I do a git pull/clone to some repository (mainly github ones). Sometimes after a few minutes the download crashes.
Here is a log.
remote: Counting object
If a pull hung up, it will not write any changes to your filesystem. This is because, if it would, your local repository would not be in a stable state.
There is no way to resume a pull/clone. So your only choice is to pull/clone again.
cd into the the main directory and run
git fetch
tested only on linux