Re: functionp bug

[Richard Stallman]

I think that change in functionp should be reverted.  Any change in
such things tends to cause problems, so it is better to leave them alone
unless there is an important problem to be fixed.

Theoretical arguments trying to show that "this behavior couldn't
possibly be right for any caller" tend to be unreliable.  Whatever
functionp does, code will have come to depend on it.