How *not* to highlight

[Juliusz Chroboczek <jec@dcs.ed.ac.uk>]

Hello,

I was thinking how to keep Gnus from highlighting when some face stuff
has already been done, e.g. by a MIME decoder.  The problem is that if
the preprocessor changed some faces, then the Gnus highlighting
functions will just undo its work.

What I currently do is to check in the function
gnus-article-maybe-highlight whether

   (text-property-not-all (point-min) (point-max) 'face nil)

in the article buffer.  If it is the case, no highlighting is done.

Of course, this is not the right approach.  This means that if a face
has been changed, say, in the body of the article, then neither the
headers nor the signature will be highlighted.  Furthermore, it does
not inhibit spurious highlighting in the summary buffer.

I've thought about doing a similar check in the function
`gnus-add-text-properties', but then any function that sets text
faces would have to make sure that those will not be overridden
later.  Or should I add a function `gnus-set-text-face', which would
be called by all the highlighting functions?

By the way, I believe that this modification should find its way into
the distribution of Gnus.  It does not cost much, and as highlighting
is only there for esthetics, a preprocessor should be able to override
it.

Just if you're interested: I need this for some character set support
that I've added to TM and RMIME.  Feel free to browse

    http://www.dcs.ed.ac.uk/home/jec/charset/


                                        J. Chroboczek