I have built a Qt app which upon receipt of the HUP signal shuts down nicely (setup like this how to get signals into Qt). This works great under Red Had 6, but when I run this app under Ubuntu 14 my app receives the HUP signal immediately (after forking to run in the background) and then shuts down - even though I didn't send a HUP. Furthermore, this ONLY happens when my app forks and runs in the background - if I run my app in the foreground it does not receive the hup unexpectedly.
Is there some other reason that might cause it to receive a HUP signal when daemonized? (And why under one distro but not the other)