After failed patch application, you can manually apply the patch
(this includes resolving the conflicted merge after git-am falls
back to 3-way merge) and run git-update-index on necessary paths
to prepare the index file in a shape a successful patch
application should have produced.  Then re-running git-am --resolved
would record the resulting index file along with the commit log
information taken from the patch e-mail.

Signed-off-by: Junio C Hamano <junkio@cox.net>