Don't use DiffCollection for deltas

app/models/commit.rb

@@ -373,7 +373,7 @@ class Commit
   def repo_changes
     changes = { added: [], modified: [], removed: [] }
-    raw_diffs(deltas_only: true).each do |diff|
+    raw_deltas.each do |diff|
       if diff.deleted_file
         changes[:removed] << diff.old_path
       elsif diff.renamed_file || diff.new_file
@@ -386,6 +386,10 @@ class Commit
     changes
   end
+  def raw_deltas
+    raw.deltas
+  end
+
   def merged_merge_request?(user)
     !!merged_merge_request(user)
   end

app/services/git_push_service.rb

@@ -67,7 +67,7 @@ class GitPushService < BaseService
       paths = Set.new
       @push_commits.each do |commit|
-        commit.raw_diffs(deltas_only: true).each do |diff|
+        commit.raw_deltas.each do |diff|
           paths << diff.new_path
         end
       end

app/workers/irker_worker.rb

@@ -142,10 +142,10 @@ class IrkerWorker
   end
   def files_count(commit)
-    diffs = commit.raw_diffs(deltas_only: true)
-    files = "#{diffs.real_size} file"
-    files += 's' if diffs.size > 1
+    diff_size = commit.raw_deltas.size
+    files = "#{diff_size} file"
+    files += 's' if diff_size > 1
     files
   end

lib/gitlab/git/commit.rb

@@ -192,6 +192,10 @@ module Gitlab
         Commit.diff_from_parent(raw_commit, options)
       end
+      def deltas
+        @deltas ||= diff_from_parent.each_delta.map { |d| Gitlab::Git::Diff.new(d) }
+      end
+
       def has_zero_stats?
         stats.total.zero?
       rescue

spec/services/git_push_service_spec.rb

@@ -584,7 +584,7 @@ describe GitPushService, services: true do
         commit = double(:commit)
         diff = double(:diff, new_path: 'README.md')
-        expect(commit).to receive(:raw_diffs).with(deltas_only: true).
+        expect(commit).to receive(:raw_deltas).
           and_return([diff])
         service.push_commits = [commit]