diff --git a/core/modules/block/src/Controller/BlockLibraryController.php b/core/modules/block/src/Controller/BlockLibraryController.php
index 69d18f1..eb176d8 100644
--- a/core/modules/block/src/Controller/BlockLibraryController.php
+++ b/core/modules/block/src/Controller/BlockLibraryController.php
@@ -8,7 +8,6 @@
 use Drupal\Core\EventSubscriber\MainContentViewSubscriber;
 use Drupal\Core\Menu\LocalActionManagerInterface;
 use Drupal\Core\Plugin\Context\LazyContextRepository;
-use Drupal\Core\Routing\RedirectDestinationInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -48,13 +47,6 @@ class BlockLibraryController extends ControllerBase {
   protected $localActionManager;
 
   /**
-   * The redirect destination.
-   *
-   * @var \Drupal\Core\Routing\RedirectDestinationInterface
-   */
-  protected $redirectDestination;
-
-  /**
    * Constructs a BlockLibraryController object.
    *
    * @param \Drupal\Core\Block\BlockManagerInterface $block_manager
@@ -65,15 +57,12 @@ class BlockLibraryController extends ControllerBase {
    *   The current route match.
    * @param \Drupal\Core\Menu\LocalActionManagerInterface $local_action_manager
    *   The local action manager.
-   * @param \Drupal\Core\Routing\RedirectDestinationInterface $redirect_destination
-   *   The redirect destination.
    */
-  public function __construct(BlockManagerInterface $block_manager, LazyContextRepository $context_repository, RouteMatchInterface $route_match, LocalActionManagerInterface $local_action_manager, RedirectDestinationInterface $redirect_destination) {
+  public function __construct(BlockManagerInterface $block_manager, LazyContextRepository $context_repository, RouteMatchInterface $route_match, LocalActionManagerInterface $local_action_manager) {
     $this->blockManager = $block_manager;
     $this->routeMatch = $route_match;
     $this->localActionManager = $local_action_manager;
     $this->contextRepository = $context_repository;
-    $this->redirectDestination = $redirect_destination;
   }
 
   /**
@@ -84,8 +73,7 @@ public static function create(ContainerInterface $container) {
       $container->get('plugin.manager.block'),
       $container->get('context.repository'),
       $container->get('current_route_match'),
-      $container->get('plugin.manager.menu.local_action'),
-      $container->get('redirect.destination')
+      $container->get('plugin.manager.menu.local_action')
     );
   }
 
@@ -144,10 +132,6 @@ public function listBlocks(Request $request, $theme) {
       if ($region) {
         $links['add']['query']['region'] = $region;
       }
-      $destination = $this->redirectDestination->get();
-      if ($destination) {
-        $links['add']['query']['destination'] = $destination;
-      }
       $row['operations']['data'] = [
         '#type' => 'operations',
         '#links' => $links,
diff --git a/core/modules/block/src/Tests/BlockTest.php b/core/modules/block/src/Tests/BlockTest.php
index 039aa64..40db579 100644
--- a/core/modules/block/src/Tests/BlockTest.php
+++ b/core/modules/block/src/Tests/BlockTest.php
@@ -4,7 +4,6 @@
 
 use Drupal\Component\Utility\Html;
 use Drupal\block\Entity\Block;
-use Drupal\Core\Url;
 use Drupal\user\Entity\Role;
 use Drupal\user\RoleInterface;
 
@@ -129,49 +128,6 @@ function testBlockVisibilityListedEmpty() {
   }
 
   /**
-   * Tests adding a block from the library page with a destination query string.
-   */
-  public function testAddBlockFromLibrary() {
-    $default_theme = $this->config('system.theme')->get('default');
-    $help_url = Url::fromRoute('help.page', ['name' => 'block']);
-    // Set up the request so we land on the block help page after creation.
-    $options = [
-      'query' => [
-        'region' => 'sidebar_first',
-        'destination' => $help_url->toString(),
-      ],
-    ];
-    $this->drupalGet(Url::fromRoute('block.admin_library', ['theme' => $default_theme], $options));
-
-    $block_name = 'system_powered_by_block';
-    $add_url = Url::fromRoute('block.admin_add', ['plugin_id' => $block_name, 'theme' => $default_theme]);
-    $links = $this->xpath('//a[contains(@href, :href)]', [':href' => $add_url->toString()]);
-    $this->assertEqual(1, count($links), 'Found one matching link');
-
-    list($path, $query_string) = explode('?', $links[0]['href'], 2);
-    parse_str($query_string, $query_parts);
-    $this->assertEqual(t('Place block'), (string) $links[0]);
-    $this->assertEqual($help_url->toString(), $query_parts['destination'], 'Expected destination query string is in href');
-
-    // Create a random title for the block.
-    $title = $this->randomMachineName(8);
-    $block_id = strtolower($this->randomMachineName(8));
-    $edit = [
-      'id' => $block_id,
-      'settings[label]' => $title,
-    ];
-    // Create the block using the link parsed from the library page.
-    $this->drupalPostForm($this->getAbsoluteUrl($links[0]['href']), $edit, t('Save block'));
-    // Verify that we are redirected according to the original request.
-    $this->assertUrl($help_url);
-
-    // Ensure that the block was created.
-    /** @var \Drupal\block\BlockInterface $block */
-    $block = Block::load($block_id);
-    $this->assertEqual($title, $block->label(), 'Found the block with expected title.');
-  }
-
-  /**
    * Test configuring and moving a module-define block to specific regions.
    */
   function testBlock() {
diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index d119f7f..de7e2aa 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -122,22 +122,22 @@ function _simpletest_format_summary_line($summary) {
  *   The test ID.
  */
 function simpletest_run_tests($test_list) {
-  $test_id = db_insert('simpletest_test_id')
-    ->useDefaults(array('test_id'))
-    ->execute();
-
-  if (!empty($test_list['phpunit'])) {
-    $phpunit_results = simpletest_run_phpunit_tests($test_id, $test_list['phpunit']);
-    simpletest_process_phpunit_results($phpunit_results);
+  // We used to separate PHPUnit and Simpletest tests for a performance
+  // optimization. In order to support backwards compatibility check if these
+  // keys are set and create a single test list.
+  // @todo https://www.drupal.org/node/2748967 Remove BC support in Drupal 9.
+  if (isset($test_list['simpletest'])) {
+    $test_list = array_merge($test_list, $test_list['simpletest']);
+    unset($test_list['simpletest']);
   }
-
-  // Early return if there are no further tests to run.
-  if (empty($test_list['simpletest'])) {
-    return $test_id;
+  if (isset($test_list['phpunit'])) {
+    $test_list = array_merge($test_list, $test_list['phpunit']);
+    unset($test_list['phpunit']);
   }
 
-  // Continue with SimpleTests only.
-  $test_list = $test_list['simpletest'];
+  $test_id = db_insert('simpletest_test_id')
+    ->useDefaults(array('test_id'))
+    ->execute();
 
   // Clear out the previous verbose files.
   file_unmanaged_delete_recursive('public://simpletest/verbose');
@@ -190,7 +190,7 @@ function simpletest_run_phpunit_tests($test_id, array $unescaped_test_classnames
     // Something broke during the execution of phpunit.
     // Return an error record of all failed classes.
     $rows[] = [
-      'test_id' => '1',
+      'test_id' => $test_id,
       'test_class' => implode(",", $unescaped_test_classnames),
       'status' => 'fail',
       'message' => 'PHPunit Test failed to complete',
@@ -224,6 +224,48 @@ function simpletest_process_phpunit_results($phpunit_results) {
 }
 
 /**
+ * Maps phpunit results to a data structure for batch messages and run-tests.sh.
+ *
+ * @param array $results
+ *   The output from simpletest_run_phpunit_tests().
+ *
+ * @return array
+ *   The test result summary. A row per test class.
+ */
+function simpletest_summarise_phpunit_result($results) {
+  $summaries = [];
+  foreach ($results as $result) {
+    if (!isset($summaries[$result['test_class']])) {
+      $summaries[$result['test_class']] = array(
+        '#pass' => 0,
+        '#fail' => 0,
+        '#exception' => 0,
+        '#debug' => 0,
+      );
+    }
+
+    switch ($result['status']) {
+      case 'pass':
+        $summaries[$result['test_class']]['#pass']++;
+        break;
+
+      case 'fail':
+        $summaries[$result['test_class']]['#fail']++;
+        break;
+
+      case 'exception':
+        $summaries[$result['test_class']]['#exception']++;
+        break;
+
+      case 'debug':
+        $summaries[$result['test_class']]['#debug']++;
+        break;
+    }
+  }
+  return $summaries;
+}
+
+/**
  * Returns the path to use for PHPUnit's --log-junit option.
  *
  * @param $test_id
@@ -262,9 +304,18 @@ function simpletest_phpunit_configuration_filepath() {
  *   The results as returned by exec().
  */
 function simpletest_phpunit_run_command(array $unescaped_test_classnames, $phpunit_file, &$status = NULL) {
+  global $base_url;
   // Setup an environment variable containing the database connection so that
   // functional tests can connect to the database.
   putenv('SIMPLETEST_DB=' . Database::getConnectionInfoAsUrl());
+
+  // Setup an environment variable containing the base URL, if it is available.
+  // This allows functional tests to browse the site under test. When running
+  // tests via CLI, core/phpunit.xml.dist or core/scripts/run-tests.sh can set
+  // this variable.
+  if ($base_url) {
+    putenv('SIMPLETEST_BASE_URL=' . $base_url);
+  }
   $phpunit_bin = simpletest_phpunit_command();
 
   $command = array(
@@ -302,6 +353,9 @@ function simpletest_phpunit_run_command(array $unescaped_test_classnames, $phpun
 
   chdir($old_cwd);
   putenv('SIMPLETEST_DB=');
+  if ($base_url) {
+    putenv('SIMPLETEST_BASE_URL=');
+  }
   return $ret;
 }
 
@@ -352,15 +406,21 @@ function _simpletest_batch_operation($test_list_init, $test_id, &$context) {
 
   // Perform the next test.
   $test_class = array_shift($test_list);
-  $test = new $test_class($test_id);
-  $test->run();
+  if (is_subclass_of($test_class, \PHPUnit_Framework_TestCase::class)) {
+    $phpunit_results = simpletest_run_phpunit_tests($test_id, [$test_class]);
+    simpletest_process_phpunit_results($phpunit_results);
+    $test_results[$test_class] = simpletest_summarise_phpunit_result($phpunit_results)[$test_class];
+  }
+  else {
+    $test = new $test_class($test_id);
+    $test->run();
+    \Drupal::moduleHandler()->invokeAll('test_finished', array($test->results));
+    $test_results[$test_class] = $test->results;
+  }
   $size = count($test_list);
   $info = TestDiscovery::getTestInfo($test_class);
 
-  \Drupal::moduleHandler()->invokeAll('test_finished', array($test->results));
-
   // Gather results and compose the report.
-  $test_results[$test_class] = $test->results;
   foreach ($test_results[$test_class] as $key => $value) {
     $test_results[$key] += $value;
   }
diff --git a/core/modules/simpletest/src/Form/SimpletestTestForm.php b/core/modules/simpletest/src/Form/SimpletestTestForm.php
index 1c58efe..8ad5fe2 100644
--- a/core/modules/simpletest/src/Form/SimpletestTestForm.php
+++ b/core/modules/simpletest/src/Form/SimpletestTestForm.php
@@ -199,7 +199,6 @@ public function buildForm(array $form, FormStateInterface $form_state) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
-    global $base_url;
     // Test discovery does not run upon form submission.
     simpletest_classloader_register();
 
@@ -217,20 +216,8 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
       $form_state->setValue('tests', $user_input['tests']);
     }
 
-    $tests_list = array();
-    foreach ($form_state->getValue('tests') as $class_name => $value) {
-      if ($value === $class_name) {
-        if (is_subclass_of($class_name, 'PHPUnit_Framework_TestCase')) {
-          $test_type = 'phpunit';
-        }
-        else {
-          $test_type = 'simpletest';
-        }
-        $tests_list[$test_type][] = $class_name;
-      }
-    }
+    $tests_list = array_filter($form_state->getValue('tests'));
     if (!empty($tests_list)) {
-      putenv('SIMPLETEST_BASE_URL=' . $base_url);
       $test_id = simpletest_run_tests($tests_list, 'drupal');
       $form_state->setRedirect(
         'simpletest.result_form',
diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index df61328..c0afeb9 100755
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -690,36 +690,7 @@ function simpletest_script_run_phpunit($test_id, $class) {
 
   // Map phpunit results to a data structure we can pass to
   // _simpletest_format_summary_line.
-  $summaries = array();
-  foreach ($results as $result) {
-    if (!isset($summaries[$result['test_class']])) {
-      $summaries[$result['test_class']] = array(
-        '#pass' => 0,
-        '#fail' => 0,
-        '#exception' => 0,
-        '#debug' => 0,
-      );
-    }
-
-    switch ($result['status']) {
-      case 'pass':
-        $summaries[$result['test_class']]['#pass']++;
-        break;
-
-      case 'fail':
-        $summaries[$result['test_class']]['#fail']++;
-        break;
-
-      case 'exception':
-        $summaries[$result['test_class']]['#exception']++;
-        break;
-
-      case 'debug':
-        $summaries[$result['test_class']]['#debug']++;
-        break;
-    }
-  }
-
+  $summaries = simpletest_summarise_phpunit_result($results);
   foreach ($summaries as $class => $summary) {
     simpletest_script_reporter_display_summary($class, $summary);
   }