The constant cursor display must be suppressed whenever a message
was printed to the status bar. That is: whenever 'lastmessage' is
something other than 'VACUUM'.
By default, this function is bound to ^L, to make that keystroke do
something actually useful. To not lose the Refresh function that this
keystroke had, the centering function additionally does a full redraw
and refresh of the screen.
This gives quicker feedback, and spares the user unnecessary beeps
and typing. Also, now a beep after a <Tab> means just one thing:
there are NO completions.
This fulfills https://savannah.gnu.org/bugs/?58627.
The parameter was referenced in just one place. So, simply check for
the three relevant menus (and unrestricted mode) and be done with it.
This also has the pleasant effect that the menu name is now the first
parameter of do_prompt(), thus clearly indicating what prompt it is,
instead of having an opaque TRUE or FALSE value at the beginning.
Benno Schulenberg