Good news: Confirmed I can reproduce the bug. Bad news: The bug only happens in Unity8 and not in Mir demo servers.
What changed: Xmir 2:1.18.4-1ubuntu4 adds accurate vscroll/touchpad support. So instead of synthesising vscroll changes of any magnitude into fake button 4/5 press/releases, it now passes the vscroll float value straight down to the app. This works well in Mir demo servers (with high-resolution touchpads too), but in Unity8 Xmir ends up sending about 7 button 4/5 events per mouse wheel tick. It appears the flaw is in Qt/Unity8 code where a vscroll value of 1.0 (which means one mouse wheel tick) is not correctly maintaining the vscroll value of 1.0 after it passes through Unity8. So the Xmir change is correct, but this is at least the third Unity8/Qt scrolling bug I've seen today. See also bug 1607223 and bug 1605513. ** Also affects: unity8 (Ubuntu) Importance: Undecided Status: New ** Changed in: xorg-server (Ubuntu) Status: New => Invalid ** Also affects: qtmir (Ubuntu) Importance: Undecided Status: New ** Summary changed: - [Xmir Firefox scrolling is too fast (mouse wheel) when run under Unity8 (since Xmir 2:1.18.4-1ubuntu4) + Xmir Firefox scrolling is too fast (mouse wheel) when run under Unity8 (since Xmir 2:1.18.4-1ubuntu4) -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1607240 Title: Xmir Firefox scrolling is too fast (mouse wheel) when run under Unity8 (since Xmir 2:1.18.4-1ubuntu4) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qtmir/+bug/1607240/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp