diff --git a/mozilla/browser/components/feeds/src/FeedWriter.js b/mozilla/browser/components/feeds/src/FeedWriter.js
index f8be34b0a59..b1f9e7b4e9c 100755
--- a/mozilla/browser/components/feeds/src/FeedWriter.js
+++ b/mozilla/browser/components/feeds/src/FeedWriter.js
@@ -566,13 +566,13 @@ FeedWriter.prototype = {
            * selected). If we don't show the filepicker here, it will be shown
            * when clicking "Subscribe Now".
            */
-          if (this._document.getElementById("handlersMenuList")
-                  .getAttribute("open") == "true") {
-            if (!this._chooseClientApp()) {
-              // Select the (per-prefs) selected handler if no application was
-              // selected
-              this._setSelectedHandler();
-            }
+          var popupbox = this._document.getElementById("handlersMenuList")
+                             .firstChild.boxObject;
+          popupbox.QueryInterface(Components.interfaces.nsIPopupBoxObject);
+          if (popupbox.popupState == "hiding" && !this._chooseClientApp()) {
+            // Select the (per-prefs) selected handler if no application was
+            // selected
+            this._setSelectedHandler();
           }
           break;
         default:
diff --git a/mozilla/layout/xul/base/public/nsIPopupBoxObject.idl b/mozilla/layout/xul/base/public/nsIPopupBoxObject.idl
index 8bf70f961d1..7effd112cfc 100644
--- a/mozilla/layout/xul/base/public/nsIPopupBoxObject.idl
+++ b/mozilla/layout/xul/base/public/nsIPopupBoxObject.idl
@@ -41,7 +41,7 @@
 
 interface nsIDOMElement;
 
-[scriptable, uuid(8714441F-0E24-4EB5-BE58-905F2854B4EB)]
+[scriptable, uuid(A41AF368-9F73-4D73-A058-49DD7E41F9EA)]
 interface nsIPopupBoxObject : nsISupports
 {
   /**
@@ -154,6 +154,15 @@ interface nsIPopupBoxObject : nsISupports
    * @param y vertical screen position
    */
   void openPopupAtScreen(in long x, in long y, in boolean isContextMenu);
+
+  /**
+   * Returns the state of the popup:
+   *   closed - the popup is closed
+   *   open - the popup is open
+   *   showing - the popup is in the process of being shown
+   *   hiding - the popup is in the process of being hidden
+   */
+  readonly attribute AString popupState;
 };
 
 %{C++
diff --git a/mozilla/layout/xul/base/src/nsPopupBoxObject.cpp b/mozilla/layout/xul/base/src/nsPopupBoxObject.cpp
index 7ffb809ac4f..d27d62e85b7 100644
--- a/mozilla/layout/xul/base/src/nsPopupBoxObject.cpp
+++ b/mozilla/layout/xul/base/src/nsPopupBoxObject.cpp
@@ -223,6 +223,32 @@ nsPopupBoxObject::EnableKeyboardNavigator(PRBool aEnableKeyboardNavigator)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsPopupBoxObject::GetPopupState(nsAString& aState)
+{
+  aState.AssignLiteral("closed");
+
+  nsMenuPopupFrame *menuPopupFrame = GetMenuPopupFrame();
+  if (menuPopupFrame) {
+    switch (menuPopupFrame->PopupState()) {
+      case ePopupShowing:
+      case ePopupOpen:
+        aState.AssignLiteral("showing");
+        break;
+      case ePopupOpenAndVisible:
+        aState.AssignLiteral("open");
+        break;
+      case ePopupHiding:
+      case ePopupInvisible:
+        aState.AssignLiteral("hiding");
+        break;
+    }
+  }
+
+  return NS_OK;
+}
+
+
 // Creation Routine ///////////////////////////////////////////////////////////////////////
 
 nsresult
diff --git a/mozilla/toolkit/content/tests/widgets/popup_shared.js b/mozilla/toolkit/content/tests/widgets/popup_shared.js
index 299367bd11e..77cc0a8c6f9 100644
--- a/mozilla/toolkit/content/tests/widgets/popup_shared.js
+++ b/mozilla/toolkit/content/tests/widgets/popup_shared.js
@@ -99,6 +99,18 @@ function eventOccured(event)
                   (eventitem[0] == event.type && eventitem[1] == event.target.id);
     ok(matches, test.testname + " " + event.type + " fired");
 
+    var expectedState;
+    switch (event.type) {
+      case "popupshowing": expectedState = "showing"; break;
+      case "popupshown": expectedState = "open"; break;
+      case "popuphiding": expectedState = "hiding"; break;
+      case "popuphidden": expectedState = "closed"; break;
+    }
+
+    if (expectedState)
+      is(event.originalTarget.state, expectedState,
+         test.testname + " " + event.type + " state");
+
     if (matches) {
       gTestEventIndex++
       if (events.length <= gTestEventIndex)
diff --git a/mozilla/toolkit/content/widgets/popup.xml b/mozilla/toolkit/content/widgets/popup.xml
index 0ad0d86d74a..4fe877f1562 100644
--- a/mozilla/toolkit/content/widgets/popup.xml
+++ b/mozilla/toolkit/content/widgets/popup.xml
@@ -31,6 +31,9 @@
         </getter>
       </property>
 
+      <property name="state" readonly="true"
+                onget="return this.popupBoxObject.popupState"/>
+
       <method name="openPopup">
         <parameter name="aAnchorElement"/>
         <parameter name="aPosition"/>