diff --git a/modules/openid/openid.module b/modules/openid/openid.module
index 7673de8..eff1336 100644
--- a/modules/openid/openid.module
+++ b/modules/openid/openid.module
@@ -341,14 +341,17 @@ function openid_complete($response = array()) {
             $response['openid.claimed_id'] = $service['claimed_id'];
           }
           elseif ($service['version'] == 2) {
-            $response['openid.claimed_id'] = openid_normalize($response['openid.claimed_id']);
+            // Returned claimed id could have unique fragment hash to allow
+            // identifier recycling so we need to preserve it in response.
+            $response_claimed_id = openid_normalize($response['openid.claimed_id']);
+
             // OpenID Authentication, section 11.2:
             // If the returned Claimed Identifier is different from the one sent
             // to the OpenID Provider, we need to do discovery on the returned
             // identififer to make sure that the provider is authorized to
             // respond on behalf of this.
-            if ($response['openid.claimed_id'] != $claimed_id) {
-              $services = openid_discovery($response['openid.claimed_id']);
+            if ($response_claimed_id != $claimed_id) {
+              $services = openid_discovery($response_claimed_id);
               $uris = array();
               foreach ($services as $discovered_service) {
                 if (in_array('http://specs.openid.net/auth/2.0/server', $discovered_service['types']) || in_array('http://specs.openid.net/auth/2.0/signon', $discovered_service['types'])) {
@@ -589,8 +592,14 @@ function openid_association($op_endpoint) {
  */
 function openid_authentication($response) {
   $identity = $response['openid.claimed_id'];
-
   $account = user_external_load($identity);
+
+  // Tries to load user account if user_external_load fails due to possibly
+  // incompletely stored OpenID identifier in the authmap.
+  if (!isset($account->uid)) {
+    $account = _openid_invalid_openid_transition($identity, $response);
+  }
+
   if (isset($account->uid)) {
     if (!variable_get('user_email_verification', TRUE) || $account->login) {
       // Check if user is blocked.
@@ -634,7 +643,7 @@ function openid_authentication($response) {
       drupal_set_message(t('Account registration using the information provided by your OpenID provider failed due to the reasons listed below. Complete the registration by filling out the form below. If you already have an account, you can <a href="@login">log in</a> now and add your OpenID under "My account".', array('@login' => url('user/login'))), 'warning');
       // Append form validation errors below the above warning.
       foreach ($messages['error'] as $message) {
-        drupal_set_message( $message, 'error');
+        drupal_set_message($message, 'error');
       }
     }
 
@@ -650,6 +659,80 @@ function openid_authentication($response) {
   drupal_goto();
 }
 
+/**
+ * Provides transition for accounts with possibly invalid OpenID identifiers in authmap.
+ *
+ * This functions provides safe but not too much obtrusive procedure for users
+ * whose can't login with theirs OpenID identifiers. OpenID identifiers in the
+ * authmap could be incomplete due to invalid OpenID implementation in previous
+ * versions of Drupal (e.g. fragment part of the identifier could be missing).
+ * For more information read http://drupal.org/node/1120290.
+ *
+ * @param string $identity
+ *   The user's claimed OpenID identifier.
+ *
+ * @return
+ *   A fully-loaded user object if the user is found or FALSE if not found.
+ */
+function _openid_invalid_openid_transition($identity, $response) {
+  $account = FALSE;
+  $fallback_account = NULL;
+  $fallback_identity = $identity;
+
+  // Step 1: Try to strip the fragment if it is present.
+  if (strpos($fallback_identity, '#') !== FALSE) {
+    $fallback_identity = preg_replace('/#[^?]*/', '', $fallback_identity);
+    $fallback_account = user_external_load($fallback_identity);
+  }
+
+  // Step 2: Try to replace https with http. Openid providers often redirects
+  // from http to https, but Drupal didn't follow these redirects.
+  if (!$fallback_account && strpos($fallback_identity, 'https://') !== FALSE) {
+    $fallback_identity = str_replace('https://', 'http://', $fallback_identity);
+    $fallback_account = user_external_load($fallback_identity);
+  }
+
+  // Step 3: Try to use original identifier.
+  if (!$fallback_account && isset($_SESSION['openid']['user_login_values']['openid_identifier'])) {
+    $fallback_identity = openid_normalize($_SESSION['openid']['user_login_values']['openid_identifier']);
+    $fallback_account = user_external_load($fallback_identity);
+  }
+
+  if (isset($fallback_account->uid)) {
+    // Try to extract e-mail address from Simple Registration (SREG) or
+    // Attribute Exchanges (AX) keys.
+    $email = '';
+    $sreg_values = openid_extract_namespace($response, OPENID_NS_SREG, 'sreg');
+    $ax_values = openid_extract_namespace($response, OPENID_NS_AX, 'ax');
+    if (!empty($sreg_values['email']) && valid_email_address($sreg_values['email'])) {
+      $email = $sreg_values['email'];
+    }
+    elseif ($ax_mail_values = openid_extract_ax_values($ax_values, array('http://axschema.org/contact/email', 'http://schema.openid.net/contact/email'))) {
+      $email = current($ax_mail_values);
+    }
+
+    // If this e-mail address is the same as the e-mail address found in user
+    // account, login the user and update the claimed identifier.
+    if ($email && ($email == $fallback_account->mail || $email == $fallback_account->init)) {
+      $query = db_update('authmap')
+        ->fields(array('authname' => $identity))
+        ->condition('authname', $fallback_identity)
+        ->condition('uid', $fallback_account->uid)
+        ->condition('module', 'openid')
+        ->execute();
+      drupal_set_message(t('Successfully updated %invalid_identity with %identity.', array('%invalid_identity' => $fallback_identity, '%identity' => $identity)));
+      // Set the account to the found one.
+      $account =& $fallback_account;
+    }
+    else {
+      drupal_set_message(t('There is already an existing account which has assigned the OpenID identifier which you have provided. However, due to the bug in the previous version of the authentication system, we can\'t be sure that this account belongs to you. If you are new on this site, please continue with registering the new user account. If you already have had registered account on this site assigned to the provided OpenID identifier, please try to <a href="@url_password">reset the password</a> or contact the site administrator. In that case we are very sorry for this inconvenience.', array('@url_password' => 'user/password')), 'warning');
+    }
+  }
+
+  return $account;
+}
+
+
 function openid_association_request($public) {
   module_load_include('inc', 'openid');
 
diff --git a/modules/openid/openid.test b/modules/openid/openid.test
index 202a835..6a6d80a 100644
--- a/modules/openid/openid.test
+++ b/modules/openid/openid.test
@@ -89,12 +89,12 @@ class OpenIDFunctionalTestCase extends OpenIDWebTestCase {
     // Identifier is the URL of an XRDS document containing an OP Identifier
     // Element. The Relying Party sends the special value
     // "http://specs.openid.net/auth/2.0/identifier_select" as Claimed
-    // Identifier. The OpenID Provider responds with the actual identifier.
-    $identity = url('openid-test/yadis/xrds/dummy-user', array('absolute' => TRUE));
-    // Tell openid_test.module to respond with this identifier. The URL scheme
-    // is stripped in order to test that the returned identifier is normalized in
-    // openid_complete().
-    variable_set('openid_test_response', array('openid.claimed_id' => preg_replace('@^https?://@', '', $identity)));
+    // Identifier. The OpenID Provider responds with the actual identifier
+    // including fragment.
+    $identity = url('openid-test/yadis/xrds/dummy-user', array('absolute' => TRUE, 'fragment' => $this->randomName()));
+    // Tell openid_test.module to respond with this identifier. We test if
+    // openid_complete() process it right.
+    variable_set('openid_test_response', array('openid.claimed_id' => $identity));
     $this->addIdentity(url('openid-test/yadis/xrds/server', array('absolute' => TRUE)), 2, 'http://specs.openid.net/auth/2.0/identifier_select', $identity);
     variable_set('openid_test_response', array());
 
@@ -479,6 +479,114 @@ class OpenIDRegistrationTestCase extends OpenIDWebTestCase {
 }
 
 /**
+ * Test account registration using Simple Registration and Attribute Exchange.
+ */
+class OpenIDInvalidIdentifierTransitionTestCase extends OpenIDFunctionalTestCase  {
+  public static function getInfo() {
+    return array(
+      'name' => 'OpenID account update',
+      'description' => 'Tries to correct openid identifiers attached to accounts if theirs identifiers were stripped.',
+      'group' => 'OpenID'
+    );
+  }
+
+  function setUp() {
+    parent::setUp('openid', 'openid_test');
+    variable_set('user_register', USER_REGISTER_VISITORS);
+  }
+
+  /**
+   * Test OpenID transition with e-mail mismatch.
+   */
+  function testStrippedFragmentAccountEmailMismatch() {
+    $this->drupalLogin($this->web_user);
+
+    // Use a User-supplied Identity that is the URL of an XRDS document.
+    $identity = url('openid-test/yadis/xrds', array('absolute' => TRUE, 'fragment' => $this->randomName()));
+    $identity_stripped = preg_replace('/#[^?]*/', '', $identity);
+
+    $this->addIdentity($identity_stripped);
+
+    $this->drupalLogout();
+
+    // Test logging in via the login block on the front page.
+    $this->submitLoginForm($identity);
+    $this->assertLink(t('Log out'), 0, t('User was logged in.'));
+
+    $this->drupalLogout();
+
+    // Test logging in via the user/login page, provider will respond with full
+    // identifier (including fragment) but with different email, so we can't
+    // provide auto-update.
+    variable_set('openid_test_response', array(
+      'openid.claimed_id' => $identity,
+      'openid.sreg.nickname' => $this->web_user->name,
+      'openid.sreg.email' => 'invalid-' . $this->web_user->mail));
+    $edit = array('openid_identifier' => $identity_stripped);
+    $this->drupalPost('user/login', $edit, t('Log in'));
+
+    // Check we are on the OpenID redirect form.
+    $this->assertTitle(t('OpenID redirect'), t('OpenID redirect page was displayed.'));
+
+    // Submit form to the OpenID Provider Endpoint.
+    $this->drupalPost(NULL, array(), t('Send'));
+
+    // Verify user was redirected away from user/login to an accessible page.
+    $this->assertResponse(200);
+
+    // Verify the message.
+    $this->assertRaw(t('We found that there has been already an account which matches your OpenID identifier. If you are new on this site, please continue with registering the new user account. If you already had registered account on this site attached to the OpenID which you have provided, please try to <a href="@url_password">reset the password</a> or contact the site administrator. We are very sorry for this inadvertency.', array('@url_password' => 'user/password')), t('Message that OpenID identifier must be updated manually was displayed.'));
+
+    variable_set('openid_test_response', array());
+  }
+
+  /**
+   * Test OpenID auto transition with e-mail.
+   */
+  function testStrippedFragmentAccountAutoUpdateSreg() {
+    $this->drupalLogin($this->web_user);
+
+    // Use a User-supplied Identity that is the URL of an XRDS document.
+    $identity = url('openid-test/yadis/xrds', array('absolute' => TRUE, 'fragment' => $this->randomName()));
+    $identity_stripped = preg_replace('/#[^?]*/', '', $identity);
+
+    $this->addIdentity($identity_stripped);
+
+    $this->drupalLogout();
+
+    // Test logging in via the login block on the front page.
+    $this->submitLoginForm($identity);
+    $this->assertLink(t('Log out'), 0, t('User was logged in.'));
+
+    $this->drupalLogout();
+
+    // Test logging in via the user/login page, provider will respond with full
+    // identifier (including fragment) but with different email, so we can't
+    // provide auto-update.
+    variable_set('openid_test_response', array(
+      'openid.claimed_id' => $identity,
+      'openid.sreg.nickname' => $this->web_user->name,
+      'openid.sreg.email' => $this->web_user->mail));
+    $edit = array('openid_identifier' => $identity_stripped);
+    $this->drupalPost('user/login', $edit, t('Log in'));
+
+    // Check we are on the OpenID redirect form.
+    $this->assertTitle(t('OpenID redirect'), t('OpenID redirect page was displayed.'));
+
+    // Submit form to the OpenID Provider Endpoint.
+    $this->drupalPost(NULL, array(), t('Send'));
+
+    // Verify user was redirected away from user/login to an accessible page.
+    $this->assertResponse(200);
+
+    // Verify the message.
+    $this->assertRaw(t('Successfully updated %identity_stripped with %identity.', array('%identity_stripped' => $identity_stripped, '%identity' => $identity)), t('Message that OpenID identifier was updated automatically was displayed.'));
+
+    variable_set('openid_test_response', array());
+  }
+}
+
+/**
  * Test internal helper functions.
  */
 class OpenIDUnitTest extends DrupalWebTestCase {
diff --git a/modules/openid/tests/openid_test.module b/modules/openid/tests/openid_test.module
index bad1184..b5c023e 100644
--- a/modules/openid/tests/openid_test.module
+++ b/modules/openid/tests/openid_test.module
@@ -60,6 +60,12 @@ function openid_test_menu() {
     'access callback' => TRUE,
     'type' => MENU_CALLBACK,
   );
+  $items['openid-test/redirect'] = array(
+    'title' => 'OpenID Redirect',
+    'page callback' => 'openid_test_redirect',
+    'access callback' => TRUE,
+    'type' => MENU_CALLBACK,
+  );
   return $items;
 }
 
@@ -213,6 +219,16 @@ function openid_test_endpoint() {
 }
 
 /**
+ * Menu callback; regular HTML page with OpenID 2.0 <link> element.
+ */
+function openid_test_redirect() {
+  $url = variable_get('openid_test_redirect_url', '');
+  $http_response_code = variable_get('openid_test_redirect_http_reponse_code', 301);
+  header('Location: ' . $url, TRUE, $http_response_code);
+  exit();
+}
+
+/**
  * OpenID endpoint; handle "associate" requests (see OpenID Authentication 2.0,
  * section 8).
  *