I have googling awhile, but can not find such information. Looks like git doesn't contain users and groups, only permissions. Am I right?
Does git contain information about used id / group id changes?
git
See the Content Limitations section of the git Wiki: git does not track file ownership, group membership, doesn't track most permission bits, ACLs, access and modification times, etc.Git tracks contents, and doesn't care much about pretty much everything else.