Take care of simple, exceptional cases before the meat of the "check
out by branch name" code begins. After this change, the function
vaguely follows the following pseudocode:
if (-B or -b)
create branch;
if (plain "git checkout" or "git checkout HEAD")
;
else if (--detach or checking out by non-branch commit name)
detach HEAD;
else if (checking out by branch name)
attach HEAD;
One nice side benefit is to make it possible to remove handling of
the --detach option from outside switch_branches.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>