[packagekit] Updated backends now crashing

[Anders F Björklund]

Richard Hughes wrote:

>> PackageKit-CRITICAL **: pk_backend_simulate_install_packages: assertion `backend->priv->desc->simulate_install_packages != NULL' failed
>> 
>>        g_return_if_fail (PK_IS_BACKEND (backend));
>>        g_return_if_fail (backend->priv->desc->install_packages != NULL);
> 
> Eek. That shouldn't happen.

The segfault is gone now (thanks for fixing), but it will still
abort with "SimulateInstallPackages not supported by backend"...

So the backend(s) aren't usable, until the simulate 4 methods
have been implemented. Possibly it can be done with a parameter:

if simulate:
    self._show_changeset(trans.getChangeSet())
else:
    self.ctrl.commitTransaction(trans, confirm=False)

--anders