When swimming in lava, the player can activate their elytra. This is not the case when swimming in water.

To reproduce

1. Create a large pool of lava
2. Equip elytra and fire work rockets
3. If in Survival, drink a potion of fire resistance
4. Jump into the pool
5. Press the Jump key (space by default) when submerged in the lava
6. Use your firework rockets

You can also try the same with a water pool, in which case the elytra won't activate and the firework rockets cannot be used.

Expected behaviour

This behaviour should be the same for water and lava. So either of the following would be expected to happen:

• The elytra would not activate while submerged in lava, just as is the case when swimming in water right now
• It should also be possible to enable elytra while submerged in water.

Observed behaviour

The elytra can be activated when submerged in lava, but not while in water.