What is the bug:
This bug hides the player arrow under a map held by the player.
What causes this bug:
If you place a map on an item frame then copy that map to your hand in Creative (affects both gamemodes), leave the server or quit the game, and join back, the green arrow(s) showing maps on item frames are still there, but the player's white arrow is hidden under the map; it can be seen when the player moves out of the boundaries of the map (may only affect maps that have been zoomed out using paper, unconfirmed).
Evidence of this bug in action can be seen in the following image.