Anyone that uses Xnest will have gotten annoyed when it gets confused about the modifier state and it thinks e.g. Alt is pressed when its clearly not. Given that the bug has been around forever, it was seriously gratifying to fix it last week.
And before anyone says “Xnest sucks; use Xephr“, this is actually a bug in Xephr too … 🙂
Xnest sucks ! use Xephyr ( with http://projects.o-hand.com/xpatches/xephyr-fix-focus-in-modifier.patch )
Though I must admit I just stole your fix 😉