Once your issue is filed, begin your fix by forking Filer and creating a new branch. You must create a new branch before you commit any code or submit a pull request. If your Issue was #123, create a branch named issue-123.

On your new branch, you can make as many commits as you need to. Don't worry if you make mistakes, or need to overwrite/undo something; just add more commits to fix the problems. If you need to add new test files, that's fine, or you might be able to add to an existing file. Also, do not merge any code into your branch. Leave that for the very end, when your fully reviewed and corrected pull request will (hopefully) get merged by a Filer maintainer.