Is this a bug in while-let or do I missunderstand it?

[arthur miller]

(progn

  (while-let ((run t))

    (message "Running")

    (setf run nil))

  (message "out of loop"))

It ends in infinite recursion. setf/setq have no effect on the lexical variable.

I tooka look, but I don't understand why is it necessary to build while-let  on

if-let. This simplified version did it for me:

(defmacro while-let (spec &rest body)

  "Bind variables according to SPEC and conditionally evaluate BODY.

Evaluate each binding in turn, stopping if a binding value is nil.

If all bindings are non-nil, eval BODY and repeat.

The variable list SPEC is the same as in `if-let*'."

  (declare (indent 1) (debug if-let))

  (let* ((bindings (if (and (consp spec) (symbolp (car spec)))

                           (list spec)

                         spec))

         (variables (mapcar #'car bindings)))

    `(let* ,bindings

       (while (and ,@variables)

         ,@body))))

(progn

  (while-let ((run t))

    (message "Running")

    (setf run nil))

  (message "out of loop"))  => "out of loop"

Or did I missunderstood how to use while-let in subr.el?