launched QProcess on windows inherits handles, when started detached

Launching a setup.exe (by example) whch updates a Qt app (auto-update), even if the app directly exists upon the setup launch produced locked files the setup was unable to overwrite.
This was due to a strange default behavior of the QProcess startDetached() : 

QProcess process;

process.setProgram("setup.exe");

I had to add this line : 

#ifdef Q_OS_WIN

{{ process.setCreateProcessArgumentsModifier([](QProcess::CreateProcessArguments *args) { args->inheritHandles = false; });}}

#endif

So maybe default behavior is not the correct one on Windows...