The mouse needs to be double clicked for clicks to register if you go from windowed to fullscreen while the game is on the loading screen (the one with the progress bar).

What I expected to happen was...:
The game to register single clicks.

What actually happened was...:
A double click is necessary for the game to recognize the mouse clicking (and it doesn't even always register the double clicks either).

Steps to Reproduce:
1. Start Minecraft in windowed
2. Go fullscreen while the game is still loading on the progress bar screen.
3. After the game finishes loading, try clicking a menu button. It doesn't work, so try doubling clicking the menu button. This happens with all mouse interaction even in game.