CTRL / CMD key get stuck on OS X / Text Box Backspace deletes whole word or whole line on Mac and Linux

When I open my inventory and go to the search tab, I enter something in and everything goes wonky. I am done searching so I press backspace and the entire search term disappears. I enter the chat to say hi to my friend who just joined, I misspelled his name and I tried deleting the accidental character, and the entire name disappears. Say his name was George, and I type Goerge instead. I would press backspace, and all "Goerge" would disappear. (Get what I mean?) This happens until I completely re-start the game.

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Delete whole word: CTRL is stuck, delete whole line: SHIFT is stuck.

Steps to reproduce on OS X:

1. have Minecraft and at least one other app open in fullscreen mode
2. open chat, type a few letters
3. holding ⌘, switch the other fullscreen app by swiping left/right with 4 fingers on the trackpad (⌘⇥ also works if you press ⌘ quickly enough while the app switch animation is active)
4. release ⌘
5. switch back to Minecraft
6. press A. This will select the text you typed instead of writing the letter A.