Documentation: Update Lesson2.md

Update Lesson2.md to include information about updating a commit after
it has been pushed to the remote repository.

Change-Id: Iebf86113b13d859d9c9e3db51e22ea44cb1144f6
Signed-off-by: Evelyn Huang <evhuang@google.com>
Reviewed-on: https://review.coreboot.org/20948
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

1 files changed, 28 insertions, 1 deletions

diff --git a/Documentation/Lesson2.md b/Documentation/Lesson2.md
index 55d81881ca..0263cedf4e 100644
--- a/Documentation/Lesson2.md
+++ b/Documentation/Lesson2.md
@@ -251,4 +251,31 @@ preferences. If you wish to do so, look at the "All configs for .bashrc" section
 on https://github.com/magicmonty/bash-git-prompt. Listed in that section are
 various lines that you can copy, uncomment and add to your .bashrc file to
 change the configurations. Example configurations include avoid fetching remote
-status, and supporting versions of Git older than 1.7.10.
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+status, and supporting versions of Git older than 1.7.10.
+
+## Appendix: Miscellaneous Advice
+
+### Updating a commit after running git push:
+
+Suppose you would like to update a commit that has already been pushed to the
+remote repository. If the commit you wish to update is the most recent
+commit you have made, after making your desired changes, stage the files
+(either using git add or in git cola), and amend the commit. To do so,
+if you are using the command line, run "git commit --amend." If you are
+using git cola, click on the gear icon located on the upper left side under
+**Commit** and select **Amend Last Commit** in the drop down menu. Then, stage
+the files you have changed, commit the changes, and run git push to push the
+changes to the remote repository. Your change should be reflected in Gerrit as
+a new patch set.
+
+If, however, the commit you wish to update is not the most recent commit you
+have made, you will first need to checkout that commit. To do so, find the
+URL of the commit on <https://review.coreboot.org> and go to that page; if
+the commit is one that you previously pushed, it can be found by selecting
+**My** and then **Changes** in the upper left corner. To checkout this commit,
+in the upper right corner, click on **Download**, and copy the command listed
+next to checkout by clicking **Copy to clipboard**. Then, run the copied
+command in your coreboot repository. Now, the last commit should be the most
+recent commit to that patch; to update it, make your desired changes, stage
+the files, then amend and push the commit using the instructions in the above
+paragraph.
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