commit aaf30454802855d439f3d4d1a12fd6b905621029
Author: Svante Signell <svante.signell@gmail.com>
Date:   Tue Aug 30 23:06:31 2016 +0200

    hurd: Fix adjtime call with OLDDELTA == NULL
    
    * sysdeps/mach/hurd/adjtime.c (__adjtime): When OLDDELTA is NULL, make
    it point to a dumb buffer for RPC to fill it.

diff --git a/sysdeps/mach/hurd/adjtime.c b/sysdeps/mach/hurd/adjtime.c
index d65b95b..7cfdd53 100644
--- a/sysdeps/mach/hurd/adjtime.c
+++ b/sysdeps/mach/hurd/adjtime.c
@@ -28,11 +28,15 @@ __adjtime (const struct timeval *delta, struct timeval *olddelta)
 {
   error_t err;
   mach_port_t hostpriv;
+  struct timeval dummy;
 
   err = __get_privileged_ports (&hostpriv, NULL);
   if (err)
     return __hurd_fail (EPERM);
 
+  if (olddelta == NULL)
+    olddelta = &dummy;
+
   err = __host_adjust_time (hostpriv,
 			    /* `time_value_t' and `struct timeval' are in
                                fact identical with the names changed.  */