palemoon-dev/platform/layout/generic/crashtests/508816-1.xul

<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
  style="direction: rtl">
 <scrollbox maxwidth="100" style="overflow: scroll;">
   <button label="One"/>
   <button label="Two"/>
   <button label="Three"/>
   <button label="Four and the rest of the numbers go here"/>
 </scrollbox>
</window>