various fixes

3 files changed, 55 insertions, 11 deletions

diff --git a/lodepng.cpp b/lodepng.cpp
index 8b6076d..8665292 100644
--- a/lodepng.cpp
+++ b/lodepng.cpp
@@ -1,7 +1,7 @@
 /*
-LodePNG version 20151208
+LodePNG version 20160118
 
-Copyright (c) 2005-2015 Lode Vandevenne
+Copyright (c) 2005-2016 Lode Vandevenne
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -42,7 +42,7 @@ Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for
 #pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
 #endif /*_MSC_VER */
 
-const char* LODEPNG_VERSION_STRING = "20151208";
+const char* LODEPNG_VERSION_STRING = "20160118";
 
 /*
 This source file is built up in the following large parts. The code sections
@@ -2684,12 +2684,18 @@ unsigned lodepng_can_have_alpha(const LodePNGColorMode* info)
 
 size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color)
 {
-  return (w * h * lodepng_get_bpp(color) + 7) / 8;
+  /*will not overflow for any color type if roughly w * h < 268435455*/
+  int bpp = lodepng_get_bpp(color);
+  size_t n = w * h;
+  return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8;
 }
 
 size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
 {
-  return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8;
+  /*will not overflow for any color type if roughly w * h < 268435455*/
+  int bpp = lodepng_get_bpp_lct(colortype, bitdepth);
+  size_t n = w * h;
+  return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8;
 }
 
 
@@ -2698,7 +2704,10 @@ size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colorty
 /*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer*/
 static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color)
 {
-  return h * ((w * lodepng_get_bpp(color) + 7) / 8);
+  /*will not overflow for any color type if roughly w * h < 268435455*/
+  int bpp = lodepng_get_bpp(color);
+  size_t line = ((w / 8) * bpp) + ((w & 7) * bpp + 7) / 8;
+  return h * line;
 }
 #endif /*LODEPNG_COMPILE_DECODER*/
 #endif /*LODEPNG_COMPILE_PNG*/
@@ -3855,7 +3864,11 @@ unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
   {
     CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/
   }
-  if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
+  if(lodepng_chunk_length(in + 8) != 13)
+  {
+    CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/
+  }
+  if(!lodepng_chunk_type_equals(in + 8, "IHDR"))
   {
     CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/
   }
@@ -5923,6 +5936,7 @@ const char* lodepng_error_text(unsigned code)
     case 91: return "invalid decompressed idat size";
     case 92: return "too many pixels, not supported";
     case 93: return "zero width or height is invalid";
+    case 94: return "header chunk must have a size of 13 bytes";
   }
   return "unknown error code";
 }
diff --git a/lodepng.h b/lodepng.h
index 8b8e2d4..2cda86f 100644
--- a/lodepng.h
+++ b/lodepng.h
@@ -1,7 +1,7 @@
 /*
-LodePNG version 20151208
+LodePNG version 20160118
 
-Copyright (c) 2005-2015 Lode Vandevenne
+Copyright (c) 2005-2016 Lode Vandevenne
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -1709,5 +1709,5 @@ Domain: gmail dot com.
 Account: lode dot vandevenne.
 
 
-Copyright (c) 2005-2015 Lode Vandevenne
+Copyright (c) 2005-2016 Lode Vandevenne
 */
diff --git a/pngdetail.cpp b/pngdetail.cpp
index d62b6dd..0f2b602 100644
--- a/pngdetail.cpp
+++ b/pngdetail.cpp
@@ -48,6 +48,7 @@ everything except huge output:
 #include "lodepng_util.h"
 #include <iostream>
 #include <iomanip>
+#include <map>
 #include <sstream>
 #include <algorithm>
 
@@ -169,7 +170,8 @@ void displayChunkNames(const std::vector<unsigned char>& buffer, const Options&
 {
   std::vector<std::string> names;
   std::vector<size_t> sizes;
-  lodepng::getChunkInfo(names, sizes, buffer);
+  unsigned error = lodepng::getChunkInfo(names, sizes, buffer);
+  if(error) std::cout << "Error while identifying chunks. Listing identified chunks anyway." << std::endl;
 
   if(options.show_chunks2)
   {
@@ -197,6 +199,17 @@ void displayChunkNames(const std::vector<unsigned char>& buffer, const Options&
     }
     std::cout << std::endl;
   }
+
+  std::map<std::string, bool> typedict;
+  for(size_t i = 0; i < names.size(); i++) {
+    typedict[names[i]] = true;
+  }
+
+  if(!error) {
+    if(!typedict["IHDR"]) std::cout << "Error: no IHDR chunk" << std::endl;
+    if(!typedict["IDAT"]) std::cout << "Error: no IDAT chunk" << std::endl;
+    if(!typedict["IEND"]) std::cout << "Error: no IEND chunk" << std::endl;
+  }
 }
 
 void RGBtoHSL(unsigned char r, unsigned char g, unsigned char b, unsigned char* h, unsigned char* s, unsigned char* l) {
@@ -784,6 +797,23 @@ unsigned showFileInfo(const std::string& filename, const Options& options)
   state.info_raw.bitdepth = 16;
   error = lodepng::decode(image, w, h, state, buffer);
 
+  // In case of checksum errors, disable checksums
+  while (error == 57 || error == 58) {
+    if(error == 57)
+    {
+      std::cout << "Error: invalid CRC checksum" << std::endl;
+      state.decoder.ignore_crc = 1;
+      error = lodepng::decode(image, w, h, state, buffer);
+    }
+
+    if(error == 58)
+    {
+      std::cout << "Error: invalid Adler32 checksum" << std::endl;
+      state.decoder.zlibsettings.ignore_adler32 = 1;
+      error = lodepng::decode(image, w, h, state, buffer);
+    }
+  }
+
   if(error)
   {
     std::cout << "Decoder error " << error << ": " << lodepng_error_text(error) << std::endl;