Re: undo gone in dired buffers

[Francesco Potorti`]

>    It used to work in dired buffers.
>
>That seems incredible.  Deleting the whole text of a directory listing
>and reading it again is an operation that cannot preserve undo data.

Yet, this is easy to reproduce.  Invoke emacs 21 with -q, then

C-x d /tmp RET
M-! touch 00a RET
g --> Now yu should see a file named 00a
C-x C-q
undo --> Now you don't see the file 00a any more

it was useful when I updated a dired buffer with 'g' without looking at
it first, and wanted to look at its old status.  Very handy in some
situations.