Correct redundant disable cop duplicated by department

lib/rubocop/cop/lint/redundant_cop_disable_directive.rb

@@ -185,7 +185,8 @@ def ignore_offense?(line_range)
         end
 
         def department_disabled?(cop, comment)
-          DirectiveComment.new(comment).in_directive_department?(cop)
+          directive = DirectiveComment.new(comment)
+          directive.in_directive_department?(cop) && !directive.overridden_by_department?(cop)
         end
 
         def directive_count(comment)

spec/rubocop/cop/lint/redundant_cop_disable_directive_spec.rb

@@ -547,6 +547,40 @@ def bar
         RUBY
       end
 
+      it 'removes cop duplicated by department' do
+        expect_offense(<<~RUBY)
+          # rubocop:disable Metrics, Metrics/ClassLength
+                                     ^^^^^^^^^^^^^^^^^^^ Unnecessary disabling of `Metrics/ClassLength`.
+          def bar
+            do_something
+          end
+        RUBY
+
+        expect_correction(<<~RUBY)
+          # rubocop:disable Metrics
+          def bar
+            do_something
+          end
+        RUBY
+      end
+
+      it 'removes cop duplicated by department on previous line' do
+        expect_offense(<<~RUBY)
+          # rubocop:disable Metrics
+          def bar
+            do_something # rubocop:disable Metrics/ClassLength
+                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Unnecessary disabling of `Metrics/ClassLength`.
+          end
+        RUBY
+
+        expect_correction(<<~RUBY)
+          # rubocop:disable Metrics
+          def bar
+            do_something
+          end
+        RUBY
+      end
+
       it 'does not remove correct department' do
         expect_no_offenses(<<~RUBY)
           # rubocop:disable Metrics