To add to Boot's and Rabs excellent diagrams I would like to add my own to see if they can further underline the point they make.
In Fig. 1 we have a 3d representation of the system, on the perspective view we see from behind the sun and it seems to bear out that the moon is obscured.
however a slight shift of view proves this not to be the case
Here, still behind the sun we can now see the moon, the light from the outer edges will still reach it.
Finally.
From the moons point of view (and rendered) we can see that the small disc will never occult the sun, I, just for the hell of it placed the "dark disc all along the trajectory between the moon and sun and at no point was the sun obscured, case closed.