun_icons()
-	if(isnull(usr)) return 1 // Runtime prevention on N00k agents spawning with SMG
+	if(!usr) return 1 // Runtime prevention on N00k agents spawning with SMG
 	screen -= usr.item_use_icon
 	screen -= usr.gun_move_icon
 	if (target_can_move)

code/modules/reagents/Chemistry-Reagents.dm

@@ -935,8 +935,9 @@ datum
 					for(var/mob/living/carbon/slime/M in T)
 						M.adjustToxLoss(rand(5,10))
 			reaction_turf(var/turf/simulated/S, var/volume)
-				if(volume >= 1)
-					S.dirt = 0
+				if(istype(S))
+					if(volume >= 1)
+						S.dirt = 0
 
 			reaction_mob(var/mob/M, var/method=TOUCH, var/volume)
 				if(iscarbon(M))
@@ -3699,4 +3700,4 @@ datum
 				return
 
 // Undefine the alias for REAGENTS_EFFECT_MULTIPLER
-#undef REM
+#undef REM