fix array index when empty array SERVER-1082

1 files changed, 26 insertions, 14 deletions

diff --git a/db/index.cpp b/db/index.cpp
index 5ec2658dfec..81c84ff2f99 100644
--- a/db/index.cpp
+++ b/db/index.cpp
@@ -206,6 +206,8 @@ namespace mongo {
                 break;
             }
         }
+        
+        bool insertArrayNull = false;
 
         if ( allFound ) {
             if ( arrElt.eoo() ) {
@@ -231,29 +233,39 @@ namespace mongo {
                     }
                 }
                 else if ( fixed.size() > 1 ){
-                    // x : [] - need to insert undefined
-                    BSONObjBuilder b(_sizeTracker);
-                    for( unsigned j = 0; j < fixed.size(); ++j ) {
-                        if ( j == arrIdx )
-                            b.appendUndefined( "" );
-                        else
-                            b.appendAs( fixed[ j ], "" );
-                    }
-                    keys.insert( b.obj() );
+                    insertArrayNull = true;
                 }
             }
         } else {
             // nonterminal array element to expand, so recurse
             assert( !arrElt.eoo() );
             BSONObjIterator i( arrElt.embeddedObject() );
-            while( i.more() ) {
-                BSONElement e = i.next();
-                if ( e.type() == Object )
-                    _getKeys( fieldNames, fixed, e.embeddedObject(), keys );
+            if ( i.more() ){
+                while( i.more() ) {
+                    BSONElement e = i.next();
+                    if ( e.type() == Object )
+                        _getKeys( fieldNames, fixed, e.embeddedObject(), keys );
+                }
+            }
+            else {
+                insertArrayNull = true;
             }
         }
-    }
+        
+        if ( insertArrayNull ){
+            // x : [] - need to insert undefined
+            BSONObjBuilder b(_sizeTracker);
+            for( unsigned j = 0; j < fixed.size(); ++j ) {
+                if ( j == arrIdx )
+                    b.appendUndefined( "" );
+                else
+                    b.appendAs( fixed[ j ], "" );
+            }
+            keys.insert( b.obj() );
+        }
 
+    }
+    
     /* Pull out the relevant key objects from obj, so we
        can index them.  Note that the set is multiple elements
        only when it's a "multikey" array.