Question

I’ve grabbed the latest code base of a gem called socialstream but I’m noticing an issue with file uploads on windows machines. The issue seems to be with the code below…

# Monkey patches to Ruby on Rails
#
# Use unix file util to prove the content type sent by the browser
class ActionDispatch::Http::UploadedFile
  def initialize_with_magic(*args, &block)
    initialize_without_magic(*args, &block)

    if (unix_file = `which file`.chomp).present? && File.exists?(unix_file)
      `#{ unix_file } -v 2>&1` =~ /^file-(.*)$/
      version = $1

      @content_type =
        if version >= "4.24"
          `#{ unix_file } -b --mime-type #{ @tempfile.path }`.chomp
        else
          `#{ unix_file } -bi #{ @tempfile.path }`.chomp =~ /(\w*\/[\w+-\.]*)/
          $1
        end
    end
  end

  alias_method_chain :initialize, :magic
end

the error is as follows

NoMethodError (undefined method chomp' for nil:NilClass):
social_stream-base (0.22.0) lib/rails/social_stream.rb:8:ininitialize_with_magic’
actionpack (3.2.5) lib/action_dispatch/http/upload.rb:39:in new'
actionpack (3.2.5) lib/action_dispatch/http/upload.rb:39:innormalize_parameters’
actionpack (3.2.5) lib/action_dispatch/http/parameters.rb:73:in block in normalize_parameters'
actionpack (3.2.5) lib/action_dispatch/http/parameters.rb:73:ineach’
actionpack (3.2.5) lib/action_dispatch/http/parameters.rb:73:in normalize_parameters'
actionpack (3.2.5) lib/action_dispatch/http/upload.rb:41:innormalize_parameters’
actionpack (3.2.5) lib/action_dispatch/http/parameters.rb:73:in block in normalize_parameters'
actionpack (3.2.5) lib/action_dispatch/http/parameters.rb:73:ineach’
actionpack (3.2.5) lib/action_dispatch/http/parameters.rb:73:in normalize_parameters'
actionpack (3.2.5) lib/action_dispatch/http/upload.rb:41:innormalize_parameters’

Is there a way to make this work on windows, either by using a gem, something i can install on windows, or rewriting the file?

Answer 1

Either delete or comment out the line:

alias_method_chain :initialize, :magic

This will stop it from hooking into ActionDispatch::HTTP::UploadFile#initialize

This also means you won’t get its benefit of “proving” the content-type, but I don’t know if that is really necessary for your application.