[PATCH xserver] xf86ScaleAxis: support for high resolution devices

[Benjamin Tissoires]

High resolution devices was generating integer overflow.
For instance the wacom Cintiq 21UX has an axis value up to
87000. Thus the term (dSx * (Cx - Rxlow)) is greater than
MAX_INT32.

Using 64bits integer avoids such problem.

Signed-off-by: Philippe Ribet <ribet at cena.fr>
Signed-off-by: Benjamin Tissoires <tissoire at cena.fr>
---
 hw/xfree86/common/xf86Xinput.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/xfree86/common/xf86Xinput.c b/hw/xfree86/common/xf86Xinput.c
index 8229227..80bdd19 100644
--- a/hw/xfree86/common/xf86Xinput.c
+++ b/hw/xfree86/common/xf86Xinput.c
@@ -1172,12 +1172,12 @@ xf86ScaleAxis(int	Cx,
               int	Rxlow )
 {
     int X;
-    int dSx = Sxhigh - Sxlow;
-    int dRx = Rxhigh - Rxlow;
+    int64_t dSx = Sxhigh - Sxlow;
+    int64_t dRx = Rxhigh - Rxlow;
 
     dSx = Sxhigh - Sxlow;
     if (dRx) {
-	X = ((dSx * (Cx - Rxlow)) / dRx) + Sxlow;
+	X = (int)(((dSx * (Cx - Rxlow)) / dRx) + Sxlow);
     }
     else {
 	X = 0;
-- 
1.6.6.1