Fixes Novaflowers not lighting people on fire, again. Unit tests it. Cleans up some unique plant genes stuff too. (#67597)

code/datums/elements/plant_backfire.dm

@@ -3,7 +3,7 @@
 /// If a user is protected with something like leather gloves, they can handle them normally.
 /// If they're not protected properly, we invoke a callback on the user, harming or inconveniencing them.
 /datum/element/plant_backfire
-	element_flags = ELEMENT_BESPOKE | ELEMENT_DETACH
+	element_flags = ELEMENT_BESPOKE
 	id_arg_index = 2
 	/// Whether we stop the current action if backfire is triggered (EX: returning CANCEL_ATTACK_CHAIN)
 	var/cancel_action = FALSE
@@ -29,52 +29,67 @@
 	. = ..()
 	UnregisterSignal(target, list(COMSIG_ITEM_PRE_ATTACK, COMSIG_ITEM_PICKUP, COMSIG_MOVABLE_PRE_THROW))
 
-/*
+/**
  * Checks before we attack if we're okay to continue.
  *
  * source - our plant
  * user - the mob wielding our [source]
  */
-/datum/element/plant_backfire/proc/attack_safety_check(datum/source, atom/target, mob/user)
+/datum/element/plant_backfire/proc/attack_safety_check(obj/item/source, atom/target, mob/user)
 	SIGNAL_HANDLER
 
-	if(plant_safety_check(source, user))
+	// Covers stuff like tk, since we aren't actually touching the plant.
+	if(!user.is_holding(source))
+		return
+	if(!backfire(source, user))
 		return
-	
-	SEND_SIGNAL(source, COMSIG_PLANT_ON_BACKFIRE, user)
-	if(cancel_action)
-		return COMPONENT_CANCEL_ATTACK_CHAIN
 
-/*
+	return cancel_action ? COMPONENT_CANCEL_ATTACK_CHAIN : NONE
+
+/**
  * Checks before we pick up the plant if we're okay to continue.
  *
  * source - our plant
  * user - the mob picking our [source]
  */
-/datum/element/plant_backfire/proc/pickup_safety_check(datum/source, mob/user)
+/datum/element/plant_backfire/proc/pickup_safety_check(obj/item/source, mob/user)
 	SIGNAL_HANDLER
 
-	if(plant_safety_check(source, user))
-		return
-	SEND_SIGNAL(source, COMSIG_PLANT_ON_BACKFIRE, user)
+	backfire(source, user)
 
-/*
+/**
  * Checks before we throw the plant if we're okay to continue.
  *
  * source - our plant
  * thrower - the mob throwing our [source]
  */
-/datum/element/plant_backfire/proc/throw_safety_check(datum/source, list/arguments)
+/datum/element/plant_backfire/proc/throw_safety_check(obj/item/source, list/arguments)
 	SIGNAL_HANDLER
 
-	var/mob/living/thrower = arguments[4] // 4th arg = mob/thrower
-	if(plant_safety_check(source, thrower))
+	var/mob/living/thrower = arguments[4] // the 4th arg = the mob throwing our item
+	if(!thrower.is_holding(source))
+		return
+	if(!backfire(source, thrower))
 		return
-	SEND_SIGNAL(source, COMSIG_PLANT_ON_BACKFIRE, thrower)
-	if(cancel_action)
-		return COMPONENT_CANCEL_THROW
 
-/*
+	return cancel_action ? COMPONENT_CANCEL_ATTACK_CHAIN : NONE
+
+/**
+ * The actual backfire occurs here.
+ * Checks if the user is able to safely handle the plant.
+ * If not, sends the backfire signal (meaning backfire will occur and be handled by one or multiple genes).
+ *
+ * Returns FALSE if the user was safe and no backfire occured.
+ * Returns TRUE if the user was not safe and a backfire actually happened.
+ */
+/datum/element/plant_backfire/proc/backfire(obj/item/plant, mob/user)
+	if(plant_safety_check(plant, user))
+		return FALSE
+
+	SEND_SIGNAL(plant, COMSIG_PLANT_ON_BACKFIRE, user)
+	return TRUE
+
+/**
  * Actually checks if our user is safely handling our plant.
  *
  * Checks for TRAIT_PLANT_SAFE, and returns TRUE if we have it.
@@ -86,13 +101,10 @@
  *
  * returns FALSE if none of the checks are successful.
  */
-/datum/element/plant_backfire/proc/plant_safety_check(datum/source, mob/living/carbon/user)
+/datum/element/plant_backfire/proc/plant_safety_check(obj/item/plant, mob/living/carbon/user)
 	if(!istype(user))
 		return TRUE
 
-	if(istype(source, /obj/item/tk_grab)) // since we aren't actually touching the plant
-		return TRUE
-
 	if(HAS_TRAIT(user, TRAIT_PLANT_SAFE))
 		return TRUE
 
@@ -100,8 +112,7 @@
 		if(HAS_TRAIT(user, checked_trait))
 			return TRUE
 
-	var/obj/item/parent_item = source
-	var/obj/item/seeds/our_seed = parent_item.get_plant_seed()
+	var/obj/item/seeds/our_seed = plant.get_plant_seed()
 	if(our_seed)
 		for(var/checked_gene in extra_genes)
 			if(!our_seed.get_gene(checked_gene))

code/datums/status_effects/debuffs/fire_stacks.dm

@@ -220,6 +220,7 @@
 	SEND_SIGNAL(owner, COMSIG_LIVING_IGNITED, owner)
 	cache_stacks()
 	update_overlay()
+	return TRUE
 
 /**
  * Handles mob extinguishing, should be the only way to set on_fire to FALSE