Fix #1233: Fix some crashes on corrupt type references.

ICSharpCode.Decompiler/IL/InstructionOutputExtensions.cs

@@ -85,7 +85,13 @@ namespace ICSharpCode.Decompiler.IL
 					}
 				case HandleKind.TypeReference: {
 						var tr = metadata.GetTypeReference((TypeReferenceHandle)entity);
-						if (!tr.ResolutionScope.IsNil) {
+						EntityHandle resolutionScope;
+						try {
+							resolutionScope = tr.ResolutionScope;
+						} catch (BadImageFormatException) {
+							resolutionScope = default;
+						}
+						if (!resolutionScope.IsNil) {
 							output.Write("[");
 							var currentTypeRef = tr;
 							while (currentTypeRef.ResolutionScope.Kind == HandleKind.TypeReference) {

ICSharpCode.Decompiler/SRMExtensions.cs

@@ -9,6 +9,7 @@ using System.Reflection.PortableExecutable;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.TypeSystem.Implementation;
 using ICSharpCode.Decompiler.Util;
+using System.Reflection.Metadata.Ecma335;
 
 namespace ICSharpCode.Decompiler
 {
@@ -193,11 +194,27 @@ namespace ICSharpCode.Decompiler
 			if (handle.IsNil)
 				throw new ArgumentNullException(nameof(handle));
 			var tr = reader.GetTypeReference(handle);
-			string name = ReflectionHelper.SplitTypeParameterCountFromReflectionName(reader.GetString(tr.Name), out var typeParameterCount);
+			string name;
+			try {
+				name = reader.GetString(tr.Name);
+			} catch (BadImageFormatException) {
+				name = $"TR{reader.GetToken(handle):x8}";
+			}
+			name = ReflectionHelper.SplitTypeParameterCountFromReflectionName(name, out var typeParameterCount);
 			TypeReferenceHandle declaringTypeHandle;
-			if ((declaringTypeHandle = tr.GetDeclaringType()).IsNil) {
-				string @namespace = tr.Namespace.IsNil ? "" : reader.GetString(tr.Namespace);
-				return new FullTypeName(new TopLevelTypeName(@namespace, name, typeParameterCount));
+			try {
+				declaringTypeHandle = tr.GetDeclaringType();
+			} catch (BadImageFormatException) {
+				declaringTypeHandle = default;
+			}
+			if (declaringTypeHandle.IsNil) {
+				string ns;
+				try {
+					ns = tr.Namespace.IsNil ? "" : reader.GetString(tr.Namespace);
+				} catch (BadImageFormatException) {
+					ns = "";
+				}
+				return new FullTypeName(new TopLevelTypeName(ns, name, typeParameterCount));
 			} else {
 				return declaringTypeHandle.GetFullTypeName(reader).NestedType(name, typeParameterCount);
 			}

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeDefinition.cs

@@ -270,9 +270,17 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 				var context = new GenericContext(TypeParameters);
 				var interfaceImplCollection = td.GetInterfaceImplementations();
 				baseTypes = new List<IType>(1 + interfaceImplCollection.Count);
-				EntityHandle baseType = td.GetBaseTypeOrNil();
-				if (!baseType.IsNil) {
-					baseTypes.Add(module.ResolveType(baseType, context));
+				IType baseType = null;
+				try {
+					EntityHandle baseTypeHandle = td.BaseType;
+					if (!baseTypeHandle.IsNil) {
+						baseType = module.ResolveType(baseTypeHandle, context);
+					}
+				} catch (BadImageFormatException) {
+					baseType = SpecialType.UnknownType;
+				}
+				if (baseType != null) {
+					baseTypes.Add(baseType);
 				} else if (Kind == TypeKind.Interface) {
 					// td.BaseType.IsNil is always true for interfaces,
 					// but the type system expects every interface to derive from System.Object as well.

ILSpy/TextView/DecompilerTextView.cs

@@ -211,10 +211,14 @@ namespace ICSharpCode.ILSpy.TextView
 				return CreateTextBlockForEntity(entity);
 			} else if (segment.Reference is ValueTuple<PEFile, System.Reflection.Metadata.EntityHandle> unresolvedEntity) {
 				var typeSystem = new DecompilerTypeSystem(unresolvedEntity.Item1, unresolvedEntity.Item1.GetAssemblyResolver(), TypeSystemOptions.Default | TypeSystemOptions.Uncached);
-				IEntity resolved = typeSystem.MainModule.ResolveEntity(unresolvedEntity.Item2);
-				if (resolved == null)
+				try {
+					IEntity resolved = typeSystem.MainModule.ResolveEntity(unresolvedEntity.Item2);
+					if (resolved == null)
+						return null;
+					return CreateTextBlockForEntity(resolved);
+				} catch (BadImageFormatException) {
 					return null;
-				return CreateTextBlockForEntity(resolved);
+				}
 			}
 			return null;
 		}