From e18dcd1bea388527bdbf8e9c11edfda6d9f4313e Mon Sep 17 00:00:00 2001
From: Sam El-Husseini <sam.elhusseini@gmail.com>
Date: Wed, 9 Oct 2019 16:08:23 -0700
Subject: [PATCH] bringToFront optimization for large workspaces (#3214)

* bringToFront optimization for large workspaces
---
 core/block_svg.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/core/block_svg.js b/core/block_svg.js
index eaf20126d..7c1ef782a 100644
--- a/core/block_svg.js
+++ b/core/block_svg.js
@@ -1375,7 +1375,12 @@ Blockly.BlockSvg.prototype.bringToFront = function() {
   var block = this;
   do {
     var root = block.getSvgRoot();
-    root.parentNode.appendChild(root);
+    var parent = root.parentNode;
+    var childNodes = parent.childNodes;
+    // Avoid moving the block if it's already at the bottom.
+    if (childNodes[childNodes.length - 1] !== root) {
+      parent.appendChild(root);
+    }
     block = block.getParent();
   } while (block);
 };