Description of problem:
trackpad has left and right click capabilities. Right click does not work anymore after upgrade from F27 to F28.
This is Gnome on Xorg here.
My model is Lenovo T440s but I assume this may apply to many Lenovo models.
Version-Release number of selected component (if applicable):
Not sure I selected the right component (if so, then libinput-1.10.4-2.fc28)
Steps to Reproduce:
3. Try right-click anywhere
Context menus and so on
FYI: Update to v 1.10.5-3.fc28 from `updates-testing`  does not solve the problem.
I'm assuming it's this one:
Of course, it was this one. Sorry for not doing the research on my end. And thanks devs for this feature!
I wasted some time on this too. I thought that my cheap netbook had a hardware failure. Booting a live Fedora 27 stick showed me that the hardware remained fine.
Playing with libinput-debug-events showed that libinput was still seeing right-clicks.
I'd say that this Gnome default change is a bug in the release notes for Fedora 28. Behaviour that changes in a surprising way should come with a warning and an explanation.
The fact that you need the tweak tool add-on to provide a graphical way configure the behaviour is an unfortunate feature of Gnome.
(I do seem to have gained a way to middle-click, and that is great!)