Actually use the `skip_merges` option in Repository#commits

CHANGELOG

@@ -24,6 +24,7 @@ v 8.5.0 (unreleased)
   - Update the ExternalIssue regex pattern (Blake Hitchcock)
   - Optimized performance of finding issues to be closed by a merge request
   - Revert "Add IP check against DNSBLs at account sign-up"
+  - Actually use the `skip_merges` option in Repository#commits (Tony Chu)
   - Fix API to keep request parameters in Link header (Michael Potthoff)
   - Deprecate API "merge_request/:merge_request_id/comments". Use "merge_requests/:merge_request_id/notes" instead
   - Deprecate API "merge_request/:merge_request_id/...". Use "merge_requests/:merge_request_id/..." instead

app/models/repository.rb

@@ -78,7 +78,8 @@ class Repository
       offset: offset,
       # --follow doesn't play well with --skip. See:
       # https://gitlab.com/gitlab-org/gitlab-ce/issues/3574#note_3040520
-      follow: false
+      follow: false,
+      skip_merges: skip_merges
     }
 
     commits = Gitlab::Git::Commit.where(options)

spec/models/repository_spec.rb

@@ -239,4 +239,10 @@ describe Repository, models: true do
       it { is_expected.to eq(true) }
     end
   end
+
+  describe :skip_merged_commit do
+    subject { repository.commits(Gitlab::Git::BRANCH_REF_PREFIX + "'test'", nil, 100, 0, true).map{ |k| k.id } }
+
+    it { is_expected.not_to include('e56497bb5f03a90a51293fc6d516788730953899') }
+  end
 end