#Recovering from Mistakes#
We all make goofs from time to time, but version control was designed to help us out when we goofed by remembering the history and giving us access to it.
###I started working in the wrong branch!### #####The setup##### Make a new branch adding_images
git branch adding_images
Make some changes, like adding  to the cheesecake recipe, showing off how delicious the end result is.
#####The problem#####
git branch reveals that we are still in our old branch making this change.
This is not good, as we are mixing together features.
Thankfully, since we didn't commit, the resolution is pretty easy. We'll use the stash, which acts like a stack of changes:
git stash
git checkout adding_images
git stash list //optional, but we can see what was stashed
git stash apply //applies the most recently stashed changes
Alternative fix In some cases, I've noticed newer versions of git are smart enough to do this for you if you simply switch branches:
git checkout adding_images
Try this first, and if git complains about uncommitted changes, go with the above solution.
#####To avoid this##### Make sure you checkout the branch after you make it:
git branch new_branch
git checkout new_branch
###I committed in the wrong branch!### #####The setup##### as before, but now execute
git commit -m "Added image of cheesecake"
after making the change(s).
#####The problem#####
git log --decorate shows us the problem in detail, with a commit in the wrong branch. Make a note of the first 5-10 letters/numbers in the sha hash, we'll need them in a bit.
Since we haven't pushed yet, no one else need know of our mistake. We'll simply copy the misplaced commit to the correct branch using the cherry-pick command and then delete the old commit.
git checkout adding_images
git cherry-pick [hash]
//if there are merge conflicts, you'll need to run git merge or git mergetool and then git cherry-pick --continue
git checkout old_branch
git reset --hard HEAD~1 //erases the last commit by resetting to the 2nd to last commit
git checkout adding_images
//back to work (on the right branch)
If you had the misfortune of committing multiple (e.g. 3) commits to the wrong branch, you'll do something similar:
git checkout adding_images
git cherry-pick [hash]~3..[hash]
//again, if there are merge conflicts, you'll need to run git merge or git mergetool and then git cherry-pick --continue
git checkout old_branch
git reset --hard HEAD~4 //erases the last 3 commits by resetting to the 4th to last commit
git checkout adding_images
//back to work (on the right branch)
#####To avoid this##### Make sure you checkout the branch after you make it:
git branch new_branch
git checkout new_branch
###I committed in the wrong branch and then pushed!###
#####The setup#####
as before, but the changes were pushed with git push.
#####The problem##### The previous two scenarios we were able to rewrite history a bit to make things appear as if they never went wrong.
However, because we shared our changes, we really should not change that public history, as other people may depend on it.
The best we can do is cherry-pick the commits into the proper branch and then make a set of commits that undoes the problem in the original branch.
git log --decorate shows us the commit in the wrong branch. Make a note of the first 5-10 letters/numbers in the sha hash, we'll need to know which commit to copy.
git checkout adding_images
git cherry-pick [hash]
//if there are merge conflicts, you'll need to run git merge or git mergetool and then git cherry-pick --continue
git checkout old_branch
git revert HEAD //reverts the last commit
git push //make your fixes public
git checkout adding_images
//back to work (on the right branch)
If you had the misfortune of committing multiple (e.g. 5) commits to the wrong branch, you'll do something similar:
git checkout adding_images
git cherry-pick [hash]~5..[hash]
//again, if there are merge conflicts, you'll need to run git merge or git mergetool and then git cherry-pick --continue
git checkout old_branch
git revert HEAD~5..HEAD //we need to list all 5 commits we are reverting. This will make a separate commit for each undid commit.
git push //make your fixes public
git checkout adding_images
//back to work (on the right branch)
#####To avoid this##### Make sure you checkout the branch after you make it:
git branch new_branch
git checkout new_branch