I've verified your patch fixes the crash for me. But I'm curious, have
I been running qemu in a nonstandard fashion, then? (Should I be
specifying more than just "-net user", normally?)
If so, I can make up a patch to amend the documentation.
I think Qemu should reject -net user only. Currently that seems to
mean that there is no nic, but still the vlan is connected to slirp
stack. That does not make any sense.
I usually run Qemu either without -net arguments or using the nice
qemu-launcher, which automatically adds -net nic,vlan=0 -net
user,vlan=0.
