forward_line(buffer, body_lines) is not a real scrolling. We need to move the top_line to have a nice effect.

flush the net ibuf too

and while there improve the error message.

After a resize we should do the endwin+refresh+clear dance, but in other situations, like when entering the minibuffer, we can simply re-wrap the page and move the windows. This prevents a small flash when entering the minibuffer, as well as fewer redraw (redraw after the command and shortly after because it was scheduled).