garbage floating scrollbar remains on screen, on top of everything

[Teo]

A scrollbar, probably formerly belonging to some window that has already been closed, has remained on my screen and won't disappear. It is always on top of the active window. It's there, floating.

See attached screenshot: in the screenshot, the background is my desktop (the blue bar is part of the wallpaper); however even if I maximize a window, the scrollbar will remain there.

This is the first time it happens.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity 4.24.0-0ubuntu2.1
ProcVersionSignature: Ubuntu 3.0.0-15.24-generic 3.0.13
Uname: Linux 3.0.0-15-generic i686
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86 Kernel Module 280.13 Wed Jul 27 16:55:43 PDT 2011
 GCC version: gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3)
.tmp.unity.support.test.0:

ApportVersion: 1.23-0ubuntu4
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,vpswitch,mousepoll,compiztoolbox,snap,place,resize,session,regex,grid,wall,move,gnomecompat,imgpng,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CompositorRunning: None
Date: Wed Dec 28 14:50:26 2011
DistUpgraded: Log time: 2011-12-07 19:34:40.350850
DistroCodename: oneiric
DistroVariant: ubuntu
GraphicsCard:
 nVidia Corporation G84 [GeForce 9500M GS] [10de:0405] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:15d2]
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
JockeyStatus:
 xorg:nvidia_173 - NVIDIA accelerated graphics driver (Proprietary, Disabled, Not in use)
 xorg:nvidia_173_updates - NVIDIA accelerated graphics driver (post-release updates) (Proprietary, Disabled, Not in use)
 xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Enabled, In use)
 pkg:sl-modem-daemon - Software modem (Proprietary, Disabled, Not in use)
 xorg:nvidia_current_updates - NVIDIA accelerated graphics driver (post-release updates) (Proprietary, Disabled, Not in use)
MachineType: ASUSTeK Computer Inc. M51Sn
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-15-generic root=UUID=173acbf5-26a0-49e3-8d2b-f1c142582cbf ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: Upgraded to oneiric on 2011-12-07 (20 days ago)
dmi.bios.date: 12/24/2007
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 303
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: M51Sn
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.asset.tag: ATN12345678901234567
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr303:bd12/24/2007:svnASUSTeKComputerInc.:pnM51Sn:pvr1.0:rvnASUSTeKComputerInc.:rnM51Sn:rvr1.0:cvnASUSTeKComputerInc.:ct10:cvr1.0:
dmi.product.name: M51Sn
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK Computer Inc.
version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu6
version.libdrm2: libdrm2 2.4.26-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu3
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg: xserver-xorg 1:7.6+7ubuntu7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu2.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110411+8378443-1

[Teo (teo1978)]

It keeps happening from time to time.
The orphaned scroll bar belongs to gedit. I haven't seen it happen with any other program.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Teo (teo1978)]

I've found out how to systematically REPRODUCE it :

- open any window with enough content to have a vertical scrollbar
- move the mouse cursor over the scroll bar so that the scroller appears
- click and drag it
- keep dragging and move the cursor away from it until the scroller will disappear (this may take moving to the top of the screen or whatever). Still DON'T release the mouse button
- keep dragging and move the mouse cursor into the window again, until the scroller reappears.
- Only NOW release the mouse button

=> now the scroller will stay there forever but it is actually "detached" from the window and does not work.

The orphaned garbage scroller will only disappear when you trigger it to be shown again.

This happens with ANY window, not only gedit.

And now a few steps that demostrate that this bug is of CRITICAL IMPORTANCE as it may eventually lead you to SCREW UP YOUR FILESYSTEM without noticing (it actually happened to me), so it must be given maximum priority:

1. Open Nautilus. Put it in list view and browse to a folder with several subfolders
2. Open Gedit or any other window on top of Nautilus, smaller than Nautilus' window
3. Repeat the steps described above on Gedit so that you leave a garbage orphaned scroller belonging to Gedit
4. Don't move the Gedit window
5. Now move the mouse cursor from _outside_ Gedit window onto the orphaned scroller, on the part that is outside Gedit's window
6. Act as if you think that is actually a real scroller and click on it as if to drag it

=> you will actually be clicking on a folder in Nautilus behind, and dragging it into another folder. Et voila, you have just moved a random folder into another random folder and you may even not have realised it.

More in general, having a GUI element that is usually draggable be left drawn on top of everything and non-functional, means that the user may click on it as if to drag it, but will actually be interacting with whatever is behind it, doing potentially unlimited damage.

[jcard0na (javier-cozybit)]

workaround (disable floating scrollbars):

sudo -i
apt-get remove overlay-scrollbar
echo "export LIBOVERLAY_SCROLLBAR=0" > /etc/X11/Xsession.d/80overlayscrollbars

[Will Cooke (willcooke)]

Sorry folks, but as part of the bug clean up ahead of 16.04 I'm marking this as invalid because it affects an Ubuntu release which is now unsupported. If you can still recreate this bug in a supported release please do open a new bug and we can triage it for consideration in the 16.04 development cycle. As a side note, we are reworking overlay scrollbars in 15.10 and beyond.

[teo1978 (teo8976)]

> As a side note, we are reworking overlay scrollbars in 15.10 and beyond.

OMFG, seriously? Aren't you going to get rid of them? Haven't you realized yet that they are just way worse than traditional scrollbars? I have stopped using them long ago.