This has actually been fixed and known for some time. However, most of us are so well trained to not right click while holding food/lava/flint and steel, that it goes largely unnoticed.
This update happened somewhere near the beginning of November. I haven't been playing long and died to this bug once when I started playing, but noticed it was fixed a week or so later
When you right click, to open a chest or use a furnace, you no longer eat a piece of food.
I only tested this with food, but I'm assuming it works the same way preventing you from dumping water and lava on your chests.
Thanks Notch =D
It isn't a very common occurrence, but an annoying one when it happens.
So yeah its easy to go unnoticed.