Crash when shutting down Windows 8.1 if Desktop was never opened

[HellBrick]

This happens on a Windows 8.1 laptop that launches Start screen instead of Desktop by default. If Switcheroo is set to launched automatically and Desktop (or any classic Desktop software for that matter) is never opened, Switcheroo crashes with 'The instruction at %address% references memory at 0x00000008' alert when you try to shut down the system. Apparently, something goes wrong when the system attempts to gracefully terminate the app.

I've found this in the event viewer, even though it doesn't look very helpful:

Application: switcheroo.exe Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: System.NullReferenceException Stack: at System.Windows.Window.InternalClose(Boolean, Boolean) at System.Windows.Application.DoShutdown() at System.Windows.Application.ShutdownImpl() at System.Windows.Application.ShutdownCallback(System.Object) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef) at MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate) at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr) at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef) at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef) at System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame) at System.Windows.Application.RunDispatcher(System.Object) at System.Windows.Application.RunInternal(System.Windows.Window) at Switcheroo.Program.Main()

[kvakulo]

Thanks for the report @HellBrick!

Actually I just experienced the same bug, but it happened even from Desktop.

It seems like it was caused by:

1. The latest Windows Update, or
2. Because of installing .NET 4.5.2

Did you by any chance just install the latest updates or installed .NET 4.5.2?

I did both those things at the same time, so I'm not sure which one is now causing Switcheroo to crash on shutdown. Maybe you have a clue? :)

/Regin

[HellBrick]

This is really weird, because I have a 100% repro: if I open Desktop just once, Switcheroo doesn't crash; if I never open Desktop, it crashes.

Switcheroo actually have been behaving like this for a while now, probably ever since I had installed it on that laptop (I just kept forgetting to submit the issue), so this is unlikely to be connected to the latest updates.

I do have 4.5.2 installed, but I also have it installed on my main PC, where I have never seen this crash. The main PC boots straight to the Desktop though, which seems to be in line with my repro.

Based on the info we currently have, I've no idea what's going on. I'd try analyzing the crash dump or just looking very carefully at the things that happen when the application shuts down.

[kvakulo]

Really useful feedback! Based on it I think I've might identified the issue: If Switcheroo is shutdown without having been activated, then an uninitialized value is being disposed. Does this commit fix the issue for you?

/ Regin

[HellBrick]

Yep, the fix works - I can't reproduce the issue anymore =)

[kvakulo]

Hurray! :D

/ Regin