Scheduled transitions deleted after new revision is created

Problem/Motivation

Client reports scheduled transitions are deleted on certain workflows.

Steps to reproduce

- Create a node and publish it, add a transition somewhere in the future to state archived (lets say 5 days)
- Add a second transition somewhere sooner (lets say 3 days) to publish it.
- Edit the node and save as draft.
- The second transitions is gone!

Proposed resolution

Is this intended behaviour or have we found a bug?

Remaining tasks

User interface changes

API changes

Data model changes