From b3199a072073ac6292e5bbbd5cce2167f1932ea8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=20=C4=8Cerm=C3=A1k?= <dan.cermak@cgc-instruments.com>
Date: Mon, 3 Sep 2018 21:14:16 +0200
Subject: [PATCH] Fix division by zero in BigTiffImage::printIFD

This fixes #262
---
 src/bigtiffimage.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/bigtiffimage.cpp b/src/bigtiffimage.cpp
index d80e2c51..26165231 100644
--- a/src/bigtiffimage.cpp
+++ b/src/bigtiffimage.cpp
@@ -251,8 +251,12 @@ namespace Exiv2
                             // size * count > std::numeric_limits<uint64_t>::max()
                             // =>
                             // size > std::numeric_limits<uint64_t>::max() / count
-                            if (size > std::numeric_limits<uint64_t>::max() / count)
-                                throw Error(kerInvalidMalloc);             // we got number bigger than 2^64
+                            // (don't perform that check when count == 0 => will cause a division by zero exception)
+                            if (count != 0) {
+                                if (size > std::numeric_limits<uint64_t>::max() / count) {
+                                    throw Error(kerInvalidMalloc);             // we got number bigger than 2^64
+                                }
+                            }
                                                              // more than we can handle
 
                             if (size * count > std::numeric_limits<uint64_t>::max() - pad)