Handle more than two paths in MergeRequest#diffs

app/controllers/concerns/diff_for_path.rb

@@ -2,7 +2,9 @@ module DiffForPath
   extend ActiveSupport::Concern
 
   def render_diff_for_path(diffs, diff_refs, project)
-    diff_file = safe_diff_files(diffs, diff_refs: diff_refs, repository: project.repository).first
+    diff_file = safe_diff_files(diffs, diff_refs: diff_refs, repository: project.repository).find do |diff|
+      diff.old_path == params[:old_path] && diff.new_path == params[:new_path]
+    end
 
     return render_404 unless diff_file
 

app/models/merge_request_diff.rb

@@ -145,10 +145,9 @@ def dump_diffs(diffs)
 
   def load_diffs(raw, options)
     if raw.respond_to?(:each)
-      if options[:paths]
-        old_path, new_path = options[:paths]
+      if paths = options[:paths]
         raw = raw.select do |diff|
-          old_path == diff[:old_path] && new_path == diff[:new_path]
+          paths.include?(diff[:old_path]) || paths.include?(diff[:new_path])
         end
       end