To reproduce:

1. In a new project, create a cube
2. With the scene camera, navigate far away from the cube (with WASD, for example)
3. Press F to focus on the cube and immediately scroll the scroll wheel
4. Observe that the focus animation doesn't stop as soon as you scroll the wheel

Expected: the focus animations stops immediately after the scroll wheel is used as it does when the camera is zoomed out with a scroll wheel instead of moved with WASD

Reproduced in 2017.4.11f1, 2018.1.9f2, 2018.2.6f1, 2018.2.8f1, 2018.3.0b1