From e522a68ead8f87381918548c78d3615d18e26a65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Damian=20B=C3=BCchel?= <damian.buechel@let.ethz.ch>
Date: Wed, 22 Dec 2021 12:30:34 +0100
Subject: [PATCH] SEBWIN-524: Fixed possible deadlock in graceful termination
 mechanism for kiosk mode Disable Explorer Shell.

---
 SafeExamBrowser.WindowsApi/ExplorerShell.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/SafeExamBrowser.WindowsApi/ExplorerShell.cs b/SafeExamBrowser.WindowsApi/ExplorerShell.cs
index 8f89cff1..69764c33 100644
--- a/SafeExamBrowser.WindowsApi/ExplorerShell.cs
+++ b/SafeExamBrowser.WindowsApi/ExplorerShell.cs
@@ -104,7 +104,7 @@ namespace SafeExamBrowser.WindowsApi
 				nativeMethods.PostCloseMessageToShell();
 				logger.Debug("Waiting for explorer shell to terminate...");
 
-				while (nativeMethods.GetShellWindowHandle() != IntPtr.Zero)
+				for (var elapsed = 0; nativeMethods.GetShellWindowHandle() != IntPtr.Zero && elapsed < THREE_SECONDS; elapsed += 20)
 				{
 					Thread.Sleep(20);
 				}
@@ -141,7 +141,7 @@ namespace SafeExamBrowser.WindowsApi
 			var process = new System.Diagnostics.Process();
 			var taskkillPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.System), "taskkill.exe");
 
-			logger.Warn("Failed to gracefully terminate, attempting forceful termination...");
+			logger.Warn("Failed to gracefully terminate explorer shell, attempting forceful termination...");
 
 			process.StartInfo.Arguments = $"/F /PID {processId}";
 			process.StartInfo.CreateNoWindow = true;