Honour workhorse provided file name

In the attempt to unify file uploading at workhorse level gitlab-org/gitlab-workhorse!230
we moved to a prefix-based tempfile creation in order to avoid upload collisions.

Artifacts and LFS uploads already set original_filename to workhorse provided filename

This commit add the same feature to `Gitlab::Middleware::Multipart`

lib/gitlab/middleware/multipart.rb

@@ -42,7 +42,7 @@ module Gitlab
             key, value = parsed_field.first
             if value.nil?
-              value = open_file(tmp_path)
+              value = open_file(tmp_path, @request.params["#{key}.name"])
               @open_files << value
             else
               value = decorate_params_value(value, @request.params[key], tmp_path)
@@ -70,7 +70,7 @@ module Gitlab
           case path_value
           when nil
-            value_hash[path_key] = open_file(tmp_path)
+            value_hash[path_key] = open_file(tmp_path, value_hash.dig(path_key, '.name'))
             @open_files << value_hash[path_key]
             value_hash
           when Hash
@@ -81,8 +81,8 @@ module Gitlab
           end
         end
-        def open_file(path)
-          ::UploadedFile.new(path, File.basename(path), 'application/octet-stream')
+        def open_file(path, name)
+          ::UploadedFile.new(path, name || File.basename(path), 'application/octet-stream')
         end
       end

spec/lib/gitlab/middleware/multipart_spec.rb

@@ -5,15 +5,17 @@ require 'tempfile'
 describe Gitlab::Middleware::Multipart do
   let(:app) { double(:app) }
   let(:middleware) { described_class.new(app) }
+  let(:original_filename) { 'filename' }
   it 'opens top-level files' do
     Tempfile.open('top-level') do |tempfile|
-      env = post_env({ 'file' => tempfile.path }, { 'file.name' => 'filename' }, Gitlab::Workhorse.secret, 'gitlab-workhorse')
+      env = post_env({ 'file' => tempfile.path }, { 'file.name' => original_filename }, Gitlab::Workhorse.secret, 'gitlab-workhorse')
       expect(app).to receive(:call) do |env|
         file = Rack::Request.new(env).params['file']
         expect(file).to be_a(::UploadedFile)
         expect(file.path).to eq(tempfile.path)
+        expect(file.original_filename).to eq(original_filename)
       end
       middleware.call(env)
@@ -34,13 +36,14 @@ describe Gitlab::Middleware::Multipart do
   it 'opens files one level deep' do
     Tempfile.open('one-level') do |tempfile|
-      in_params = { 'user' => { 'avatar' => { '.name' => 'filename' } } }
+      in_params = { 'user' => { 'avatar' => { '.name' => original_filename } } }
       env = post_env({ 'user[avatar]' => tempfile.path }, in_params, Gitlab::Workhorse.secret, 'gitlab-workhorse')
       expect(app).to receive(:call) do |env|
         file = Rack::Request.new(env).params['user']['avatar']
         expect(file).to be_a(::UploadedFile)
         expect(file.path).to eq(tempfile.path)
+        expect(file.original_filename).to eq(original_filename)
       end
       middleware.call(env)
@@ -49,13 +52,14 @@ describe Gitlab::Middleware::Multipart do
   it 'opens files two levels deep' do
     Tempfile.open('two-levels') do |tempfile|
-      in_params = { 'project' => { 'milestone' => { 'themesong' => { '.name' => 'filename' } } } }
+      in_params = { 'project' => { 'milestone' => { 'themesong' => { '.name' => original_filename } } } }
       env = post_env({ 'project[milestone][themesong]' => tempfile.path }, in_params, Gitlab::Workhorse.secret, 'gitlab-workhorse')
       expect(app).to receive(:call) do |env|
         file = Rack::Request.new(env).params['project']['milestone']['themesong']
         expect(file).to be_a(::UploadedFile)
         expect(file.path).to eq(tempfile.path)
+        expect(file.original_filename).to eq(original_filename)
       end
       middleware.call(env)