Bug#836426: Graphics rendering (with QXL graphics) doesn't update

[Josh Triplett]

Package: gnome-boxes
Version: 3.20.2-2+b1
Severity: important

("important" because I assume this doesn't happen for everyone.)

Recently, a Windows VM running in gnome-boxes (using the QXL graphics
driver with SPICE) started having an issue with graphical rendering not
updating.  The screen goes black a moment after the login screen shows
up, and never updates.  Resizing the window immediately causes the
contents to show, until the guest notices the change and changes its
video mode to match, at which point the screen goes black again.

This doesn't occur when running via KVM directly, with either the QXL or
vga driver.

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

Kernel: Linux 4.7.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages gnome-boxes depends on:
ii  dconf-gsettings-backend [gsettings-backend]  0.26.0-1
ii  libarchive13                                 3.2.1-2
ii  libatk1.0-0                                  2.21.90-2
ii  libc6                                        2.24-1
ii  libcairo-gobject2                            1.14.6-1+b1
ii  libcairo2                                    1.14.6-1+b1
ii  libgdk-pixbuf2.0-0                           2.34.0-1
ii  libgirepository-1.0-1                        1.49.1-2
ii  libglib2.0-0                                 2.49.6-1
ii  libgovirt2                                   0.3.4-2
ii  libgtk-3-0                                   3.21.5-3
ii  libgtk-vnc-2.0-0                             0.5.3-1.3+b1
ii  libgudev-1.0-0                               230-3
ii  libgvnc-1.0-0                                0.5.3-1.3+b1
ii  libosinfo-1.0-0                              0.3.1-5
ii  libosinfo-bin                                0.3.1-5
ii  libpango-1.0-0                               1.40.2-1
ii  libpangocairo-1.0-0                          1.40.2-1
ii  librest-0.7-0                                0.8.0-1
ii  libsoup2.4-1                                 2.55.90-1
ii  libspice-client-glib-2.0-8                   0.32-1
ii  libspice-client-gtk-3.0-5                    0.32-1
ii  libtracker-sparql-1.0-0                      1.8.0-4+b1
ii  libusb-1.0-0                                 2:1.0.20-1
ii  libuuid1                                     2.28.1-1
ii  libvirt-daemon                               2.1.0-2
ii  libvirt-glib-1.0-0                           0.2.3-2
ii  libvirt0                                     2.1.0-2
ii  libxml2                                      2.9.4+dfsg1-1+b1
ii  mtools                                       4.0.18-2
ii  tracker                                      1.8.0-4+b1

Versions of packages gnome-boxes recommends:
ii  qemu-system-x86  1:2.6+dfsg-3

gnome-boxes suggests no packages.

-- no debconf information