bug#33458: 27.0.50; dired loses position when reverted from outside place

[martin rudalics]

> Maybe marker-position should allow to call a function?
> For example, like 'isearch-push-state-function' remembers
> an additional state as a lambda, and when an old state is
> restored, a pop-fun lambda is called.  The function that
> restores the buffer in the window could be the same.

The problem we face here is almost exclusively restricted to reverting
buffers and 'marker-position' is too heavily used as to be affected by
that.  Now, if we talk about dired buffers only, they have a very
helpful restriction that invariably permeates all file systems: The
file names in a directory must be unique.  So if a marker is on the
line of a file name it can quite easily return to that name after
reversal (provided the file still exists).  A similar argument should
hold for non-file visiting buffers like Buffer List buffers.  Finally,
in quite a number of cases 'auto-revert-tail-mode' should take care of
markers in the unchanged initial part of a file.  Do we have many
other auto-reverted buffers?

martin