If you open a status panel, then mouse over the sidebar which can open a flyout, you end up with two panels open at the same time.
Created attachment 672513 [details] [diff] [review]
This is a simple fix.
A lower level fix in popup widget code isn't probably something we could uplift, because it could introduce regressions with popups that have nested menupopups.
Should this have a test?
Comment on attachment 672513 [details] [diff] [review]
a=me for 17/18
I couldn't reproduce this issue on FF 17 and FF 18b4 on Windows 7 x64 and Ubuntu x86.
Thanks Mario, can you try the latest 19.0a2 Aurora build?
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/20121214 Firefox/19.0 (20121214042017) WFM as FF17 and FF18b4 did.