SOLR-435 Improvements to SOLR-2001 (blank 'q') includes empty string check, dismax support, and test

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1306152 13f79535-47bb-0310-9956-ffa450edef68

solr/core/src/java/org/apache/solr/search/DisMaxQParser.java

@@ -22,7 +22,6 @@ import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.BooleanQuery;
 import org.apache.lucene.search.Query;
 import org.apache.solr.schema.IndexSchema;
-import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.DisMaxParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.NamedList;
@@ -92,7 +91,9 @@ public class DisMaxQParser extends QParser {
      */
     BooleanQuery query = new BooleanQuery(true);
 
-    addMainQuery(query, solrParams);
+    boolean notBlank = addMainQuery(query, solrParams);
+    if (!notBlank)
+      return null;
     addBoostQuery(query, solrParams);
     addBoostFunctions(query, solrParams);
 
@@ -151,7 +152,8 @@ public class DisMaxQParser extends QParser {
     }
   }
 
-  protected void addMainQuery(BooleanQuery query, SolrParams solrParams) throws ParseException {
+  /** Adds the main query to the query argument. If its blank then false is returned. */
+  protected boolean addMainQuery(BooleanQuery query, SolrParams solrParams) throws ParseException {
     Map<String, Float> phraseFields = SolrPluginUtils.parseFieldBoosts(solrParams.getParams(DisMaxParams.PF));
     float tiebreaker = solrParams.getFloat(DisMaxParams.TIE, 0.0f);
 
@@ -170,6 +172,8 @@ public class DisMaxQParser extends QParser {
     if (userQuery == null || userQuery.trim().length() < 1) {
       // If no query is specified, we may have an alternate
       altUserQuery = getAlternateUserQuery(solrParams);
+      if (altUserQuery == null)
+        return false;
       query.add(altUserQuery, BooleanClause.Occur.MUST);
     } else {
       // There is a valid query string
@@ -184,6 +188,7 @@ public class DisMaxQParser extends QParser {
         query.add(phrase, BooleanClause.Occur.SHOULD);
       }
     }
+    return true;
   }
 
   protected Query getAlternateUserQuery(SolrParams solrParams) throws ParseException {
@@ -192,7 +197,7 @@ public class DisMaxQParser extends QParser {
       QParser altQParser = subQuery(altQ, null);
       return altQParser.getQuery();
     } else {
-      throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "missing query string");
+      return null;
     }
   }
 

solr/core/src/java/org/apache/solr/search/ExtendedDismaxQParserPlugin.java

@@ -172,7 +172,7 @@ class ExtendedDismaxQParser extends QParser {
         query.add( altUserQuery , BooleanClause.Occur.MUST );
       } else {
         return null;
-        // throw new SolrException( SolrException.ErrorCode.BAD_REQUEST, "missing query string" );
+        // throw new ParseException("missing query string" );
       }
     }
     else {     

solr/core/src/java/org/apache/solr/search/LuceneQParserPlugin.java

@@ -19,7 +19,6 @@ package org.apache.solr.search;
 import org.apache.lucene.queryparser.classic.ParseException;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.Sort;
-import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.NamedList;
@@ -48,7 +47,6 @@ public class LuceneQParserPlugin extends QParserPlugin {
 }
 
 class LuceneQParser extends QParser {
-  String sortStr;
   SolrQueryParser lparser;
 
   public LuceneQParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
@@ -59,7 +57,7 @@ class LuceneQParser extends QParser {
   @Override
   public Query parse() throws ParseException {
     String qstr = getString();
-    if (qstr == null) return null;
+    if (qstr == null || qstr.length()==0) return null;
 
     String defaultField = getParam(CommonParams.DF);
     if (defaultField==null) {
@@ -95,6 +93,8 @@ class OldLuceneQParser extends LuceneQParser {
     // handle legacy "query;sort" syntax
     if (getLocalParams() == null) {
       String qstr = getString();
+      if (qstr == null || qstr.length() == 0)
+        return null;
       sortStr = getParams().get(CommonParams.SORT);
       if (sortStr == null) {
         // sort may be legacy form, included in the query string
@@ -107,7 +107,7 @@ class OldLuceneQParser extends LuceneQParser {
           qstr = commands.get(0);
         }
         else if (commands.size() > 2) {
-          throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "If you want to use multiple ';' in the query, use the 'sort' param.");
+          throw new ParseException("If you want to use multiple ';' in the query, use the 'sort' param.");
         }
       }
       setString(qstr);

solr/core/src/java/org/apache/solr/search/QParser.java

@@ -96,7 +96,8 @@ public abstract class QParser {
     lst.add(val);
   }
 
-  /** Create and return the <code>Query</code> object represented by <code>qstr</code>
+  /** Create and return the <code>Query</code> object represented by <code>qstr</code>.  Null MAY be returned to signify
+   * there was no input (e.g. no query string) to parse.
    * @see #getQuery()
    **/
   public abstract Query parse() throws ParseException;

solr/core/src/test/org/apache/solr/search/QueryParsingTest.java

@@ -16,6 +16,7 @@ package org.apache.solr.search;
  * limitations under the License.
  */
 
+import org.apache.lucene.search.Query;
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortField;
 import org.apache.solr.SolrTestCaseJ4;
@@ -35,6 +36,40 @@ public class QueryParsingTest extends SolrTestCaseJ4 {
     initCore("solrconfig.xml","schema.xml");
   }
 
+  /**
+   * Test that the main QParserPlugins people are likely to use
+   * as defaults fail with a consistent exception when the query string 
+   * is either empty or null.
+   * @see <a href="https://issues.apache.org/jira/browse/SOLR-435">SOLR-435</a>
+   * @see <a href="https://issues.apache.org/jira/browse/SOLR-2001">SOLR-2001</a>
+   */
+  public void testQParserEmptyInput() throws Exception {
+    
+    SolrQueryRequest req = req();
+    
+    final String[] parsersTested = new String[] {
+      OldLuceneQParserPlugin.NAME,
+      LuceneQParserPlugin.NAME,
+      DisMaxQParserPlugin.NAME,
+      ExtendedDismaxQParserPlugin.NAME
+    };
+
+    for (String defType : parsersTested) {
+      for (String qstr : new String[] {null, ""}) {
+        QParser parser = null;
+        try {
+          parser = QParser.getParser(qstr, defType, req);
+        } catch (Exception e) {
+          throw new RuntimeException("getParser excep using defType=" + 
+                                     defType + " with qstr="+qstr, e);
+        }
+        
+        Query q = parser.parse();
+        assertNull("expected no query",q);
+      }
+    }
+  }
+  
   @Test
   public void testSort() throws Exception {
     Sort sort;