[PATCH] Xi: check button mapping value _before_ assigning it

[Peter Hutterer]

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 Xi/exevents.c |   12 ++++--------
 1 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/Xi/exevents.c b/Xi/exevents.c
index 6297d6c..0a40cfd 100644
--- a/Xi/exevents.c
+++ b/Xi/exevents.c
@@ -1742,11 +1742,9 @@ ProcessDeviceEvent(InternalEvent *ev, DeviceIntPtr device)
                 deactivateDeviceGrab = TRUE;
             break;
         case ET_ButtonPress:
-            event->detail.button = b->map[key];
-            if (!event->detail.button) { /* there's no button 0 */
-                event->detail.button = key;
+            if (b->map[key] == 0) /* there's no button 0 */
                 return;
-            }
+            event->detail.button = b->map[key];
             if (!grab && CheckDeviceGrabs(device, event, 0))
             {
                 /* if a passive grab was activated, the event has been sent
@@ -1755,11 +1753,9 @@ ProcessDeviceEvent(InternalEvent *ev, DeviceIntPtr device)
             }
             break;
         case ET_ButtonRelease:
-            event->detail.button = b->map[key];
-            if (!event->detail.button) { /* there's no button 0 */
-                event->detail.button = key;
+            if (b->map[key] == 0) /* there's no button 0 */
                 return;
-            }
+            event->detail.button = b->map[key];
             if (grab && !b->buttonsDown &&
                 device->deviceGrab.fromPassiveGrab &&
                 (device->deviceGrab.grab->type == ButtonPress ||
-- 
1.7.7.1