NullPointerException with prefix query

gistfile1.txt

See https://groups.google.com/d/topic/elasticsearch/OA4rlKL5DNg/discussion for context.

The query :

{
    "query": {
        "prefix": {
            "field^2": "pre"
        }
    }
}

The stack trace:

[2012-11-12 15:22:22,931][DEBUG][action.search.type       ] [hyperion] [media01][0], node[UzKHSvvvQUavbkV2Y_PdZw], [P], s[STARTED]: Failed to execute [org.elasticsearch.action.search.SearchRequest@fb5c4d9]
org.elasticsearch.search.query.QueryPhaseExecutionException: [media01][0]: query[filtered(field^2:pre*)->cache(org.elasticsearch.index.search.nested.NonNestedDocsFilter@a2a5984b)],from[0],size[10]: Query Failed [Failed to execute main query]
        at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:182)
        at org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:234)
        at org.elasticsearch.search.action.SearchServiceTransportAction.sendExecuteQuery(SearchServiceTransportAction.java:140)
        at org.elasticsearch.action.search.type.TransportSearchQueryThenFetchAction$AsyncAction.sendExecuteFirstPhase(TransportSearchQueryThenFetchAction.java:80)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.performFirstPhase(TransportSearchTypeAction.java:205)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.performFirstPhase(TransportSearchTypeAction.java:192)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction$2.run(TransportSearchTypeAction.java:178)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:636)
Caused by: java.lang.NullPointerException
        at org.apache.lucene.search.MultiTermQuery.rewrite(MultiTermQuery.java:312)
        at org.apache.lucene.search.FilteredQuery.rewrite(FilteredQuery.java:219)
        at org.apache.lucene.search.IndexSearcher.rewrite(IndexSearcher.java:592)
        at org.elasticsearch.search.internal.ContextIndexSearcher.rewrite(ContextIndexSearcher.java:119)
        at org.apache.lucene.search.Searcher.createNormalizedWeight(Searcher.java:167)
        at org.apache.lucene.search.IndexSearcher.createNormalizedWeight(IndexSearcher.java:664)
        at org.elasticsearch.search.internal.ContextIndexSearcher.createNormalizedWeight(ContextIndexSearcher.java:133)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:342)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:330)
        at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:178)
        ... 9 more

Linked message in elasticsearch ML : https://groups.google.com/d/topic/elasticsearch/OA4rlKL5DNg/discussion