Index: src/network_driver.c
===================================================================
RCS file: /data/cvs/libxen/src/network_driver.c,v
retrieving revision 1.28
diff -u -r1.28 network_driver.c
--- src/network_driver.c	29 May 2009 14:18:57 -0000	1.28
+++ src/network_driver.c	3 Jun 2009 13:25:23 -0000
@@ -1353,6 +1353,12 @@
         goto cleanup;
     }
 
+    if (!network->persistent) {
+        networkReportError(net->conn, NULL, net, VIR_ERR_INTERNAL_ERROR,
+                         "%s", _("cannot set autostart for transient network"));
+        goto cleanup;
+    }
+
     autostart = (autostart != 0);
 
     if (network->autostart != autostart) {