Thanks, Hookers.
So the pig can basically pass through or bounce off the target (or technically, off of the farthest melee radius), as long as the distance between the target and the end-point does not exceed the distance between the target and the origin.
For example, if I Pigcharge beginning 3" away from the target, the pig may end the movement within melee range of the target or anywhere within a 3" radius of the target. It may not move up to its full Cg distance if that movement places the pig further than a 3" radius from the target.
If I may speculate....I doubt the designers wrote the last sentence of the "Toward/Away From" definition considering what effect it would have when combined with the Pigcharge. I suspect it was written to prevent using circuitous routes as a means to defeat the intent of "move toward the target using the shortest route". That said, the combined effect is close enough to what I think they want to achieve with Pigcharge. A little flaky, but close enough.
If it were up to me, I'd specify that Pigcharge requires the model to Push to the target, and then optionally permits the model to Push further, not to exceed its Cg distance for the total movement for the action.