bug#8188: 24.0.50; incorrect column width in *Completions* buffer

[martin rudalics]

> emacs -q
> (split-window-horizontally 30)
> M-x o

C-x o presumably.

> C-h f [TAB]
>
> Result: The second column is obscured, only the first is visible.
>
> [SPC] [DEL] [TAB]
>
> Now the columns are calculated correctly.
>
> The reasons is that `window' in `completion--insert-strings' is set to nil 
unless a *Completions* buffer is already displayed. (minibuffer.el, line 951).

The *Completions* buffer is now by default displayed in a window on the
bottom of a frame so this bug has been fixed.

Thanks for the report, martin