Check your version
This tutorial covers a topic in Drupal 8 which may or may not be the version you're using. We're keeping this tutorial online as a courtesy to users of Drupal 8, but we consider it archived.
In this video we will write our own patch to resolve an issue. We will take a screenshot of the issue before and after our patch, and upload the images and patch to the Drupal.org issue queue. This video follows the instructions in the Write a patch lesson on drupalladder.org.