Nodes are shared by all plans, but if different plans define different roles, the nodes that assigned to those roles will appear as "not assigned" in plans that don't recognise them.
Note: tested after applying the patches for bug 1644310 and bug 1643882.
Steps to Reproduce:
1. Upload a plan with custom roles
2. Assign nodes to these roles and check in the Nodes page that the assigned role is displayed on the nodes
3. Switch to another active plan
4. Look in the Nodes page again
Actual results:
The nodes appear as "not assigned". We could have a collision here if the same nodes are assigned to different roles in different plans.
Expected results:
The assigned role should be displayed even if such a role doesn't exist in the plan that is currently active.
This is confusing at the moment. For example I assigned a node to a custom role in a plan, but didn't deploy it. Later on I started working with another plan and wondered why I only had two nodes available for deployment in the Deployment Plan page, when there should have been three. Looking at the Nodes page, the 3 nodes are showing correctly, including one "Not assigned" (which is actually assigned to the custom-role) - it's not obvious why it's not available from the plan page or why it's not possible to assign/manage it. You have to remember which plan had that role associated to go unassign it.
related to bug 1640103