L.Browser.touch is incorrectly being set when on desktop (Chrome)

[jcarenza]

It appears that recent updates to Chrome (on Mac, at least) have changed their implementation of window.PointerEvent. This causes the current version of Leaflet (1.0.2) to misdiagnose the browser as a touch device and adds the leaflet-touch class.

This line seems to be the culprit:

pointer = window.PointerEvent || msPointer

...it can be found here: https://github.com/Leaflet/Leaflet/blob/v1.0.2/src/core/Browser.js#L33

The problem is that window.PointerEvent is a function, which will always return 'truthy'.

How to reproduce

• Browser: Mac OSX El Capitan (10.11.6), Chrome Version 55.0.2883.95 (64-bit)
• Go to www.leafletjs.com and look at the demo example...the Zoom In/Out buttons are enlarged, due to the leaflet-touch class being applied to the leaflet map container.

[rigoneri]

I can reproduce this as well...

[IvanSanchez]

Duplicate of #3944. There is no way to know if the browser is running on a computer with a touchscreen or not, it's only possible to know if the browser supports touch/pointer events or not. See also http://www.stucox.com/blog/you-cant-detect-a-touchscreen/

[rigoneri]

So, what's the point of detecting touch if it's not going to accurately detect touch? Shouldn't that whole logic be removed from leaflet then?