Forwarding this bug from Ubuntu reporter Philip Falkner:
After upgrading to mesa 7.6 (from a mesa git snapshot from mid-August), 1-pixel wide artifacts are displayed on the screen. These disappear on screen repaints.
Starting today, Oct 8, with Kwin compositing active, I get 1-pixel wide artifacts all over the screen. When a window disappears, the very right-most and bottom-most lines of it remain. Sometimes when scrolling in Konqueror, a line from somewhere else in the web page will "stick" at the bottom of the web view (above the status bar). The bouncy cursor icon when launching a new application leaves bits of itself behind.
All of these artifacts disappear when that part of the screen is repainted (e.g. moving a window over the area, activating the present windows effect).
Didn't happen before rebooting this morning, so I'm suspecting mesa 7.6.0.
Date: Thu Oct 8 11:18:00 2009
DistroRelease: Ubuntu 9.10
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 045e:0039 Microsoft Corp. IntelliMouse Optical
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Package: xorg 1:7.4+3ubuntu5
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-12-generic root=UUID=ec6a699c-8cb8-4ef4-b5c9-b83c28ba7696 ro quiet splash
LANG=en_CA.UTF-8ProcVersionSignature: Ubuntu 2.6.31-12.41-generic
Uname: Linux 2.6.31-12-generic i686
XorgConf: Error: [Errno 2] No such file or directory: '/etc/X11/xorg.conf'
XsessionErrors: (<unknown>:1648): Gdk-CRITICAL **: gdk_window_get_origin: assertion `GDK_IS_WINDOW (window)' failed
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: 6.00 PG
glxinfo: Error: [Errno 2] No such file or directory
system: architecture: i686kernel: 2.6.31-12-generic
Created attachment 30168 [details]
Created attachment 30169 [details]
Created attachment 30170 [details]
Created attachment 30171 [details]
Looks like a dup of bug 24248. does reverting:
Created attachment 30185 [details]
Screenshot of KDE's bouncing cursor leaving trails as the mouse moves
Created attachment 30186 [details]
Screenshot of lines remaining after closing the Bookmarks menu
Created attachment 30187 [details]
Screenshot of lines remaining after tooltip from Reload button disappears
Created attachment 30188 [details]
Screenshot of line remaining after scrolling
This one is trickier to see. It's at the bottom of the webview area in Konqueror, only 1 pixel high.
I'll test reverting that patch as soon as I can.
> Looks like a dup of bug 24248. does reverting:
Thanks, I've prepared a package for testing.
Reverting 1d2dca194cebe6e25735b6820f85b8d1231aae63 fixed it here.
*** This bug has been marked as a duplicate of bug 24248 ***