Search for branches with special characters causes NPE

2015-01-22 09:44:33,033 DEBUG [qtp715504968-526 ] fisheye noClassMethodInfo - end request in 195ms GET /changelog-ajax/FE-git?q=%60&limit=51&command=branches&_=1421919872793 sessionid=5cihscy7wa001crtp1ze8oej4
2015-01-22 09:44:33,034 WARN  [qtp715504968-526 ] org.eclipse.jetty.servlet.ServletHandler noClassMethodInfo - /changelog-ajax/FE-git
java.lang.NullPointerException
        at com.atlassian.fecru.search.common.lucene.PhraseScorer.<init>(PhraseScorer.java:71)
        at com.atlassian.fecru.search.common.lucene.ExactPhraseScorer.<init>(ExactPhraseScorer.java:38)
        at com.atlassian.fecru.search.common.lucene.PrefixPhraseQuery$PrefixPhraseQueryWeigh.scorer(PrefixPhraseQuery.java:185)
        at org.apache.lucene.search.BooleanQuery$BooleanWeight.scorer(BooleanQuery.java:306)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:210)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:199)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:177)
        at org.apache.lucene.search.Searcher.search(Searcher.java:49)
        at com.cenqua.fisheye.rep.DefaultCrossRepositorySearcher$1.perform(DefaultCrossRepositorySearcher.java:191)
        at com.cenqua.fisheye.rep.DefaultCrossRepositorySearcher$1.perform(DefaultCrossRepositorySearcher.java:185)
        at com.cenqua.fisheye.lucene.LuceneConnection.withIndexSearcher(LuceneConnection.java:306)
        at com.cenqua.fisheye.rep.DefaultCrossRepositorySearcher.findRecentlyModifiedBranches(DefaultCrossRepositorySearcher.java:185)
        at com.cenqua.fisheye.web.ChangelogAjaxServlet.getBranches(ChangelogAjaxServlet.java:241)
        at com.cenqua.fisheye.web.ChangelogAjaxServlet.handleRequest(ChangelogAjaxServlet.java:156)