X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/1f0299c17dc878540bf190c290392db241b425ad..63482fd5e8b546fef76694a4e642d7b219ac4d86:/src/png/pngrutil.c

diff --git a/src/png/pngrutil.c b/src/png/pngrutil.c
index e127c87995..99bca1933b 100644
--- a/src/png/pngrutil.c
+++ b/src/png/pngrutil.c
@@ -1,28 +1,65 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * libpng 1.0.1
+ * Last changed in libpng 1.2.19 August 19, 2007
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 15, 1998
+ * Copyright (c) 1998-2007 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.)
  *
- * This file contains routines which are only called from within
+ * This file contains routines that are only called from within
  * libpng itself during the course of reading an image.
  */
 
 #define PNG_INTERNAL
-#include "../png/png.h"
+#include "png.h"
 
+#if defined(PNG_READ_SUPPORTED)
+
+#if defined(_WIN32_WCE) && (_WIN32_WCE<0x500)
+#  define WIN32_WCE_OLD
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+#  if defined(WIN32_WCE_OLD)
+/* strtod() function is not supported on WindowsCE */
+__inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, char **endptr)
+{
+   double result = 0;
+   int len;
+   wchar_t *str, *end;
+
+   len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
+   str = (wchar_t *)png_malloc(png_ptr, len * sizeof(wchar_t));
+   if ( NULL != str )
+   {
+      MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
+      result = wcstod(str, &end);
+      len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL);
+      *endptr = (char *)nptr + (png_strlen(nptr) - len + 1);
+      png_free(png_ptr, str);
+   }
+   return result;
+}
+#  else
+#    define png_strtod(p,a,b) strtod(a,b)
+#  endif
+#endif
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_structp png_ptr, png_bytep buf)
+{
+   png_uint_32 i = png_get_uint_32(buf);
+   if (i > PNG_UINT_31_MAX)
+     png_error(png_ptr, "PNG unsigned integer out of range.");
+   return (i);
+}
 #ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
-/* Grab an unsigned 32-bit integer from a buffer in big endian format. */
-png_uint_32
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 PNGAPI
 png_get_uint_32(png_bytep buf)
 {
-   png_uint_32 i;
-
-   i = ((png_uint_32)(*buf) << 24) +
+   png_uint_32 i = ((png_uint_32)(*buf) << 24) +
       ((png_uint_32)(*(buf + 1)) << 16) +
       ((png_uint_32)(*(buf + 2)) << 8) +
       (png_uint_32)(*(buf + 3));
@@ -30,31 +67,25 @@ png_get_uint_32(png_bytep buf)
    return (i);
 }
 
-#if defined(PNG_READ_pCAL_SUPPORTED)
-/* Grab a signed 32-bit integer from a buffer in big endian format.  The
+/* Grab a signed 32-bit integer from a buffer in big-endian format.  The
  * data is stored in the PNG file in two's complement format, and it is
  * assumed that the machine format for signed integers is the same. */
-png_int_32
+png_int_32 PNGAPI
 png_get_int_32(png_bytep buf)
 {
-   png_int_32 i;
-
-   i = ((png_int_32)(*buf) << 24) +
+   png_int_32 i = ((png_int_32)(*buf) << 24) +
       ((png_int_32)(*(buf + 1)) << 16) +
       ((png_int_32)(*(buf + 2)) << 8) +
       (png_int_32)(*(buf + 3));
 
    return (i);
 }
-#endif /* PNG_READ_pCAL_SUPPORTED */
 
-/* Grab an unsigned 16-bit integer from a buffer in big endian format. */
-png_uint_16
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 PNGAPI
 png_get_uint_16(png_bytep buf)
 {
-   png_uint_16 i;
-
-   i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
+   png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
       (png_uint_16)(*(buf + 1)));
 
    return (i);
@@ -62,9 +93,10 @@ png_get_uint_16(png_bytep buf)
 #endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
 
 /* Read data, and (optionally) run it through the CRC. */
-void
+void /* PRIVATE */
 png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
 {
+   if(png_ptr == NULL) return;
    png_read_data(png_ptr, buf, length);
    png_calculate_crc(png_ptr, buf, length);
 }
@@ -73,26 +105,27 @@ png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
    are reading a ancillary or critical chunk, and how the program has set
    things up, we may calculate the CRC on the data and print a message.
    Returns '1' if there was a CRC error, '0' otherwise. */
-int
+int /* PRIVATE */
 png_crc_finish(png_structp png_ptr, png_uint_32 skip)
 {
-   png_uint_32 i;
+   png_size_t i;
+   png_size_t istop = png_ptr->zbuf_size;
 
-   for (i = skip; i > (png_uint_32)png_ptr->zbuf_size; i -= png_ptr->zbuf_size)
+   for (i = (png_size_t)skip; i > istop; i -= istop)
    {
       png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
    }
    if (i)
    {
-      png_crc_read(png_ptr, png_ptr->zbuf, (png_size_t)i);
+      png_crc_read(png_ptr, png_ptr->zbuf, i);
    }
 
    if (png_crc_error(png_ptr))
    {
-      if ((png_ptr->chunk_name[0] & 0x20 &&                /* Ancillary */
+      if (((png_ptr->chunk_name[0] & 0x20) &&                /* Ancillary */
            !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
           (!(png_ptr->chunk_name[0] & 0x20) &&             /* Critical  */
-           png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
+          (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
       {
          png_chunk_warning(png_ptr, "CRC error");
       }
@@ -108,7 +141,7 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip)
 
 /* Compare the CRC stored in the PNG file with that calculated by libpng from
    the data it has read thus far. */
-int
+int /* PRIVATE */
 png_crc_error(png_structp png_ptr)
 {
    png_byte crc_bytes[4];
@@ -138,9 +171,180 @@ png_crc_error(png_structp png_ptr)
       return (0);
 }
 
+#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
+    defined(PNG_READ_iCCP_SUPPORTED)
+/*
+ * Decompress trailing data in a chunk.  The assumption is that chunkdata
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part.  What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+png_charp /* PRIVATE */
+png_decompress_chunk(png_structp png_ptr, int comp_type,
+                              png_charp chunkdata, png_size_t chunklength,
+                              png_size_t prefix_size, png_size_t *newlength)
+{
+   static PNG_CONST char msg[] = "Error decoding compressed text";
+   png_charp text;
+   png_size_t text_size;
+
+   if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+   {
+      int ret = Z_OK;
+      png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size);
+      png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
+      png_ptr->zstream.next_out = png_ptr->zbuf;
+      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+
+      text_size = 0;
+      text = NULL;
+
+      while (png_ptr->zstream.avail_in)
+      {
+         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+         if (ret != Z_OK && ret != Z_STREAM_END)
+         {
+            if (png_ptr->zstream.msg != NULL)
+               png_warning(png_ptr, png_ptr->zstream.msg);
+            else
+               png_warning(png_ptr, msg);
+            inflateReset(&png_ptr->zstream);
+            png_ptr->zstream.avail_in = 0;
+
+            if (text ==  NULL)
+            {
+               text_size = prefix_size + png_sizeof(msg) + 1;
+               text = (png_charp)png_malloc_warn(png_ptr, text_size);
+               if (text ==  NULL)
+                 {
+                    png_free(png_ptr,chunkdata);
+                    png_error(png_ptr,"Not enough memory to decompress chunk");
+                 }
+               png_memcpy(text, chunkdata, prefix_size);
+            }
+
+            text[text_size - 1] = 0x00;
+
+            /* Copy what we can of the error message into the text chunk */
+            text_size = (png_size_t)(chunklength - (text - chunkdata) - 1);
+            text_size = png_sizeof(msg) > text_size ? text_size :
+               png_sizeof(msg);
+            png_memcpy(text + prefix_size, msg, text_size + 1);
+            break;
+         }
+         if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
+         {
+            if (text == NULL)
+            {
+               text_size = prefix_size +
+                   png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+               text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
+               if (text ==  NULL)
+                 {
+                    png_free(png_ptr,chunkdata);
+                    png_error(png_ptr,"Not enough memory to decompress chunk.");
+                 }
+               png_memcpy(text + prefix_size, png_ptr->zbuf,
+                    text_size - prefix_size);
+               png_memcpy(text, chunkdata, prefix_size);
+               *(text + text_size) = 0x00;
+            }
+            else
+            {
+               png_charp tmp;
+
+               tmp = text;
+               text = (png_charp)png_malloc_warn(png_ptr,
+                  (png_uint_32)(text_size +
+                  png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
+               if (text == NULL)
+               {
+                  png_free(png_ptr, tmp);
+                  png_free(png_ptr, chunkdata);
+                  png_error(png_ptr,"Not enough memory to decompress chunk..");
+               }
+               png_memcpy(text, tmp, text_size);
+               png_free(png_ptr, tmp);
+               png_memcpy(text + text_size, png_ptr->zbuf,
+                  (png_ptr->zbuf_size - png_ptr->zstream.avail_out));
+               text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+               *(text + text_size) = 0x00;
+            }
+            if (ret == Z_STREAM_END)
+               break;
+            else
+            {
+               png_ptr->zstream.next_out = png_ptr->zbuf;
+               png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+            }
+         }
+      }
+      if (ret != Z_STREAM_END)
+      {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+         char umsg[52];
+
+         if (ret == Z_BUF_ERROR)
+            png_snprintf(umsg, 52,
+                "Buffer error in compressed datastream in %s chunk",
+                png_ptr->chunk_name);
+         else if (ret == Z_DATA_ERROR)
+            png_snprintf(umsg, 52,
+                "Data error in compressed datastream in %s chunk",
+                png_ptr->chunk_name);
+         else
+            png_snprintf(umsg, 52,
+                "Incomplete compressed datastream in %s chunk",
+                png_ptr->chunk_name);
+         png_warning(png_ptr, umsg);
+#else
+         png_warning(png_ptr,
+            "Incomplete compressed datastream in chunk other than IDAT");
+#endif
+         text_size=prefix_size;
+         if (text ==  NULL)
+         {
+            text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
+            if (text == NULL)
+              {
+                png_free(png_ptr, chunkdata);
+                png_error(png_ptr,"Not enough memory for text.");
+              }
+            png_memcpy(text, chunkdata, prefix_size);
+         }
+         *(text + text_size) = 0x00;
+      }
+
+      inflateReset(&png_ptr->zstream);
+      png_ptr->zstream.avail_in = 0;
+
+      png_free(png_ptr, chunkdata);
+      chunkdata = text;
+      *newlength=text_size;
+   }
+   else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+   {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+      char umsg[50];
+
+      png_snprintf(umsg, 50,
+         "Unknown zTXt compression type %d", comp_type);
+      png_warning(png_ptr, umsg);
+#else
+      png_warning(png_ptr, "Unknown zTXt compression type");
+#endif
+
+      *(chunkdata + prefix_size) = 0x00;
+      *newlength=prefix_size;
+   }
+
+   return chunkdata;
+}
+#endif
 
 /* read and check the IDHR chunk */
-void
+void /* PRIVATE */
 png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_byte buf[13];
@@ -150,7 +354,7 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    png_debug(1, "in png_handle_IHDR\n");
 
-   if (png_ptr->mode != PNG_BEFORE_IHDR)
+   if (png_ptr->mode & PNG_HAVE_IHDR)
       png_error(png_ptr, "Out of place IHDR");
 
    /* check the length */
@@ -162,49 +366,24 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    png_crc_read(png_ptr, buf, 13);
    png_crc_finish(png_ptr, 0);
 
-   width = png_get_uint_32(buf);
-   height = png_get_uint_32(buf + 4);
+   width = png_get_uint_31(png_ptr, buf);
+   height = png_get_uint_31(png_ptr, buf + 4);
    bit_depth = buf[8];
    color_type = buf[9];
    compression_type = buf[10];
    filter_type = buf[11];
    interlace_type = buf[12];
 
-   /* check for width and height valid values */
-   if (width == 0 || width > (png_uint_32)2147483647L || height == 0 ||
-        height > (png_uint_32)2147483647L)
-      png_error(png_ptr, "Invalid image size in IHDR");
-
-   /* check other values */
-   if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
-      bit_depth != 8 && bit_depth != 16)
-      png_error(png_ptr, "Invalid bit depth in IHDR");
-
-   if (color_type < 0 || color_type == 1 ||
-      color_type == 5 || color_type > 6)
-      png_error(png_ptr, "Invalid color type in IHDR");
-
-   if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 ||
-       ((color_type == PNG_COLOR_TYPE_RGB ||
-         color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
-         color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
-      png_error(png_ptr, "Invalid color type/bit depth combination in IHDR");
-
-   if (interlace_type >= PNG_INTERLACE_LAST)
-      png_error(png_ptr, "Unknown interlace method in IHDR");
-
-   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
-      png_error(png_ptr, "Unknown compression method in IHDR");
-
-   if (filter_type != PNG_FILTER_TYPE_BASE)
-      png_error(png_ptr, "Unknown filter method in IHDR");
-
    /* set internal variables */
    png_ptr->width = width;
    png_ptr->height = height;
    png_ptr->bit_depth = (png_byte)bit_depth;
    png_ptr->interlaced = (png_byte)interlace_type;
    png_ptr->color_type = (png_byte)color_type;
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+   png_ptr->filter_type = (png_byte)filter_type;
+#endif
+   png_ptr->compression_type = (png_byte)compression_type;
 
    /* find number of channels */
    switch (png_ptr->color_type)
@@ -227,21 +406,23 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    /* set up other useful info */
    png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
    png_ptr->channels);
-   png_ptr->rowbytes = ((png_ptr->width *
-      (png_uint_32)png_ptr->pixel_depth + 7) >> 3);
+   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
    png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth);
    png_debug1(3,"channels = %d\n", png_ptr->channels);
-   png_debug1(3,"rowbytes = %d\n", png_ptr->rowbytes);
+   png_debug1(3,"rowbytes = %lu\n", png_ptr->rowbytes);
    png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
       color_type, interlace_type, compression_type, filter_type);
 }
 
 /* read and check the palette */
-void
+void /* PRIVATE */
 png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   png_colorp palette;
+   png_color palette[PNG_MAX_PALETTE_LENGTH];
    int num, i;
+#ifndef PNG_NO_POINTER_INDEXING
+   png_colorp pal_ptr;
+#endif
 
    png_debug(1, "in png_handle_PLTE\n");
 
@@ -258,20 +439,13 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    png_ptr->mode |= PNG_HAVE_PLTE;
 
-#if defined (PNG_READ_tRNS_SUPPORTED)
-   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
    {
-      if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
-      {
-         if (png_ptr->num_trans > png_ptr->num_palette)
-         {
-            png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
-            png_ptr->num_trans = png_ptr->num_palette;
-         }
-      }
+      png_warning(png_ptr,
+        "Ignoring PLTE chunk in grayscale PNG");
+      png_crc_finish(png_ptr, length);
+      return;
    }
-#endif
-
 #if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
    if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
    {
@@ -280,7 +454,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #endif
 
-   if (length % 3)
+   if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
    {
       if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
       {
@@ -295,8 +469,18 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 
    num = (int)length / 3;
-   palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color));
-   png_ptr->flags |= PNG_FLAG_FREE_PALETTE;
+
+#ifndef PNG_NO_POINTER_INDEXING
+   for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+   {
+      png_byte buf[3];
+
+      png_crc_read(png_ptr, buf, 3);
+      pal_ptr->red = buf[0];
+      pal_ptr->green = buf[1];
+      pal_ptr->blue = buf[2];
+   }
+#else
    for (i = 0; i < num; i++)
    {
       png_byte buf[3];
@@ -307,6 +491,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       palette[i].green = buf[1];
       palette[i].blue = buf[2];
    }
+#endif
 
    /* If we actually NEED the PLTE chunk (ie for a paletted image), we do
       whatever the normal CRC configuration tells us.  However, if we
@@ -334,8 +519,6 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
          else
          {
             png_chunk_warning(png_ptr, "CRC error");
-            png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE;
-            png_zfree(png_ptr, palette);
             return;
          }
       }
@@ -346,12 +529,31 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       }
    }
 #endif
-   png_ptr->palette = palette;
-   png_ptr->num_palette = (png_uint_16)num;
+
    png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+#if defined(PNG_READ_tRNS_SUPPORTED)
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+      {
+         if (png_ptr->num_trans > (png_uint_16)num)
+         {
+            png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
+            png_ptr->num_trans = (png_uint_16)num;
+         }
+         if (info_ptr->num_trans > (png_uint_16)num)
+         {
+            png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
+            info_ptr->num_trans = (png_uint_16)num;
+         }
+      }
+   }
+#endif
+
 }
 
-void
+void /* PRIVATE */
 png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_debug(1, "in png_handle_IEND\n");
@@ -359,27 +561,27 @@ png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
    {
       png_error(png_ptr, "No image in file");
-
-      /* to quiet compiler warnings about unused info_ptr */
-      if (info_ptr == NULL)
-         return;
    }
 
-   png_ptr->mode |= PNG_AFTER_IDAT | PNG_HAVE_IEND;
+   png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
 
    if (length != 0)
    {
       png_warning(png_ptr, "Incorrect IEND chunk length");
    }
    png_crc_finish(png_ptr, length);
+
+   info_ptr =info_ptr; /* quiet compiler warnings about unused info_ptr */
 }
 
 #if defined(PNG_READ_gAMA_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   png_uint_32 igamma;
+   png_fixed_point igamma;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    float file_gamma;
+#endif
    png_byte buf[4];
 
    png_debug(1, "in png_handle_gAMA\n");
@@ -396,7 +598,7 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       /* Should be an error, but we can cope with it */
       png_warning(png_ptr, "Out of place gAMA chunk");
 
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_gAMA
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
 #if defined(PNG_READ_sRGB_SUPPORTED)
       && !(info_ptr->valid & PNG_INFO_sRGB)
 #endif
@@ -418,34 +620,43 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (png_crc_finish(png_ptr, 0))
       return;
 
-   igamma = png_get_uint_32(buf);
+   igamma = (png_fixed_point)png_get_uint_32(buf);
    /* check for zero gamma */
    if (igamma == 0)
-      return;
+      {
+         png_warning(png_ptr,
+           "Ignoring gAMA chunk with gamma=0");
+         return;
+      }
 
 #if defined(PNG_READ_sRGB_SUPPORTED)
-   if (info_ptr->valid & PNG_INFO_sRGB)
-      if(igamma != (png_uint_32)45000L)
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+      if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
       {
          png_warning(png_ptr,
            "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
-         fprintf(stderr, "igamma = %lu\n", igamma);
+#ifndef PNG_NO_CONSOLE_IO
+         fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma);
 #endif
          return;
       }
 #endif /* PNG_READ_sRGB_SUPPORTED */
 
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    file_gamma = (float)igamma / (float)100000.0;
-#ifdef PNG_READ_GAMMA_SUPPORTED
-   png_ptr->gamma = file_gamma;
+#  ifdef PNG_READ_GAMMA_SUPPORTED
+     png_ptr->gamma = file_gamma;
+#  endif
+     png_set_gAMA(png_ptr, info_ptr, file_gamma);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
 #endif
-   png_set_gAMA(png_ptr, info_ptr, file_gamma);
 }
 #endif
 
 #if defined(PNG_READ_sBIT_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_size_t truelen;
@@ -468,7 +679,7 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       /* Should be an error, but we can cope with it */
       png_warning(png_ptr, "Out of place sBIT chunk");
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT)
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
    {
       png_warning(png_ptr, "Duplicate sBIT chunk");
       png_crc_finish(png_ptr, length);
@@ -480,7 +691,7 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    else
       truelen = (png_size_t)png_ptr->channels;
 
-   if (length != truelen)
+   if (length != truelen || length > 4)
    {
       png_warning(png_ptr, "Incorrect sBIT chunk length");
       png_crc_finish(png_ptr, length);
@@ -501,6 +712,9 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    else
    {
       png_ptr->sig_bit.gray = buf[0];
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[0];
+      png_ptr->sig_bit.blue = buf[0];
       png_ptr->sig_bit.alpha = buf[1];
    }
    png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
@@ -508,17 +722,22 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #endif
 
 #if defined(PNG_READ_cHRM_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_byte buf[4];
-   png_uint_32 val;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+   png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
+      int_y_green, int_x_blue, int_y_blue;
+
+   png_uint_32 uint_x, uint_y;
 
    png_debug(1, "in png_handle_cHRM\n");
 
    if (!(png_ptr->mode & PNG_HAVE_IHDR))
-      png_error(png_ptr, "Missing IHDR before sBIT");
+      png_error(png_ptr, "Missing IHDR before cHRM");
    else if (png_ptr->mode & PNG_HAVE_IDAT)
    {
       png_warning(png_ptr, "Invalid cHRM after IDAT");
@@ -529,7 +748,7 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       /* Should be an error, but we can cope with it */
       png_warning(png_ptr, "Missing PLTE before cHRM");
 
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
 #if defined(PNG_READ_sRGB_SUPPORTED)
       && !(info_ptr->valid & PNG_INFO_sRGB)
 #endif
@@ -548,105 +767,126 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   white_x = (float)val / (float)100000.0;
+   uint_x = png_get_uint_32(buf);
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   white_y = (float)val / (float)100000.0;
+   uint_y = png_get_uint_32(buf);
 
-   if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
-       white_x + white_y > 1.0)
+   if (uint_x > 80000L || uint_y > 80000L ||
+      uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM white point");
       png_crc_finish(png_ptr, 24);
       return;
    }
+   int_x_white = (png_fixed_point)uint_x;
+   int_y_white = (png_fixed_point)uint_y;
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   red_x = (float)val / (float)100000.0;
+   uint_x = png_get_uint_32(buf);
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   red_y = (float)val / (float)100000.0;
+   uint_y = png_get_uint_32(buf);
 
-   if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
-       red_x + red_y > 1.0)
+   if (uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM red point");
       png_crc_finish(png_ptr, 16);
       return;
    }
+   int_x_red = (png_fixed_point)uint_x;
+   int_y_red = (png_fixed_point)uint_y;
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   green_x = (float)val / (float)100000.0;
+   uint_x = png_get_uint_32(buf);
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   green_y = (float)val / (float)100000.0;
+   uint_y = png_get_uint_32(buf);
 
-   if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
-       green_x + green_y > 1.0)
+   if (uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM green point");
       png_crc_finish(png_ptr, 8);
       return;
    }
+   int_x_green = (png_fixed_point)uint_x;
+   int_y_green = (png_fixed_point)uint_y;
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   blue_x = (float)val / (float)100000.0;
+   uint_x = png_get_uint_32(buf);
 
    png_crc_read(png_ptr, buf, 4);
-   val = png_get_uint_32(buf);
-   blue_y = (float)val / (float)100000.0;
+   uint_y = png_get_uint_32(buf);
 
-   if (blue_x < (float)0 || blue_x > (float)0.8 || blue_y < (float)0 ||
-       blue_y > (float)0.8 || blue_x + blue_y > (float)1.0)
+   if (uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM blue point");
       png_crc_finish(png_ptr, 0);
       return;
    }
-
-   if (png_crc_finish(png_ptr, 0))
-      return;
+   int_x_blue = (png_fixed_point)uint_x;
+   int_y_blue = (png_fixed_point)uint_y;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   white_x = (float)int_x_white / (float)100000.0;
+   white_y = (float)int_y_white / (float)100000.0;
+   red_x   = (float)int_x_red   / (float)100000.0;
+   red_y   = (float)int_y_red   / (float)100000.0;
+   green_x = (float)int_x_green / (float)100000.0;
+   green_y = (float)int_y_green / (float)100000.0;
+   blue_x  = (float)int_x_blue  / (float)100000.0;
+   blue_y  = (float)int_y_blue  / (float)100000.0;
+#endif
 
 #if defined(PNG_READ_sRGB_SUPPORTED)
-   if (info_ptr->valid & PNG_INFO_sRGB)
+   if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
       {
-      if (fabs(white_x - (float).3127) > (float).001 ||
-          fabs(white_y - (float).3290) > (float).001 ||
-          fabs(  red_x - (float).6400) > (float).001 ||
-          fabs(  red_y - (float).3300) > (float).001 ||
-          fabs(green_x - (float).3000) > (float).001 ||
-          fabs(green_y - (float).6000) > (float).001 ||
-          fabs( blue_x - (float).1500) > (float).001 ||
-          fabs( blue_y - (float).0600) > (float).001)
+      if (PNG_OUT_OF_RANGE(int_x_white, 31270,  1000) ||
+          PNG_OUT_OF_RANGE(int_y_white, 32900,  1000) ||
+          PNG_OUT_OF_RANGE(int_x_red,   64000L, 1000) ||
+          PNG_OUT_OF_RANGE(int_y_red,   33000,  1000) ||
+          PNG_OUT_OF_RANGE(int_x_green, 30000,  1000) ||
+          PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) ||
+          PNG_OUT_OF_RANGE(int_x_blue,  15000,  1000) ||
+          PNG_OUT_OF_RANGE(int_y_blue,   6000,  1000))
          {
-
             png_warning(png_ptr,
               "Ignoring incorrect cHRM value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
+#ifdef PNG_FLOATING_POINT_SUPPORTED
             fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
                white_x, white_y, red_x, red_y);
             fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
                green_x, green_y, blue_x, blue_y);
+#else
+            fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
+               int_x_white, int_y_white, int_x_red, int_y_red);
+            fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
+               int_x_green, int_y_green, int_x_blue, int_y_blue);
 #endif
+#endif /* PNG_NO_CONSOLE_IO */
          }
+         png_crc_finish(png_ptr, 0);
          return;
       }
 #endif /* PNG_READ_sRGB_SUPPORTED */
 
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    png_set_cHRM(png_ptr, info_ptr,
       white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_set_cHRM_fixed(png_ptr, info_ptr,
+      int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
+      int_y_green, int_x_blue, int_y_blue);
+#endif
+   if (png_crc_finish(png_ptr, 0))
+      return;
 }
 #endif
 
 #if defined(PNG_READ_sRGB_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    int intent;
@@ -666,7 +906,7 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       /* Should be an error, but we can cope with it */
       png_warning(png_ptr, "Out of place sRGB chunk");
 
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB)
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
    {
       png_warning(png_ptr, "Duplicate sRGB chunk");
       png_crc_finish(png_ptr, length);
@@ -693,43 +933,323 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 
 #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
-   if ((info_ptr->valid & PNG_INFO_gAMA))
-      if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L)
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+   {
+   png_fixed_point igamma;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+      igamma=info_ptr->int_gamma;
+#else
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+      igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
+#  endif
+#endif
+      if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
       {
          png_warning(png_ptr,
            "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
-           fprintf(stderr,"gamma=%f\n",png_ptr->gamma);
+#ifndef PNG_NO_CONSOLE_IO
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+         fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma);
+#  else
+#    ifdef PNG_FLOATING_POINT_SUPPORTED
+         fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma);
+#    endif
+#  endif
 #endif
       }
+   }
 #endif /* PNG_READ_gAMA_SUPPORTED */
 
 #ifdef PNG_READ_cHRM_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_cHRM)
-      if (fabs(info_ptr->x_white - (float).3127) > (float).001 ||
-          fabs(info_ptr->y_white - (float).3290) > (float).001 ||
-          fabs(  info_ptr->x_red - (float).6400) > (float).001 ||
-          fabs(  info_ptr->y_red - (float).3300) > (float).001 ||
-          fabs(info_ptr->x_green - (float).3000) > (float).001 ||
-          fabs(info_ptr->y_green - (float).6000) > (float).001 ||
-          fabs( info_ptr->x_blue - (float).1500) > (float).001 ||
-          fabs( info_ptr->y_blue - (float).0600) > (float).001)
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+      if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_x_red,   64000L, 1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_y_red,   33000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_x_blue,  15000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->int_y_blue,   6000,  1000))
          {
             png_warning(png_ptr,
               "Ignoring incorrect cHRM value when sRGB is also present");
          }
+#endif /* PNG_FIXED_POINT_SUPPORTED */
 #endif /* PNG_READ_cHRM_SUPPORTED */
 
    png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
 }
 #endif /* PNG_READ_sRGB_SUPPORTED */
 
+#if defined(PNG_READ_iCCP_SUPPORTED)
+void /* PRIVATE */
+png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+   png_charp chunkdata;
+   png_byte compression_type;
+   png_bytep pC;
+   png_charp profile;
+   png_uint_32 skip = 0;
+   png_uint_32 profile_size, profile_length;
+   png_size_t slength, prefix_length, data_length;
+
+   png_debug(1, "in png_handle_iCCP\n");
+
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before iCCP");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid iCCP after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+      /* Should be an error, but we can cope with it */
+      png_warning(png_ptr, "Out of place iCCP chunk");
+
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+   {
+      png_warning(png_ptr, "Duplicate iCCP chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "iCCP chunk too large to fit in memory");
+      skip = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+
+   chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+   slength = (png_size_t)length;
+   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+
+   if (png_crc_finish(png_ptr, skip))
+   {
+      png_free(png_ptr, chunkdata);
+      return;
+   }
+
+   chunkdata[slength] = 0x00;
+
+   for (profile = chunkdata; *profile; profile++)
+      /* empty loop to find end of name */ ;
+
+   ++profile;
+
+   /* there should be at least one zero (the compression type byte)
+      following the separator, and we should be on it  */
+   if ( profile >= chunkdata + slength - 1)
+   {
+      png_free(png_ptr, chunkdata);
+      png_warning(png_ptr, "Malformed iCCP chunk");
+      return;
+   }
+
+   /* compression_type should always be zero */
+   compression_type = *profile++;
+   if (compression_type)
+   {
+      png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
+      compression_type=0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
+                                 wrote nonzero) */
+   }
+
+   prefix_length = profile - chunkdata;
+   chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata,
+                                    slength, prefix_length, &data_length);
+
+   profile_length = data_length - prefix_length;
+
+   if ( prefix_length > data_length || profile_length < 4)
+   {
+      png_free(png_ptr, chunkdata);
+      png_warning(png_ptr, "Profile size field missing from iCCP chunk");
+      return;
+   }
+
+   /* Check the profile_size recorded in the first 32 bits of the ICC profile */
+   pC = (png_bytep)(chunkdata+prefix_length);
+   profile_size = ((*(pC  ))<<24) |
+                  ((*(pC+1))<<16) |
+                  ((*(pC+2))<< 8) |
+                  ((*(pC+3))    );
+
+   if(profile_size < profile_length)
+      profile_length = profile_size;
+
+   if(profile_size > profile_length)
+   {
+      png_free(png_ptr, chunkdata);
+      png_warning(png_ptr, "Ignoring truncated iCCP profile.");
+      return;
+   }
+
+   png_set_iCCP(png_ptr, info_ptr, chunkdata, compression_type,
+                chunkdata + prefix_length, profile_length);
+   png_free(png_ptr, chunkdata);
+}
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#if defined(PNG_READ_sPLT_SUPPORTED)
+void /* PRIVATE */
+png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+   png_bytep chunkdata;
+   png_bytep entry_start;
+   png_sPLT_t new_palette;
+#ifdef PNG_NO_POINTER_INDEXING
+   png_sPLT_entryp pp;
+#endif
+   int data_length, entry_size, i;
+   png_uint_32 skip = 0;
+   png_size_t slength;
+
+   png_debug(1, "in png_handle_sPLT\n");
+
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before sPLT");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid sPLT after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "sPLT chunk too large to fit in memory");
+      skip = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+
+   chunkdata = (png_bytep)png_malloc(png_ptr, length + 1);
+   slength = (png_size_t)length;
+   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+
+   if (png_crc_finish(png_ptr, skip))
+   {
+      png_free(png_ptr, chunkdata);
+      return;
+   }
+
+   chunkdata[slength] = 0x00;
+
+   for (entry_start = chunkdata; *entry_start; entry_start++)
+      /* empty loop to find end of name */ ;
+   ++entry_start;
+
+   /* a sample depth should follow the separator, and we should be on it  */
+   if (entry_start > chunkdata + slength - 2)
+   {
+      png_free(png_ptr, chunkdata);
+      png_warning(png_ptr, "malformed sPLT chunk");
+      return;
+   }
+
+   new_palette.depth = *entry_start++;
+   entry_size = (new_palette.depth == 8 ? 6 : 10);
+   data_length = (slength - (entry_start - chunkdata));
+
+   /* integrity-check the data length */
+   if (data_length % entry_size)
+   {
+      png_free(png_ptr, chunkdata);
+      png_warning(png_ptr, "sPLT chunk has bad length");
+      return;
+   }
+
+   new_palette.nentries = (png_int_32) ( data_length / entry_size);
+   if ((png_uint_32) new_palette.nentries > (png_uint_32) (PNG_SIZE_MAX /
+       png_sizeof(png_sPLT_entry)))
+   {
+       png_warning(png_ptr, "sPLT chunk too long");
+       return;
+   }
+   new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+       png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+   if (new_palette.entries == NULL)
+   {
+       png_warning(png_ptr, "sPLT chunk requires too much memory");
+       return;
+   }
+
+#ifndef PNG_NO_POINTER_INDEXING
+   for (i = 0; i < new_palette.nentries; i++)
+   {
+      png_sPLT_entryp pp = new_palette.entries + i;
+
+      if (new_palette.depth == 8)
+      {
+          pp->red = *entry_start++;
+          pp->green = *entry_start++;
+          pp->blue = *entry_start++;
+          pp->alpha = *entry_start++;
+      }
+      else
+      {
+          pp->red   = png_get_uint_16(entry_start); entry_start += 2;
+          pp->green = png_get_uint_16(entry_start); entry_start += 2;
+          pp->blue  = png_get_uint_16(entry_start); entry_start += 2;
+          pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+      }
+      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+   }
+#else
+   pp = new_palette.entries;
+   for (i = 0; i < new_palette.nentries; i++)
+   {
+
+      if (new_palette.depth == 8)
+      {
+          pp[i].red   = *entry_start++;
+          pp[i].green = *entry_start++;
+          pp[i].blue  = *entry_start++;
+          pp[i].alpha = *entry_start++;
+      }
+      else
+      {
+          pp[i].red   = png_get_uint_16(entry_start); entry_start += 2;
+          pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+          pp[i].blue  = png_get_uint_16(entry_start); entry_start += 2;
+          pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+      }
+      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+   }
+#endif
+
+   /* discard all chunk data except the name and stash that */
+   new_palette.name = (png_charp)chunkdata;
+
+   png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+   png_free(png_ptr, chunkdata);
+   png_free(png_ptr, new_palette.entries);
+}
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
 #if defined(PNG_READ_tRNS_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
+   png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+   int bit_mask;
+
    png_debug(1, "in png_handle_tRNS\n");
 
+   /* For non-indexed color, mask off any bits in the tRNS value that
+    * exceed the bit depth.  Some creators were writing extra bits there.
+    * This is not needed for indexed color. */
+   bit_mask = (1 << png_ptr->bit_depth) - 1;
+
    if (!(png_ptr->mode & PNG_HAVE_IHDR))
       png_error(png_ptr, "Missing IHDR before tRNS");
    else if (png_ptr->mode & PNG_HAVE_IDAT)
@@ -738,31 +1258,27 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_crc_finish(png_ptr, length);
       return;
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
    {
       png_warning(png_ptr, "Duplicate tRNS chunk");
       png_crc_finish(png_ptr, length);
       return;
    }
 
-   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
    {
-      if (!(png_ptr->mode & PNG_HAVE_PLTE))
-      {
-         /* Should be an error, but we can cope with it */
-         png_warning(png_ptr, "Missing PLTE before tRNS");
-      }
-      else if (length > png_ptr->num_palette)
+      png_byte buf[2];
+
+      if (length != 2)
       {
          png_warning(png_ptr, "Incorrect tRNS chunk length");
          png_crc_finish(png_ptr, length);
          return;
       }
 
-      png_ptr->trans = (png_bytep)png_malloc(png_ptr, length);
-      png_ptr->flags |= PNG_FLAG_FREE_TRANS;
-      png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length);
-      png_ptr->num_trans = (png_uint_16)length;
+      png_crc_read(png_ptr, buf, 2);
+      png_ptr->num_trans = 1;
+      png_ptr->trans_values.gray = png_get_uint_16(buf) & bit_mask;
    }
    else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
    {
@@ -774,27 +1290,34 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
          png_crc_finish(png_ptr, length);
          return;
       }
-
       png_crc_read(png_ptr, buf, (png_size_t)length);
       png_ptr->num_trans = 1;
-      png_ptr->trans_values.red = png_get_uint_16(buf);
-      png_ptr->trans_values.green = png_get_uint_16(buf + 2);
-      png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
+      png_ptr->trans_values.red = png_get_uint_16(buf) & bit_mask;
+      png_ptr->trans_values.green = png_get_uint_16(buf + 2) & bit_mask;
+      png_ptr->trans_values.blue = png_get_uint_16(buf + 4) & bit_mask;
    }
-   else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+   else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
    {
-      png_byte buf[6];
-
-      if (length != 2)
+      if (!(png_ptr->mode & PNG_HAVE_PLTE))
+      {
+         /* Should be an error, but we can cope with it. */
+         png_warning(png_ptr, "Missing PLTE before tRNS");
+      }
+      if (length > (png_uint_32)png_ptr->num_palette ||
+          length > PNG_MAX_PALETTE_LENGTH)
       {
          png_warning(png_ptr, "Incorrect tRNS chunk length");
          png_crc_finish(png_ptr, length);
          return;
       }
-
-      png_crc_read(png_ptr, buf, 2);
-      png_ptr->num_trans = 1;
-      png_ptr->trans_values.gray = png_get_uint_16(buf);
+      if (length == 0)
+      {
+         png_warning(png_ptr, "Zero length tRNS chunk");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      png_crc_read(png_ptr, readbuf, (png_size_t)length);
+      png_ptr->num_trans = (png_uint_16)length;
    }
    else
    {
@@ -804,15 +1327,18 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 
    if (png_crc_finish(png_ptr, 0))
+   {
+      png_ptr->num_trans = 0;
       return;
+   }
 
-   png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans,
+   png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
       &(png_ptr->trans_values));
 }
 #endif
 
 #if defined(PNG_READ_bKGD_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_size_t truelen;
@@ -835,7 +1361,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_crc_finish(png_ptr, length);
       return;
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_bKGD)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
    {
       png_warning(png_ptr, "Duplicate bKGD chunk");
       png_crc_finish(png_ptr, length);
@@ -867,9 +1393,20 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
    {
       png_ptr->background.index = buf[0];
-      png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
-      png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
-      png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+      if(info_ptr->num_palette)
+      {
+          if(buf[0] > info_ptr->num_palette)
+          {
+             png_warning(png_ptr, "Incorrect bKGD chunk index value");
+             return;
+          }
+          png_ptr->background.red =
+             (png_uint_16)png_ptr->palette[buf[0]].red;
+          png_ptr->background.green =
+             (png_uint_16)png_ptr->palette[buf[0]].green;
+          png_ptr->background.blue =
+             (png_uint_16)png_ptr->palette[buf[0]].blue;
+      }
    }
    else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
    {
@@ -890,10 +1427,11 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #endif
 
 #if defined(PNG_READ_hIST_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   int num, i;
+   unsigned int num, i;
+   png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
 
    png_debug(1, "in png_handle_hIST\n");
 
@@ -911,41 +1449,39 @@ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_crc_finish(png_ptr, length);
       return;
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_hIST)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
    {
       png_warning(png_ptr, "Duplicate hIST chunk");
       png_crc_finish(png_ptr, length);
       return;
    }
 
-   if (length != (png_uint_32)(2 * png_ptr->num_palette))
+   num = length / 2 ;
+   if (num != (unsigned int) png_ptr->num_palette || num >
+      (unsigned int) PNG_MAX_PALETTE_LENGTH)
    {
       png_warning(png_ptr, "Incorrect hIST chunk length");
       png_crc_finish(png_ptr, length);
       return;
    }
 
-   num = (int)length / 2;
-   png_ptr->hist = (png_uint_16p)png_malloc(png_ptr,
-      (png_uint_32)(num * sizeof (png_uint_16)));
-   png_ptr->flags |= PNG_FLAG_FREE_HIST;
    for (i = 0; i < num; i++)
    {
       png_byte buf[2];
 
       png_crc_read(png_ptr, buf, 2);
-      png_ptr->hist[i] = png_get_uint_16(buf);
+      readbuf[i] = png_get_uint_16(buf);
    }
 
    if (png_crc_finish(png_ptr, 0))
       return;
 
-   png_set_hIST(png_ptr, info_ptr, png_ptr->hist);
+   png_set_hIST(png_ptr, info_ptr, readbuf);
 }
 #endif
 
 #if defined(PNG_READ_pHYs_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_byte buf[9];
@@ -955,16 +1491,16 @@ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    png_debug(1, "in png_handle_pHYs\n");
 
    if (!(png_ptr->mode & PNG_HAVE_IHDR))
-      png_error(png_ptr, "Missing IHDR before pHYS");
+      png_error(png_ptr, "Missing IHDR before pHYs");
    else if (png_ptr->mode & PNG_HAVE_IDAT)
    {
-      png_warning(png_ptr, "Invalid pHYS after IDAT");
+      png_warning(png_ptr, "Invalid pHYs after IDAT");
       png_crc_finish(png_ptr, length);
       return;
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
-      png_warning(png_ptr, "Duplicate pHYS chunk");
+      png_warning(png_ptr, "Duplicate pHYs chunk");
       png_crc_finish(png_ptr, length);
       return;
    }
@@ -988,11 +1524,11 @@ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #endif
 
 #if defined(PNG_READ_oFFs_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_byte buf[9];
-   png_uint_32 offset_x, offset_y;
+   png_int_32 offset_x, offset_y;
    int unit_type;
 
    png_debug(1, "in png_handle_oFFs\n");
@@ -1005,7 +1541,7 @@ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_crc_finish(png_ptr, length);
       return;
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_oFFs)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
    {
       png_warning(png_ptr, "Duplicate oFFs chunk");
       png_crc_finish(png_ptr, length);
@@ -1023,16 +1559,16 @@ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (png_crc_finish(png_ptr, 0))
       return;
 
-   offset_x = png_get_uint_32(buf);
-   offset_y = png_get_uint_32(buf + 4);
+   offset_x = png_get_int_32(buf);
+   offset_y = png_get_int_32(buf + 4);
    unit_type = buf[8];
    png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
 }
 #endif
 
 #if defined(PNG_READ_pCAL_SUPPORTED)
-/* read the pCAL chunk (png-scivis-19970203) */
-void
+/* read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
 png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_charp purpose;
@@ -1053,16 +1589,21 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_crc_finish(png_ptr, length);
       return;
    }
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
    {
       png_warning(png_ptr, "Duplicate pCAL chunk");
       png_crc_finish(png_ptr, length);
       return;
    }
 
-   png_debug1(2, "Allocating and reading pCAL chunk data (%d bytes)\n",
+   png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n",
       length + 1);
-   purpose = (png_charp)png_malloc(png_ptr, length + 1);
+   purpose = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (purpose == NULL)
+     {
+       png_warning(png_ptr, "No memory for pCAL purpose.");
+       return;
+     }
    slength = (png_size_t)length;
    png_crc_read(png_ptr, (png_bytep)purpose, slength);
 
@@ -1075,7 +1616,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    purpose[slength] = 0x00; /* null terminate the last string */
 
    png_debug(3, "Finding end of pCAL purpose string\n");
-   for (buf = purpose; *buf != '\0'; buf++)
+   for (buf = purpose; *buf; buf++)
       /* empty loop */ ;
 
    endptr = purpose + slength;
@@ -1113,42 +1654,176 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
    }
 
-   for (buf = units; *buf != 0x00; buf++)
+   for (buf = units; *buf; buf++)
       /* Empty loop to move past the units string. */ ;
 
    png_debug(3, "Allocating pCAL parameters array\n");
-   params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams
-      *sizeof(png_charp))) ;
+   params = (png_charpp)png_malloc_warn(png_ptr, (png_uint_32)(nparams
+      *png_sizeof(png_charp))) ;
+   if (params == NULL)
+     {
+       png_free(png_ptr, purpose);
+       png_warning(png_ptr, "No memory for pCAL params.");
+       return;
+     }
+
+   /* Get pointers to the start of each parameter string. */
+   for (i = 0; i < (int)nparams; i++)
+   {
+      buf++; /* Skip the null string terminator from previous parameter. */
+
+      png_debug1(3, "Reading pCAL parameter %d\n", i);
+      for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
+         /* Empty loop to move past each parameter string */ ;
+
+      /* Make sure we haven't run out of data yet */
+      if (buf > endptr)
+      {
+         png_warning(png_ptr, "Invalid pCAL data");
+         png_free(png_ptr, purpose);
+         png_free(png_ptr, params);
+         return;
+      }
+   }
+
+   png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams,
+      units, params);
+
+   png_free(png_ptr, purpose);
+   png_free(png_ptr, params);
+}
+#endif
+
+#if defined(PNG_READ_sCAL_SUPPORTED)
+/* read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_charp buffer, ep;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   double width, height;
+   png_charp vp;
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_charp swidth, sheight;
+#endif
+#endif
+   png_size_t slength;
+
+   png_debug(1, "in png_handle_sCAL\n");
+
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before sCAL");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid sCAL after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
+   {
+      png_warning(png_ptr, "Duplicate sCAL chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
+   png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n",
+      length + 1);
+   buffer = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (buffer == NULL)
+     {
+       png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+       return;
+     }
+   slength = (png_size_t)length;
+   png_crc_read(png_ptr, (png_bytep)buffer, slength);
+
+   if (png_crc_finish(png_ptr, 0))
+   {
+      png_free(png_ptr, buffer);
+      return;
+   }
+
+   buffer[slength] = 0x00; /* null terminate the last string */
+
+   ep = buffer + 1;        /* skip unit byte */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   width = png_strtod(png_ptr, ep, &vp);
+   if (*vp)
+   {
+       png_warning(png_ptr, "malformed width string in sCAL chunk");
+       return;
+   }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
+   if (swidth == NULL)
+     {
+       png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
+       return;
+     }
+   png_memcpy(swidth, ep, (png_size_t)png_strlen(ep));
+#endif
+#endif
+
+   for (ep = buffer; *ep; ep++)
+      /* empty loop */ ;
+   ep++;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   height = png_strtod(png_ptr, ep, &vp);
+   if (*vp)
+   {
+       png_warning(png_ptr, "malformed height string in sCAL chunk");
+       return;
+   }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
+   if (swidth == NULL)
+     {
+       png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
+       return;
+     }
+   png_memcpy(sheight, ep, (png_size_t)png_strlen(ep));
+#endif
+#endif
 
-   /* Get pointers to the start of each parameter string. */
-   for (i = 0; i < (int)nparams; i++)
+   if (buffer + slength < ep
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+      || width <= 0. || height <= 0.
+#endif
+      )
    {
-      buf++; /* Skip the null string terminator from previous parameter. */
-
-      png_debug1(3, "Reading pCAL parameter %d\n", i);
-      for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
-         /* Empty loop to move past each parameter string */ ;
-
-      /* Make sure we haven't run out of data yet */
-      if (buf > endptr)
-      {
-         png_warning(png_ptr, "Invalid pCAL data");
-         png_free(png_ptr, purpose);
-         png_free(png_ptr, params);
-         return;
-      }
+      png_warning(png_ptr, "Invalid sCAL data");
+      png_free(png_ptr, buffer);
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+      png_free(png_ptr, swidth);
+      png_free(png_ptr, sheight);
+#endif
+      return;
    }
 
-   png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams,
-      units, params);
 
-   png_free(png_ptr, purpose);
-   png_free(png_ptr, params);
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   png_set_sCAL(png_ptr, info_ptr, buffer[0], width, height);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_set_sCAL_s(png_ptr, info_ptr, buffer[0], swidth, sheight);
+#endif
+#endif
+
+   png_free(png_ptr, buffer);
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+   png_free(png_ptr, swidth);
+   png_free(png_ptr, sheight);
+#endif
 }
 #endif
 
 #if defined(PNG_READ_tIME_SUPPORTED)
-void
+void /* PRIVATE */
 png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_byte buf[7];
@@ -1158,7 +1833,7 @@ png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    if (!(png_ptr->mode & PNG_HAVE_IHDR))
       png_error(png_ptr, "Out of place tIME chunk");
-   else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME)
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
    {
       png_warning(png_ptr, "Duplicate tIME chunk");
       png_crc_finish(png_ptr, length);
@@ -1192,7 +1867,7 @@ png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
 #if defined(PNG_READ_tEXt_SUPPORTED)
 /* Note: this does not properly handle chunks that are > 64K under DOS */
-void
+void /* PRIVATE */
 png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_textp text_ptr;
@@ -1200,6 +1875,7 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    png_charp text;
    png_uint_32 skip = 0;
    png_size_t slength;
+   int ret;
 
    png_debug(1, "in png_handle_tEXt\n");
 
@@ -1218,7 +1894,12 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #endif
 
-   key = (png_charp)png_malloc(png_ptr, length + 1);
+   key = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (key == NULL)
+   {
+     png_warning(png_ptr, "No memory to process text chunk.");
+     return;
+   }
    slength = (png_size_t)length;
    png_crc_read(png_ptr, (png_bytep)key, slength);
 
@@ -1236,31 +1917,46 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (text != key + slength)
       text++;
 
-   text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
+   text_ptr = (png_textp)png_malloc_warn(png_ptr,
+      (png_uint_32)png_sizeof(png_text));
+   if (text_ptr == NULL)
+   {
+     png_warning(png_ptr, "Not enough memory to process text chunk.");
+     png_free(png_ptr, key);
+     return;
+   }
    text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
    text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+   text_ptr->lang = NULL;
+   text_ptr->lang_key = NULL;
+   text_ptr->itxt_length = 0;
+#endif
    text_ptr->text = text;
+   text_ptr->text_length = png_strlen(text);
 
-   png_set_text(png_ptr, info_ptr, text_ptr, 1);
+   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
 
+   png_free(png_ptr, key);
    png_free(png_ptr, text_ptr);
+   if (ret)
+     png_warning(png_ptr, "Insufficient memory to process text chunk.");
 }
 #endif
 
 #if defined(PNG_READ_zTXt_SUPPORTED)
 /* note: this does not correctly handle chunks that are > 64K under DOS */
-void
+void /* PRIVATE */
 png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   static char msg[] = "Error decoding zTXt chunk";
    png_textp text_ptr;
-   png_charp key;
+   png_charp chunkdata;
    png_charp text;
-   int comp_type = PNG_TEXT_COMPRESSION_NONE;
-   png_size_t slength;
+   int comp_type;
+   int ret;
+   png_size_t slength, prefix_len, data_len;
 
    png_debug(1, "in png_handle_zTXt\n");
-
    if (!(png_ptr->mode & PNG_HAVE_IHDR))
       png_error(png_ptr, "Missing IHDR before zTXt");
 
@@ -1278,172 +1974,277 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #endif
 
-   key = (png_charp)png_malloc(png_ptr, length + 1);
+   chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (chunkdata == NULL)
+   {
+     png_warning(png_ptr,"Out of memory processing zTXt chunk.");
+     return;
+   }
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)key, slength);
+   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
    if (png_crc_finish(png_ptr, 0))
    {
-      png_free(png_ptr, key);
+      png_free(png_ptr, chunkdata);
       return;
    }
 
-   key[slength] = 0x00;
+   chunkdata[slength] = 0x00;
 
-   for (text = key; *text; text++)
+   for (text = chunkdata; *text; text++)
       /* empty loop */ ;
 
-   /* zTXt must have some text after the keyword */
-   if (text == key + slength)
+   /* zTXt must have some text after the chunkdataword */
+   if (text == chunkdata + slength - 1)
    {
-      png_warning(png_ptr, "Zero length zTXt chunk");
+      png_warning(png_ptr, "Truncated zTXt chunk");
+      png_free(png_ptr, chunkdata);
+      return;
    }
-   else if ((comp_type = *(++text)) == PNG_TEXT_COMPRESSION_zTXt)
+   else
    {
-      png_size_t text_size, key_size;
-      text++;
+       comp_type = *(++text);
+       if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
+       {
+          png_warning(png_ptr, "Unknown compression type in zTXt chunk");
+          comp_type = PNG_TEXT_COMPRESSION_zTXt;
+       }
+       text++;        /* skip the compression_method byte */
+   }
+   prefix_len = text - chunkdata;
 
-      png_ptr->zstream.next_in = (png_bytep)text;
-      png_ptr->zstream.avail_in = (uInt)(length - (text - key));
-      png_ptr->zstream.next_out = png_ptr->zbuf;
-      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+   chunkdata = (png_charp)png_decompress_chunk(png_ptr, comp_type, chunkdata,
+                                    (png_size_t)length, prefix_len, &data_len);
 
-      key_size = (png_size_t)(text - key);
-      text_size = 0;
-      text = NULL;
+   text_ptr = (png_textp)png_malloc_warn(png_ptr,
+     (png_uint_32)png_sizeof(png_text));
+   if (text_ptr == NULL)
+   {
+     png_warning(png_ptr,"Not enough memory to process zTXt chunk.");
+     png_free(png_ptr, chunkdata);
+     return;
+   }
+   text_ptr->compression = comp_type;
+   text_ptr->key = chunkdata;
+#ifdef PNG_iTXt_SUPPORTED
+   text_ptr->lang = NULL;
+   text_ptr->lang_key = NULL;
+   text_ptr->itxt_length = 0;
+#endif
+   text_ptr->text = chunkdata + prefix_len;
+   text_ptr->text_length = data_len;
 
-      while (png_ptr->zstream.avail_in)
-      {
-         int ret;
+   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
 
-         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
-         if (ret != Z_OK && ret != Z_STREAM_END)
-         {
-            if (png_ptr->zstream.msg != NULL)
-               png_warning(png_ptr, png_ptr->zstream.msg);
-            else
-               png_warning(png_ptr, msg);
-            inflateReset(&png_ptr->zstream);
-            png_ptr->zstream.avail_in = 0;
+   png_free(png_ptr, text_ptr);
+   png_free(png_ptr, chunkdata);
+   if (ret)
+     png_error(png_ptr, "Insufficient memory to store zTXt chunk.");
+}
+#endif
 
-            if (text ==  NULL)
-            {
-               text_size = key_size + sizeof(msg) + 1;
-               text = (png_charp)png_malloc(png_ptr, (png_uint_32)text_size);
-               png_memcpy(text, key, key_size);
-            }
+#if defined(PNG_READ_iTXt_SUPPORTED)
+/* note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_textp text_ptr;
+   png_charp chunkdata;
+   png_charp key, lang, text, lang_key;
+   int comp_flag;
+   int comp_type = 0;
+   int ret;
+   png_size_t slength, prefix_len, data_len;
 
-            text[text_size - 1] = 0x00;
+   png_debug(1, "in png_handle_iTXt\n");
 
-            /* Copy what we can of the error message into the text chunk */
-            text_size = (png_size_t)(slength - (text - key) - 1);
-            text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
-            png_memcpy(text + key_size, msg, text_size + 1);
-            break;
-         }
-         if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
-         {
-            if (text == NULL)
-            {
-               text = (png_charp)png_malloc(png_ptr,
-                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
-                     + key_size + 1));
-               png_memcpy(text + key_size, png_ptr->zbuf,
-                  png_ptr->zbuf_size - png_ptr->zstream.avail_out);
-               png_memcpy(text, key, key_size);
-               text_size = key_size + png_ptr->zbuf_size -
-                  png_ptr->zstream.avail_out;
-               *(text + text_size) = 0x00;
-            }
-            else
-            {
-               png_charp tmp;
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before iTXt");
 
-               tmp = text;
-               text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size +
-                  png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
-               png_memcpy(text, tmp, text_size);
-               png_free(png_ptr, tmp);
-               png_memcpy(text + text_size, png_ptr->zbuf,
-                  (png_ptr->zbuf_size - png_ptr->zstream.avail_out));
-               text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
-               *(text + text_size) = 0x00;
-            }
-            if (ret != Z_STREAM_END)
-            {
-               png_ptr->zstream.next_out = png_ptr->zbuf;
-               png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-            }
-            else
-            {
-               break;
-            }
-         }
-      }
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+      png_ptr->mode |= PNG_AFTER_IDAT;
 
-      inflateReset(&png_ptr->zstream);
-      png_ptr->zstream.avail_in = 0;
+#ifdef PNG_MAX_MALLOC_64K
+   /* We will no doubt have problems with chunks even half this size, but
+      there is no hard and fast rule to tell us where to stop. */
+   if (length > (png_uint_32)65535L)
+   {
+     png_warning(png_ptr,"iTXt chunk too large to fit in memory");
+     png_crc_finish(png_ptr, length);
+     return;
+   }
+#endif
 
-      png_free(png_ptr, key);
-      key = text;
-      text += key_size;
+   chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (chunkdata == NULL)
+   {
+     png_warning(png_ptr, "No memory to process iTXt chunk.");
+     return;
    }
-   else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */
+   slength = (png_size_t)length;
+   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+   if (png_crc_finish(png_ptr, 0))
    {
-      png_size_t text_size;
-#if !defined(PNG_NO_STDIO)
-      char umsg[50];
+      png_free(png_ptr, chunkdata);
+      return;
+   }
 
-      sprintf(umsg, "Unknown zTXt compression type %d", comp_type);
-      png_warning(png_ptr, umsg);
-#else
-      png_warning(png_ptr, "Unknown zTXt compression type");
-#endif
+   chunkdata[slength] = 0x00;
+
+   for (lang = chunkdata; *lang; lang++)
+      /* empty loop */ ;
+   lang++;        /* skip NUL separator */
+
+   /* iTXt must have a language tag (possibly empty), two compression bytes,
+      translated keyword (possibly empty), and possibly some text after the
+      keyword */
+
+   if (lang >= chunkdata + slength - 3)
+   {
+      png_warning(png_ptr, "Truncated iTXt chunk");
+      png_free(png_ptr, chunkdata);
+      return;
+   }
+   else
+   {
+       comp_flag = *lang++;
+       comp_type = *lang++;
+   }
+
+   for (lang_key = lang; *lang_key; lang_key++)
+      /* empty loop */ ;
+   lang_key++;        /* skip NUL separator */
 
-      /* Copy what we can of the error message into the text chunk */
-      text_size = (png_size_t)(slength - (text - key) - 1);
-      text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
-      png_memcpy(text, msg, text_size + 1);
+   for (text = lang_key; *text; text++)
+      /* empty loop */ ;
+   text++;        /* skip NUL separator */
+   if (text >= chunkdata + slength)
+   {
+      png_warning(png_ptr, "Malformed iTXt chunk");
+      png_free(png_ptr, chunkdata);
+      return;
    }
 
-   text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
-   text_ptr->compression = comp_type;
-   text_ptr->key = key;
-   text_ptr->text = text;
+   prefix_len = text - chunkdata;
+
+   key=chunkdata;
+   if (comp_flag)
+       chunkdata = png_decompress_chunk(png_ptr, comp_type, chunkdata,
+          (size_t)length, prefix_len, &data_len);
+   else
+       data_len=png_strlen(chunkdata + prefix_len);
+   text_ptr = (png_textp)png_malloc_warn(png_ptr,
+      (png_uint_32)png_sizeof(png_text));
+   if (text_ptr == NULL)
+   {
+     png_warning(png_ptr,"Not enough memory to process iTXt chunk.");
+     png_free(png_ptr, chunkdata);
+     return;
+   }
+   text_ptr->compression = (int)comp_flag + 1;
+   text_ptr->lang_key = chunkdata+(lang_key-key);
+   text_ptr->lang = chunkdata+(lang-key);
+   text_ptr->itxt_length = data_len;
+   text_ptr->text_length = 0;
+   text_ptr->key = chunkdata;
+   text_ptr->text = chunkdata + prefix_len;
 
-   png_set_text(png_ptr, info_ptr, text_ptr, 1);
+   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
 
    png_free(png_ptr, text_ptr);
+   png_free(png_ptr, chunkdata);
+   if (ret)
+     png_error(png_ptr, "Insufficient memory to store iTXt chunk.");
 }
 #endif
 
 /* This function is called when we haven't found a handler for a
    chunk.  If there isn't a problem with the chunk itself (ie bad
-   chunk name, CRC, or a critical chunk), the chunk is silently ignored. */
-void
+   chunk name, CRC, or a critical chunk), the chunk is silently ignored
+   -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
+   case it will be saved away to be written out later. */
+void /* PRIVATE */
 png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
+   png_uint_32 skip = 0;
+
    png_debug(1, "in png_handle_unknown\n");
 
-   /* In the future we can have code here that calls user-supplied
-    * callback functions for unknown chunks before they are ignored or
-    * cause an error.
-    */
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+#ifdef PNG_USE_LOCAL_ARRAYS
+      PNG_CONST PNG_IDAT;
+#endif
+      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))  /* not an IDAT */
+         png_ptr->mode |= PNG_AFTER_IDAT;
+   }
+
    png_check_chunk_name(png_ptr, png_ptr->chunk_name);
 
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
-      png_chunk_error(png_ptr, "unknown critical chunk");
-
-      /* to quiet compiler warnings about unused info_ptr */
-      if (info_ptr == NULL)
-         return;
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+      if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+           PNG_HANDLE_CHUNK_ALWAYS
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+           && png_ptr->read_user_chunk_fn == NULL
+#endif
+        )
+#endif
+          png_chunk_error(png_ptr, "unknown critical chunk");
    }
 
-   if (png_ptr->mode & PNG_HAVE_IDAT)
-      png_ptr->mode |= PNG_AFTER_IDAT;
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+   if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) ||
+       (png_ptr->read_user_chunk_fn != NULL))
+   {
+#ifdef PNG_MAX_MALLOC_64K
+       if (length > (png_uint_32)65535L)
+       {
+           png_warning(png_ptr, "unknown chunk too large to fit in memory");
+           skip = length - (png_uint_32)65535L;
+           length = (png_uint_32)65535L;
+       }
+#endif
+       png_strncpy((png_charp)png_ptr->unknown_chunk.name,
+	 (png_charp)png_ptr->chunk_name,
+         png_sizeof((png_charp)png_ptr->chunk_name));
+       png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+       png_ptr->unknown_chunk.size = (png_size_t)length;
+       png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+       if(png_ptr->read_user_chunk_fn != NULL)
+       {
+          /* callback to user unknown chunk handler */
+          int ret;
+          ret = (*(png_ptr->read_user_chunk_fn))
+            (png_ptr, &png_ptr->unknown_chunk);
+          if (ret < 0)
+             png_chunk_error(png_ptr, "error in user chunk");
+          if (ret == 0)
+          {
+             if (!(png_ptr->chunk_name[0] & 0x20))
+                if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+                     PNG_HANDLE_CHUNK_ALWAYS)
+                   png_chunk_error(png_ptr, "unknown critical chunk");
+             png_set_unknown_chunks(png_ptr, info_ptr,
+               &png_ptr->unknown_chunk, 1);
+          }
+       }
+#else
+       png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+#endif
+       png_free(png_ptr, png_ptr->unknown_chunk.data);
+       png_ptr->unknown_chunk.data = NULL;
+   }
+   else
+#endif
+      skip = length;
 
-   png_crc_finish(png_ptr, length);
+   png_crc_finish(png_ptr, skip);
 
+#if !defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+   info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
+#endif
 }
 
 /* This function is called to verify that a chunk name is valid.
@@ -1452,9 +2253,9 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    functions to handle unknown critical chunks after we check that
    the chunk name itself is valid. */
 
-#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97))
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
 
-void
+void /* PRIVATE */
 png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
 {
    png_debug(1, "in png_check_chunk_name\n");
@@ -1465,26 +2266,25 @@ png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
    }
 }
 
-/* Combines the row recently read in with the previous row.
-   This routine takes care of alpha and transparency if requested.
+/* Combines the row recently read in with the existing pixels in the
+   row.  This routine takes care of alpha and transparency if requested.
    This routine also handles the two methods of progressive display
    of interlaced images, depending on the mask value.
    The mask value describes which pixels are to be combined with
    the row.  The pattern always repeats every 8 pixels, so just 8
-   bits are needed.  A one indicates the pixels is to be combined,
+   bits are needed.  A one indicates the pixel is to be combined,
    a zero indicates the pixel is to be skipped.  This is in addition
    to any alpha or transparency value associated with the pixel.  If
    you want all pixels to be combined, pass 0xff (255) in mask.  */
-void
-png_combine_row(png_structp png_ptr, png_bytep row,
-   int mask)
+
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep row, int mask)
 {
    png_debug(1,"in png_combine_row\n");
    if (mask == 0xff)
    {
       png_memcpy(row, png_ptr->row_buf + 1,
-         (png_size_t)((png_ptr->width *
-         png_ptr->row_info.pixel_depth + 7) >> 3));
+         PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
    }
    else
    {
@@ -1492,16 +2292,14 @@ png_combine_row(png_structp png_ptr, png_bytep row,
       {
          case 1:
          {
-            png_bytep sp;
-            png_bytep dp;
+            png_bytep sp = png_ptr->row_buf + 1;
+            png_bytep dp = row;
             int s_inc, s_start, s_end;
-            int m;
+            int m = 0x80;
             int shift;
             png_uint_32 i;
+            png_uint_32 row_width = png_ptr->width;
 
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
             if (png_ptr->transformations & PNG_PACKSWAP)
             {
@@ -1519,13 +2317,13 @@ png_combine_row(png_structp png_ptr, png_bytep row,
 
             shift = s_start;
 
-            for (i = 0; i < png_ptr->width; i++)
+            for (i = 0; i < row_width; i++)
             {
                if (m & mask)
                {
                   int value;
 
-                  value = (*sp >> shift) & 0x1;
+                  value = (*sp >> shift) & 0x01;
                   *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
                   *dp |= (png_byte)(value << shift);
                }
@@ -1548,17 +2346,15 @@ png_combine_row(png_structp png_ptr, png_bytep row,
          }
          case 2:
          {
-            png_bytep sp;
-            png_bytep dp;
+            png_bytep sp = png_ptr->row_buf + 1;
+            png_bytep dp = row;
             int s_start, s_end, s_inc;
-            int m;
+            int m = 0x80;
             int shift;
             png_uint_32 i;
+            png_uint_32 row_width = png_ptr->width;
             int value;
 
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
             if (png_ptr->transformations & PNG_PACKSWAP)
             {
@@ -1576,11 +2372,11 @@ png_combine_row(png_structp png_ptr, png_bytep row,
 
             shift = s_start;
 
-            for (i = 0; i < png_ptr->width; i++)
+            for (i = 0; i < row_width; i++)
             {
                if (m & mask)
                {
-                  value = (*sp >> shift) & 0x3;
+                  value = (*sp >> shift) & 0x03;
                   *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
                   *dp |= (png_byte)(value << shift);
                }
@@ -1602,17 +2398,15 @@ png_combine_row(png_structp png_ptr, png_bytep row,
          }
          case 4:
          {
-            png_bytep sp;
-            png_bytep dp;
+            png_bytep sp = png_ptr->row_buf + 1;
+            png_bytep dp = row;
             int s_start, s_end, s_inc;
-            int m;
+            int m = 0x80;
             int shift;
             png_uint_32 i;
+            png_uint_32 row_width = png_ptr->width;
             int value;
 
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
             if (png_ptr->transformations & PNG_PACKSWAP)
             {
@@ -1629,7 +2423,7 @@ png_combine_row(png_structp png_ptr, png_bytep row,
             }
             shift = s_start;
 
-            for (i = 0; i < png_ptr->width; i++)
+            for (i = 0; i < row_width; i++)
             {
                if (m & mask)
                {
@@ -1655,18 +2449,15 @@ png_combine_row(png_structp png_ptr, png_bytep row,
          }
          default:
          {
-            png_bytep sp;
-            png_bytep dp;
-            png_size_t pixel_bytes;
+            png_bytep sp = png_ptr->row_buf + 1;
+            png_bytep dp = row;
+            png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
             png_uint_32 i;
-            png_byte m;
+            png_uint_32 row_width = png_ptr->width;
+            png_byte m = 0x80;
 
-            pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
 
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
-            for (i = 0; i < png_ptr->width; i++)
+            for (i = 0; i < row_width; i++)
             {
                if (m & mask)
                {
@@ -1687,11 +2478,24 @@ png_combine_row(png_structp png_ptr, png_bytep row,
    }
 }
 
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
-void
-png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* OLD pre-1.0.9 interface:
+void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
    png_uint_32 transformations)
+ */
+void /* PRIVATE */
+png_do_read_interlace(png_structp png_ptr)
 {
+   png_row_infop row_info = &(png_ptr->row_info);
+   png_bytep row = png_ptr->row_buf + 1;
+   int pass = png_ptr->pass;
+   png_uint_32 transformations = png_ptr->transformations;
+#ifdef PNG_USE_LOCAL_ARRAYS
+   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* offset to next interlace block */
+   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+#endif
+
    png_debug(1,"in png_do_read_interlace\n");
    if (row != NULL && row_info != NULL)
    {
@@ -1703,20 +2507,20 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
       {
          case 1:
          {
-            png_bytep sp, dp;
+            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+            png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
             int sshift, dshift;
             int s_start, s_end, s_inc;
+            int jstop = png_pass_inc[pass];
             png_byte v;
             png_uint_32 i;
             int j;
 
-            sp = row + (png_size_t)((row_info->width - 1) >> 3);
-            dp = row + (png_size_t)((final_width - 1) >> 3);
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
             if (transformations & PNG_PACKSWAP)
             {
-                sshift = (int)((row_info->width + 7) & 7);
-                dshift = (int)((final_width + 7) & 7);
+                sshift = (int)((row_info->width + 7) & 0x07);
+                dshift = (int)((final_width + 7) & 0x07);
                 s_start = 7;
                 s_end = 0;
                 s_inc = -1;
@@ -1724,17 +2528,17 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
             else
 #endif
             {
-                sshift = 7 - (int)((row_info->width + 7) & 7);
-                dshift = 7 - (int)((final_width + 7) & 7);
+                sshift = 7 - (int)((row_info->width + 7) & 0x07);
+                dshift = 7 - (int)((final_width + 7) & 0x07);
                 s_start = 0;
                 s_end = 7;
                 s_inc = 1;
             }
 
-            for (i = row_info->width; i; i--)
+            for (i = 0; i < row_info->width; i++)
             {
-               v = (png_byte)((*sp >> sshift) & 0x1);
-               for (j = 0; j < png_pass_inc[pass]; j++)
+               v = (png_byte)((*sp >> sshift) & 0x01);
+               for (j = 0; j < jstop; j++)
                {
                   *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
                   *dp |= (png_byte)(v << dshift);
@@ -1758,18 +2562,18 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
          }
          case 2:
          {
-            png_bytep sp, dp;
+            png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+            png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
             int sshift, dshift;
             int s_start, s_end, s_inc;
+            int jstop = png_pass_inc[pass];
             png_uint_32 i;
 
-            sp = row + (png_uint_32)((row_info->width - 1) >> 2);
-            dp = row + (png_uint_32)((final_width - 1) >> 2);
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
             if (transformations & PNG_PACKSWAP)
             {
-               sshift = (int)(((row_info->width + 3) & 3) << 1);
-               dshift = (int)(((final_width + 3) & 3) << 1);
+               sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+               dshift = (int)(((final_width + 3) & 0x03) << 1);
                s_start = 6;
                s_end = 0;
                s_inc = -2;
@@ -1777,20 +2581,20 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
             else
 #endif
             {
-               sshift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
-               dshift = (int)((3 - ((final_width + 3) & 3)) << 1);
+               sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+               dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
                s_start = 0;
                s_end = 6;
                s_inc = 2;
             }
 
-            for (i = row_info->width; i; i--)
+            for (i = 0; i < row_info->width; i++)
             {
                png_byte v;
                int j;
 
-               v = (png_byte)((*sp >> sshift) & 0x3);
-               for (j = 0; j < png_pass_inc[pass]; j++)
+               v = (png_byte)((*sp >> sshift) & 0x03);
+               for (j = 0; j < jstop; j++)
                {
                   *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
                   *dp |= (png_byte)(v << dshift);
@@ -1814,18 +2618,18 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
          }
          case 4:
          {
-            png_bytep sp, dp;
+            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+            png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
             int sshift, dshift;
             int s_start, s_end, s_inc;
             png_uint_32 i;
+            int jstop = png_pass_inc[pass];
 
-            sp = row + (png_size_t)((row_info->width - 1) >> 1);
-            dp = row + (png_size_t)((final_width - 1) >> 1);
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
             if (transformations & PNG_PACKSWAP)
             {
-               sshift = (int)(((row_info->width + 1) & 1) << 2);
-               dshift = (int)(((final_width + 1) & 1) << 2);
+               sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+               dshift = (int)(((final_width + 1) & 0x01) << 2);
                s_start = 4;
                s_end = 0;
                s_inc = -4;
@@ -1833,20 +2637,19 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
             else
 #endif
             {
-               sshift = (int)((1 - ((row_info->width + 1) & 1)) << 2);
-               dshift = (int)((1 - ((final_width + 1) & 1)) << 2);
+               sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+               dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
                s_start = 0;
                s_end = 4;
                s_inc = 4;
             }
 
-            for (i = row_info->width; i; i--)
+            for (i = 0; i < row_info->width; i++)
             {
-               png_byte v;
+               png_byte v = (png_byte)((*sp >> sshift) & 0xf);
                int j;
 
-               v = (png_byte)((*sp >> sshift) & 0xf);
-               for (j = 0; j < png_pass_inc[pass]; j++)
+               for (j = 0; j < jstop; j++)
                {
                   *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
                   *dp |= (png_byte)(v << dshift);
@@ -1870,21 +2673,20 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
          }
          default:
          {
-            png_bytep sp, dp;
-            png_uint_32 i;
-            png_size_t pixel_bytes;
+            png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+            png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
+            png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
 
-            pixel_bytes = (row_info->pixel_depth >> 3);
+            int jstop = png_pass_inc[pass];
+            png_uint_32 i;
 
-            sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
-            dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
-            for (i = row_info->width; i; i--)
+            for (i = 0; i < row_info->width; i++)
             {
                png_byte v[8];
                int j;
 
                png_memcpy(v, sp, pixel_bytes);
-               for (j = 0; j < png_pass_inc[pass]; j++)
+               for (j = 0; j < jstop; j++)
                {
                   png_memcpy(dp, v, pixel_bytes);
                   dp -= pixel_bytes;
@@ -1895,20 +2697,20 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
          }
       }
       row_info->width = final_width;
-      row_info->rowbytes = ((final_width *
-         (png_uint_32)row_info->pixel_depth + 7) >> 3);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,final_width);
    }
-}
+#if !defined(PNG_READ_PACKSWAP_SUPPORTED)
+   transformations = transformations; /* silence compiler warning */
 #endif
+}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
 
-void
+void /* PRIVATE */
 png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
    png_bytep prev_row, int filter)
 {
    png_debug(1, "in png_read_filter_row\n");
-   png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
-
-
+   png_debug2(2,"row = %lu, filter = %d\n", png_ptr->row_number, filter);
    switch (filter)
    {
       case PNG_FILTER_VALUE_NONE:
@@ -1916,104 +2718,135 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
       case PNG_FILTER_VALUE_SUB:
       {
          png_uint_32 i;
-         int bpp;
-         png_bytep rp;
-         png_bytep lp;
+         png_uint_32 istop = row_info->rowbytes;
+         png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+         png_bytep rp = row + bpp;
+         png_bytep lp = row;
 
-         bpp = (row_info->pixel_depth + 7) / 8;
-         for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
-            i < row_info->rowbytes; i++, rp++, lp++)
+         for (i = bpp; i < istop; i++)
          {
-            *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
+            *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
+            rp++;
          }
          break;
       }
       case PNG_FILTER_VALUE_UP:
       {
          png_uint_32 i;
-         png_bytep rp;
-         png_bytep pp;
+         png_uint_32 istop = row_info->rowbytes;
+         png_bytep rp = row;
+         png_bytep pp = prev_row;
 
-         for (i = 0, rp = row, pp = prev_row;
-            i < row_info->rowbytes; i++, rp++, pp++)
+         for (i = 0; i < istop; i++)
          {
-            *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
+            *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+            rp++;
          }
          break;
       }
       case PNG_FILTER_VALUE_AVG:
       {
          png_uint_32 i;
-         int bpp;
-         png_bytep rp;
-         png_bytep pp;
-         png_bytep lp;
-
-         bpp = (row_info->pixel_depth + 7) / 8;
-         for (i = 0, rp = row, pp = prev_row;
-            i < (png_uint_32)bpp; i++, rp++, pp++)
+         png_bytep rp = row;
+         png_bytep pp = prev_row;
+         png_bytep lp = row;
+         png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+         png_uint_32 istop = row_info->rowbytes - bpp;
+
+         for (i = 0; i < bpp; i++)
          {
             *rp = (png_byte)(((int)(*rp) +
-               ((int)(*pp) / 2)) & 0xff);
+               ((int)(*pp++) / 2 )) & 0xff);
+            rp++;
          }
-         for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++)
+
+         for (i = 0; i < istop; i++)
          {
             *rp = (png_byte)(((int)(*rp) +
-               (int)(*pp + *lp) / 2) & 0xff);
+               (int)(*pp++ + *lp++) / 2 ) & 0xff);
+            rp++;
          }
          break;
       }
       case PNG_FILTER_VALUE_PAETH:
       {
-         int bpp;
          png_uint_32 i;
-         png_bytep rp;
-         png_bytep pp;
-         png_bytep lp;
-         png_bytep cp;
-
-         bpp = (row_info->pixel_depth + 7) / 8;
-         for (i = 0, rp = row, pp = prev_row,
-            lp = row - bpp, cp = prev_row - bpp;
-            i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++)
+         png_bytep rp = row;
+         png_bytep pp = prev_row;
+         png_bytep lp = row;
+         png_bytep cp = prev_row;
+         png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+         png_uint_32 istop=row_info->rowbytes - bpp;
+
+         for (i = 0; i < bpp; i++)
+         {
+            *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+            rp++;
+         }
+
+         for (i = 0; i < istop; i++)   /* use leftover rp,pp */
          {
             int a, b, c, pa, pb, pc, p;
 
-            b = *pp;
-            if (i >= (png_uint_32)bpp)
-            {
-               c = *cp;
-               a = *lp;
-            }
-            else
-            {
-               a = c = 0;
-            }
-            p = a + b - c;
-            pa = abs(p - a);
-            pb = abs(p - b);
-            pc = abs(p - c);
-
-            if (pa <= pb && pa <= pc)
-               p = a;
-            else if (pb <= pc)
-               p = b;
-            else
-               p = c;
+            a = *lp++;
+            b = *pp++;
+            c = *cp++;
+
+            p = b - c;
+            pc = a - c;
+
+#ifdef PNG_USE_ABS
+            pa = abs(p);
+            pb = abs(pc);
+            pc = abs(p + pc);
+#else
+            pa = p < 0 ? -p : p;
+            pb = pc < 0 ? -pc : pc;
+            pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+            /*
+               if (pa <= pb && pa <= pc)
+                  p = a;
+               else if (pb <= pc)
+                  p = b;
+               else
+                  p = c;
+             */
+
+            p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
 
             *rp = (png_byte)(((int)(*rp) + p) & 0xff);
+            rp++;
          }
          break;
       }
       default:
-         png_error(png_ptr, "Bad adaptive filter type");
+         png_warning(png_ptr, "Ignoring bad adaptive filter type");
+         *row=0;
          break;
    }
 }
 
-void
+void /* PRIVATE */
 png_read_finish_row(png_structp png_ptr)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* start of interlace block */
+   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* offset to next interlace block */
+   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* start of interlace block in the y direction */
+   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* offset to next interlace block in the y direction */
+   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
    png_debug(1, "in png_read_finish_row\n");
    png_ptr->row_number++;
    if (png_ptr->row_number < png_ptr->num_rows)
@@ -2022,7 +2855,8 @@ png_read_finish_row(png_structp png_ptr)
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
-      png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      png_memset_check(png_ptr, png_ptr->prev_row, 0,
+         png_ptr->rowbytes + 1);
       do
       {
          png_ptr->pass++;
@@ -2032,8 +2866,9 @@ png_read_finish_row(png_structp png_ptr)
             png_pass_inc[png_ptr->pass] - 1 -
             png_pass_start[png_ptr->pass]) /
             png_pass_inc[png_ptr->pass];
-            png_ptr->irowbytes = ((png_ptr->iwidth *
-               (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
+
+         png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
+            png_ptr->iwidth) + 1;
 
          if (!(png_ptr->transformations & PNG_INTERLACE))
          {
@@ -2044,7 +2879,7 @@ png_read_finish_row(png_structp png_ptr)
             if (!(png_ptr->num_rows))
                continue;
          }
-         if (png_ptr->transformations & PNG_INTERLACE)
+         else  /* if (png_ptr->transformations & PNG_INTERLACE) */
             break;
       } while (png_ptr->iwidth == 0);
 
@@ -2054,6 +2889,9 @@ png_read_finish_row(png_structp png_ptr)
 
    if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
    {
+#ifdef PNG_USE_LOCAL_ARRAYS
+      PNG_CONST PNG_IDAT;
+#endif
       char extra;
       int ret;
 
@@ -2070,11 +2908,10 @@ png_read_finish_row(png_structp png_ptr)
                png_crc_finish(png_ptr, 0);
 
                png_read_data(png_ptr, chunk_length, 4);
-               png_ptr->idat_size = png_get_uint_32(chunk_length);
-
+               png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
                png_reset_crc(png_ptr);
                png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-               if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+               if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
                   png_error(png_ptr, "Not enough image data");
 
             }
@@ -2090,7 +2927,7 @@ png_read_finish_row(png_structp png_ptr)
          {
             if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
                png_ptr->idat_size)
-               png_error(png_ptr, "Extra compressed data");
+               png_warning(png_ptr, "Extra compressed data");
             png_ptr->mode |= PNG_AFTER_IDAT;
             png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
             break;
@@ -2100,25 +2937,46 @@ png_read_finish_row(png_structp png_ptr)
                       "Decompression Error");
 
          if (!(png_ptr->zstream.avail_out))
-            png_error(png_ptr, "Extra compressed data");
+         {
+            png_warning(png_ptr, "Extra compressed data.");
+            png_ptr->mode |= PNG_AFTER_IDAT;
+            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+            break;
+         }
 
       }
       png_ptr->zstream.avail_out = 0;
    }
 
    if (png_ptr->idat_size || png_ptr->zstream.avail_in)
-      png_error(png_ptr, "Extra compression data");
+      png_warning(png_ptr, "Extra compression data");
 
    inflateReset(&png_ptr->zstream);
 
    png_ptr->mode |= PNG_AFTER_IDAT;
 }
 
-void
+void /* PRIVATE */
 png_read_start_row(png_structp png_ptr)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* start of interlace block */
+   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* offset to next interlace block */
+   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* start of interlace block in the y direction */
+   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* offset to next interlace block in the y direction */
+   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
    int max_pixel_depth;
-   png_uint_32 rowbytes;
+   png_uint_32 row_bytes;
 
    png_debug(1, "in png_read_start_row\n");
    png_ptr->zstream.avail_in = 0;
@@ -2136,10 +2994,10 @@ png_read_start_row(png_structp png_ptr)
          png_pass_start[png_ptr->pass]) /
          png_pass_inc[png_ptr->pass];
 
-         rowbytes = ((png_ptr->iwidth *
-            (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
-         png_ptr->irowbytes = (png_size_t)rowbytes;
-         if((png_uint_32)png_ptr->irowbytes != rowbytes)
+         row_bytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->iwidth) + 1;
+
+         png_ptr->irowbytes = (png_size_t)row_bytes;
+         if((png_uint_32)png_ptr->irowbytes != row_bytes)
             png_error(png_ptr, "Rowbytes overflow in png_read_start_row");
    }
    else
@@ -2186,60 +3044,102 @@ png_read_start_row(png_structp png_ptr)
 #if defined(PNG_READ_FILLER_SUPPORTED)
    if (png_ptr->transformations & (PNG_FILLER))
    {
-      if (max_pixel_depth < 32)
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
          max_pixel_depth = 32;
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (max_pixel_depth <= 8)
+            max_pixel_depth = 16;
+         else
+            max_pixel_depth = 32;
+      }
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+      {
+         if (max_pixel_depth <= 32)
+            max_pixel_depth = 32;
+         else
+            max_pixel_depth = 64;
+      }
    }
 #endif
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
    if (png_ptr->transformations & PNG_GRAY_TO_RGB)
    {
-      if ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
-         png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      if (
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+        (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#if defined(PNG_READ_FILLER_SUPPORTED)
+        (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+        png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
       {
          if (max_pixel_depth <= 16)
             max_pixel_depth = 32;
-         else if (max_pixel_depth <= 32)
+         else
             max_pixel_depth = 64;
       }
       else
       {
          if (max_pixel_depth <= 8)
-            max_pixel_depth = 24;
-         else if (max_pixel_depth <= 16)
+           {
+             if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+               max_pixel_depth = 32;
+             else
+               max_pixel_depth = 24;
+           }
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            max_pixel_depth = 64;
+         else
             max_pixel_depth = 48;
       }
    }
 #endif
 
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+   if(png_ptr->transformations & PNG_USER_TRANSFORM)
+     {
+       int user_pixel_depth=png_ptr->user_transform_depth*
+         png_ptr->user_transform_channels;
+       if(user_pixel_depth > max_pixel_depth)
+         max_pixel_depth=user_pixel_depth;
+     }
+#endif
+
    /* align the width on the next larger 8 pixels.  Mainly used
       for interlacing */
-   rowbytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+   row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
    /* calculate the maximum bytes needed, adding a byte and a pixel
-      for safety sake */
-   rowbytes = ((rowbytes * (png_uint_32)max_pixel_depth + 7) >> 3) +
+      for safety's sake */
+   row_bytes = PNG_ROWBYTES(max_pixel_depth,row_bytes) +
       1 + ((max_pixel_depth + 7) >> 3);
 #ifdef PNG_MAX_MALLOC_64K
-   if (rowbytes > (png_uint_32)65536L)
+   if (row_bytes > (png_uint_32)65536L)
       png_error(png_ptr, "This image requires a row greater than 64KB");
 #endif
-   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, rowbytes);
+   png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64);
+   png_ptr->row_buf = png_ptr->big_row_buf+32;
 
 #ifdef PNG_MAX_MALLOC_64K
    if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
       png_error(png_ptr, "This image requires a row greater than 64KB");
 #endif
+   if ((png_uint_32)png_ptr->rowbytes > (png_uint_32)(PNG_SIZE_MAX - 1))
+      png_error(png_ptr, "Row has too many bytes to allocate in memory.");
    png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
       png_ptr->rowbytes + 1));
 
    png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
-   png_debug1(3, "width = %d,\n", png_ptr->width);
-   png_debug1(3, "height = %d,\n", png_ptr->height);
-   png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth);
-   png_debug1(3, "num_rows = %d\n", png_ptr->num_rows);
-   png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes);
-   png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes);
+   png_debug1(3, "width = %lu,\n", png_ptr->width);
+   png_debug1(3, "height = %lu,\n", png_ptr->height);
+   png_debug1(3, "iwidth = %lu,\n", png_ptr->iwidth);
+   png_debug1(3, "num_rows = %lu\n", png_ptr->num_rows);
+   png_debug1(3, "rowbytes = %lu,\n", png_ptr->rowbytes);
+   png_debug1(3, "irowbytes = %lu,\n", png_ptr->irowbytes);
 
    png_ptr->flags |= PNG_FLAG_ROW_INIT;
 }
+#endif /* PNG_READ_SUPPORTED */