unreading a command key sequence

[Lennart Borgman (gmail)]

I just had a problem with unreading a command key sequence that lead to 
that Emacs looped. Looking into it I found that it is a bit non-trivial 
to unread a command key sequence. I am not sure I have got every thing 
correct but this is what I am using now

  ;; Unread the last command
  (setq last-command-char nil) ;; For viper
  (setq unread-command-events
        (listify-key-sequence (this-command-keys-vector)))

The missing bit that lead to the looping was setting last-command-char 
to nil.

Maybe something like this could be included in the manual in
(info "(elisp) Event Input Misc")?