>I suppose that would be a frame with a minibuffer and a root window -
>correct?  Currently, we have no way to fix the size of the minibuffer
>window on such frames but we can easily provide a new frame parameter
>to do that.
>
>But why can't you just use two frames instead - one for the root and
>another for the minibuffer window?  A minibuffer-only frame has fixed
>size.  Even if we will change that in the future, there must be a way
>to inhibit that it resizes automatically.
I do not test the second method,  my concern is :
two frames method seem to need deal with some focus edge case. which may not good deal with.