Text fields don't scroll while selecting text with Shift

The bug

If you have a text, in the chat box or in a command block or structure block or etc, that is too long and can't be showed up completely, and you try to select a part of it with holding Shift+Arrow, the selection continues beyond whats already being displayed in the text field but the text field doesn't scroll to see what you are selecting.

Examples

The bug in action:

• 2018-12-05 17-05-17.mp4
• (Bug) When selecting text in a command block the text does not scroll.mp4

What is supposed to happen:

• (Expected) When selecting text in a command block the text does not scroll.mp4

Code analysis

Code analysis by null in this comment.