add reflog entries for HEAD when detached

diff --git a/git-checkout.sh b/git-checkout.sh
index 8500f51ea27054d328be6e7e53c9f14d0d9c1979..ac378cdb1e7365758bb9309b92a6def77e593ef0 100755 (executable)
--- a/git-checkout.sh
+++ b/git-checkout.sh
@@ -259,8 +259,9 @@ if [ "$?" -eq 0 ]; then
                #       git update-ref --detach HEAD $new
                # or something like that...
                #
-               echo "$detached" >"$GIT_DIR/HEAD.new" &&
-               mv "$GIT_DIR/HEAD.new" "$GIT_DIR/HEAD" ||
+               git-rev-parse HEAD >"$GIT_DIR/HEAD.new" &&
+               mv "$GIT_DIR/HEAD.new" "$GIT_DIR/HEAD" &&
+               git-update-ref -m "checkout: moving to $arg" HEAD "$detached" ||
                        die "Cannot detach HEAD"
                if test -n "$detach_warn"
                then