Swords no longer break blocks twice as fast

Swords used to (e.g. in 1.2.5) break blocks twice as fast as your hand. This only worked on blocks that could be harvested without a tool, and still caused 2 points of damage to the sword (as was normal for breaking a block with the wrong tool).

This no longer happens.

Since it wasn't mentioned in any changelog, I assume this is a bug, and not an intentional change.