Assuming the user has a collab-enabled project, has done his first publish (this is not necessary, however) and there are some files with changes waiting to be published.

1. Manipulate an asset (rename, recase, edit, create all work) and publish.
2. Cancel (note that this obviously works better with a larger file as the window to cancel does not require feline-like reflexes)

Observed results: Note that the Collab window will display two issues:
a) It will display the error "Cannot submit change to server" (ALREADY logged: https://fogbugz.unity3d.com/f/cases/881196/ - Closing Duplicate in favor of this one)
b) It will ask you to Publish again but will display "0 changes"

Expected Result: The message should be "Operation Cancelled" and there should be changes displayed on the Collab window.