Allow merging projects together
In our organization we started with multiple separate projects but the code became more and more interconnected and now we are at the place that we have to release all projects together to make it clear which versions of them belong together. We decided that we should simply combine them together into one repo/project. But while we know how to do with git (we can have separate branches with separate origins we merge together) it is unclear how to migrate all issues and merge requests and other GitLab specific.
GitLab could provide along with move and delete projects also a way to merge them together. This could do a similar thing to importing a project from one GitLab instance to another, where all issues and merge requests are done under one user. Or it could be a proper merge keeping all references around, but then an issue of having to modify those references.
For moving issues, there is already a feature. So this could just make moving issues in bulk. For merge requests, if git repositories are merged so that there are simply parallel histories in it, then merge requests can still have original commits to reference.