Spacing with Font Roboto

[Ulrike Fischer]

Am Mon, 9 Dec 2019 16:12:46 -0700 schrieb Karl Berry:

> if I change that line to
> \usepackage{roboto}

then you wouldn't use the roboto font in the example, as roboto is a
sans serif font.

\usepackage{roboto} + \sffamily shows the same (wrong) behaviour for
me. 

Actually Marcel just commented on the luaotfload issue:

================
This is an artifact of how LuaTeX handles font with non-standard
upem values. The Roboto font bundled with TeXLive has been converted
from TrueType to OpenType without changing upem from 2048 to 1000.
LuaTeX tries to work around viewer bugs by forcing upem to 1000 and
fixing the differences by changing the font size and adding kerning.
This is detected as spaces by some viewers. There is not much we can
do here. LuaTeX could be changed to behave similar to XeTeX, but
that would reintroduce multiple issues with buggy printers.

The best fix would be to avoid such fonts altogether. For example by
using the original TTF fonts instead of converting them to OTF (This
actually used to be the case up to 2018 and it is the reason why the
problem only occured for some people: If Roboto is installed as
system font, the TTF system font is used) or by using a normal upem
value of 1000 for the OTF version.
================

-- 
Ulrike Fischer 
https://www.troubleshooting-tex.de/