[PATCH v2] dix: don't BUG_WARN for button events from button-only device

[Daniel Kurtz]

Events from button-only devices still need coordinates, and they get them
from scale_to_desktop().  Therefore, a dev without valuators is not a bug.
However, a dev with valuators, but less than two of them still is a bug.

This was noticed when unplugging a "Creative Technology SB Arena Headset",
which has some BTNs and some KEYs, but no REL or ABS valuators.
It emits [BTN_3] = 0 on unplug, which would trigger the BUG_WARN.

Signed-off-by: Daniel Kurtz <djkurtz at chromium.org>
---
 dix/getevents.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/dix/getevents.c b/dix/getevents.c
index 151d82a..06390cd 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -838,7 +838,7 @@ scale_to_desktop(DeviceIntPtr dev, ValuatorMask *mask,
     ScreenPtr scr = miPointerGetScreen(dev);
     double x, y;
 
-    BUG_WARN(!dev->valuator || dev->valuator->numAxes < 2);
+    BUG_WARN(dev->valuator && dev->valuator->numAxes < 2);
     if (!dev->valuator || dev->valuator->numAxes < 2)
     {
         /* if we have no axes, last.valuators must be in screen coords
-- 
1.7.7.3