Trying to access array offset on value of type bool in Drupal\openid_connect\Form\OpenIDConnectSettingsForm->buildForm()

Problem/Motivation

This error message appears when there is an exception when user information is retrieved with access token and $userinfo is set to FALSE.

Trying to access array offset on value of type bool in Drupal\openid_connect\Form\OpenIDConnectSettingsForm->buildForm() (line 273 of modules/contrib/openid_connect/src/Form/OpenIDConnectSettingsForm.php).

Steps to reproduce

Variable $userinfo is FALSE.
Variable $user_data is not empty.
Variable $results is FALSE.

private function buildContext(OpenIDConnectClientInterface $client, array $tokens) {
    $user_data = $client->decodeIdToken($tokens['id_token']);
    $userinfo = $client->retrieveUserInfo($tokens['access_token']);
    $provider = $client->getPluginId();

    $context = [
      'tokens' => $tokens,
      'plugin_id' => $provider,
      'user_data' => $user_data,
    ];
    $this->moduleHandler->alter('openid_connect_userinfo', $userinfo, $context);

    // Whether we have no usable user information.
    if (empty($user_data) && empty($userinfo)) {
      $this->logger->error('No user information provided by @provider (@code @error). Details: @details', ['@provider' => $provider]);
      return FALSE;
    }

    if ($userinfo && empty($userinfo['email'])) {
      $this->logger->error('No e-mail address provided by @provider (@code @error). Details: @details', ['@provider' => $provider]);
      return FALSE;
    }

    $sub = $this->extractSub($user_data, $userinfo);
    if (empty($sub)) {
      $this->logger->error('No "sub" found from @provider (@code @error). Details: @details', ['@provider' => $provider]);
      return FALSE;
    }

    /** @var \Drupal\user\UserInterface|bool $account */
    $account = $this->authmap->userLoadBySub($sub, $provider);
    $context = [
      'tokens' => $tokens,
      'plugin_id' => $provider,
      'user_data' => $user_data,
      'userinfo' => $userinfo,
      'sub' => $sub,
      'account' => $account,
    ];
    $results = $this->moduleHandler->invokeAll('openid_connect_pre_authorize', [
      $account,
      $context,
    ]);

    // Deny access if any module returns FALSE.
    if (in_array(FALSE, $results, TRUE)) {
      $this->logger->error('Login denied for @email via pre-authorize hook.', ['@email' => $userinfo['email']]);
      return FALSE;
    }

    // If any module returns an account, set local $account to that.
    foreach ($results as $result) {
      if ($result instanceof UserInterface) {
        $context['account'] = $result;
        break;
      }
    }

    return $context;
  }

Code will try to log an error with $userinfo['email'] but $userinfo is FALSE so we will get a warning.

Proposed resolution

Change this part of code:

if ($userinfo && empty($userinfo['email'])) {
      $this->logger->error('No e-mail address provided by @provider (@code @error). Details: @details', ['@provider' => $provider]);
      return FALSE;
    }

By this one:

if (!$userinfo || empty($userinfo['email'])) {
      $this->logger->error('No e-mail address provided by @provider (@code @error). Details: @details', ['@provider' => $provider]);
      return FALSE;
    }

This way, when $userinfo is FALSE, the error message "No e-mail address provided..." will be displayed instead of continuing code execution.

Remaining tasks

User interface changes

API changes

Data model changes