I've lost all my changes in the edited file because of the wrong
input arguments for window-in-direction.  Here's is what happened:
I forgot that the minibuffer was activated, and in the buffer
called the command windmove-display-down.  But it displayed
the text buffer in the minibuffer window.  Then I noticed this
and exited the minibuffer.  But exiting the minibuffer wiped off
the contents of the minibuffer window, i.e. cleared the text buffer
that was displayed in the minibuffer window.  This is because
currently windmove-display-in-direction doesn't send the arg
'nomini' to window-in-direction.  And it can't send this arg,
because currently window-in-direction ignores the value 'nomini',
and doesn't send its MINIBUF arg to walk-window-tree unchanged.

So here is a patch to avoid such accidents.  It sends MINIBUF arg
from window-in-direction to MINIBUF arg of walk-window-tree: