Okay, there's indeed an OSC 112 (that is: \e ] 112 \a) in the output.
You could try installing the libvte-2.90-9 package from Utopic (and then restart all gnome-terminal instances), I'm pretty certain this would fix your problem. (I hope it doesn't have dependency problems.)
(I'm not giving this piece of advice on Ubuntu's behalf and it's not my decision if they'll backport the fix to Trusty. I'm keeping an eye on mainstream gnome-terminal/vte, where this bug is most likely alrady fixed.)
Okay, there's indeed an OSC 112 (that is: \e ] 112 \a) in the output.
You could try installing the libvte-2.90-9 package from Utopic (and then restart all gnome-terminal instances), I'm pretty certain this would fix your problem. (I hope it doesn't have dependency problems.)
(I'm not giving this piece of advice on Ubuntu's behalf and it's not my decision if they'll backport the fix to Trusty. I'm keeping an eye on mainstream gnome-terminal/vte, where this bug is most likely alrady fixed.)