Remove unauthenticated sources to avoid keep hitting the same failing…

… source(s) for all packages

src/NuPU/UpdateCommand.cs

@@ -11,6 +11,7 @@
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Xml;
@@ -45,7 +46,7 @@ public override async Task<int> ExecuteAsync(CommandContext context, UpdateComma
             foreach (var csProjFile in csProjFiles.Where(f => !Ignored(f, ignoreDirs)))
             {
                 var settings = Settings.LoadDefaultSettings(csProjFile.Directory.FullName);
-                var enabledSources = SettingsUtility.GetEnabledSources(settings);
+                var enabledSources = SettingsUtility.GetEnabledSources(settings).ToList();
                 AnsiConsole.MarkupLine($"Analyzing [yellow]{csProjFile.FullName}[/]");
                 var packages = new List<Package>();
                 using (var fileStream = File.OpenRead(csProjFile.FullName))
@@ -95,6 +96,7 @@ public override async Task<int> ExecuteAsync(CommandContext context, UpdateComma
                     AnsiConsole.Markup(package.Id);
 
                     var showUpToDate = true;
+                    var sourcesToDelete = new List<PackageSource>();
                     foreach (var source in enabledSources)
                     {
                         var repository = new SourceRepository(source, Repository.Provider.GetCoreV3());
@@ -172,16 +174,32 @@ public override async Task<int> ExecuteAsync(CommandContext context, UpdateComma
                                 }
                             }
                         }
+                        catch (FatalProtocolException ex) when (IsAuthenticationError(ex))
+                        {
+                            sourcesToDelete.Add(source);
+                        }
                         catch { }
                     }
 
+                    // If we had any unauthenticated sources we remove them to avoid requesting them for the next package.
+                    foreach (var sourceToDelete in sourcesToDelete)
+                    {
+                        if (enabledSources.Contains(sourceToDelete)) enabledSources.Remove(sourceToDelete);
+                    }
+
                     if (showUpToDate) AnsiConsole.MarkupLine(UpToDate);
                 }
             }
 
             return 0;
         }
 
+        private static bool IsAuthenticationError(FatalProtocolException ex)
+        {
+            var baseException = ex.GetBaseException() as HttpRequestException;
+            return baseException == null ? false : baseException.StatusCode == System.Net.HttpStatusCode.Unauthorized;
+        }
+
         private bool Ignored(FileInfo fileInfo, List<string> ignoreDirs)
         {
             if (ignoreDirs.Count == 0) return false;