Handle bad upgrade state without blocking the SDK (#46540)

Author: marcpopMSFT

src/Cli/dotnet/commands/InstallingWorkloadCommand.cs

@@ -254,7 +254,7 @@ private IEnumerable<ManifestVersionUpdate> InstallWorkloadSet(ITransactionContex
             PrintWorkloadSetTransition(workloadSetVersion);
             var workloadSet = _workloadInstaller.InstallWorkloadSet(context, workloadSetVersion);
 
-            return _workloadManifestUpdater.CalculateManifestUpdatesForWorkloadSet(workloadSet);
+            return workloadSet is null ? Enumerable.Empty<ManifestVersionUpdate>() : _workloadManifestUpdater.CalculateManifestUpdatesForWorkloadSet(workloadSet);
         }
 
         private void PrintWorkloadSetTransition(string newVersion)

src/Resolvers/Microsoft.NET.Sdk.WorkloadManifestReader/SdkDirectoryWorkloadManifestProvider.cs

@@ -539,7 +539,11 @@ static void AddWorkloadSetsForFeatureBand(Dictionary<string, WorkloadSet> availa
                     {
                         var workloadSetVersion = Path.GetFileName(workloadSetDirectory);
                         var workloadSet = WorkloadSet.FromWorkloadSetFolder(workloadSetDirectory, workloadSetVersion, featureBand);
-                        availableWorkloadSets[workloadSet.Version!] = workloadSet;
+
+                        if (workloadSet is not null)
+                        {
+                            availableWorkloadSets[workloadSet.Version!] = workloadSet;
+                        }
                     }
                 }
             }

src/Resolvers/Microsoft.NET.Sdk.WorkloadManifestReader/WorkloadSet.cs

@@ -81,7 +81,7 @@ public static WorkloadSet FromJson(string json, SdkFeatureBand defaultFeatureBan
 #endif
         }
 
-        public static WorkloadSet FromWorkloadSetFolder(string path, string workloadSetVersion, SdkFeatureBand defaultFeatureBand)
+        public static WorkloadSet? FromWorkloadSetFolder(string path, string workloadSetVersion, SdkFeatureBand defaultFeatureBand)
         {
             WorkloadSet? workloadSet = null;
             foreach (var jsonFile in Directory.GetFiles(path, "*.workloadset.json"))
@@ -107,7 +107,7 @@ public static WorkloadSet FromWorkloadSetFolder(string path, string workloadSetV
 
             if (workloadSet == null)
             {
-                throw new InvalidOperationException("No workload set information found in: " + path);
+                return null;
             }
 
             if (File.Exists(Path.Combine(path, "baseline.workloadset.json")))