Stephen Berman <stephen.berman@gmx.net> writes:

> On Wed, 16 Sep 2020 13:54:03 +0800 積丹尼 Dan Jacobson
> <jidanni@jidanni.org> wrote:
>
>> What's the deal? All the completions start with a "*",
>> so why doesn't the one being built in the minibuffer have it?
>
> It's not just "*" but any string that all completion candidates share.
> I think this is related to the issue raised in bug#38476 (which is a
> feature request following on bug#38458).

It's kinda similar, but in this case the problem is more glaring -- all
the completion candidates share the same prefix, so why isn't that
prefix included in the completion string?

Here's the reproducible test case:

(progn
  (switch-to-buffer "foobar1")
  (switch-to-buffer "foobar2")
  (switch-to-buffer "*scratch*")
  (call-interactively 'switch-to-buffer))

Eval and then type `bar TAB':