diff --git a/dom/base/nsDOMClassInfo.cpp b/dom/base/nsDOMClassInfo.cpp
index f2be4e61bcd..5a6a9281d0c 100644
--- a/dom/base/nsDOMClassInfo.cpp
+++ b/dom/base/nsDOMClassInfo.cpp
@@ -9781,7 +9781,7 @@ nsHTMLPluginObjElementSH::Call(nsIXPConnectWrappedNative *wrapper,
 
   // If obj is a native wrapper, or if there's no plugin around for
   // this object, throw.
-  if (!ObjectIsNativeWrapper(cx, obj) || !pi) {
+  if (ObjectIsNativeWrapper(cx, obj) || !pi) {
     return NS_ERROR_NOT_AVAILABLE;
   }
 
diff --git a/layout/tools/reftest/runreftest.py b/layout/tools/reftest/runreftest.py
index a1ac1d3bb61..effad65119a 100644
--- a/layout/tools/reftest/runreftest.py
+++ b/layout/tools/reftest/runreftest.py
@@ -125,6 +125,7 @@ Are you executing $objdir/_tests/reftest/runreftest.py?""" \
     options.xrePath = getFullPath(options.xrePath)
 
   options.symbolsPath = getFullPath(options.symbolsPath)
+  options.utilityPath = getFullPath(options.utilityPath)
 
   profileDir = None
   try:
diff --git a/modules/plugin/test/mochitest/test_npruntime_npninvokedefault.html b/modules/plugin/test/mochitest/test_npruntime_npninvokedefault.html
index 094a0b5a3ba..798c8a77d93 100644
--- a/modules/plugin/test/mochitest/test_npruntime_npninvokedefault.html
+++ b/modules/plugin/test/mochitest/test_npruntime_npninvokedefault.html
@@ -51,8 +51,6 @@
     ["Boolean", "false", true],
     ["Boolean", new Boolean(false), true],
     ["Boolean", { "value": false }, true],
-    // Date object
-    // ["Date", "December 17, 1995 03:24:00", Date("December 17, 1995 03:24:00")],
     // Function object
     ["Function", "return 3", Function("return 3")],
     ["Function", "window.alert('test')", Function("window.alert('test')")],
@@ -87,6 +85,7 @@
   function runTests() {
     var plugin = document.getElementById("plugin1");
 
+    // Test calling NPN_InvokeDefault from within plugin code.
     for each (var test in tests) {
       var result = plugin.npnInvokeDefaultTest(test[0], test[1]);
       // serialize the two values for easy 
@@ -110,7 +109,17 @@
           BR()
           );
     }
-            
+    
+    // Test calling the invokedefault method of plugin-defined object
+    is(plugin(), "Test Plug-in", 
+        "calling NPN_InvokeDefault on plugin-defined Object doesn't work");
+    is(plugin(1), "Test Plug-in;1", 
+        "calling NPN_InvokeDefault on plugin-defined Object doesn't work");
+    is(plugin("test"), "Test Plug-in;test", 
+        "calling NPN_InvokeDefault on plugin-defined Object doesn't work");
+    is(plugin(undefined, -1, null), "Test Plug-in;undefined;-1;null", 
+        "calling NPN_InvokeDefault on plugin-defined Object doesn't work");
+  
     SimpleTest.finish();
   }
   </script>
diff --git a/modules/plugin/test/testplugin/README b/modules/plugin/test/testplugin/README
index 955b47b1b58..513842a8ef8 100644
--- a/modules/plugin/test/testplugin/README
+++ b/modules/plugin/test/testplugin/README
@@ -47,6 +47,10 @@ with the specified argument.  Returns the result of the invocation.
 If an error has occurred during the last stream or npruntime function,
 this will return a string error message, otherwise it returns "pass".
 
+* () - default method
+Returns a string consisting of the plugin name, concatenated with any 
+arguments passed to the method.
+
 == Private browsing ==
 
 The test plugin object supports the following scriptable methods:
diff --git a/modules/plugin/test/testplugin/nptest.cpp b/modules/plugin/test/testplugin/nptest.cpp
index 99c2cab4c79..9273db9a321 100644
--- a/modules/plugin/test/testplugin/nptest.cpp
+++ b/modules/plugin/test/testplugin/nptest.cpp
@@ -1192,7 +1192,30 @@ scriptableInvoke(NPObject* npobj, NPIdentifier name, const NPVariant* args, uint
 bool
 scriptableInvokeDefault(NPObject* npobj, const NPVariant* args, uint32_t argCount, NPVariant* result)
 {
-  return false;
+  ostringstream value;
+  value << PLUGIN_NAME;
+  for (uint32_t i = 0; i < argCount; i++) {
+    switch(args[i].type) {
+      case NPVariantType_Int32:
+        value << ";" << NPVARIANT_TO_INT32(args[i]);
+        break;
+      case NPVariantType_String: {
+        const NPString* argstr = &NPVARIANT_TO_STRING(args[i]);
+        value << ";" << argstr->UTF8Characters;
+        break;
+      }
+      case NPVariantType_Void:
+        value << ";undefined";
+        break;
+      case NPVariantType_Null:
+        value << ";null";
+        break;
+      default:
+        value << ";other";
+    }
+  }
+  STRINGZ_TO_NPVARIANT(strdup(value.str().c_str()), *result);
+  return true;
 }
 
 bool