[PATCH] param: return error when assigning empty string

[Ahmad Fatoum <a.fatoum@barebox.org>]

The fallback path that allows specifying enum values by index returns an
error if *endp != '\0' to account for invalid values like my.enum.param=1z.

This fails to account for the corner case of the empty string which
would also have *endp == '\0; with idx being the default 0.

Check for that explicitly and return an error.

Signed-off-by: Ahmad Fatoum <a.fatoum@barebox.org>
---
 lib/parameter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/parameter.c b/lib/parameter.c
index f4e62cc1ae87..e98739725fe2 100644
--- a/lib/parameter.c
+++ b/lib/parameter.c
@@ -593,7 +593,7 @@ static int param_enum_set(struct bobject *bobj, struct param_d *p,
 		char *endp;
 		unsigned long idx = simple_strtoul(val, &endp, 0);
 
-		if (*endp || idx >= pe->num_names || !pe->names[idx])
+		if (*endp || endp == val || idx >= pe->num_names || !pe->names[idx])
 			return -EINVAL;
 
 		pr_warn("setting %s.%s by index is not stable, use \"%s\" instead\n",
-- 
2.47.3