Re: C-n is very slow in Font-Lock mode

[Richard Stallman]

    So for its correct behavior, it is mandatory to do the font locking.
    The only exception to that would be if the user would have specified
    that it is ok to work with unfontified text.

You are right.  I will change it back.

    One way to do that is to set jit-lock-defer-time.

Are you suggesting this as a change in the defaults?
I'm not interested in this as a workaround for me alone;
I want to make it faster for everyone.

I found a way to change line-move-1 not to use vertical-motion
in simple cases.  I think it should work, but I don't understand
the reason why the code uses vertical-motion.

Can anyone add a comment to explain why?