From 73417b831725262c4a226fc3784a3ac7f5a23562 Mon Sep 17 00:00:00 2001
From: Neil Fraser <fraser@google.com>
Date: Wed, 14 Feb 2018 11:22:55 -0800
Subject: [PATCH] Reduce size of XML by omitting empty variable tag.

---
 core/xml.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/core/xml.js b/core/xml.js
index e99a95a58..baf575b75 100644
--- a/core/xml.js
+++ b/core/xml.js
@@ -42,8 +42,10 @@ goog.require('goog.dom');
  */
 Blockly.Xml.workspaceToDom = function(workspace, opt_noId) {
   var xml = goog.dom.createDom('xml');
-  xml.appendChild(Blockly.Xml.variablesToDom(
-      Blockly.Variables.allUsedVarModels(workspace)));
+  var variables = Blockly.Variables.allUsedVarModels(workspace);
+  if (variables.length) {
+    xml.appendChild(Blockly.Xml.variablesToDom(variables));
+  }
   var blocks = workspace.getTopBlocks(true);
   for (var i = 0, block; block = blocks[i]; i++) {
     xml.appendChild(Blockly.Xml.blockToDomWithXY(block, opt_noId));