On 19 September 2016 at 13:29, Gavin Smith <gavinsmith0...@gmail.com> wrote: > \indexlbrace ->{\ifmonospace \else \ecfont > \fi \char 123}
I don't know where this definition is coming from: it should be the following definition: \def\lbracechar{{\ifmonospace\char123\else\ensuremath\lbrace\fi}} which, as you can see, doesn't use \ecfont. Are you sure that you are using the texinfo.tex from Texinfo 6.3?