Re: Font-lock in COMINT modes

[Richard Stallman]

    My presumption is that '(nil) and nil must differ in some other
    way (aside from the unintended side effect of changing the default
    non-keyword fontification), since the original change from Sept.
    explicitly bound f-l-defaults non-nil, which by inference suggests nil and
    '(nil t) would exhibit this same difference, whatever it is.

It affects facemenu.  I am pretty sure that was my motive
for making the change.

However, if it also makes things a lot slower, that is not good.
Has some font lock expert verified that this is really happening?

If so, we should set up a way to turn off facemenu for faces while not
turning on the Font Lock mechanism unnecessarily.

One way is for Font Lock to notice the value (nil t)
specially and not turn on the mechanism.

Another way is to have another variable to disable the faces menu
with.  That way is very safe.