Created attachment 8775060 [details] Screenshot from 2016-07-27 10:23:12.png User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0 Build ID: 20160607223741 Steps to reproduce: When receiving new messages, some are individual and some are threaded and by default collapsed. When skipping through the message list, I often want to delete messages one by one. This works for individual messages as the button positions (...Archive, Junk, Delete, More) remain consistent. However when entering a collapsed threaded message, the two buttons (Archive, Delete) are assigned different screen positions.T Actual results: The result is that one usually accidentally clicks 'Archive' on a threaded message when one actually wants to click 'Delete' because 'Archive' has obtained the screen position that 'Delete' has for individual messages. Expected results: It would improve ergonomy and predictability of UI a lot if the buttons 'Archive' and 'Delete' for a selected threaded message were aligned with these two buttons in individual message view.
perhaps we should confirm bug 844475. There is also bug 1066738