branch=
reference=
cached=
+recursive=
+init=
files=
nofetch=
update=
test $# = 0 || shift
elif test -z "$1" -o "$1" = "HEAD"
then
- return
+ # before the first commit: compare with an empty tree
+ head=$(git hash-object -w -t tree --stdin </dev/null)
+ test -z "$1" || shift
else
head="HEAD"
fi