Ignore bit flag AssemblyFlags.PublicKey for assembly definitions

src/Compilers/CSharp/Test/Emit/Attributes/InternalsVisibleToAndStrongNameTests.cs

@@ -1650,8 +1650,8 @@ internal void Foo()
             }
         }
 
-        [Fact(Skip = "Bug 399")]
-        [WorkItem(399, "GitHub")]
+        [Fact]
+        [WorkItem(399, "https://github.com/dotnet/roslyn/issues/399")]
         public void Bug399()
         {
             // The referenced assembly Signed.dll from the repro steps

src/Compilers/Core/Portable/MetadataReader/PEModule.cs

@@ -474,14 +474,18 @@ internal AssemblyIdentity ReadAssemblyIdentityOrThrow()
                 throw new BadImageFormatException(string.Format(CodeAnalysisResources.InvalidAssemblyName, nameStr));
             }
 
-            string cultureName = (!culture.IsNil) ? reader.GetString(culture) : null;
+            string cultureName = culture.IsNil ? null : reader.GetString(culture);
             if (cultureName != null && !MetadataHelpers.IsValidMetadataIdentifier(cultureName))
             {
                 throw new BadImageFormatException(string.Format(CodeAnalysisResources.InvalidCultureName, cultureName));
             }
 
-            var hasPublicKey = (flags & AssemblyFlags.PublicKey) != 0;
-            var publicKeyOrToken = !publicKey.IsNil ? reader.GetBlobBytes(publicKey).AsImmutableOrNull() : default(ImmutableArray<byte>);
+            ImmutableArray<byte> publicKeyOrToken = reader.GetBlobContent(publicKey);
+            bool hasPublicKey;
+
+            if (isReference)
+            {
+                hasPublicKey = (flags & AssemblyFlags.PublicKey) != 0;
                 if (hasPublicKey)
                 {
                     if (!MetadataHelpers.IsValidPublicKey(publicKeyOrToken))
@@ -489,17 +493,30 @@ internal AssemblyIdentity ReadAssemblyIdentityOrThrow()
                         throw new BadImageFormatException(CodeAnalysisResources.InvalidPublicKey);
                     }
                 }
-            else if (isReference)
+                else
                 {
-                if (!publicKeyOrToken.IsDefaultOrEmpty && publicKeyOrToken.Length != AssemblyIdentity.PublicKeyTokenSize)
+                    if (!publicKeyOrToken.IsEmpty &&
+                        publicKeyOrToken.Length != AssemblyIdentity.PublicKeyTokenSize)
                     {
                         throw new BadImageFormatException(CodeAnalysisResources.InvalidPublicKeyToken);
                     }
                 }
+            }
             else
             {
-                // Assembly definitions do not contain public key tokens, but they may contain public key
-                // data without being marked as strong name signed (e.g. delay-signed assemblies).
+                // Assembly definitions never contain a public key token, they only can have a full key or nothing,
+                // so the flag AssemblyFlags.PublicKey does not make sense for them and is ignored.
+                // See Ecma-335, Partition II Metadata, 22.2 "Assembly : 0x20".
+                // This also corresponds to the behavior of the native C# compiler and sn.exe tool.
+                hasPublicKey = !publicKeyOrToken.IsEmpty;
+                if (hasPublicKey && !MetadataHelpers.IsValidPublicKey(publicKeyOrToken))
+                {
+                    throw new BadImageFormatException(CodeAnalysisResources.InvalidPublicKey);
+                }
+            }
+
+            if (publicKeyOrToken.IsEmpty)
+            {
                 publicKeyOrToken = default(ImmutableArray<byte>);
             }
 

src/ExpressionEvaluator/CSharp/Test/ExpressionCompiler/PseudoVariableTests.cs

@@ -1050,8 +1050,8 @@ static void M()
             context.CompileExpression(
                 // typeof(Exception), typeof(A<B<object>>), typeof(B<A<object>[]>)
                 InspectionContextFactory.Empty.Add("$exception", "System.Exception, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089").
-                    Add("1", "A`1[[B`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], 397300B0-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null]], 397300B0-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=null").
-                    Add("2", "B`1[[A`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]][], 397300B0-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=null]], 397300B0-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null"),
+                    Add("1", "A`1[[B`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], 397300B0-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null]], 397300B0-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=1f8a32457d187bf3").
+                    Add("2", "B`1[[A`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]][], 397300B0-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=1f8a32457d187bf3]], 397300B0-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null"),
                 "(object)$exception ?? (object)$1 ?? $2",
                 DkmEvaluationFlags.TreatAsExpression,
                 DiagnosticFormatter.Instance,

src/ExpressionEvaluator/VisualBasic/Test/ExpressionCompiler/PseudoVariableTests.vb

@@ -859,8 +859,8 @@ End Class"
             ' GetType(Exception), GetType(A(Of B(Of Object))), GetType(B(Of A(Of Object)()))
             context.CompileExpression(
                 InspectionContextFactory.Empty.Add("$exception", "System.Exception, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089").
-                    Add("1", "A`1[[B`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], 397300B1-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null]], 397300B1-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=null").
-                    Add("2", "B`1[[A`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]][], 397300B1-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=null]], 397300B1-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null"),
+                    Add("1", "A`1[[B`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], 397300B1-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null]], 397300B1-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=1f8a32457d187bf3").
+                    Add("2", "B`1[[A`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]][], 397300B1-A, Version=2.1.2.1, Culture=neutral, PublicKeyToken=1f8a32457d187bf3]], 397300B1-B, Version=1.2.2.2, Culture=neutral, PublicKeyToken=null"),
                 "If(If($exception, $1), $2)",
                 DkmEvaluationFlags.TreatAsExpression,
                 DiagnosticFormatter.Instance,