I don't think I can explain the extent to which this simple papercut has been vicious and painful to me.
So many times, I've started writing some long post in a text field and accidentally lost it due to pressing some wrong keyboard shortcut (oops, you pressed backspace outside a text field! oops, we bound this key to 'reload the page', oops you closed the form by pressing ESC!). It's always a particular type of sinking feeling to have to start writing all over again.
Now there are extensions for this, and some of them even work. But what's my natural instinct when I have data in a text field I really don't want to lose because I would feel terrible losing it?
Well, ^A ^C and go paste it in a notepad, maybe even finish editing it there.
... and then Firefox quits, maybe because my layout switched between AZERTY and QWERTY by accident, maybe because my finger slipped between A and Q. And I get to stare at my desktop, crushed and defeated, having lost my data at the exact worst possible time...
I was seriously starting to consider maintaining my own Firefox fork, and I _cannot thank you enough_!