Created attachment 757025 [details] actual.png User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36 Steps to reproduce: OSX 10.8.3 Firefox Trunk 24.0a1 (2013-06-01) 1.) Open a webpage. 2.) Shrink window to small 3.) Scroll down and to right at the sam time Actual results: Scrollbars overlap on each other. Expected results: They should NOT overlap. ***A screenshot is attached.***
Thanks for reporting. As you correctly mentioned in bug 873012, this behavior is intentional.