diff --git a/drupal_web_test_case.php b/drupal_web_test_case.php
index f28c3b9..1a97e1b 100644
--- a/drupal_web_test_case.php
+++ b/drupal_web_test_case.php
@@ -224,9 +224,9 @@ abstract class DrupalTestCase {
     // The first element is the call. The second element is the caller.
     // We skip calls that occurred in one of the methods of our base classes
     // or in an assertion function.
-   while (($caller = $backtrace[1]) &&
-         ((isset($caller['class']) && isset($this->skipClasses[$caller['class']])) ||
-           substr($caller['function'], 0, 6) == 'assert')) {
+    while (($caller = $backtrace[1]) &&
+          ((isset($caller['class']) && isset($this->skipClasses[$caller['class']])) ||
+            substr($caller['function'], 0, 6) == 'assert')) {
       // We remove that call.
       array_shift($backtrace);
     }
@@ -1244,14 +1244,42 @@ class DrupalWebTestCase extends DrupalTestCase {
     ini_set('log_errors', 1);
     ini_set('error_log', $public_files_directory . '/error.log');
 
-    // Reset all statics and variables to perform tests in a clean environment.
-    $conf = array();
-
     // Set the test information for use in other parts of Drupal.
     $test_info = &$GLOBALS['drupal_test_info'];
     $test_info['test_run_id'] = $this->databasePrefix;
     $test_info['in_child_site'] = FALSE;
 
+    $this->setUpInstall(func_get_args(), $public_files_directory, $temp_files_directory);
+
+    // Log in with a clean $user.
+    $this->originalUser = $user;
+    session_save_session(FALSE);
+    $user = user_load(array('uid' => 1));
+
+    // Restore necessary variables.
+    variable_set('install_task', 'done');
+    variable_set('clean_url', $clean_url_original);
+    variable_set('site_mail', 'simpletest@example.com');
+
+    // Set up English language.
+    unset($GLOBALS['conf']['language_default']);
+    $language = language_default();
+
+    // Use the test mail class instead of the default mail handler class.
+    variable_set('smtp_library', drupal_get_path('module', 'simpletest') . '/simpletest.mail.inc');
+
+    set_time_limit($this->timeLimit);
+  }
+
+  /**
+   * Perform Drupal installation.
+   */
+  protected function setUpInstall(array $modules, $public_files_directory, $temp_files_directory) {
+    global $conf;
+
+    // Reset all statics and variables to perform tests in a clean environment.
+    $conf = array();
+
     include_once './includes/install.inc';
     drupal_install_system();
 
@@ -1270,7 +1298,6 @@ class DrupalWebTestCase extends DrupalTestCase {
     // either a single array argument or a variable number of string arguments.
     // @todo Remove this compatibility layer in Drupal 8, and only accept
     // $modules as a single array argument.
-    $modules = func_get_args();
     if (isset($modules[0]) && is_array($modules[0])) {
       $modules = $modules[0];
     }
@@ -1291,25 +1318,6 @@ class DrupalWebTestCase extends DrupalTestCase {
     // Run cron once in that environment, as install.php does at the end of
     // the installation process.
     drupal_cron_run();
-
-    // Log in with a clean $user.
-    $this->originalUser = $user;
-    session_save_session(FALSE);
-    $user = user_load(array('uid' => 1));
-
-    // Restore necessary variables.
-    variable_set('install_task', 'done');
-    variable_set('clean_url', $clean_url_original);
-    variable_set('site_mail', 'simpletest@example.com');
-
-    // Set up English language.
-    unset($GLOBALS['conf']['language_default']);
-    $language = language_default();
-
-    // Use the test mail class instead of the default mail handler class.
-    variable_set('smtp_library', drupal_get_path('module', 'simpletest') . '/simpletest.mail.inc');
-
-    set_time_limit($this->timeLimit);
   }
 
   /**
@@ -3132,3 +3140,104 @@ function simpletest_verbose($message, $original_file_directory = NULL, $test_cla
   }
   return FALSE;
 }
+
+/**
+ * Clone an existing database and use it for testing.
+ */
+class DrupalCloneTestCase extends DrupalWebTestCase {
+
+  /**
+   * Tables to exlude during data cloning, only their structure will be cloned.
+   *
+   * @var array
+   */
+  protected $excludeTables = array(
+    'cache',
+    'cache_block',
+    'cache_content',
+    'cache_filter',
+    'cache_form',
+    'cache_menu',
+    'cache_page',
+    'cache_update',
+    'watchdog',
+  );
+
+  /**
+   * Perform Drupal installation.
+   */
+  protected function setUpInstall() {
+    global $db_prefix;
+
+    // Store new database prefix.
+    $db_prefix_new = $db_prefix;
+    $db_prefix = $this->originalPrefix;
+
+    // Rebuild schema based on prefixed database and such.
+    $schemas = drupal_get_schema(NULL, TRUE);
+    // Create a list of prefixed source table names.
+    $sources = array();
+    foreach ($schemas as $name => $schema) {
+      $sources[$name] = $this->prefixTable($db_prefix, $name);
+    }
+
+    // Return to new prefix before performing cloning.
+    $db_prefix = $db_prefix_new;
+
+    // Clone each table into the new database.
+    foreach ($schemas as $name => $schema) {
+      $this->cloneTable($name, $sources[$name], $schema);
+    }
+  }
+
+  /**
+   * Clone an existing table structure and data.
+   *
+   * @param $name
+   *   Table name.
+   * @param $source
+   *   Source table name.
+   * @param $schema
+   *   A Schema API definition array.
+   */
+  protected function cloneTable($name, $source, $schema) {
+    $ret = array();
+    db_create_table($ret, $name, $schema);
+
+    $target = $this->prefixTable($this->databasePrefix, $name);
+    if (!in_array($name, $this->excludeTables)) {
+      if ($name == 'users') {
+        db_query('INSERT INTO ' . $target . ' SELECT * FROM ' . $source . ' WHERE uid <> 1');
+      }
+      else {
+        db_query('INSERT INTO ' . $target . ' SELECT * FROM ' . $source);
+      }
+    }
+  }
+
+  /**
+   * Correctly prefix a table name.
+   *
+   * This code is based off of core's db_prefix_tables().
+   *
+   * @param $db_prefix
+   *   Mixed array or string with prefixes.
+   * @param $name
+   *   String with the table name.
+   * @return
+   *   String with prefixed table name.
+   */
+  protected function prefixTable($db_prefix, $name) {
+    if (is_array($db_prefix)) {
+      if (array_key_exists($name, $db_prefix)) {
+        return $db_prefix[$name] . $name;
+      }
+      elseif (array_key_exists('default', $db_prefix)) {
+        return $db_prefix['default'] . $name;
+      }
+      return $name;
+    }
+    return $db_prefix . $name;
+  }
+
+}