Fix: Bespoke DCS elements use all requested args. (#26387)

code/__DEFINES/dcs/dcs_flags.dm

@@ -12,7 +12,7 @@
 /// Causes the detach proc to be called when the host object is being deleted
 #define ELEMENT_DETACH_ON_HOST_DESTROY		(1 << 0)
 /**
-  * Only elements created with the same arguments given after `id_arg_index` share an element instance
+  * Only elements created with the same arguments given after `argument_hash_start_idx` share an element instance
   * The arguments are the same when the text and number values are the same and all other values have the same ref
   */
 #define ELEMENT_BESPOKE		(1 << 1)

code/controllers/subsystem/processing/SSdcs.dm

@@ -34,7 +34,7 @@ PROCESSING_SUBSYSTEM_DEF(dcs)
 	var/datum/element/eletype = arguments[1]
 	var/list/fullid = list(eletype)
 	var/list/named_arguments
-	for(var/i in initial(eletype.id_arg_index) to (initial(eletype.id_arg_index) || length(arguments)))
+	for(var/i in initial(eletype.argument_hash_start_idx) to (initial(eletype.argument_hash_end_idx) || length(arguments)))
 		var/key = arguments[i]
 
 		if(istext(key))

code/datums/elements/_element.dm

@@ -10,11 +10,21 @@
 	/**
 	  * The index of the first attach argument to consider for duplicate elements
 	  *
+	  * All arguments from this index onwards (1 based, until `argument_hash_end_idx` is reached, if set)
+	  * are hashed into the key to determine if this is a new unique element or one already exists
+	  *
 	  * Is only used when flags contains [ELEMENT_BESPOKE]
 	  *
 	  * This is infinity so you must explicitly set this
 	  */
-	var/id_arg_index = INFINITY
+	var/argument_hash_start_idx = INFINITY
+
+	/**
+	  * The index of the last attach argument to consider for duplicate elements
+	  * Only used when `element_flags` contains [ELEMENT_BESPOKE].
+	  * If not set, it'll copy every argument from `argument_hash_start_idx` onwards as normal
+	  */
+	var/argument_hash_end_idx = 0
 
 /// Activates the functionality defined by the element on the given target datum
 /datum/element/proc/Attach(datum/target)

code/datums/elements/rad_insulation.dm

@@ -1,6 +1,6 @@
 /datum/element/rad_insulation
 	element_flags = ELEMENT_DETACH_ON_HOST_DESTROY | ELEMENT_BESPOKE
-	id_arg_index = 2
+	argument_hash_start_idx = 2
 	var/amount					// Multiplier for radiation strength passing through
 
 /datum/element/rad_insulation/Attach(datum/target, _amount = RAD_MEDIUM_INSULATION, protects = TRUE, contamination_proof = TRUE)

code/datums/elements/ridable.dm

@@ -8,7 +8,7 @@
  */
 /datum/element/ridable
 	element_flags = ELEMENT_BESPOKE
-	id_arg_index = 2
+	argument_hash_start_idx = 2
 	/// The specific riding component subtype we're loading our instructions from, don't leave this as default please!
 	var/riding_component_type = /datum/component/riding
 	/// If we have a xenobio red potion applied to us, we get split off so we can pass our special status onto new riding components

code/datums/elements/shatters_when_thrown.dm

@@ -3,7 +3,7 @@
  */
 /datum/element/shatters_when_thrown
 	element_flags = ELEMENT_BESPOKE
-	id_arg_index = 2
+	argument_hash_start_idx = 2
 	/// What type of item is spawned as a 'shard' once the shattering happens
 	var/obj/item/shard_type
 	/// How many shards total are made when the thing we're attached to shatters

code/datums/elements/strippable.dm

@@ -3,7 +3,7 @@
 /// An element for atoms that, when dragged and dropped onto a mob, opens a strip panel.
 /datum/element/strippable
 	element_flags = ELEMENT_BESPOKE | ELEMENT_DETACH_ON_HOST_DESTROY
-	id_arg_index = 2
+	argument_hash_start_idx = 2
 
 	/// An assoc list of keys to /datum/strippable_item
 	var/list/items

code/modules/unit_tests/element_tests.dm

@@ -1,4 +1,4 @@
 /datum/unit_test/bespoke_element/Run()
 	for(var/datum/element/element_type as anything in subtypesof(/datum/element))
-		if(initial(element_type.element_flags) & ELEMENT_BESPOKE && initial(element_type.id_arg_index) == INFINITY)
-			Fail("Element type [element_type] has ELEMENT_BESPOKE and a default id_arg_index.")
+		if(initial(element_type.element_flags) & ELEMENT_BESPOKE && initial(element_type.argument_hash_start_idx) == INFINITY)
+			Fail("Element type [element_type] has ELEMENT_BESPOKE and a default argument_hash_start_idx.")