Crash when compiling dictionary comprehension

[kunom]

The IronPython 2.7.5 runtime crashes when compiling the script below. The culprit seems to be the lambda statement inside of the dictionary comprehension. The repetitive use of 'i' as variable name doesn't seem to matter.

import itertools

def foo(coll):
    def _extract_key(i):
        return i

    print {k:list(g) for k, g in itertools.groupby(coll.iteritems(), lambda i: _extract_key(i))}

foo({1:2, 3:4})

D:\mytemp>ipy -V
IronPython 2.7 2.7.5.0 on .NET 4.0.30319.34209

D:\mytemp>ipy -X:ExceptionDetail dict-comprehension-bug.py
Specified method is not supported.
   at IronPython.Compiler.Ast.ScopeStatement.GetParentClosureTuple()
   at IronPython.Compiler.Ast.ScopeStatement.CreateVariables(ReadOnlyCollectionBuilder`1 locals, List`1 init)
   at IronPython.Compiler.Ast.ComprehensionScope.AddVariables(Expression expression)
   at IronPython.Compiler.Ast.DictionaryComprehension.Reduce()
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileExtensionExpression(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileMethodCallExpression(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockStart(BlockExpression node)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockStart(BlockExpression node)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.Compile(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileExtensionExpression(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.Compile(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileExtensionExpression(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.Compile(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileTryExpression(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockStart(BlockExpression node)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileAsVoid(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockStart(BlockExpression node)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileBlockExpression(Expression expr, Boolean asVoid)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileNoLabelPush(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.Compile(Expression expr)
   at Microsoft.Scripting.Interpreter.LightCompiler.CompileTop(LightLambdaExpression node)
   at Microsoft.Scripting.Ast.LightLambdaExpression.Compile(Int32 compilationThreshold)
   at IronPython.Runtime.FunctionCode.CompileLambda(LightLambdaExpression code, EventHandler`1 handler)
   at IronPython.Runtime.FunctionCode.UpdateDelegate(PythonContext context, Boolean forceCreation)
   at IronPython.Runtime.FunctionCode.LazyCompileFirstTarget(PythonFunction function)
   at IronPython.Compiler.PythonCallTargets.OriginalCallTarget1(PythonFunction function, Object arg0)
   at IronPython.Runtime.FunctionCaller`1.Call1(CallSite site, CodeContext context, Object func, T0 arg0)
   at System.Dynamic.UpdateDelegates.UpdateAndExecute3[T0,T1,T2,TRet](CallSite site, T0 arg0, T1 arg1, T2 arg2)
   at Microsoft.Scripting.Interpreter.FuncCallInstruction`6.Run(InterpretedFrame frame)
   at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
   at Microsoft.Scripting.Interpreter.LightLambda.Run4[T0,T1,T2,T3,TRet](T0 arg0, T1 arg1, T2 arg2, T3 arg3)
   at IronPython.Compiler.Ast.CallExpression.Invoke1Instruction.Run(InterpretedFrame frame)
   at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
   at Microsoft.Scripting.Interpreter.LightLambda.Run1[T0,TRet](T0 arg0)
   at IronPython.Compiler.RuntimeScriptCode.InvokeTarget(Scope scope)
   at IronPython.Compiler.RuntimeScriptCode.Run(Scope scope)
   at IronPython.Hosting.PythonCommandLine.RunFileWorker(String fileName)
   at IronPython.Hosting.PythonCommandLine.RunFile(String fileName)
SystemError: Specified method is not supported.

[kunom]

This issue also applies to set comprehensions, but not to list comprehensions, since list comprehensions do not have their private scope.

In fact, the ComprehensionScope class should overload ScopeStatement.GetParentClosureTuple().