From: Andrew de los Reyes <adlr@chromium.org>
Date: Tue, 26 Nov 2013 15:21:15 -0800
Subject: [PATCH] emuWheel.c: Set wheel emulation if REL_WHEEL missing,
 BTN_MIDDLE present.

This is mostly for trackpoint-style devices, but it's just as useful
for mice that lack a middle-button.
---
 src/emuWheel.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/emuWheel.c b/src/emuWheel.c
index dae4031..a094e81 100644
--- a/src/emuWheel.c
+++ b/src/emuWheel.c
@@ -228,6 +228,12 @@ EvdevWheelEmuPreInit(InputInfoPtr pInfo)
     } else
         pEvdev->emulateWheel.enabled = FALSE;
 
+    if (!pEvdev->emulateWheel.enabled &&
+        !EvdevBitIsSet(pEvdev->rel_bitmask, REL_WHEEL) &&
+        EvdevBitIsSet(pEvdev->key_bitmask, BTN_MIDDLE)) {
+        pEvdev->emulateWheel.enabled = TRUE;
+    }
+
     wheelButton = xf86SetIntOption(pInfo->options, "EmulateWheelButton", 4);
 
     if ((wheelButton < 0) || (wheelButton > EVDEV_MAXBUTTONS)) {
-- 
1.8.4.1