[zacharycohn]

IMO, that a manager would do this is pretty messed up. Even if YOU don't care, if this continues this manager will start to develop a reputation for taking credit from others. Then it will be much harder to recruit people internally to their team.

The best managers constantly are talking up people on THEIR team. They are responsible for creating an environment where people can excel. This makes them look good at a manager ("Everyone on my team consistently over-performs!"), everyone on the team looks great and it makes it easier for them to get recognition and promotions, and it makes it a very desirable team to work on which makes recruiting internally much easier.