Currently, the renderer for polygons draws both an outline and an area fill. The fill depends on whether we are using wireframe mode, partial fill mode, or full-fill mode:

As of right now- only the fills are targetable for node snapping. This needs to be changed- we should allow only the outlines to be snapped/connected to, but that's not ready yet.

Here's an example of what this looks like when trying to add a new node to a polygon:

The behavior here is not intuitive- the node is being snapped to the edge of the polygon since RapiD thinks the way is being 'snapped' to.