gvfs: fix initial file size check

modules/access/gnomevfs.c

@@ -225,10 +225,11 @@ static int Open( vlc_object_t *p_this )
         return VLC_EGENERIC;
     }
 
-    if( p_sys->b_seekable && !p_sys->p_file_info->size )
+    if( p_sys->b_seekable
+    && !(p_sys->p_file_info->valid_fields & GNOME_VFS_FILE_INFO_FIELDS_SIZE) )
     {
         /* FIXME that's bad because all others access will be probed */
-        msg_Warn( p_access, "file %s is empty, aborting", psz_name );
+        msg_Warn( p_access, "file %s size is unknown, aborting", psz_name );
         gnome_vfs_file_info_unref( p_sys->p_file_info );
         gnome_vfs_uri_unref( p_uri);
         free( p_sys );