Deal with domain info going away (handle new error path introduced by

cset 6828). Believe Dan Smith is working up a more comprehensive patch.

Signed-off-by: Steven Hand <steven@xensource.com>

tools/python/xen/xend/XendDomainInfo.py

@@ -353,7 +353,12 @@ class XendDomainInfo:
     def update(self, info=None):
         """Update with  info from xc.domain_getinfo().
         """
-        self.info = info or dom_get(self.domid)
+        if info:
+            self.info = info
+        else:
+            di = dom_get(self.domid)
+            if not di:
+                return 
         self.memory = self.info['mem_kb'] / 1024
         self.ssidref = self.info['ssidref']