identify the replacer that is to be set

fs_history.lua

@@ -101,6 +101,21 @@ end
 
 -- show a formspec with a history of stored patterns to select from
 replacer_setter.get_formspec = function(player_name, current_pattern, player)
+	local wield_index = player:get_wield_index()
+	local replacer_stack = nil
+	if(wield_index > 1) then
+		local inv = player:get_inventory()
+		replacer_stack = inv:get_stack("main", wield_index - 1)
+	end
+	if(not(replacer_stack) or replacer_stack:get_name() ~= "replacer:replacer") then
+		return "formspec_version[1]"..
+			"size[8,3]"..
+			"label[0.5,0.5;Please place your replacer in the slot *to the right*\n"..
+				"of this tool in your inventory! Else the replacer setter\n"..
+				"cannot know whichreplacer to set.]"..
+			"button_exit[3.5,2;1,1;exit;Exit]"
+	end
+
 	-- is the player in creative mode?
 	local in_creative_mode = (minetest.settings:get_bool("creative_mode")
 				or minetest.check_player_privs(player_name, {creative=true}))
@@ -191,7 +206,7 @@ minetest.register_on_player_receive_fields( function(player, formname, fields)
 			itemstack = replacer_setter.set_to(player_name,
 				replacer_setter.history[ player_name ][ selected.row ],
 				player, itemstack)
-			player:set_wielded_item(itemstack)
+			-- player:set_wielded_item(itemstack)
 			return true
 		end
 	end