Description of problem:
API call packages.listFiles() would not return package objects which
have (by definition) no checksum (directories, symbolic links).

Version-Release number of selected component (if applicable):
spacewalk-java-1.2.39-29 / stock Satellite 5.4

How reproducible:
Always

Steps to Reproduce:
1. Satellite 5.4, some content imported
2. Find a package id of a package which is known to contain directory
   in its file list
3. Use following script to see whether or not are the package directories
   contained in the file list returned by packages.listFiles():
...
#!/usr/bin/perl

use strict;
use warnings;

use Frontier::Client;
use Data::Dumper;

my $HOST = 'satellite.domain.com';
my $user = 'user';
my $pass = 'password';
my $pid = 0;

my $client = new Frontier::Client(url => "https://$HOST/rpc/api");
my $session = $client->call('auth.login',$user, $pass);
my $pkglist = $client->call('packages.list_files', $session, $pid);
print Dumper($pkglist);
$client->call('auth.logout', $session);
...
  
Actual results:
packages.listFiles() does not return package objects without checksums.

Expected results:
packages.listFiles() will return package objects without checksums.

Additional info:
From com/redhat/rhn/common/db/datasource/xml/Package_queries.xml:

<mode name="package_files">
  <query params="pid">
SELECT C.name,
       F.file_size,
       CS.checksum,
       CS.checksum_type checksumtype,
       F.file_mode,
       F.linkto,
       TO_CHAR(F.mtime, 'YYYY-MM-DD HH24:MI:SS') AS MTIME
  FROM rhnPackageFile F, rhnPackageCapability C,
       rhnChecksumView CS
 WHERE F.package_id = :pid
   AND F.capability_id = C.id
   AND F.checksum_id = CS.id
ORDER BY UPPER(C.name)
  </query>
</mode>

Use of the inner join in the above statement is incorrect.