diff --git a/modules/simpletest/tests/session.test b/modules/simpletest/tests/session.test
index 097503b..32d00b8 100644
--- a/modules/simpletest/tests/session.test
+++ b/modules/simpletest/tests/session.test
@@ -478,6 +478,56 @@ class SessionHttpsTestCase extends DrupalWebTestCase {
   }
 
   /**
+   * Tests that empty session IDs do not cause unrelated sessions to load.
+   */
+  public function testEmptySessionId() {
+    global $is_https;
+
+    if ($is_https) {
+      $secure_session_name = session_name();
+    }
+    else {
+      $secure_session_name = 'S' . session_name();
+    }
+
+    // Enable mixed mode for HTTP and HTTPS.
+    variable_set('https', TRUE);
+
+    $admin_user = $this->drupalCreateUser(array('access administration pages'));
+    $standard_user = $this->drupalCreateUser(array('access content'));
+
+    // Login the admin user first.
+    // We cannot use $this->drupalLogin() here because we need to use the
+    // special http.php URLs.
+    $edit = array(
+      'name' => $admin_user->name,
+      'pass' => $admin_user->pass_raw
+    );
+    $this->drupalGet('user');
+    $form = $this->xpath('//form[@id="user-login"]');
+    $form[0]['action'] = $this->httpUrl('user');
+    $this->drupalPost(NULL, $edit, t('Log in'));
+
+    $this->curlClose();
+
+    // Now start a session for the standard user.
+    $edit = array(
+      'name' => $standard_user->name,
+      'pass' => $standard_user->pass_raw
+    );
+    $this->drupalGet('user');
+    $form = $this->xpath('//form[@id="user-login"]');
+    $form[0]['action'] = $this->httpsUrl('user');
+    $this->drupalPost(NULL, $edit, t('Log in'));
+
+    // Make the secure session cookie blank.
+    curl_setopt($this->curlHandle, CURLOPT_COOKIE, "$secure_session_name=");
+    $this->drupalGet($this->httpsUrl('user'));
+    $this->assertNoText($admin_user->name, 'User is not logged in as admin');
+    $this->assertNoText($standard_user->name, "The user's own name is not displayed because the invalid session ccokie has logged them out.");
+  }
+
+  /**
    * Test that there exists a session with two specific session IDs.
    *
    * @param $sid