Re: dired-do-shell-command mention dired-guess-shell-alist-user

[Richard Stallman]

    There were discussions about moving shell command guessing code from 
    dired-x.el to dired-aux.el (or in dired.el).  I think this should be done
    before the next release because it will eliminate an unfinished feature
    in dired.el which uses dired-view-command-alist and which partly started
    duplicating the functionality already present in dired-x.el.

    I could submit the patch to emacs-devel if Richard agrees.

Dave Love suggested using the code from gnus-dired.el and mailcap.el.
That code seems to be very clean, so I would like to use that.
However, that code currently depends on various other parts of Gnus;
it will be necessary to work on the code so as to eliminate
the extra dependencies.

Want to do that?

Some additional advice of his:

    However, mailcap.el still needs fixing, as I reported before.  It
    shouldn't override the system mailcap files by default -- otherwise it
    can fail the same way dired `v' does now.  It shouldn't fail due to
    the viewer not being available -- it should check it's executable
    before trying to use it.

I just deleted the code I had added to dired.el