Here is an example where it matters:

(defmacro test (exp)
  (macroexp-let2 nil res exp
    `(progn
       (f ,res)
       (g ,res))))

(note that the `progn' is mandatory here.)  Without the patch:

(macroexpand '(test (+ 1 2)))
==>
(let*
    ((#:res #1=(+ 1 2)))
  (progn
    (f #1#)
    (g #1#)))


After patch:

(macroexpand '(test (+ 1 2)))
==>
(let*
    ((#:res #1=(+ 1 2)))
  (f #1#)
  (g #1#))


(And is it currently allowed to push this to master?)


Thanks,

Michael.