Fred the Fighter wants to survive another round in the ring with Bob the Barbarian. He's a skilled fighter, and has taken Combat Maneuver feats. Bob moves in to attack, but Fred readied to perform a Combat Maneuver. He specifically says "when the Barbarian attempts to melee attack me, I Bull Rush him". Bob is pushed outside of his reach from Fred.
What does Bob's turn look like? He's already moved, and was in the middle of attempting a melee attack (which no longer has a valid target).
Would any of these situations change the situation enough to justify another question?
- Bob's was already within reach, and it was his first attack in a Full Attack action
- Fred's Bull Rush leaves Bob near a different valid target (ally or not)
- Fred ready-Grapples Bob instead