Undershoots are often caused by inaccurate digitizing or when converting scanned data. Using the Extend Undershoots cleanup action, you can locate objects that come within the specified tolerance radius of each other, but do not meet.
If one object can be extended to cross the other, it will be extended (while maintaining the same direction) and snapped to a point on the object. If no node exists, one will be created at the intersection.
Objects that end short of another, inside the tolerance, are extended. Move your cursor over the image to see the results.
The Extend Undershoots action works in the same way as works with undershoots, except that with Extend Undershoots, you must select the Break Target option to break the target linear objects at the intersections.