connection: Make sure capabilities are refreshed as needed

src/virtManager/connection.py

@@ -118,6 +118,9 @@ class vmmConnection(gobject.GObject):
         self.state = self.STATE_DISCONNECTED
         self.vmm = None
 
+        self._caps = None
+        self._caps_xml = None
+
         self.network_capable = None
         self.storage_capable = None
         self.interface_capable = None
@@ -258,8 +261,22 @@ class vmmConnection(gobject.GObject):
     def get_uri(self):
         return self.uri
 
+    def _invalidate_caps(self):
+        self._caps_xml = None
+        self._caps = None
+
+    def _check_caps(self):
+        self._caps_xml = self.vmm.getCapabilities()
+        self._caps = virtinst.CapabilitiesParser.parse(self._caps_xml)
+
     def get_capabilities(self):
-        return virtinst.CapabilitiesParser.parse(self.vmm.getCapabilities())
+        # Make sure we aren't returning None
+        caps = None
+        while caps == None:
+            self._check_caps()
+            caps = self._caps
+
+        return self._caps
 
     def get_max_vcpus(self, _type=None):
         return virtinst.util.get_max_vcpus(self.vmm, _type)
@@ -1334,6 +1351,7 @@ class vmmConnection(gobject.GObject):
             return
 
         self.hostinfo = self.vmm.getInfo()
+        self._invalidate_caps()
 
         # Poll for new virtual network objects
         (startNets, stopNets, newNets,