Category "merge-request"

GitLab - Lines that have not been changed are marked in green

What does that mean? And how do I get rid of the highlighting? Lines 1-12 have not changed but are highlighted in green. <- Weird Lines 13-15 have not change

Set default reviewers for merge request in GitLab

How I can set default reviewers in GitLab Premium? In Settings → General I have only Merge request (MR) approvals, not reviewers.