Hello,

I think this patch is self-explanatory.  In order to get the ding you
have to "(setopt completion-auto-help 'visible)" and try to complete
something successfully.  I was doing 'M-x eshell-command-mo <TAB>' to
complete the symbol eshell-command-mode.

I'm not sure if that's actually the complete minimal setup, but I don't
think you guys have to bother reproducing it since it's pretty obvious
my patch is an improvement.