* Prevent being able to open/close sleepers, cryo tubes and DNA scanners when in various conditions (weaken, ...) and by non-humans/non-silicons.

* Fixes possibles infinite loops runtime (#5527)

* Added icon updating on power changes/maintenance to Cryo Tubes and DNA Scanners
* Unpowered DNA Scanners can no longer be used if the associated computer is powered

* Cryo cells and sleepers won't work when powerless anymore

* Added an "is_operational" proc to machinery instead of duplicating the same check over and over.
* Cloning pods and DNA Scanners used by cloning computers won't work if powerless/broken/maintenance anymore.

Added an unpowered sprite for DNA Scanners, courtesy of Nienhaus

code/game/dna.dm

@@ -340,6 +340,7 @@
 	var/locked = 0
 	var/open = 0
 	anchored = 1
+	interact_offline = 1
 	use_power = 1
 	idle_power_usage = 50
 	active_power_usage = 300
@@ -371,6 +372,29 @@
 	for(var/obj/item/weapon/stock_parts/micro_laser/P in component_parts)
 		damage_coeff = P.rating
 
+/obj/machinery/dna_scannernew/update_icon()
+
+	//no power or maintenance
+	if(stat & (NOPOWER|BROKEN))
+		icon_state = initial(icon_state)+ (open ? "_open" : "") + "_unpowered"
+		return
+
+	if((stat & MAINT) || panel_open)
+		icon_state = initial(icon_state)+ (open ? "_open" : "") + "_maintenance"
+		return
+
+	//running and someone in there
+	if(occupant)
+		icon_state = initial(icon_state)+ "_occupied"
+		return
+
+	//running
+	icon_state = initial(icon_state)+ (open ? "_open" : "")
+
+/obj/machinery/dna_scannernew/power_change()
+	..()
+	update_icon()
+
 /obj/machinery/dna_scannernew/proc/toggle_open(mob/user=usr)
 	if(!user)
 		return
@@ -414,7 +438,7 @@
 			C.loc = src
 			C.stop_pulling()
 			break
-		icon_state = initial(icon_state) + (occupant ? "_occupied" : "")
+		update_icon()
 
 		// search for ghosts, if the corpse is empty and the scanner is connected to a cloner
 		if(occupant)
@@ -451,7 +475,7 @@
 					occupant.client.eye = occupant
 					occupant.client.perspective = MOB_PERSPECTIVE
 				occupant = null
-			icon_state = "[initial(icon_state)]_open"
+			update_icon()
 		return 1
 
 /obj/machinery/dna_scannernew/relaymove(mob/user as mob)
@@ -462,7 +486,8 @@
 
 /obj/machinery/dna_scannernew/attackby(obj/item/weapon/grab/G, mob/user)
 
-	if(!occupant && default_deconstruction_screwdriver(user, "[initial(icon_state)]_open", "[initial(icon_state)]", G))
+	if(!occupant && default_deconstruction_screwdriver(user, icon_state, icon_state, G))//sent icon_state is irrelevant...
+		update_icon()//..since we're updating the icon here, since the scanner can be unpowered when opened/closed
 		return
 
 	if(exchange_parts(user, G))
@@ -486,6 +511,8 @@
 	qdel(G)
 
 /obj/machinery/dna_scannernew/attack_hand(mob/user)
+	if(..())
+		return
 	toggle_open(user)
 	add_fingerprint(user)
 
@@ -578,7 +605,7 @@
 	var/occupant_status = "<div class='line'><div class='statusLabel'>Subject Status:</div><div class='statusValue'>"
 	var/scanner_status
 	var/temp_html
-	if(connected)
+	if(connected && connected.is_operational())
 		if(connected.occupant)	//set occupant_status message
 			viable_occupant = connected.occupant
 			if(check_dna_integrity(viable_occupant) && (!(NOCLONE in viable_occupant.mutations) || (connected.scan_level == 3)))	//occupent is viable for dna modification

code/game/machinery/Sleeper.dm

@@ -11,8 +11,9 @@
 	icon_state = "sleeper-open"
 	density = 0
 	anchored = 1
-	var/efficiency
+	interact_offline = 1
 	state_open = 1
+	var/efficiency
 	var/initial_bin_rating = 1
 	var/min_health = 25
 	var/list/injection_chems = list() //list of injectable chems except inaprovaline, coz inaprovaline is always avalible
@@ -132,11 +133,17 @@
 	open_machine()
 
 /obj/machinery/sleeper/attack_hand(mob/user)
-	if(stat & (BROKEN|NOPOWER))
+	if(..())
+		return
+
+	//powerless interaction
+	if(!is_operational())
+		user.unset_machine()//essential to prevent infinite loops of opening/closing the machine
 		if(state_open)
 			close_machine()
 		else
 			open_machine()
+
 	else
 		sleeperUI(user)
 
@@ -233,6 +240,8 @@
 		..(target)
 
 /obj/machinery/sleeper/proc/inject_chem(mob/user, chem)
+	if(!is_operational())
+		return
 	if(occupant && occupant.reagents)
 		if(chem in injection_chems + "inaprovaline")
 			if(occupant.reagents.get_reagent_amount(chem) + 10 <= 20 * efficiency)

code/game/machinery/cloning.dm

@@ -112,7 +112,7 @@
 /obj/machinery/clonepod/attack_paw(mob/user as mob)
 	return attack_hand(user)
 /obj/machinery/clonepod/attack_hand(mob/user as mob)
-	if ((isnull(src.occupant)) || (stat & NOPOWER))
+	if (isnull(src.occupant) || !is_operational())
 		return
 	if ((!isnull(src.occupant)) && (src.occupant.stat != 2))
 		var/completion = (100 * ((src.occupant.health + 100) / (src.heal_level + 100)))
@@ -205,7 +205,7 @@
 //Grow clones to maturity then kick them out.  FREELOADERS
 /obj/machinery/clonepod/process()
 
-	if(stat & NOPOWER) //Autoeject if power is lost
+	if(!is_operational()) //Autoeject if power is lost
 		if (src.occupant)
 			src.locked = 0
 			src.go_out()

code/game/machinery/computer/cloning.dm

@@ -54,12 +54,12 @@
 		// Try to find a scanner in that direction
 		scannerf = locate(/obj/machinery/dna_scannernew, get_step(src, dir))
 
-		// If found, then we break, and return the scanner
-		if (!isnull(scannerf))
-			break
+		// If found and operational, return the scanner
+		if (!isnull(scannerf) && scannerf.is_operational())
+			return scannerf
 
 	// If no scanner was found, it will return null
-	return scannerf
+	return null
 
 /obj/machinery/computer/cloning/proc/findcloner()
 	var/obj/machinery/clonepod/podf = null
@@ -68,10 +68,10 @@
 
 		podf = locate(/obj/machinery/clonepod, get_step(src, dir))
 
-		if (!isnull(podf))
-			break
+		if (!isnull(podf) && podf.is_operational())
+			return podf
 
-	return podf
+	return null
 
 /obj/machinery/computer/cloning/attackby(obj/item/W as obj, mob/user as mob)
 	if (istype(W, /obj/item/weapon/disk/data)) //INSERT SOME DISKETTES
@@ -233,25 +233,25 @@
 			if("stopautoprocess")
 				autoprocess = 0
 
-	else if ((href_list["scan"]) && (!isnull(src.scanner)))
+	else if ((href_list["scan"]) && !isnull(scanner) && scanner.is_operational())
 		scantemp = ""
 
 		loading = 1
 		src.updateUsrDialog()
 
 		spawn(20)
-			src.scan_mob(src.scanner.occupant)
+			src.scan_mob(scanner.occupant)
 
 			loading = 0
 			src.updateUsrDialog()
 
 
 		//No locking an open scanner.
-	else if ((href_list["lock"]) && (!isnull(src.scanner)))
-		if ((!src.scanner.locked) && (src.scanner.occupant))
-			src.scanner.locked = 1
+	else if ((href_list["lock"]) && !isnull(scanner) && scanner.is_operational())
+		if ((!scanner.locked) && (scanner.occupant))
+			scanner.locked = 1
 		else
-			src.scanner.locked = 0
+			scanner.locked = 0
 
 	else if(href_list["view_rec"])
 		src.active_record = find_record("id", href_list["view_rec"], records)

code/game/machinery/cryo.dm

@@ -4,6 +4,7 @@
 	icon_state = "cell-off"
 	density = 1
 	anchored = 1.0
+	interact_offline = 1
 	layer = 4
 
 	var/on = 0
@@ -45,7 +46,7 @@
 
 /obj/machinery/atmospherics/unary/cryo_cell/process()
 	..()
-	if(!node)
+	if(!node || !is_operational())
 		return
 	if(!on)
 		updateDialog()
@@ -97,11 +98,17 @@
 		user << "Seems empty."
 
 /obj/machinery/atmospherics/unary/cryo_cell/attack_hand(mob/user)
-	if(stat & (NOPOWER|BROKEN))
-		if(state_open == 1)
+	if(..())
+		return
+
+	//powerless interaction
+	if(!is_operational())
+		user.unset_machine()//essential to prevent infinite loops of opening/closing the machine
+		if(state_open)
 			close_machine()
 		else
 			open_machine()
+
 	else
 		ui_interact(user)
 
@@ -258,7 +265,7 @@
 	if(state_open)
 		icon_state = "cell-open"
 		return
-	if(on)
+	if(on && is_operational())
 		if(occupant)
 			icon_state = "cell-occupied"
 		else
@@ -266,6 +273,9 @@
 	else
 		icon_state = "cell-off"
 
+/obj/machinery/atmospherics/unary/cryo_cell/power_change()
+	..()
+	update_icon()
 
 /obj/machinery/atmospherics/unary/cryo_cell/proc/process_occupant()
 	if(air_contents.total_moles() < 10)

code/game/machinery/machinery.dm

@@ -84,6 +84,8 @@ Class Procs:
    process()                  'game/machinery/machine.dm'
       Called by the 'master_controller' once per game tick for each machine that is listed in the 'machines' list.
 
+	is_operational()
+		Returns 0 if the machine is unpowered, broken or undergoing maintenance, 1 if not
 
 	Compiled by Aygar
 */
@@ -209,6 +211,11 @@ Class Procs:
 	add_fingerprint(usr)
 	return 0
 
+/obj/machinery/proc/is_operational()
+	return !(stat & (NOPOWER|BROKEN|MAINT))
+
+////////////////////////////////////////////////////////////////////////////////////////////
+
 /mob/proc/canUseTopic() //TODO: once finished, place these procs on the respective mob files
 	return