Set a DBusError in all failing paths of bus_selinux_check()

Bug: dbus/dbus#198

bus/selinux.c

@@ -423,13 +423,16 @@ bus_selinux_check (BusSELinuxID        *sender_sid,
     switch (errno)
       {
       case EACCES:
-        _dbus_verbose ("SELinux denying due to security policy.\n");
+        dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
+                        "SELinux denying due to security policy.");
         return FALSE;
       case EINVAL:
-        _dbus_verbose ("SELinux denying due to invalid security context.\n");
+        dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
+                        "SELinux denying due to invalid security context.");
         return FALSE;
       default:
-        _dbus_verbose ("SELinux denying due to: %s\n", _dbus_strerror (errno));
+        dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
+                        "SELinux denying due to: %s", _dbus_strerror (errno));
         return FALSE;
       }
     }

bus/services.c

@@ -445,20 +445,13 @@ bus_registry_acquire_service (BusRegistry      *registry,
   if (!bus_selinux_allows_acquire_service (connection, sid,
 					   _dbus_string_get_const_data (service_name), error))
     {
-
-      if (dbus_error_is_set (error) &&
-	  dbus_error_has_name (error, DBUS_ERROR_NO_MEMORY))
-	{
-	  goto out;
-	}
-
-      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
-                      "Connection \"%s\" is not allowed to own the service \"%s\" due "
-                      "to SELinux policy",
+      _dbus_verbose ( "Connection \"%s\" is not allowed to own the service \"%s\" due "
+                      "to SELinux policy: \"%s\"\n",
                       bus_connection_is_active (connection) ?
                       bus_connection_get_name (connection) :
                       "(inactive)",
-                      _dbus_string_get_const_data (service_name));
+                      _dbus_string_get_const_data (service_name),
+                      error->message);
       goto out;
     }