Query state/status of cancelled query is reported as FINISHED/OK

Problem Statement:
The query status should be "CANCELLED" if the query is cancelled. However, cancelling it through the shell does not do that. The query status still appear as ok:

Query Type: QUERY
Query State: FINISHED
Query Status: OK

This does not happen consistently and we don't know if there are any other conditions that result in this behavior. There is no known workaround.

Impact
It is impossible to tell, from the query profile status, whether the query finished successfully or not. It makes diagnosing query issue a lot harder.
Impala clients have to handle more different states, compared to the scenario where the final states of the query are more consistent.