Created attachment 8641638 [details] Screenshot 2015-07-31 15.12.06.png User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0 Build ID: 20150630154324 Steps to reproduce: - Customize -> add bookmark bar to left of address bar. - Add some items without name (icon only). - Un-maximize firefox window. Actual results: It adds double arrow and displays icons in it, but there is space to display them without expanding. I can't explain, see screenshot. Expected results: It shouldn't display an expander, because there is room for icons.