assert NOARG/NONEG behavior of parse-options callbacks

diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index 88b86c8d9f5a0ea9c49b42e891082203b80a977f..eb74774cbc9d6bd6acf1b7fe2f31b8e80e461a12 100644 (file)
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -132,6 +132,8 @@ static const char * const builtin_checkout_index_usage[] = {
 static int option_parse_stage(const struct option *opt,
                              const char *arg, int unset)
 {
+       BUG_ON_OPT_NEG(unset);
+
        if (!strcmp(arg, "all")) {
                to_tempfile = 1;
                checkout_stage = CHECKOUT_ALL;