After merge, the master branch shows a graph I did not understand at all.
So I was at commit id 4255f88, the other guy merged my code and proceeded to commit id 647b2fd, then I merged his 647b2fd and get c3193e1. But the branch tree did not show the graph I expected (as I pointed here), instead it shows my latest commit id c3193e1 is merged from that purple one, which I have no idea at all where does it come from?!
BTW, here I chose "create a commit even fast-forward", but I had tried fast-forward either and got the same result.
CloudPhone__Git_.png