bug#18285: 24.3.92; A combination of `display' on text and `invisible' and `before/after-string' leads to the before/after string being displayed twice

[Dmitry Gutov]

On 08/21/2014 06:07 PM, Dmitry Gutov wrote:

> The workaround of replacing
> `before-string' + `invisible' with just `display' seems to function just
> fine so far. For some reason, Nikolaj opted to render the completion
> tooltip in Company with the former option, so I tried not to change it
> too much.

And now I know why that was: `display' doesn't work on empty overlays, 
but `before-string' and `after-string' do. That means +1 workaround.

This comes up when the Company tooltip is displayed "after" the end of 
the buffer.