bugfix / tweaks (#6959)

code/game/objects/items/stacks/stack.dm

@@ -36,16 +36,19 @@
 	origin_tech = list(TECH_MATERIAL = 1)
 	icon = 'icons/obj/stacks.dmi'
 	item_flags = ITEM_CAREFUL_BLUDGEON | ITEM_ENCUMBERS_WHILE_HELD
+
+	/// Always create this type when splitting, instead of our own type.
+	var/split_type
+	/// The type we actually are. This is what is used when things try to consume an amount of us.
+	/// * null = this current type
+	var/stack_type
+
 	var/singular_name
 	var/amount = 1
 	/// See stack recipes initialisation, param "max_res_amount" must be equal to this max_amount.
 	var/max_amount = 50
 	/// Determines whether different stack types can merge.
-	var/stacktype
-	/// enforce a certain type when splitting; useful if you have an infinite stack you don't want to be split into another one
-	var/split_type
-	/// Used when directly applied to a turf.
-	var/build_type = null
+	var/stacktype_legacy
 	var/uses_charge = 0
 	var/list/charge_costs = null
 	var/list/datum/matter_synth/synths = null
@@ -70,8 +73,8 @@
 		explicit_recipes = typelist(NAMEOF(src, explicit_recipes), generate_explicit_recipes())
 	if(new_amount != null)
 		amount = new_amount
-	if(!stacktype)
-		stacktype = type
+	if(!stacktype_legacy)
+		stacktype_legacy = type
 	. = ..()
 	if(merge)
 		for(var/obj/item/stack/S in loc)
@@ -189,7 +192,7 @@
 		return FALSE
 	if((strict_color_stacking || other.strict_color_stacking) && (color != other.color))
 		return FALSE
-	return other.stacktype == stacktype
+	return other.stacktype_legacy == stacktype_legacy
 
 /obj/item/stack/proc/use(used)
 	if (!can_use(used))
@@ -424,3 +427,25 @@
 		return FALSE
 	update_icon()
 	return TRUE
+
+//* Types *//
+
+/**
+ * Get our 'use as type'.
+ */
+/obj/item/stack/proc/get_use_as_type()
+	return stack_type || type
+
+/**
+ * We can be used as a specific stack type.
+ */
+/obj/item/stack/proc/can_use_as_type(path)
+	return stack_type == path || type == path
+
+/**
+ * Can merge into a type
+ *
+ * todo: use this instead of raw stacktype_legacy checks
+ */
+/obj/item/stack/proc/can_merge_into_type(path)
+	CRASH("Not implemented.")