Notice: Undefined index: alt in theme_file_icon()

Hi, I searched for this issue and nothing came up and it seems that it doesn't happen often, but the notice popped up for me and I figured that I would submit a patch. theme_file_entity_file_link() and theme_file_entity_download_link() both call theme('file_icon') without setting an alt tag variable, so I think that's where the problem lies. I just set it to take the filemime of the file.