[All Versions] [base_user_role] Manual group assignment persistent when adding user to group

[much-filipe-colaco]

Module

base_user_role

Describe the bug

• When a user has user roles defined, it is not possible to manually set groups on users as the module will override the groups list with the ones coming from the roles
• This is achieved by res.users's create() and write() calling set_groups_from_roles()
• Issue: There is no check on the res.groups's create() and write(), meaning if se set a user on the group's user list the group is actually assigned

To Reproduce

Affected versions: All versions

Steps to reproduce the behavior:

1. Go to a user without roles, manually assign a group: group remains assigned
2. Go to a user with roles, manually assign a group: group does not remain assigned
3. Go to a group, add a user without roles to the list of users: group remains assigned
4. Go to a group, add a user with roles to the list of users: group remains assigned (issue)

Expected behavior
On step 4, the group should not remain assigned, mimicking step 2.