#!/bin/sh
. git-sh-setup || die "Not a git archive"
+usage () {
+ die "usage: git checkout [-f] [-b <new_branch>] [<branch>] [<paths>...]"
+}
+
old=$(git-rev-parse HEAD)
new=
force=
"-f")
force=1
;;
+ --)
+ break
+ ;;
+ -*)
+ usage
+ ;;
*)
- rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null) ||
- die "I don't know any '$arg'."
- if [ -z "$rev" ]; then
- echo "unknown flag $arg"
- exit 1
- fi
- if [ "$new" ]; then
- echo "Multiple revisions?"
- exit 1
- fi
- new="$rev"
- if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
- branch="$arg"
+ if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
+ then
+ if [ -z "$rev" ]; then
+ echo "unknown flag $arg"
+ exit 1
+ fi
+ new="$rev"
+ if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+ branch="$arg"
+ fi
+ elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
+ then
+ # checking out selected paths from a tree-ish.
+ new="$rev"
+ branch=
+ else
+ new=
+ branch=
+ set x "$arg" "$@"
+ shift
fi
+ break
;;
esac
done
-[ -z "$new" ] && new=$old
+# The behaviour of the command with and without explicit path
+# parameters is quite different.
+#
+# Without paths, we are checking out everything in the work tree,
+# possibly switching branches. This is the traditional behaviour.
#
+# With paths, we are _never_ switching branch, but checking out
+# the named paths from either index (when no rev is given),
+# or the named tree-ish (when rev is given).
+
+if test "$#" -ge 1
+then
+ if test '' != "$newbranch$force"
+ then
+ die "updating paths and switching branches or forcing are incompatible."
+ fi
+ if test '' != "$new"
+ then
+ # from a specific tree-ish; note that this is for
+ # rescuing paths and is never meant to remove what
+ # is not in the named tree-ish.
+ git-ls-tree -r "$new" "$@" |
+ sed -ne 's/^\([0-7]*\) blob \(.*\)$/\1 \2/p' |
+ git-update-index --index-info || exit $?
+ fi
+ git-checkout-index -f -u -- "$@"
+ exit $?
+else
+ # Make sure we did not fall back on $arg^{tree} codepath
+ # since we are not checking out from an arbitrary tree-ish,
+ # but switching branches.
+ if test '' != "$new"
+ then
+ git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
+ die "Cannot switch branch to a non-commit."
+ fi
+fi
+
+[ -z "$new" ] && new=$old
+
# If we don't have an old branch that we're switching to,
# and we don't have a new branch name for the target we
# are switching to, then we'd better just be checking out
# what we already had
-#
+
[ -z "$branch$newbranch" ] &&
[ "$new" != "$old" ] &&
die "git checkout: you need to specify a new branch name"