RE: completion-auto-help

[Drew Adams]

    > minibuffer-setup-hook is used for all
    > entrance to the minibuffer, not just for completion functions.

    > I'm looking for a hook specific to completion.  I think we
    > still need a hook that runs whenever a completion function
    > (e.g. completing-read) displays its prompt.

    Check the value of minibuffer-completion-table in your hook.

Not sure what you mean. Do you mean to check, inside the hook, whether that
var is non-nil, and use that test to determine whether or not we are
completing? That is, use (not (null minibuffer-completion-table)) as a kind
of `completing-p'?

If that's what you mean, it doesn't seem to work -
`minibuffer-completion-table' is not nil, even when doing things like
read-from-minibuffer (which doesn't use completion).

Hoping I misunderstand and there is a simple solution.