+ if test -z "$patch_format" &&
+ test -n "$l1" &&
+ test -n "$l2" &&
+ test -n "$l3"
+ then
+ # This begins with three non-empty lines. Is this a
+ # piece of e-mail a-la RFC2822? Grab all the headers,
+ # discarding the indented remainder of folded lines,
+ # and see if it looks like that they all begin with the
+ # header field names...
+ sed -n -e '/^$/q' -e '/^[ ]/d' -e p "$1" |
+ egrep -v '^[A-Za-z]+(-[A-Za-z]+)*:' >/dev/null ||
+ patch_format=mbox
+ fi