Error when viewing registry

Zendesk issue: https://gitlab.zendesk.com/agent/tickets/26951

---

Our scenario is, gitlab-ci.yml with docker:1.9.1-dind and runner with "docker:1.9.1". The problem is, gitlab container registry view is not working when we use images based in docker:1.9.1-dind. Build, push and pull are OK.

Log:

Started GET "/group/project/container_registry" for 127.0.0.1 at 2016-06-13 11:22:02 -0300 
Processing by Projects::ContainerRegistryController#index as HTML 
Parameters: {"namespace_id"=>"group", "project_id"=>"project"} 
Completed 200 OK in 227ms (Views: 131.9ms | ActiveRecord: 27.9ms) 
Completed 500 Internal Server Error in 160ms (ActiveRecord: 8.2ms)

ActionView::Template::Error (undefined method `map' for nil:NilClass): 
3: = escape_once(tag.name) 
4: = clipboard_button(clipboard_text: "docker pull #{tag.path}") 
5: %td 
6: - if layer = tag.layers.first 
7: %span.has-tooltip{ title: "#{layer.revision}" } 
8: = layer.short_revision 
9: - else 
lib/container_registry/tag.rb:60:in `layers' 
app/views/projects/container_registry/_tag.html.haml:6:in `_app_views_projects_container_registry__tag_html_haml___3094128187760054848_162968540' 
app/views/projects/container_registry/index.html.haml:40:in `block in _app_views_projects_container_registry_index_html_haml__893847784878579801_163384480' 
app/views/projects/container_registry/index.html.haml:39:in `each' 
app/views/projects/container_registry/index.html.haml:39:in `_app_views_projects_container_registry_index_html_haml__893847784878579801_163384480' 
lib/gitlab/middleware/go.rb:16:in `call' 
lib/gitlab/middleware/readonly_geo.rb:29:in `call'

@ayufan @grzesiek @tmaczukin Have you encountered this issue, or do you have ideas what would cause this?