Re: Fixing r-tree semantics

Hmmm ... just when you thought it was safe to go back in the water ...

I was only looking closely at the "box" case earlier today, assuming
that the polygon code was set up identically. Well, it isn't. In
particular it appears that the poly_overleft and poly_overright
definitions are different from box's, which means that rtrees are
still broken for polygon searches.

I'm of the opinion that this is a flat-out bug and we should just
fix it, ie, change the operator definitions. The polygon definitions
aren't even self-consistent (overleft accepts equality and overright
doesn't).

poly_left
result = polya->boundbox.high.x < polyb->boundbox.low.x;
poly_overleft:
result = polya->boundbox.low.x <= polyb->boundbox.high.x;
poly_right:
result = polya->boundbox.low.x > polyb->boundbox.high.x;
poly_overright:
result = polya->boundbox.high.x > polyb->boundbox.low.x;

By analogy to the box case these should be

poly_overleft:
result = polya->boundbox.high.x <= polyb->boundbox.high.x;
poly_overright:
result = polya->boundbox.low.x >= polyb->boundbox.low.x;

regards, tom lane