Bug#985135: Backport touch screen fix from testing

[Thomas Mühlbacher]

Package: libgtk-3-0
Version: 3.24.5-1

Please backport this fix, that's already in bullseye, to Debian 10:

https://salsa.debian.org/gnome-team/gtk3/-/commit/faa748d4c9b03ff7c47f15f3504e42d9af0dd4da

It would be very helpful to have this work, since beyond the issues
described in the original bug report it also breaks touch input on
certain other widgets in other applications using GTK 2. For example
when using the LXDE desktop together with NetworkManager's `nm-applet`.
After interacting with the applet in the systray, the LXDE start menu
and other widgets, like combo boxes and buttons, become completely
unresponsive to touch input.

I bisected the issue, since I realized that it doesn't happen on
testing/unstable and was eventually able to tell it works correctly
since `debian/3.24.22-1`. After looking through the commits in this
release, I tried the current version in buster with just the two
commits from the MR cherry picked and it solves the issue.

I even tried GNOME on Xorg with Nautilus as discussed in the upstream
issue:

https://gitlab.gnome.org/GNOME/gtk/-/issues/945

However, I could not find the behavior to be in any way worse than it is
currently, so I don't think it introduces any kind of regression,
actually.

-- 

Cheers,
Thomas Mühlbacher