It seems to be related to the /etc/rc.local script after all. I forgot to disable the execution bits the last time; but now I've run chmod -x, the problem really seems to be gone. I've done a fresh install and rebooted over 20 times, but I haven't seen anything weird anymore.
So I think it's safe to say that running something from /etc/rc.local breaks the X session; something that didn't happen in earlier versions. ** Summary changed: - After X update, tty7 is very glitchy + After the latest X update, /etc/rc.local breaks the X session ** Description changed: - Since last night's updates, automatically logging in with LightDM causes - the screen to be blank with only a cursor shown. The desktop does appear - to be rendered on the background, because moving icons and clicking - menus (after guessing where they are) does work. The only way to get - things normal again is by restarting the lightdm service. + Since last night's updates, after booting, the screen is blank with only + a cursor shown. The desktop does appear to be rendered on the + background, because moving icons and clicking menus (after guessing + where they are) does work. The only way to get things normal again is by + restarting the lightdm service, which essentially restarts the X server. It doesn't seem to happen every time, but it does happen a lot. I have - also noticed that when manually logging in, the dmesg output on tty7 - sometimes blends in with the desktop; for instance, a black box with a - blinking cursor is shown, or when plugging in a USB thumb drive, the - output from 'mount' will be displayed, until I move my cursor over that - area. + also noticed that the dmesg output on tty7 sometimes blends in with the + desktop; for instance, a black box with a blinking cursor is shown, or + when plugging in a USB thumb drive, the output from 'mount' will be + displayed, until I move my cursor over that area. I'm running fully up-to-date Xubuntu 12.10 (no proposed packages though) on a laptop with Intel graphics (xserver-xorg-video-intel driver). + + The problem appears to be caused by /etc/rc.local, which contains a line + to set my initial brightness. Removing everything from /etc/rc.local and + disabling the execution bit, seems to fix everything. + + In previous versions, as well as in earlier Ubuntu and Debian installs, + having this script did not cause any trouble. ProblemType: Bug ApportVersion: 2.6.1-0ubuntu2 Architecture: amd64 Date: Wed Oct 10 09:49:02 2012 DistroRelease: Ubuntu 12.10 Package: xserver-xorg 1:7.7+1ubuntu4 PackageArchitecture: amd64 ProcVersionSignature: Ubuntu 3.5.0-17.27-generic 3.5.5 SourcePackage: xorg Tags: quantal Uname: Linux 3.5.0-17-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) ** Tags removed: autologin blank lightdm screen -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1064878 Title: After the latest X update, /etc/rc.local breaks the X session Status in “xorg” package in Ubuntu: Incomplete Bug description: Since last night's updates, after booting, the screen is blank with only a cursor shown. The desktop does appear to be rendered on the background, because moving icons and clicking menus (after guessing where they are) does work. The only way to get things normal again is by restarting the lightdm service, which essentially restarts the X server. It doesn't seem to happen every time, but it does happen a lot. I have also noticed that the dmesg output on tty7 sometimes blends in with the desktop; for instance, a black box with a blinking cursor is shown, or when plugging in a USB thumb drive, the output from 'mount' will be displayed, until I move my cursor over that area. I'm running fully up-to-date Xubuntu 12.10 (no proposed packages though) on a laptop with Intel graphics (xserver-xorg-video-intel driver). The problem appears to be caused by /etc/rc.local, which contains a line to set my initial brightness. Removing everything from /etc/rc.local and disabling the execution bit, seems to fix everything. In previous versions, as well as in earlier Ubuntu and Debian installs, having this script did not cause any trouble. ProblemType: Bug ApportVersion: 2.6.1-0ubuntu2 Architecture: amd64 Date: Wed Oct 10 09:49:02 2012 DistroRelease: Ubuntu 12.10 Package: xserver-xorg 1:7.7+1ubuntu4 PackageArchitecture: amd64 ProcVersionSignature: Ubuntu 3.5.0-17.27-generic 3.5.5 SourcePackage: xorg Tags: quantal Uname: Linux 3.5.0-17-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1064878/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp