Add minetest.override_item

builtin/misc_register.lua

@@ -315,6 +315,24 @@ minetest.register_item(":", {
 })
 
 
+function minetest.override_item(name, redefinition)
+	if redefinition.name ~= nil then
+		error("Attemt to redefine name of "..name.." to "..dump(redefinition.name), 2)
+	end
+	if redefinition.type ~= nil then
+		error("Attemt to redefine type of "..name.." to "..dump(redefinition.type), 2)
+	end
+	local item = minetest.registered_items[name]
+	if not item then
+		error("Attemt to override non-existent item "..name, 2)
+	end
+	for k, v in pairs(redefinition) do
+		rawset(item, k, v)
+	end
+	register_item_raw(item)
+end
+
+
 function minetest.run_callbacks(callbacks, mode, ...)
 	assert(type(callbacks) == "table")
 	local cb_len = #callbacks

doc/lua_api.txt

@@ -1189,6 +1189,10 @@ minetest.register_alias(name, convert_to)
 minetest.register_craft(recipe)
 minetest.register_ore(ore definition)
 minetest.register_decoration(decoration definition)
+minetest.override_item(name, redefinition)
+^ Overrides fields of an item registered with register_node/tool/craftitem.
+^ Note: Item must already be defined, (opt)depend on the mod defining it.
+^ Example: minetest.override_item("default:mese", {light_source=LIGHT_MAX})
 
 Global callback registration functions: (Call these only at load time)
 minetest.register_globalstep(func(dtime))