Bug#766707: libgtk-3-0: Mouse scroll wheel not working in GTK 3

[Fredrik Tolf]

Package: libgtk-3-0
Version: 3.14.4-1
Severity: important

Dear Maintainer,

Since sometime in the GTK-3 series (it's been this way for a while,
so I do not remember exactly when it started), mouse wheel scrolling
has not been working.

I believe this is different from #716959, since it only seems to
discuss, mouse-wheel scrolling not working in content areas, while
still working with the pointer placed on the scrollbar itself, and
also seems to be limited to window-managers using the mouse-wheel to
switch workspaces. The problem I'm experiencing is that it isn't
working at all, and I don't have the mouse-wheel bound in the window
manager anyhow.

On the other hand, setting the GDK_CORE_DEVICE_EVENTS environment
variable to "1" makes the problem disappear.

I cannot say that I know the root cause for this problem, unfortunately.
There also seem to be several bugs related to mouse-wheel scrolling in
GTK 3 floating around the web, many of them seemingly confused with
each other, and I just happened to find this work-around without any
sources or reasons cited, at <https://bugs.archlinux.org/task/35348>.
(However, it seems to be confused with a bug in the Oxygen theme,
which I do not use.)

I'm having this problem both with the Testing and Unstable versions of
GTK3.

-- System Information:
Debian Release: jessie/sid
   APT prefers testing
   APT policy: (500, 'testing'), (99, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.14-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libgtk-3-0 depends on:
ii  libatk-bridge2.0-0   2.14.0-2
ii  libatk1.0-0          2.14.0-1
ii  libc6                2.19-11
ii  libcairo-gobject2    1.14.0-2
ii  libcairo2            1.14.0-2
ii  libcolord2           1.2.1-1+b1
ii  libcups2             1.7.5-5
ii  libfontconfig1       2.11.0-6.1
ii  libfreetype6         2.5.2-2
ii  libgdk-pixbuf2.0-0   2.31.1-2+b1
ii  libglib2.0-0         2.42.0-2
ii  libgtk-3-common      3.14.4-1
ii  libjson-glib-1.0-0   1.0.2-1
ii  libpango-1.0-0       1.36.8-2
ii  libpangocairo-1.0-0  1.36.8-2
ii  libpangoft2-1.0-0    1.36.8-2
ii  librest-0.7-0        0.7.92-1
ii  libsoup2.4-1         2.48.0-1
ii  libwayland-client0   1.6.0-2
ii  libwayland-cursor0   1.6.0-2
ii  libx11-6             2:1.6.2-3
ii  libxcomposite1       1:0.4.4-1
ii  libxcursor1          1:1.1.14-1
ii  libxdamage1          1:1.1.4-2
ii  libxext6             2:1.3.3-1
ii  libxfixes3           1:5.0.1-2
ii  libxi6               2:1.7.4-1
ii  libxinerama1         2:1.1.3-1
ii  libxkbcommon0        0.4.3-2
ii  libxml2              2.9.1+dfsg1-4
ii  libxrandr2           2:1.4.2-1
ii  multiarch-support    2.19-11
ii  shared-mime-info     1.3-1

Versions of packages libgtk-3-0 recommends:
ii  hicolor-icon-theme  0.13-1
ii  libgtk-3-bin        3.14.3-1

Versions of packages libgtk-3-0 suggests:
pn  gvfs             <none>
ii  librsvg2-common  2.40.4-1

-- no debconf information