Visual Studio crashes when pasting number ending with space into PR search box

[jcansdale]

Version

• GitHub Extension for Visual Studio version: 2.5.6 (dev)
• Visual Studio version: 2017

What happened

Steps to Reproduce

1. Open GitHub based solution in Visual Studio
2. Open GitHub pane
3. Paste a number with trailing white-space into search box (e.g "156 ")
4. Visual Studio crashes and quits

Log file:

The Windows Event Viewer contains the following under Application > .NET Runtime:

Application: devenv.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.InvalidOperationException
   at Microsoft.VisualStudio.Platform.WindowManagement.WindowSearchHost.StartSearch(Microsoft.VisualStudio.Shell.Interop.IVsSearchQuery, System.Action)
   at Microsoft.VisualStudio.Platform.WindowManagement.WindowSearchHost+<>c__DisplayClass42_0.<SearchAsync>b__0()
   at Microsoft.VisualStudio.Shell.ThreadHelper.Invoke(System.Action)
   at Microsoft.VisualStudio.Platform.WindowManagement.WindowSearchHost.SearchAsync(Microsoft.VisualStudio.Shell.Interop.IVsSearchQuery)
   at GitHub.VisualStudio.UI.GitHubPane.UpdateSearchHost(Boolean, System.String)
   at GitHub.VisualStudio.UI.GitHubPane.<set_View>b__6_2(System.Tuple`2<Boolean,System.String>)
   at System.Reactive.AnonymousSafeObserver`1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].OnNext(System.__Canon)
   at System.Reactive.ScheduledObserver`1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].Run(System.Object, System.Action`1<System.Object>)
   at System.Reactive.Concurrency.Scheduler+<>c__DisplayClass65_0`1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].<InvokeRec1>b__0(System.__Canon)
   at System.Reactive.Concurrency.Scheduler.InvokeRec1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]](System.Reactive.Concurrency.IScheduler, Pair`2<System.__Canon,System.Action`2<System.__Canon,System.Action`1<System.__Canon>>>)
   at System.Reactive.Concurrency.DispatcherScheduler+<>c__DisplayClass12_0`1[[System.Reactive.Concurrency.Scheduler+Pair`2[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], System.Reactive.Core, Version=2.2.5.0, Culture=neutral, PublicKeyToken=62aa029873c516b4]].<Schedule>b__0()
   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.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(System.Object)
   at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(System.Object)
   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 MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext, 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)

VisualStudio/src/GitHub.VisualStudio/UI/GitHubPane.cs

Lines 166 to 177 in fdca558

	void UpdateSearchHost(bool enabled, string query)
	{
	if (SearchHost != null)
	{
	SearchHost.IsEnabled = enabled;
	if (SearchHost.SearchQuery?.SearchString != query)
	{
	SearchHost.SearchAsync(query != null ? new SearchQuery(query) : null);
	}
	}
	}

Research

Replacing the above method with the following appears to fix the crash.

        void UpdateSearchHost(bool enabled, string query)
        {
            if (SearchHost != null)
            {
                SearchHost.IsEnabled = enabled;

                var searchString = SearchHost.SearchQuery?.SearchString;
                if (searchString?.Trim() != query?.Trim())
                {
                    SearchHost.SearchAsync(query != null ? new SearchQuery(query) : null);
                }
            }
        }

Here is Microsoft.VisualStudio.Platform.WindowManagement.WindowSearchHost.SearchAsync from Microsoft.VisualStudio.Platform.WindowManagement, Version=15.0.0.0:

I noticed that searchString is often "" rather than null. This causes SearchAsync to be cleared multiple times in a row. I don't know if this is potentially an issue. It doesn't cause crashes anyway!