> 0. emacs -Q
> 1. M-x TAB
> 2. move point to the beginning of the *Completions* buffer
> 3. type S-TAB (<backtab>)
>
> Debugger entered--Lisp error: (args-out-of-range 0 0)
>   get-text-property(0 mouse-face)
>   next-completion(-1)
>   previous-completion(1)
>   funcall-interactively(previous-completion 1)
>   command-execute(previous-completion)
>   completing-read-default("M-x " ...)
>   read-extended-command()
>   command-execute(execute-extended-command)
>
>

-- 
	Philip Kaludercic