Subject: bug#52374: keymap-lookup with prefixes returns nil

From: Stefan Kangas <[email-masked]>
Date: Wed, 8 Dec 2021 13:21:10 +0100

Run emacs -Q, type `M-x re-builder RET' and then `C-c C-q':

Now evaluate:

    (lookup-key reb-mode-map "\C-c")
    => (keymap (21 . reb-force-update) (2 . reb-change-target-buffer) ...)

Compare this to:

    (keymap-lookup reb-mode-map "C-c")
    => nil

Is the second result expected, or is it a bug?