Replace references to MergeRequestDiff#commits with st_commitsuse-st-commits-where-possible

when we care only about the number of commits

We do not have to instantiate all objects in this case.

1 files changed, 2 insertions, 2 deletions

diff --git a/app/services/merge_requests/refresh_service.rb b/app/services/merge_requests/refresh_service.rb
index 22596b4014a..e4056306bc4 100644
--- a/app/services/merge_requests/refresh_service.rb
+++ b/app/services/merge_requests/refresh_service.rb
@@ -63,7 +63,7 @@ module MergeRequests
         if merge_request.source_branch == @branch_name || force_push?
           merge_request.reload_diff
         else
-          mr_commit_ids = merge_request.commits.map(&:id)
+          mr_commit_ids = merge_request.commits_sha
           push_commit_ids = @commits.map(&:id)
           matches = mr_commit_ids & push_commit_ids
           merge_request.reload_diff if matches.any?
@@ -123,7 +123,7 @@ module MergeRequests
       return unless @commits.present?
 
       merge_requests_for_source_branch.each do |merge_request|
-        mr_commit_ids = Set.new(merge_request.commits.map(&:id))
+        mr_commit_ids = Set.new(merge_request.commits_sha)
 
         new_commits, existing_commits = @commits.partition do |commit|
           mr_commit_ids.include?(commit.id)