Upgrading libpng: Adding clean copy of libpng 1.5.10

This commit removes the previous version of the bundled libpng
(1.5.4), as well as all local modifications to it. It adds an
unmodified copy of the official libpng source distribution, except
that various extraneous files have been removed, as usual.

The patches required to build it in Qt will follow in separate
commit(s).

Change-Id: I90149f87fc889c44a3b60b21cdf755020f3a8e39
Reviewed-by: Kim M. Kalland <kim.kalland@nokia.com>

1 files changed, 183 insertions, 344 deletions

diff --git a/src/3rdparty/libpng/pngread.c b/src/3rdparty/libpng/pngread.c
index 2c8f2cd687..1d8c6b3346 100644
--- a/src/3rdparty/libpng/pngread.c
+++ b/src/3rdparty/libpng/pngread.c
@@ -1,8 +1,8 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.5.1 [$RDATE%]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.10 [March 8, 2012]
+ * Copyright (c) 1998-2012 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -47,12 +47,10 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
 
-   int i;
-
    png_debug(1, "in png_create_read_struct");
 
 #ifdef PNG_USER_MEM_SUPPORTED
@@ -69,29 +67,26 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
    png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
 
-#  ifdef PNG_USER_CHUNK_CACHE_MAX
    /* Added at libpng-1.2.43 and 1.4.0 */
    png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
-#  endif
 
-#  ifdef PNG_SET_USER_CHUNK_MALLOC_MAX
    /* Added at libpng-1.2.43 and 1.4.1 */
    png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
-#  endif
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
 /* Applications that neglect to set up their own setjmp() and then
-   encounter a png_error() will longjmp here.  Since the jmpbuf is
-   then meaningless we abort instead of returning. */
+ * encounter a png_error() will longjmp here.  Since the jmpbuf is
+ * then meaningless we abort instead of returning.
+ */
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
 #endif
       PNG_ABORT();
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif /* PNG_SETJMP_SUPPORTED */
 
@@ -101,54 +96,9 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if (user_png_ver)
-   {
-      i = 0;
-
-      do
-      {
-         if (user_png_ver[i] != png_libpng_ver[i])
-            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-      } while (png_libpng_ver[i++]);
-   }
-
-   else
-      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-
-
-   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
-   {
-     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
-      * we must recompile any applications that use any older library version.
-      * For versions after libpng 1.0, we will be compatible, so we need
-      * only check the first digit.
-      */
-      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
-          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
-          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
-      {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         char msg[80];
-         if (user_png_ver)
-         {
-            png_snprintf2(msg, 80,
-                "Application built with libpng-%.20s"
-                " but running with %.20s",
-                user_png_ver,
-                png_libpng_ver);
-            png_warning(png_ptr, msg);
-         }
-#else
-         png_warning(png_ptr,
-             "Incompatible libpng version in application and library");
-#endif
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-         png_ptr->flags = 0;
-#endif
-
-         png_cleanup_needed = 1;
-      }
-   }
+   /* Call the general version checker (shared with read and write code): */
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
 
    if (!png_cleanup_needed)
    {
@@ -237,89 +187,35 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
 
    for (;;)
    {
-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
-#ifdef PNG_READ_bKGD_SUPPORTED
-      PNG_bKGD;
-#endif
-#ifdef PNG_READ_cHRM_SUPPORTED
-      PNG_cHRM;
-#endif
-#ifdef PNG_READ_gAMA_SUPPORTED
-      PNG_gAMA;
-#endif
-#ifdef PNG_READ_hIST_SUPPORTED
-      PNG_hIST;
-#endif
-#ifdef PNG_READ_iCCP_SUPPORTED
-      PNG_iCCP;
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
-      PNG_iTXt;
-#endif
-#ifdef PNG_READ_oFFs_SUPPORTED
-      PNG_oFFs;
-#endif
-#ifdef PNG_READ_pCAL_SUPPORTED
-      PNG_pCAL;
-#endif
-#ifdef PNG_READ_pHYs_SUPPORTED
-      PNG_pHYs;
-#endif
-#ifdef PNG_READ_sBIT_SUPPORTED
-      PNG_sBIT;
-#endif
-#ifdef PNG_READ_sCAL_SUPPORTED
-      PNG_sCAL;
-#endif
-#ifdef PNG_READ_sPLT_SUPPORTED
-      PNG_sPLT;
-#endif
-#ifdef PNG_READ_sRGB_SUPPORTED
-      PNG_sRGB;
-#endif
-#ifdef PNG_READ_tEXt_SUPPORTED
-      PNG_tEXt;
-#endif
-#ifdef PNG_READ_tIME_SUPPORTED
-      PNG_tIME;
-#endif
-#ifdef PNG_READ_tRNS_SUPPORTED
-      PNG_tRNS;
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
-      PNG_zTXt;
-#endif
       png_uint_32 length = png_read_chunk_header(png_ptr);
-      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+      png_uint_32 chunk_name = png_ptr->chunk_name;
 
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
        */
-      if (!png_memcmp(chunk_name, png_IDAT, 4))
+      if (chunk_name == png_IDAT)
          if (png_ptr->mode & PNG_AFTER_IDAT)
             png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
-      if (!png_memcmp(chunk_name, png_IHDR, 4))
+      if (chunk_name == png_IHDR)
          png_handle_IHDR(png_ptr, info_ptr, length);
 
-      else if (!png_memcmp(chunk_name, png_IEND, 4))
+      else if (chunk_name == png_IEND)
          png_handle_IEND(png_ptr, info_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_handle_as_unknown(png_ptr, chunk_name))
+      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+         PNG_HANDLE_CHUNK_AS_DEFAULT)
       {
-         if (!png_memcmp(chunk_name, png_IDAT, 4))
+         if (chunk_name == png_IDAT)
             png_ptr->mode |= PNG_HAVE_IDAT;
 
          png_handle_unknown(png_ptr, info_ptr, length);
 
-         if (!png_memcmp(chunk_name, png_PLTE, 4))
+         if (chunk_name == png_PLTE)
             png_ptr->mode |= PNG_HAVE_PLTE;
 
-         else if (!png_memcmp(chunk_name, png_IDAT, 4))
+         else if (chunk_name == png_IDAT)
          {
             if (!(png_ptr->mode & PNG_HAVE_IHDR))
                png_error(png_ptr, "Missing IHDR before IDAT");
@@ -332,10 +228,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          }
       }
 #endif
-      else if (!png_memcmp(chunk_name, png_PLTE, 4))
+      else if (chunk_name == png_PLTE)
          png_handle_PLTE(png_ptr, info_ptr, length);
 
-      else if (!png_memcmp(chunk_name, png_IDAT, 4))
+      else if (chunk_name == png_IDAT)
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");
@@ -350,87 +246,87 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
       }
 
 #ifdef PNG_READ_bKGD_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_bKGD, 4))
+      else if (chunk_name == png_bKGD)
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_cHRM_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_cHRM, 4))
+      else if (chunk_name == png_cHRM)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_gAMA_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_gAMA, 4))
+      else if (chunk_name == png_gAMA)
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_hIST_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_hIST, 4))
+      else if (chunk_name == png_hIST)
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_oFFs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_oFFs, 4))
+      else if (chunk_name == png_oFFs)
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pCAL, 4))
+      else if (chunk_name == png_pCAL)
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sCAL, 4))
+      else if (chunk_name == png_sCAL)
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pHYs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pHYs, 4))
+      else if (chunk_name == png_pHYs)
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sBIT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sBIT, 4))
+      else if (chunk_name == png_sBIT)
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sRGB_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sRGB, 4))
+      else if (chunk_name == png_sRGB)
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iCCP_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iCCP, 4))
+      else if (chunk_name == png_iCCP)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sPLT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sPLT, 4))
+      else if (chunk_name == png_sPLT)
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tEXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tEXt, 4))
+      else if (chunk_name == png_tEXt)
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tIME_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tIME, 4))
+      else if (chunk_name == png_tIME)
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tRNS_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tRNS, 4))
+      else if (chunk_name == png_tRNS)
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_zTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_zTXt, 4))
+      else if (chunk_name == png_zTXt)
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iTXt, 4))
+      else if (chunk_name == png_iTXt)
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
 
@@ -449,15 +345,13 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
    if (png_ptr == NULL)
       return;
 
-   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
-      png_read_start_row(png_ptr);
-
-   else
-      png_warning(png_ptr,
-          "Ignoring extra png_read_update_info() call;"
-          " row buffer not reallocated");
+   png_read_start_row(png_ptr);
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    png_read_transform_info(png_ptr, info_ptr);
+#else
+   PNG_UNUSED(info_ptr)
+#endif
 }
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
@@ -471,15 +365,8 @@ png_start_read_image(png_structp png_ptr)
 {
    png_debug(1, "in png_start_read_image");
 
-   if (png_ptr == NULL)
-      return;
-
-   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
-      png_read_start_row(png_ptr);
-   else
-      png_warning(png_ptr,
-          "Ignoring extra png_start_read_image() call;"
-          " row buffer not reallocated");
+   if (png_ptr != NULL)
+     png_read_start_row(png_ptr);
 }
 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 
@@ -487,21 +374,30 @@ png_start_read_image(png_structp png_ptr)
 void PNGAPI
 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 {
-   PNG_IDAT;
-   PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
-       0xff};
-   PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
    int ret;
 
+   png_row_info row_info;
+
    if (png_ptr == NULL)
       return;
 
    png_debug2(1, "in png_read_row (row %lu, pass %d)",
        (unsigned long)png_ptr->row_number, png_ptr->pass);
 
+   /* png_read_start_row sets the information (in particular iwidth) for this
+    * interlace pass.
+    */
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
 
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
    {
    /* Check for transforms that have been set but were defined out */
@@ -543,7 +439,12 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    }
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
-   /* If interlaced and we do not need a new row, combine row and return */
+   /* If interlaced and we do not need a new row, combine row and return.
+    * Notice that the pixels we have from previous rows have been transformed
+    * already; we can only combine like with like (transformed or
+    * untransformed) and, because of the libpng API for interlaced images, this
+    * means we must transform before de-interlacing.
+    */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
    {
       switch (png_ptr->pass)
@@ -552,8 +453,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             if (png_ptr->row_number & 0x07)
             {
                if (dsp_row != NULL)
-                  png_combine_row(png_ptr, dsp_row,
-                     png_pass_dsp_mask[png_ptr->pass]);
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
                png_read_finish_row(png_ptr);
                return;
             }
@@ -563,8 +463,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
             {
                if (dsp_row != NULL)
-                  png_combine_row(png_ptr, dsp_row,
-                      png_pass_dsp_mask[png_ptr->pass]);
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
 
                png_read_finish_row(png_ptr);
                return;
@@ -575,8 +474,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             if ((png_ptr->row_number & 0x07) != 4)
             {
                if (dsp_row != NULL && (png_ptr->row_number & 4))
-                  png_combine_row(png_ptr, dsp_row,
-                      png_pass_dsp_mask[png_ptr->pass]);
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
 
                png_read_finish_row(png_ptr);
                return;
@@ -587,8 +485,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             if ((png_ptr->row_number & 3) || png_ptr->width < 3)
             {
                if (dsp_row != NULL)
-                  png_combine_row(png_ptr, dsp_row,
-                      png_pass_dsp_mask[png_ptr->pass]);
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
 
                png_read_finish_row(png_ptr);
                return;
@@ -599,8 +496,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             if ((png_ptr->row_number & 3) != 2)
             {
                if (dsp_row != NULL && (png_ptr->row_number & 2))
-                  png_combine_row(png_ptr, dsp_row,
-                      png_pass_dsp_mask[png_ptr->pass]);
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
 
                png_read_finish_row(png_ptr);
                return;
@@ -610,8 +506,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             if ((png_ptr->row_number & 1) || png_ptr->width < 2)
             {
                if (dsp_row != NULL)
-                  png_combine_row(png_ptr, dsp_row,
-                      png_pass_dsp_mask[png_ptr->pass]);
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
 
                png_read_finish_row(png_ptr);
                return;
@@ -647,7 +542,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             png_crc_finish(png_ptr, 0);
 
             png_ptr->idat_size = png_read_chunk_header(png_ptr);
-            if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+            if (png_ptr->chunk_name != png_IDAT)
                png_error(png_ptr, "Not enough image data");
          }
          png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
@@ -677,33 +572,47 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 
    } while (png_ptr->zstream.avail_out);
 
-   png_ptr->row_info.color_type = png_ptr->color_type;
-   png_ptr->row_info.width = png_ptr->iwidth;
-   png_ptr->row_info.channels = png_ptr->channels;
-   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
-   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
-   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
-       png_ptr->row_info.width);
-
-   if (png_ptr->row_buf[0])
-   png_read_filter_row(png_ptr, &(png_ptr->row_info),
-       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
-       (int)(png_ptr->row_buf[0]));
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
 
-   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * it may not be in the future, so this was changed just to copy the
+    * interlaced count:
+    */
+   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
        (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
-      png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
    }
 #endif
 
 
-   if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
-      png_do_read_transformations(png_ptr);
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   if (png_ptr->transformations)
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "sequential row overflow");
+   }
+
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal sequential row size calculation error");
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Blow up interlaced rows to full size */
@@ -711,27 +620,24 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
       (png_ptr->transformations & PNG_INTERLACE))
    {
       if (png_ptr->pass < 6)
-         /* Old interface (pre-1.0.9):
-          * png_do_read_interlace(&(png_ptr->row_info),
-          *    png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
-          */
-         png_do_read_interlace(png_ptr);
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+            png_ptr->transformations);
 
       if (dsp_row != NULL)
-         png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]);
+         png_combine_row(png_ptr, dsp_row, 1/*display*/);
 
       if (row != NULL)
-         png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]);
+         png_combine_row(png_ptr, row, 0/*row*/);
    }
 
    else
 #endif
    {
       if (row != NULL)
-         png_combine_row(png_ptr, row, 0xff);
+         png_combine_row(png_ptr, row, -1/*ignored*/);
 
       if (dsp_row != NULL)
-         png_combine_row(png_ptr, dsp_row, 0xff);
+         png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
    }
    png_read_finish_row(png_ptr);
 
@@ -895,87 +801,40 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 
    png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
 
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   /* Report invalid palette index; added at libng-1.5.10 */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+      png_ptr->num_palette_max > png_ptr->num_palette)
+     png_benign_error(png_ptr, "Read palette index exceeding num_palette");
+#endif
+
    do
    {
-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
-#ifdef PNG_READ_bKGD_SUPPORTED
-      PNG_bKGD;
-#endif
-#ifdef PNG_READ_cHRM_SUPPORTED
-      PNG_cHRM;
-#endif
-#ifdef PNG_READ_gAMA_SUPPORTED
-      PNG_gAMA;
-#endif
-#ifdef PNG_READ_hIST_SUPPORTED
-      PNG_hIST;
-#endif
-#ifdef PNG_READ_iCCP_SUPPORTED
-      PNG_iCCP;
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
-      PNG_iTXt;
-#endif
-#ifdef PNG_READ_oFFs_SUPPORTED
-      PNG_oFFs;
-#endif
-#ifdef PNG_READ_pCAL_SUPPORTED
-      PNG_pCAL;
-#endif
-#ifdef PNG_READ_pHYs_SUPPORTED
-      PNG_pHYs;
-#endif
-#ifdef PNG_READ_sBIT_SUPPORTED
-      PNG_sBIT;
-#endif
-#ifdef PNG_READ_sCAL_SUPPORTED
-      PNG_sCAL;
-#endif
-#ifdef PNG_READ_sPLT_SUPPORTED
-      PNG_sPLT;
-#endif
-#ifdef PNG_READ_sRGB_SUPPORTED
-      PNG_sRGB;
-#endif
-#ifdef PNG_READ_tEXt_SUPPORTED
-      PNG_tEXt;
-#endif
-#ifdef PNG_READ_tIME_SUPPORTED
-      PNG_tIME;
-#endif
-#ifdef PNG_READ_tRNS_SUPPORTED
-      PNG_tRNS;
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
-      PNG_zTXt;
-#endif
       png_uint_32 length = png_read_chunk_header(png_ptr);
-      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+      png_uint_32 chunk_name = png_ptr->chunk_name;
 
-      if (!png_memcmp(chunk_name, png_IHDR, 4))
+      if (chunk_name == png_IHDR)
          png_handle_IHDR(png_ptr, info_ptr, length);
 
-      else if (!png_memcmp(chunk_name, png_IEND, 4))
+      else if (chunk_name == png_IEND)
          png_handle_IEND(png_ptr, info_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_handle_as_unknown(png_ptr, chunk_name))
+      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+         PNG_HANDLE_CHUNK_AS_DEFAULT)
       {
-         if (!png_memcmp(chunk_name, png_IDAT, 4))
+         if (chunk_name == png_IDAT)
          {
             if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
                png_benign_error(png_ptr, "Too many IDATs found");
          }
          png_handle_unknown(png_ptr, info_ptr, length);
-         if (!png_memcmp(chunk_name, png_PLTE, 4))
+         if (chunk_name == png_PLTE)
             png_ptr->mode |= PNG_HAVE_PLTE;
       }
 #endif
 
-      else if (!png_memcmp(chunk_name, png_IDAT, 4))
+      else if (chunk_name == png_IDAT)
       {
          /* Zero length IDATs are legal after the last IDAT has been
           * read, but not after other chunks have been read.
@@ -985,91 +844,91 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 
          png_crc_finish(png_ptr, length);
       }
-      else if (!png_memcmp(chunk_name, png_PLTE, 4))
+      else if (chunk_name == png_PLTE)
          png_handle_PLTE(png_ptr, info_ptr, length);
 
 #ifdef PNG_READ_bKGD_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_bKGD, 4))
+      else if (chunk_name == png_bKGD)
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_cHRM_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_cHRM, 4))
+      else if (chunk_name == png_cHRM)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_gAMA_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_gAMA, 4))
+      else if (chunk_name == png_gAMA)
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_hIST_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_hIST, 4))
+      else if (chunk_name == png_hIST)
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_oFFs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_oFFs, 4))
+      else if (chunk_name == png_oFFs)
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pCAL, 4))
+      else if (chunk_name == png_pCAL)
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sCAL, 4))
+      else if (chunk_name == png_sCAL)
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pHYs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pHYs, 4))
+      else if (chunk_name == png_pHYs)
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sBIT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sBIT, 4))
+      else if (chunk_name == png_sBIT)
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sRGB_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sRGB, 4))
+      else if (chunk_name == png_sRGB)
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iCCP_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iCCP, 4))
+      else if (chunk_name == png_iCCP)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sPLT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sPLT, 4))
+      else if (chunk_name == png_sPLT)
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tEXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tEXt, 4))
+      else if (chunk_name == png_tEXt)
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tIME_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tIME, 4))
+      else if (chunk_name == png_tIME)
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tRNS_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tRNS, 4))
+      else if (chunk_name == png_tRNS)
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_zTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_zTXt, 4))
+      else if (chunk_name == png_zTXt)
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iTXt, 4))
+      else if (chunk_name == png_iTXt)
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
 
@@ -1161,7 +1020,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    jmp_buf tmp_jmp;
 #endif
    png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_error_ptr warning_fn;
+#endif
    png_voidp error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn;
@@ -1175,9 +1036,13 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    if (end_info_ptr != NULL)
       png_info_destroy(png_ptr, end_info_ptr);
 
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_destroy_gamma_table(png_ptr);
+#endif
+
    png_free(png_ptr, png_ptr->zbuf);
    png_free(png_ptr, png_ptr->big_row_buf);
-   png_free(png_ptr, png_ptr->prev_row);
+   png_free(png_ptr, png_ptr->big_prev_row);
    png_free(png_ptr, png_ptr->chunkdata);
 
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
@@ -1185,15 +1050,6 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    png_free(png_ptr, png_ptr->quantize_index);
 #endif
 
-#ifdef PNG_READ_GAMMA_SUPPORTED
-   png_free(png_ptr, png_ptr->gamma_table);
-#endif
-
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-   png_free(png_ptr, png_ptr->gamma_from_1);
-   png_free(png_ptr, png_ptr->gamma_to_1);
-#endif
-
    if (png_ptr->free_me & PNG_FREE_PLTE)
       png_zfree(png_ptr, png_ptr->palette);
    png_ptr->free_me &= ~PNG_FREE_PLTE;
@@ -1211,67 +1067,23 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    png_ptr->free_me &= ~PNG_FREE_HIST;
 #endif
 
-#ifdef PNG_READ_GAMMA_SUPPORTED
-   if (png_ptr->gamma_16_table != NULL)
-   {
-      int i;
-      int istop = (1 << (8 - png_ptr->gamma_shift));
-      for (i = 0; i < istop; i++)
-      {
-         png_free(png_ptr, png_ptr->gamma_16_table[i]);
-      }
-   png_free(png_ptr, png_ptr->gamma_16_table);
-   }
-
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-   if (png_ptr->gamma_16_from_1 != NULL)
-   {
-      int i;
-      int istop = (1 << (8 - png_ptr->gamma_shift));
-      for (i = 0; i < istop; i++)
-      {
-         png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
-      }
-   png_free(png_ptr, png_ptr->gamma_16_from_1);
-   }
-   if (png_ptr->gamma_16_to_1 != NULL)
-   {
-      int i;
-      int istop = (1 << (8 - png_ptr->gamma_shift));
-      for (i = 0; i < istop; i++)
-      {
-         png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
-      }
-   png_free(png_ptr, png_ptr->gamma_16_to_1);
-   }
-#endif
-#endif
-
-#ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_free(png_ptr, png_ptr->time_buffer);
-#endif
-
    inflateEnd(&png_ptr->zstream);
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
    png_free(png_ptr, png_ptr->save_buffer);
 #endif
 
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-#ifdef PNG_TEXT_SUPPORTED
-   png_free(png_ptr, png_ptr->current_text);
-#endif /* PNG_TEXT_SUPPORTED */
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
    /* Save the important info out of the png_struct, in case it is
     * being used again.
     */
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    warning_fn = png_ptr->warning_fn;
+#endif
    error_ptr = png_ptr->error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    free_fn = png_ptr->free_fn;
@@ -1280,14 +1092,16 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#endif
    png_ptr->error_ptr = error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr->free_fn = free_fn;
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 
 }
@@ -1311,7 +1125,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 {
    int row;
 
-   if (png_ptr == NULL)
+   if (png_ptr == NULL || info_ptr == NULL)
       return;
 
    /* png_read_info() gives us all of the information from the
@@ -1323,8 +1137,22 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 
    /* -------------- image transformations start here ------------------- */
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-   /* Tell libpng to strip 16 bit/color files down to 8 bits per color.
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+    */
+   if (transforms & PNG_TRANSFORM_SCALE_16)
+   {
+     /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+      * did in earlier versions, while "scale_16" is now more accurate.
+      */
+      png_set_scale_16(png_ptr);
+   }
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+    * latter by doing SCALE first.  This is ok and allows apps not to check for
+    * which is supported to get the right answer.
     */
    if (transforms & PNG_TRANSFORM_STRIP_16)
       png_set_strip_16(png_ptr);
@@ -1405,7 +1233,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_READ_SWAP_SUPPORTED
-   /* Swap bytes of 16 bit files to least significant byte first */
+   /* Swap bytes of 16-bit files to least significant byte first */
    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
       png_set_swap(png_ptr);
 #endif
@@ -1424,8 +1252,19 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
       png_set_gray_to_rgb(png_ptr);
 #endif
 
+/* Added at libpng-1.5.4 */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (transforms & PNG_TRANSFORM_EXPAND_16)
+      png_set_expand_16(png_ptr);
+#endif
+
    /* We don't handle adding filler bytes */
 
+   /* We use png_read_image and rely on that for interlace handling, but we also
+    * call png_read_update_info therefore must turn on interlace handling now:
+    */
+   (void)png_set_interlace_handling(png_ptr);
+
    /* Optional call to gamma correct and add the background to the palette
     * and update info structure.  REQUIRED if you are expecting libpng to
     * update the palette for you (i.e., you selected such a transform above).