Re: error when using keyboard-quit (^G)

[Richard Stallman]

      What happens is
    that the active cursor moves from the bottom half (window) to the top
    window, and the bottom window's location within the file gets lost.

What, concretely, does it mean to say that "the bottom window's
location within the file gets lost"?  What exactly happens to the cursor?
Does the cursor disappear?  Does the cursor move in the buffer?

Once you get to a situation where the problem happens, does to happen
reliably then?