Supports(..) liefert Referenz welche AV auslöst

[Sir Rufo]

Nur so fürs Protokoll, versuche es mal so

Delphi-Quellcode:

program dp_183554;

{$APPTYPE CONSOLE}
{$R *.res}

uses
  System.SysUtils;

type
  IMyInterface = interface
    ['{88DDD9A5-F4BC-47B9-9240-31B1C986F230}']
    procedure doSomething( );
  end;

  TMyClass = class( TInterfacedObject, IMyInterface )
  public
    constructor Create( );
    procedure doSomething( );
  end;

procedure justSupportsThings( );
var
  myObject: TObject;
  myIntf: IMyInterface;
  castSuccessful: Boolean;
begin
  myObject := TMyClass.Create( );
  castSuccessful := Supports( myObject, IMyInterface, myIntf );
  if castSuccessful
  then
    myIntf.doSomething( );
end;

constructor TMyClass.Create( );
begin
  inherited;
  // Schwachfug
  //  _AddRef(); // Damit mich das Supports(..) nicht abräumt
end;

procedure TMyClass.doSomething;
begin
  // nop
end;

begin
  try
    justSupportsThings( );
  except
    on E: Exception do
      Writeln( E.ClassName, ': ', E.Message );
  end;
  readln;

end.