What happens to qubits if Swap Test fails?

[Dragonfall]

A swap-test is described here http://en.wikipedia.org/wiki/Quantum_digital_signature#Public_Key_should_be_the _same_for_every_recipient_.28Swap_Test.29

Now if the target qubits are identical, then after the swap test they are not disturbed. But what happens to them if they weren't identical? What do they become after the test?

[Dragonfall]

Suppose the target qubits were |A> and |B>, and they are not equal. After the swap test do they both become the mixed state:

0.5\left| A\right>\left< A\right| + 0.5\left| B\right>\left< B\right|

??