For some time when you pressed button 1 on the Mac Book Air 4,2 under Linux/Xorg and moved the finger (classic select something on the screen behaviour), a button 3 (right click) even was emitted.

Current status

As reported on bugzilla, it seems Peter Hutterer merged the relevant fixes into the master tree, which were submitted by Chase Douglas in the patches 9210 until 9219 (9214 and 9215 seem to be the relevant ones)

I haven't tested it so far, but the commits around the merge look good!