Annoying shell *completions* buffer

[Francis Moreau]

Hello,

I'm using M-x shell, and would like to hide the *completions* buffer
automatically when the <TAB> key did a sole completion.

I know that I can type to <SPACE> to make the buffer disapears, but I
really find this behaviour, hmm, not logical.

Acutally <SPACE> seems broken: a) I can't let <TAB> do a full
completion otherwise <SPACE> doesn't flush anymore; b) if I do <TAB>
then partially type the filename then press again <TAB> then <SPACE>
doesn't flush anymore.

I just need to tell to emacs: if you find only one completion then the
completion buffer becomes useless. So restore the window configuration
how it was before the completion buffer pop up after completing.

Thanks