Sprout Video
This lesson takes a look at applying a patch from Drupal.org to your local copy of a module or Drupal core using Git. Afterwards we'll look at how you can create your own patches, using git diff and git format-patch, in order to contribute code back to Drupal or any of the module's on Drupal.org. You can see a full Git workflow using GitHub in the lesson Git Workflow: Putting It All Together.
Additional resources
Git Best Practices: Upgrading the Patch Process article
Applying a patch in a feature branch