From d1cfeaf0fe2c781eb1d07e8c9af4440259354f08 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 12 Nov 1997 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1997-11-12

---
 port/devmouse.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/port/devmouse.c b/port/devmouse.c
index c2a56a3a3b9154edf85174712e2154213038011c..c2c76a7476c7629f716a684cadd31856601d81c0 100644
--- a/port/devmouse.c
+++ b/port/devmouse.c
@@ -418,11 +418,12 @@ m3mouseputc(void*, int c)
 	short x;
 	int dx, dy, newbuttons;
 
-	/* 
-	 *  check bit 6 for consistency
-	 */
 	if(nb==0){
-		if((c&0x40) == 0){
+		/*
+		 * an extra byte comes for middle button motion.
+		 * only two possible values for the extra byte.
+		 */
+		if(c == 0x00 || c == 0x20){
 			/* an extra byte gets sent for the middle button */
 			middle = (c&0x20) ? 2 : 0;
 			newbuttons = (mouse.buttons & ~2) | middle;