--- unix/xserver/os/access.c	2012-02-24 15:32:16.683508316 +0100
+++ unix/xserver/os/access.c	2012-02-24 15:32:16.899508318 +0100
@@ -802,7 +802,9 @@
 
 	    /* 
 	     * ignore 'localhost' entries as they're not useful
-	     * on the other end of the wire
+	     * on the other end of the wire and because on hosts
+	     * with shared home dirs they'll result in conflic
+	     * entries in ~/.Xauthority
 	     */
 	    if (ifr->ifa_flags & IFF_LOOPBACK) 
 		    continue;
@@ -825,6 +827,14 @@
 	    else if (family == FamilyInternet6 && 
 	      IN6_IS_ADDR_LOOPBACK((struct in6_addr *)addr))
 		continue;
+
+            /* Ignore IPv6 link local addresses (fe80::/10), because
+             * they need a scope identifier, which we have no way
+             * of telling to the other end.
+             */
+            if (family == FamilyInternet6 &&
+              IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr))
+                continue;
 #endif
 	    XdmcpRegisterConnection(family, (char *)addr, len);
 #if defined(IPv6) && defined(AF_INET6)