ref: 200e2fee22af9421f649525bf8f67cb945e94fc0
parent: ab639e6aa05f72268f63ad17ea68285ebba82f11
author: Ori Bernstein <ori@eigenstate.org>
date: Sat Aug 8 23:38:32 EDT 2020
Dedup parent commits in merging. When merging multiple branches (or redoing a merge for one branch) duplicate parents could sneak in. Don't do that.