Call to SharpWebview.Webview.Navigate fails on call to SingleOrDefault

[NickHarvey2]

When calling the Navigate method at application startup, GetWebViewAppContainerSid seems to find more than one AppContainer with a name matching microsoft.win32webviewhost_cw5n1h2txyewy, resulting in this error (this stacktrace is from the example DesktopApp, but the same happens with my own app)

~\webview_csharp\examples\DesktopApp> dotnet run
Unhandled exception. System.InvalidOperationException: Sequence contains more than one matching element
   at System.Linq.ThrowHelper.ThrowMoreThanOneMatchException()
   at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
   at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at SharpWebview.Loopback.GetWebViewAppContainerSid() in ~\webview_csharp\src\SharpWebview\Loopback.cs:line 31
   at SharpWebview.Loopback.IsWebViewLoopbackEnabled() in ~\webview_csharp\src\SharpWebview\Loopback.cs:line 21
   at SharpWebview.Webview.CheckLoopbackException(String url) in ~\webview_csharp\src\SharpWebview\Webview.cs:line 260
   at SharpWebview.Webview.Navigate(IWebviewContent webviewContent) in ~\webview_csharp\src\SharpWebview\Webview.cs:line 94
   at DesktopApp.Program.Main(String[] args) in ~\webview_csharp\examples\DesktopApp\Program.cs:line 24

I have checked that I added the loopback exemption

> CheckNetIsolation.exe LoopbackExempt -s

List Loopback Exempted AppContainers

[1] -----------------------------------------------------------------
    Name: AppContainer NOT FOUND
    SID:  S-1-15-2-490905099-2794809881-2632752266-3514030558-4166392763-3416490339-321513134

[2] -----------------------------------------------------------------
    Name: microsoft.win32webviewhost_cw5n1h2txyewy
    SID:  S-1-15-2-1310292540-1029022339-4008023048-2190398717-53961996-4257829345-603366646

OK.

(I actually tried clearing and re-adding the exemption a couple of times to no avail, because apparently the exemption list can become corrupted)

This is on Windows 11 21H2, using .NET 6.0.8 (SDK 6.0.400), WebView2 Runtime 105.0.1343.27

[NickHarvey2]

I did some console.log debugging in my local clone to log out the properties of the multiple matching AppContainers, and saw this:

displayName:       @{Microsoft.Win32WebViewHost_10.0.22000.1_neutral_neutral_cw5n1h2txyewy?ms-resource://Windows.Win32WebViewHost/resources/DisplayName}
appContainerName:  Microsoft.Win32WebViewHost_cw5n1h2txyewy
packageFullName:   Microsoft.Win32WebViewHost_10.0.22000.1_neutral_neutral_cw5n1h2txyewy
workingDirectory:  C:\Windows\SystemApps\Microsoft.Win32WebViewHost_cw5n1h2txyewy\
appContainerSid:   1867581628288
description:       @{Microsoft.Win32WebViewHost_10.0.22000.1_neutral_neutral_cw5n1h2txyewy?ms-resource://Windows.Win32WebViewHost/resources/Description}

displayName:       @{Microsoft.Win32WebViewHost_10.0.19041.1_neutral_neutral_cw5n1h2txyewy?ms-resource://Windows.Win32WebViewHost/resources/DisplayName}
appContainerName:  microsoft.win32webviewhost_cw5n1h2txyewy
packageFullName:   Microsoft.Win32WebViewHost_10.0.19041.1_neutral_neutral_cw5n1h2txyewy
workingDirectory:  C:\Windows\SystemApps\Microsoft.Win32WebViewHost_cw5n1h2txyewy\
appContainerSid:   1867581635808
description:       @{Microsoft.Win32WebViewHost_10.0.19041.1_neutral_neutral_cw5n1h2txyewy?ms-resource://Windows.Win32WebViewHost/resources/Description}

Noticed one of the appContainerNames is all lowercase and the other is mixed case, I removed the ToLower call when matching by name, and then the app appears to have run correctly. Then I changed the value of WebViewAppContainerName to match the mixed case appContainerName, and it also worked.

I'm new to Webview so a lot of this is beyond me and certainly don't know this well enough for a PR, but hopefully that is helpful? I'll keep looking at it, and if I learn enough to actually contribute a meaningful fix I'll submit a PR.

[NickHarvey2]

Okay, this may be simpler to fix than I thought. It seems like the Loopback class's only public method is there to check if the loopback is allowed before proceeding, if so I think the following would work (I'll submit a PR shortly)

         public bool IsWebViewLoopbackEnabled()
         {
-            var webViewSid = GetWebViewAppContainerSid();
+            var webViewSids = GetWebViewAppContainerSids();
             return GetAllAppContainerConfigs().Any(c =>
             {
                 ConvertSidToStringSid(c.Sid, out var currentSid);
-                return currentSid == webViewSid;
+                return webViewSids.Any(webViewSid => currentSid == webViewSid);
             });
         }

-        private string GetWebViewAppContainerSid()
+        private IEnumerable<string> GetWebViewAppContainerSids()
         {
-            var webviewAppContainer = GetAllAppContainers()
-                .SingleOrDefault(a => a.appContainerName.ToLower() == WebViewAppContainerName);
-            ConvertSidToStringSid(webviewAppContainer.appContainerSid, out var webViewSid);
-            return webViewSid;
+            return GetAllAppContainers()
+                .Where(a => a.appContainerName.ToLower() == WebViewAppContainerName)
+                .Select(firewallAppContainer => {
+                    ConvertSidToStringSid(firewallAppContainer.appContainerSid, out var webViewSid);
+                    return webViewSid;
+                });
         }