Glass windows are nice on woodstoves. They allow one to enjoy a view of the fire, and to easily know when it's time to add more wood.
However, if you're adding a particularly large piece of wood to the fire, and having a problem getting it in place with the poker or by hand, the glass window should not be used to push the wood into place. Particularly if one accidentally uses more than minimal force when closing the door. The glass is tough, but not that tough.
Oops. I didn't pick a good night to put the woodstove temporarily out of commission, as it was -12 F outside. Luckily we had the backup propane heater, but it's nothing compared to wood heat.
$60 and an 80 mile round trip to the nearest specialty glass store later, The Hermit successfully replaced the window.
I am getting very sick of winter.