From 8656363a7adbbc7a3aad17eff12f3e4dd2c6afff Mon Sep 17 00:00:00 2001
From: dbuechel <damian.buechel@let.ethz.ch>
Date: Wed, 8 May 2019 13:53:38 +0200
Subject: [PATCH] SEBWIN-325: Only update the favicon if it really exists.

---
 .../BrowserApplicationInstance.cs                | 16 +++++++++++++---
 .../SafeExamBrowser.Browser.csproj               |  1 +
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/SafeExamBrowser.Browser/BrowserApplicationInstance.cs b/SafeExamBrowser.Browser/BrowserApplicationInstance.cs
index f14f20a3..2e7ee6eb 100644
--- a/SafeExamBrowser.Browser/BrowserApplicationInstance.cs
+++ b/SafeExamBrowser.Browser/BrowserApplicationInstance.cs
@@ -7,6 +7,7 @@
  */
 
 using System;
+using System.Net.Http;
 using SafeExamBrowser.Browser.Events;
 using SafeExamBrowser.Browser.Handlers;
 using SafeExamBrowser.Contracts.Applications;
@@ -28,6 +29,7 @@ namespace SafeExamBrowser.Browser
 		private AppConfig appConfig;
 		private IBrowserControl control;
 		private IBrowserWindow window;
+		private HttpClient httpClient;
 		private bool isMainInstance;
 		private IMessageBox messageBox;
 		private IModuleLogger logger;
@@ -64,6 +66,7 @@ namespace SafeExamBrowser.Browser
 		{
 			this.appConfig = appConfig;
 			this.Id = id;
+			this.httpClient = new HttpClient();
 			this.isMainInstance = isMainInstance;
 			this.messageBox = messageBox;
 			this.logger = logger;
@@ -133,10 +136,17 @@ namespace SafeExamBrowser.Browser
 
 		private void DisplayHandler_FaviconChanged(string uri)
 		{
-			var icon = new BrowserIconResource(uri);
+			var request = new HttpRequestMessage(HttpMethod.Head, uri);
+			var response = httpClient.SendAsync(request).ContinueWith(task =>
+			{
+				if (task.IsCompleted && task.Result.IsSuccessStatusCode)
+				{
+					var icon = new BrowserIconResource(uri);
 
-			IconChanged?.Invoke(icon);
-			window.UpdateIcon(icon);
+					IconChanged?.Invoke(icon);
+					window.UpdateIcon(icon);
+				}
+			});
 		}
 
 		private void DownloadHandler_ConfigurationDownloadRequested(string fileName, DownloadEventArgs args)
diff --git a/SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj b/SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj
index c4b7a1a1..580ece37 100644
--- a/SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj
+++ b/SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj
@@ -59,6 +59,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
+    <Reference Include="System.Net.Http" />
     <Reference Include="System.Windows.Forms" />
     <Reference Include="Microsoft.CSharp" />
   </ItemGroup>