Meta causes text input to lose and regain focus, even if disabled

[m93a]

Describe the bug

When I disable the Meta key (or Super key) in settings, pressing it still has some unwanted and unintuitive effects. Bug originally described in this issue.

To Reproduce

Steps to reproduce the behavior:

1. Go to Keyboard in Switchboard
2. In “⌘ key behavior” select Disabled
3. Open this website in a browser: https://jsfiddle.net/r6co502L/1/
4. Click on the textarea
5. Write something
6. Press Meta

Expected behavior

Nothing should happen – the key is disabled.

Actual behavior

The textbox blurs when Meta is pressed and regains focus when it is let up.

Additional context

This can lead to problems for example when you bind a macro to it which is supposed to type something, or if you use a program that reacts to focus in a unorthodox way (for example Facebook's Messenger which changes your cursor's position on focus).

Platform Information

• [ ] I'm using the latest version from git that I've manually compiled
• [x] I'm using the latest released stable version