feature spec for #34252

https://gitlab.com/gitlab-org/gitlab-ce/issues/34252

spec/features/boards/boards_spec.rb

@@ -69,6 +69,7 @@ describe 'Issue Boards', :js do
     let!(:backlog)    { create(:label, project: project, name: 'Backlog') }
     let!(:closed)       { create(:label, project: project, name: 'Closed') }
     let!(:accepting)  { create(:label, project: project, name: 'Accepting Merge Requests') }
+    let!(:a_plus) { create(:label, project: project, name: 'A+') }
 
     let!(:list1) { create(:list, board: board, label: planning, position: 0) }
     let!(:list2) { create(:list, board: board, label: development, position: 1) }
@@ -83,6 +84,7 @@ describe 'Issue Boards', :js do
     let!(:issue7) { create(:labeled_issue, project: project, title: 'ggg', description: '777', labels: [development], relative_position: 2) }
     let!(:issue8) { create(:closed_issue, project: project, title: 'hhh', description: '888') }
     let!(:issue9) { create(:labeled_issue, project: project, title: 'iii', description: '999', labels: [planning, testing, bug, accepting], relative_position: 1) }
+    let!(:issue10) { create(:labeled_issue, project: project, title: 'issue +', description: 'A+ great issue', labels: [a_plus]) }
 
     before do
       visit project_board_path(project, board)
@@ -400,6 +402,15 @@ describe 'Issue Boards', :js do
         wait_for_empty_boards((3..4))
       end
 
+      it 'filters by label with encoded character' do
+        set_filter("label", a_plus.title)
+        click_filter_link(a_plus.title)
+        submit_filter
+
+        wait_for_board_cards(1, 1)
+        wait_for_empty_boards((2..4))
+      end
+
       it 'filters by label with space after reload' do
         set_filter("label", "\"#{accepting.title}")
         click_filter_link(accepting.title)