GitLab

Created by: mattseymour

I have been updating gitlab from 6.6 to 7.7 and whilst the process has been interesting I have come across the following problem with merge requests. All merge requests created in Gitlab 6.6 when migrated now result in a 500 error with the following trace.

Started GET "/account/project/merge_requests/59" for 127.0.0.1 at 2015-02-19 15:49:20 +0000
Processing by Projects::MergeRequestsController#show as HTML
  Parameters: {"project_id"=>"account/project", "id"=>"59"}
Completed 500 Internal Server Error in 63ms

Module::DelegationError (MergeRequest#commits delegated to merge_request_diff.commits, but
merge_request_diff is nil: #<MergeRequest id: 81, target_branch: "develop", source_branch: "develop",
source_project_id: 18, author_id: 6, assignee_id: nil, title: "Develop", created_at: "2015-01-09
17:44:55", updated_at: "2015-01-13 10:16:57", milestone_id: nil, state: "merged", merge_status:
"unchecked", target_project_id: 7, iid: 59, description: "", position: 0, locked_at: nil>):
  app/models/merge_request.rb:39:in `rescue in commits'
  app/models/merge_request.rb:39:in `commits'
  app/controllers/projects/merge_requests_controller.rb:195:in `validates_merge_request'

System information:

System information
System:     Ubuntu 12.04
Current User:   git
Using RVM:  no
Ruby Version:   2.1.4p265
Gem Version:    2.2.1
Bundler Version:1.5.3
Rake Version:   10.3.2
Sidekiq Version:2.17.8

GitLab information
Version:    7.7.2
Revision:   bd98290
Directory:  /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: postgresql
URL:        http://aserver
HTTP Clone URL: http://aserver/some-project.git
SSH Clone URL:  git@aserver:some-project.git
Using LDAP: no
Using Omniauth: no

GitLab Shell
Version:    2.4.2
Repositories:   /var/opt/gitlab/git-data/repositories
Hooks:      /opt/gitlab/embedded/service/gitlab-shell/hooks/
Git:        /opt/gitlab/embedded/bin/git