As has been identified this is a problem with http://cgit.freedesktop.org/xorg/xserver/commit/?id=863d528a9f76d0e8f122aebf19f8564a4c67a938 . Specifically the reordering created seriously messes up the algorithm in certain cases (causing offsets of the starting point for instance). I examined what could possibly cause this error in the first place and the only way I can see this drawing to an off-screen location is if, on the last pass through the X_AXIS while look the !mask if is triggered, pushing the dst out of the range (presumably the last point drawn was the lower right corner, or some other pixel that one to the right of would be a segfault pixel). Then the e>=0 if is triggered which causes another write to this invalid location. However, bits will be 0 at this point because it was just set to 0, therefore the write can be masked by an if (bits) which will always fail in this off-screen condition and therefore save us from a write to an invalid location. There is no similar condition that can cause a write to an invalid location when the axis is Y_AXIS because the only write is at the very top of the loop. Therefore, the sum total of the following patch is to revert 863d528a9f76d0e8f122aebf19f8564a4c67a938 and add the if around the second write in the X_AXIS while statement.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1043575 Title: Xubuntu 12.10 + Xorg server 1.13 = Window decoration missing Status in Xfce4 window manager: Unknown Status in X.Org X server: Confirmed Status in “xorg-server” package in Ubuntu: Incomplete Status in “xorg-server” package in Debian: Fix Released Bug description: I'm running Xubuntu 12.10 with the latest updates and certain themes that use 1pix window border, like Greybird won't show title bar and window borders. This problem exists at least with Nvidia drivers, Vmware and Virtual Box. And it doesn't exist in a fresh Ubuntu 12.04 with xorg server 1.11 using the same drivers. Other people found the same issues, so I think it's a general thing. https://bbs.archlinux.org/viewtopic.php?pid=1152840 To manage notifications about this bug go to: https://bugs.launchpad.net/xfwm4/+bug/1043575/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
