QProcess support for giving subprocess a tty

Currently any process run with QProcess detects it is not running in a terminal. This results in the process buffering it's output so, that it's not flushed even on newline output. Often QProcess is used to run a tool like tar, where it would be very desirable to have it flush after every line, so progress can be shown to user.

There seems to be no way to make QProcess run the subprocess with a terminal. For example in Linux, I think the terminal needs to be set up after fork, but before doing exec for the new process.

To be clear: I don't mean running the process in an actual terminal window, just that the process will detect it's running in terminal, and flush stdout and stderr accordingly.