vici: Catch Python GeneratorExit to properly cancel streamed event iteration

src/libcharon/plugins/vici/README.md

@@ -909,6 +909,11 @@ event:
 		for key in conn:
 			print key
 
+Please note that if the returned generator is not iterated completely, it must
+be closed using _close()_. This is implicitly done when breaking from a loop,
+but an explicit call may be required when directly iterating the generator with
+_next()_.
+
 ## Sorting in dictionaries ##
 
 In VICI, in some message trees the order of objects in dictionary matters. In

src/libcharon/plugins/vici/python/vici/session.py

@@ -281,10 +281,16 @@ class SessionHandler(object):
         # issue command, and read any event messages
         packet = Packet.request(command, message)
         self.transport.send(packet)
+        exited = False
         while True:
             response = Packet.parse(self.transport.receive())
             if response.response_type == Packet.EVENT:
-                yield Message.deserialize(response.payload)
+                if not exited:
+                    try:
+                        yield Message.deserialize(response.payload)
+                    except GeneratorExit:
+                        exited = True
+                        pass
             else:
                 break