In a relatively recent update, Medics gained the ability to see how much ammo their heal target has for their currently selected weapon. This got me thinking about a medic healing/ubering a spy, because presumably they'll never display anything but full ammo. Or possibly even determining the identity of a spy because of their never-changing ammo count.
How much ammo does a medic's HUD display when healing an enemy spy disguised as a teammnate?