From 139f71599e0e4e081b4b6fd1aa416e73ac31cbf7 Mon Sep 17 00:00:00 2001
From: Mark Robert Miller <markrmiller@apache.org>
Date: Wed, 3 Dec 2008 14:15:22 +0000
Subject: [PATCH] LUCENE-1246: check for null sub queries so that
 BooleanQuery.toString does not throw NullPointerException.

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@722897 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/lucene/search/BooleanQuery.java  | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/java/org/apache/lucene/search/BooleanQuery.java b/src/java/org/apache/lucene/search/BooleanQuery.java
index 4f2a5693907..0bf71ca7bb4 100644
--- a/src/java/org/apache/lucene/search/BooleanQuery.java
+++ b/src/java/org/apache/lucene/search/BooleanQuery.java
@@ -424,12 +424,17 @@ public class BooleanQuery extends Query {
         buffer.append("+");
 
       Query subQuery = c.getQuery();
-      if (subQuery instanceof BooleanQuery) {	  // wrap sub-bools in parens
-        buffer.append("(");
-        buffer.append(c.getQuery().toString(field));
-        buffer.append(")");
-      } else
-        buffer.append(c.getQuery().toString(field));
+      if (subQuery != null) {
+        if (subQuery instanceof BooleanQuery) {	  // wrap sub-bools in parens
+          buffer.append("(");
+          buffer.append(subQuery.toString(field));
+          buffer.append(")");
+        } else {
+          buffer.append(subQuery.toString(field));
+        }
+      } else {
+        buffer.append("null");
+      }
 
       if (i != clauses.size()-1)
         buffer.append(" ");