--- /n/sources/plan9/sys/src/9/port/devmouse.c	Thu Jun 13 21:25:32 2013
+++ /sys/src/9/port/devmouse.c	Wed Nov  2 00:00:00 2016
@@ -680,7 +680,7 @@
 int
 m5mouseputc(Queue*, int c)
 {
-	static uchar msg[3];
+	static uchar msg[4];
 	static int nb;
 	static ulong lasttick;
 	ulong m;