Probably more of an oversight than a bug as it's nothing major, but figure it's something worth reporting. Essentially if you right-click or ignite TNT with a Fire Charge in creative it will consume the Fire Charge. I assume this is an oversight and am reporting since nothing else seems to actually consume the fire charge in creative.

"What I expected to happen... when using the fire charge in creative play to light TNT was to prime the TNT and retain the fire charge on my hot bar."

"What actually happened was... upon priming the TNT the Fire Charge was consumed from my toolbar and thus no longer in my inventory."

Steps to Reproduce are:
1. Place TNT block
2. Retrieve Fire charge from Creative menu, place in Hotbar
3. Prime TNT by interacting while holding Fire Charge.