User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0

Steps to reproduce:

Scroll page to bottom by a touchpad, activating kinetic scrolling.
Hit the end of the page. It does not seems to be scrolling anymore.
Press Ctrl+W to close the tab

Actual results:

Kinetic events + CTRL were interpreted as valid Ctrl+Scroll zoom change,
changing zoom to 30% for the website. Tab closed.

Expected results:

Tab closes

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

The version field on this bug says 77 branch, but your User agent string from comment 0 says Firefox 68. Can you confirm which version you're seeing this one? I would have expected the fix from bug 1589046 to take care of this scenario too, but if you still see this problem in a recent Nightly build then I can take a closer look.

Oh actually it makes sense that the fix from the other bug wouldn't impact this one. The OS will still be sending us wheel/pan events and the ctrl modifier gets checked much earlier in the flow than APZ.

This is actually a dupe of bug 1199737.

I don't remember the version. Honestly, I've disabled it by mousewheel.with_control.action years ago because it was so annoying.
I tried to reproduce on firefox 77 on Fedora adon a machine where touchpad does not generate synthetic momentum events. It seems fixed.

By the way, how does https://bugzilla.mozilla.org/show_bug.cgi?id=767197 relate to the two mentioned bug ids?

• firefox 77 shipped by Fedora on Fedora on a machine where touchpad does not generate synthetic momentum events. It seems fixed.

Bug 767197 is the same as bug 1199737 but for linux while 1199737 is for windows. Since you didn't specify what platform/version you were using and the UA string in comment 0 said windows that's what I assumed.