socket-util: fix getpeergroups() assert(fd) (#8080)

Don't assert on zero-value fds.

Fixes #8075.

diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index 2c70cade14dceaacde7fcc18b9a6159467429063..bd3cf6f86982e413f35bb572f5598775f4de0ad4 100644 (file)
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -1008,7 +1008,7 @@ int getpeergroups(int fd, gid_t **ret) {
         socklen_t n = sizeof(gid_t) * 64;
         _cleanup_free_ gid_t *d = NULL;
 
-        assert(fd);
+        assert(fd >= 0);
         assert(ret);
 
         for (;;) {