Going from the Overworld to the Nether doesn't spawn the player inside the Nether side portal

When using an Overworld portal to go to the Nether the player does not spawn inside the Nether side portal. 

What I expected to happen was...:
I would go to the Nether an spawn in the portal

What actually happened was...:
I spawned at the Y coordinate for the Overworld portal and not the Nether side portal resulting in me dropping several blocks onto the top of the portal frame. For another portal I spawned inside the Netherrack several blocks diagonally from my portal.

Steps to Reproduce:
1. Have a portal in both the Overworld and Nether
2. Enter the portal from the Overworld