From 428f9bc117ae65b8d7db8b84f8b0f5cac8652fb1 Mon Sep 17 00:00:00 2001
From: William Pitcock <nenolod@dereferenced.org>
Date: Wed, 2 Mar 2016 15:56:49 -0600
Subject: [PATCH] client: handle UID rollover.  ircd-ratbox r28917

---
 ircd/client.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/ircd/client.c b/ircd/client.c
index 025b4b1a..963c89b9 100644
--- a/ircd/client.c
+++ b/ircd/client.c
@@ -1860,19 +1860,21 @@ init_uid(void)
 char *
 generate_uid(void)
 {
+	static int flipped = 0;
 	int i;
 
+uid_restart:
 	for(i = 8; i > 3; i--)
 	{
 		if(current_uid[i] == 'Z')
 		{
 			current_uid[i] = '0';
-			return current_uid;
+			goto out;
 		}
 		else if(current_uid[i] != '9')
 		{
 			current_uid[i]++;
-			return current_uid;
+			goto out;
 		}
 		else
 			current_uid[i] = 'A';
@@ -1882,11 +1884,18 @@ generate_uid(void)
 	if(current_uid[3] == 'Z')
 	{
 		current_uid[i] = 'A';
-		s_assert(0);
+		flipped = 1;
 	}
 	else
 		current_uid[i]++;
-
+out:
+	/* if this happens..well, i'm not sure what to say, but lets handle it correctly */
+	if(rb_unlikely(flipped))
+	{
+		/* this slows down uid generation a bit... */
+		if(find_id(current_uid) != NULL)
+			goto uid_restart;
+	}
 	return current_uid;
 }