Multi-label filtering only works at the project level

Summary

The new feature for filtering on multiple labels is great! Unfortunately, in my experience, it only works at the project-level. At the group and site-wide levels, I'm only able to filter by a single label.

Steps to reproduce

  1. Create 2 labels (let's say, Status: In Progress and Type: Enhancement)
  2. Create 2 issues on the same project
  • Each issue should have only one of the above labels
  1. Go the project group's "issues" page
  2. Try to filter by multiple labels (you should only be able to filter by one)
  3. Be sad that you can only see 1 of the issues created

Expected behavior

I'd expect filtering by multiple labels at the group/site-wide levels would work in the same way as filtering at the project-level.

Screenshots

Interestingly, I could take the query param label_name from the URL, add it to group and site-wide issue pages, and I'd get the same results (albeit, w/o the graphics showing which labels I had selected).

Project Level (group: ta, project: infrastructure) gitlab-project-level-multi-label-filter

Group Level (group: ta) gitlab-group-level-multi-label-filter

Site-wide Level gitlab-site-level-multi-label-filter

Output of checks

Results of GitLab Application Check

sudo gitlab-rake gitlab:check SANITIZE=true

Checking GitLab Shell ...                     
                                              
GitLab Shell version >= 2.7.2 ? ... OK (2.7.2)
Repo base directory exists? ... yes           
Repo base directory is a symlink? ... no      
Repo base owned by git:git? ... yes           
Repo base access is drwxrws---? ... yes       
hooks directories in repos are links: ...     
1/1 ... ok                                    
16/3 ... ok                                   
54/4 ... ok                                   
...
5/618 ... ok                                                                                                                   
16/619 ... ok                                                                                                                  
8/620 ... ok                                                                                                                   
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check                                                                    
Check GitLab API access: OK                                                                                                    
Check directories and files:                                                                                                   
        /var/opt/gitlab/git-data/repositories: OK                                                                              
        /var/opt/gitlab/.ssh/authorized_keys: OK                                                                               
Test redis-cli executable: redis-cli 2.8.24                                                                                    
Send ping to redis server: PONG                                                                                                
gitlab-shell self-check successful                                                                                             
                                                                                                                               
Checking GitLab Shell ... Finished                                                                                             
                                                                                                                               
Checking Sidekiq ...                                                                                                           
                                                                                                                               
Running? ... yes                                                                                                               
Number of Sidekiq processes ... 1                                                                                              
                                                                                                                               
Checking Sidekiq ... Finished                                                                                                  
                                                                                                                               
Checking Reply by email ...                                                                                                    
                                                                                                                               
Reply by email is disabled in config/gitlab.yml                                                                                
                                                                                                                               
Checking Reply by email ... Finished                                                                                           
                                                                                                                               
Checking LDAP ...                                                                                                              
                                                                                                                               
LDAP is disabled in config/gitlab.yml                                                                                          
                                                                                                                               
Checking LDAP ... Finished                                                                                                     
                                                                                                                               
Checking GitLab ...                                                                                                            
                                                                                                                               
Git configured with autocrlf=input? ... yes                                                                                    
Database config exists? ... yes                                                                                                
All migrations up? ... yes                                                                                                     
Database contains orphaned GroupMembers? ... no                                                                                
GitLab config exists? ... yes                                                                                                  
GitLab config outdated? ... no                                                                                                 
Log directory writable? ... yes                                                                                                
Tmp directory writable? ... yes                                                                                                
Uploads directory setup correctly? ... no                                                                                      
  Try fixing it:                                                                                                               
  sudo chown -R git /var/opt/gitlab/gitlab-rails/uploads                                                                       
  sudo find /var/opt/gitlab/gitlab-rails/uploads -type f -exec chmod 0644 {} \;                                                
  sudo find /var/opt/gitlab/gitlab-rails/uploads -type d -not -path /var/opt/gitlab/gitlab-rails/uploads -exec chmod 0700 {} \;
  For more information see:                                                                                                    
  doc/install/installation.md in section "GitLab"                                                                              
  Please fix the error above and rerun the checks.                                                                             
Init script exists? ... skipped (omnibus-gitlab has no init script)                                                            
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)                                                        
projects have namespace: ...                                                                                                   
1/1 ... yes                                                                                                                    
16/3 ... yes                                                                                                                   
54/4 ... yes                                                                                                                   
54/5 ... yes                                                                                                                   
54/6 ... yes                                                                                                                   
...
8/620 ... yes                                      
Redis version >= 2.8.0? ... yes                    
Ruby version >= 2.1.0 ? ... yes (2.1.8)            
Your git bin path is "/opt/gitlab/embedded/bin/git"
Git version >= 2.7.3 ? ... yes (2.7.4)             
Active users: 44                                   
                                                   
Checking GitLab ... Finished

Results of GitLab Environment Info

sudo gitlab-rake gitlab:env:info

System information                                                            
System:         Ubuntu 14.04                                                  
Current User:   git                                                           
Using RVM:      no                                                            
Ruby Version:   2.1.8p440                                                     
Gem Version:    2.5.1                                                         
Bundler Version:1.10.6                                                        
Rake Version:   10.5.0                                                        
Sidekiq Version:4.0.1                                                         
                                                                              
GitLab information                                                            
Version:        8.7.0                                                         
Revision:       f2a3f70                                                       
Directory:      /opt/gitlab/embedded/service/gitlab-rails                     
DB Adapter:     postgresql                                                    
URL:            http://GIT_URL
HTTP Clone URL: http://GIT_URL.local/some-group/some-project.git
SSH Clone URL:  git@GIT_URL.local:some-group/some-project.git   
Using LDAP:     no                                                            
Using Omniauth: no                                                            
                                                                              
GitLab Shell                                                                  
Version:        2.7.2                                                         
Repositories:   /var/opt/gitlab/git-data/repositories                         
Hooks:          /opt/gitlab/embedded/service/gitlab-shell/hooks/              
Git:            /opt/gitlab/embedded/bin/git                                  

Possible fixes