Adjusting elastalert/ruletypes.py so that the functions 'append' and …

…'append_middle' take into account the scenario whereby an event is None

elastalert/ruletypes.py

@@ -318,12 +318,14 @@ def append(self, event):
         This will also pop the oldest events and call onRemoved on them until the
         window size is less than timeframe. """
         self.data.add(event)
-        self.running_count += event[1]
+        if event and event[1]:
+            self.running_count += event[1]
 
         while self.duration() >= self.timeframe:
             oldest = self.data[0]
             self.data.remove(oldest)
-            self.running_count -= oldest[1]
+            if oldest and oldest[1]:
+                self.running_count -= oldest[1]
             self.onRemoved and self.onRemoved(oldest)
 
     def duration(self):
@@ -363,7 +365,8 @@ def append_middle(self, event):
         # Append left if ts is earlier than first event
         if self.get_ts(self.data[0]) > ts:
             self.data.appendleft(event)
-            self.running_count += event[1]
+            if event and event[1]:
+                self.running_count += event[1]
             return
 
         # Rotate window until we can insert event
@@ -374,7 +377,8 @@ def append_middle(self, event):
                 # This should never happen
                 return
         self.data.append(event)
-        self.running_count += event[1]
+        if event and event[1]:
+            self.running_count += event[1]
         self.data.rotate(-rotation)