> From: João Távora <address@hidden>
> Date: Tue, 29 Jan 2019 19:33:33 +0000
> Cc: Johan Bockgård <address@hidden>,
> emacs-devel <address@hidden>
> > > > A 'face' property is documented for general use only for text, not for
> > > > symbol plists.
> > > (put 'rng-error 'face 'rng-error)
> > I don't see how this contradicts what I said. Do you?
> Well you did say that 'face should *not* be put on symbol plists,
> but the documentation and the code states otherwise.
A single well-documented exception doesn't invalidate the rule.
You must mean the unwritten, inadvertently created rule, right? Ok, no problem, exceptions are fine as long as we document them.
But I think flymake is using the exception that I meant to document, i.e. it is using overlay categories. It can either stop using them or change the face name. Both alternatives are backward incompatible to users, thought perhaps not "by much", as that part of flymake might have been a wee bit overdesigned. Have to check better.
I still wonder, as Daniel, if using some other symbol for the display code would be very disruptive.