fix(cursor): close readable on null response for dead cursor

Author: mbroadst

lib/cursor.js

@@ -1081,6 +1081,13 @@ Cursor.prototype._read = function() {
       return self.emit('finish');
     }
 
+    if (result === null && self.isDead()) {
+      self.close();
+      self.emit('end');
+      self.emit('finish');
+      return;
+    }
+
     // If we provided a transformation method
     if(typeof self.s.streamOptions.transform == 'function' && result != null) {
       return self.push(self.s.streamOptions.transform(result));