PR comments

src/Compilers/CSharp/Portable/Symbols/Source/SourceAssemblySymbol.cs

@@ -457,6 +457,14 @@ private StrongNameKeys ComputeStrongNameKeys()
                 // the attributes. Right now we'll just fall through to the
                 // "no key available" error.
 
+                if (!string.IsNullOrEmpty(keyFile) && !PathUtilities.IsAbsolute(keyFile))
+                {
+                    // If keyFile has a relative path then there should be a diagnostic
+                    // about it
+                    Debug.Assert(!DeclaringCompilation.Options.Errors.IsEmpty);
+                    return StrongNameKeys.None;
+                }
+
                 // If we're public signing, we don't need a strong name provider
                 return StrongNameKeys.Create(keyFile, MessageProvider.Instance);
             }

src/Compilers/Core/Portable/StrongName/StrongNameKeys.cs

@@ -88,13 +88,14 @@ internal static StrongNameKeys Create(ImmutableArray<byte> publicKey, CommonMess
 
         internal static StrongNameKeys Create(string keyFilePath, CommonMessageProvider messageProvider)
         {
-            if (string.IsNullOrEmpty(keyFilePath) || !PathUtilities.IsAbsolute(keyFilePath))
+            if (string.IsNullOrEmpty(keyFilePath))
             {
                 return None;
             }
 
             try
             {
+                Debug.Assert(PathUtilities.IsAbsolute(keyFilePath));
                 var fileContent = ImmutableArray.Create(PortableShim.File.ReadAllBytes(keyFilePath));
 
                 return CreateHelper(fileContent, keyFilePath);

src/Compilers/VisualBasic/Portable/Symbols/Source/SourceAssemblySymbol.vb

@@ -1593,12 +1593,22 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
                 Return
             End If
 
+            Dim keys As StrongNameKeys
             Dim keyFile As String = _compilation.Options.CryptoKeyFile
 
             ' Public sign requires a keyfile
             If DeclaringCompilation.Options.PublicSign Then
+                If Not String.IsNullOrEmpty(keyFile) AndAlso Not PathUtilities.IsAbsolute(keyFile) Then
+                    ' If keyFile has a relative path then there should be a diagnostic
+                    ' about it
+                    Debug.Assert(Not DeclaringCompilation.Options.Errors.IsEmpty)
+                    keys = StrongNameKeys.None
+                Else
+                    keys = StrongNameKeys.Create(keyFile, MessageProvider.Instance)
+                End If
+
                 ' Public signing doesn't require a strong name provider to be used. 
-                Interlocked.CompareExchange(_lazyStrongNameKeys, StrongNameKeys.Create(keyFile, MessageProvider.Instance), Nothing)
+                Interlocked.CompareExchange(_lazyStrongNameKeys, keys, Nothing)
                 Return
             End If
 
@@ -1621,7 +1631,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
                 End If
             End If
 
-            Dim keys = StrongNameKeys.Create(DeclaringCompilation.Options.StrongNameProvider, keyFile, keyContainer, MessageProvider.Instance)
+            keys = StrongNameKeys.Create(DeclaringCompilation.Options.StrongNameProvider, keyFile, keyContainer, MessageProvider.Instance)
             Interlocked.CompareExchange(_lazyStrongNameKeys, keys, Nothing)
         End Sub