Issue #2215473 by Lendude, speely, pjonckiere: Filter description not visible in exposed form

core/modules/views/src/Tests/Plugin/ExposedFormTest.php

@@ -137,6 +137,9 @@ public function testExposedFormRender() {
 
     $expected_action = _url($view->display_handler->getUrl());
     $this->assertFieldByXPath('//form/@action', $expected_action, 'The expected value for the action attribute was found.');
+    // Make sure the description is shown.
+    $result = $this->xpath('//form//div[contains(@id, :id) and normalize-space(text())=:description]', array(':id' => 'edit-type--description', ':description' => t('Exposed description')));
+    $this->assertEqual(count($result), 1, 'Filter description was found.');
   }
 
   /**

core/modules/views/tests/modules/views_test_config/test_views/views.view.test_exposed_form_buttons.yml

@@ -29,6 +29,7 @@ display:
             label: 'Content: Type'
             operator_id: type_op
             reduce: false
+            description: 'Exposed description'
           exposed: true
           field: type
           id: type

core/modules/views/views.theme.inc

@@ -1014,6 +1014,9 @@ function template_preprocess_views_exposed_form(&$variables) {
     if (!empty($info['label'])) {
       $form[$info['value']]['#title'] = $info['label'];
     }
+    if (!empty($info['description'])) {
+      $form[$info['value']]['#description'] = $info['description'];
+    }
   }
 }