Greetings,

I found that when saving a file with a UTF-8 name, if the last character in
the file name is still underlined when "OK" is clicked, that last character
does not become a part of the filename.  I've tried this with a few apps
and the problem reoccurs, so I assume it is a GTK issue.

This is an unexpected behavior, hitting the "Enter" key at the same time
the last letter is committed as expected.  Clicking the "OK" should work
the same as hitting "Enter".  So, anytime an "OK" button is hit any
tentatively matched characters in the buffer should be committed.  Perhaps
this should the case when any button is hit if an "OK" button is not unique
from others.