User count / roles inconsistency if roles no longer exist but users still do

[anmari]

The count_users logic (from line 833 onwards in wp-includes/user.php) is based on user roles.

If the roles were created by a theme or plugin which is then deactivated, wordpress loses count of the users, but still lists them. The behaviour is confusing and inconsistent. See attached screenshot.

1) the user count total at the top (all) ignores the users with no 'active' role, however users are all listed (the users are shown as 'no role' in the list)

2) the old roles are shown in the dropdown selection however are not listed in the totals

Suggestions:

1) the total user count should at the very least be correct wrt to the list.

2) Perhaps a total of 'no role' users could/should be shown (since the users are listed anyway ?)

3) If the old roles are shown in the dropdown, perhaps they should be flagged as inactive in some way?

Related: [13576], #11914

Related: #17860