Issue #3247553 by alexpott, realityloop: $install_state['settings_verified']...

  $install_state['database_verified'] = install_verify_database_settings($site_path);

  // A valid settings.php has database settings and a hash_salt value. Other

  // settings will be checked by system_requirements().

  $install_state['settings_verified'] = $install_state['database_verified'] && (bool) Settings::get('hash_salt', FALSE);

  $install_state['settings_verified'] = $install_state['config_verified'] && $install_state['database_verified'] && (bool) Settings::get('hash_salt', FALSE);

  if ($install_state['settings_verified']) {

    try {

<?php

namespace Drupal\FunctionalTests\Installer;

use Drupal\Core\Database\Database;

/**

 * Verifies that installing from existing configuration works.

 *

 * @group Installer

 */

class InstallerExistingConfigExistingSettingsTest extends InstallerExistingConfigTest {

  /**

   * {@inheritdoc}

   *

   * Partially configures a preexisting settings.php file before invoking the

   * interactive installer.

   */

  protected function prepareEnvironment() {

    parent::prepareEnvironment();

    // Pre-configure hash salt.

    // Any string is valid, so simply use the class name of this test.

    $this->settings['settings']['hash_salt'] = (object) [

      'value' => __CLASS__,

      'required' => TRUE,

    ];

    // Pre-configure database credentials.

    $connection_info = Database::getConnectionInfo();

    unset($connection_info['default']['pdo']);

    unset($connection_info['default']['init_commands']);

    $this->settings['databases']['default'] = (object) [

      'value' => $connection_info,

      'required' => TRUE,

    ];

  }

}