After refactoring of some of the tag copying functions in
9aad89da, "other" tag fields (those not
shown in the UI, but intended to be preserved) were lost when saving a
file with modified tags. There was one instance in the refactoring where
arguments to et_file_tag_copy_other_into() should have been swapped, and
were not.

Thanks to Philippe Troin for the bug report and initial patch.

https://bugzilla.gnome.org/show_bug.cgi?id=795018