git filter-branch duplicated commits

Question

I was rewriting my git repository's author history like explained here, however my original structure turned from

D (user 2) <-- master
|
C (user 2)                E (user 1) <-- branch 1
|                         |
+-------------------------+
|
B (user 1)
|
A (user 1)

into

D (user 1) <-- master     G (user 2, original/refs/heads/master)
|                         |
C (user 1)                F (user 2)                E (user 1) <-- branch 1
|                         |                         |
+-------------------------+-------------------------+
|
B (user 1)
|
A (user 1)

So the question is, how can I get rid of F and G altogether? original/refs/heads/master does not appear to be a branch, but I am also not entirely sure what it is.

Answer 1

Solved with:

git update-ref -d refs/original/refs/heads/master