file content sniffers vs filename extensions report

[Luca Ferretti <elle uca libero it>]

If I'm right now nautilus checks the extension on folder loading, then
sniffs the file content when selected.

Unfortunately there are some strange behaviors in sniffing.

1. Multi XML files
        I'm translating the GNOME system admin guide in Italian. This
        guide is physically broken in some files, one for chapter. On
        loading each sub-file is showed using the XML MIME icon, but
        when you select it, sniffer read it as HTML file. No troubles
        with main XML file and OMF file.
        
        Note that the file content sniffer for plain XML files searches
        for the "\<?xml" pattern in file, but it can be placed only in
        main file.
        
2. tar.bz2 files
        On folder loading those files are showed using
        gnome-mime-application-x-bizip-compressed-tar icon, on selection
        gnome-mime-application-x-bzip
        
        There are no troubles with tar.gz files.
        
3. XLS files
        This is really odd. I've a couple of spreadsheet to send to a
        Windows user, so I've to save them as xls. I choose in Gnumeric
        (HEAD !!) the "MS Excel (tm) 97/200/XP" option in file type. On
        folder loading Nautilus uses the proper XSL MIME icon, on file
        selection the sniffer says that the XLS file is a DOC (yeah, MS
        Word) file.