ZLE redraw bug

["Matt Wozniski" <godlygeek@gmail.com>]

OK, this has been bugging me for a while, and was still an issue with
4.3.5 dev 4, so I finally sat down to try to get a manageable test
case for it.  Hopefully this is small enough.  :)

zsh -f
mastermind% autoload -U compinit; compinit
mastermind% zstyle ':completion:*' completer _approximate
mastermind% zstyle ':completion:*' menu select=2
mastermind% path=()
mastermind% function manpath { }
mastermind% mna<TAB> ("mna" changes to "enable" from menu selection)
enable     mailpath   manpath    manpath    nameddirs  _nautilus  unalias
mna

note that manpath appears twice in the listing - I think that's what's
screwing things up internally...  because if I now do <CTRL-u> to kill
the line, I get:

<-snip->
mastermind% enable
enable     m

mna
<-snap>

with the cursor after the 'm' on the second line.

If I then do "unfunction manpath" and try the completion/line kill
again, things work properly.

Can anyone help me figure out what might be going wrong?  I don't even
know where to begin debugging ZLE, heh.

Thanks!
~Matt