jdk/src/java.desktop/share/native/libsplashscreen/libpng/pngtest.c
changeset 25859 3317bb8137f4
parent 10576 db3409425573
child 29913 95258013e132
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/native/libsplashscreen/libpng/pngtest.c	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,1825 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* pngtest.c - a simple test program to test libpng
+ *
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file and, per its terms, should not be removed:
+ *
+ * Last changed in libpng 1.5.4 [July 7, 2011]
+ * Copyright (c) 1998-2011 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 code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This program reads in a PNG image, writes it out again, and then
+ * compares the two files.  If the files are identical, this shows that
+ * the basic chunk handling, filtering, and (de)compression code is working
+ * properly.  It does not currently test all of the transforms, although
+ * it probably should.
+ *
+ * The program will report "FAIL" in certain legitimate cases:
+ * 1) when the compression level or filter selection method is changed.
+ * 2) when the maximum IDAT size (PNG_ZBUF_SIZE in pngconf.h) is not 8192.
+ * 3) unknown unsafe-to-copy ancillary chunks or unknown critical chunks
+ *    exist in the input file.
+ * 4) others not listed here...
+ * In these cases, it is best to check with another tool such as "pngcheck"
+ * to see what the differences between the two files are.
+ *
+ * If a filename is given on the command-line, then this file is used
+ * for the input, rather than the default "pngtest.png".  This allows
+ * testing a wide variety of files easily.  You can also test a number
+ * of files at once by typing "pngtest -m file1.png file2.png ..."
+ */
+
+#define _POSIX_SOURCE 1
+
+#include "zlib.h"
+#include "png.h"
+/* Copied from pngpriv.h but only used in error messages below. */
+#ifndef PNG_ZBUF_SIZE
+#  define PNG_ZBUF_SIZE 8192
+#endif
+#  include <stdio.h>
+#  include <stdlib.h>
+#  include <string.h>
+#  define FCLOSE(file) fclose(file)
+
+#ifndef PNG_STDIO_SUPPORTED
+typedef FILE                * png_FILE_p;
+#endif
+
+/* Makes pngtest verbose so we can find problems. */
+#ifndef PNG_DEBUG
+#  define PNG_DEBUG 0
+#endif
+
+#if PNG_DEBUG > 1
+#  define pngtest_debug(m)        ((void)fprintf(stderr, m "\n"))
+#  define pngtest_debug1(m,p1)    ((void)fprintf(stderr, m "\n", p1))
+#  define pngtest_debug2(m,p1,p2) ((void)fprintf(stderr, m "\n", p1, p2))
+#else
+#  define pngtest_debug(m)        ((void)0)
+#  define pngtest_debug1(m,p1)    ((void)0)
+#  define pngtest_debug2(m,p1,p2) ((void)0)
+#endif
+
+#if !PNG_DEBUG
+#  define SINGLE_ROWBUF_ALLOC  /* Makes buffer overruns easier to nail */
+#endif
+
+/* The code uses memcmp and memcpy on large objects (typically row pointers) so
+ * it is necessary to do soemthing special on certain architectures, note that
+ * the actual support for this was effectively removed in 1.4, so only the
+ * memory remains in this program:
+ */
+#define CVT_PTR(ptr)         (ptr)
+#define CVT_PTR_NOCHECK(ptr) (ptr)
+#define png_memcmp  memcmp
+#define png_memcpy  memcpy
+#define png_memset  memset
+
+/* Turn on CPU timing
+#define PNGTEST_TIMING
+*/
+
+#ifndef PNG_FLOATING_POINT_SUPPORTED
+#undef PNGTEST_TIMING
+#endif
+
+#ifdef PNGTEST_TIMING
+static float t_start, t_stop, t_decode, t_encode, t_misc;
+#include <time.h>
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+#define PNG_tIME_STRING_LENGTH 29
+static int tIME_chunk_present = 0;
+static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
+#endif
+
+static int verbose = 0;
+
+int test_one_file PNGARG((PNG_CONST char *inname, PNG_CONST char *outname));
+
+#ifdef __TURBOC__
+#include <mem.h>
+#endif
+
+/* Defined so I can write to a file on gui/windowing platforms */
+/*  #define STDERR stderr  */
+#define STDERR stdout   /* For DOS */
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) png_ptr->jmpbuf
+#endif
+
+/* Example of using row callbacks to make a simple progress meter */
+static int status_pass = 1;
+static int status_dots_requested = 0;
+static int status_dots = 1;
+
+void PNGCBAPI
+read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass);
+void PNGCBAPI
+read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
+{
+   if (png_ptr == NULL || row_number > PNG_UINT_31_MAX)
+      return;
+
+   if (status_pass != pass)
+   {
+      fprintf(stdout, "\n Pass %d: ", pass);
+      status_pass = pass;
+      status_dots = 31;
+   }
+
+   status_dots--;
+
+   if (status_dots == 0)
+   {
+      fprintf(stdout, "\n         ");
+      status_dots=30;
+   }
+
+   fprintf(stdout, "r");
+}
+
+void PNGCBAPI
+write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass);
+void PNGCBAPI
+write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
+{
+   if (png_ptr == NULL || row_number > PNG_UINT_31_MAX || pass > 7)
+      return;
+
+   fprintf(stdout, "w");
+}
+
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+/* Example of using user transform callback (we don't transform anything,
+ * but merely examine the row filters.  We set this to 256 rather than
+ * 5 in case illegal filter values are present.)
+ */
+static png_uint_32 filters_used[256];
+void PNGCBAPI
+count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data);
+void PNGCBAPI
+count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+   if (png_ptr != NULL && row_info != NULL)
+      ++filters_used[*(data - 1)];
+}
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+/* Example of using user transform callback (we don't transform anything,
+ * but merely count the zero samples)
+ */
+
+static png_uint_32 zero_samples;
+
+void PNGCBAPI
+count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data);
+void PNGCBAPI
+count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+   png_bytep dp = data;
+   if (png_ptr == NULL)
+      return;
+
+   /* Contents of row_info:
+    *  png_uint_32 width      width of row
+    *  png_uint_32 rowbytes   number of bytes in row
+    *  png_byte color_type    color type of pixels
+    *  png_byte bit_depth     bit depth of samples
+    *  png_byte channels      number of channels (1-4)
+    *  png_byte pixel_depth   bits per pixel (depth*channels)
+    */
+
+    /* Counts the number of zero samples (or zero pixels if color_type is 3 */
+
+    if (row_info->color_type == 0 || row_info->color_type == 3)
+    {
+       int pos = 0;
+       png_uint_32 n, nstop;
+
+       for (n = 0, nstop=row_info->width; n<nstop; n++)
+       {
+          if (row_info->bit_depth == 1)
+          {
+             if (((*dp << pos++ ) & 0x80) == 0)
+                zero_samples++;
+
+             if (pos == 8)
+             {
+                pos = 0;
+                dp++;
+             }
+          }
+
+          if (row_info->bit_depth == 2)
+          {
+             if (((*dp << (pos+=2)) & 0xc0) == 0)
+                zero_samples++;
+
+             if (pos == 8)
+             {
+                pos = 0;
+                dp++;
+             }
+          }
+
+          if (row_info->bit_depth == 4)
+          {
+             if (((*dp << (pos+=4)) & 0xf0) == 0)
+                zero_samples++;
+
+             if (pos == 8)
+             {
+                pos = 0;
+                dp++;
+             }
+          }
+
+          if (row_info->bit_depth == 8)
+             if (*dp++ == 0)
+                zero_samples++;
+
+          if (row_info->bit_depth == 16)
+          {
+             if ((*dp | *(dp+1)) == 0)
+                zero_samples++;
+             dp+=2;
+          }
+       }
+    }
+    else /* Other color types */
+    {
+       png_uint_32 n, nstop;
+       int channel;
+       int color_channels = row_info->channels;
+       if (row_info->color_type > 3)color_channels--;
+
+       for (n = 0, nstop=row_info->width; n<nstop; n++)
+       {
+          for (channel = 0; channel < color_channels; channel++)
+          {
+             if (row_info->bit_depth == 8)
+                if (*dp++ == 0)
+                   zero_samples++;
+
+             if (row_info->bit_depth == 16)
+             {
+                if ((*dp | *(dp+1)) == 0)
+                   zero_samples++;
+
+                dp+=2;
+             }
+          }
+          if (row_info->color_type > 3)
+          {
+             dp++;
+             if (row_info->bit_depth == 16)
+                dp++;
+          }
+       }
+    }
+}
+#endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */
+
+static int wrote_question = 0;
+
+#ifndef PNG_STDIO_SUPPORTED
+/* START of code to validate stdio-free compilation */
+/* These copies of the default read/write functions come from pngrio.c and
+ * pngwio.c.  They allow "don't include stdio" testing of the library.
+ * This is the function that does the actual reading of data.  If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+
+#ifdef PNG_IO_STATE_SUPPORTED
+void
+pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
+   png_uint_32 io_op);
+void
+pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
+   png_uint_32 io_op)
+{
+   png_uint_32 io_state = png_get_io_state(png_ptr);
+   int err = 0;
+
+   /* Check if the current operation (reading / writing) is as expected. */
+   if ((io_state & PNG_IO_MASK_OP) != io_op)
+      png_error(png_ptr, "Incorrect operation in I/O state");
+
+   /* Check if the buffer size specific to the current location
+    * (file signature / header / data / crc) is as expected.
+    */
+   switch (io_state & PNG_IO_MASK_LOC)
+   {
+   case PNG_IO_SIGNATURE:
+      if (data_length > 8)
+         err = 1;
+      break;
+   case PNG_IO_CHUNK_HDR:
+      if (data_length != 8)
+         err = 1;
+      break;
+   case PNG_IO_CHUNK_DATA:
+      break;  /* no restrictions here */
+   case PNG_IO_CHUNK_CRC:
+      if (data_length != 4)
+         err = 1;
+      break;
+   default:
+      err = 1;  /* uninitialized */
+   }
+   if (err)
+      png_error(png_ptr, "Bad I/O state or buffer size");
+}
+#endif
+
+#ifndef USE_FAR_KEYWORD
+static void PNGCBAPI
+pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check = 0;
+   png_voidp io_ptr;
+
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   io_ptr = png_get_io_ptr(png_ptr);
+   if (io_ptr != NULL)
+   {
+      check = fread(data, 1, length, (png_FILE_p)io_ptr);
+   }
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Read Error");
+   }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_READING);
+#endif
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+
+static void PNGCBAPI
+pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   png_byte *n_data;
+   png_FILE_p io_ptr;
+
+   /* Check if data really is near. If so, use usual code. */
+   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_get_io_ptr(png_ptr));
+   if ((png_bytep)n_data == data)
+   {
+      check = fread(n_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t read, remaining, err;
+      check = 0;
+      remaining = length;
+
+      do
+      {
+         read = MIN(NEAR_BUF_SIZE, remaining);
+         err = fread(buf, 1, 1, io_ptr);
+         png_memcpy(data, buf, read); /* Copy far buffer to near buffer */
+         if (err != read)
+            break;
+         else
+            check += err;
+         data += read;
+         remaining -= read;
+      }
+      while (remaining != 0);
+   }
+
+   if (check != length)
+      png_error(png_ptr, "Read Error");
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_READING);
+#endif
+}
+#endif /* USE_FAR_KEYWORD */
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+static void PNGCBAPI
+pngtest_flush(png_structp png_ptr)
+{
+   /* Do nothing; fflush() is said to be just a waste of energy. */
+   PNG_UNUSED(png_ptr)   /* Stifle compiler warning */
+}
+#endif
+
+/* This is the function that does the actual writing of data.  If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+#ifndef USE_FAR_KEYWORD
+static void PNGCBAPI
+pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   check = fwrite(data, 1, length, (png_FILE_p)png_get_io_ptr(png_ptr));
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
+#endif
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+
+static void PNGCBAPI
+pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
+   png_FILE_p io_ptr;
+
+   /* Check if data really is near. If so, use usual code. */
+   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_get_io_ptr(png_ptr));
+
+   if ((png_bytep)near_data == data)
+   {
+      check = fwrite(near_data, 1, length, io_ptr);
+   }
+
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t written, remaining, err;
+      check = 0;
+      remaining = length;
+
+      do
+      {
+         written = MIN(NEAR_BUF_SIZE, remaining);
+         png_memcpy(buf, data, written); /* Copy far buffer to near buffer */
+         err = fwrite(buf, 1, written, io_ptr);
+         if (err != written)
+            break;
+         else
+            check += err;
+         data += written;
+         remaining -= written;
+      }
+      while (remaining != 0);
+   }
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
+#endif
+}
+#endif /* USE_FAR_KEYWORD */
+
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void PNGCBAPI
+pngtest_warning(png_structp png_ptr, png_const_charp message)
+{
+   PNG_CONST char *name = "UNKNOWN (ERROR!)";
+   char *test;
+   test = png_get_error_ptr(png_ptr);
+
+   if (test == NULL)
+     fprintf(STDERR, "%s: libpng warning: %s\n", name, message);
+
+   else
+     fprintf(STDERR, "%s: libpng warning: %s\n", test, message);
+}
+
+/* This is the default error handling function.  Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static void PNGCBAPI
+pngtest_error(png_structp png_ptr, png_const_charp message)
+{
+   pngtest_warning(png_ptr, message);
+   /* We can return because png_error calls the default handler, which is
+    * actually OK in this case.
+    */
+}
+#endif /* !PNG_STDIO_SUPPORTED */
+/* END of code to validate stdio-free compilation */
+
+/* START of code to validate memory allocation and deallocation */
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information.  zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ *
+ * This piece of code can be compiled to validate max 64K allocations
+ * by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K.
+ */
+typedef struct memory_information
+{
+   png_alloc_size_t          size;
+   png_voidp                 pointer;
+   struct memory_information FAR *next;
+} memory_information;
+typedef memory_information FAR *memory_infop;
+
+static memory_infop pinformation = NULL;
+static int current_allocation = 0;
+static int maximum_allocation = 0;
+static int total_allocation = 0;
+static int num_allocations = 0;
+
+png_voidp PNGCBAPI png_debug_malloc PNGARG((png_structp png_ptr,
+    png_alloc_size_t size));
+void PNGCBAPI png_debug_free PNGARG((png_structp png_ptr, png_voidp ptr));
+
+png_voidp
+PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
+{
+
+   /* png_malloc has already tested for NULL; png_create_struct calls
+    * png_debug_malloc directly, with png_ptr == NULL which is OK
+    */
+
+   if (size == 0)
+      return (NULL);
+
+   /* This calls the library allocator twice, once to get the requested
+      buffer and once to get a new free list entry. */
+   {
+      /* Disable malloc_fn and free_fn */
+      memory_infop pinfo;
+      png_set_mem_fn(png_ptr, NULL, NULL, NULL);
+      pinfo = (memory_infop)png_malloc(png_ptr,
+         png_sizeof(*pinfo));
+      pinfo->size = size;
+      current_allocation += size;
+      total_allocation += size;
+      num_allocations ++;
+
+      if (current_allocation > maximum_allocation)
+         maximum_allocation = current_allocation;
+
+      pinfo->pointer = png_malloc(png_ptr, size);
+      /* Restore malloc_fn and free_fn */
+
+      png_set_mem_fn(png_ptr,
+          NULL, png_debug_malloc, png_debug_free);
+
+      if (size != 0 && pinfo->pointer == NULL)
+      {
+         current_allocation -= size;
+         total_allocation -= size;
+         png_error(png_ptr,
+           "out of memory in pngtest->png_debug_malloc");
+      }
+
+      pinfo->next = pinformation;
+      pinformation = pinfo;
+      /* Make sure the caller isn't assuming zeroed memory. */
+      png_memset(pinfo->pointer, 0xdd, pinfo->size);
+
+      if (verbose)
+         printf("png_malloc %lu bytes at %p\n", (unsigned long)size,
+            pinfo->pointer);
+
+      return (png_voidp)(pinfo->pointer);
+   }
+}
+
+/* Free a pointer.  It is removed from the list at the same time. */
+void PNGCBAPI
+png_debug_free(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL)
+      fprintf(STDERR, "NULL pointer to png_debug_free.\n");
+
+   if (ptr == 0)
+   {
+#if 0 /* This happens all the time. */
+      fprintf(STDERR, "WARNING: freeing NULL pointer\n");
+#endif
+      return;
+   }
+
+   /* Unlink the element from the list. */
+   {
+      memory_infop FAR *ppinfo = &pinformation;
+
+      for (;;)
+      {
+         memory_infop pinfo = *ppinfo;
+
+         if (pinfo->pointer == ptr)
+         {
+            *ppinfo = pinfo->next;
+            current_allocation -= pinfo->size;
+            if (current_allocation < 0)
+               fprintf(STDERR, "Duplicate free of memory\n");
+            /* We must free the list element too, but first kill
+               the memory that is to be freed. */
+            png_memset(ptr, 0x55, pinfo->size);
+            png_free_default(png_ptr, pinfo);
+            pinfo = NULL;
+            break;
+         }
+
+         if (pinfo->next == NULL)
+         {
+            fprintf(STDERR, "Pointer %x not found\n", (unsigned int)ptr);
+            break;
+         }
+
+         ppinfo = &pinfo->next;
+      }
+   }
+
+   /* Finally free the data. */
+   if (verbose)
+      printf("Freeing %p\n", ptr);
+
+   png_free_default(png_ptr, ptr);
+   ptr = NULL;
+}
+#endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */
+/* END of code to test memory allocation/deallocation */
+
+
+/* Demonstration of user chunk support of the sTER and vpAg chunks */
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+
+/* (sTER is a public chunk not yet known by libpng.  vpAg is a private
+chunk used in ImageMagick to store "virtual page" size).  */
+
+static png_uint_32 user_chunk_data[4];
+
+    /* 0: sTER mode + 1
+     * 1: vpAg width
+     * 2: vpAg height
+     * 3: vpAg units
+     */
+
+static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
+   png_unknown_chunkp chunk)
+{
+   png_uint_32
+     *my_user_chunk_data;
+
+   /* Return one of the following:
+    *    return (-n);  chunk had an error
+    *    return (0);  did not recognize
+    *    return (n);  success
+    *
+    * The unknown chunk structure contains the chunk data:
+    * png_byte name[5];
+    * png_byte *data;
+    * png_size_t size;
+    *
+    * Note that libpng has already taken care of the CRC handling.
+    */
+
+   if (chunk->name[0] == 115 && chunk->name[1] ==  84 &&     /* s  T */
+       chunk->name[2] ==  69 && chunk->name[3] ==  82)       /* E  R */
+      {
+         /* Found sTER chunk */
+         if (chunk->size != 1)
+            return (-1); /* Error return */
+
+         if (chunk->data[0] != 0 && chunk->data[0] != 1)
+            return (-1);  /* Invalid mode */
+
+         my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
+         my_user_chunk_data[0]=chunk->data[0]+1;
+         return (1);
+      }
+
+   if (chunk->name[0] != 118 || chunk->name[1] != 112 ||    /* v  p */
+       chunk->name[2] !=  65 || chunk->name[3] != 103)      /* A  g */
+      return (0); /* Did not recognize */
+
+   /* Found ImageMagick vpAg chunk */
+
+   if (chunk->size != 9)
+      return (-1); /* Error return */
+
+   my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
+
+   my_user_chunk_data[1]=png_get_uint_31(png_ptr, chunk->data);
+   my_user_chunk_data[2]=png_get_uint_31(png_ptr, chunk->data + 4);
+   my_user_chunk_data[3]=(png_uint_32)chunk->data[8];
+
+   return (1);
+
+}
+#endif
+/* END of code to demonstrate user chunk support */
+
+/* Test one file */
+int
+test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
+{
+   static png_FILE_p fpin;
+   static png_FILE_p fpout;  /* "static" prevents setjmp corruption */
+   png_structp read_ptr;
+   png_infop read_info_ptr, end_info_ptr;
+#ifdef PNG_WRITE_SUPPORTED
+   png_structp write_ptr;
+   png_infop write_info_ptr;
+   png_infop write_end_info_ptr;
+#else
+   png_structp write_ptr = NULL;
+   png_infop write_info_ptr = NULL;
+   png_infop write_end_info_ptr = NULL;
+#endif
+   png_bytep row_buf;
+   png_uint_32 y;
+   png_uint_32 width, height;
+   int num_pass, pass;
+   int bit_depth, color_type;
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+   jmp_buf tmp_jmpbuf;
+#endif
+#endif
+
+   char inbuf[256], outbuf[256];
+
+   row_buf = NULL;
+
+   if ((fpin = fopen(inname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find input file %s\n", inname);
+      return (1);
+   }
+
+   if ((fpout = fopen(outname, "wb")) == NULL)
+   {
+      fprintf(STDERR, "Could not open output file %s\n", outname);
+      FCLOSE(fpin);
+      return (1);
+   }
+
+   pngtest_debug("Allocating read and write structures");
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+   read_ptr =
+      png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+#else
+   read_ptr =
+      png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+#endif
+#ifndef PNG_STDIO_SUPPORTED
+   png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error,
+       pngtest_warning);
+#endif
+
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+   user_chunk_data[0] = 0;
+   user_chunk_data[1] = 0;
+   user_chunk_data[2] = 0;
+   user_chunk_data[3] = 0;
+   png_set_read_user_chunk_fn(read_ptr, user_chunk_data,
+     read_user_chunk_callback);
+
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+   write_ptr =
+      png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+#else
+   write_ptr =
+      png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+#endif
+#ifndef PNG_STDIO_SUPPORTED
+   png_set_error_fn(write_ptr, (png_voidp)inname, pngtest_error,
+       pngtest_warning);
+#endif
+#endif
+   pngtest_debug("Allocating read_info, write_info and end_info structures");
+   read_info_ptr = png_create_info_struct(read_ptr);
+   end_info_ptr = png_create_info_struct(read_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+   write_info_ptr = png_create_info_struct(write_ptr);
+   write_end_info_ptr = png_create_info_struct(write_ptr);
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+   pngtest_debug("Setting jmpbuf for read struct");
+#ifdef USE_FAR_KEYWORD
+   if (setjmp(tmp_jmpbuf))
+#else
+   if (setjmp(png_jmpbuf(read_ptr)))
+#endif
+   {
+      fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname);
+      png_free(read_ptr, row_buf);
+      row_buf = NULL;
+      png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+      png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+      FCLOSE(fpin);
+      FCLOSE(fpout);
+      return (1);
+   }
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(png_jmpbuf(read_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("Setting jmpbuf for write struct");
+#ifdef USE_FAR_KEYWORD
+
+   if (setjmp(tmp_jmpbuf))
+#else
+   if (setjmp(png_jmpbuf(write_ptr)))
+#endif
+   {
+      fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname);
+      png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+      png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+      FCLOSE(fpin);
+      FCLOSE(fpout);
+      return (1);
+   }
+
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(png_jmpbuf(write_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+#endif
+#endif
+#endif
+
+   pngtest_debug("Initializing input and output streams");
+#ifdef PNG_STDIO_SUPPORTED
+   png_init_io(read_ptr, fpin);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_init_io(write_ptr, fpout);
+#  endif
+#else
+   png_set_read_fn(read_ptr, (png_voidp)fpin, pngtest_read_data);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_set_write_fn(write_ptr, (png_voidp)fpout,  pngtest_write_data,
+#    ifdef PNG_WRITE_FLUSH_SUPPORTED
+      pngtest_flush);
+#    else
+      NULL);
+#    endif
+#  endif
+#endif
+
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
+    * This is here just to make pngtest replicate the results from libpng
+    * versions prior to 1.5.4, and to test this new API.
+    */
+   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
+#endif
+
+   if (status_dots_requested == 1)
+   {
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_write_status_fn(write_ptr, write_row_callback);
+#endif
+      png_set_read_status_fn(read_ptr, read_row_callback);
+   }
+
+   else
+   {
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_write_status_fn(write_ptr, NULL);
+#endif
+      png_set_read_status_fn(read_ptr, NULL);
+   }
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   {
+      int i;
+
+      for (i = 0; i<256; i++)
+         filters_used[i] = 0;
+
+      png_set_read_user_transform_fn(read_ptr, count_filters);
+   }
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   zero_samples = 0;
+   png_set_write_user_transform_fn(write_ptr, count_zero_samples);
+#endif
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#  ifndef PNG_HANDLE_CHUNK_ALWAYS
+#    define PNG_HANDLE_CHUNK_ALWAYS       3
+#  endif
+   png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
+      NULL, 0);
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifndef PNG_HANDLE_CHUNK_IF_SAFE
+#    define PNG_HANDLE_CHUNK_IF_SAFE      2
+#  endif
+   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_IF_SAFE,
+      NULL, 0);
+#endif
+
+   pngtest_debug("Reading info struct");
+   png_read_info(read_ptr, read_info_ptr);
+
+   pngtest_debug("Transferring info struct");
+   {
+      int interlace_type, compression_type, filter_type;
+
+      if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth,
+          &color_type, &interlace_type, &compression_type, &filter_type))
+      {
+         png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+            color_type, interlace_type, compression_type, filter_type);
+#else
+            color_type, PNG_INTERLACE_NONE, compression_type, filter_type);
+#endif
+      }
+   }
+#ifdef PNG_FIXED_POINT_SUPPORTED
+#ifdef PNG_cHRM_SUPPORTED
+   {
+      png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+         blue_y;
+
+      if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y,
+         &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y))
+      {
+         png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
+            red_y, green_x, green_y, blue_x, blue_y);
+      }
+   }
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+   {
+      png_fixed_point gamma;
+
+      if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma))
+         png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma);
+   }
+#endif
+#else /* Use floating point versions */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+#ifdef PNG_cHRM_SUPPORTED
+   {
+      double white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+         blue_y;
+
+      if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
+         &red_y, &green_x, &green_y, &blue_x, &blue_y))
+      {
+         png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
+            red_y, green_x, green_y, blue_x, blue_y);
+      }
+   }
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+   {
+      double gamma;
+
+      if (png_get_gAMA(read_ptr, read_info_ptr, &gamma))
+         png_set_gAMA(write_ptr, write_info_ptr, gamma);
+   }
+#endif
+#endif /* Floating point */
+#endif /* Fixed point */
+#ifdef PNG_iCCP_SUPPORTED
+   {
+      png_charp name;
+      png_bytep profile;
+      png_uint_32 proflen;
+      int compression_type;
+
+      if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
+                      &profile, &proflen))
+      {
+         png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
+                      profile, proflen);
+      }
+   }
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+   {
+      int intent;
+
+      if (png_get_sRGB(read_ptr, read_info_ptr, &intent))
+         png_set_sRGB(write_ptr, write_info_ptr, intent);
+   }
+#endif
+   {
+      png_colorp palette;
+      int num_palette;
+
+      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette))
+         png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette);
+   }
+#ifdef PNG_bKGD_SUPPORTED
+   {
+      png_color_16p background;
+
+      if (png_get_bKGD(read_ptr, read_info_ptr, &background))
+      {
+         png_set_bKGD(write_ptr, write_info_ptr, background);
+      }
+   }
+#endif
+#ifdef PNG_hIST_SUPPORTED
+   {
+      png_uint_16p hist;
+
+      if (png_get_hIST(read_ptr, read_info_ptr, &hist))
+         png_set_hIST(write_ptr, write_info_ptr, hist);
+   }
+#endif
+#ifdef PNG_oFFs_SUPPORTED
+   {
+      png_int_32 offset_x, offset_y;
+      int unit_type;
+
+      if (png_get_oFFs(read_ptr, read_info_ptr, &offset_x, &offset_y,
+          &unit_type))
+      {
+         png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type);
+      }
+   }
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+   {
+      png_charp purpose, units;
+      png_charpp params;
+      png_int_32 X0, X1;
+      int type, nparams;
+
+      if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type,
+         &nparams, &units, &params))
+      {
+         png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type,
+            nparams, units, params);
+      }
+   }
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+   {
+      png_uint_32 res_x, res_y;
+      int unit_type;
+
+      if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y, &unit_type))
+         png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type);
+   }
+#endif
+#ifdef PNG_sBIT_SUPPORTED
+   {
+      png_color_8p sig_bit;
+
+      if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit))
+         png_set_sBIT(write_ptr, write_info_ptr, sig_bit);
+   }
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   {
+      int unit;
+      double scal_width, scal_height;
+
+      if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width,
+         &scal_height))
+      {
+         png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height);
+      }
+   }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   {
+      int unit;
+      png_charp scal_width, scal_height;
+
+      if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width,
+          &scal_height))
+      {
+         png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width,
+             scal_height);
+      }
+   }
+#endif
+#endif
+#endif
+#ifdef PNG_TEXT_SUPPORTED
+   {
+      png_textp text_ptr;
+      int num_text;
+
+      if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
+         png_set_text(write_ptr, write_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#ifdef PNG_tIME_SUPPORTED
+   {
+      png_timep mod_time;
+
+      if (png_get_tIME(read_ptr, read_info_ptr, &mod_time))
+      {
+         png_set_tIME(write_ptr, write_info_ptr, mod_time);
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         /* We have to use png_memcpy instead of "=" because the string
+          * pointed to by png_convert_to_rfc1123() gets free'ed before
+          * we use it.
+          */
+         png_memcpy(tIME_string,
+                    png_convert_to_rfc1123(read_ptr, mod_time),
+                    png_sizeof(tIME_string));
+
+         tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+         tIME_chunk_present++;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+      }
+   }
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+   {
+      png_bytep trans_alpha;
+      int num_trans;
+      png_color_16p trans_color;
+
+      if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
+         &trans_color))
+      {
+         int sample_max = (1 << bit_depth);
+         /* libpng doesn't reject a tRNS chunk with out-of-range samples */
+         if (!((color_type == PNG_COLOR_TYPE_GRAY &&
+             (int)trans_color->gray > sample_max) ||
+             (color_type == PNG_COLOR_TYPE_RGB &&
+             ((int)trans_color->red > sample_max ||
+             (int)trans_color->green > sample_max ||
+             (int)trans_color->blue > sample_max))))
+            png_set_tRNS(write_ptr, write_info_ptr, trans_alpha, num_trans,
+               trans_color);
+      }
+   }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr,
+         &unknowns);
+
+      if (num_unknowns)
+      {
+         int i;
+         png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
+           num_unknowns);
+         /* Copy the locations from the read_info_ptr.  The automatically
+          * generated locations in write_info_ptr are wrong because we
+          * haven't written anything yet.
+          */
+         for (i = 0; i < num_unknowns; i++)
+           png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
+             unknowns[i].location);
+      }
+   }
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("Writing info struct");
+
+/* If we wanted, we could write info in two steps:
+ * png_write_info_before_PLTE(write_ptr, write_info_ptr);
+ */
+   png_write_info(write_ptr, write_info_ptr);
+
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+   if (user_chunk_data[0] != 0)
+   {
+      png_byte png_sTER[5] = {115,  84,  69,  82, '\0'};
+
+      unsigned char
+        ster_chunk_data[1];
+
+      if (verbose)
+         fprintf(STDERR, "\n stereo mode = %lu\n",
+           (unsigned long)(user_chunk_data[0] - 1));
+
+      ster_chunk_data[0]=(unsigned char)(user_chunk_data[0] - 1);
+      png_write_chunk(write_ptr, png_sTER, ster_chunk_data, 1);
+   }
+
+   if (user_chunk_data[1] != 0 || user_chunk_data[2] != 0)
+   {
+      png_byte png_vpAg[5] = {118, 112,  65, 103, '\0'};
+
+      unsigned char
+        vpag_chunk_data[9];
+
+      if (verbose)
+         fprintf(STDERR, " vpAg = %lu x %lu, units = %lu\n",
+           (unsigned long)user_chunk_data[1],
+           (unsigned long)user_chunk_data[2],
+           (unsigned long)user_chunk_data[3]);
+
+      png_save_uint_32(vpag_chunk_data, user_chunk_data[1]);
+      png_save_uint_32(vpag_chunk_data + 4, user_chunk_data[2]);
+      vpag_chunk_data[8] = (unsigned char)(user_chunk_data[3] & 0xff);
+      png_write_chunk(write_ptr, png_vpAg, vpag_chunk_data, 9);
+   }
+
+#endif
+#endif
+
+#ifdef SINGLE_ROWBUF_ALLOC
+   pngtest_debug("Allocating row buffer...");
+   row_buf = (png_bytep)png_malloc(read_ptr,
+      png_get_rowbytes(read_ptr, read_info_ptr));
+
+   pngtest_debug1("\t0x%08lx", (unsigned long)row_buf);
+#endif /* SINGLE_ROWBUF_ALLOC */
+   pngtest_debug("Writing row data");
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+  defined(PNG_WRITE_INTERLACING_SUPPORTED)
+   num_pass = png_set_interlace_handling(read_ptr);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_set_interlace_handling(write_ptr);
+#  endif
+#else
+   num_pass = 1;
+#endif
+
+#ifdef PNGTEST_TIMING
+   t_stop = (float)clock();
+   t_misc += (t_stop - t_start);
+   t_start = t_stop;
+#endif
+   for (pass = 0; pass < num_pass; pass++)
+   {
+      pngtest_debug1("Writing row data for pass %d", pass);
+      for (y = 0; y < height; y++)
+      {
+#ifndef SINGLE_ROWBUF_ALLOC
+         pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
+         row_buf = (png_bytep)png_malloc(read_ptr,
+            png_get_rowbytes(read_ptr, read_info_ptr));
+
+         pngtest_debug2("\t0x%08lx (%u bytes)", (unsigned long)row_buf,
+            png_get_rowbytes(read_ptr, read_info_ptr));
+
+#endif /* !SINGLE_ROWBUF_ALLOC */
+         png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNGTEST_TIMING
+         t_stop = (float)clock();
+         t_decode += (t_stop - t_start);
+         t_start = t_stop;
+#endif
+         png_write_rows(write_ptr, (png_bytepp)&row_buf, 1);
+#ifdef PNGTEST_TIMING
+         t_stop = (float)clock();
+         t_encode += (t_stop - t_start);
+         t_start = t_stop;
+#endif
+#endif /* PNG_WRITE_SUPPORTED */
+
+#ifndef SINGLE_ROWBUF_ALLOC
+         pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y);
+         png_free(read_ptr, row_buf);
+         row_buf = NULL;
+#endif /* !SINGLE_ROWBUF_ALLOC */
+      }
+   }
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#endif
+
+   pngtest_debug("Reading and writing end_info data");
+
+   png_read_end(read_ptr, end_info_ptr);
+#ifdef PNG_TEXT_SUPPORTED
+   {
+      png_textp text_ptr;
+      int num_text;
+
+      if (png_get_text(read_ptr, end_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
+         png_set_text(write_ptr, write_end_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#ifdef PNG_tIME_SUPPORTED
+   {
+      png_timep mod_time;
+
+      if (png_get_tIME(read_ptr, end_info_ptr, &mod_time))
+      {
+         png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         /* We have to use png_memcpy instead of "=" because the string
+            pointed to by png_convert_to_rfc1123() gets free'ed before
+            we use it */
+         png_memcpy(tIME_string,
+                    png_convert_to_rfc1123(read_ptr, mod_time),
+                    png_sizeof(tIME_string));
+
+         tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+         tIME_chunk_present++;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+      }
+   }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr,
+         &unknowns);
+
+      if (num_unknowns)
+      {
+         int i;
+         png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
+           num_unknowns);
+         /* Copy the locations from the read_info_ptr.  The automatically
+          * generated locations in write_end_info_ptr are wrong because we
+          * haven't written the end_info yet.
+          */
+         for (i = 0; i < num_unknowns; i++)
+           png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
+             unknowns[i].location);
+      }
+   }
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+   png_write_end(write_ptr, write_end_info_ptr);
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+   if (verbose)
+   {
+      png_uint_32 iwidth, iheight;
+      iwidth = png_get_image_width(write_ptr, write_info_ptr);
+      iheight = png_get_image_height(write_ptr, write_info_ptr);
+      fprintf(STDERR, "\n Image width = %lu, height = %lu\n",
+         (unsigned long)iwidth, (unsigned long)iheight);
+   }
+#endif
+
+   pngtest_debug("Destroying data structs");
+#ifdef SINGLE_ROWBUF_ALLOC
+   pngtest_debug("destroying row_buf for read_ptr");
+   png_free(read_ptr, row_buf);
+   row_buf = NULL;
+#endif /* SINGLE_ROWBUF_ALLOC */
+   pngtest_debug("destroying read_ptr, read_info_ptr, end_info_ptr");
+   png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("destroying write_end_info_ptr");
+   png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+   pngtest_debug("destroying write_ptr, write_info_ptr");
+   png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+   pngtest_debug("Destruction complete.");
+
+   FCLOSE(fpin);
+   FCLOSE(fpout);
+
+   pngtest_debug("Opening files for comparison");
+   if ((fpin = fopen(inname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find file %s\n", inname);
+      return (1);
+   }
+
+   if ((fpout = fopen(outname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find file %s\n", outname);
+      FCLOSE(fpin);
+      return (1);
+   }
+
+   for (;;)
+   {
+      png_size_t num_in, num_out;
+
+         num_in = fread(inbuf, 1, 1, fpin);
+         num_out = fread(outbuf, 1, 1, fpout);
+
+      if (num_in != num_out)
+      {
+         fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
+                 inname, outname);
+
+         if (wrote_question == 0)
+         {
+            fprintf(STDERR,
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+              inname, PNG_ZBUF_SIZE);
+            fprintf(STDERR,
+              "\n   filtering heuristic (libpng default), compression");
+            fprintf(STDERR,
+              " level (zlib default),\n   and zlib version (%s)?\n\n",
+              ZLIB_VERSION);
+            wrote_question = 1;
+         }
+
+         FCLOSE(fpin);
+         FCLOSE(fpout);
+         return (0);
+      }
+
+      if (!num_in)
+         break;
+
+      if (png_memcmp(inbuf, outbuf, num_in))
+      {
+         fprintf(STDERR, "\nFiles %s and %s are different\n", inname, outname);
+
+         if (wrote_question == 0)
+         {
+            fprintf(STDERR,
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                 inname, PNG_ZBUF_SIZE);
+            fprintf(STDERR,
+              "\n   filtering heuristic (libpng default), compression");
+            fprintf(STDERR,
+              " level (zlib default),\n   and zlib version (%s)?\n\n",
+              ZLIB_VERSION);
+            wrote_question = 1;
+         }
+
+         FCLOSE(fpin);
+         FCLOSE(fpout);
+         return (0);
+      }
+   }
+
+   FCLOSE(fpin);
+   FCLOSE(fpout);
+
+   return (0);
+}
+
+/* Input and output filenames */
+#ifdef RISCOS
+static PNG_CONST char *inname = "pngtest/png";
+static PNG_CONST char *outname = "pngout/png";
+#else
+static PNG_CONST char *inname = "pngtest.png";
+static PNG_CONST char *outname = "pngout.png";
+#endif
+
+int
+main(int argc, char *argv[])
+{
+   int multiple = 0;
+   int ierror = 0;
+
+   fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
+   fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
+   fprintf(STDERR, "%s", png_get_copyright(NULL));
+   /* Show the version of libpng used in building the library */
+   fprintf(STDERR, " library (%lu):%s",
+      (unsigned long)png_access_version_number(),
+      png_get_header_version(NULL));
+
+   /* Show the version of libpng used in building the application */
+   fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER,
+      PNG_HEADER_VERSION_STRING);
+
+   /* Do some consistency checking on the memory allocation settings, I'm
+    * not sure this matters, but it is nice to know, the first of these
+    * tests should be impossible because of the way the macros are set
+    * in pngconf.h
+    */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+      fprintf(STDERR, " NOTE: Zlib compiled for max 64k, libpng not\n");
+#endif
+   /* I think the following can happen. */
+#if !defined(MAXSEG_64K) && defined(PNG_MAX_MALLOC_64K)
+      fprintf(STDERR, " NOTE: libpng compiled for max 64k, zlib not\n");
+#endif
+
+   if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING))
+   {
+      fprintf(STDERR,
+         "Warning: versions are different between png.h and png.c\n");
+      fprintf(STDERR, "  png.h version: %s\n", PNG_LIBPNG_VER_STRING);
+      fprintf(STDERR, "  png.c version: %s\n\n", png_libpng_ver);
+      ++ierror;
+   }
+
+   if (argc > 1)
+   {
+      if (strcmp(argv[1], "-m") == 0)
+      {
+         multiple = 1;
+         status_dots_requested = 0;
+      }
+
+      else if (strcmp(argv[1], "-mv") == 0 ||
+               strcmp(argv[1], "-vm") == 0 )
+      {
+         multiple = 1;
+         verbose = 1;
+         status_dots_requested = 1;
+      }
+
+      else if (strcmp(argv[1], "-v") == 0)
+      {
+         verbose = 1;
+         status_dots_requested = 1;
+         inname = argv[2];
+      }
+
+      else
+      {
+         inname = argv[1];
+         status_dots_requested = 0;
+      }
+   }
+
+   if (!multiple && argc == 3 + verbose)
+     outname = argv[2 + verbose];
+
+   if ((!multiple && argc > 3 + verbose) || (multiple && argc < 2))
+   {
+     fprintf(STDERR,
+       "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
+        argv[0], argv[0]);
+     fprintf(STDERR,
+       "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
+     fprintf(STDERR,
+       "  with -m %s is used as a temporary file\n", outname);
+     exit(1);
+   }
+
+   if (multiple)
+   {
+      int i;
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+      int allocation_now = current_allocation;
+#endif
+      for (i=2; i<argc; ++i)
+      {
+         int kerror;
+         fprintf(STDERR, "\n Testing %s:", argv[i]);
+         kerror = test_one_file(argv[i], outname);
+         if (kerror == 0)
+         {
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+            int k;
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+            fprintf(STDERR, "\n PASS (%lu zero samples)\n",
+               (unsigned long)zero_samples);
+#else
+            fprintf(STDERR, " PASS\n");
+#endif
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+            for (k = 0; k<256; k++)
+               if (filters_used[k])
+                  fprintf(STDERR, " Filter %d was used %lu times\n",
+                     k, (unsigned long)filters_used[k]);
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         if (tIME_chunk_present != 0)
+            fprintf(STDERR, " tIME = %s\n", tIME_string);
+
+         tIME_chunk_present = 0;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+         }
+
+         else
+         {
+            fprintf(STDERR, " FAIL\n");
+            ierror += kerror;
+         }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         if (allocation_now != current_allocation)
+            fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
+               current_allocation - allocation_now);
+
+         if (current_allocation != 0)
+         {
+            memory_infop pinfo = pinformation;
+
+            fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
+               current_allocation);
+
+            while (pinfo != NULL)
+            {
+               fprintf(STDERR, " %lu bytes at %x\n",
+                 (unsigned long)pinfo->size,
+                 (unsigned int)pinfo->pointer);
+               pinfo = pinfo->next;
+            }
+         }
+#endif
+      }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         fprintf(STDERR, " Current memory allocation: %10d bytes\n",
+            current_allocation);
+         fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
+            maximum_allocation);
+         fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
+            total_allocation);
+         fprintf(STDERR, "     Number of allocations: %10d\n",
+            num_allocations);
+#endif
+   }
+
+   else
+   {
+      int i;
+      for (i = 0; i<3; ++i)
+      {
+         int kerror;
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         int allocation_now = current_allocation;
+#endif
+         if (i == 1)
+            status_dots_requested = 1;
+
+         else if (verbose == 0)
+            status_dots_requested = 0;
+
+         if (i == 0 || verbose == 1 || ierror != 0)
+            fprintf(STDERR, "\n Testing %s:", inname);
+
+         kerror = test_one_file(inname, outname);
+
+         if (kerror == 0)
+         {
+            if (verbose == 1 || i == 2)
+            {
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+                int k;
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+                fprintf(STDERR, "\n PASS (%lu zero samples)\n",
+                   (unsigned long)zero_samples);
+#else
+                fprintf(STDERR, " PASS\n");
+#endif
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+                for (k = 0; k<256; k++)
+                   if (filters_used[k])
+                      fprintf(STDERR, " Filter %d was used %lu times\n",
+                         k, (unsigned long)filters_used[k]);
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+             if (tIME_chunk_present != 0)
+                fprintf(STDERR, " tIME = %s\n", tIME_string);
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+            }
+         }
+
+         else
+         {
+            if (verbose == 0 && i != 2)
+               fprintf(STDERR, "\n Testing %s:", inname);
+
+            fprintf(STDERR, " FAIL\n");
+            ierror += kerror;
+         }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         if (allocation_now != current_allocation)
+             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
+               current_allocation - allocation_now);
+
+         if (current_allocation != 0)
+         {
+             memory_infop pinfo = pinformation;
+
+             fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
+                current_allocation);
+
+             while (pinfo != NULL)
+             {
+                fprintf(STDERR, " %lu bytes at %x\n",
+                   (unsigned long)pinfo->size, (unsigned int)pinfo->pointer);
+                pinfo = pinfo->next;
+             }
+          }
+#endif
+       }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+       fprintf(STDERR, " Current memory allocation: %10d bytes\n",
+          current_allocation);
+       fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
+          maximum_allocation);
+       fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
+          total_allocation);
+       fprintf(STDERR, "     Number of allocations: %10d\n",
+            num_allocations);
+#endif
+   }
+
+#ifdef PNGTEST_TIMING
+   t_stop = (float)clock();
+   t_misc += (t_stop - t_start);
+   t_start = t_stop;
+   fprintf(STDERR, " CPU time used = %.3f seconds",
+      (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, " (decoding %.3f,\n",
+      t_decode/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, "        encoding %.3f ,",
+      t_encode/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, " other %.3f seconds)\n\n",
+      t_misc/(float)CLOCKS_PER_SEC);
+#endif
+
+   if (ierror == 0)
+      fprintf(STDERR, " libpng passes test\n");
+
+   else
+      fprintf(STDERR, " libpng FAILS test\n");
+
+   return (int)(ierror != 0);
+}
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef png_libpng_version_1_5_4 Your_png_h_is_not_version_1_5_4;