'Virtual' screensize lost on upgrade

[Tjarn]

Binary package hint: xorg

Upgrading from 7.10 beta to 7.10 RC -- Toshiba laptop. Upon booting the screen setup was altered. It had been set to 1024x768 physical with a virtual display of 1600x1200. The virtual size was gone.

Examined xorg.conf. It had been altered. Under the Screen section, the entry Virtual 1600 1200 had been altered to Virtual 1024 768. After editing back to 'Virtual 1600 1200' and using the screen sizing tool it worked correctly until rebooting. Upon rebooting it had what looked like a 640x480 screen. Further editing of xorg.conf had no effect.

[Tjarn (tjarn)]

I suspect that this may actually be coming from the tool accessible under the system administration menu with the screen size and resolution tool. It appears that something is testing the screen resolutions, then not honoring the 'Virtual' keyword.

[Bryce Harrington (bryce)]

Please attach your /var/log/Xorg.0.log[.old] files showing the failure. See https://wiki.ubuntu.com/X/Debugging for more info on debugging X problems, and other info you could include to help triage this bug.

[Tjarn (tjarn)]

Bryce -- it appears that this is intimately related to the other bug I reported where X stopped working entirely -- That is bug # 152678. I have attached several xorg.conf files and Xorg.0.log files there. I've been thrashing on this and can give you the scenario a little more explicitly.
(repeat of my info there)
I've determined that my particular problem is caused by this sequence:
1 -- editing xorg.conf to add the line Virtual 1600 1200 (or replacing with one that is correct)
2 -- booting or restarting X -- gdm gives login, login results in a screen not using the virtual size, rather the physical size.
3 -- running the 'Screens and Graphics' tool and selecting the 1600x1200 screen. This comes up and works correctly. However -- the xorg.conf file is destroyed at this point.
Subsequent boots or x restart are mixed. I've had them totally lock, come up in 640x480 mode, and really be a mess or fail to work entirely. With no xorg.conf it does come up in a crippled (no 1600x1200 virtual window) but useable mode. As long as I don't try to use the xorg.conf file that Screens and Graphics poops out I can replace it with a good file and then run. I have determined that if i use xdm instead of gdm it respects my xorg.conf virtual setting. In this scenario, the only downside is needing to use 'shutdown -h now' to stop my session.

This bug is actually two interrelated bugs.

1: gdm does not respect the xorg.conf 'virtual' line.
2: displayconfig-gtk has no clue as to dealing with the 'virtual' line and totally screws up what it writes

At this point deleting the xorg.conf file results in a limited display that can be used for troubleshooting (although not my real work). I am assuming that this is your interest. If so, my congratulations on getting something that works this well.

I've completely deleted gdm from my machine.

I've managed to free up another 3 g partiton and will install the release ISO there and report if I still have problems. In addition will peruse the wiki information.

If there are particular files generated under particular conditions, I'll be delighted to send them to you.

[climatewarrior (gabrieljoel)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!