I have a set of vector lines in grass which I need to convert into polygons. However, because of bad base data, the polygons don't always close. To fix this, I need to extend each disjointed line by a certain distance and connect it to the first line it hits. The problem is that I can't figure out how to do this. I have experimented with v.clean, v.generalize, v.edit, and (converting to a thinned raster) r.grow, r.neighbors and even r.flow, but I can't find anything which will let me do this.
Can anyone point me to a tool that would do this?