Merge pull request #11910 from brendon/master

Use binary mode to write uploaded files [ci skip]

guides/source/form_helpers.md

@@ -605,7 +605,7 @@ The object in the `params` hash is an instance of a subclass of IO. Depending on
 ```ruby
 def upload
   uploaded_io = params[:person][:picture]
-  File.open(Rails.root.join('public', 'uploads', uploaded_io.original_filename), 'w') do |file|
+  File.open(Rails.root.join('public', 'uploads', uploaded_io.original_filename), 'wb') do |file|
     file.write(uploaded_io.read)
   end
 end