[IronPython] Fail to execute "import System" on Silverlight embedded interpreter

[Kay Schluehr]

Hi IronPython list,

I worked along Michael Foords introductory article about embedding 
IronPython in Silverlight together with his 
"EmbeddingIronPythonSilverlight" project documented here:

http://www.voidspace.org.uk/ironpython/silverlight/embedding_ironpython.shtml

I added the following two lines to the source code

  source = pe.CreateScriptSourceFromString("import System", 
SourceCodeKind.Statements);
  source.Execute(scope);

This worked all well with the given built and the shipped assemblies.

Yesterday I downloaded the DLR dlr-34133, built it and replaced the 
assemblies of the "EmbeddingIronPython..." project with the latest 
SilverlightDebug ones. Running the code
again I get following import error:

System.NullReferenceException wurde nicht von Benutzercode behandelt.
  Message="Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt."
  StackTrace:
       bei Microsoft.Scripting.Silverlight.DynamicApplication.get_BaseUri()
       bei 
Microsoft.Scripting.Silverlight.DynamicApplication.MakeUri(Uri baseUri, 
Uri relativeUri)
       bei 
Microsoft.Scripting.Silverlight.HttpVirtualFilesystem.GetFileInternal(Object 
baseUri, Uri relativeUri)
       bei 
Microsoft.Scripting.Silverlight.BrowserVirtualFilesystem.GetFileInternal(Object 
storageUnit, String relativePath)
       bei 
Microsoft.Scripting.Silverlight.BrowserVirtualFilesystem.GetFile(Object 
storageUnit, String relativePath)
       bei 
Microsoft.Scripting.Silverlight.BrowserVirtualFilesystem.GetFile(String 
relativePath)
       bei Microsoft.Scripting.Silverlight.BrowserPAL.FileExists(String 
path)
       bei IronPython.Runtime.Importer.LoadModuleFromSource(CodeContext 
context, String name, String path)
       bei IronPython.Runtime.Importer.LoadPackageFromSource(CodeContext 
context, String name, String path)
       bei IronPython.Runtime.Importer.LoadFromDisk(CodeContext context, 
String name, String fullName, String str)
       bei IronPython.Runtime.Importer.ImportFromPathHook(CodeContext 
context, String name, String fullName, List path, Func`5 defaultLoader)
       bei IronPython.Runtime.Importer.ImportFromPath(CodeContext 
context, String name, String fullName, List path)
       bei IronPython.Runtime.Importer.ImportTopAbsolute(CodeContext 
context, String name)
       bei IronPython.Runtime.Importer.ImportModule(CodeContext context, 
Object globals, String modName, Boolean bottom, Int32 level)
       bei IronPython.Modules.Builtin.__import__(CodeContext context, 
String name, Object globals, Object locals, Object fromlist, Int32 level)
  InnerException:


Apparently, pre-loading assemblies in the loop

    foreach (string name in new string[] { "mscorlib", "System", 
"System.Windows", "System.Windows.Browser", "System.Net" })
    {
        
runtime.LoadAssembly(runtime.Host.PlatformAdaptationLayer.LoadAssembly(name));
    }

had no effect and IronPython attempts to load the 'System' module from 
the disk as a Python module. The standard import
routine "import clr; clr.AddReference("System"); import System" causes 
the same problem. I'm puzzled.

Regards, Kay