Remove MergeRequest#to_raw and replace it with #to_diff and #to_patch

app/models/merge_request.rb

@@ -202,20 +202,22 @@ class MergeRequest < ActiveRecord::Base
     false
   end
 
-  def to_raw
-    FileUtils.mkdir_p(Rails.root.join("tmp", "patches"))
-    patch_path = Rails.root.join("tmp", "patches", "merge_request_#{self.id}.patch")
-
-    from = commits.last.id
-    to = source_branch
-
-    project.repo.git.run('', "format-patch" , " > #{patch_path.to_s}", {}, ["#{from}..#{to}", "--stdout"])
-
-    patch_path
-  end
-
   def mr_and_commit_notes
     commit_ids = commits.map(&:id)
     Note.where("(noteable_type = 'MergeRequest' AND noteable_id = :mr_id) OR (noteable_type = 'Commit' AND noteable_id IN (:commit_ids))", mr_id: id, commit_ids: commit_ids)
   end
+
+  # Returns the raw diff for this merge request
+  #
+  # see "git diff"
+  def to_diff
+    project.repo.git.native(:diff, {timeout: 30, raise: true}, "#{target_branch}...#{source_branch}")
+  end
+
+  # Returns the commit as a series of email patches.
+  #
+  # see "git format-patch"
+  def to_patch
+    project.repo.git.format_patch({timeout: 30, raise: true, stdout: true}, "#{target_branch}..#{source_branch}")
+  end
 end