> Overall, Firefox is the most consistent. Ctrl+click and 2-finger-click should act the same, but Chrome and Safari are not. Safari should send auxclick for non-primary mouse clicks.

[mohamedmosseb]

Overall, Firefox is the most consistent. Ctrl+click and 2-finger-click should act the same, but Chrome and Safari are not. Safari should send auxclick for non-primary mouse clicks.

Note that after https://bugzilla.mozilla.org/show_bug.cgi?id=1615732 Firefox dispatches mousedown/mouseup with button=0 (instead of button=2) for Ctrl+click, so we would dispatch click event then instead. 2-finger trackpad click behaves the same (mousedown/mouseup with button=2 and auxclick).

I test with https://domeventviewer.com/mouse-event-viewer.html on Firefox Nightly again.

Firefox = Nightly 80.0a1 (2020-06-29)

Click

type	button	buttons	ctrlKey
mousedown	0	1	false
mouseup	0	0	false
click	-	0	false

Ctrl+click

When the contextmenu handler calls preventDefault: type	button	buttons	ctrlKey
mousedown	0	1	true
contextmenu	-	1	true
mouseup	0	0	true
click	-	0	true

2-finger trackpad click

When the contextmenu handler calls preventDefault: type	button	buttons	ctrlKey
mousedown	2	2	false
contextmenu	-	2	false
mouseup	2	0	false
auxclick	-	0	false

Originally posted by @EdgarChen in https://github.com/w3c/uievents/issues/265#issuecomment-652347442