difftool --no-index: error out on --dir-diff (and don't crash)

diff --git a/git-submodule.sh b/git-submodule.sh
index b5f2beee60ab59a04b5b236da8df39403009db1b..514ede259660d387fd392b950facc706f7c4d5e7 100755 (executable)
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -5,7 +5,8 @@
 # Copyright (c) 2007 Lars Hjemli
 
 dashless=$(basename "$0" | sed -e 's/-/ /')
-USAGE="[--quiet] add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--] <repository> [<path>]
+USAGE="[--quiet] [--cached]
+   or: $dashless [--quiet] add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--] <repository> [<path>]
    or: $dashless [--quiet] status [--cached] [--recursive] [--] [<path>...]
    or: $dashless [--quiet] init [--] [<path>...]
    or: $dashless [--quiet] deinit [-f|--force] (--all| [--] <path>...)