Bug 397304, [@ nsListBoxBodyFrame::GetAvailableHeight], r+sr=bz, a=roc

layout/xul/base/src/nsListBoxBodyFrame.cpp

@@ -730,9 +730,12 @@ nsListBoxBodyFrame::GetAvailableHeight()
 {
   nsIScrollableFrame* scrollFrame
     = nsLayoutUtils::GetScrollableFrameFor(this);
+  if (scrollFrame) {
     nsIScrollableView* scrollView = scrollFrame->GetScrollableView();
     return scrollView->View()->GetBounds().height;
   }
+  return 0;
+}
 
 nscoord
 nsListBoxBodyFrame::GetYPosition()
@@ -1011,6 +1014,9 @@ nsListBoxBodyFrame::VerticalScroll(PRInt32 aPosition)
 {
   nsIScrollableFrame* scrollFrame
     = nsLayoutUtils::GetScrollableFrameFor(this);
+  if (!scrollFrame) {
+    return;
+  }
 
   nsPoint scrollPosition = scrollFrame->GetScrollPosition();