LIB: update lodepng

Author: chrisws

src/lib/lodepng.c

@@ -1,7 +1,7 @@
 /*
-LodePNG version 20170917
+LodePNG version 20180114
 
-Copyright (c) 2005-2017 Lode Vandevenne
+Copyright (c) 2005-2018 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
@@ -39,7 +39,7 @@ 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 = "20170917";
+const char* LODEPNG_VERSION_STRING = "20180114";
 
 /*
 This source file is built up in the following large parts. The code sections
@@ -4565,12 +4565,20 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
     const unsigned char* data; /*the data in the chunk*/
 
     /*error: size of the in buffer too small to contain next chunk*/
-    if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(state->error, 30);
+    if((size_t)((chunk - in) + 12) > insize || chunk < in)
+    {
+      if(state->decoder.ignore_end) break; /*other errors may still happen though*/
+      CERROR_BREAK(state->error, 30);
+    }
 
     /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
     chunkLength = lodepng_chunk_length(chunk);
     /*error: chunk length larger than the max PNG chunk size*/
-    if(chunkLength > 2147483647) CERROR_BREAK(state->error, 63);
+    if(chunkLength > 2147483647)
+    {
+      if(state->decoder.ignore_end) break; /*other errors may still happen though*/
+      CERROR_BREAK(state->error, 63);
+    }
 
     if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
     {
@@ -4657,7 +4665,10 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
     else /*it's not an implemented chunk type, so ignore it: skip over the data*/
     {
       /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
-      if(!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69);
+      if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk))
+      {
+        CERROR_BREAK(state->error, 69);
+      }
 
       unknown = 1;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
@@ -4822,6 +4833,8 @@ void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings)
   settings->remember_unknown_chunks = 0;
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
   settings->ignore_crc = 0;
+  settings->ignore_critical = 0;
+  settings->ignore_end = 0;
   lodepng_decompress_settings_init(&settings->zlibsettings);
 }
 

src/lib/lodepng.h

@@ -1,7 +1,7 @@
 /*
-LodePNG version 20170917
+LodePNG version 20180114
 
-Copyright (c) 2005-2017 Lode Vandevenne
+Copyright (c) 2005-2018 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
@@ -255,6 +255,7 @@ const char* lodepng_error_text(unsigned code);
 typedef struct LodePNGDecompressSettings LodePNGDecompressSettings;
 struct LodePNGDecompressSettings
 {
+  /* Check LodePNGDecoderSettings for more ignorable errors */
   unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
 
   /*use custom zlib decoder instead of built in one (default: null)*/
@@ -520,7 +521,10 @@ typedef struct LodePNGDecoderSettings
 {
   LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
 
+  /* Check LodePNGDecompressSettings for more ignorable errors */
   unsigned ignore_crc; /*ignore CRC checksums*/
+  unsigned ignore_critical; /*ignore unknown critical chunks*/
+  unsigned ignore_end; /*ignore issues at end of file if possible (missing IEND chunk, too large chunk, ...)*/
 
   unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
 
@@ -1567,6 +1571,8 @@ For decoding:
 state.decoder.zlibsettings.ignore_adler32: ignore ADLER32 checksums
 state.decoder.zlibsettings.custom_...: use custom inflate function
 state.decoder.ignore_crc: ignore CRC checksums
+state.decoder.ignore_critical: ignore unknown critical chunks
+state.decoder.ignore_end: ignore missing IEND chunk. May fail if this corruption causes other errors
 state.decoder.color_convert: convert internal PNG color to chosen one
 state.decoder.read_text_chunks: whether to read in text metadata chunks
 state.decoder.remember_unknown_chunks: whether to read in unknown chunks
@@ -1608,6 +1614,7 @@ yyyymmdd.
 Some changes aren't backwards compatible. Those are indicated with a (!)
 symbol.
 
+*) 14 jan 2018: allow optionally ignoring a few more recoverable errors
 *) 17 sep 2017: fix memory leak for some encoder input error cases
 *) 27 nov 2016: grey+alpha auto color model detection bugfix
 *) 18 apr 2016: Changed qsort to custom stable sort (for platforms w/o qsort).