Fix issue drush-ops#1314: drush core-requirements does not output des…

…criptions in render arrays

commands/core/core.drush.inc

@@ -830,6 +830,9 @@ function drush_core_requirements() {
     if ($severity < $min_severity) {
       unset($requirements[$key]);
     }
+    if (isset($requirements[$key]['description'])) {
+      $requirements[$key]['description'] = drush_render($requirements[$key]['description']);
+    }
   }
   return $requirements;
 }
@@ -1360,7 +1363,7 @@ function drush_core_twig_compile() {
   foreach ($themes as $name => $theme) {
     $searchpaths[] = $theme->getPath();
   }
-  
+
   foreach ($searchpaths as $searchpath) {
     foreach ($file = drush_scan_directory($searchpath, '/\.html.twig/', array('tests')) as $file) {
       $relative = str_replace(drush_get_context('DRUSH_DRUPAL_ROOT'). '/', '', $file->filename);

commands/core/drupal/environment.inc

@@ -418,3 +418,21 @@ function drush_get_token($value = NULL) {
 function drush_url($path = NULL, array $options = array()) {
   return \Drupal\Core\Url::fromUserInput('/' . $path, $options)->toString();
 }
+
+/**
+ * Output a Drupal render array, object or string as plain text.
+ *
+ * @param string $data
+ *   Data to render.
+ *
+ * @return string
+ *   The plain-text representation of the input.
+ */
+function drush_render($data) {
+  if (is_array($data)) {
+    $data = \Drupal::service('renderer')->renderRoot($data);
+  }
+
+  $data = \Drupal\Core\Mail\MailFormatHelper::htmlToText($data);
+  return $data;
+}

commands/core/drupal/environment_7.inc

@@ -369,3 +369,21 @@ function drush_get_token($value = NULL) {
 function drush_url($path = NULL, array $options = array()) {
   return url($path, $options);
 }
+
+/**
+ * Output a Drupal render array, object or plain string as plain text.
+ *
+ * @param string $data
+ *   Data to render.
+ *
+ * @return string
+ *   The plain-text representation of the input.
+ */
+function drush_render($data) {
+  if (is_array($data)) {
+    $data = drupal_render($data);
+  }
+
+  $data = drupal_html_to_text();
+  return $data;
+}