fullscreen applications at non-native resolution work incorrectly

[Alex Walker]

From what I've tested: full-screen applications such as games running at non-native resolution (for example, a 1280x720 fullscreen game running on a 1920x1080 desktop) have weird scaling / stretching issues. Alt+Tabbing and re-selecting the application can sometimes fix it, but there are circumstances in which this won't work, such as a notification appearing.

It's as though Unity tries to redraw the application back to the desktop resolution which is larger than the game resolution, so you only see a stretched top left corner of the game.

Here is a video I recorded showing the issue in OpenRCT2:
https://vid.me/Ocyj

Notice how when I change the volume (causing a notification) the game is stretched to 1920x1080, and goes back to normal once the notification fades. Note on my screen I only see the game part, and the rest is only visible from the screen recording.

Here is another screenshot showing the same happening under wine:
http://i.imgur.com/rOBEEub.png

I'm reporting this under Unity as the above works perfect under GNOME.

Intel HD Graphics 520, Ubuntu 16.04.1 64 Bit.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity 7.4.0+16.04.20160801.2-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-36.55-generic 4.4.16
Uname: Linux 4.4.0-36-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Sat Sep 10 19:51:17 2016
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Sky Lake Integrated Graphics [8086:1916] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Dell Skylake Integrated Graphics [1028:0704]
InstallationDate: Installed on 2016-09-10 (0 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 0c45:670c Microdia
 Bus 001 Device 002: ID 8087:0a2b Intel Corp.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: Dell Inc. XPS 13 9350
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-36-generic.efi.signed root=UUID=cff1bb00-89c0-4fcd-bb56-3ac5fd67c0fd ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/14/2016
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.4.4
dmi.board.name: 07TYC2
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.4.4:bd06/14/2016:svnDellInc.:pnXPS139350:pvr:rvnDellInc.:rn07TYC2:rvrA01:cvnDellInc.:ct9:cvr:
dmi.product.name: XPS 13 9350
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.12.2+16.04.20160801.3-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1ubuntu0.16.04.2
version.libgl1-mesa-dri: libgl1-mesa-dri 11.2.0-1ubuntu2.2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.2.0-1ubuntu2.2
version.xserver-xorg-core: xserver-xorg-core 2:1.18.3-1ubuntu2.3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.7.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160325-1ubuntu1.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Sat Sep 10 19:22:14 2016
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 5193
 vendor SHP
xserver.version: 2:1.18.3-1ubuntu2.3