I just lost my works due to this problem. I working on something then I realized that I need to refactor the current commit before create a new commit for the current works. So I stash all of my current works with:
git stash -u
Then I start refactor the current commit. Once finished I amend the current commit with:
git commit --amend
Then I restore my stash with:
git stash pop
What I found is all changes have been restored EXCEPT untracked files. No any untracked files has been restored.