[Hardy][patch]xorg.conf should include a big enough virtual screen

[sibidiba]

Binary package hint: xserver-xorg-core

Would it be possible to change xorg.conf's default screen section from

Section "Screen"
        Identifier "Default Screen"
        Monitor "Configured Monitor"
EndSection

to

Section "Screen"
        Identifier "Default Screen"
        Monitor "Configured Monitor"
        DefaultDepth 24
        SubSection "Display"
                Depth 24
                Virtual 2048 2048
        EndSubSection
EndSection

?

This would make it possible for many people with multiple monitors (which is common nowadays) to stretch their desktop across them, without manually editing xorg.conf.
If this is not set, then the video driver usually does not allocates enough (fb?) memory to fit both screens into it.
All intel chips are well-known affected, ATI bug #199337 .
As a result stretching the desktop fails without a hint where to correct the problem.
Xrandr simply does not displays resolutions that would not fit into the maximal resolution, making people believe, that Linux/Ubuntu/the video card does not support the desired one. Also gnome-display-properties just does not works in this case.

With the virtual screen size explicitly given, xrandr indicates the availability of bigger resolutions and gnome-display-properties works:
$ xrandr
Screen 0: minimum 320 x 200, current 1280 x 800, maximum 2048 x 2048

I guess this patch does not affect users who do not use a second display, except from a little higher memory consumption.
Above the square of 2048 DRI breaks on intel chips.

[Bryce Harrington (bryce)]

Unfortunately, specifying Virtual across the board like this causes breakage on some drivers. We do need a way to make it easier to set Virtual sizes, but that's covered by a different bug already.