Player movement favors x axis when in a corner

When you jump out of a corner, you don't move diagonally but either east or west (along the x axis).

To reproduce

1. Position yourself in a corner
2. Look exactly diagonally
3. Press forward
4. Press jump
   → You're jumping either into positive or negative X direction, no matter what

Videos

• https://gyazo.com/5a8e2b5f34391d3adc82b1b6e3f97c6c
• https://bugs.mojang.com/secure/attachment/359448/bug.mp4