From 2be7a39beaa4e640153f5a5919db93fff2a11700 Mon Sep 17 00:00:00 2001
From: Luke Dennis <luke.j.dennis@gmail.com>
Date: Thu, 9 Jun 2022 12:54:46 +1000
Subject: [PATCH] Add check for n_users to prevent segfault

When doinkd is started with 0 current users, `user` is uninitialised when
passed to `chk_maxuser()`. Adding this check prevents `user` being accessed
when unitialised.
---
 doinkd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doinkd.c b/doinkd.c
index 4a6f6d8..90e2517 100644
--- a/doinkd.c
+++ b/doinkd.c
@@ -651,7 +651,7 @@ void chk_maxuser(user, n_users)
    int grpcnt = 0;
    int tgrpcnt = 0;
    
-   if (user->mgroup != 0) {
+   if (n_users && user->mgroup != 0) {
      for (i = 0; i < n_users; i++) {
 	   if ( (*pusers[i]).uid == user->uid)
           who = i;