From f300dc7e40eb1000ce8a759194707091cce71303 Mon Sep 17 00:00:00 2001
From: Shad Storhaug <shad@shadstorhaug.com>
Date: Sun, 2 Nov 2014 14:34:35 +0700
Subject: [PATCH] Fixes #369, canonical URL and canonical key validation always
 throws an exception when using .NET Attributes.

---
 src/MvcSiteMapProvider/MvcSiteMapProvider/SiteMapNode.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/MvcSiteMapProvider/MvcSiteMapProvider/SiteMapNode.cs b/src/MvcSiteMapProvider/MvcSiteMapProvider/SiteMapNode.cs
index 0aabf694..872874a0 100644
--- a/src/MvcSiteMapProvider/MvcSiteMapProvider/SiteMapNode.cs
+++ b/src/MvcSiteMapProvider/MvcSiteMapProvider/SiteMapNode.cs
@@ -465,7 +465,7 @@ public override string CanonicalKey
             {
                 if (!this.canonicalKey.Equals(value))
                 {
-                    if (!string.IsNullOrEmpty(this.canonicalUrl))
+                    if (!string.IsNullOrEmpty(value) && !string.IsNullOrEmpty(this.canonicalUrl))
                     {
                         throw new ArgumentException(string.Format(Resources.Messages.SiteMapNodeCanonicalValueAlreadySet, "CanonicalKey"), "CanonicalKey");
                     }
@@ -497,7 +497,7 @@ public override string CanonicalUrl
             {
                 if (!this.canonicalUrl.Equals(value))
                 {
-                    if (!string.IsNullOrEmpty(this.canonicalKey))
+                    if (!string.IsNullOrEmpty(value) && !string.IsNullOrEmpty(this.canonicalKey))
                     {
                         throw new ArgumentException(string.Format(Resources.Messages.SiteMapNodeCanonicalValueAlreadySet, "CanonicalUrl"), "CanonicalUrl");
                     }