Eli Zaretskii <eliz@gnu.org> schrieb am Fr., 3. Feb. 2017 um 16:10 Uhr:

>
> > This is a regression: it still works as expected in Emacs 23.4, but no
> longer in Emacs 24.3. Probably
> > something about this-command-keys or command-execute changed in the
> meantime so that the code in
> > novice.el no longer works as expected.
>
> Yes, this-command-keys returns just "^M" instead of the expected
> "\370erase-buffer^M" it returned in Emacs 24.2 and older.
>


git bisect says

b593d6a999b21dfee6939b24866a5ec6fbe7d11b is the first bad commit
commit b593d6a999b21dfee6939b24866a5ec6fbe7d11b
Author: Aaron S. Hawley <aaron.s.hawley@gmail.com>
Date:   Tue May 1 12:10:02 2012 -0400

    Reimplement execute-extended-command in Elisp.
    * src/keyboard.c (Fexecute_extended_command, Vsuggest_key_bindings):
    Move to simple.el.
    * lisp/simple.el (suggest-key-bindings, execute-extended-command):
    Move from keyboard.c.

:040000 040000 980a3efdb92bf89c1042883830e7fbd1da063f3e
997099bae8bf4663aed645559b102345912f19fa M lisp
:040000 040000 832414759411034e7cea2c694fdb77273c422b05
ccf76976dd740fc43ccf84c35ddaf9efe19d5ec2 M src

That looks reasonable given that it touches code closely related to the
disabled command functionality.