Reproduction Steps:
1. Download project
2. Open Project
3. Run the YingDi_Test scene in editor.
4. Select "LocalClient-Player-....."
5. Open Animator window
6. Double press Attack button in Game view
Note: There is video how to do it
7. Notice that it momentarily enters Start state
Note There is video showing that.

Reproduced on version: Unity 5.4.1p4, 5.4.3f1, 5.5.0f1
Could not reproduce because of errors on neither 5.3 nor 5.6

Expected result: crossfade should transition to "attack_prepare1"
Result: Sometime it momentarily enters Start state and then "attack_prepare1"