check for protection before allowing to write on the sign

init.lua

@@ -110,6 +110,10 @@ arrow_signs.savetext = function(pos, formname, fields, sender)
 			minetest.chat_send_player(sender:get_player_name(), "error: you don't have permission to edit the sign. you need the interact priv")
 		return
 		end
+		if minetest.is_protected(pos, sender:get_player_name()) then
+			minetest.record_protection_violation(pos, sender:get_player_name())
+			return
+		end
 		local meta = minetest.get_meta(pos)
 		fields.text = fields.text or ""
 		minetest.log("action", (sender:get_player_name() or "").." wrote \""..fields.text..