[Freefont-bugs] Large rectangle with stretchy U+2F/U+2211/U+27E8/U+27E9 and GNUFreeFont

[Frédéric Wang]

Hi all,

Here is a testcase with a dev version of GNUFreeFont:
http://fred-wang.github.io/MathFonts/GNUFreeFont/

As I understand, stretchy U+2F/U+2211/U+27E8/U+27E9 do not have a "glue"
so we connect them using a rule

https://dxr.mozilla.org/mozilla-central/source/layout/mathml/nsMathMLChar.cpp#855

but the rule thickness has the width of the parts, which leads to these
ugly large rectangles.

What do you think? Is it a bug due to our limited implementation of the
MathVariants table (bug 963147)? Or is it incorrect for a font to
specify a stretchy operator construction without any extender?


-- 
Frédéric Wang
maths-informatique-jeux.com/blog/frederic