If the igniter doesn't light, the gas valve will not open at all

That sure sounds like the safe way for it to work.

And it seems to agree with what I observed: the igniter was not
glowing, and I couldn't smell any gas at all.

I do wonder something though. IF the gas were to turn on (but not
ignite), would the smell be detectable? Or is the vent motor so
effective that all the unburnt gas would be vented and you wouldn't
smell it. Just wondering if anyone has any experience with such a
situation.

EJ