Frog spawn can be replaced and deleted by water buckets and lava buckets

The bug

Frog eggs can be replaced and deleted by water buckets.

Steps to reproduce

1. Dig a hole two blocks high.
2. Put water on the bottom.
3. Put the frog eggs on the second layer.
   
4. Use buckets on the second layer.
   
5. At this time frog eggs are replaced by water.