Display the Authors and commit message for commits that cause a conflict

Question

I have two long-running branches dev, and a far future release called future . We create fixes for the supported release by branching from the tag that exhibits the bug, fix it, and then open pull-requests to the two branches. If there is a conflict in the 'future' branch, our developers are suppose to create a new branch, resolve the conflicts, and open another PR to future.

Unfortunately, our team is large enough that plenty of these second PRs haven't been made. I need to now figure out which exact commits caused conflicts. I can do this manually by running git blame on each conflicted file, and seeing the commits on each side of the ====== line, but that doesn't actually give me enough information, and I have to manually run git blame for every conflict and every file.

Is there an easier way? Ideally, I'd want something equivalent to:

Commit X: <coworker1> I updated something.
Commit Y: <coworker2> Something fixed.
Conflicts: 
   some/file/here
   a/different/file.

for every single conflict.

Though anything that just gives me the list of conflicting commits would be useful enough to warrant the bounty.

Answer 1

You could run git diff --diff-filter=U while merging to see diff output for all (and only) unmerged files. It's still with file content, but it's better than manually running a command for each file.

Answer 2

You can get pretty close very easily:

git ls-files -u | cut -f2- | uniq \
| while read conflicted; do
        echo @@@ conflicted file $conflicted touched in this merge by:
        git log HEAD...MERGE_HEAD --left-right --format='    %h %aN %s' -- "$conflicted"
done

and really, it's only the right-branch (the one being merged in) commit authors you care about -- the left-branch ones have already been merged, let whoever touched what you've already got sort it out.

Add --topo-order to the log command to list the commits for each branch together.