Adding Git Merge commit will have duplicate files

Somehow, its possible to add Merge Commit into review now https://jira.atlassian.com/browse/FE-4004
However, the merge commit in branches other than master will produce duplicate files.

Steps to reproduce

1. Let's start with branch master
2. Create and checkout new branch ("feature")
3. Commit changes in 'test.txt" file - "Changes in feature"
4. Checkout master branch
5. Commit changes in 'test.txt' file - "Changes in master"
6. Checkout feature branch
7. Merge changes from master into feature branch
8. Fix the conflict and commit changes in 'test.txt' file - "Merge commit"
9. Add the commits from steps 3 and 8 (both in feature branch) into a review
   Duplicate files 'test.txt' appear in the review
10. Checkout master branch
11. Create a new brach ("feature2") only, no need to checkout
12. Commit changes in 'test2.txt" file - "Changes in master"
13. Checkout feature2 branch
14. Commit changes in 'test2.txt' file - "Changes in feature2"
15. Checkout master branch
16. Merge changes from feature2 into master branch
17. Fix the conflict and commit changes in 'test2.txt' file - "Merge commit 2"
18. Add the commits from steps 12 and 17 (both in master branch) into a review
    This does not produce duplicate file 'test2.txt'