From 640bad3e7d52d112806095e232a3d989f1a0dd1a Mon Sep 17 00:00:00 2001
From: =?utf8?q?=C3=98yvind=20Kol=C3=A5s?= <pippin@gimp.org>
Date: Thu, 14 Sep 2017 18:32:09 +0200
Subject: [PATCH] babl/base: model-gray, avoid potential NaN

---
 babl/base/model-gray.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/babl/base/model-gray.c b/babl/base/model-gray.c
index d2cf060..6a2764e 100644
--- a/babl/base/model-gray.c
+++ b/babl/base/model-gray.c
@@ -499,7 +499,11 @@ gray_gamma_2_2_premultiplied2rgba (Babl *conversion,
       double alpha = ((double *) src)[1];
       double luminance;
 
-      luma      = luma / alpha;
+      if (alpha > BABL_ALPHA_THRESHOLD)
+        luma      = luma / alpha;
+      else
+        luma      = 0.0;
+
       luminance = babl_trc_to_linear (trc, luma);
 
       ((double *) dst)[0] = luminance;
-- 
2.30.2