Another stack of runtime errors dealt with.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@260 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/objects/assemblies.dm

@@ -79,8 +79,9 @@
 			if(href_list["open"])
 				toggle_valve()
 			if(href_list["rem_device"])
-				attached_device.loc = get_turf(src)
-				attached_device = null
+				if(attached_device)
+					attached_device.loc = get_turf(src)
+					attached_device = null
 				update_icon()
 			if(href_list["device"])
 				attached_device.attack_self(usr)

code/game/objects/devices/PDA.dm

@@ -1206,30 +1206,31 @@ Code:
 
 		else if (href_list["detonate"] && istype(src.cartridge, /obj/item/weapon/cartridge/syndicate))
 			var/obj/item/device/pda/P = locate(href_list["detonate"])
-			if (!P.toff && src.cartridge:shock_charges > 0)
-				src.cartridge:shock_charges--
+			if(P)
+				if (!P.toff && src.cartridge:shock_charges > 0)
+					src.cartridge:shock_charges--
 
-				var/difficulty = 0
+					var/difficulty = 0
 
-				if (!isnull(P.cartridge))
-					difficulty += P.cartridge.access_medical
-					difficulty += P.cartridge.access_security
-					difficulty += P.cartridge.access_engine
-					difficulty += P.cartridge.access_clown
-					difficulty += P.cartridge.access_janitor
-					difficulty += P.cartridge.access_manifest * 2
-				else
-					difficulty += 2
+					if (!isnull(P.cartridge))
+						difficulty += P.cartridge.access_medical
+						difficulty += P.cartridge.access_security
+						difficulty += P.cartridge.access_engine
+						difficulty += P.cartridge.access_clown
+						difficulty += P.cartridge.access_janitor
+						difficulty += P.cartridge.access_manifest * 2
+					else
+						difficulty += 2
 
-				if ((prob(difficulty * 12)) || (P.uplink))
-					usr.show_message("\red An error flashes on your [src].", 1)
-				else if (prob(difficulty * 3))
-					usr.show_message("\red Energy feeds back into your [src]!", 1)
-					src.explode()
-				else
-					usr.show_message("\blue Success!", 1)
-					P.explode()
-			src.updateUsrDialog()
+					if ((prob(difficulty * 12)) || (P.uplink))
+						usr.show_message("\red An error flashes on your [src].", 1)
+					else if (prob(difficulty * 3))
+						usr.show_message("\red Energy feeds back into your [src]!", 1)
+						src.explode()
+					else
+						usr.show_message("\blue Success!", 1)
+						P.explode()
+				src.updateUsrDialog()
 
 		else if (href_list["sendhonk"] && istype(src.cartridge, /obj/item/weapon/cartridge/clown))
 			var/obj/item/device/pda/P = locate(href_list["sendhonk"])

code/game/objects/items/weapons/mops_cleaners.dm

@@ -71,9 +71,10 @@ MOP
 		for(var/mob/O in viewers(user, null))
 			O.show_message(text("\red <B>[user] begins to clean [A]</B>"), 1)
 		sleep(20)
-		user << "\blue You have finished mopping!"
-		var/turf/U = A.loc
-		src.reagents.reaction(U)
+		if(A)
+			user << "\blue You have finished mopping!"
+			var/turf/U = A.loc
+			src.reagents.reaction(U)
 		if(A) del(A)
 		mopcount++
 

code/game/objects/structures.dm

@@ -92,15 +92,16 @@ obj/structure
 		if (src.icon_state == "reinforced") //Time to finalize!
 			user << "\blue Now finalising reinforced wall."
 			sleep(50)
-			if(get_turf(user) == T)
-				user << "\blue Wall fully reinforced!"
-				var/turf/Tsrc = get_turf(src)
-				Tsrc.ReplaceWithRWall()
-				W:amount--
-				if (W:amount <= 0)
-					del(W)
-				del(src)
-				return
+			if(W)
+				if(get_turf(user) == T)
+					user << "\blue Wall fully reinforced!"
+					var/turf/Tsrc = get_turf(src)
+					Tsrc.ReplaceWithRWall()
+					W:amount--
+					if (W:amount <= 0)
+						del(W)
+					del(src)
+					return
 		else
 			user << "\blue Now reinforcing girders"
 			sleep(60)

code/game/objects/tank.dm

@@ -434,11 +434,13 @@
 			return
 		var/obj/item/assembly/t_i_ptank/R = new /obj/item/assembly/t_i_ptank( user )
 		R.part1 = S.part1
-		S.part1.loc = R
-		S.part1.master = R
+		if (S.part1)
+			S.part1.loc = R
+			S.part1.master = R
 		R.part2 = S.part2
-		S.part2.loc = R
-		S.part2.master = R
+		if (S.part2)
+			S.part2.loc = R
+			S.part2.master = R
 		S.layer = initial(S.layer)
 		if (user.client)
 			user.client.screen -= S