Documentation says that envvars GIT_COMMITTER_NAME and GIT_COMMITTER_EMAIL formed from REMOTE_USER and REMOTE_ADDR, but doesn't mention that they are left alone if they have been set already. Referring to: https://github.com/git/git/blob/master/Documentation/git-http-backend.txt#L178
Source code says that they are set conditionally (referring to this part of the source): https://github.com/git/git/blob/master/http-backend.c#L335
And the (most recent) commit pertaining to this behavior explains the change: https://github.com/git/git/commit/e32a4581bcbf1cf43cd5069a0d19df07542d612a
I'm also for the possibility of custom implementations assigning those envvars, so could the documentation be changed to reflect that?