Preserve comment authors and assignees in issues and MR after a gitlab export/import

Not sure this issue should be a bug or a proposal.

Description

I am trying to move a gitlab project from one privately hosted gitlab server to another through the import/export functionality. Originated gitlab is in version : 10.0.4 and targeted gitlab is in version : 10.1.4. (According to the doc, export/import process is allowed)

Your documentation specifies that the following items should be exported

  • Project and wiki repositories
  • Project uploads
  • Project configuration including web hooks and services
  • Issues with comments, merge requests with diffs and comments, labels, milestones, snippets, and other project entities

After importing project, it appears that :

  • comments authors
  • merge requests assignees
  • issues assignees

become authored by me instead of the real author

Proposal

An email matching could be done to preserve integrity, as git does.

Use case

  1. Export a project from a hosted gitlab CE (version 10.0 to current) containing MR with comments or issues
  2. Ensure all users exists in the target gitlab, identified by their email addresses
  3. Import the project in the target hosted gitlab
  4. Find that all comments authors and MR assignees become authored by me

Feature checklist

Make sure these are completed before closing the issue, with a link to the relevant commit.