Add a check that min and max revisions aren't equal in progression task. (#1265)
Add a check that min and max revisions aren't equal in progression task. (#1265)

* Add a check that min and max revisions aren't equal in progression task.

* Explicitly bail out if we would reach and infinite loop.

* Fix nits

google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz