Use null for default value of event handler attributes in XMLHttpRequest....

webkit/data/layout_tests/chrome/fast/js/resources/js-test-pre.js

 if (window.layoutTestController)
     layoutTestController.dumpAsText();
 
 function description(msg)
 {
     // For MSIE 6 compatibility
     var span = document.createElement("span");
     span.innerHTML = '<p>' + msg + '</p><p>On success, you will see a series of "<span class="pass">PASS</span>" messages, followed by "<span class="pass">TEST COMPLETE</span>".</p>';
     var description = document.getElementById("description");
     if (description.firstChild)
@@ skipping 65 matching lines @@
   else if (typeof(_av) == typeof(_bv))
     testFailed(_a + " should be " + _bv + ". Was " + _av + ".");
   else
     testFailed(_a + " should be " + _bv + " (of type " + typeof _bv + "). Was " + _av + " (of type " + typeof _av + ").");
 }
 
 function shouldBeTrue(_a) { shouldBe(_a, "true"); }
 function shouldBeFalse(_a) { shouldBe(_a, "false"); }
 function shouldBeNaN(_a) { shouldBe(_a, "NaN"); }
 
+function shouldBeNull(_a)
+{
+  var exception;
+  var _av;
+  try {
+     _av = eval(_a);
+  } catch (e) {
+     exception = e;
+  }
+
+  if (exception)
+    testFailed(_a + " should be null.  Threw exception " + exception);
+  else if (_av == null)
+    testPassed(_a + " is null.");
+  else
+    testFailed(_a + " should be null. was " + _av);
+}

[Pam (message me for reviews), 2009/04/16 21:59:31]

function shouldBeNull() already exists in the real version of this file (as
opposed to our forked copy).

+
 function shouldBeUndefined(_a)
 {
   var exception;
   var _av;
   try {
      _av = eval(_a);
   } catch (e) {
      exception = e;
   }
 
@@ skipping 43 matching lines @@
      exception = e;
   }
   
   var exceptionType = exception ? exception.toString().split(":")[0] : undefined;
 
   if (exception instanceof _e)
     testPassed(_a + " threw exception " + exceptionType + ".");
   else
     testFailed(_a + " should throw exception " + _e + ". Threw exception " + exceptionType + ".");
 }