l3backend: adding new DVI specials?

[Martin Gieseking]

Am 13.02.2020 um 08:54 schrieb Joseph Wright:
> Initially, we simply added everything as \special lines directly 
> containing the PostScript, but that leads to warnings with dvipdfmx if 
> the right backend isn't selected. It also meant there was lots of 
> material in the \showbox output. Moving it to a .pro file meant that 
> inclusion used only one line
> 
>      \special{header=l3backend-dvips.pro}
> 
> and this line is simply ignored by dvipdfmx. We realised that other 
> systems might not know this one line, but felt that it was hopefully 
> possible that a similar '"skip header=" lines' might be added to any 
> cases. The one we had in mind was dvisvgm: I'm not familiar with pyxplot.

Hi Joseph,

Karl told me about this this discussion a couple of hours ago. So here's 
a slightly delayed info on dvisvgm regarding "header=" specials:
dvisvgm supports all dvips specials including "header=" and processes 
them accordingly. Actually, it nicely converts most DVI files created 
with the dvips backend. Therefore it shouldn't be necessary to change 
the handling of "header=" specials. dvisvgm will most likely swallow the 
planned additional special unnoticed.

Best regards,
Martin