clef change in 1st ending

[David Zelinsky]

I have a repeated section that starts in tenor clef, then changes to
bass clef (before the repeat).  I want to show a tenor clef at the end
of the 1st ending, just before the repeat sign, as a reminder that the
repeat starts in that clef.  But when I put '\clef "tenor"' in the first
\alternative, the 2nd ending then also gets engraved in tenor clef,
which is not right.  Adding '\clef "bass" at the beginning of the 2nd
\alternative makes the tenor clef in the 1st ending disappear.

What is the correct way to deal with this situation?

(I'm sure I've seen a way to force a clef to be visible in situations
like this, but try as I might I can't find it.)

-David