l3backend: adding new DVI specials?

[Joseph Wright]

On 13/02/2020 23:16, Karl Berry wrote:
>      that's exactly what is happening.
> 
> Oh. Well, good :). So how do dvipdfmx and dvisvgm come into it?

If a user doesn't give a backend option in DVI mode, they get dvips. But 
if they are actually using dvipdfmx or dvisvgm (say with no graphics so 
not 'worrying'), then the latter has to deal with an 'unexpected' 
\special line.

> Just to ignore the special in case the user gives them a dvi file that
> was processed with backend=dvips (so to speak)?

Yes

Joseph