Add test to verify comparing with deleted version works. (#13398)
Add test to verify comparing with deleted version works. (#13398)

* Add test to verify comparing with deleted version works.

Fixes #12726

* Add comment

eviljeff/olympia,bqbn/addons-server,wagnerand/addons-server,bqbn/addons-server,mozilla/addons-server,wagnerand/addons-server,bqbn/addons-server,diox/olympia,mozilla/addons-server,mozilla/olympia,diox/olympia,eviljeff/olympia,eviljeff/olympia,diox/olympia,bqbn/addons-server,mozilla/olympia,mozilla/olympia,mozilla/addons-server,diox/olympia,eviljeff/olympia,wagnerand/addons-server,mozilla/olympia,mozilla/addons-server,wagnerand/addons-server