Bug#805191: libgtk-3-0: scrollbar fails to appear

[Mike Kupfer]

Package: libgtk-3-0
Version: 3.18.4-1
Severity: important

Dear Maintainer,

I upgraded libgtk-3-0 and libgtk-3-common this morning (from 3.18.2-1
to 3.18.4-1).  This changed the scrollbar behavior for the package
list pane in Synaptic.  I verified this in GNOME, Cinnamon, Xfce, and
Mate.

Old behavior: the scrollbar would appear if I moved the mouse into the
package list pane.  (I don't remember if anywhere in the pane worked,
or only if I moved the mouse to the right-hand side of the pane.)

New behavior: I cannot get the scrollbar to appear with just the
mouse.  I can get it to appear by selecting a package and then
pressing the Down key enought times to force the package list to
scroll.  Once the scrollbar appears, I can use it normally, but after
a few seconds of idle time it disappears again.

This is a serious usability regression.

I see the same behavior with Nautilus, though with other apps (GNOME
Terminal, Wireshark), the scrollbar is always visible.

(Can we just get rid of the dynamicall-appearing scrollbar?  It hides
valuable information when it's not visible--there's no visual clue
about how many more packages there are beyond the ones you can see in
the pane.  Also, I recall getting unexpected behavior where I would
click near the bottom of the scrollbar to get a vertical scroll, but a
horizontal scrollbar would appear and I'd get a horizontal scroll
instead.)


-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.2.0-1-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libgtk-3-0 depends on:
ii  libatk-bridge2.0-0                      2.18.1-1
ii  libatk1.0-0                             2.18.0-1
ii  libc6                                   2.19-22
ii  libcairo-gobject2                       1.14.4-1
ii  libcairo2                               1.14.4-1
ii  libcolord2                              1.2.12-1
ii  libcups2                                2.1.0-6
ii  libepoxy0                               1.3.1-1
ii  libfontconfig1                          2.11.0-6.3
ii  libfreetype6                            2.6-2
ii  libgdk-pixbuf2.0-0                      2.32.1-1
ii  libglib2.0-0                            2.46.1-2
ii  libgtk-3-common                         3.18.4-1
ii  libjson-glib-1.0-0                      1.0.4-2
ii  libpango-1.0-0                          1.38.1-1
ii  libpangocairo-1.0-0                     1.38.1-1
ii  libpangoft2-1.0-0                       1.38.1-1
ii  librest-0.7-0                           0.7.93-1
ii  libsoup2.4-1                            2.52.1-1
ii  libwayland-client0                      1.9.0-1
ii  libwayland-cursor0                      1.9.0-1
ii  libwayland-egl1-mesa [libwayland-egl1]  11.0.4-1
ii  libx11-6                                2:1.6.3-1
ii  libxcomposite1                          1:0.4.4-1
ii  libxcursor1                             1:1.1.14-1+b1
ii  libxdamage1                             1:1.1.4-2+b1
ii  libxext6                                2:1.3.3-1
ii  libxfixes3                              1:5.0.1-2+b2
ii  libxi6                                  2:1.7.5-1
ii  libxinerama1                            2:1.1.3-1+b1
ii  libxkbcommon0                           0.5.0-1
ii  libxml2                                 2.9.2+zdfsg1-4
ii  libxrandr2                              2:1.5.0-1
ii  shared-mime-info                        1.5-2

Versions of packages libgtk-3-0 recommends:
ii  libgtk-3-bin  3.18.2-1

Versions of packages libgtk-3-0 suggests:
ii  gvfs             1.26.2-1
ii  librsvg2-common  2.40.11-1

-- no debconf information