output palette fix

3 files changed, 103 insertions, 15 deletions

diff --git a/lodepng.cpp b/lodepng.cpp
index 643bfd5..a5a5b78 100644
--- a/lodepng.cpp
+++ b/lodepng.cpp
@@ -1,5 +1,5 @@
 /*
-LodePNG version 20150912
+LodePNG version 20151024
 
 Copyright (c) 2005-2015 Lode Vandevenne
 
@@ -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 = "20150912";
+const char* LODEPNG_VERSION_STRING = "20151024";
 
 /*
 This source file is built up in the following large parts. The code sections
@@ -779,7 +779,7 @@ unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequen
   {
     if(frequencies[i] > 0)
     {
-      leaves[numpresent].weight = frequencies[i];
+      leaves[numpresent].weight = (int)frequencies[i];
       leaves[numpresent].index = i;
       ++numpresent;
     }
@@ -832,7 +832,7 @@ unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequen
       }
 
       /*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/
-      for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, maxbitlen - 1, i);
+      for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i);
 
       for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail)
       {
@@ -2598,10 +2598,15 @@ static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColo
     if(a->key_g != b->key_g) return 0;
     if(a->key_b != b->key_b) return 0;
   }
-  if(a->palettesize != b->palettesize) return 0;
-  for(i = 0; i != a->palettesize * 4; ++i)
-  {
-    if(a->palette[i] != b->palette[i]) return 0;
+  /*if one of the palette sizes is 0, then we consider it to be the same as the
+  other: it means that e.g. the palette was not given by the user and should be
+  considered the same as the palette inside the PNG.*/
+  if(1/*a->palettesize != 0 && b->palettesize != 0*/) {
+    if(a->palettesize != b->palettesize) return 0;
+    for(i = 0; i != a->palettesize * 4; ++i)
+    {
+      if(a->palette[i] != b->palette[i]) return 0;
+    }
   }
   return 1;
 }
@@ -3419,7 +3424,7 @@ static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned s
 }
 
 unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
-                         LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
                          unsigned w, unsigned h)
 {
   size_t i;
@@ -3435,12 +3440,21 @@ unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
 
   if(mode_out->colortype == LCT_PALETTE)
   {
+    size_t palettesize = mode_out->palettesize;
+    const unsigned char* palette = mode_out->palette;
     size_t palsize = 1u << mode_out->bitdepth;
-    if(mode_out->palettesize < palsize) palsize = mode_out->palettesize;
+    /*if the user specified output palette but did not give the values, assume
+    they want the values of the input color type (assuming that one is palette).
+    Note that we never create a new palette ourselves.*/
+    if(palettesize == 0) {
+      palettesize = mode_in->palettesize;
+      palette = mode_in->palette;
+    }
+    if(palettesize < palsize) palsize = palettesize;
     color_tree_init(&tree);
     for(i = 0; i != palsize; ++i)
     {
-      unsigned char* p = &mode_out->palette[i * 4];
+      const unsigned char* p = &palette[i * 4];
       color_tree_add(&tree, p[0], p[1], p[2], p[3], i);
     }
   }
@@ -3468,7 +3482,7 @@ unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
     for(i = 0; i != numpixels; ++i)
     {
       getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
-      rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
+      CERROR_TRY_RETURN(rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a));
     }
   }
 
@@ -3477,7 +3491,7 @@ unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
     color_tree_cleanup(&tree);
   }
 
-  return 0; /*no error (this function currently never has one, but maybe OOM detection added later.)*/
+  return 0; /*no error*/
 }
 
 #ifdef LODEPNG_COMPILE_ENCODER
diff --git a/lodepng.h b/lodepng.h
index 86e56a3..86c24f9 100644
--- a/lodepng.h
+++ b/lodepng.h
@@ -1,5 +1,5 @@
 /*
-LodePNG version 20150912
+LodePNG version 20151024
 
 Copyright (c) 2005-2015 Lode Vandevenne
 
@@ -508,7 +508,7 @@ For 16-bit per channel colors, uses big endian format like PNG does.
 Return value is LodePNG error code
 */
 unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
-                         LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
                          unsigned w, unsigned h);
 
 #ifdef LODEPNG_COMPILE_DECODER
@@ -1564,6 +1564,7 @@ yyyymmdd.
 Some changes aren't backwards compatible. Those are indicated with a (!)
 symbol.
 
+*) 24 okt 2015: Bugfix with decoding to palette output.
 *) 18 apr 2015: Boundary PM instead of just package-merge for faster encoding.
 *) 23 aug 2014: Reduced needless memory usage of decoder.
 *) 28 jun 2014: Removed fix_png setting, always support palette OOB for
diff --git a/lodepng_unittest.cpp b/lodepng_unittest.cpp
index 92fc370..6d9cbab 100644
--- a/lodepng_unittest.cpp
+++ b/lodepng_unittest.cpp
@@ -1799,6 +1799,77 @@ void testAutoColorModels()
   testAutoColorModel(alpha16, 16, LCT_RGBA, 16, false);
 }
 
+void testPaletteToPaletteDecode() {
+  std::cout << "testPaletteToPaletteDecode" << std::endl;
+  // It's a bit big for a 2x2 image... but this tests needs one with 256 palette entries in it.
+  std::string base64 = "iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAMAAABFaP0WAAAAA3NCSVQICAjb4U/gAAADAFBMVEUA"
+                       "AAAAADMAAGYAAJkAAMwAAP8AMwAAMzMAM2YAM5kAM8wAM/8AZgAAZjMAZmYAZpkAZswAZv8AmQAA"
+                       "mTMAmWYAmZkAmcwAmf8AzAAAzDMAzGYAzJkAzMwAzP8A/wAA/zMA/2YA/5kA/8wA//8zAAAzADMz"
+                       "AGYzAJkzAMwzAP8zMwAzMzMzM2YzM5kzM8wzM/8zZgAzZjMzZmYzZpkzZswzZv8zmQAzmTMzmWYz"
+                       "mZkzmcwzmf8zzAAzzDMzzGYzzJkzzMwzzP8z/wAz/zMz/2Yz/5kz/8wz//9mAABmADNmAGZmAJlm"
+                       "AMxmAP9mMwBmMzNmM2ZmM5lmM8xmM/9mZgBmZjNmZmZmZplmZsxmZv9mmQBmmTNmmWZmmZlmmcxm"
+                       "mf9mzABmzDNmzGZmzJlmzMxmzP9m/wBm/zNm/2Zm/5lm/8xm//+ZAACZADOZAGaZAJmZAMyZAP+Z"
+                       "MwCZMzOZM2aZM5mZM8yZM/+ZZgCZZjOZZmaZZpmZZsyZZv+ZmQCZmTOZmWaZmZmZmcyZmf+ZzACZ"
+                       "zDOZzGaZzJmZzMyZzP+Z/wCZ/zOZ/2aZ/5mZ/8yZ///MAADMADPMAGbMAJnMAMzMAP/MMwDMMzPM"
+                       "M2bMM5nMM8zMM//MZgDMZjPMZmbMZpnMZszMZv/MmQDMmTPMmWbMmZnMmczMmf/MzADMzDPMzGbM"
+                       "zJnMzMzMzP/M/wDM/zPM/2bM/5nM/8zM////AAD/ADP/AGb/AJn/AMz/AP//MwD/MzP/M2b/M5n/"
+                       "M8z/M///ZgD/ZjP/Zmb/Zpn/Zsz/Zv//mQD/mTP/mWb/mZn/mcz/mf//zAD/zDP/zGb/zJn/zMz/"
+                       "zP///wD//zP//2b//5n//8z///8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+                       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+                       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABlenwdAAABAHRSTlP/////////////////////////"
+                       "////////////////////////////////////////////////////////////////////////////"
+                       "////////////////////////////////////////////////////////////////////////////"
+                       "////////////////////////////////////////////////////////////////////////////"
+                       "//////////////////////////////////8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+                       "AAAAAAAAAAAAG8mZagAAAAlwSFlzAAAOTQAADpwB3vacVwAAAA5JREFUCJlj2CLHwHodAATjAa+k"
+                       "lTE5AAAAAElFTkSuQmCC";
+  std::vector<unsigned char> png;
+  fromBase64(png, base64);
+
+  std::vector<unsigned char> image;
+  unsigned width, height;
+  unsigned error = lodepng::decode(image, width, height, png, LCT_PALETTE, 8);
+  ASSERT_EQUALS(0, error);
+  ASSERT_EQUALS(2, width);
+  ASSERT_EQUALS(2, height);
+  ASSERT_EQUALS(180, image[0]);
+  ASSERT_EQUALS(30, image[1]);
+  ASSERT_EQUALS(5, image[2]);
+  ASSERT_EQUALS(215, image[3]);
+}
+
+//2-bit palette
+void testPaletteToPaletteDecode2() {
+  std::cout << "testPaletteToPaletteDecode2" << std::endl;
+  std::string base64 = "iVBORw0KGgoAAAANSUhEUgAAACAAAAAgAgMAAAAOFJJnAAAADFBMVEX/AAAA/wAAAP/////7AGD2AAAAE0lEQVR4AWMQhAKG3VCALDIqAgDl2WYBCQHY9gAAAABJRU5ErkJggg==";
+  std::vector<unsigned char> png;
+  fromBase64(png, base64);
+
+  std::vector<unsigned char> image;
+  unsigned width, height;
+  unsigned error = lodepng::decode(image, width, height, png, LCT_PALETTE, 8);
+  ASSERT_EQUALS(0, error);
+  ASSERT_EQUALS(32, width);
+  ASSERT_EQUALS(32, height);
+  ASSERT_EQUALS(0, image[0]);
+  ASSERT_EQUALS(1, image[1]);
+
+  //Now add a user-specified output palette, that differs from the input palette. That should give error 82.
+  LodePNGState state;
+  lodepng_state_init(&state);
+  state.info_raw.colortype = LCT_PALETTE;
+  state.info_raw.bitdepth = 8;
+  lodepng_palette_add(&state.info_raw, 0, 0, 0, 255);
+  lodepng_palette_add(&state.info_raw, 1, 1, 1, 255);
+  lodepng_palette_add(&state.info_raw, 2, 2, 2, 255);
+  lodepng_palette_add(&state.info_raw, 3, 3, 3, 255);
+  unsigned char* image2 = 0;
+  unsigned error2 = lodepng_decode(&image2, &width, &height, &state, &png[0], png.size());
+  ASSERT_EQUALS(82, error2);
+  lodepng_state_cleanup(&state);
+  free(image2);
+}
+
 void doMain()
 {
   //PNG
@@ -1809,6 +1880,8 @@ void doMain()
   testPredefinedFilters();
   testFuzzing();
   testWrongWindowSizeGivesError();
+  testPaletteToPaletteDecode();
+  testPaletteToPaletteDecode2();
 
   //Colors
   testColorKeyConvert();