Feature request #4384
ftools: expose an (geos) option in the qgis gui to do some snapping/renoding before running an union
|Pull Request or Patch supplied:||No||Resolution:|
merging polygons with "dirty" geometries (0 size areas, slivers) causes to get incorrect results.
Adding an option to set tolerance during geometry union operations (as Arc* does) will help the user to get their results without using tools like GRASS.