prevent potential undefined behaviour

1 files changed, 2 insertions, 0 deletions

diff --git a/simplebl.c b/simplebl.c
index 2890bd2..de80227 100644
--- a/simplebl.c
+++ b/simplebl.c
@@ -105,6 +105,8 @@ check_group(void)
 	glist_size = getgroups(0, NULL);
 	if (errno)
 		die("getgroups: %s\n", strerror(errno));
+	if (!glist_size)
+		die("getgroups: User has no supplementary groups\n");
 	glist = calloc(glist_size, sizeof(*glist));
 	if (!glist)
 		die("check_group: Out of memory\n");