Index: modules/simpletest/drupal_web_test_case.php
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/drupal_web_test_case.php,v
retrieving revision 1.132
diff -u -r1.132 drupal_web_test_case.php
--- modules/simpletest/drupal_web_test_case.php	30 Jul 2009 10:46:53 -0000	1.132
+++ modules/simpletest/drupal_web_test_case.php	3 Aug 2009 21:06:42 -0000
@@ -376,6 +376,11 @@
    *   FALSE.
    */
   protected function error($message = '', $group = 'Other', array $caller = NULL) {
+    if ($group == 'User notice') {
+      // Instead of 'User notice' set by trigger_error(), use 'Debug'.
+      $group = 'Debug';
+    }
+
     return $this->assert('exception', $message, $group, $caller);
   }
 
Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.951
diff -u -r1.951 common.inc
--- includes/common.inc	31 Jul 2009 19:56:09 -0000	1.951
+++ includes/common.inc	3 Aug 2009 21:06:41 -0000
@@ -895,9 +895,11 @@
  *   An associative array with keys 'file', 'line' and 'function'.
  */
 function _drupal_get_last_caller($backtrace) {
-  // Errors that occur inside PHP internal functions
-  // do not generate information about file and line.
-  while ($backtrace && !isset($backtrace[0]['line'])) {
+  // Errors that occur inside PHP internal functions do not generate
+  // information about file and line. Ignore black listed functions.
+  $blacklist = array('dd');
+  while (($backtrace && !isset($backtrace[0]['line'])) ||
+         (isset($backtrace[1]['function']) && in_array($backtrace[1]['function'], $blacklist))) {
     array_shift($backtrace);
   }
 
@@ -4847,3 +4849,24 @@
   }
   variable_set('css_js_query_string', $new_character . substr($string_history, 0, 19));
 }
+
+/**
+ * Debug function used for outputting debug information.
+ *
+ * The debug information is passed on to trigger_error() after being converted
+ * to a string using _drupal_debug_message().
+ *
+ * @param $data
+ *   Data to be output.
+ * @param $label
+ *   Label to prefix the data.
+ * @param $print_r
+ *   Flag to switch between print_r() and var_export() for data conversion to
+ *   string. Set $print_r to TRUE when dealing with a recursive data structure
+ *   as var_export() will generate an error.
+ */
+function dd($data, $label = NULL, $print_r = FALSE) {
+  // Print $data contents to string.
+  $string = $print_r ? print_r($data, TRUE) : var_export($data, TRUE);
+  trigger_error(trim($label ? "$label: $string" : $string));
+}