From 7525d038cb41979a0e2edfc8273ad8dff7eaa960 Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Sun, 21 Aug 2016 14:10:59 +1000
Subject: [PATCH] Don't attempt to read chunks with bad length Fix #460

Former-commit-id: 86da0c1812ebb3db389d271edf6e8ca81167ba60
Former-commit-id: 93b28d11ed01296011abb4eb6bcb03c89e61ad49
Former-commit-id: 0ecfd461c9a6b5b2fe9aa8632534f8cbd5e0166c
---
 src/ImageProcessorCore/Formats/Png/PngDecoderCore.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/ImageProcessorCore/Formats/Png/PngDecoderCore.cs b/src/ImageProcessorCore/Formats/Png/PngDecoderCore.cs
index a90f9cb8e..f97e085d5 100644
--- a/src/ImageProcessorCore/Formats/Png/PngDecoderCore.cs
+++ b/src/ImageProcessorCore/Formats/Png/PngDecoderCore.cs
@@ -413,6 +413,11 @@ namespace ImageProcessorCore.Formats
                 return null;
             }
 
+            if (chunk.Length <= 0)
+            {
+                return null;
+            }
+
             byte[] typeBuffer = this.ReadChunkType(chunk);
 
             this.ReadChunkData(chunk);