Connection to graphics console doesn't work if graphics configuration uses listen attribute in libvirt XML config

Created attachment 569683
Attempt to fix reported problem related to graphics console with listen address defined

Description of problem:
If I define a VM with graphics with listen address other than 127.0.0.1, virt-manager can't connect to this console.

Version-Release number of selected component (if applicable):

DistroRelease: Ubuntu 12.04
Package: virt-manager 0.9.1-1ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
Architecture: amd64
SourcePackage: virt-manager

How reproducible:
Always

Steps to Reproduce:

1. Define a VM with the following kind of graphics config in libvirt XML

   <graphics type='spice' port='5904' autoport='no' listen='10.10.0.16'>
      <listen type='address' address='10.10.0.16'/>
   </graphics>

2. Start the VM

3. Switch to the graphical console of the VM

Actual results:
virt-manager console stays black when trying to connect to the console. The Spice URI is incorrect, KVM is listening 10.10.0.16:5904 for Spice clients, not 127.0.0.1:5904.

Relevant output of virt-manager --debug when connecting without the attached patch applied:

2012-03-13 15:25:42,624 (console:1081): Starting connect process for proto=spice trans=None connhost=localhost connuser=None connport=None gaddr=127.0.0.1 gport=5904 gsocket=None
2012-03-13 15:25:42,624 (console:496): spice uri: spice://localhost?port=5904

Expected results:
virt-manager displays the console by connecting to 10.10.0.16:5904.

Relevant output of virt-manager --debug when connecting without the attached patch applied:
2012-03-13 15:26:36,552 (console:1081): Starting connect process for proto=spice trans=None connhost=10.10.0.16 connuser=None connport=5904 gaddr=10.10.0.16 gport=5904 gsocket=None
2012-03-13 15:26:36,552 (console:496): spice uri: spice://10.10.0.16?port=5904

Additional info:
Attached is a small patch that fixes this issue for me. But please review carefully, I really don't know if this is the proper way to fix this issue.

Thanks for the patch! Pushed now:

http://git.fedorahosted.org/git?p=virt-manager.git;a=commit;h=422c0216d806f7c71e7197279c032b7f58a42db3

But after inspecting the code I realize there are a few corner cases here where we aren't doing the right thing, so this code is about to be refactored :)