File openssh-7.7p1-X_forward_with_disabled_ipv6.patch of Package openssh.12800

# HG changeset patch
# Parent  44592f09f090e74432f608084069d30d808fda69
Do not throw away already open sockets for X11 forwarding if another socket
family is not available for bind()

diff --git a/openssh-7.7p1/channels.c b/openssh-7.7p1/channels.c
--- openssh-7.7p1/channels.c
+++ openssh-7.7p1/channels.c
@@ -4421,16 +4421,23 @@ x11_create_display_inet(struct ssh *ssh,
 			if (ai->ai_family == AF_INET6)
 				sock_set_v6only(sock);
 			if (x11_use_localhost)
 				set_reuseaddr(sock);
 			if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
 				debug2("%s: bind port %d: %.100s", __func__,
 				    port, strerror(errno));
 				close(sock);
+				/* do not remove successfully opened sockets if
+				 * the request failed because the protocol
+				 * IPv4/6 is not available (e.g. IPv6 may be
+				 * disabled while being supported)
+				 */
+				if (EADDRNOTAVAIL == errno)
+    					continue;
 				for (n = 0; n < num_socks; n++)
 					close(socks[n]);
 				num_socks = 0;
 				break;
 			}
 			socks[num_socks++] = sock;
 			if (num_socks == NUM_SOCKS)
 				break;