Checking some stuff I have found that there is an old check for null in ComponentAttributesMap.put(...)
This check doesn't have sense, because null values are valid for hashmap, and in that sense the check is useless.
The fix is very simple, just remove the unnecessary check. I just comment the related code, to prevent other people to try to add it in the future.
The fix will be done on 2.0.x, 2.1.x and 2.2.x branches