Zero length file entry create in file list when creating a torrent from directory/folder

[nicobubulle]

From beastly...@gmail.com on March 29, 2014 20:24:20

What steps will reproduce the problem? 1. Right click on a directory in file manager tab and select create new .torrent What is the expected output? What do you see instead? files in directory are listed as

// What environment are you using? 1. ruTorrent version is 3.6 svn 2404
2. rTorrent version is... 0.9.3/0.13.3
3. lighttpd 1.4.29 on debian
4. chromium Are some errors present in the web-server log? No Are some errors present in the browser error console? No Please provide any additional information below. The extra '/' ends up creating a zero length string in the torrent file. Some sites are not able to handle the zero length string and interpret it as a file.

The problem is in Torrent.php in the 'folder' function. The function sets $this->basedir and then strips any trailing '/' off. But it then calls the 'files' function with $dir which still has the trailing slash in place. Within the 'files' function, a '/' is added between the base path and each file name. This results in the double '/'.

The fix is pretty simple. Pass $this->basedir into the files function instead of $dir since $this->basedir has had any trailing slashes removed.

Here is the fix:
private function folder( $dir, $piece_length )
{
$this->basedir = $dir;
$len = strlen($this->basedir);
if(($len>1) && ($this->basedir[$len-1]=='/'))
$this->basedir = substr($this->basedir,0,-1);
return($this->files( self::scandir( $this->basedir ), $piece_length));
}

The problem above ends up creating a list with the first element being a zero length string. Since there should never be a valid reason to have a zero length string in the bencoded data, we can avoid it (and any other place where a zero length string might get created) by checking the length of the string at encoding time and return an empty string instead of a "0:" string.

Fix:
static private function encode_string( $string )
{
if( strlen( $string ))
return(strlen( $string ) . ':' . $string);
else
return "";
}

Original issue: http://code.google.com/p/rutorrent/issues/detail?id=900

[nicobubulle]

From doctor...@gmail.com on July 14, 2014 13:42:38

You can also change the torrent creation configuration to mktorrent.

[nicobubulle]

From beastly...@gmail.com on July 24, 2014 11:39:25

Yes. There are alternatives. I was just trying to provide a fix for code that doesn't work.

[nicobubulle]

From novik65 on July 25, 2014 03:54:08

Status: Fixed

[nicobubulle]

From novik65 on July 26, 2014 01:11:00

Since there should never be a valid reason to have a zero length string in the bencoded data

This is an incorrect assumption. Example:

Fragment from valid torrent:

comment45:Please seed this torrent as long as possible!13:comment.utf-80:10:created by

Fragment from invalid torrent (i.e. created with your patch):

comment45:Please seed this torrent as long as possible!13:comment.utf-810:created by

[nicobubulle]

From beastly...@gmail.com on July 26, 2014 11:11:00

Doh. Of course. Very bad assumption on my part. My apologies.