uninitialized null type

[attikov]

in class operator TJsonDataValueHelper.Implicit(const Value: Variant): TJsonDataValueHelper;

{$IFDEF AUTOREFCOUNT} if Result.FData.FObj <> nil then Result.FData.FObj := nil; {$ENDIF AUTOREFCOUNT}

this is (the directive) preventing to initialize the FObj to nil when the passed parameter is "null" causing random AV's (jdtObject with trash addresses)