diff --git a/solr/solrj/src/java/org/apache/solr/common/SolrInputDocument.java b/solr/solrj/src/java/org/apache/solr/common/SolrInputDocument.java
index 0fdf78b7a39..f84a4baf80f 100644
--- a/solr/solrj/src/java/org/apache/solr/common/SolrInputDocument.java
+++ b/solr/solrj/src/java/org/apache/solr/common/SolrInputDocument.java
@@ -20,7 +20,6 @@
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -43,12 +42,10 @@ public class SolrInputDocument implements Map<String,SolrInputField>, Iterable<S
   
   public SolrInputDocument() {
     _fields = new LinkedHashMap<String,SolrInputField>();
-    _childDocuments = new ArrayList<SolrInputDocument>();
   }
   
   public SolrInputDocument(Map<String,SolrInputField> fields) {
     _fields = fields;
-    _childDocuments = new ArrayList<SolrInputDocument>();
   }
   
   /**
@@ -198,7 +195,13 @@ public void setDocumentBoost(float documentBoost) {
   @Override
   public String toString()
   {
-    return "SolrInputDocument(fields: " + _fields.values() + ", childs: " + _childDocuments + ")";
+    String children;
+    if (hasChildDocuments()) {
+      children = ", children: " + _childDocuments;
+    } else {
+      children = "";
+    }
+    return "SolrInputDocument(fields: " + _fields.values() + children + ")";
   }
   
   public SolrInputDocument deepCopy() {
@@ -208,11 +211,13 @@ public SolrInputDocument deepCopy() {
       clone._fields.put(fieldEntry.getKey(), fieldEntry.getValue().deepCopy());
     }
     clone._documentBoost = _documentBoost;
-    
-    clone._childDocuments = new ArrayList<SolrInputDocument>(_childDocuments.size());
-    for (SolrInputDocument child : _childDocuments) {
-      clone._childDocuments.add(child.deepCopy());  
-    }    
+
+    if (hasChildDocuments()) {
+      clone._childDocuments = new ArrayList<SolrInputDocument>(_childDocuments.size());
+      for (SolrInputDocument child : _childDocuments) {
+        clone._childDocuments.add(child.deepCopy());
+      }
+    }
     
     return clone;
   }
@@ -277,11 +282,14 @@ public Collection<SolrInputField> values() {
   }
   
   public void addChildDocument(SolrInputDocument child) {
+    if (!hasChildDocuments()) {
+      _childDocuments = new ArrayList<SolrInputDocument>();
+    }
     _childDocuments.add(child);
   }
   
-  public void addChildDocuments(Collection<SolrInputDocument> childs) {
-    for (SolrInputDocument child : childs) {
+  public void addChildDocuments(Collection<SolrInputDocument> children) {
+    for (SolrInputDocument child : children) {
       addChildDocument(child);
     }
   }
@@ -291,7 +299,6 @@ public List<SolrInputDocument> getChildDocuments() {
   }
   
   public boolean hasChildDocuments() {
-    boolean isEmpty = (_childDocuments == null || _childDocuments.isEmpty());
-    return !isEmpty;
+    return _childDocuments != null;
   }
 }