Dear LuaTeX team,
I am not really sure if this email list is the right one to address this email to, but I hope the report reaches the right developers. If you can tell to which address I should send this report, too, then feel free to name the address or to simply pass on my mail.
So now the report: Today I installed the new TeXLive 2016 and have found that the MathKerning seems to be disabled in LuaLaTeX and in ConTeXt as well. In TeXLive 2015 everything did work fine. I have attached a minimal working example and two outputs: One done by TeXLive 2015 and it’s LuaTeX version, and one by TeXLive 2016 with the updated version of LuaTeX. You can see that the MathKerning for the indices and for the integral borders is not working in the version produced by TeXLive 2016. I compiled both versions under MacOS X (newest version). I did not test Windows or MikTeX and I have tested various OpenType fonts and all of them showed up the same behavior.
Yours sincerely
Mathias Schickel