Sometimes when administering permissions, I want to have multiple roles displayed for comparison perposes even though I only want to edit a single role. It is easy to accidentally make changes on the permissions page which can cause an administrator to not be able to administer any more. I know because I just did it, and it required going to user 1 to fix it. Given the hundreds of check boxes on the page, it would be better if Drupal provided a way to lock a role from changes when updating permissions.
Example:
Goal: Set permissions for Medium Permission User. Use Low Permission User and Administrator as reference.
Current steps:
1. Go to https://sfmta.prod.acquia-sites.com/admin/people/permissions
2. Filter to show roles Low Permission User, Medium Permission User, Administrator.
3. Display all modules.
4. Click Filter Permissions.
5. Check permissions to be used by Medium Permission User, using Low Permission User and Administrator as reference.
6. As the page is very long, accidentally click permissions in Low Permission User and Administrator. The permissions get set to the wrong values.
7. Save permissions.
8. Suddenly not be able to access /admin
New feature steps:
1. Go to https://sfmta.prod.acquia-sites.com/admin/people/permissions
2. Filter to show roles Low Permission User, Medium Permission User, Administrator.
3. Display all modules.
4. Click Filter Permissions.
5. Click Lock symbol at the top of the Low Permission User and Administrator columns.
6. Check permission to be used by Medium Permission User, using Low Permission User and Administrator as reference.
7. As the page is very long, accidentally click permissions in Low Permission User and Administrator. As the check boxes are locked, nothing happens.
8. Save permissions.
9. No harm done.