This is a companion patch to previous 8763dbb (completion: fix PS1 display
during a merge on detached HEAD, 2009-05-16). While rebasing or running am
on a detached HEAD, the code failed to set $b (branch description) that
enables the whole status display business.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
d7107ca65f