Issue #3019706 by hchonov, alexpott, sheanhoxie, jibran, dawehner: Functional JS Tests are broken if XDEBUG_CONFIG is set as an env variable

(cherry picked from commit 32dfb62)

Author: alexpott

tests/Drupal/Tests/BrowserTestBase.php

@@ -238,19 +238,23 @@ protected function initMink() {
       'hidden_field_selector' => new HiddenFieldSelector(),
     ]);
     $session = new Session($driver, $selectors_handler);
-    $cookies = $this->extractCookiesFromRequest(\Drupal::request());
-    foreach ($cookies as $cookie_name => $values) {
-      foreach ($values as $value) {
-        $session->setCookie($cookie_name, $value);
-      }
-    }
     $this->mink = new Mink();
     $this->mink->registerSession('default', $session);
     $this->mink->setDefaultSessionName('default');
     $this->registerSessions();
 
     $this->initFrontPage();
 
+    // Copies cookies from the current environment, for example, XDEBUG_SESSION
+    // in order to support Xdebug.
+    // @see BrowserTestBase::initFrontPage()
+    $cookies = $this->extractCookiesFromRequest(\Drupal::request());
+    foreach ($cookies as $cookie_name => $values) {
+      foreach ($values as $value) {
+        $session->setCookie($cookie_name, $value);
+      }
+    }
+
     return $session;
   }