catch dropped

code/__DEFINES/dcs/signals.dm

@@ -241,6 +241,8 @@
 #define COMSIG_ITEM_ALT_AFTERATTACK "item_alt_afterattack"		//from base of obj/item/altafterattack(): (atom/target, mob/user, proximity, params)
 #define COMSIG_ITEM_EQUIPPED "item_equip"						//from base of obj/item/equipped(): (/mob/equipper, slot)
 #define COMSIG_ITEM_DROPPED "item_drop"							//from base of obj/item/dropped(): (mob/user)
+	// relocated, tell inventory procs if those called this that the item isn't available anymore.
+	#define COMPONENT_DROPPED_RELOCATION 1
 #define COMSIG_ITEM_PICKUP "item_pickup"						//from base of obj/item/pickup(): (/mob/taker)
 #define COMSIG_ITEM_ATTACK_ZONE "item_attack_zone"				//from base of mob/living/carbon/attacked_by(): (mob/living/carbon/target, mob/living/user, hit_zone)
 #define COMSIG_ITEM_IMBUE_SOUL "item_imbue_soul" 				//return a truthy value to prevent ensouling, checked in /obj/effect/proc_holder/spell/targeted/lichdom/cast(): (mob/user)

code/__DEFINES/misc/return_values.dm

@@ -0,0 +1,3 @@
+// obj/item/dropped
+/// dropped() relocated this item, return FALSE for doUnEquip.
+#define ITEM_RELOCATED_BY_DROPPED			"relocated_by_dropped"

code/game/objects/items.dm

@@ -392,7 +392,8 @@ GLOBAL_VAR_INIT(rpg_loot_items, FALSE)
 	if(item_flags & DROPDEL)
 		qdel(src)
 	item_flags &= ~IN_INVENTORY
-	SEND_SIGNAL(src, COMSIG_ITEM_DROPPED,user)
+	if(SEND_SIGNAL(src, COMSIG_ITEM_DROPPED,user) & COMPONENT_DROPPED_RELOCATION)
+		return ITEM_RELOCATED_BY_DROPPED
 	user.update_equipment_speed_mods()
 
 // called just as an item is picked up (loc is not yet changed)

code/modules/mob/inventory.dm

@@ -333,7 +333,8 @@
 				I.moveToNullspace()
 			else
 				I.forceMove(newloc)
-		I.dropped(src)
+		if(I.dropped(src) == ITEM_RELOCATED_BY_DROPPED)
+			return FALSE
 	return TRUE
 
 //Outdated but still in use apparently. This should at least be a human proc.

code/modules/surgery/organs/augments_arms.dm

@@ -33,6 +33,7 @@
 	RegisterSignal(I, COMSIG_ITEM_DROPPED, .proc/magnetic_catch)
 
 /obj/item/organ/cyberimp/arm/proc/magnetic_catch(datum/source, mob/user)
+	. = COMPONENT_DROPPED_RELOCATION
 	var/obj/item/I = source			//if someone is misusing the signal, just runtime
 	if(I in items_list)
 		if(I in contents)		//already in us somehow? i probably shouldn't catch this so it's easier to spot bugs but eh..