Sometimes when doing a "sloppy" hard click on the trackpad, the pointer will move enough so that the intended target is not clicked. (A sloppy click being where your finger rolls down as it's clicking).
This was greatly improved in the 0.18 release, but there are additional improvements that can be made.
See https://bugzilla.redhat.com/show_bug.cgi?id=1230441 for related information.
See the attached image for a better description of what is going on. In the image, it was intended that the dots line up horizontally. For the dots that don't line up, that's because the pointer moved before the click was registered.
Created attachment 116699 [details]
attempted sloppy hard clicks on paint app
Created attachment 116700 [details]
single hard click recording
Created attachment 116701 [details]
multiple hard clicks recording
for the archives, we need to track pressure changes to predict this (not possible on all touchpads)
No-one is currently working on this, anyone to stumble across this bug please feel free to take it.
Small update: I was testing this on an apple laptop recently and afaict they have a bottom button area (hidden of course since they use clickfinger to actually click) where this motion gets discarded. This could be a solution for libinput, where clickfinger is enabled, the lower area of the touchpad could be less sensitive to movements for a short timeout after finger down.
*** Bug 94861 has been marked as a duplicate of this bug. ***
can you try this with libinput master please? we now have touch pressure detection so we should detect a touch a bit later than before. This may help with this bug (but it's not a guarantee)
needinfo for 6+ weeks, and I think it may have improved with 1.8 anyway. let's re-open this if necessary