bug#22111: 25.0.50; (this-command-keys) doesn't return prefix keys

[Eli Zaretskii]

> From: Artur Malabarba <bruce.connor.am@gmail.com>
> Date: Mon, 07 Dec 2015 22:09:21 +0000
> Cc: 22111@debbugs.gnu.org
> 
> Alan Mackenzie <acm@muc.de> writes:
> 
> > I don't think this is a bug: C-u is bound to command
> > `universal-argument', and it works by setting `prefix-arg'.  Once it's
> > done that, `univeral-argument''s runtime is finished.
> 
> That's what I thought at first, but the docs say it should.
> See the docstring of `this-single-command-keys' or the elisp manual on
> this function.

Can you bisect to see which commit caused this?