Able to confuse export dialog by pressing back during export operations

[legoktm]

Description

I was able to confuse the export dialog into various states that shouldn't be possible (maybe ref #1875) by going backwards and forwards.

Steps to Reproduce

Please specify your environment if that is necessary to reproduce the bug (if in doubt, include it).

1. Set up SDW 0.10.0-rc3
2. Plug in a veracrypt drive, do not unlock it
3. Begin an export, hit the screen where you have Back / Continue / Cancel buttons, if you don't see the "If this is a VeraCrypt drive, ..." hit Continue till that error shows up
4. Unlock the VeraCrypt drive
5. Press Continue (spinner starts), then hit Back, then go forwards again, etc. The closer you hit Continue and then immediately Back to the unlocking of the drive seems to help with messing it up.

Expected Behavior

Ideally there are consistent states you enter/exit and it's not possible to get in the middle of one. But maybe the back button should be disabled once the export is in progress?

Actual Behavior

Export failed with no other details/error

Export failed with an active continue spinner

After some intermediate errors, I made it to the export complete screen except the header still says working

Comments

I was only able to get it to do something weird like a third of the time. I'm not really inclined to treat this as a 0.10.0 release blocker, I think we can expect users aren't frantically clicking back and continue during an export and keep it in the backlog to address later.