Merge pull request #2521 from sa2ajj/more-coverity-fixes

fix CID 1382001: Attribute/item access or function call before check for None or undefined

master/buildbot/www/ws.py

@@ -79,7 +79,7 @@ def cmd_startConsuming(self, path, _id):
             return
 
         # if it's already subscribed, don't leak a subscription
-        if path in self.qrefs:
+        if self.qrefs is not None and path in self.qrefs:
             yield self.ack(_id=_id)
             return
 
@@ -93,8 +93,10 @@ def callback(key, message):
         if self.qrefs is None or path in self.qrefs:
             qref.stopConsuming()
 
-        self.qrefs[path] = qref
-        self.ack(_id=_id)
+        # only store and ack if we were not disconnected in between
+        if self.qrefs is not None:
+            self.qrefs[path] = qref
+            self.ack(_id=_id)
 
     @defer.inlineCallbacks
     def cmd_stopConsuming(self, path, _id):