dialog --pause not timing out on serial console (dialog 1.2)

[Stefan Puiu]

Hi,

We have a hardware x86-64 board that is headless, the only way to
connect to it is either a serial console or ssh. We have a "reset to
factory" procedure that involves booting a certain grub configuration
that puts a dialog on the serial console, making it possible to cancel
the operation until a timer expires; then, it proceeds with the rest
of the operation. We are basically calling dialog like this:

dialog --ok-label "Reset to factory defaults" --cancel-label Cancel
--title "Reset to factory defaults" --pause "\n\n Resetting to factory
defaults. \n\n\n You can cancel the operation in 30 seconds." 20 60 30

The system boots Linux (a really old Fedora 20, which we I don't think
we can change at this point), then autologins as root, runs the dialog
and then proceeds to perform the restore. What we're seeing is that
sometimes the timer fails to... well, time out. If I ssh to the box, I
see dialog is still running. If I connect to the board using the
serial console, the timer starts, expires and then proceeds to perform
the other operations. I've also added some logging to the script and
noticed the dialog startup doesn't seem to be delayed. It seems that
sometimes (not always) I have to connect to the serial console for the
dialog timer to start. Is this a known issue in older versions of
dialog or ncurses? I'm trying to gauge if a newer version of either
might fix things.

We have dialog 1.2 (release 4.20130902.fc20) and ncurses 5.9 (release
12.20130511.fc20), I know, ancient stuff.

Thanks,
Stefan.