Replace references to MergeRequestDiff#commits with st_commits

when we care only about the number of commits

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

1 files changed, 11 insertions, 6 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 64990f8134e..bfb016df46d 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -22,7 +22,8 @@ class MergeRequest < ActiveRecord::Base
   after_create :ensure_merge_request_diff, unless: :importing?
   after_update :reload_diff_if_branch_changed
 
-  delegate :commits, :real_size, to: :merge_request_diff, prefix: nil
+  delegate :commits, :real_size, :commits_sha, :commits_count,
+    to: :merge_request_diff, prefix: nil
 
   # When this attribute is true some MR validation is ignored
   # It allows us to close or modify broken merge requests
@@ -662,7 +663,7 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def broken?
-    self.commits.blank? || branch_missing? || cannot_be_merged?
+    has_no_commits? || branch_missing? || cannot_be_merged?
   end
 
   def can_be_merged_by?(user)
@@ -770,10 +771,6 @@ class MergeRequest < ActiveRecord::Base
     diverged_commits_count > 0
   end
 
-  def commits_sha
-    commits.map(&:sha)
-  end
-
   def head_pipeline
     return unless diff_head_sha && source_project
 
@@ -871,4 +868,12 @@ class MergeRequest < ActiveRecord::Base
       @conflicts_can_be_resolved_in_ui = false
     end
   end
+
+  def has_commits?
+    commits_count > 0
+  end
+
+  def has_no_commits?
+    !has_commits?
+  end
 end