bug#57792: 29.0.50; async-shell-command fails with prefix-argument on -master

[Lars Ingebrigtsen]

Stefan Kangas <stefankangas@gmail.com> writes:

> I can reproduce this bug on master, 27.1 and 28.2.  Here's a test case
> (not tested):
>
> (ert-deftest simple-tests-async-shell-command-57792 ()
>   "Test for https://debbugs.gnu.org/57792 ."
>   (with-temp-buffer
>     ;; Pretend we have a prefix argument.
>     (async-shell-command "echo \"test\"" '(4))
>     (should (equal (buffer-string) "test"))))
>
> I'm not sure what behavior we want here, though.  Should we insert the
> command output directly at point in the current buffer, or should we
> first insert it into "*Async Shell Command*" and copy it over when done?

The prefix isn't documented to do anything (and currently bugs out), so
perhaps we should just remove the prefix from the interactive spec
instead?

Is the intention that `C-u M-&' insert the output in the current buffer?