Replace single quotes with escaped single quotes and write spec to test multiple…

app/assets/javascripts/gl_dropdown.js

@@ -600,14 +600,15 @@
           selectedObject = this.renderedData[selectedIndex];
         }
       }
+      field = [];
       fieldName = typeof this.options.fieldName === 'function' ? this.options.fieldName(selectedObject) : this.options.fieldName;
       value = this.options.id ? this.options.id(selectedObject, el) : selectedObject.id;
       if (isInput) {
         field = $(this.el);
-      } else {
-        field = this.dropdown.parent().find("input[name='" + fieldName + "'][value='" + escape(value) + "']");
+      } else if(value) {
+        field = this.dropdown.parent().find("input[name='" + fieldName + "'][value='" + value.toString().replace(/'/g, '\\\'') + "']");
       }
-      if (el.hasClass(ACTIVE_CLASS)) {
+      if (field.length && el.hasClass(ACTIVE_CLASS)) {
         el.removeClass(ACTIVE_CLASS);
         if (isInput) {
           field.val('');
@@ -617,7 +618,7 @@
       } else if (el.hasClass(INDETERMINATE_CLASS)) {
         el.addClass(ACTIVE_CLASS);
         el.removeClass(INDETERMINATE_CLASS);
-        if (value == null) {
+        if (field.length && value == null) {
           field.remove();
         }
         if (!field.length && fieldName) {
@@ -630,7 +631,7 @@
             this.dropdown.parent().find("input[name='" + fieldName + "']").remove();
           }
         }
-        if (value == null) {
+        if (field.length && value == null) {
           field.remove();
         }
         // Toggle active class for the tick mark
@@ -638,7 +639,7 @@
         if (value != null) {
           if (!field.length && fieldName) {
             this.addInput(fieldName, value, selectedObject);
-          } else {
+          } else if (field.length) {
             field.val(value).trigger('change');
           }
         }

app/assets/javascripts/labels_select.js

@@ -166,7 +166,7 @@
                 instance.addInput(this.fieldName, label.id);
               }
             }
-            if ($form.find("input[type='hidden'][name='" + ($dropdown.data('fieldName')) + "'][value='" + escape(this.id(label)) + "']").length) {
+            if (this.id(label) && $form.find("input[type='hidden'][name='" + ($dropdown.data('fieldName')) + "'][value='" + this.id(label).toString().replace(/'/g, '\\\'') + "']").length) {
               selectedClass.push('is-active');
             }
             if ($dropdown.hasClass('js-multiselect') && removesAll) {

app/views/shared/issuable/_label_dropdown.html.haml

@@ -12,7 +12,7 @@
 - if params[:label_name].present?
   - if params[:label_name].respond_to?('any?')
     - params[:label_name].each do |label|
-      = hidden_field_tag "label_name[]", u(label), id: nil
+      = hidden_field_tag "label_name[]", label, id: nil
 .dropdown
   %button.dropdown-menu-toggle.js-label-select.js-multiselect{class: classes.join(' '), type: "button", data: dropdown_data}
     %span.dropdown-toggle-text

spec/features/issues/filter_issues_spec.rb

@@ -101,7 +101,7 @@ describe 'Filter issues', feature: true do
       expect(find('.js-label-select .dropdown-toggle-text')).to have_content('No Label')
     end
 
-    it 'filters by no label' do
+    it 'filters by a label' do
       find('.dropdown-menu-labels a', text: label.title).click
       page.within '.labels-filter' do
         expect(page).to have_content label.title
@@ -109,7 +109,7 @@ describe 'Filter issues', feature: true do
       expect(find('.js-label-select .dropdown-toggle-text')).to have_content(label.title)
     end
 
-    it 'filters by wont fix labels' do
+    it "filters by `won't fix` and another label" do
       find('.dropdown-menu-labels a', text: label.title).click
       page.within '.labels-filter' do
         expect(page).to have_content wontfix.title
@@ -117,6 +117,33 @@ describe 'Filter issues', feature: true do
       end
       expect(find('.js-label-select .dropdown-toggle-text')).to have_content(wontfix.title)
     end
+
+    it "filters by `won't fix` label followed by another label after page load" do
+      find('.dropdown-menu-labels a', text: wontfix.title).click
+      # Close label dropdown to load
+      find('body').click
+      expect(find('.filtered-labels')).to have_content(wontfix.title)
+
+      find('.js-label-select').click
+      wait_for_ajax
+      find('.dropdown-menu-labels a', text: label.title).click
+      # Close label dropdown to load
+      find('body').click
+      expect(find('.filtered-labels')).to have_content(label.title)
+
+      find('.js-label-select').click
+      wait_for_ajax
+      expect(find('.dropdown-menu-labels li', text: wontfix.title)).to have_css('.is-active')
+      expect(find('.dropdown-menu-labels li', text: label.title)).to have_css('.is-active')
+    end
+
+    it "selects and unselects `won't fix`" do
+      find('.dropdown-menu-labels a', text: wontfix.title).click
+      find('.dropdown-menu-labels a', text: wontfix.title).click
+      # Close label dropdown to load
+      find('body').click
+      expect(page).not_to have_css('.filtered-labels')
+    end
   end
 
   describe 'Filter issues for assignee and label from issues#index' do