From 5b7c4445e83addf3d56d297a645bfd1ed0f25923 Mon Sep 17 00:00:00 2001
From: Aaron Boxer <boxerab@gmail.com>
Date: Wed, 13 Jan 2016 22:42:51 -0500
Subject: [PATCH] do not try to access data pointed to by mqc bp until it
 reaches the start of the mqc buffer

---
 src/lib/openjp2/mqc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/openjp2/mqc.c b/src/lib/openjp2/mqc.c
index 7e0f5637..433ea8e2 100644
--- a/src/lib/openjp2/mqc.c
+++ b/src/lib/openjp2/mqc.c
@@ -203,7 +203,7 @@ static opj_mqc_state_t mqc_states[47 * 2] = {
 */
 
 static void opj_mqc_byteout(opj_mqc_t *mqc) {
-	if (*mqc->bp == 0xff) {
+	if ( (mqc->bp >= mqc->start) & (*mqc->bp == 0xff)) {
 		mqc->bp++;
 		*mqc->bp = (OPJ_BYTE)(mqc->c >> 20);
 		mqc->c &= 0xfffff;