I found that when I used 'fileHistoryWalk' for a file.
The result showed the last commit is red one rather then blue one.
also the merge commit between red and blue didn't show, either.
How can I really know the all commit about a file including merge commit?
I am sure the merge commit (blue one) is modified my file which I wanted to focus.
I also know that when you see the file history in gitKraken. It doesn't show either.
Thanks