From 6c4b288961f8577d7a395fc596114b7ece129767 Mon Sep 17 00:00:00 2001
From: Tatsuya Yamaguchi <susumu-336@hotmail.co.jp>
Date: Wed, 1 Mar 2023 10:42:14 +0900
Subject: [PATCH] GMapProvider: add Empty check for RefererUrl

---
 ExtLibs/GMap.NET.Core/GMap.NET.MapProviders/GMapProvider.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ExtLibs/GMap.NET.Core/GMap.NET.MapProviders/GMapProvider.cs b/ExtLibs/GMap.NET.Core/GMap.NET.MapProviders/GMapProvider.cs
index 578c87537d..61bef78e5e 100644
--- a/ExtLibs/GMap.NET.Core/GMap.NET.MapProviders/GMapProvider.cs
+++ b/ExtLibs/GMap.NET.Core/GMap.NET.MapProviders/GMapProvider.cs
@@ -402,7 +402,8 @@ protected PureImage GetTileImageUsingHttp(string url)
             {
                 request.Headers.Add("User-Agent", UserAgent);
                 request.Headers.Add("Accept", requestAccept);
-                request.Headers.Add("Referer", RefererUrl);
+                if (!string.IsNullOrEmpty(RefererUrl))
+                    request.Headers.Add("Referer", RefererUrl);
 
                 MemoryStream data = Task.Run(async () =>
                 {