Modifying the History - Git Recipes - page 287

The command $ git revert [REVISION] creates a new revision that reverts
the changes introduced by [REVISION] . The additional parameter --no-edit sets
the comment of a new revision to Revert "..." . This is the only way to undo the
revision that was already included in the public history of your project.
8-9. Reverting merge commit revisions
Problem
You work in your project using two branches: master and feature . The branches
diverged and you decided to merge feature branch into the master branch. When
you completed merging the feature branch was deleted.
After some time you realized that feature branch introduced a number of bugs
and serious problems. Therefore you want to revert the merge of branch feature into
the master branch.
The transformation you want to achieve is shown in Figure 8-9 .
Figure 8-9 . Reverting a merge commit
Solution