Comment # 28 on bug 979265 from Wolfgang Bauer

I tried it, but there's a regression:
It doesn't accept kde4-krusader.desktop any more, though that did work before
(xdg-open did start krusader if mimeapps.list contained kde4-krusader.desktop,
without the semicolon at least).

krusader.desktop does work, but KDE's systemsettings writes
kde4-krusader.desktop because krusader.desktop is installed to
/usr/share/applications/kde4/ (that's correct behaviour AFAIK, and does still
work in a KDE session).

Other than that it does seem to work, it uses the first application in the list
if that exists, if not it tries the second one, and so on.

Another remark:
The second change in
xdg-mime-generic-do-not-return-more-than-one-default-2.patch doesn't make sense
to me, it doesn't have any effect IMHO.
The assignment to trader_result already does cut off everything after (and
including) the first semicolon (cut -d ';' -f 1).
As there can be multiple .desktop files in this case too, that "| cut -d ';' -f
1" (at the end of line 386 in the original file) should be removed I'd say.