From a99f53f682d42071512ad991769a5eb5f7ab0f84 Mon Sep 17 00:00:00 2001
From: Cristy <urban-warrior@imagemagick.org>
Date: Sat, 24 Dec 2016 12:05:52 -0500
Subject: [PATCH] ...

---
 coders/dds.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/coders/dds.c b/coders/dds.c
index b35770c1e..d41706fd8 100644
--- a/coders/dds.c
+++ b/coders/dds.c
@@ -1943,7 +1943,8 @@ static MagickBooleanType ReadDXT1(Image *image,DDSInfo *dds_info,
           SetImageAlpha(image,QuantumRange,exception);
           q=QueueAuthenticPixels(image,x,y,MagickMin(4,image->columns-x),
             MagickMin(4,image->rows-y),exception);
-          SetDXT1Pixels(image,x,y,colors,bits,q);
+          if (q != (Quantum *) NULL)
+            SetDXT1Pixels(image,x,y,colors,bits,q);
         }
 
       if (SyncAuthenticPixels(image,exception) == MagickFalse)
-- 
2.50.1