Broken: 2.79, 2.80, 2.81 HEAD (8c9e6f123a2).
Short description of error
Navigation Mode Scale Is Broken - it should never be calculated from the vector zero.
Exact steps for others to reproduce the error
- Set Blender Navigation to Scale
- Try to press Alt + click and drag in viewport to make it zooming (or click and hold the "zoom" icon in the viewport).
- Try to cross the mouse arrow in the vector zero (i.e., cross the mouse around the middle of the viewport).
- As you can see the tool start to work weirdly inverting the zooming as soon you cross the scene vector zero.
Note: The other zoom modes (e.g., dolly) also present a strange behaviour when zooming horizontally. But the zoom seems to reset when going over the origin regardless of the mouse direction.