Fix back button scroll position - use of a double scrollbar

Create a course C1  with a lots of activities (you can use the MDK) Add several blocks in the C1 page (maybe html blocks with a large size) so to have a scroll bar in the block area Create a forum in with enough threads to have a page scroll in the forum view page On C1, scroll down to an activity and click on the activity A1 link Press the back Browser button Check that the page is scrolled down to the activity A1 (as it was before we clicked on the link). Go to the forum Scroll down to a forum thread FT1, down in the page Click on the forum thread FT1 Press the back Browser button Check that the page is scrolled down as it was before we clicked on the FT1, down in the page, to the FT1 thread