Revert – Everything You'll Need to Know About Git

The Decision We All Face

Often you have one of two choices to make: push forward or roll back. Rolling back can often require you to revert changes made to the main branch.

Note

In case you are confused about revert and restore

This is different than git restore since we are not restoring a file to a previous commit, but instead we are commiting an inverted commit to the graph to effectively "remove" a commit.

If the commit is matter, git revert is the anti-matter

Git Revert

Reverting is simple. You just need to provide the commit(ish).

git revert <commitish>

Problem

Navigate to hello-git project and revert commit with log message E. Before removing it, check the contents of the commit via log with -p!

Solution

One thing we could do

➜  hello-git git:(trunk) git log -p --grep E
d53a122 (HEAD -> trunk) A + 10
ec6930d merged
f5b13f5 A + 8
6ec352b A + 7
c28b45c A + 5
2107110 A + 4
980fe2d yaya
99df23c small new line
fac2b82 A + 6
958f33f A + 3
b51e34a Merge branch 'trunk' of ../hello-git into trunk
a9cb358 no conflict
d8a2f95 Merge branch 'trunk' of ../hello-git into trunk
9648be0 A + 1
6eb0a42 A + 2
7282922 greatest changes
6849c67 upstream changes
42afc8d A remote change
b23e632 Y
2f43452 X
a665b08 E
79c5076 D
cb75afe A

Using log -p to look at the contents of E using --grep and -p

➜  hello-git git:(trunk) git log -p --grep E
commit a665b08996994c2e6620a6367b0ab524be221cb2
Author: ThePrimeagen <the.primeagen@gmail.com>
Date:   Sun Jan 28 10:56:37 2024 -0700

    E

diff --git a/README.md b/README.md
index b2f0a9a..d3045e2 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,3 @@
 A
 D
+E

Revert E

➜  hello-git git:(trunk) git revert a665b08
Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
error: could not revert a665b08... E
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git revert --continue".
hint: You can instead skip this commit with "git revert --skip".
hint: To abort and get back to the state before "git revert",
hint: run "git revert --abort".

HALT

Yes, conflicts can happen while reverting. Lets fix the conflict and finish this revert. Resloving them are a lot like rebase. figure out the code you want to keep and git revert --continue

➜  hello-git git:(trunk) git status
On branch trunk
You are currently reverting commit a665b08.
  (fix conflicts and run "git revert --continue")
  (use "git revert --skip" to skip this patch)
  (use "git revert --abort" to cancel the revert operation)

Unmerged paths:
  (use "git restore --staged <file>..." to unstage)
  (use "git add <file>..." to mark resolution)
        both modified:   README.md

no changes added to commit (use "git add" and/or "git commit -a")

git status shows the conflict is within README.md

A + 10
D
<<<<<<< HEAD
E
remote-change
downstream change
=======
>>>>>>> parent of a665b08 (E)

You can see right away that one change set contains

E
remote-change
downstream change

and the other contains nothing (our revert commit).

This means that git cannot tell how to revert this commit cleanly. We can help by keeping the contents below E but removing E

Problem

Finish the revert by fixing the conflict then use git revert --continue

use git log to see what the revert looks like

Solution

Merge conflict fixed

A + 10
D
remote-change
downstream change

Now, just like rebase, we have to git revert --continue

➜  hello-git git:(trunk) git add .
➜  hello-git git:(trunk) git revert --continue

Revert "E"

This reverts commit a665b08996994c2e6620a6367b0ab524be221cb2.

# Conflicts:
#    README.md

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
#
# On branch trunk
# You are currently reverting commit a665b08.
#
# Changes to be committed:
#    modified:   README.md
#

[trunk 7488b35] Revert "E"
 1 file changed, 1 deletion(-)

The commit message contains a nice message explaining exactly what commit you revert if any history looker decides to peruse the commits. A git log -p -1 shows the contents of the change too

commit 7488b357e64cf426eaa3390a6c406e2d10f63f40 (HEAD -> trunk)
Author: ThePrimeagen <ThePrimeagen@netflix.com>
Date:   Sun Feb 25 20:35:16 2024 -0700

    Revert "E"

    This reverts commit a665b08996994c2e6620a6367b0ab524be221cb2.

diff --git a/README.md b/README.md
index eb42c13..38dc2c1 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,4 @@
 A + 10
 D
-E
 remote-change
 downstream change

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