Something odd is going on here. Your cover letter and PATCH 4 arrived here with
Content-Type: text/plain; charset=UTF-8
Good.
PATCH 2:
Content-Type: text/plain; charset="US-ASCII"; x-default=true
PATCH 1 and 3:
Content-Type: text/plain; charset=N
git-am chokes on that:
error: cannot convert from N to UTF-8
