Seems to do exactly like you said. If you just use
while true
for an infinite loop the closing of the GUI by the user will not terminate the loop so it will carry on and on and on.
I just tried this to confirm as I have never done it myself.
You can easily create a test program with a single pushbutton in a GUI with a while loop under it. If you try the while true option you'll likely have to resort to Ctrl C to stop it though!
