Bug#936090: xfce4-settings: scrollbar disappears, doesn't want to come back

[Mike Kupfer <mkupfer@alum.berkeley.edu>]

Package: xfce4-settings
Version: 4.14.1-1
Severity: normal

Dear Maintainer,

Suppose I go to the Appearance section, which has a nice long list of
styles.

If I drag the scrollbar thumb and then pause while holding the (left)
mouse button down, the scrollbar disappears after about 3 seconds.
That's fine.  But if I release the mouse button and start moving the
mouse around in the list of styles, I'd like for the scrollbar to
reappear.  It doesn't.  Moving the input focus somewhere else and then
back to Appearance doesn't help.  I have to click in the window (not
necessarily in the style list) for the scrollbar to come back.

I've tried several different widget styles, and the problem seems
independent of the style.

I can't reproduce the problem with xfce4-terminal: the scrollbar stays
visible as long as I hold the mouse button.  I can reproduce the
problem with xfce4-settings-editor, but only when run from the
settings manager.  If I start xfce4-settings-editor directly from a
terminal emulator, the scrollbar stays visible as long as I hold the
mouse button.

I do have some GTK settings related to scrollbars.  I don't know if
they're relevant.

In settings.ini:

  gtk-primary-button-warps-slider=0

In gtk-3.0/gtk.css:

  .scrollbar {
  -GtkScrollbar-has-backward-stepper: 1;
  -GtkScrollbar-has-forward-stepper: 1;
  }
  
  scrollbar {
    -GtkScrollbar-has-backward-stepper: true;
    -GtkScrollbar-has-forward-stepper: true;
  }



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

Kernel: Linux 5.2.0-2-amd64 (SMP w/2 CPU cores)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages xfce4-settings depends on:
ii  libatk1.0-0          2.33.3+really2.32.0-4
ii  libc6                2.28-10
ii  libcairo2            1.16.0-4
ii  libcolord2           1.4.3-4
ii  libexo-2-0           0.12.8-1
ii  libfontconfig1       2.13.1-2+b1
ii  libgarcon-1-0        0.6.4-1
ii  libgarcon-common     0.6.4-1
ii  libgdk-pixbuf2.0-0   2.38.1+dfsg-1
ii  libglib2.0-0         2.60.6-2
ii  libgtk-3-0           3.24.10-1
ii  libnotify4           0.7.8-1
ii  libpango-1.0-0       1.42.4-7
ii  libpangocairo-1.0-0  1.42.4-7
ii  libupower-glib3      0.99.10-1
ii  libx11-6             2:1.6.7-1
ii  libxcursor1          1:1.2.0-2
ii  libxfce4ui-2-0       4.14.1-1+b1
ii  libxfce4util7        4.14.0-1
ii  libxfconf-0-3        4.14.1-1
ii  libxi6               2:1.7.9-1
ii  libxklavier16        5.4-4
ii  libxrandr2           2:1.5.1-1
ii  xfconf               4.14.1-1

Versions of packages xfce4-settings recommends:
pn  colord     <none>
ii  x11-utils  7.7+4
pn  xiccd      <none>

xfce4-settings suggests no packages.

-- no debconf information