The bug

I have already seen the "fixed" bug report MC-151333 but the villagers still get stuck in the water. I have been trying to make a swamp village in a part of swampland that has no exposed land anywhere but the villagers keep jumping in the water and once they do they just swim in it.

I have found that the pathfinding is broken in where they still swim in the water but they can't seem to detect a bed where they need to swim out of the water and then onto land to get to it. As soon as I push the villager onto land he goes to the bed.

In the picture below a villager is in the water right beside a bed at night but isn't going into it.

How to reproduce

See @Gintoki in this comment and this video.