bug#16196: 24.3.50; Disable ding when scrolling

[Eli Zaretskii]

> From: Jan Djärv <jan.h.d@swipnet.se>
> Date: Fri, 20 Dec 2013 07:08:37 +0100
> 
> I think Emacs should by default not beep at all when scrolling and no 
> movement can be done.

This could be hard to implement.  Most scrolling commands just examine
the text around point, and set the window-start for the next
redisplay, so they don't really know when no movement can be done.
Thus, the exact conditions for bitching "End of buffer" are not at all
what you could imagine, and not easily correlated with the situation
you describe.  For example, the next-line and previous-line commands
signal these errors when they find they are unable to scroll text,
something that might be utterly unrelated to hitting end of buffer.

> It should just ignore it and do nothing, like most applications do.

Well, "do nothing" is something Emacs cannot easily do in this case,
since the part that "does nothing" is redisplay, which has no idea
about the scrolling command that just ran.

>  At the very least there should be an option to turn off scrollrelated 
> beeping.

This should be much easier to implement, although you may be surprised
to see in how many places we throw that particular error.  (Hint: grep
the Lisp sources for "'end-of-file".)

Patches are welcome, as usual.