Associating non-existant floating ip used to return 500 error code. Now returns 400 instead of 404

Fix proposed to branch: master
Review: https://review.openstack.org/6367

Fix proposed to branch: master
Review: https://review.openstack.org/6824

Also when empty floating IP is passed as a request to associate, The error code returned is 500.
Expected:

Error message stating that the address does not exist or some such and the eroor code returned should be 404 as the floading IP is NotFound.

Actual:

ERROR: Associate floating ip failed (HTTP 500)

LOG:

REQ: curl -i http://10.233.52.27:8774/v2/732001bbd21942f1bec893c67c850066/servers/9cc6e27b-9cc8-4b9d-b116-5470773cc286/action -X POST -H "X-Auth-Project-Id: demo" -H "User-Agent: python-novaclient" -H "Content-Type: application/json" -H "Accept: application/json" -H "X-Auth-Token: 0c54452d1f38469a9e10dcbe060466df

REQ BODY: {"addFloatingIp": {"address": ""}}

RESP:{'date': 'Thu, 17 May 2012 11:30:29 GMT', 'status': '500', 'content-length': '74', 'content-type': 'application/json; charset=UTF-8', 'x-compute-request-id': 'req-d838b6dd-6035-44db-b185-c3f63f838070'} {"computeFault": {"message": "Associate floating ip failed", "code": 500}}

The same scenario is now returning ERROR CODE 400(Bad Request) instead of 404(Not Found).

The error code is expected to be 404 as in the case of boot a server with non-existant image ID. Refer to the following commands for further clarity:

stack@ubuntu:~/devstack$ nova floating-ip-list
+--------------+-------------+----------+------+
| Ip | Instance Id | Fixed Ip | Pool |
+--------------+-------------+----------+------+
| 172.24.4.225 | None | None | nova |
+--------------+-------------+----------+------+
stack@ubuntu:~/devstack$ nova add-floating-ip 898c3ce0-5e06-4bbc-bb51-e165279aaa86 172.24.4.22
ERROR: Error. Unable to associate floating ip (HTTP 400) (Request-ID: req-66cc5a04-614a-40f8-8b9c-9dc9588422c8)
stack@ubuntu:~/devstack$ nova add-floating-ip 898c3ce0-5e06-4bbc-bb51-e165279aaa86 ''
ERROR: Error. Unable to associate floating ip (HTTP 400) (Request-ID: req-0e9bf557-1a3c-4e8d-8627-faf4211cddb5)

But while booting a server with non-existant image ID:

stack@ubuntu:~/devstack$ nova image-list
+--------------------------------------+---------------------------------+--------+--------+
| ID | Name | Status | Server |
+--------------------------------------+---------------------------------+--------+--------+
| 128c9458-211f-4d48-87d8-4812ab57f197 | cirros-0.3.0-x86_64-uec-kernel | ACTIVE | |
| ccc520d2-bb46-4253-bedd-aa7f2b86ccae | cirros-0.3.0-x86_64-uec-ramdisk | ACTIVE | |
| d506424f-d702-4a9c-b2f4-47d82f490671 | cirros-0.3.0-x86_64-uec | ACTIVE | |
+--------------------------------------+---------------------------------+--------+--------+
stack@ubuntu:~/devstack$

send: u'GET /v2/b84f99644c8b4fd494e21a57f71cc5b7/images/d506424f-d702-4a9c-b2f4-47d82f490672 HTTP/1.1\r\nHost: 10.233.52.237:8774\r\nx-auth-project-id: demo\r\nx-auth-token: ee674ddf6dd1433f94cc848bfb1ec3b5\r\naccept-encoding: gzip, deflate\r\naccept: application/json\r\nuser-agent: python-novaclient\r\n\r\n'
reply: 'HTTP/1.1 404 Not Found\r\n'
header: Content-Length: 62
header: Content-Type: application/json; charset=UTF-8
header: X-Compute-Request-Id: req-a2a29620-15e3-45f3-a949-8b738fbb8acc
header: Date: Fri, 27 Jul 2012 17:34:09 GMT

Latest code

dims@dims-desktop:~/bin$ nova add-floating-ip f0b15425-394d-4ae1-a67d-4177f0752ce2 192.168.1.22
ERROR: floating ip not found (HTTP 404) (Request-ID: req-ec3e07f7-202b-4176-84cc-7ba69671cfcf)