Does shooting reveal other friendly positions?

Supposedly shooting "makes bushes invisible in 15m radius" (or so the help says). Does it mean, that if I, as a scout (lots of camo bonuses), sit hidden in a bush, then an ally drives right over and shoots at enemy I spotted, my position would be revealed to enemies, or can I sit safely next to a shooting heavy and wait as slugs fly over my head?

Others shooting from bush does not reveal you tank sitting in the same bushes. The reason for bushes within 15m becoming "invisible" is to simulate gun flash when you shoot, making you lot easier to spot. As long as you dont shoot, the bushes will keep on camouflaging you, even if others are shooting near the same bush. This is quite easily testable with a tank with a commander with Sixth Sense perk.

Word of caution though, you can still get shot at even if they don't see you. Artillery is still a big threat. As well as that, the shots that miss the visible team mate can hit you or, depending on your position, you can be in the line of fire and accidentally get shot at. In the worst case, your team mate can hide "behind" you on purpose and shoot using you as invisible cover against the enemy. I've had this happen to me a few times so I know...