[FIX] base_user_role: ensure that the user's groups are updated when its last role line is removed

base_user_role/models/role.py

@@ -52,7 +52,7 @@ class ResUsersRole(models.Model):
     def unlink(self):
         users = self.mapped('user_ids')
         res = super(ResUsersRole, self).unlink()
-        users.set_groups_from_roles()
+        users.set_groups_from_roles(force=True)
         return res
 
     @api.multi
@@ -99,5 +99,5 @@ class ResUsersRoleLine(models.Model):
     def unlink(self):
         users = self.mapped('user_id')
         res = super(ResUsersRoleLine, self).unlink()
-        users.set_groups_from_roles()
+        users.set_groups_from_roles(force=True)
         return res

base_user_role/models/user.py

@@ -32,12 +32,13 @@ class ResUsers(models.Model):
         return res
 
     @api.multi
-    def set_groups_from_roles(self):
+    def set_groups_from_roles(self, force=False):
         """Set (replace) the groups following the roles defined on users.
-        If no role is defined on the user, its groups are let untouched.
+        If no role is defined on the user, its groups are let untouched unless
+        the `force` parameter is `True`.
         """
         for user in self:
-            if not user.role_line_ids:
+            if not user.role_line_ids and not force:
                 continue
             group_ids = []
             role_lines = user.role_line_ids.filtered(