Eating a cake takes precedence over blocking with a sword, regardless of whether or not you are hungry

What I expected:
That my sword would block while I was looking at cake.

What happened:
My sword made infinite swinging motions at the cake, but did not damage the cake.

Steps to Reproduce:
1. Have sword selected in hand
2. Be close enough to cake while looking at it that the cake block is "highlighted"
3. Try blocking with sword

Additional Notes
Seems to occur in both survival and creative. Affects all swords.