Reference Git branch start commit
Moreover I expect it work for history made from svn repo.
This post just gives first commit of repo creation and not feature branch start commit.
One Solution collect form web for “Reference Git branch start commit”
What you’re looking for is the command
git merge-base master feature-branch
will print the best common ancestor of those two branches, i.e. where they forked apart. (The documentation has pretty pretty pictures to clarify some of the interesting cases)