bug#1305: All code that currently beeps should use visual bell instead

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

>> IMO, the default behavior on GNU/Linux (inverting video on the first and 
>> last line of the frame) is horrible (but perhaps less so than an actual 
>> bell),

Hm...  when I try this on Debian/bullseye, it inverts the video on the
two first lines in the frame.  But I seem to recall it working the way
you describe, so perhaps there's differences between various
toolkits/libraries used by Emacs in this area?

>> and the default behavior on macOS is too intrusive (but again 
>> perhaps less so than an actual bell).
>
> On MS-Windows, we use a system API that flashes the caption bar of the
> selected-frame's window.

Then it sounds like visible-bell should be visible enough on all the
three major systems we support.

However, I just noticed that an "emacs -Q" doesn't beep at all on this
machine -- because I've switched off all "alert" beeps in the OS
interface.  So `C-g' just says "Quit" in the echo area, and nothing
else.

So in this instance, defaulting `visible-bell' to "on" would make `C-g'
more intrusive/obnoxious than previously...  which is the opposite
effect than what was originally discussed in this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no