[OOBE] Get "What's New" behind authenticated proxy and strict firewall. (#18695)

* Attempt to get username and password for proxy authentication. We should not use it.

* Using default credentials for system proxy authentication.

src/settings-ui/Settings.UI/OOBE/Views/OobeWhatsNew.xaml

@@ -31,15 +31,7 @@
                     TextWrapping="Wrap" />
             </HyperlinkButton>
         </StackPanel>
-        <ScrollViewer Grid.Row="1" VerticalScrollBarVisibility="Auto">
+        <muxc:InfoBar
-            <Grid Margin="32,24,32,24">
-                <muxc:ProgressRing Grid.Row="1"
-                x:Name="LoadingProgressRing"
-                IsIndeterminate="True"
-                VerticalAlignment="Center"
-                HorizontalAlignment="Center"
-                Visibility="Visible"/>
-                <muxc:InfoBar
                 Severity="Error"
                 x:Name="ErrorInfoBar"
                 Grid.Row="1"
@@ -49,9 +41,26 @@
                 IsClosable="False"
                 IsOpen="True"
                 IsTabStop="True" />
+        <muxc:InfoBar
+            x:Name="ProxyWarningInfoBar"
+            Severity="Warning"
+            Grid.Row="1"
+            Visibility="Collapsed"
+            x:Uid="Oobe_WhatsNew_ProxyAuthenticationWarning"
+            VerticalAlignment="Top"
+            IsClosable="False"
+            IsOpen="True"
+            IsTabStop="True" />
+        <ScrollViewer Grid.Row="1" VerticalScrollBarVisibility="Auto">
+            <Grid Margin="32,24,32,24">
+                <muxc:ProgressRing
+                x:Name="LoadingProgressRing"
+                IsIndeterminate="True"
+                VerticalAlignment="Center"
+                HorizontalAlignment="Center"
+                Visibility="Visible"/>
                 <toolkitcontrols:MarkdownTextBlock x:Name="ReleaseNotesMarkdown"
                                                    Visibility="Collapsed"
-                                                   Grid.Row="1"
                                                    Header1FontSize="20"
                                                    Header2FontSize="17"
                                                    Header2FontWeight="SemiBold"

src/settings-ui/Settings.UI/OOBE/Views/OobeWhatsNew.xaml.cs

@@ -6,6 +6,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Net;
 using System.Net.Http;
 using System.Text;
 using System.Text.Json;
@@ -18,7 +19,6 @@ using Microsoft.PowerToys.Settings.UI.OOBE.Enums;
 using Microsoft.PowerToys.Settings.UI.OOBE.ViewModel;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Navigation;
-using Windows.UI.Core;
 
 namespace Microsoft.PowerToys.Settings.UI.OOBE.Views
 {
@@ -55,14 +55,21 @@ namespace Microsoft.PowerToys.Settings.UI.OOBE.Views
         private static async Task<string> GetReleaseNotesMarkdown()
         {
             string releaseNotesJSON = string.Empty;
-            using (HttpClient getReleaseInfoClient = new HttpClient())
-            {
-                // GitHub APIs require sending an user agent
-                // https://docs.github.com/en/rest/overview/resources-in-the-rest-api#user-agent-required
-                getReleaseInfoClient.DefaultRequestHeaders.TryAddWithoutValidation("User-Agent", "PowerToys");
-                releaseNotesJSON = await getReleaseInfoClient.GetStringAsync("https://api.github.com/repos/microsoft/PowerToys/releases");
-            }
 
+            // Let's use system proxy
+            using var proxyClientHandler = new HttpClientHandler
+            {
+                DefaultProxyCredentials = CredentialCache.DefaultCredentials,
+                Proxy = WebRequest.GetSystemWebProxy(),
+                PreAuthenticate = true,
+            };
+
+            using var getReleaseInfoClient = new HttpClient(proxyClientHandler);
+
+            // GitHub APIs require sending an user agent
+            // https://docs.github.com/en/rest/overview/resources-in-the-rest-api#user-agent-required
+            getReleaseInfoClient.DefaultRequestHeaders.TryAddWithoutValidation("User-Agent", "PowerToys");
+            releaseNotesJSON = await getReleaseInfoClient.GetStringAsync("https://api.github.com/repos/microsoft/PowerToys/releases");
             IList<PowerToysReleaseInfo> releases = JsonSerializer.Deserialize<IList<PowerToysReleaseInfo>>(releaseNotesJSON);
 
             // Get the latest releases
@@ -83,23 +90,45 @@ namespace Microsoft.PowerToys.Settings.UI.OOBE.Views
             return releaseNotesHtmlBuilder.ToString();
         }
 
-        private async void Page_Loaded(object sender, Microsoft.UI.Xaml.RoutedEventArgs e)
+        private async Task Reload()
         {
             try
             {
                 string releaseNotesMarkdown = await GetReleaseNotesMarkdown();
 
+                ProxyWarningInfoBar.Visibility = Microsoft.UI.Xaml.Visibility.Collapsed;
+                ErrorInfoBar.Visibility = Microsoft.UI.Xaml.Visibility.Collapsed;
+
                 ReleaseNotesMarkdown.Text = releaseNotesMarkdown;
                 ReleaseNotesMarkdown.Visibility = Microsoft.UI.Xaml.Visibility.Visible;
                 LoadingProgressRing.Visibility = Microsoft.UI.Xaml.Visibility.Collapsed;
             }
+            catch (HttpRequestException httpEx)
+            {
+                Logger.LogError("Exception when loading the release notes", httpEx);
+                if (httpEx.Message.Contains("407", StringComparison.CurrentCulture))
+                {
+                    ProxyWarningInfoBar.Visibility = Microsoft.UI.Xaml.Visibility.Visible;
+                }
+                else
+                {
+                    ErrorInfoBar.Visibility = Microsoft.UI.Xaml.Visibility.Visible;
+                }
+            }
             catch (Exception ex)
             {
                 Logger.LogError("Exception when loading the release notes", ex);
-
-                LoadingProgressRing.Visibility = Microsoft.UI.Xaml.Visibility.Collapsed;
                 ErrorInfoBar.Visibility = Microsoft.UI.Xaml.Visibility.Visible;
             }
+            finally
+            {
+                LoadingProgressRing.Visibility = Microsoft.UI.Xaml.Visibility.Collapsed;
+            }
+        }
+
+        private async void Page_Loaded(object sender, Microsoft.UI.Xaml.RoutedEventArgs e)
+        {
+            await Reload();
         }
 
         /// <inheritdoc/>

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -1488,6 +1488,12 @@ From there, simply click on one of the supported files in the File Explorer and
   <data name="Oobe_WhatsNew_LoadingError.Message" xml:space="preserve">
     <value>Please check your internet connection.</value>
   </data>
+  <data name="Oobe_WhatsNew_ProxyAuthenticationWarning.Title" xml:space="preserve">
+    <value>Couldn't load the release notes.</value>
+  </data>
+  <data name="Oobe_WhatsNew_ProxyAuthenticationWarning.Message" xml:space="preserve">
+    <value>Your proxy server requires authentication.</value>
+  </data>
   <data name="Oobe_WhatsNew_DetailedReleaseNotesLink.Text" xml:space="preserve">
     <value>See more detailed release notes on GitHub</value>
     <comment>Don't loc "GitHub", it's the name of a product</comment>