bug#34939: Some minibuffer behaviour is annoying

[Juri Linkov]

>> Messages in the echo area should never conceal the minibuffer.  Period.
>>
>> There is a special function minibuffer-message for this purpose:
>
> Shouldn't we make this behavior the default, then?

I agree it should be the default.  But unfortunately I have no idea
how to do this.  Both ways to catch error signals in the minibuffer:

1. Overriding the default error function with command-error-function;

2. Using condition-case like

  (condition-case lossage
      ... minibuffer reading ...
    (text-read-only
     (minibuffer-message (get (car lossage) 'error-message)))))

Both they override the default error handling called by
‘error-message-string’ in the function ‘print_error_message’
that performs many useful things that include logging of error
messages in the *Messages* buffer.  Overriding the default error
function will exclude this useful default behavior.