Texture Paint Fill: 3d depth sorting?

Texture Paint Fill: 3d depth sorting

When I use the FILL tool in the 3d window, it color-fills the whole Object’s mesh, rather than the disconnected objects.

(See jpg) In this image the eyeball is unconnected to the rest of the face, but using Fill in the 3D window/Texture Paint fills the entire mesh with that color. My expectation was that it would fill all connected faces.

Is there a setting that restricts FILL to connected faces?