EllisLab/CodeIgniter — pull request #734 by narfbg (2011-12-02 12:56:28+00:00)
Title: Fix a file type detection bug in the Upload library

There were actually 2 bugs that could be triggered in different scenarios (both, introduced with the `_file_mime_type()` method by me, sorry):

- if the UNIX 'file' command was used, an empty argument was passed to it, due to an incorrect variable name (thanks to whoever fixed that in the 2.1-stable branch)
- if the `mime_content_type()` function was used, it turns out that it's possible for it to return FALSE or an empty string and thus resulting in the file being rejected