SOLR-1138: gracefully handle empty and null queries

git-svn-id: https://svn.apache.org/repos/asf/lucene/solr/trunk@771268 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -354,6 +354,7 @@ Bug Fixes
 
 41. SOLR-1135: Java replication creates Snapshot in the directory where Solr was launched (Jianhan Guo via shalin)
 
+42. SOLR-1138: Query Elevation Component now gracefully handles missing queries. (gsingers)
 
 Other Changes
 ----------------------

src/java/org/apache/solr/handler/component/QueryElevationComponent.java

@@ -52,6 +52,7 @@ import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortComparatorSource;
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.TermQuery;
+import org.apache.lucene.search.MatchAllDocsQuery;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.DOMUtil;
@@ -324,12 +325,12 @@ public class QueryElevationComponent extends SearchComponent implements SolrCore
     boolean force = params.getBool( FORCE_ELEVATION, forceElevation );
     
     Query query = rb.getQuery();
-    if( query == null ) {
+    String qstr = rb.getQueryString();
-      throw new SolrException( SolrException.ErrorCode.SERVER_ERROR,
+    if( query == null || qstr == null) {
-          "The QueryElevationComponent needs to be registered 'after' the query component" );
+      return;
     }
 
-    String qstr = getAnalyzedQuery( rb.getQueryString() );
+    qstr = getAnalyzedQuery(qstr);
     IndexReader reader = req.getSearcher().getReader();
     ElevationObj booster = null;
     try {

src/test/org/apache/solr/handler/component/QueryElevationComponentTest.java

@@ -86,6 +86,23 @@ public class QueryElevationComponentTest extends AbstractSolrTestCase {
     assertEquals( "xxxxyyyy", comp.getAnalyzedQuery( "XXXX YYYY" ) );
   }
 
+  public void testEmptyQuery() throws Exception {
+    SolrCore core = h.getCore();
+
+
+
+    //String query = "title:ipod";
+
+    Map<String,String> args = new HashMap<String, String>();
+    args.put( "q.alt", "*:*" );
+    args.put( "defType", "dismax");
+    //args.put( CommonParams.FL, "id,title,score" );
+    SolrQueryRequest req = new LocalSolrQueryRequest( core, new MapSolrParams( args) );
+    assertQ("Make sure QEC handles null queries", req, "//*[@numFound='0']");
+
+  }
+
+
   public void testSorting() throws IOException
   {
     SolrCore core = h.getCore();