Inifinite loop in ACLFilledChecklist

I'm now seeing an infinite loop of callbacks in ACLFilledChecklist while
starting 3.HEAD.
ACLFilledChecklist::checkCallback(allow_t answer)
{
     debugs(28, 5, "ACLFilledChecklist::checkCallback: " << this << "
answer=" << answer);

     /* During reconfigure, we can end up not finishing call
      * sequences into the auth code */

     if (auth_user_request) {
       ... play with auth ...
     }

     ACLFilledChecklist::checkCallback(answer); // may delete us
}

What is this meant to do when the ACL is a non-auth type?

Amos

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