Steps to reproduce:
1. Run the main scene.
2. Continuously input any keys in the "input field".
3. Notice that the position of the cursor changes to

Expected result: the cursor of the input field should not jump when typing
Actual result: cursor jumps at the end of the visible area of the input field

Reproduced in: 5.5.4p4, 5.4.6f3
Not reproduced in: 2017.3.0a7, 2017.2.0b11, 2017.1.1p1, 5.6.3p3