From 28ba66d98d4980a27a29444a62f88430c20544cf Mon Sep 17 00:00:00 2001
From: Brett Zamir <brettz9@yahoo.com>
Date: Mon, 28 May 2018 20:42:37 +0800
Subject: [PATCH] - Optimization: For `setSvgString`, if element content is not
 SVG, return `false` earlier (Fixes #152); thanks iuyiuy!

---
 editor/svgcanvas.js | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/editor/svgcanvas.js b/editor/svgcanvas.js
index 2c388813..e7d5adb2 100644
--- a/editor/svgcanvas.js
+++ b/editor/svgcanvas.js
@@ -3632,22 +3632,23 @@ const convertToGroup = this.convertToGroup = function (elem) {
   }
 };
 
-//
-// Function: setSvgString
-// This function sets the current drawing as the input SVG XML.
-//
-// Parameters:
-// xmlString - The SVG as XML text.
-// preventUndo - Boolean (defaults to false) indicating if we want to do the
-// changes without adding them to the undo stack - e.g. for initializing a
-// drawing on page load.
-//
-// Returns:
-// This function returns false if the set was unsuccessful, true otherwise.
+/**
+* This function sets the current drawing as the input SVG XML.
+* @param {String} xmlString - The SVG as XML text.
+* @param {Boolean} [preventUndo=false] - Indicates if we want to do the
+* changes without adding them to the undo stack - e.g. for initializing a
+* drawing on page load.
+* @returns {Boolean} This function returns false if the set was
+*     unsuccessful, true otherwise.
+*/
 this.setSvgString = function (xmlString, preventUndo) {
   try {
     // convert string into XML document
     const newDoc = text2xml(xmlString);
+    if (newDoc.firstElementChild &&
+      newDoc.firstElementChild.namespaceURI !== NS.SVG) {
+      return false;
+    }
 
     this.prepareSvg(newDoc);