Scenario
Adding Fix version to a Bug / Story.
- If the Fix version field is empty I want the added version copied to the Bug's / Story's Sub-task.
- If the Fix version contains at least one version already, I want a new Sub-task to be created inheriting the added version (one for each version if several were added).
- I don't want to take time (say changes to the field the last week or between dates x and y) or whether the field was empty or not at some earlier point in time into consideration, just whether the field was or was not empty before the change triggering the rule.
My rule
When triggered (value added to Fix version field) and checked (for Bug / Story)
If fixversion changed from empty
For Sub-tasks
If status != done
Copy Fix version from trigger issue
Else
For each smart value (reading the added Fix version(s) from the changelog)
Create new Sub-task

Problem
The rule never enters the Else branch even if the Fix version Field is in fact empty when I add a version, it always enters the If branch.
I've tried using the Was operator as well ("fixversion was empty") but that doesn't work either but as far as I can tell that's to be expected when using Was, as Was looks at the entire history of the field. Is that true for Change as well? I e if the field at one point in history was empty (which is almost always the case in my scenario) the rule will never enter the Else branch? If so, how do I set up the rule to accommodate my scenario?
Results with an empty Fix version field when adding a version

Result with a version already in the Fix version field when adding a new version
