NotSupportedException on marshalling class to variant without type lib

Author: elinor-fung

src/coreclr/dlls/mscorrc/mscorrc.rc

@@ -524,6 +524,7 @@ BEGIN
     IDS_EE_INVALIDCOMDEFITF                 "Type '%1' has an invalid default COM interface: '%2'."
     IDS_EE_COMDEFITFNOTSUPPORTED            "Type '%1' does not support the specified default COM interface: '%2'"
 
+    IDS_EE_CLASS_TO_VARIANT_TLB_NOT_REG     "Type '%1' cannot be marshalled to a Variant. Type library is not registered."
     IDS_EE_CANNOT_MAP_TO_MANAGED_VC         "The specified record cannot be mapped to a managed value class."
 
     IDS_EE_SAFEHANDLECLOSED                 "Safe handle has been closed"

src/coreclr/dlls/mscorrc/resource.h

@@ -270,6 +270,7 @@
 #define IDS_EE_INVALIDCOMDEFITF                 0x1a32
 #define IDS_EE_COMDEFITFNOTSUPPORTED            0x1a33
 
+#define IDS_EE_CLASS_TO_VARIANT_TLB_NOT_REG     0x1a35
 #define IDS_EE_CANNOT_MAP_TO_MANAGED_VC         0x1a36
 
 #define IDS_EE_MARSHAL_UNMAPPABLE_CHAR          0x1a37

src/coreclr/vm/olevariant.cpp

@@ -4710,7 +4710,21 @@ void OleVariant::ConvertValueClassToVariant(OBJECTREF *pBoxedValueClass, VARIANT
 
     // Retrieve the ITypeInfo for the value class.
     MethodTable *pValueClassMT = (*pBoxedValueClass)->GetMethodTable();
-    IfFailThrow(GetITypeInfoForEEClass(pValueClassMT, &pTypeInfo, true /* bClassInfo */));
+    hr = GetITypeInfoForEEClass(pValueClassMT, &pTypeInfo, true /* bClassInfo */);
+    if (FAILED(hr))
+    {
+        if (hr == TLBX_E_LIBNOTREGISTERED)
+        {
+            // Indicate that conversion of the class to variant without a registered type lib is not supported
+            StackSString className;
+            pValueClassMT->_GetFullyQualifiedNameForClass(className);
+            COMPlusThrow(kNotSupportedException, IDS_EE_CLASS_TO_VARIANT_TLB_NOT_REG, className.GetUnicode());
+        }
+        else
+        {
+            COMPlusThrowHR(hr);
+        }
+    }
 
     // Convert the ITypeInfo to an IRecordInfo.
     hr = GetRecordInfoFromTypeInfo(pTypeInfo, &V_RECORDINFO(pRecHolder));