From 3d500e62f6206ad11308b18976246366aed8c1a5 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sat, 5 Jun 2021 19:54:45 +0200
Subject: [PATCH] avfilter/vf_ciescope: Fix undefined behavior in rgb_to_xy()
 with black

Fixes: floating point division by 0
Fixes: undefined behavior in handling NaN
Fixes: Ticket 8268

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavfilter/vf_ciescope.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavfilter/vf_ciescope.c b/libavfilter/vf_ciescope.c
index b3b906f517..cafdb915ea 100644
--- a/libavfilter/vf_ciescope.c
+++ b/libavfilter/vf_ciescope.c
@@ -849,7 +849,8 @@ rgb_to_xy(double rc,
     *z = m[2][0] * rc + m[2][1] * gc + m[2][2] * bc;
 
     sum = *x + *y + *z;
-
+    if (sum == 0)
+        sum = 1;
     *x = *x / sum;
     *y = *y / sum;
 }