The player model in the inventory screen renders in the wrong orientation when it's not standing up straight

The bug

When the player is flying, the model in the inventory doesn't shifting its body correctly relative to the mouse position. For example, suppose the game is set to full-screen. If your cursor is at the left side of the screen, the model would look towards your cursor correctly. However, if your cursor is at the right side of the screen, the model would be shifting in the opposite direction relative to the cursor.

This issue does not seem to affect the player's swimming pose.

How to reproduce

1. Equip elytra
2. Fly using your elytra
3. Open your inventory menu
4. Move your mouse around, especially to the left and right side of Minecraft (or screen, if you're playing in full-screen mode.)
5. Note the model's behavior in relation to the mouse cursor

History of this issue

Originally, this ticket was reported for the inventory screen if the player is dead/dying. However, as of 15w41b, the inventory now closes when you die. It has then been suggested that this issue also occurs when opening the inventory after right-clicking a bed, but before getting into it. This video shows how that looks as of 20w07a: https://youtu.be/1bJgALyjt1Y.