Application menu doesn't honour natural scroll on touchpad when xserver-xorg-input-synaptics is installed

[Andy Jenkins]

Steps to reproduce (Ubuntu 20.04, shell 3.36.1):
1. Enable 'natural scrolling' for the touchpad in mouse and keyboard settings.
2. Open 'Show Applications' -> 'All'
3. Scroll
4. Repeat 2 and 3 with natural scrolling unset

Expectation:
Scrolling 'up' (moving fingers up) moves application icons up with natural scrolling enabled and down with natural scrolling disabled.

Actual outcome:
Scrolling 'up' moves the app icons down (and vice versa) regardless of the natural scrolling setting for the touchpad.

The scrolling behaves as expected when a normal mouse is used (i.e. natural scroll setting of mouse is obeyed).
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
DisplayManager: gdm3
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2017-11-12 (903 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
NonfreeKernelModules: nvidia_modeset nvidia
Package: gnome-shell 3.36.1-5ubuntu1
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
RelatedPackageVersions: mutter-common 3.36.1-3ubuntu3
Tags: focal
Uname: Linux 5.4.0-28-generic x86_64
UpgradeStatus: Upgraded to focal on 2020-04-30 (3 days ago)
UserGroups: adm cdrom dialout dip lpadmin plugdev sambashare sudo wireshark
_MarkForUpload: True

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal:

apport-collect 1876630

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Andy Jenkins (andy-jenks)]

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[Andy Jenkins (andy-jenks)]

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[Andy Jenkins (andy-jenks)]

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[Andy Jenkins (andy-jenks)]

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[Andy Jenkins (andy-jenks)]

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[Andy Jenkins (andy-jenks)]

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[Sebastien Bacher (seb128)]

The issue sounds likely an upstream one, could you report it on https://gitlab.gnome.org/GNOME/gnome-shell/issues ?

[Andy Jenkins (andy-jenks)]

This, along with https://bugs.launchpad.net/gnome-shell/+bug/1876628 occurred because I was using xserver-xorg-input-synaptics, which I gather is no longer supported. Removing this solved the problem.

[Daniel van Vugt (vanvugt)]

IIRC, I implemented synaptics support as a patch to gnome-control-center. The problem is probably there.