RE: highlight-changes-mode

[Drew Adams]

> I think the real question is which way we want global minor modes to
> work.  Do we want the global mode command to affect only buffers
> created subsequently?  Do we want it to affect all existing buffers?
> Only existing buffers in which the user has not specified any
> setting for the mode?

My opinion:

I want turning on or off a global minor mode to affect all existing and all
future buffers (until another explicit mode change). Anything else would be
a nuisance, in addition to being confusing.

There may be some particular global minor modes that one doesn't want to
turn on or off in particular buffers, but they should be handled as special
cases. The general case should be to treat a global minor mode as, well,
global - to have it do for all buffers what a local minor mode does for the
current buffer.