giving_back = "bucket:bucket_empty" in register_full_bucket

CHANGELOG

@@ -7,6 +7,8 @@ Added settings:
 	
 Some code cleanup
 
+giving_back = "bucket:bucket_empty" in register_full_bucket as fallback
+
 --------------------------------------------------
 Ver. 4.1 [20.12.2020]
 

init.lua

@@ -152,10 +152,15 @@ end
 --    force_renew = (optional) bool. Force the liquid source to renew if it has a
 --                  source neighbour, even if defined as 'liquid_renewable = false'.
 --                  Needed to avoid creating holes in sloping rivers.
+--    giving_back = (NEW) defines the bucket to return
 -- This function can be called from any mod (that depends on bucket).
 
 local function register_full_bucket(source, flowing, itemname, inventory_image, name,
 		groups, force_renew, giving_back)
+	-- for compatibility - if not defined, then default empty bucket is used
+	if giving_back == nil then
+		giving_back = "bucket:bucket_empty"
+	end
 	minetest.register_craftitem(itemname, {
 		description = name,
 		inventory_image = inventory_image,