I noticed that when you scroll through the history in the slime REPL, when you reach the end it doesn't clear the commandline, as bash and other shells do. I think this is rather inconvenient, so I patched it up. I made it so there's a blank space at the beginning, too, just because. No reason not to.
I added a customization setting under Repl, that defaults to NIL. When it's true, the history will wrap around when the end is reached and you keep going.
Chris Capel