RE: Same file on two buffers - Two different major modes

[Drew Adams]

> The principal idea is to have the same buffer next to each other,
> where one can change the major mode on each buffer, but saves
> to the save buffer.

OK, that's "the principal idea", but I don't understand the
use case. Could you say why you want to see the same buffer
in two windows, but in a different mode in each window?

What is it you are really trying to do?  That might help
understanding.