Add a way to get the unified diff file link between to branches before create merge request.
Description
Suppose we want to let someone download the unified diff file between two branches on GitLab without login. For now, we need to create a merge request first. Then get the diff link from "Download as" --> "Plain diff". However, can we add a new way to do this? Let user can get the unified diff file without creates MR.
In my case, some software were download through automatically generated links. It is hard to change those links without bringing any side effects. So I want to push the original implementation on GitLab, then create a new branch to add some modifications. When to build these softwares, download the unified diff file between two branches, then apply it. GitHub has a way to do this, but seems GitLab can't do this if without create a MR[1].
Proposal
When user/visitor comparing two branches, add a way to let them download the unified diff file. No need to create a MR first. GitHub can download the unified diff file by add .diff
suffix to the link of a pull request[2]. Inspired by this, GitHub seems have undocumented ways to download the unified diff file before create a pull request, that is: by add ".diff" or ".patch" suffix when comparing two branches. But GitLab didn't have that feature yet.