You cannot drown in water cauldrons

The Bug:

You cannot drown in water cauldrons.

Steps to Reproduce:

1. Place down a cauldron and fill it with a bucket of water.
2. Place a trapdoor above the cauldron.
3. Stand inside of the water cauldron and close the trapdoor.
4. Take note as to whether or not you can drown in water cauldrons.

Observed Behavior:

You cannot drown in water cauldrons.

Expected Behavior:

You would be able to drown in water cauldrons.