On 22/03/2021 15:58, Don Hosek wrote:
> fontdef.dtx defines the various series, family and style defaults using \newcommand, e.g.
> 
> \newcommand\itdefault{it}
> \newcommand\sldefault{sl}
> \newcommand\scdefault{sc}
> \newcommand\updefault{up}
> 
> This gives defines them as \long However, the commands \fontfamily, \fontseries and \fontshape define \f@family, \f@series and \f@shape using \edef which maked the resulting values not \long
> 
> This means that code that would do something like, e.g., \ifx\f@shape\itdefault…\fi will not work as expected.
> 
> The simplest fix would be to use the starred form of \newcommand for setting the various \XXdefault values. I would imagine that this should not break anything
> 
> -dh
> 

They have been like this *for ever*: it's a feature I would say.

Joseph