--- a/content/events/src/nsDOMKeyboardEvent.cpp
+++ b/content/events/src/nsDOMKeyboardEvent.cpp
@@ -18,16 +18,17 @@ nsDOMKeyboardEvent::nsDOMKeyboardEvent(m
   NS_ASSERTION(mEvent->eventStructType == NS_KEY_EVENT, "event type mismatch");
 
   if (aEvent) {
     mEventIsInternal = false;
   }
   else {
     mEventIsInternal = true;
     mEvent->time = PR_Now();
+    mEvent->AsKeyboardEvent()->mKeyNameIndex = KEY_NAME_INDEX_USE_STRING;
   }
 }
 
 NS_IMPL_ADDREF_INHERITED(nsDOMKeyboardEvent, nsDOMUIEvent)
 NS_IMPL_RELEASE_INHERITED(nsDOMKeyboardEvent, nsDOMUIEvent)
 
 NS_INTERFACE_MAP_BEGIN(nsDOMKeyboardEvent)
   NS_INTERFACE_MAP_ENTRY(nsIDOMKeyEvent)
@@ -97,19 +98,17 @@ nsDOMKeyboardEvent::GetModifierState(con
 
   *aState = GetModifierState(aKey);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDOMKeyboardEvent::GetKey(nsAString& aKeyName)
 {
-  if (!mEventIsInternal) {
-    mEvent->AsKeyboardEvent()->GetDOMKeyName(aKeyName);
-  }
+  mEvent->AsKeyboardEvent()->GetDOMKeyName(aKeyName);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDOMKeyboardEvent::GetCharCode(uint32_t* aCharCode)
 {
   NS_ENSURE_ARG_POINTER(aCharCode);
   *aCharCode = CharCode();

--- a/widget/EventForwards.h
+++ b/widget/EventForwards.h
@@ -31,19 +31,19 @@ namespace mozilla {
 typedef uint16_t Modifiers;
 
 #define NS_DEFINE_KEYNAME(aCPPName, aDOMKeyName) \
   KEY_NAME_INDEX_##aCPPName,
 
 enum KeyNameIndex
 {
 #include "nsDOMKeyNameList.h"
-  // There shouldn't be "," at the end of enum definition, this dummy item
-  // avoids bustage on some platforms.
-  NUMBER_OF_KEY_NAME_INDEX
+  // If a DOM keyboard event is synthesized by script, this is used.  Then,
+  // specified key name should be stored and use it as .key value.
+  KEY_NAME_INDEX_USE_STRING
 };
 
 #undef NS_DEFINE_KEYNAME
 
 } // namespace mozilla
 
 /**
  * All header files should include this header instead of *Events.h.

--- a/widget/TextEvents.h
+++ b/widget/TextEvents.h
@@ -119,16 +119,17 @@ public:
   static void GetDOMKeyName(mozilla::KeyNameIndex aKeyNameIndex,
                             nsAString& aKeyName)
   {
 #define NS_DEFINE_KEYNAME(aCPPName, aDOMKeyName) \
       case KEY_NAME_INDEX_##aCPPName: \
         aKeyName.Assign(NS_LITERAL_STRING(aDOMKeyName)); return;
     switch (aKeyNameIndex) {
 #include "nsDOMKeyNameList.h"
+      case KEY_NAME_INDEX_USE_STRING:
       default:
         aKeyName.Truncate();
         return;
     }
 #undef NS_DEFINE_KEYNAME
   }
 
   void AssignKeyEventData(const WidgetKeyboardEvent& aEvent, bool aCopyTargets)

--- a/widget/tests/test_assign_event_data.html
+++ b/widget/tests/test_assign_event_data.html
@@ -141,67 +141,67 @@ const kTests = [
         gUtils.sendNativeKeyEvent(WIN_KL_US, WIN_VK_A, 0, "a", "a");
       } else if (kIsMac) {
         gUtils.sendNativeKeyEvent(MAC_KL_US, MAC_VK_ANSI_A, 0, "a", "a");
       }
     },
     canRun: function () {
       return (kIsMac || kIsWin);
     },
-    todoMismatch: [ "key" ],
+    todoMismatch: [],
   },
   { description: "nsKeyEvent (keyup of 'a' key without modifiers)",
     targetID: "input-text", eventType: "keydown",
     dispatchEvent: function () {
       document.getElementById(this.targetID).value = "";
       document.getElementById(this.targetID).focus();
       if (kIsWin) {
         gUtils.sendNativeKeyEvent(WIN_KL_US, WIN_VK_A, 0, "a", "a");
       } else if (kIsMac) {
         gUtils.sendNativeKeyEvent(MAC_KL_US, MAC_VK_ANSI_A, 0, "a", "a");
       }
     },
     canRun: function () {
       return (kIsMac || kIsWin);
     },
-    todoMismatch: [ "key" ],
+    todoMismatch: [],
   },
   { description: "nsKeyEvent (keypress of 'b' key with Shift)",
     targetID: "input-text", eventType: "keypress",
     dispatchEvent: function () {
       document.getElementById(this.targetID).value = "";
       document.getElementById(this.targetID).focus();
       if (kIsWin) {
         gUtils.sendNativeKeyEvent(WIN_KL_US, WIN_VK_B, NATIVE_SHIFT_LEFT, "B", "B");
       } else if (kIsMac) {
         gUtils.sendNativeKeyEvent(MAC_KL_US, MAC_VK_ANSI_B, NATIVE_SHIFT_LEFT, "B", "B");
       }
     },
     canRun: function () {
       return (kIsMac || kIsWin);
     },
     // "defaultPrevented" becomes true because the editor consumes the keypress event.
-    todoMismatch: [ "key", "defaultPrevented" ],
+    todoMismatch: [ "defaultPrevented" ],
   },
   { description: "nsKeyEvent (keypress of 'c' key with Accel)",
     targetID: "input-text", eventType: "keypress",
     dispatchEvent: function () {
       document.getElementById(this.targetID).value = "";
       document.getElementById(this.targetID).focus();
       if (kIsWin) {
         gUtils.sendNativeKeyEvent(WIN_KL_US, WIN_VK_C, NATIVE_CONTROL_RIGHT, "\u0003", "c");
       } else if (kIsMac) {
         gUtils.sendNativeKeyEvent(MAC_KL_US, MAC_VK_ANSI_C, NATIVE_META_RIGHT, "c", "c");
       }
     },
     canRun: function () {
       return (kIsMac || kIsWin);
     },
     // "defaultPrevented" becomes true because the editor consumes the keypress event.
-    todoMismatch: [ "key", "defaultPrevented" ],
+    todoMismatch: [ "defaultPrevented" ],
   },
   { description: "nsMouseEvent (mousedown of left button without modifier)",
     targetID: "button", eventType: "mousedown",
     dispatchEvent: function () {
       synthesizeMouseAtCenter(document.getElementById(this.targetID),
                               { button: 0 });
     },
     canRun: function () {