bug#48409: Text runs away before user can copy it

[Juri Linkov]

>   Otherwise, COMMAND is executed synchronously.  The output appears in
>   the buffer ‘*Shell Command Output*’.  If the output is short enough to
>   display in the echo area (which is determined by the variables
>   ‘resize-mini-windows’ and ‘max-mini-window-height’), it is shown
>   there, but it is nonetheless available in buffer ‘*Shell Command
>   Output*’ even though that buffer is not automatically displayed.
>
> (The user manual has a similar text.)
>
> So the text you want is still available in an Emacs buffer, and you
> can take it from there.

I vaguely remember a feature that clicking on the echo area
pops up the *Messages* buffer with the recent messages
at the end of the *Messages* buffer.  So Jidanni could just click
on the shell output in the echo area, and copy the complete output
from the displayed *Messages* buffer.

But this feature doesn't work anymore.  Searching the source code
indicates that such a feature existed before.  In minibuffer.el:

(defvar minibuffer-inactive-mode-map
  (let ((map (make-keymap)))
    ...
    (define-key map [mouse-1] 'view-echo-area-messages)

But now clicking mouse-1 reports an error.