This can be repaired to be structurally sound with addition of a bolt running vertically through the rail (a drill press is required) at the location of the crack. Be sure that the thickness of the bolt and therefore the hole, is not more than one third of the rail thickness. If the crack is long, (more than a foot) use two bolts. Inject glue into the crack with a hypodermic needle before tightening the bolt. Now you may take a nap.