Comment 1 for bug 1646212

The issue here is that a user has taken an overt action (unshelve) against a VM that will cause its state to change from STOPPED while there is still a pending STOPPED event in the queue. In this particular case unshelve eventually calls driver.spawn which will attempt to change the state of the VM.

I believe that the proper fix for this is to have the driver.spawn code first clear all pending STOP event from the queue before it attempts to spawn the instance. This ensures that any old events aren't accidentally processed after we have already taken an overt action to change the state.