Want to revert a commit, however, get error message from git

[Romel Evans]

Receive the following error when I try to revert a commit:

git -c diff.mnemonicprefix=false -c core.quotepath=false -c credential.helper=manager-st revert --no-edit cc158e3f4f17dd49ef0c75ecd7f9c449e52307f8

error: commit cc158e3f4f17dd49ef0c75ecd7f9c449e52307f8 is a merge but no -m option was given.

fatal: revert failed

The reason for this revert attempt is that I merged the wrong branch into the current branch.  So before the revert, I reset (In Source Tree) a few of the files back to their previous commit, and discarded all of the items from my working copy, however, this didn't cleanup history, so I tried reverting the commit, but received the above error.  

Is there a way that I can clean up the history or revert the changes back to what they were originally?

[Romel Evans]

I had to create a custom Action that then I was able to apply on a commit.  The action was Git revert -n -m 1 $SHA.  I was not able to get rid of the history though.  So I ended up creating a tag (using a new name) for the last good commit for that branch and pushed it.  This was Followed by creating a new branch off the branch I just tagged, and gave it a differnt name, and finally closed the original branch and started using the new branch.

[minnsey]

Hi

I'm afraid SourceTree fro Windows does not support the '-m' option for reverting a merge. You will need to run that manually form the Terminal, see https://git-scm.com/docs/git-revert