diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index c067328..409a997 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -146,10 +146,10 @@ function install_state_defaults() {
     // The last task that was completed during the previous installation
     // request.
     'completed_task' => NULL,
-    // TRUE when there is a valid database connection.
-    'database_verified' => FALSE,
     // TRUE when there are valid config directories.
     'config_verified' => FALSE,
+    // TRUE when there is a valid database connection.
+    'database_verified' => FALSE,
     // TRUE when a valid settings.php exists (containing both database
     // connection information and config directory names).
     'settings_verified' => FALSE,
@@ -271,19 +271,21 @@ function install_begin_request(&$install_state) {
   // This must go after drupal_bootstrap(), which unsets globals!
   global $conf;
 
-  require_once DRUPAL_ROOT . '/core/modules/system/system.install';
-  require_once DRUPAL_ROOT . '/core/includes/ajax.inc';
+  // Load include files containing procedural service helpers.
   require_once DRUPAL_ROOT . '/core/includes/cache.inc';
-  require_once DRUPAL_ROOT . '/core/includes/common.inc';
   require_once DRUPAL_ROOT . '/core/includes/database.inc';
+
+  // Required for module_list() override in early installer environment.
   require_once DRUPAL_ROOT . '/core/includes/file.inc';
-  require_once DRUPAL_ROOT . '/core/includes/form.inc';
+  require_once DRUPAL_ROOT . '/core/includes/module.inc';
+
+  // Required for various installer operations.
   require_once DRUPAL_ROOT . '/core/includes/install.inc';
-  require_once DRUPAL_ROOT . '/core/includes/schema.inc';
-  require_once DRUPAL_ROOT . '/' . variable_get('path_inc', 'core/includes/path.inc');
-  include_once DRUPAL_ROOT . '/core/includes/module.inc';
-  include_once DRUPAL_ROOT . '/core/includes/session.inc';
-  require_once DRUPAL_ROOT . '/core/includes/entity.inc';
+
+  // Required for running install tasks.
+  require_once DRUPAL_ROOT . '/core/includes/form.inc';
+  require_once DRUPAL_ROOT . '/core/includes/ajax.inc';
+  require_once DRUPAL_ROOT . '/core/includes/batch.inc';
 
   // Determine bootstrap status.
   if (!empty($install_state['parameters']['bootstrap'])) {
@@ -338,6 +340,7 @@ function install_begin_request(&$install_state) {
   // install System module as well as all the rest of the system in a full
   // environment.
   else {
+    require_once DRUPAL_ROOT . '/core/includes/common.inc';
     // DRUPAL_BOOTSTRAP_SESSION is incompatible with the installer, as it tries
     // to read and write sessions before the {users} table has been installed.
     // Therefore, the install_base_system() task needs a custom bootstrap that
@@ -506,7 +509,6 @@ function install_run_task($task, &$install_state) {
     // If we are in the middle of processing this batch, keep sending back
     // any output from the batch process, until the task is complete.
     elseif ($current_batch == $function) {
-      include_once DRUPAL_ROOT . '/core/includes/batch.inc';
       $output = _batch_page();
       // Because Batch API now returns a JSON response for intermediary steps,
       // but the installer doesn't handle Response objects yet, just send the
@@ -853,16 +855,9 @@ function install_verify_requirements(&$install_state) {
  * Install task: Installs the System module schema.
  */
 function install_system_schema(&$install_state) {
-  // Create base system tables if they do not exist yet.
-  // The try/catch is not necessary under normal circumstances, but helps a lot
-  // when debugging the installer, since this install task has to be executed
-  // unconditionally until the install_system_rebuild() install task is reached,
-  // as we cannot determine whether system tables have been installed already.
-  try {
-    drupal_install_schema('system');
-  }
-  catch (\Exception $e) {
-  }
+  require_once DRUPAL_ROOT . '/core/includes/schema.inc';
+  require_once DRUPAL_ROOT . '/core/modules/system/system.install';
+  drupal_install_schema('system');
 }
 
 /**
@@ -883,7 +878,6 @@ function install_system_rebuild(&$install_state) {
   // Otherwise, this phase is reached within the early-installer environment.
   // We need to unset all overrides and rebuild all necessary facilities to get
   // into a regular bootstrap state.
-  // Remove the service overrides.
   unset($conf['cache_classes']);
   unset($conf['keyvalue_default']);
   unset($conf['lock_backend']);
diff --git a/core/lib/Drupal/Core/Config/DatabaseStorage.php b/core/lib/Drupal/Core/Config/DatabaseStorage.php
index 1fb87b0..dac7402 100644
--- a/core/lib/Drupal/Core/Config/DatabaseStorage.php
+++ b/core/lib/Drupal/Core/Config/DatabaseStorage.php
@@ -145,7 +145,7 @@ public function encode($data) {
    */
   public function decode($raw) {
     $data = @unserialize($raw);
-    return is_array($data) ? $data : FALSE;
+    return is_array($data) ? $data : array();
   }
 
   /**
diff --git a/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php b/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php
index 064146c..f38c87a 100644
--- a/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php
+++ b/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php
@@ -39,14 +39,14 @@ function testCRUD() {
     $data = $this->storage->read($name);
     $this->assertIdentical($data, FALSE);
 
-    // Reading a name containing non-decodeable data returns FALSE.
+    // Reading a name containing non-decodeable data returns an array.
     $this->insert($name, '');
     $data = $this->storage->read($name);
-    $this->assertIdentical($data, FALSE);
+    $this->assertIdentical($data, array());
 
     $this->update($name, 'foo');
     $data = $this->storage->read($name);
-    $this->assertIdentical($data, FALSE);
+    $this->assertIdentical($data, array());
 
     $this->delete($name);