Subject: bug#18716: Patch for this bug

From: Drew Adams <[email-masked]>
Date: Wed, 9 Nov 2016 14:52:51 -0800 (PST)

> I double-checked, and the code I changed, dired-mark-unmarked-files, is
> only called by dired-omit. However, it can also be called interactively,
> so I have certainly changed the interactive behavior.

It can also be called from 3rd-party code.

(I don't understand the problem you are trying to solve, so I won't try
to comment further about the proposed solution.)