From 1e95a7df5f2e919ce59c5188d2ad1b30c3ac8595 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Thu, 15 Mar 2012 13:46:56 +1000
Subject: [PATCH] dix: put warning in for scroll increments of 0

If the increment is 0 but this is a scroll axis, it's definitely a bug.
Nonetheless, it has happened, so put a warning in and a return statement
that we avoid the infinite loop and hopefully be able to reproduce later.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Keith Packard <keithp@keithp.com>
---
 dix/getevents.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/dix/getevents.c b/dix/getevents.c
index fa5890eec..7ebddc419 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -1540,6 +1540,10 @@ emulate_scroll_button_events(InternalEvent *events,
     ax = &dev->valuator->axes[axis];
     incr = ax->scroll.increment;
 
+    BUG_WARN_MSG(incr == 0, "for device %s\n", dev->name);
+    if (incr == 0)
+        return 0;
+
     if (type != ButtonPress && type != ButtonRelease)
         flags |= POINTER_EMULATED;