+function core.override_item(name, redefinition)
+ if redefinition.name ~= nil then
+ error("Attempt to redefine name of "..name.." to "..dump(redefinition.name), 2)
+ end
+ if redefinition.type ~= nil then
+ error("Attempt to redefine type of "..name.." to "..dump(redefinition.type), 2)
+ end
+ local itemdef = core.get_item_def(name)
+ if not itemdef then
+ error("Attempt to override non-existent item "..name, 2)
+ end
+ local nodedef = core.get_node_def(name)
+ table.combine(itemdef, nodedef)
+
+ for k, v in pairs(redefinition) do
+ rawset(itemdef, k, v)
+ end
+ core.register_item_raw(itemdef)
+end
+