MoreLikeThis on a shard finds no interesting terms if the document queried is not in that shard

Running a MoreLikeThis query in a cloud works only when the document being queried exists in whatever shard serves the request. If the document is not present in the shard, no "interesting terms" are found and, consequently, no matches are found.

Steps to reproduce

• Edit example/solr/collection1/conf/solrconfig.xml and add this line, with the rest of the request handlers:

<requestHandler name="/mlt" class="solr.MoreLikeThisHandler" />

• Follow the simplest SolrCloud example to get two shards running.
• Hit this URL: http://localhost:8983/solr/collection1/mlt?mlt.fl=includes&q=id:3007WFP&mlt.match.include=false&mlt.interestingTerms=list&mlt.mindf=1&mlt.mintf=1
• Compare that output to that of this URL: http://localhost:7574/solr/collection1/mlt?mlt.fl=includes&q=id:3007WFP&mlt.match.include=false&mlt.interestingTerms=list&mlt.mindf=1&mlt.mintf=1

The former URL will return a result and list some interesting terms. The latter URL will return no results and list no interesting terms. It will also show this odd XML element:

<null name="response"/>