removed the #ensure_ref_fetched from all controllers

also, I refactored the MergeRequest#fetch_ref method to express
the side-effect that this method has.

  MergeRequest#fetch_ref -> MergeRequest#fetch_ref!
  Repository#fetch_source_branch -> Repository#fetch_source_branch!

1 files changed, 3 insertions, 24 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 3133dc9e7eb..ccad8e102aa 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -426,7 +426,7 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def create_merge_request_diff
-    fetch_ref
+    fetch_ref!
 
     # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/37435
     Gitlab::GitalyClient.allow_n_plus_1_calls do
@@ -811,29 +811,14 @@ class MergeRequest < ActiveRecord::Base
     end
   end
 
-  def fetch_ref
-    write_ref
-    update_column(:ref_fetched, true)
+  def fetch_ref!
+    target_project.repository.fetch_source_branch!(source_project.repository, source_branch, ref_path)
   end
 
   def ref_path
     "refs/#{Repository::REF_MERGE_REQUEST}/#{iid}/head"
   end
 
-  def ref_fetched?
-    super ||
-      begin
-        computed_value = project.repository.ref_exists?(ref_path)
-        update_column(:ref_fetched, true) if computed_value
-
-        computed_value
-      end
-  end
-
-  def ensure_ref_fetched
-    fetch_ref unless ref_fetched?
-  end
-
   def in_locked_state
     begin
       lock_mr
@@ -975,10 +960,4 @@ class MergeRequest < ActiveRecord::Base
 
     project.merge_requests.merged.where(author_id: author_id).empty?
   end
-
-  private
-
-  def write_ref
-    target_project.repository.fetch_source_branch(source_project.repository, source_branch, ref_path)
-  end
 end