From 466acf56a13a1afa88cefbb249b535088d077c20 Mon Sep 17 00:00:00 2001
From: Luis Diaz Mas <piponazo@gmail.com>
Date: Tue, 25 Dec 2018 16:54:26 +0100
Subject: [PATCH] Fix ICC profile in PNG images

(cherry picked from commit 9a38066b8eddf3948696a3362aac29e012ebe690)
---
 src/pngimage.cpp | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/pngimage.cpp b/src/pngimage.cpp
index ed7399a..49c8336 100644
--- a/src/pngimage.cpp
+++ b/src/pngimage.cpp
@@ -468,7 +468,20 @@ namespace Exiv2 {
                 }
                 else if (!memcmp(cheaderBuf.pData_ + 4, "iCCP", 4))
                 {
-                    zlibToDataBuf(cdataBuf.pData_ +12+1,dataOffset-13,iccProfile_); // +1 = 'compressed' flag
+                    // The ICC profile name can vary from 1-79 characters.
+                    uint32_t iccOffset = 0;
+                    while (iccOffset < 80 && iccOffset < dataOffset) {
+
+                        const byte* profileName = cdataBuf.pData_ + iccOffset;
+                        ++iccOffset;
+
+                        if (*profileName == 0x00)
+                            break;
+                    }
+
+                    ++iccOffset; // +1 = 'compressed' flag
+
+                    zlibToDataBuf(cdataBuf.pData_ +iccOffset,dataOffset-iccOffset,iccProfile_);
 #ifdef DEBUG
                     std::cout << "Exiv2::PngImage::readMetadata: Found iCCP chunk length: " << dataOffset  << std::endl;
                     std::cout << "Exiv2::PngImage::readMetadata: iccProfile.size_ : " << iccProfile_.size_ << std::endl;
@@ -627,6 +640,7 @@ namespace Exiv2 {
 
                         // calculate CRC
                         uLong   tmp = crc32(0L, Z_NULL, 0);
+                        tmp         = crc32(tmp, (const Bytef*)type             ,typeLen);
                         tmp         = crc32(tmp, (const Bytef*)header           ,headerLen);
                         tmp         = crc32(tmp, (const Bytef*)compressed.pData_,compressed.size_);
                         byte    crc[4];
-- 
1.8.3.1