FWD: Explanation Request for the Function set-transient-map in subr.el

[xenodasein]

Date: Nov 11, 2021, 21:10
From: xenodasein@tutanota.de
To: help-gnu-emacs@gnu.org
Subject: Explanation Request for the Function set-transient-map in subr.el


> What does this section do? In what situations this-command gets called using 
> keys of the transient map but it is not equal to itself? What does mc mean?
>
> ((eq t keep-pred)
>   (let ((mc (lookup-key map (this-command-keys-vector))))
>   ;; If the key is unbound `this-command` is
>   ;; nil and so is `mc`.
>     (and mc (eq this-command mc))))
>