Bugs with rails and minecart

^{Update by [Mojang] Mega_Spud (Jay Wells):}
Summary:
When travelling in a minecart, as the cart turns around a corner, black lines will appear on any blocks that are directly adjacent to the rails as you travel past them.

Steps to Reproduce:

1. Ride a minecart on a rail that changes direction

Observed Results:
Black lines appear around the edges of blocks as you turn

Expected Results:
The blocks shouldn't render any differently

Screenshots/Videos attached: Yes

Notes:

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Original Description:
A very annoying thing is happening with the rail and the minecart, when I'm inside it the edges of blocks around it turns black!