Node can't be added with the same role after discard node addition

[Andrey Sledzinskiy]

Bug is reproduced on fuel-4.1-91-2014-02-05_01-17-30.iso

Steps:
1. Create new environment with all default values
2. Open Nodes tab
3. Click 'Add Nodes'
4. Assign Compute role to any Node
5. Click Apply Changes – changes are saved and page with added nodes is present
6. Click 'discard addition' for added Node
7. Click 'Add Nodes' again

First Bug:
Actual - 'Compute' checkbox is selected (without tick) - see attach checboxdiscardbug.png.
Expected – all checkboxes aren't selected

8. Assign Compute role to this Node again
Actual – 'apply changes' button is not active and it becomes active only if you unselect Compute checkbox and select Node (attach DiscardBug.png)
Expected - 'apply changes' button is active and node can be added with 'Compute' role again

[Andrey Sledzinskiy (asledzinskiy)]

attachment for checkbox bug

[Alexandra Morozova (astepanchuk)]

The issue seems to be with python PUT /api/nodes/:id handler - making a PUT-request to the url specified with the next body {
cluster: null
pending_addition: false
pending_roles: []
}
I gain the next response - {
status: "discover"
 ...
error_type
 null

pending_addition
 false
...
cluster
 null

pending_deletion
 false

pending_roles
 ["compute", "cinder"]

...
}

But I expect to get "pending_roles" as an empty array.