fix a few possible empty vector accesses (C++11 not yet used for now), and cleanup a few other unneeded [0]'s

3 files changed, 18 insertions, 18 deletions

diff --git a/lodepng.cpp b/lodepng.cpp
index 33f3ea5..1f89677 100644
--- a/lodepng.cpp
+++ b/lodepng.cpp
@@ -1,5 +1,5 @@
 /*
-LodePNG version 20220618
+LodePNG version 20220717
 
 Copyright (c) 2005-2022 Lode Vandevenne
 
@@ -44,7 +44,7 @@ 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 = "20220618";
+const char* LODEPNG_VERSION_STRING = "20220717";
 
 /*
 This source file is divided into the following large parts. The code sections
@@ -2461,7 +2461,7 @@ static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream,
 /* ////////////////////////////////////////////////////////////////////////// */
 
 unsigned lodepng_chunk_length(const unsigned char* chunk) {
-  return lodepng_read32bitInt(&chunk[0]);
+  return lodepng_read32bitInt(chunk);
 }
 
 void lodepng_chunk_type(char type[5], const unsigned char* chunk) {
@@ -6488,7 +6488,7 @@ unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, si
   size_t buffersize = 0;
   unsigned error = zlib_decompress(&buffer, &buffersize, 0, in, insize, &settings);
   if(buffer) {
-    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    out.insert(out.end(), buffer, &buffer[buffersize]);
     lodepng_free(buffer);
   }
   return error;
@@ -6507,7 +6507,7 @@ unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size
   size_t buffersize = 0;
   unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
   if(buffer) {
-    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    out.insert(out.end(), buffer, &buffer[buffersize]);
     lodepng_free(buffer);
   }
   return error;
@@ -6552,7 +6552,7 @@ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const
     state.info_raw.colortype = colortype;
     state.info_raw.bitdepth = bitdepth;
     size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
-    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    out.insert(out.end(), buffer, &buffer[buffersize]);
   }
   lodepng_free(buffer);
   return error;
@@ -6570,7 +6570,7 @@ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
   unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize);
   if(buffer && !error) {
     size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
-    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    out.insert(out.end(), buffer, &buffer[buffersize]);
   }
   lodepng_free(buffer);
   return error;
@@ -6602,7 +6602,7 @@ unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsign
   size_t buffersize;
   unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
   if(buffer) {
-    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    out.insert(out.end(), buffer, &buffer[buffersize]);
     lodepng_free(buffer);
   }
   return error;
@@ -6622,7 +6622,7 @@ unsigned encode(std::vector<unsigned char>& out,
   size_t buffersize;
   unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state);
   if(buffer) {
-    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    out.insert(out.end(), buffer, &buffer[buffersize]);
     lodepng_free(buffer);
   }
   return error;
diff --git a/lodepng.h b/lodepng.h
index e5e3ab4..fdafc77 100644
--- a/lodepng.h
+++ b/lodepng.h
@@ -1,5 +1,5 @@
 /*
-LodePNG version 20220618
+LodePNG version 20220717
 
 Copyright (c) 2005-2022 Lode Vandevenne
 
diff --git a/lodepng_util.cpp b/lodepng_util.cpp
index 95aaeb1..6d75c23 100644
--- a/lodepng_util.cpp
+++ b/lodepng_util.cpp
@@ -31,7 +31,7 @@ namespace lodepng {
 LodePNGInfo getPNGHeaderInfo(const std::vector<unsigned char>& png) {
   unsigned w, h;
   lodepng::State state;
-  lodepng_inspect(&w, &h, &state, &png[0], png.size());
+  lodepng_inspect(&w, &h, &state, png.empty() ? NULL : &png[0], png.size());
   return state.info_png;
 }
 
@@ -139,7 +139,7 @@ unsigned getFilterTypesInterlaced(std::vector<std::vector<unsigned char> >& filt
   lodepng::State state;
   unsigned w, h;
   unsigned error;
-  error = lodepng_inspect(&w, &h, &state, &png[0], png.size());
+  error = lodepng_inspect(&w, &h, &state, png.empty() ? NULL : &png[0], png.size());
 
   if(error) return 1;
 
@@ -173,7 +173,7 @@ unsigned getFilterTypesInterlaced(std::vector<std::vector<unsigned char> >& filt
 
   //Decompress all IDAT data (if the while loop ended early, this might fail)
   std::vector<unsigned char> data;
-  error = lodepng::decompress(data, &zdata[0], zdata.size());
+  error = lodepng::decompress(data, zdata.empty() ? NULL : &zdata[0], zdata.size());
 
   if(error) return 1;
 
@@ -230,7 +230,7 @@ unsigned getFilterTypes(std::vector<unsigned char>& filterTypes, const std::vect
     const unsigned shift1[8] = {1, 1, 1, 1, 1, 1, 1, 1};
     lodepng::State state;
     unsigned w, h;
-    lodepng_inspect(&w, &h, &state, &png[0], png.size());
+    lodepng_inspect(&w, &h, &state, png.empty() ? NULL : &png[0], png.size());
     const unsigned* column = w > 1 ? column1 : column0;
     const unsigned* shift = w > 1 ? shift1 : shift0;
     for(size_t i = 0; i < h; i++) {
@@ -1404,8 +1404,8 @@ unsigned convertRGBModel(unsigned char* out, const unsigned char* in,
     unsigned error = 0;
     float* xyz = (float*)lodepng_malloc(w * h * 4 * sizeof(float));
     float whitepoint[3];
-    error = convertToXYZ(&xyz[0], whitepoint, in, w, h, state_in);
-    if (!error) error = convertFromXYZ(out, &xyz[0], w, h, state_out, whitepoint, rendering_intent);
+    error = convertToXYZ(xyz, whitepoint, in, w, h, state_in);
+    if (!error) error = convertFromXYZ(out, xyz, w, h, state_out, whitepoint, rendering_intent);
     lodepng_free(xyz);
     return error;
   }
@@ -1691,7 +1691,7 @@ struct ExtractPNG { //PNG decoding and information extraction
   void decode(const unsigned char* in, size_t size) {
     error = 0;
     if(size == 0 || in == 0) { error = 48; return; } //the given data is empty
-    readPngHeader(&in[0], size); if(error) return;
+    readPngHeader(in, size); if(error) return;
     size_t pos = 33; //first byte of the first chunk after the header
     std::vector<unsigned char> idat; //the data from idat chunks
     bool IEND = false;
@@ -1754,7 +1754,7 @@ struct ExtractPNG { //PNG decoding and information extraction
 
 unsigned extractZlibInfo(std::vector<ZlibBlockInfo>& zlibinfo, const std::vector<unsigned char>& in) {
   ExtractPNG decoder(&zlibinfo);
-  decoder.decode(&in[0], in.size());
+  decoder.decode(in.empty() ? NULL : &in[0], in.size());
 
   return decoder.error ? 1 : 0;
 }