Invalidate the original overflow rect too when the frame moves. Bug 424766, r+sr=roc

layout/tables/nsTableFrame.cpp

@@ -6810,7 +6810,13 @@ nsTableFrame::InvalidateFrame(nsIFrame* aFrame,
   if (aIsFirstReflow ||
       aOrigRect.TopLeft() != aFrame->GetPosition() ||
       aOrigOverflowRect.TopLeft() != overflowRect.TopLeft()) {
-    aFrame->InvalidateOverflowRect();
+    // Invalidate the old and new overflow rects.  Note that if the
+    // frame moved, we can't just use aOrigOverflowRect, since it's in
+    // coordinates relative to the old position.  So invalidate via
+    // aFrame's parent, and reposition that overflow rect to the right
+    // place.
+    aFrame->Invalidate(overflowRect);
+    parent->Invalidate(aOrigOverflowRect + aOrigRect.TopLeft());
   } else {
     aFrame->InvalidateRectDifference(aOrigOverflowRect, overflowRect);
     parent->InvalidateRectDifference(aOrigRect, aFrame->GetRect());