Why is --reintegrate neccessary?

Hi there,

I've had a discussion with a collegue yesterday and he wondered why
--reintegrate is neccessary for reintegration merges at all. He supposed
SVN should be able to determine that the intended merge is a reintegrate
by looking at the mergeinfo.

So, this is just a question out of curiousity: Why is it neccessary to
specify --reintegrate? Or: In which case would a potential
auto-detection fail?

Thanks,

Tino.

-- 
"What we nourish flourishes." - "Was wir nähren erblüht."
www.tisc.de