The merge_repo is never created automatically, so if you don't create it manually, the merge status will never be shown correctly when viewing a merge request.
use master please.
#713 see details
@vsizov Not true. The current still relies on tmp/merge_repo to be present to write a lock file: https://github.com/gitlabhq/gitlabhq/blob/master/lib/gitlab_merge.rb#L29
If tmp/merge_repo is not available no auto-merge status will be shown.
This is fixed properly in 21f3da2
FYI: small improvement 903f949