Remote Repositories and Synchronization - Git Recipes - page 352

To summarize, pushing updates the branches in the following way:

• In the local repository remote—the tracking branch is updated to the most
recent revision in the local tracking branch

• In the remote repository—the remote branch is updated to the most recent
revision in the local tracking branch

What happens if the push operation fails? If John executes $ git push origin
master in his repository as shown in Figure 10-9 , then the push is rejected with the
following message:

! [rejected] master -> master (fetch first)

and all the branches remain unchanged.

How pulling affects tracking branches

This time we are watching the change from John's perspective. Therefore johns-
repo is the local repository and shared-repo is the remote repository.
When you pull from the remote repository, then your local tracking branch and re-
mote tracking branch are updated. The remote branch remains unchanged. The first
case (without a merge) is depicted in Figures 10-16 and 10-17 . Figure 10-16 presents
the state just before a pull operation. The shared repository contains two revisions b1
and b2 that are not included in johns-repo . The pull operation brings these revi-
sions into johns-repo and updates the branches to the state shown in Figure 10-17 .