Fixes #8250.

Uncomplicates the examine pre-check.
Ensures door/examine() returns the proper value.

code/game/machinery/doors/door.dm

@@ -294,7 +294,7 @@
 
 
 /obj/machinery/door/examine(mob/user)
-	..()
+	. = ..()
 	if(src.health < src.maxhealth / 4)
 		user << "\The [src] looks like it's about to break!"
 	else if(src.health < src.maxhealth / 2)

code/game/machinery/doors/firedoor.dm

@@ -22,7 +22,7 @@
 	open_layer = DOOR_OPEN_LAYER - 0.01 // Just below doors when open
 	closed_layer = DOOR_CLOSED_LAYER + 0.01 // Just above doors when closed
 
-	//These are frequenly used with windows, so make sure zones can pass. 
+	//These are frequenly used with windows, so make sure zones can pass.
 	//Generally if a firedoor is at a place where there should be a zone boundery then there will be a regular door underneath it.
 	block_air_zones = 0
 
@@ -77,7 +77,8 @@
 
 
 /obj/machinery/door/firedoor/examine(mob/user)
-	if(!..(user, 1) && !isAI(user))
+	. = ..()
+	if(!. || !density)
 		return
 
 	if(pdiff >= FIREDOOR_MAX_PRESSURE_DIFF)
@@ -272,7 +273,7 @@
 				spawn(0)
 					close()
 			return
-		
+
 	return ..()
 
 // CHECK PRESSURE