My example was actually flawed. You can generate that information by iterating through all the heads, and then working backwards to the first commit that is rea

My example was actually flawed. You can generate that information by iterating through all the heads, and then working backwards to the first commit that is reachable by another head. The better question, that Git actually can't answer, is whether E, F, and G were made under branch1 or branch2. Reflog could answer the question, but reflog is local only, and at least in theory temporary.