Re: Can't interrupt directory_files_internal run fromtimer-event-handler

[Richard M. Stallman]

    For that reason, I think we should either document throw-on-input (and
    keep its name), or [better] change while-no-input to return `quit' for
    C-g, `input-pending-p' for input, and value of BODY otherwise.

This won't achieve the goal of making it possible to distinguish all
the possible cases.  It just makes the confusion cases less likely.

However, if you write (list ...) around the intended body form,
then you can tell for certain whether the body form finished.
As for distinguishing between C-g and other input, I think a simple
change will make `while-no-input' return t when there's input.
I will install that soon.