(Player) Head in inventory causes buggy rendering of certain inventory slots, potion effect display and attack cooldown

If you have one or more custom player skulls in your inventory, the off-hand slot background will change to display a strange white, black, and gray texture, unless:

• You have moused over a slot equal to or later than the last slot containing a custom head.
• There is an item in a slot after the last slot containing a custom head.
• There is an item in the off-hand slot.

Additionally, if a custom skull is placed in the helmet slot, all other armor slots will gain a black background. Mousing over one of the armor slots or placing a piece of armor in one of them fixes all later armor slots, but color shifts the background of the armor slot in question to different shades of gray. Also, If a custom player head is the last item in your hotbar, the attack strength indicator has a solid black background instead of being transparent.

This bug affects both creative and survival game modes.

To reproduce:

1. • Give yourself a custom skull with the command

     /give @p skull 1 3 {SkullOwner:AnyPlayerName}

   • Also the head from the creative inventory works
2. Mess around with it in your inventory.