Adds a dna adder to head code so that head removal doesn't runtime ever

code/modules/organs/organ.dm

@@ -288,13 +288,14 @@ var/list/organ_cache = list()
 			take_damage(0,3)
 
 /obj/item/organ/proc/removed(var/mob/living/user)
-
 	if(!istype(owner))
 		return
 
-	owner.internal_organs_by_name[organ_tag] = null
-	owner.internal_organs_by_name -= organ_tag
-	owner.internal_organs_by_name -= null
+	if(is_primary_organ())
+		owner.internal_organs_by_name[organ_tag] = null
+		owner.internal_organs_by_name -= organ_tag
+		owner.internal_organs_by_name -= null // uh what does this line even do this seems silly
+
 	owner.internal_organs -= src
 
 	var/obj/item/organ/external/affected = owner.get_organ(parent_organ)
@@ -307,7 +308,7 @@ var/list/organ_cache = list()
 	if(!organ_blood || !organ_blood.data["blood_DNA"])
 		owner.vessel.trans_to(src, 5, 1, 1)
 
-	if(owner && vital)
+	if(owner && vital && is_primary_organ()) // I'd do another check for species or whatever so that you couldn't "kill" an IPC by removing a human head from them, but it doesn't matter since they'll come right back from the dead
 		if(user)
 			user.attack_log += "\[[time_stamp()]\]<font color='red'> removed a vital organ ([src]) from [key_name(owner)] (INTENT: [uppertext(user.a_intent)])</font>"
 			owner.attack_log += "\[[time_stamp()]\]<font color='orange'> had a vital organ ([src]) removed by [key_name(user)] (INTENT: [uppertext(user.a_intent)])</font>"
@@ -323,7 +324,8 @@ var/list/organ_cache = list()
 	processing_objects -= src
 	target.internal_organs |= src
 	affected.internal_organs |= src
-	target.internal_organs_by_name[organ_tag] = src
+	if (!(organ_tag in target.internal_organs_by_name))
+		target.internal_organs_by_name[organ_tag] = src // In case multiple of the same type are inserted, only the first one is the primary organ
 	src.loc = target
 	if(robotic)
 		status |= ORGAN_ROBOT
@@ -358,4 +360,16 @@ var/list/organ_cache = list()
 	qdel(src)
 
 /obj/item/organ/proc/surgeryize()
-	return
+	return
+
+/*
+Returns 1 if this is the organ that is handling all the functionalities of that particular organ slot
+Returns 0 if it isn't
+I use this so that this can be made better once the organ overhaul rolls out -- Crazylemon
+*/
+/obj/item/organ/proc/is_primary_organ(var/mob/living/carbon/human/O = null)
+	if (isnull(O))
+		O = owner
+	if (!istype(owner)) // You're not the primary organ of ANYTHING, bucko
+		return 0
+	return src == O.internal_organs_by_name[organ_tag]

code/modules/organs/organ_external.dm

@@ -859,7 +859,8 @@ Note that amputating the affected organ does in fact remove the infection from t
 
 	release_restraints(victim)
 	victim.organs -= src
-	victim.organs_by_name[limb_name] = null // Remove from owner's vars.
+	if(is_primary_organ(victim))
+		victim.organs_by_name[limb_name] = null	// Remove from owner's vars.
 
 	//Robotic limbs explode if sabotaged.
 	if(is_robotic && sabotaged)
@@ -889,3 +890,10 @@ Note that amputating the affected organ does in fact remove the infection from t
 			"\red <b>Your [name] melts away!</b>",	\
 			"\red You hear a sickening sizzle.")
 	disfigured = 1
+
+/obj/item/organ/external/is_primary_organ(var/mob/living/carbon/human/O = null)
+	if (isnull(O))
+		O = owner
+	if (!istype(O)) // You're not the primary organ of ANYTHING, bucko
+		return 0
+	return src == O.organs_by_name[limb_name]