Braining/debraining fixes

code/modules/mob/living/brain/brain.dm

@@ -28,6 +28,8 @@
 	if(key)				//If there is a mob connected to this thing. Have to check key twice to avoid false death reporting.
 		if(stat!=DEAD)	//If not dead.
 			death(1)	//Brains can die again. AND THEY SHOULD AHA HA HA HA HA HA
+		if(mind)	//You aren't allowed to return to brains that don't exist
+			mind.current = null
 		ghostize()		//Ghostize checks for key so nothing else is necessary.
 	container = null
 	return ..()

code/modules/mob/living/brain/brain_item.dm

@@ -7,16 +7,29 @@
 	layer = ABOVE_MOB_LAYER
 	zone = "head"
 	slot = "brain"
-	vital = 1
+	vital = TRUE
 	origin_tech = "biotech=5"
 	attack_verb = list("attacked", "slapped", "whacked")
 	var/mob/living/brain/brainmob = null
 	var/damaged_brain = FALSE //whether the brain organ is damaged.
 	var/decoy_override = FALSE	//I apologize to the security players, and myself, who abused this, but this is going to go.
 
+/obj/item/organ/brain/changeling_brain
+	vital = FALSE
+	decoy_override = TRUE
+
 /obj/item/organ/brain/Insert(mob/living/carbon/C, special = 0)
 	..()
+
 	name = "brain"
+
+	if(C.mind && C.mind.changeling)	//congrats, you're trapped in a body you don't control
+		if(brainmob && !(C.stat == DEAD || (C.status_flags & FAKEDEATH)))
+			to_chat(brainmob, "<span class = danger>You can't feel your body! You're still just a brain!</span>")
+		loc = C
+		C.update_hair()
+		return
+
 	if(brainmob)
 		if(C.key)
 			C.ghostize()
@@ -26,7 +39,7 @@
 		else
 			C.key = brainmob.key
 
-		qdel(brainmob)
+		QDEL_NULL(brainmob)
 
 	//Update the body's icon so it doesnt appear debrained anymore
 	C.update_hair()
@@ -37,7 +50,7 @@
 		if(C.has_brain_worms())
 			var/mob/living/simple_animal/borer/B = C.has_brain_worms()
 			B.leave_victim() //Should remove borer if the brain is removed - RR
-		transfer_identity(C)
+	transfer_identity(C)
 	C.update_hair()
 
 /obj/item/organ/brain/prepare_eat()
@@ -45,6 +58,8 @@
 
 /obj/item/organ/brain/proc/transfer_identity(mob/living/L)
 	name = "[L.name]'s brain"
+	if(brainmob || decoy_override)
+		return
 	brainmob = new(src)
 	brainmob.name = L.real_name
 	brainmob.real_name = L.real_name
@@ -54,7 +69,7 @@
 		if(!brainmob.stored_dna)
 			brainmob.stored_dna = new /datum/dna/stored(brainmob)
 		C.dna.copy_dna(brainmob.stored_dna)
-	if(L.mind && L.mind.current && (L.mind.current.stat == DEAD))
+	if(L.mind && L.mind.current)
 		L.mind.transfer_to(brainmob)
 	to_chat(brainmob, "<span class='notice'>You feel slightly disoriented. That's normal when you're just a brain.</span>")