resolve: commit the changes after each item resolve (
issue3638)
At the moment the resolve command doesn't save progress during the resolve process. In example if you try to resolve 100 conflicting files and interrupt the process (e.g., you close the external merge tool) after resolving 50 files you'll end up with 100 unresolved conflicts. Saving the progress helps a lot with long going merges. It's easy to achieve same behavior with simple script that calls resolve command for each unresolved file but it makes sense to make such behavior a default