Created attachment 8651316 [details] 2015.08.22 03-00-38.png STR: (Nightly (2015-08-20)) 1. Set Flash plugin state to "Ask to activate" 2. Enter fullscreen 3.A) Open http://www.twitch.tv/ and click player (it uses Flash) 3.B) Open https://element.yandex.ru/ and click "Установить" to initiate installation of the extension (or you can do the same with current page: I've attached the same extension Result: Popup's triangle is pointing Down Expectations: Popup's triangle should be pointing UP, where Location Bar is placed
I decided not to upload any extensions because that behavior can be seen in fullscreen on every AMO page E.g. https://addons.mozilla.org/en-US/firefox/addon/new-tab-in-tab-context-menu/
Bug 1210328 is the same and has a patch, so I'm duping this there.