Sort the network graph both by commit date and topographically.30973-network-graph-sorted-by-date-and-topo

- Previously, we sorted commits by date, which seemed to work okay.

- The one edge case where this failed was when multiple commits have the same
  commit date (for example: when a range of commits are cherry picked with a
  single command, they all have the same commit date [and different author
  dates]).

- Commits with the same commit date would be sorted arbitrarily, and usually
  break the network graph.

- This commit solves the problem by both sorting by date, and by sorting
  topographically (parents aren't displayed until all their children are
  displayed)

- Include review comments from @adamniedzielski

A more detailed explanation is present here:
https://gitlab.com/gitlab-org/gitlab-ce/issues/30973#note_28706230

1 files changed, 1 insertions, 1 deletions

diff --git a/spec/lib/gitlab/git/repository_spec.rb b/spec/lib/gitlab/git/repository_spec.rb
index ddedb7c3443..fea186fd4f4 100644
--- a/spec/lib/gitlab/git/repository_spec.rb
+++ b/spec/lib/gitlab/git/repository_spec.rb
@@ -1062,7 +1062,7 @@ describe Gitlab::Git::Repository, seed_helper: true do
       end
 
       it "allows ordering by date" do
-        expect_any_instance_of(Rugged::Walker).to receive(:sorting).with(Rugged::SORT_DATE)
+        expect_any_instance_of(Rugged::Walker).to receive(:sorting).with(Rugged::SORT_DATE | Rugged::SORT_TOPO)
 
         repository.find_commits(order: :date)
       end