As demonstrated in the following video, apparently non-player entities riding minecarts can now move the minecart randomly while doing so. They can do this even against the pull of a Locomotive.

https://www.youtube.com/watch?v=qiFSU6qnrag

Well first attempt is only partially successful. I disabled the AI tasks when riding, which works, pigs don't follow carrots anymore. However it doesn't seem to have stopped random wandering and running when hurt.

I don't actually know which code has authority over ridden entity control translation. Kind of hard to fix without knowing that.

damn should have reimplemented the pigs following carrots... i could have amde a nice minigame :P

I think you should work on minecart instead of entity ai code.

Nothing I can do unless I can find what is modifying the motion vector.

Isn't this fixed?

Not completely. Random wandering still causes carts to move.

The code is in EntityMinecart#update block, which we have little control over. Thus, we cannot really fix this.

@CovertJaguar So what do we do on this?

Nothing, unless you want to dig into the entity movement code.

By the way MinecraftForge/MinecraftForge#4665 may fix this issue once accepted.

Now by overriding a method, I think I managed to fix this issue. Will push soon

It is fixed; a pig can no longer pull a creative locomotive.

I assume that fully Railcraft objects give one more control, so what about a "cage-cart" that disables riding NPCs' AI/movement?

Or if disabling AI/movement is not actually a thing, would it work to have a "cage-cart" that stores the entity, ala MFR safari-net, and then renders said stored entity to appear inside the cage?

At worst, I'm pretty sure that you can add an AI task that prevents movement tasks from executing.

@purpleposeidon yes, that's pretty simple actually