Impact: mouse movements are incorrect when a display is placed to the left of or above the "primary" display (negative coordinates in use)
How the bug is addressed: revert to having signed ints representing coordinates on screens so that negative coordinates can be properly used
Testcase: see original report
Regression potential: no obvious regression potential
=== Original report ===
Binary package hint: xorg
The mouse is unusable on a second monitor using the nvidia drivers and Xinerama (Installed: 2:1.1-2). Upon moving to the second screen, the mouse cursor movement is erratic (although it does respond vaguely to physical mouse movement).
The problem was introduced with lucid (and continues in beta 2). The mouse works as expected on the second screen in both intrepid and karmic with exact same xorg.conf and nvidia drivers.
The problem appears even with only the minimal settings in xorg.conf to enable dual monitors. The problem appears whether the second monitor is rotated or not rotated. The problem does not occur with nvidia's TwinView implementation.
The mouse and all other aspects of X work fine in lucid *without* Xinerama enabled. Enabling Xinerama causes no problems except this one. The bug is not present in Debian unstable.
The new bug of course forces one to use separate X servers when wishing to rotate only one monitor in a set -- a limitation that was not present in prior releases of Ubuntu or other distributions.
DistroRelease: Ubuntu 10.04
Package: xorg 1:7.5+5ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-20.30-generic 18.104.22.168+drm33.2
Uname: Linux 2.6.32-20-generic x86_64
Date: Wed Apr 14 09:15:52 2010
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta amd64 (20100406)
MachineType: Gigabyte Technology Co., Ltd. EP45-UD3P
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-20-generic root=/dev/mapper/vg0-root ro
PATH=(custom, no user)
Error: command ['xrandr', '--verbose'] failed with exit code 1: Xlib: extension "RANDR" missing on display ":0.1".
RandR extension missing
dmi.bios.vendor: Award Software International, Inc.
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
glxinfo: Error: [Errno 2] No such file or directory