Teaching the menu frame that menu children aren't really part of its flow (like

the dropdown combo box does).

layout/xul/base/src/nsMenuFrame.cpp

@@ -26,7 +26,7 @@
 #include "nsIStyleContext.h"
 #include "nsCSSRendering.h"
 #include "nsINameSpaceManager.h"
-
+#include "nsLayoutAtoms.h"
 
 //
 // NS_NewMenuFrame
@@ -56,3 +56,15 @@ nsMenuFrame::nsMenuFrame()
 
 } // cntr
 
+NS_IMETHODIMP
+nsMenuFrame::FirstChild(nsIAtom*   aListName,
+                        nsIFrame** aFirstChild) const
+{
+  if (nsLayoutAtoms::popupList == aListName) {
+    *aFirstChild = mPopupFrames.FirstChild();
+  } else {
+    nsBoxFrame::FirstChild(aListName, aFirstChild);
+  }
+  return NS_OK;
+}
+

layout/xul/base/src/nsMenuFrame.h

@@ -23,13 +23,12 @@
 #ifndef nsMenuFrame_h__
 #define nsMenuFrame_h__
 
-
-#include "nsLeafFrame.h"
 #include "prtypes.h"
 #include "nsIAtom.h"
 #include "nsCOMPtr.h"
 
 #include "nsBoxFrame.h"
+#include "nsFrameList.h"
 
 nsresult NS_NewMenuFrame(nsIFrame** aResult) ;
 
@@ -39,8 +38,11 @@ class nsMenuFrame : public nsBoxFrame
 public:
   nsMenuFrame();
 
-protected:
+  NS_IMETHODIMP FirstChild(nsIAtom*   aListName,
+                           nsIFrame** aFirstChild) const;
 
+protected:
+  nsFrameList mPopupFrames;
 }; // class nsMenuFrame
 
 #endif

layout/xul/base/src/nsMenuPopupFrame.h

@@ -23,8 +23,6 @@
 #ifndef nsMenuPopupFrame_h__
 #define nsMenuPopupFrame_h__
 
-
-#include "nsLeafFrame.h"
 #include "prtypes.h"
 #include "nsIAtom.h"
 #include "nsCOMPtr.h"