Fix #1006

Fix threading issues and add missing null checks everywhere.

ILSpy/Languages/CSharpLanguage.cs

@@ -288,7 +288,7 @@ namespace ICSharpCode.ILSpy
 
 		void AddReferenceWarningMessage(AssemblyDefinition assembly, ITextOutput output)
 		{
-			var loadedAssembly = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().FirstOrDefault(la => la.GetAssemblyDefinitionAsync().Result == assembly);
+			var loadedAssembly = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().FirstOrDefault(la => la.GetAssemblyDefinitionOrNull() == assembly);
 			if (loadedAssembly == null || !loadedAssembly.LoadedAssemblyReferencesInfo.HasErrors)
 				return;
 			const string line1 = "Warning: Some assembly references could not be loaded. This might lead to incorrect decompilation of some parts,";

ILSpy/Languages/Language.cs

@@ -87,8 +87,9 @@ namespace ICSharpCode.ILSpy
 		public virtual void DecompileAssembly(LoadedAssembly assembly, ITextOutput output, DecompilationOptions options)
 		{
 			WriteCommentLine(output, assembly.FileName);
-			if (assembly.GetAssemblyDefinitionAsync().Result != null) {
-				var name = assembly.GetAssemblyDefinitionAsync().Result.Name;
+			var asm = assembly.GetAssemblyDefinitionOrNull();
+			if (asm != null) {
+				var name = asm.Name;
 				if (name.IsWindowsRuntime) {
 					WriteCommentLine(output, name.Name + " [WinRT]");
 				} else {

ILSpy/LoadedAssembly.cs

@@ -58,7 +58,7 @@ namespace ICSharpCode.ILSpy
 		/// </summary>
 		public async Task<string> GetTargetFrameworkIdAsync()
 		{
-			var assembly = await GetAssemblyDefinitionAsync();
+			var assembly = await GetAssemblyDefinitionAsync().ConfigureAwait(false);
 			return assembly?.DetectTargetFrameworkId() ?? string.Empty;
 		}
 
@@ -66,22 +66,43 @@ namespace ICSharpCode.ILSpy
 
 		/// <summary>
 		/// Gets the Cecil ModuleDefinition.
-		/// Can return null when there was a load error.
 		/// </summary>
 		public Task<ModuleDefinition> GetModuleDefinitionAsync()
 		{
 			return assemblyTask;
 		}
 
+		/// <summary>
+		/// Gets the Cecil ModuleDefinition.
+		/// Returns null in case of load errors.
+		/// </summary>
+		public ModuleDefinition GetModuleDefinitionOrNull()
+		{
+			try {
+				return GetModuleDefinitionAsync().Result;
+			} catch (Exception ex) {
+				System.Diagnostics.Trace.TraceError(ex.ToString());
+				return null;
+			}
+		}
+
 		/// <summary>
 		/// Gets the Cecil AssemblyDefinition.
-		/// Returns null when there was a load error; or when opening a netmodule.
 		/// </summary>
 		public async Task<AssemblyDefinition> GetAssemblyDefinitionAsync()
 		{
-			try {
-				var module = await assemblyTask;
+			var module = await assemblyTask.ConfigureAwait(false);
 			return module != null ? module.Assembly : null;
+		}
+
+		/// <summary>
+		/// Gets the Cecil AssemblyDefinition.
+		/// Returns null when there was a load error; or when opening a netmodule.
+		/// </summary>
+		public AssemblyDefinition GetAssemblyDefinitionOrNull()
+		{
+			try {
+				return GetAssemblyDefinitionAsync().Result;
 			} catch (Exception ex) {
 				System.Diagnostics.Trace.TraceError(ex.ToString());
 				return null;
@@ -97,7 +118,7 @@ namespace ICSharpCode.ILSpy
 		public string Text {
 			get {
 				if (IsLoaded && !HasLoadError) {
-					return String.Format("{0} ({1})", ShortName, GetAssemblyDefinitionAsync().Result.Name.Version);
+					return String.Format("{0} ({1})", ShortName, GetAssemblyDefinitionOrNull().Name.Version);
 				} else {
 					return ShortName;
 				}
@@ -196,14 +217,12 @@ namespace ICSharpCode.ILSpy
 			
 			public AssemblyDefinition Resolve(AssemblyNameReference name)
 			{
-				var node = parent.LookupReferencedAssembly(name);
-				return node != null ? node.GetAssemblyDefinitionAsync().Result : null;
+				return parent.LookupReferencedAssembly(name)?.GetAssemblyDefinitionOrNull();
 			}
 			
 			public AssemblyDefinition Resolve(AssemblyNameReference name, ReaderParameters parameters)
 			{
-				var node = parent.LookupReferencedAssembly(name);
-				return node != null ? node.GetAssemblyDefinitionAsync().Result : null;
+				return parent.LookupReferencedAssembly(name)?.GetAssemblyDefinitionOrNull();
 			}
 
 			public void Dispose()
@@ -243,7 +262,7 @@ namespace ICSharpCode.ILSpy
 			LoadedAssembly asm;
 			lock (loadingAssemblies) {
 				foreach (LoadedAssembly loaded in assemblyList.GetAssemblies()) {
-					var asmDef = loaded.GetAssemblyDefinitionAsync().Result;
+					var asmDef = loaded.GetAssemblyDefinitionOrNull();
 					if (asmDef != null && data.fullName.Equals(data.isWinRT ? asmDef.Name.Name : asmDef.FullName, StringComparison.OrdinalIgnoreCase)) {
 						return loaded;
 					}

ILSpy/TreeNodes/Analyzer/AnalyzedAttributeAppliedToTreeNode.cs

@@ -295,21 +295,24 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 			string requiredAssemblyFullName = asm.FullName;
 
-			IEnumerable<LoadedAssembly> assemblies = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().Where(assy => assy.GetAssemblyDefinitionAsync().Result != null);
+			IEnumerable<LoadedAssembly> assemblies = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().Where(assy => assy.GetAssemblyDefinitionOrNull() != null);
 
 			foreach (var assembly in assemblies) {
 				ct.ThrowIfCancellationRequested();
 				bool found = false;
-				foreach (var reference in assembly.GetAssemblyDefinitionAsync().Result.MainModule.AssemblyReferences) {
+				var module = assembly.GetModuleDefinitionOrNull();
+				if (module == null)
+					continue;
+				foreach (var reference in module.AssemblyReferences) {
 					if (requiredAssemblyFullName == reference.FullName) {
 						found = true;
 						break;
 					}
 				}
 				if (found) {
-					var typeref = GetScopeTypeReferenceInAssembly(assembly.GetAssemblyDefinitionAsync().Result);
+					var typeref = GetScopeTypeReferenceInAssembly(module.Assembly);
 					if (typeref != null)
-						yield return new Tuple<AssemblyDefinition, TypeReference>(assembly.GetAssemblyDefinitionAsync().Result, typeref);
+						yield return new Tuple<AssemblyDefinition, TypeReference>(module.Assembly, typeref);
 				}
 			}
 		}
@@ -333,10 +336,13 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 					foreach (var assembly in assemblies) {
 						ct.ThrowIfCancellationRequested();
+						var module = assembly.GetModuleDefinitionOrNull();
+						if (module == null)
+							continue;
 						if (friendAssemblies.Contains(assembly.ShortName)) {
-							var typeref = GetScopeTypeReferenceInAssembly(assembly.GetAssemblyDefinitionAsync().Result);
+							var typeref = GetScopeTypeReferenceInAssembly(module.Assembly);
 							if (typeref != null) {
-								yield return new Tuple<AssemblyDefinition, TypeReference>(assembly.GetAssemblyDefinitionAsync().Result, typeref);
+								yield return new Tuple<AssemblyDefinition, TypeReference>(module.Assembly, typeref);
 							}
 						}
 					}

ILSpy/TreeNodes/Analyzer/ScopedWhereUsedAnalyzer.cs

@@ -254,19 +254,22 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 			string requiredAssemblyFullName = asm.FullName;
 
-			IEnumerable<LoadedAssembly> assemblies = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().Where(assy => assy.GetAssemblyDefinitionAsync().Result != null);
+			IEnumerable<LoadedAssembly> assemblies = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().Where(assy => assy.GetAssemblyDefinitionOrNull() != null);
 
 			foreach (var assembly in assemblies) {
 				ct.ThrowIfCancellationRequested();
 				bool found = false;
-				foreach (var reference in assembly.GetAssemblyDefinitionAsync().Result.MainModule.AssemblyReferences) {
+				var module = assembly.GetModuleDefinitionOrNull();
+				if (module == null)
+					continue;
+				foreach (var reference in module.AssemblyReferences) {
 					if (requiredAssemblyFullName == reference.FullName) {
 						found = true;
 						break;
 					}
 				}
-				if (found && AssemblyReferencesScopeType(assembly.GetAssemblyDefinitionAsync().Result))
-					yield return assembly.GetAssemblyDefinitionAsync().Result;
+				if (found && AssemblyReferencesScopeType(module.Assembly))
+					yield return module.Assembly;
 			}
 		}
 
@@ -289,8 +292,12 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 					foreach (var assembly in assemblies) {
 						ct.ThrowIfCancellationRequested();
-						if (friendAssemblies.Contains(assembly.ShortName) && AssemblyReferencesScopeType(assembly.GetAssemblyDefinitionAsync().Result)) {
-							yield return assembly.GetAssemblyDefinitionAsync().Result;
+						if (friendAssemblies.Contains(assembly.ShortName)) {
+							var module = assembly.GetModuleDefinitionOrNull();
+							if (module == null)
+								continue;
+							if (AssemblyReferencesScopeType(module.Assembly))
+								yield return module.Assembly;
 						}
 					}
 				}

ILSpy/TreeNodes/AssemblyListTreeNode.cs

@@ -197,7 +197,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 				return null;
 			App.Current.Dispatcher.VerifyAccess();
 			foreach (AssemblyTreeNode node in this.Children) {
-				if (node.LoadedAssembly.IsLoaded && node.LoadedAssembly.GetAssemblyDefinitionAsync().Result == asm)
+				if (node.LoadedAssembly.IsLoaded && node.LoadedAssembly.GetAssemblyDefinitionOrNull() == asm)
 					return node;
 			}
 			return null;

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -97,8 +97,8 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 				if (tooltip == null && assembly.IsLoaded) {
 					tooltip = new TextBlock();
-					var module = assembly.GetModuleDefinitionAsync().Result;
-					if (assembly.GetAssemblyDefinitionAsync().Result != null) {
+					var module = assembly.GetModuleDefinitionOrNull();
+					if (module.Assembly != null) {
 						tooltip.Inlines.Add(new Bold(new Run("Name: ")));
 						tooltip.Inlines.Add(new Run(module.Assembly.FullName));
 						tooltip.Inlines.Add(new LineBreak());