Merge branch 'fix_empty_diff_case' into 'master'

Fix the case when diff is empty

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/150097



Merged-by: Lin Jen-Shin <jen-shin@gitlab.com>
Approved-by: Lin Jen-Shin <jen-shin@gitlab.com>
Co-authored-by: Alexandru Croitor <acroitor@gitlab.com>