1#!/bin/sh
2: ${GIT_DIR=.git}
3old=$(git-rev-parse HEAD)
4new=
5force=
6branch=
7while [ "$#" != "0" ]; do
8 arg="$1"
9 shift
10 case "$arg" in
11 "-f")
12 force=1
13 ;;
14 *)
15 rev=$(git-rev-parse "$arg")
16 if [ -z "$rev" ]; then
17 echo "unknown flag $arg"
18 exit 1
19 fi
20 if [ "$new" ]; then
21 echo "Multiple revisions?"
22 exit 1
23 fi
24 new="$rev"
25 if [ -f "$GIT_DIR/revs/heads/$arg" ]; then
26 branch="$arg"
27 fi
28 ;;
29 esac
30 i=$(($i+1))
31done
32[ -z "$new" ] && new=$old
33
34if [ "$force" ]
35then
36 git-read-tree --reset $new &&
37 git-checkout-cache -q -f -u -a
38else
39 git-read-tree -m -u $old $new
40fi && [ "$branch" ] && ln -sf "refs/heads/$branch" "$GIT_DIR/HEAD"