dired-sort-toggle-or-edit: don't wipe out window on invalid ls switch

[Dan Jacobson]

I am in dired.  I use a invalid ls option, e.g. -y, to C-u s.

Why do invalid ls options have to cause "catastrophic loss of the
content of one's window", when a little message in the minibuffer will
do?  If one's directory becomes suddenly less than a pixel, the user
will feel disconcerted.

Maybe don't change the content of the screen until you have results
worth changing to.

At this point typing C-x d RET or C-x d . RET won't make things better.

BTW, if I was also using a wildcard, it also says insert-directory:
Reading directory: no such file or directory,
/home/jidanni/kejia/guangfu7/jidanni/7-06.*
-- 
http://jidanni.org/ Taiwan(04)25854780