we cannot serve ddocs list on node that doesn't host bucket yet [was: 500 Internal Server Error in request of pools/default/buckets/bucket-0/ddocs?_=1347042398100 during rebalance]

build-1693

./testrunner -i /tmp/rebalance_regression.ini get-logs=True -t swaprebalance.SwapRebalanceBasicTests.do_test,replica=1,num-buckets=3,num-swap=2,keys-count=1000000
http://qa.hq.northscale.net/job/centos-64-2.0-rebalance-regressions/30/console

test doesn't contain ddocs and response should be like as:

http://10.3.121.95:8091/pools/default/buckets/bucket-0/ddocs?_=1347042778195

noticed: it happens when on UI there are issues with cluster communications:

Lost connection to server at 10.3.121.95:8091. Repeating in 270 seconds.
Difficulties communicating with the cluster; displaying cached information

Request URL:http://10.3.121.95:8091/pools/default/buckets/bucket-0/ddocs?_=1347042398100
Request Method:GET
Status Code:500 Internal Server Error
Request Headersview source
Accept:application/json
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Authorization:Basic QWRtaW5pc3RyYXRvcjpwYXNzd29yZA==
Cache-Control:no-cache
Connection:keep-alive
Cookie:auth=QWRtaW5pc3RyYXRvcjpwYXNzd29yZA%3D%3D
Host:10.3.121.95:8091
invalid-auth-response:on
Pragma:no-cache
Referer:http://10.3.121.95:8091/index.html
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1
X-Requested-With:XMLHttpRequest
Query String Parametersview URL encoded
_:1347042398100
Response Headersview source
Cache-Control:no-cache
Content-Length:44
Content-Type:application/json
Date:Fri, 07 Sep 2012 18:26:38 GMT
Pragma:no-cache
Server:Couchbase Server 2.0.0-1693-rel-enterprise

Responce: ["Unexpected server error, request logged."]