Conflict when applying a parent link to an issue that has an Epic link set

Issue Summary

If you try to set a Parent Link to an issue that has an Epic Link set, the change will not be saved due to a conflict within the hierarchy.

Steps to Reproduce

• Create two issue types and add them to two new levels above the Epic in the hierarchy
  • On this example, I created Part and Initiative
    
• Create en Epic issue
• Create a Part issue, and add an Epic Link to the previously created Epic
• Create an initiative issue
• Try to update the Parent Link inside the Part issue, pointing to the Initiative created in the previous step

Expected Results

The update will persist. The Initiative will be kept as the parent of the Part issue.

Actual Results

The change does not persist. Only the Epic is kept as the parent.
Parent link conflict.mp4

Workaround

Remove the Epic Link before adding a parent link in the issue.

Considerations

There are some scenarios that could/should be considered:

• Since the Epic is beneath those issue types in the hierarchy, maybe it shouldn't be possible to set it as a parent of those issue types trough the Epic link field
• The error should not occur silently
  • There could be a message stating that the issue has a parent set already