From eebe3ea923415bb799443a0fd8430214f01c462c Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Sat, 21 Apr 2018 13:42:39 +1000
Subject: [PATCH] Corrected undefined behaviour

---
 src/libImaging/Effects.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/libImaging/Effects.c b/src/libImaging/Effects.c
index 26b063a11..6d25f4fff 100644
--- a/src/libImaging/Effects.c
+++ b/src/libImaging/Effects.c
@@ -79,6 +79,7 @@ ImagingEffectNoise(int xsize, int ysize, float sigma)
     Imaging imOut;
     int x, y;
     int nextok;
+    int d;
     double this, next;
 
     imOut = ImagingNewDirty("L", xsize, ysize);
@@ -106,7 +107,8 @@ ImagingEffectNoise(int xsize, int ysize, float sigma)
                 this = factor * v1;
                 next = factor * v2;
             }
-            out[x] = (unsigned char) (128 + sigma * this);
+            d = 128 + sigma * this;
+            out[x] = d<0 ? 0 : (d>UCHAR_MAX ? UCHAR_MAX : d);
         }
     }