Clean up term_access when a role gets deleted

I believe this is still an issue in the 6.x branch; need to test.

Working on this. (Thank goodness D7 supports foreign keys... if only D6 did.)

I never realized this before, but there are no hooks associated with role deletion:
http://api.drupal.org/api/function/user_admin_role/6
http://api.drupal.org/api/function/user_admin_role_validate/6
http://api.drupal.org/api/function/user_admin_role_submit/6

So, without referential integrity, all we could do is add form overrides to clean out the stale data.

Dialing this down to minor since it doesn't affect functionality and the number of roles tends to be small in comparison to other data types.

One place we might be able to do this cleanup without much overhead is on visits to the admin page. That form already checks the list of existing roles against those found in TAC tables.

There is a need to add hook_user ffor role deletion in TAC. As i see, it is missing.

hook_user() doesn't get invoked when a role is deleted, though, not that I can see. (See in http://api.drupal.org/api/function/user_admin_role_submit/6). That's the problem. (There is a hook for it in D7, though.)

You're right. I checked: user_admin_role_submit().
I forget about it. That can be why i have not inserted hook_user into TAC before.

Your idea in comment #5 seems ok. OR we should postpone this until D7 version.

That seems reasonable too.

In D7 we can merely implement hook_user_role_delete().

http://drupalcode.org/project/taxonomy_access.git/commit/775ff2f