[GRASSLIST:3811] overlay

[leo.lami at katamail.com]

Hi,
I have a problem with th v.overlay command.

I have two vectors (imported by OGR from shapes) that have several boundary 
completely overlapped because one derive from the other. 
If I use v.overlay with "and" option I have a vector that is not the correct 
intersection of them.

How you can see from the png file linked, same polygons of the first vector 
(with one boundary overlapped with the boundary of the other vector) are not 
included in the intersection vector (bottom of the picture).
In the oter case you can see that, in the same situation, I have the polygons 
included in the intersection vector (top of the picture).
The first vector has black line and no filled area, the second has red line 
and not filled area and the intersection vector has green line and yellow 
filled area.

Someone had the some problem or does someone know the cause?

Thank you
Leonardo Lami