Bug 1074469

Description of problem:
we have fixed it in bug 797227, but now qemu-ga-win hit it, qemu-guest-agent did not have such issue.

Version-Release number of selected component (if applicable):
host info:
2.6.32-447.el6.x86_64
qemu-kvm-rhev-0.12.1.2-2.422.el6.x86_64
guest info:
win7-64bit
qemu-ga-win-6.5-7
virtio-win-prewhql-0.1-74 

How reproducible:
100%

Steps to Reproduce:
1.Start guest with virtio serial and install qemu-ga-win-6.5-7 inside guest.
e.g:...-device virtio-serial-pci,id=virtio-serial0,max_ports=16,vectors=0,bus=pci.0,addr=0x3 -chardev socket,path=/tmp/qga.sock,server,nowait,id=qga0 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0
2.Connect the chardev socket in host side for sending commands to guest:
# nc -U /tmp/qga.sock readline
3.Send a unknown/unsupported/typo command in the host side, for example:

Actual results:
after step 3,
# nc -U /tmp/qga.sock readline
{"execute": "guest-ping"}
{"return": {}}
{ "execute": "system_reboot"}
{"error": {"desc": "The command system_reboot has not been found"}}

{"execute":"guest-suspend-"}
{"error": {"desc": "The command guest-suspend- has not been found"}}

{"execute":"guest-suspend-hybrid"}
{"error": {"desc": "this feature or command is not currently supported"}}

{"execute":"guest-s"}
{"error": {"desc": "The command guest-s has not been found"}}

Expected results:
{ "execute": "system_reboot"}
{"error": {"class": "CommandNotFound", "desc": "The command unknown-command has not been found", "data": {"name": "unknown-command"}}}

{"execute":"guest-suspend-"}
{"error": {"class": "CommandNotFound", "desc": "The command guest-suspend- has not been found", "data": {"name": "guest-suspend-"}}}

{"execute":"guest-suspend-hybrid"}
{"error": {"class": "Unsupported", "desc": "this feature or command is not currently supported", "data": {}}}

{"execute":"guest-s"}
{"error": {"class": "CommandNotFound", "desc": "The command guest-s has not been found", "data": {"name": "guest-s"}}}

Additional info: