Comment 17 for bug 50839

The difference (between pages on Linux that scroll fine and those that don't) may be in whether or not the Flash script handles the scroll event.

Currently the event is first passed (by GTK) to the Flash plugin (if the pointer is over the plugin window) and only comes to Mozilla if not handled by the plugin.

This means that scrolling behavior will be like FF2 where the element scrolled is the inner-most scrollable element containing the pointer position. (And perhaps the Flash script is handling the event even though there is nothing to scroll.)

To get the new behavior like other scrollable elements on trunk (where it is the pointer position when scrolling starts that is significant), perhaps something can be done with plugin_client_message_filter in nsWindow.cpp. The fun bit might be ensuring that the event still gets to the plugin when it should.