X11 primary (middle mouse button) not supported

[byteit101]

The X11 primary selection (select to copy, middle mouse button to paste) isn't supported. This is frustrating as most applications on Linux natively support this method of editing text.

[byteit101]

For context, I have patches that support this in terminalfx and hterm, but upstream needs convincing: https://issuetracker.google.com/issues/41452856?pli=1