[Bullet] Bullet Ignores RigidBody Damping Settings When They Are Zero

[Wolfe2x7]

Godot version: 3.2.3 Standard x64
OS/device including version: Windows 7 Pro x64
Issue description:
In the Bullet physics engine, setting the linear or angular damping of a RigidBody to zero has no effect; the engine will ignore the setting and use the default value in the project settings. The only way to get zero damping is by setting the default value(s) to zero in the project settings.

The Godot physics engine appears to behave as expected. Zero damping for a specific object is zero damping.

Steps to reproduce:
Set a RigidBody into motion with the RigidBody's damping values at the default, and again at zero. Easier to see with project settings that make the damping obvious, of course.

Minimal reproduction project:

[Wolfe2x7]

Sorry, I've tried to include a minimal reproduction project but GitHub doesn't seem to be working right on Waterfox all of a sudden? I can't preview a post, do formatting with the buttons, or even edit my post above. I thought I had attached the ZIP I made.

[Calinou]

cc @madmiraal

Sorry, I've tried to include a minimal reproduction project but GitHub doesn't seem to be working right on Waterfox all of a sudden?

As far as I know, Waterfox's rendering and JavaScript engines are still based on the one found in Firefox 56 (which is 25 versions behind the latest Firefox). I'd expect some websites to start breaking at this point.

[madmiraal]

We discussed #37880 yesterday, and agreed a way forward, which will including getting this fixed.
cc @pouleyKetchoupp

[Wolfe2x7]

@Calinou -- Thanks for the heads up; that explains some other hitches I've been experiencing. I've now found that it's known, there's a partial temporary fix, and they're working on it. Classic Theme Restorer may live in my add-ons for another day...

@madmiraal -- Thanks! I will move forward with zero damping in the project settings for now.