Bug 319532 [gnome]There is no feedback when use keyboard to navigate

disabled menuitem in Mozilla menu
r+sr=roc

layout/xul/base/src/nsMenuPopupFrame.cpp

@@ -1927,10 +1927,19 @@ PRBool
 nsMenuPopupFrame::IsValidItem(nsIContent* aContent)
 {
   nsIAtom *tag = aContent->Tag();
+  
+  PRBool skipNavigatingDisabledMenuItem;
+  GetPresContext()->LookAndFeel()->
+    GetMetric(nsILookAndFeel::eMetric_SkipNavigatingDisabledMenuItem,
+              skipNavigatingDisabledMenuItem);
 
-  return (tag == nsXULAtoms::menu ||
-          tag == nsXULAtoms::menuitem ||
-          tag == nsHTMLAtoms::option);
+  PRBool result = (tag == nsXULAtoms::menu ||
+                   tag == nsXULAtoms::menuitem ||
+                   tag == nsHTMLAtoms::option);
+  if (skipNavigatingDisabledMenuItem)
+    result = result && !IsDisabled(aContent);
+
+  return result;
 }
 
 PRBool 

widget/public/nsILookAndFeel.h

@@ -184,6 +184,7 @@ public:
     eMetric_SelectTextfieldsOnKeyFocus,                   // select textfields when focused via tab/accesskey?
     eMetric_SubmenuDelay,                                 // delay before submenus open
     eMetric_MenusCanOverlapOSBar,                         // can popups overlap menu/task bar?
+    eMetric_SkipNavigatingDisabledMenuItem,               // skip navigating to disabled menu item?
     eMetric_DragFullWindow,                               // show window contents while dragging?
     eMetric_DragThresholdX,                               // begin a drag if the mouse is moved further than the threshold while the button is down
     eMetric_DragThresholdY,

widget/src/gtk/nsLookAndFeel.cpp

@@ -387,6 +387,9 @@ NS_IMETHODIMP nsLookAndFeel::GetMetric(const nsMetricID aID, PRInt32 & aMetric)
     // we want XUL popups to be able to overlap the task bar.
     aMetric = 1;
     break;
+  case eMetric_SkipNavigatingDisabledMenuItem:
+    aMetric = 1;
+    break;
   case eMetric_DragFullWindow:
     aMetric = 1;
     break;

widget/src/gtk2/nsLookAndFeel.cpp

@@ -421,6 +421,9 @@ NS_IMETHODIMP nsLookAndFeel::GetMetric(const nsMetricID aID, PRInt32 & aMetric)
         // we want XUL popups to be able to overlap the task bar.
         aMetric = 1;
         break;
+    case eMetric_SkipNavigatingDisabledMenuItem:
+        aMetric = 1;
+        break;
     case eMetric_DragFullWindow:
         aMetric = 1;
         break;

widget/src/xpwidgets/nsXPLookAndFeel.cpp

@@ -93,6 +93,7 @@ nsLookAndFeelIntPref nsXPLookAndFeel::sIntPrefs[] =
   { "ui.isScreenReaderActive", eMetric_IsScreenReaderActive, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.menusCanOverlapOSBar", eMetric_MenusCanOverlapOSBar,
     PR_FALSE, nsLookAndFeelTypeInt, 0 },
+  { "ui.skipNavigatingDisabledMenuItem", eMetric_SkipNavigatingDisabledMenuItem, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.treeOpenDelay",
     eMetric_TreeOpenDelay, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.treeCloseDelay",