Recusive instance in dict causes IronPython crashing.

Please see the following example. In the index of dict d, class test is instanced and then IronPython crashes.

test.py

d = {} 
 
class test: 
    def __hash__(self): 
        d[self] = None 
 
d[test()] = None 

Crash report

......
Interpreter.InterpretedFrame frame) [0x00000] in <252827dbc7924637ba1c8c95b5f54810>:0
at Microsoft.Scripting.Interpreter.Interpreter.Run (Microsoft.Scripting.Interpreter.InterpretedFrame frame) [0x00016] in <252827dbc7924637ba1c8c95b5f54810>:0
at Microsoft.Scripting.Interpreter.LightLambda.Run1[T0,TRet] (T0 arg0) [0x0003e] in <252827dbc7924637ba1c8c95b5f54810>:0
at IronPython.Compiler.RuntimeScriptCode.InvokeTarget (Microsoft.Scripting.Runtime.Scope scope) [0x0006a] in <5cd2739cd27844619789a1aa1ffdb0b0>:0
at IronPython.Compiler.RuntimeScriptCode.Run (Microsoft.Scripting.Runtime.Scope scope) [0x00000] in <5cd2739cd27844619789a1aa1ffdb0b0>:0
at IronPython.Hosting.PythonCommandLine.RunFileWorker (System.String fileName) [0x000e5] in <5cd2739cd27844619789a1aa1ffdb0b0>:0
at IronPython.Hosting.PythonCommandLine.RunFile (System.String fileName) [0x0000f] in <5cd2739cd27844619789a1aa1ffdb0b0>:0
at Microsoft.Scripting.Hosting.Shell.CommandLine.Run () [0x0003a] in <252827dbc7924637ba1c8c95b5f54810>:0
at IronPython.Hosting.PythonCommandLine.Run () [0x000d8] in <5cd2739cd27844619789a1aa1ffdb0b0>:0
at Microsoft.Scripting.Hosting.Shell.CommandLine.Run (Microsoft.Scripting.Hosting.ScriptEngine engine, Microsoft.Scripting.Hosting.Shell.IConsole console, Microsoft.Scripting.Hosting.Shell.ConsoleOptions options) [0x0003c] in <252827dbc7924637ba1c8c95b5f54810>:0
at Microsoft.Scripting.Hosting.Shell.ConsoleHost.RunCommandLine () [0x00053] in <252827dbc7924637ba1c8c95b5f54810>:0
at Microsoft.Scripting.Hosting.Shell.ConsoleHost.ExecuteInternal () [0x00051] in <252827dbc7924637ba1c8c95b5f54810>:0
at PythonConsoleHost.ExecuteInternal () [0x00025] in <9cafe2448f474c41b81ba0c1d71815eb>:0
at Microsoft.Scripting.Hosting.Shell.ConsoleHost.Execute () [0x00032] in <252827dbc7924637ba1c8c95b5f54810>:0
at Microsoft.Scripting.Hosting.Shell.ConsoleHost.Run (System.String[] args) [0x0015b] in <252827dbc7924637ba1c8c95b5f54810>:0
at PythonConsoleHost.Main (System.String[] args) [0x00020] in <9cafe2448f474c41b81ba0c1d71815eb>:0

System

IronPython 3.4.0a1 (3.4.0.0001)
[.NETFramework,Version=v4.6 on Mono 6.12.0.122 (64-bit)] on linux

Run test.py with IronPython 3.4.0a1 on Mono 6.12 to reproduce the crash, starting from PythonCommandLine.RunFile in the reported stack. Trace dictionary key insertion and hash handling in the C# implementation; done means the supplied recursive-instance example no longer crashes.