Issue #3120731 by alexpott, japerry, daffie, codersukanta, rfay, xjm, tim.plunkett, catch, andypost: Incorrect "Drupal already installed" if any database settings are wrong or unsatisfactory

core/includes/install.core.inc

@@ -20,6 +20,7 @@ use Drupal\Core\Form\FormState;
 use Drupal\Core\Installer\Exception\AlreadyInstalledException;
 use Drupal\Core\Installer\Exception\InstallerException;
 use Drupal\Core\Installer\Exception\NoProfilesException;
+use Drupal\Core\Installer\Form\SiteSettingsForm;
 use Drupal\Core\Installer\InstallerKernel;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageManager;
@@ -522,18 +523,14 @@ function install_begin_request($class_loader, &$install_state) {
   // accessing the database before it is set up yet.)
   drupal_maintenance_theme();
 
-  if ($install_state['database_verified']) {
+  if (!$install_state['database_verified']) {
+    // Do not install over an existing installation. The call to
+    // install_verify_database_ready() will throw an AlreadyInstalledException
+    // if this is the case.
+    install_verify_database_ready();
+  }
   // Verify the last completed task in the database, if there is one.
   $task = install_verify_completed_task();
-  }
-  else {
-    $task = NULL;
-
-    // Do not install over a configured settings.php.
-    if (Database::getConnectionInfo()) {
-      throw new AlreadyInstalledException($container->get('string_translation'));
-    }
-  }
 
   // Ensure that the active configuration is empty before installation starts.
   if ($install_state['config_verified'] && empty($task)) {
@@ -1176,16 +1173,28 @@ function install_verify_database_settings($site_path) {
 
 /**
  * Verify that the database is ready (no existing Drupal installation).
+ *
+ * @throws \Drupal\Core\Installer\Exception\AlreadyInstalledException
+ *   Thrown when the database already has a table that would be created by
+ *   installing the System module.
  */
 function install_verify_database_ready() {
   $system_schema = system_schema();
   end($system_schema);
   $table = key($system_schema);
 
+  $existing_install = FALSE;
   if ($database = Database::getConnectionInfo()) {
-    if (Database::getConnection()->schema()->tableExists($table)) {
-      throw new AlreadyInstalledException(\Drupal::service('string_translation'));
+    try {
+      $existing_install = Database::getConnection()->schema()->tableExists($table);
     }
+    // Do not trigger an error if the database query fails, since the database
+    // might not be set up yet.
+    catch (\Exception $e) {
+    }
+  }
+  if ($existing_install) {
+    throw new AlreadyInstalledException(\Drupal::service('string_translation'));
   }
 }
 
@@ -2223,6 +2232,25 @@ function install_check_requirements($install_state) {
         ];
       }
     }
+
+    // Check the database settings if they have been configured in settings.php
+    // before running the Drupal installer.
+    if ($database = Database::getConnectionInfo()) {
+      $request = Request::createFromGlobals();
+      $site_path = empty($install_state['site_path']) ? DrupalKernel::findSitePath($request, FALSE) : $install_state['site_path'];
+      $database = $database['default'];
+      $settings_file = './' . $site_path . '/settings.php';
+
+      $errors = install_database_errors($database, $settings_file);
+      if (count($errors)) {
+        $error_message = SiteSettingsForm::getDatabaseErrorsTemplate($errors);
+        $requirements['database_install_errors'] = [
+          'title' => t('Database settings'),
+          'description' => $error_message,
+          'severity' => REQUIREMENT_ERROR,
+        ];
+      }
+    }
   }
   return $requirements;
 }

core/lib/Drupal/Core/Installer/Form/SiteSettingsForm.php

@@ -194,7 +194,28 @@ class SiteSettingsForm extends FormBase {
     $errors = array_diff_key($errors, $form_errors);
 
     if (count($errors)) {
-      $error_message = [
+      $error_message = static::getDatabaseErrorsTemplate($errors);
+
+      // These are generic errors, so we do not have any specific key of the
+      // database connection array to attach them to; therefore, we just put
+      // them in the error array with standard numeric keys.
+      $form_errors[$database['driver'] . '][0'] = $this->renderer->renderPlain($error_message);
+    }
+
+    return $form_errors;
+  }
+
+  /**
+   * Gets the inline template render array to display the database errors.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslatableMarkup[] $errors
+   *   The database errors to list.
+   *
+   * @return mixed[]
+   *   The inline template render array to display the database errors.
+   */
+  public static function getDatabaseErrorsTemplate(array $errors) {
+    return [
       '#type' => 'inline_template',
       '#template' => '{% trans %}Resolve all issues below to continue the installation. For help configuring your database server, see the <a href="https://www.drupal.org/docs/8/install">installation handbook</a>, or contact your hosting provider.{% endtrans %}{{ errors }}',
       '#context' => [
@@ -204,14 +225,6 @@ class SiteSettingsForm extends FormBase {
         ],
       ],
     ];
-
-      // These are generic errors, so we do not have any specific key of the
-      // database connection array to attach them to; therefore, we just put
-      // them in the error array with standard numeric keys.
-      $form_errors[$database['driver'] . '][0'] = $this->renderer->renderPlain($error_message);
-    }
-
-    return $form_errors;
   }
 
   /**

core/tests/Drupal/FunctionalTests/Installer/InstallerExistingBrokenDatabaseSettingsTest.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Drupal\FunctionalTests\Installer;
+
+use Drupal\Core\Database\Database;
+
+/**
+ * Tests the installer with broken database connection info in settings.php.
+ *
+ * @group Installer
+ */
+class InstallerExistingBrokenDatabaseSettingsTest extends InstallerTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function prepareEnvironment() {
+    parent::prepareEnvironment();
+    // Pre-configure database credentials in settings.php.
+    $connection_info = Database::getConnectionInfo();
+
+    if ($connection_info['default']['driver'] !== 'mysql') {
+      $this->markTestSkipped('This test relies on overriding the mysql driver');
+    }
+
+    // Use a database driver that reports a fake database version that does
+    // not meet requirements.
+    unset($connection_info['default']['pdo']);
+    unset($connection_info['default']['init_commands']);
+    $connection_info['default']['driver'] = 'DrivertestMysqlDeprecatedVersion';
+    $namespace = 'Drupal\\driver_test\\Driver\\Database\\DrivertestMysqlDeprecatedVersion';
+    $connection_info['default']['namespace'] = $namespace;
+    $connection_info['default']['autoload'] = Database::findDriverAutoloadDirectory($namespace, \Drupal::root());
+
+    $this->settings['databases']['default'] = (object) [
+      'value' => $connection_info,
+      'required' => TRUE,
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUpSettings() {
+    // This form will never be reached.
+    return;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUpSite() {
+    // This form will never be reached.
+    return;
+  }
+
+  /**
+   * Tests the expected requirements problem.
+   */
+  public function testRequirementsProblem() {
+    $this->assertSession()->titleEquals('Requirements problem | Drupal');
+    $this->assertSession()->pageTextContains('Database settings');
+    $this->assertSession()->pageTextContains('Resolve all issues below to continue the installation. For help configuring your database server,');
+    $this->assertSession()->pageTextContains('The database server version 5.5.2 is less than the minimum required version');
+  }
+
+}