instructions for removing commits

using-github/licenses.md

@@ -2,7 +2,7 @@
 layout: page
 title: Licensing
 parent: Using GitHub
-nav_order: 3
+nav_order: 4
 ---
 
 # Please, Please, Please, License Your Public GitHub Repositories

using-github/oh-no.md

@@ -0,0 +1,100 @@
+---
+layout: page
+title: Remove Commits
+parent: Using GitHub
+nav_order: 3
+---
+
+# Oh No! I committed solutions to a public repository and pushed to GitHub
+
+{: .warning}
+Be careful running the following commands. These are DESTRUCTIVE actions. 🌋
+
+## Remove all commits up to a certain point
+
+1. Find the last "good" commit hash by running:
+
+    ```
+    git log
+    ```
+
+    The output should have entries that look something like 
+
+    ```
+    commit a3cf8b9261a52a8c34098e5316278ce52e40a9b5
+    Author: Cal-CS-61A-Staff <cs61a@berkeley.edu>
+    Date:   Wed Mar 26 20:41:07 2025 +0000
+    ```
+
+2. Take the commit hash (above `a3cf8b9261a52a8c34098e5316278ce52e40a9b5`) and run the following locally:
+
+    ```
+    git reset --hard <hash>
+    ```
+
+    If you'd like to remove only the latest commit you can run the following instead:
+
+    ```
+    git reset --hard HEAD~1
+    ```
+
+3. Reflect your changes on the remote (public GitHub repo):
+
+    ```
+    git push origin HEAD --force
+    ```
+
+
+## Remove only specific commits 
+
+If you have a mix of "good" and "bad" commits, you'll want to interactively rebase. [Read more about rebasing.](https://www.atlassian.com/git/tutorials/rewriting-history/git-rebase)
+
+1. Identify the last commit hash after all all of the commits that you want to remove. The following commands may be useful for this:
+    ```
+    git log
+    git reflog
+    ```
+
+2. Start the interactive rebase using that hash:
+
+    ```
+    git rebase -i <hash>
+    ```
+
+3. Identify the commits that you want to remove and remove them in the edit screen.
+
+4. Resolve any conflicts.
+
+5. In the edit screen, save and exit.
+
+6. End the rebase by running:
+
+    ```
+    git rebase --continue
+    ```
+
+    If you messed up the rebase, here's your options:
+
+    * Abort the rebase without resetting HEAD to the original branch ("clean up" the rebase):
+
+        ```
+        git rebase --quit
+        ```
+
+    * Abort the rebase and reset HEAD to the original branch ("undo" the rebase):
+
+        ```
+        git rebase --abort
+        ```
+
+    * Continue with the rebase, but skip any commits that introduce a merge conflict (any commits with merge conflicts will not be in the git history after finishing the rebase):
+
+        ```
+        git rebase --skip
+        ```
+
+7. Reflect your changes on the remote (public GitHub repo):
+
+    ```
+    git push origin HEAD --force
+    ```