Handle Xauth in ssh/rc.

dotfiles/ssh/rc

@@ -13,3 +13,15 @@ fi
 if test \! -S "${REMOTE_LINK}" -a -S "${SSH_AUTH_SOCK}" ; then
   ln -sf "${SSH_AUTH_SOCK}" "${REMOTE_LINK}"
 fi
+
+# Handle X forwarding, per sshd(8)
+if read proto cookie && [ -n "$DISPLAY" ]; then
+  if [ `echo $DISPLAY | cut -c1-10` = 'localhost:' ]; then
+    # X11UseLocalhost=yes
+    echo add unix:`echo $DISPLAY |
+      cut -c11-` $proto $cookie
+  else
+    # X11UseLocalhost=no
+    echo add $DISPLAY $proto $cookie
+  fi | xauth -q -
+fi