I’ve accidentally tapped the F and D keys together when using Alt+D to reach the address bar a few times. There is no matching shortcut or close-window command in the File menu, yet it instantly closes the window. Can someone tell me why?
Edit: Clarified first sentence and added screen shot for the doubters:
It closes whole windows. You can try it safely by opening a second Firefox whole window, open a few tabs on it, and then Alt-F, D and the entire window closes. (Your first Firefox window is unaffected.)
I’m still getting the hang of this site. I thought I replied to your comment but my reply showed separately. I get the same result as the OP.