Captured mouse mode fails to capture mouse if it's outside the window on OSX

[jamie-pate]

Godot version:
3.2.3-stable

OS/device including version:

GPU: Intel Iris Pro OpenGL Engine
MacBookPro11,4
Quad-Core Intel Core i7
Intel Iris Pro VENDOR=0x80867 DEVICE=0x0d26
Mac OS X 10.15.6

Issue description:

This doesn't seem to work if the mouse cursor is over the dock when the mode is switched.

This is the code that I'm using to switch mouse modes:

func _set_active(value):
	active = value
	if $PlayerHead/Camera and value:
		$PlayerHead/Camera.current = value
	if value:
		var w: Node = world_mgr
		if w && w.has_method('get_arg'):
			if !w.get_arg('no-capture-mouse'):
				Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)
	else:
		Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)
		velocity = Vector3()

Steps to reproduce:

Download https://github.com/godotengine/godot-demo-projects/tree/d4bf89d3647097443bc4f3f8625d7564a1e80a01/3d/voxel
(or the attached .zip)
Open the project and run.
Click Start Game > Flat Grass and then press esc to open the menu and uncapture the mouse.
move the mouse down to the dock, and press esc again to re-capture the mouse.
Moving the mouse around and pressing arrow keys will still interact with the game, but when you click, it will click on the dock, because mouse button input is not captured?

See these video examples: https://streamable.com/y87gbv https://streamable.com/6i7fd9

Minimal reproduction project:

voxel.zip

[jamie-pate]

Workaround: call _fix_mouse_pos() after Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)

func _fix_mouse_pos():
	var tree = get_tree()
	if !tree:
		return
	var vp = tree.root
	if !vp:
		return
	var r = vp.get_visible_rect()
	var center = r.position + r.size * 0.5
	Input.warp_mouse_position(center)