I try to use a simple intersect in QGIS 2.18.10 and I get Unexpectedly results.
first I have two polygons :
second I use SAGA intersect algorithm and I get this layer:
Until now all good(not really good).
now I think new intersect layer is correct because that created from polygon 1 and polygon 2.
but if I use to difference algorithm to see if my new layer is correct then I take topology difference error at intersection line from two polygons
like this :
that is because at intersection area of two polygons don't have common vertex.
here like this image :
that create topology errors.
How can I fix that or create new intersect without this error using QGIS?