font-lock and fontifying the few first nonempty lines in a buffer

[Ulf Andersson]

Hello,

I'm sorry if this is a trivial question asked too many times,
but i couldn't find it.

I'm trying to write a major mode for Emacs, that need to fontify the few
first nonempty lines in the buffer. The mode do some other coloring in
addition to this, and that works OK. So far I have experimented with
`after-change-functions' and function matchers in `font-lock-keywords',
but all I manage to do is sending my Emacs into an infinite loop deep
down inside. I have to kill it from outside to get out of the lockup.

I am using emacs 21.2.1 in a Windows 2000 environment.

Has anyone already done somthing similar?
Is there an `obvious canonical way' to do this?
Is this downright impossible to do using `font-lock'?

Thank you all for your time and effort.

  /Ulf Andersson