Amending the message of Git commit made before a merge

You can try a git rebase --preserve-merges --interactive, with:

-p--preserve-merges

Instead of ignoring merges, try to recreate them.

The BUG section of the man page includes:

The todo list presented by --preserve-merges --interactive does not represent the topology of the revision graph.
Editing commits and rewording their commit messages should work fine, but attempts to reorder commits tend to produce counterintuitive results.

As jthill's comment describes (since -p will better preserve merges if conflict resolutions were recorder):

You can retroactively light rerere for a merge:

git config rerere.enabled truegit checkout $merge^1git merge $merge^2# for Windows: # git merge $merge^^2git read-tree --reset -u $mergegit commit -m-git checkout @{-1}

As noted by Soufiane Roui in the comments:

For Windows CMD users, use double caret to point for parents of the merge commit (e.g $merge^^1 instead of $merge^1).
Because the caret is considered as an escape character.

If and only if your colleagues have not pushed/pulled the changes ontop of f3e71c2 elsewhere, this will work. Otherwise I don't know what will happen. Changing the commit message is entirely cosmetic (== metadata change), given that you haven't pushed the commit you want to amend yet, but this could still result in history confusion if your colleagues have pushed/ pulled any part of the history which is atop it.

(thanks to Abizern for pointing out this failure-mode)