Created attachment 465241 [details]
Output produced by virsh with set debug flag

Description of problem:
I'm trying to attach an ISO-file to a virtual box virtual machine using virsh. 
The virtual machine is already created and registered at virtual box hypervisor.

Adding the ISO using VirtualBox Client Program works fine, but when I try to add it using virsh, at which it does not matter whether the virtual machine is powered on or off, I get:
error: Failed to attach device from disk_def.xml
error: Unknown failure


Version-Release number of selected component:
I'm using virsh
Compiled against library: libvir 0.8.6
Using library: libvir 0.8.6
Using API: VBOX 0.8.6
Running hypervisor: VBOX 3.2.12
git-commit: e37ff2004a891f31016ee747030b88050a83b479 

Steps to Reproduce:
1. create device definition in disk_def.xml containing:
	<disk type='file' device='cdrom'>
        	<source file='/path/to/ISO/file'/>
        	<target dev='hdc' bus='ide'/>
	</disk>
2. virsh -c vbox:///session attach-device virtual_machine disk_def.xml

Actual results:
Virsh shows following error messages:
error: Failed to attach device from disk_def.xml
error: Unknown failure

Expected results:
The ISO file should be attached at specified virtual machine.

Additional info:
I tried to debug virsh, when executing this task and it seems,that the virtual box api function call GetMachine in src/vbox/vbox_tmpl.c in line 4933 returns wrong values, causing the following test to fail. Which seems to cause the
"Unknown failure".