Merge branch 'ee-backport-issue_40654' into 'master'

[CE-Backport] Fix board filter when milestone is predefined

See merge request gitlab-org/gitlab-ce!15750

app/models/milestone.rb

@@ -84,6 +84,13 @@ class Milestone < ActiveRecord::Base
       else milestones.active
       end
     end
+
+    def predefined?(milestone)
+      milestone == Any ||
+        milestone == None ||
+        milestone == Upcoming ||
+        milestone == Started
+    end
   end
 
   def self.reference_prefix

app/services/boards/issues/list_service.rb

@@ -54,10 +54,11 @@ module Boards
       def without_board_labels(issues)
         return issues unless board_label_ids.any?
 
-        issues.where.not(
-          LabelLink.where("label_links.target_type = 'Issue' AND label_links.target_id = issues.id")
-                   .where(label_id: board_label_ids).limit(1).arel.exists
-        )
+        issues.where.not(issues_label_links.limit(1).arel.exists)
+      end
+
+      def issues_label_links
+        LabelLink.where("label_links.target_type = 'Issue' AND label_links.target_id = issues.id").where(label_id: board_label_ids)
       end
 
       def with_list_label(issues)