Panning doesn't work on Ubuntu 11.10 because the gnome-setting will reset the screen size

[xuyehua]

Issue: When the user try to set the panning by using the command “xrandr --output CRT1 –panning 1600x1200 ”(the panning size should be larger than the mode size) , we can not move the pointer to the new extra area, that means the user can not set panning.
there are two reasons for the issue:
(1)the CRTC cursor confinement has been enabled in the Ubuntu's patch , and it will limit the cursor position (this panning issue has been resolved on Redhat)
(2)even the above issue has been fixed in Ubuntu , the panning also can not be enabled when we set panning at first,
and the reason is that in the package of gnome-settings-deamon , the code will reset the screen size information if there is no matched primary output . However , in the graphic driver , the pscrnpriv -> primaryoutput will not be initialized at any function area , until the gnome-settings-deamon has done the resize operation.
Here I think there may be two bugs in the gnome-setting-deamon
a. for the function get_required_virtual_size() , it should get the screen size , but it get the mode size actually
b. the judgment about ensure_primary is not very exactly , because the primaryoutput has not been initialized at first

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.