i18n support missing. Language prefix is not added to the File Force link.

A solution is to change the function file_force_create_url
The are 2 changes:

function file_force_create_url($path, $add_query = TRUE) {
  global $language; // first change
  if (empty($path)) {
    return '';
  }
  $scheme = file_uri_scheme($path);
  if ($scheme == 'public') {
    $url = file_create_url((isset($language->prefix) & ($language->prefix <>'')) ? ($language->prefix . '/system/files_force/' . file_uri_target($path)) : ('system/files_force/' . file_uri_target($path))); // second change
  }
  else {
    $url = file_create_url($path);
  }
  if ($add_query) {
    // '&' for private uploads in non-clean URLs. Public downloads or clean URLs need '?' as there is no query.
    $separator = (variable_get('clean_url', FALSE) || ($scheme == 'public')) ? '?' : '&';
    $url .= $separator . 'download=1';
  }
  return $url;
}

The patch file is attached.

Hello,
Thanks for looking at this issue:

I uploaded different files for these languages.

So, the generated url for the Romanian language is the following:
http://local-website/system/files_force/pricelists/pricelist-2013-01-16-RO.pdf?download=1

and for English language:
http://local-website/system/files_force/pricelists/pricelist-2013-01-16-EN.pdf?download=1

Both urls doesn't have a prefix. The English link works (i didn't set a prefix for English in i18n settings).
But, the Romanian link doesn't work. The url that works is the following:
http://local-website/ro/system/files_force/pricelists/pricelist-2013-01-16-RO.pdf?download=1

Let me know if i missed something,

Best regards,
Andrew

Settings related to content type
I have created a content type called "Pricelist".
And configured the multilingual support according to the screenshot "1 multilingual support" and "2 multilingual support". See attached files please.
Then i added a "File" field type to Pricelist. See attched screenshot "3 upload pricelist field".
The field settings are shown in the image "4 field settings".
Settings related to /admin/config/regional/language
See screenshots:
"5 multilingual website settings"
"6 multilingual website settings - ENGLISH language"
"7 multilingual website settings - ROMANIAN language"
As you can see, i didn't set a path prefix for English language. But there is one for Romanian language.
Adding content
I have added a new content to Pricelist content type.
See atteched file "8 Adding English content".
"9 English content"
Then i press translate button and create a Romanian translation.
See attached "10 Translating content to Romanian".
So, at this step we have 2 nodes. One for English language and another for Romanian.
Check the file link which is create by drupal
For english node: "11 Checking the English file link created by drupal"
For romanian node: "12 Checking the Romanian file link created by drupal"
As you can see drupal doesn't place any prefix to the Romanian link.
Let's test now the file force link:
For english file link I write the following URL in the address bar: "mywebsite/system/files_force/pricelists/en_test.pdf?download=1"
And it works. The file is downloaded.
For romanian file link i write the following URL in the address bar: "mywebsite/system/files_force/pricelists/ro_test.pdf?download=1"
And it doens't work. I get the error: "13 error downloading RO file"
Now, let's add RO prefix to the link. So the final URL will be: "mywebsite/ro/system/files_force/pricelists/ro_test.pdf?download=1"
And it works, so the file is downloaded.

Hope this information helps. let me know if you need other information.

Added drupal and modules versions.
Added a little bit more details.