Commit 56f6fb [randr: Avoid re-querying...] breaks Twinview dynamic display configuration

[Aaron Plattner]

This commit causes a regression in dynamic display configuration with the
NVIDIA driver, where trying to switch to a new configuration with
nvidia-settings fails.  The problem is that nvidia-settings adds the new
mode to the list, then queries the mode pool with RRGetScreenInfo.  This
now fails to pick up the new mode and nvidia-settings can't find it,
resulting in a failed mode switch.

https://bugs.launchpad.net/ubuntu/+source/nvidia-settings/+bug/325115
http://www.nvnews.net/vbulletin/showthread.php?t=127359

I'm not sure exactly what the right fix is to avoid reintroducing bug
#19037, but the DIX definitely needs to query the DDX to see if the mode
pool changed.

-- Aaron


commit 56f6fb8c8652c85e522e42557f8969987069076b
Author: Eric Anholt <eric at anholt.net>
Date:   Fri Jan 30 19:06:17 2009 -0800

    randr: Avoid re-querying the configuration on everything but GetScreenResources.
    
    The new path should only re-query on the other requests when we haven't
    gathered the information from the DDX yet (such as with a non-RandR 1.2 DDX).
    
    Bug #19037.
    (cherry picked from commit 317f2b4a9fe4b606975711bc332166a82db5087d)

:100644 100644 b5cebdc... 9c9b7c0... M  randr/randrstr.h
:100644 100644 38314de... 12b9a4a... M  randr/rrinfo.c
:100644 100644 95662c9... da633b2... M  randr/rrscreen.c
:100644 100644 7f9a798... 36135c6... M  randr/rrxinerama.c