bug#38457: 27.0.50; dabbrev-expand regression due to message change

[Juri Linkov]

> Here's something that's a matter of taste, but:
>
>> +      (setq message (if (string-match-p "\\` *\\[.+\\]\\'" message)
>> +                        ;; Make sure we can put-text-property.
>> +                        (copy-sequence message)
>> +                      (concat " [" message "]")))
>
> I prefer how it looks without an extra space here. Meaning
>
>   (concat "[" message "]")
>
> instead of
>
>   (concat " [" message "]")
>
> . Apparently minibuffer contents always end with a space already?

For compatibility with minibuffer-message this code was copied
from minibuffer-message.  And indeed there is only one space
between the minibuffer contents and the message.  If you see two spaces,
maybe this is due to misconfiguration?