1 files changed, 37 insertions, 31 deletions
diff --git a/app/finders/groups_finder.rb b/app/finders/groups_finder.rb
index d3597ef0901..91cb0f228f0 100644
--- a/app/finders/groups_finder.rb
+++ b/app/finders/groups_finder.rb
@@ -1,38 +1,44 @@
 class GroupsFinder
-  def execute(current_user, options = {})
-    all_groups(current_user)
+  # Finds the groups available to the given user.
+  #
+  # current_user - The user to find the groups for.
+  #
+  # Returns an ActiveRecord::Relation.
+  def execute(current_user = nil)
+    if current_user
+      relation = groups_visible_to_user(current_user)
+    else
+      relation = public_groups
+    end
+
+    relation.order_id_desc
   end
 
   private
 
-  def all_groups(current_user)
-    if current_user
-      if current_user.authorized_groups.any?
-        # User has access to groups
-        #
-        # Return only:
-        #   groups with public projects
-        #   groups with internal projects
-        #   groups with joined projects
-        #
-        group_ids = Project.public_and_internal_only.pluck(:namespace_id) +
-          current_user.authorized_groups.pluck(:id)
-        Group.where(id: group_ids)
-      else
-        # User has no group membership
-        #
-        # Return only:
-        #   groups with public projects
-        #   groups with internal projects
-        #
-        Group.where(id: Project.public_and_internal_only.pluck(:namespace_id))
-      end
-    else
-      # Not authenticated
-      #
-      # Return only:
-      #   groups with public projects
-      Group.where(id: Project.public_only.pluck(:namespace_id))
-    end
+  # This method returns the groups "current_user" can see.
+  def groups_visible_to_user(current_user)
+    base = groups_for_projects(public_and_internal_projects)
+
+    union = Gitlab::SQL::Union.
+      new([base.select(:id), current_user.authorized_groups.select(:id)])
+
+    Group.where("namespaces.id IN (#{union.to_sql})")
+  end
+
+  def public_groups
+    groups_for_projects(public_projects)
+  end
+
+  def groups_for_projects(projects)
+    Group.public_and_given_groups(projects.select(:namespace_id))
+  end
+
+  def public_projects
+    Project.unscoped.public_only
+  end
+
+  def public_and_internal_projects
+    Project.unscoped.public_and_internal_only
   end
 end