Don't overwrite status message when restoring it if it changed.

[wxWidgets.git] / src / png / pngread.c

diff --git a/src/png/pngread.c b/src/png/pngread.c
index 31019304c025852ecebf004725cca42c96872a64..68b58582659d2ef6442fffb7278e612cd25d0e34 100644 (file)
--- a/src/png/pngread.c
+++ b/src/png/pngread.c
@@ -1,9 +1,9 @@
 
 /* pngread.c - read a PNG file
  *
 
 /* pngread.c - read a PNG file
  *

- * libpng 1.2.5rc3 - September 18, 2002
+ * Last changed in libpng 1.2.30 [August 15, 2008]

  * For conditions of distribution and use, see copyright notice in png.h
  * For conditions of distribution and use, see copyright notice in png.h

- * Copyright (c) 1998-2002 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 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.)
  *
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *


@@ -13,6 +13,7 @@
 
 #define PNG_INTERNAL
 #include "png.h"
 
 #define PNG_INTERNAL
 #include "png.h"

+#if defined(PNG_READ_SUPPORTED)

 
 /* Create a PNG structure for reading, and allocate any memory needed. */
 png_structp PNGAPI
 
 /* Create a PNG structure for reading, and allocate any memory needed. */
 png_structp PNGAPI


@@ -33,6 +34,9 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
 
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
 

+#ifdef PNG_SETJMP_SUPPORTED
+   volatile
+#endif

    png_structp png_ptr;
 
 #ifdef PNG_SETJMP_SUPPORTED
    png_structp png_ptr;
 
 #ifdef PNG_SETJMP_SUPPORTED


@@ -43,7 +47,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 
    int i;
 
 
    int i;
 

-   png_debug(1, "in png_create_read_struct\n");
+   png_debug(1, "in png_create_read_struct");

 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);


@@ -53,11 +57,11 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
    if (png_ptr == NULL)
       return (NULL);
 
    if (png_ptr == NULL)
       return (NULL);
 

-#if !defined(PNG_1_0_X)
-#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
-   png_init_mmx_flags(png_ptr);   /* 1.2.0 addition */
+   /* added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
+   png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;

 #endif
 #endif

-#endif /* PNG_1_0_X */

 
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
 
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD


@@ -67,9 +71,9 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif
    {
       png_free(png_ptr, png_ptr->zbuf);
 #endif
    {
       png_free(png_ptr, png_ptr->zbuf);

-      png_ptr->zbuf=NULL;
+      png_ptr->zbuf = NULL;

 #ifdef PNG_USER_MEM_SUPPORTED
 #ifdef PNG_USER_MEM_SUPPORTED

-      png_destroy_struct_2((png_voidp)png_ptr, 
+      png_destroy_struct_2((png_voidp)png_ptr,

          (png_free_ptr)free_fn, (png_voidp)mem_ptr);
 #else
       png_destroy_struct((png_voidp)png_ptr);
          (png_free_ptr)free_fn, (png_voidp)mem_ptr);
 #else
       png_destroy_struct((png_voidp)png_ptr);


@@ -77,7 +81,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
       return (NULL);
    }
 #ifdef USE_FAR_KEYWORD
       return (NULL);
    }
 #ifdef USE_FAR_KEYWORD

-   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));

 #endif
 #endif
 
 #endif
 #endif
 


@@ -87,12 +91,18 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 

-   i=0;
-   do
+   if (user_png_ver)

    {
    {

-     if(user_png_ver[i] != png_libpng_ver[i])
+     i = 0;
+     do
+     {
+       if (user_png_ver[i] != png_libpng_ver[i])
+          png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+     } while (png_libpng_ver[i++]);
+   }
+   else

         png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
         png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;

-   } while (png_libpng_ver[i++]);
+   

 
    if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
    {
 
    if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
    {


@@ -109,16 +119,18 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
         char msg[80];
         if (user_png_ver)
         {
         char msg[80];
         if (user_png_ver)
         {

-          sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
+          png_snprintf(msg, 80,
+             "Application was compiled with png.h from libpng-%.20s",

              user_png_ver);
           png_warning(png_ptr, msg);
         }
              user_png_ver);
           png_warning(png_ptr, msg);
         }

-        sprintf(msg, "Application  is  running with png.c from libpng-%.20s",
+        png_snprintf(msg, 80,
+             "Application  is  running with png.c from libpng-%.20s",

            png_libpng_ver);
         png_warning(png_ptr, msg);
 #endif
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
            png_libpng_ver);
         png_warning(png_ptr, msg);
 #endif
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED

-        png_ptr->flags=0;
+        png_ptr->flags = 0;

 #endif
         png_error(png_ptr,
            "Incompatible libpng version in application and library");
 #endif
         png_error(png_ptr,
            "Incompatible libpng version in application and library");


@@ -154,7 +166,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
       PNG_ABORT();
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
       PNG_ABORT();

-   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));

 #else
    if (setjmp(png_ptr->jmpbuf))
       PNG_ABORT();
 #else
    if (setjmp(png_ptr->jmpbuf))
       PNG_ABORT();


@@ -163,9 +175,10 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
    return (png_ptr);
 }
 
    return (png_ptr);
 }
 

+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)

 /* Initialize PNG structure for reading, and allocate any memory needed.
    This interface is deprecated in favour of the png_create_read_struct(),
 /* Initialize PNG structure for reading, and allocate any memory needed.
    This interface is deprecated in favour of the png_create_read_struct(),

-   and it will eventually disappear. */
+   and it will disappear as of libpng-1.3.0. */

 #undef png_read_init
 void PNGAPI
 png_read_init(png_structp png_ptr)
 #undef png_read_init
 void PNGAPI
 png_read_init(png_structp png_ptr)


@@ -179,42 +192,47 @@ png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
    png_size_t png_struct_size, png_size_t png_info_size)
 {
    /* We only come here via pre-1.0.12-compiled applications */
    png_size_t png_struct_size, png_size_t png_info_size)
 {
    /* We only come here via pre-1.0.12-compiled applications */

+   if (png_ptr == NULL) return;

 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)

-   if(sizeof(png_struct) > png_struct_size || sizeof(png_info) > png_info_size)
+   if (png_sizeof(png_struct) > png_struct_size ||
+      png_sizeof(png_info) > png_info_size)

    {
       char msg[80];
    {
       char msg[80];

-      png_ptr->warning_fn=NULL;
+      png_ptr->warning_fn = NULL;

       if (user_png_ver)
       {
       if (user_png_ver)
       {

-        sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
+        png_snprintf(msg, 80,
+           "Application was compiled with png.h from libpng-%.20s",

            user_png_ver);
         png_warning(png_ptr, msg);
       }
            user_png_ver);
         png_warning(png_ptr, msg);
       }

-      sprintf(msg, "Application  is  running with png.c from libpng-%.20s",
+      png_snprintf(msg, 80,
+         "Application  is  running with png.c from libpng-%.20s",

          png_libpng_ver);
       png_warning(png_ptr, msg);
    }
 #endif
          png_libpng_ver);
       png_warning(png_ptr, msg);
    }
 #endif

-   if(sizeof(png_struct) > png_struct_size)
+   if (png_sizeof(png_struct) > png_struct_size)

      {
      {

-       png_ptr->error_fn=NULL;
+       png_ptr->error_fn = NULL;

 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED

-       png_ptr->flags=0;
+       png_ptr->flags = 0;

 #endif
        png_error(png_ptr,
        "The png struct allocated by the application for reading is too small.");
      }
 #endif
        png_error(png_ptr,
        "The png struct allocated by the application for reading is too small.");
      }

-   if(sizeof(png_info) > png_info_size)
+   if (png_sizeof(png_info) > png_info_size)

      {
      {

-       png_ptr->error_fn=NULL;
+       png_ptr->error_fn = NULL;

 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED

-       png_ptr->flags=0;
+       png_ptr->flags = 0;

 #endif
        png_error(png_ptr,
          "The info struct allocated by application for reading is too small.");
      }
    png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
 }
 #endif
        png_error(png_ptr,
          "The info struct allocated by application for reading is too small.");
      }
    png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
 }

+#endif /* PNG_1_0_X || PNG_1_2_X */

 
 void PNGAPI
 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 
 void PNGAPI
 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,


@@ -224,18 +242,20 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
    jmp_buf tmp_jmp;  /* to save current jump buffer */
 #endif
 
    jmp_buf tmp_jmp;  /* to save current jump buffer */
 #endif
 

-   int i=0;
+   int i = 0;

 
    png_structp png_ptr=*ptr_ptr;
 
 
    png_structp png_ptr=*ptr_ptr;
 

+   if (png_ptr == NULL) return;
+

    do
    {
    do
    {

-     if(user_png_ver[i] != png_libpng_ver[i])
+     if (user_png_ver[i] != png_libpng_ver[i])

      {
 #ifdef PNG_LEGACY_SUPPORTED
        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 #else
      {
 #ifdef PNG_LEGACY_SUPPORTED
        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 #else

-       png_ptr->warning_fn=NULL;
+       png_ptr->warning_fn = NULL;

        png_warning(png_ptr,
         "Application uses deprecated png_read_init() and should be recompiled.");
        break;
        png_warning(png_ptr,
         "Application uses deprecated png_read_init() and should be recompiled.");
        break;


@@ -243,26 +263,32 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
      }
    } while (png_libpng_ver[i++]);
 
      }
    } while (png_libpng_ver[i++]);
 

-   png_debug(1, "in png_read_init_3\n");
+   png_debug(1, "in png_read_init_3");

 
 #ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */

-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));

 #endif
 
 #endif
 

-   if(sizeof(png_struct) > png_struct_size)
-     {
-       png_destroy_struct(png_ptr);
-       *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
-       png_ptr = *ptr_ptr;
-     }
+   if (png_sizeof(png_struct) > png_struct_size)
+   {
+      png_destroy_struct(png_ptr);
+      *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+      png_ptr = *ptr_ptr;
+   }

 
    /* reset all variables to 0 */
 
    /* reset all variables to 0 */

-   png_memset(png_ptr, 0, sizeof (png_struct));
+   png_memset(png_ptr, 0, png_sizeof(png_struct));

 
 #ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */

-   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+
+   /* added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
+   png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;

 #endif
 
    /* initialize zbuf - compression buffer */
 #endif
 
    /* initialize zbuf - compression buffer */


@@ -288,6 +314,7 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
    png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
 }
 
    png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
 }
 

+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 /* Read the information before the actual image data.  This has been
  * changed in v0.90 to allow reading a file that already has the magic
  * bytes read from the stream.  You can tell libpng how many bytes have
 /* Read the information before the actual image data.  This has been
  * changed in v0.90 to allow reading a file that already has the magic
  * bytes read from the stream.  You can tell libpng how many bytes have


@@ -299,7 +326,8 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 void PNGAPI
 png_read_info(png_structp png_ptr, png_infop info_ptr)
 {
 void PNGAPI
 png_read_info(png_structp png_ptr, png_infop info_ptr)
 {

-   png_debug(1, "in png_read_info\n");
+   if (png_ptr == NULL || info_ptr == NULL) return;
+   png_debug(1, "in png_read_info");

    /* If we haven't checked all of the PNG signature bytes, do so now. */
    if (png_ptr->sig_bytes < 8)
    {
    /* If we haven't checked all of the PNG signature bytes, do so now. */
    if (png_ptr->sig_bytes < 8)
    {


@@ -321,96 +349,88 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
    }
 
          png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
    }
 

-   for(;;)
+   for (;;)

    {
 #ifdef PNG_USE_LOCAL_ARRAYS
    {
 #ifdef PNG_USE_LOCAL_ARRAYS

-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
+      PNG_CONST PNG_IHDR;
+      PNG_CONST PNG_IDAT;
+      PNG_CONST PNG_IEND;
+      PNG_CONST PNG_PLTE;

 #if defined(PNG_READ_bKGD_SUPPORTED)
 #if defined(PNG_READ_bKGD_SUPPORTED)

-      PNG_bKGD;
+      PNG_CONST PNG_bKGD;

 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)

-      PNG_cHRM;
+      PNG_CONST PNG_cHRM;

 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)

-      PNG_gAMA;
+      PNG_CONST PNG_gAMA;

 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)

-      PNG_hIST;
+      PNG_CONST PNG_hIST;

 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)

-      PNG_iCCP;
+      PNG_CONST PNG_iCCP;

 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)

-      PNG_iTXt;
+      PNG_CONST PNG_iTXt;

 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)

-      PNG_oFFs;
+      PNG_CONST PNG_oFFs;

 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)

-      PNG_pCAL;
+      PNG_CONST PNG_pCAL;

 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)

-      PNG_pHYs;
+      PNG_CONST PNG_pHYs;

 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)

-      PNG_sBIT;
+      PNG_CONST PNG_sBIT;

 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)

-      PNG_sCAL;
+      PNG_CONST PNG_sCAL;

 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)

-      PNG_sPLT;
+      PNG_CONST PNG_sPLT;

 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)

-      PNG_sRGB;
+      PNG_CONST PNG_sRGB;

 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)

-      PNG_tEXt;
+      PNG_CONST PNG_tEXt;

 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)

-      PNG_tIME;
+      PNG_CONST PNG_tIME;

 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)

-      PNG_tRNS;
+      PNG_CONST PNG_tRNS;

 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)

-      PNG_zTXt;
+      PNG_CONST PNG_zTXt;

 #endif
 #endif

-#endif /* PNG_GLOBAL_ARRAYS */
-      png_byte chunk_length[4];
-      png_uint_32 length;
-
-      png_read_data(png_ptr, chunk_length, 4);
-      length = png_get_uint_32(chunk_length);
-
-      png_reset_crc(png_ptr);
-      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-
-      png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
-         length);
-
-      if (length > PNG_MAX_UINT)
-         png_error(png_ptr, "Invalid chunk length.");
+#endif /* PNG_USE_LOCAL_ARRAYS */
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;

 
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
        */
 
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
        */

-      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+      if (!png_memcmp(chunk_name, png_IDAT, 4))
+        if (png_ptr->mode & PNG_AFTER_IDAT)
+          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+      if (!png_memcmp(chunk_name, png_IHDR, 4))

          png_handle_IHDR(png_ptr, info_ptr, length);
          png_handle_IHDR(png_ptr, info_ptr, length);

-      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+      else if (!png_memcmp(chunk_name, png_IEND, 4))

          png_handle_IEND(png_ptr, info_ptr, length);
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
          png_handle_IEND(png_ptr, info_ptr, length);
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED

-      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+      else if (png_handle_as_unknown(png_ptr, chunk_name))

       {
       {

-         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         if (!png_memcmp(chunk_name, png_IDAT, 4))

             png_ptr->mode |= PNG_HAVE_IDAT;
          png_handle_unknown(png_ptr, info_ptr, length);
             png_ptr->mode |= PNG_HAVE_IDAT;
          png_handle_unknown(png_ptr, info_ptr, length);

-         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+         if (!png_memcmp(chunk_name, png_PLTE, 4))

             png_ptr->mode |= PNG_HAVE_PLTE;
             png_ptr->mode |= PNG_HAVE_PLTE;

-         else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         else if (!png_memcmp(chunk_name, png_IDAT, 4))

          {
             if (!(png_ptr->mode & PNG_HAVE_IHDR))
                png_error(png_ptr, "Missing IHDR before IDAT");
          {
             if (!(png_ptr->mode & PNG_HAVE_IHDR))
                png_error(png_ptr, "Missing IHDR before IDAT");


@@ -421,9 +441,9 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          }
       }
 #endif
          }
       }
 #endif

-      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+      else if (!png_memcmp(chunk_name, png_PLTE, 4))

          png_handle_PLTE(png_ptr, info_ptr, length);
          png_handle_PLTE(png_ptr, info_ptr, length);

-      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      else if (!png_memcmp(chunk_name, png_IDAT, 4))

       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");


@@ -436,83 +456,85 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          break;
       }
 #if defined(PNG_READ_bKGD_SUPPORTED)
          break;
       }
 #if defined(PNG_READ_bKGD_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+      else if (!png_memcmp(chunk_name, png_bKGD, 4))

          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+      else if (!png_memcmp(chunk_name, png_cHRM, 4))

          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+      else if (!png_memcmp(chunk_name, png_gAMA, 4))

          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+      else if (!png_memcmp(chunk_name, png_hIST, 4))

          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+      else if (!png_memcmp(chunk_name, png_oFFs, 4))

          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+      else if (!png_memcmp(chunk_name, png_pCAL, 4))

          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+      else if (!png_memcmp(chunk_name, png_sCAL, 4))

          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+      else if (!png_memcmp(chunk_name, png_pHYs, 4))

          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+      else if (!png_memcmp(chunk_name, png_sBIT, 4))

          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+      else if (!png_memcmp(chunk_name, png_sRGB, 4))

          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+      else if (!png_memcmp(chunk_name, png_iCCP, 4))

          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+      else if (!png_memcmp(chunk_name, png_sPLT, 4))

          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+      else if (!png_memcmp(chunk_name, png_tEXt, 4))

          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+      else if (!png_memcmp(chunk_name, png_tIME, 4))

          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+      else if (!png_memcmp(chunk_name, png_tRNS, 4))

          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+      else if (!png_memcmp(chunk_name, png_zTXt, 4))

          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+      else if (!png_memcmp(chunk_name, png_iTXt, 4))

          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
          png_handle_unknown(png_ptr, info_ptr, length);
    }
 }
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
          png_handle_unknown(png_ptr, info_ptr, length);
    }
 }

+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */

 
 /* optional call to update the users info_ptr structure */
 void PNGAPI
 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 {
 
 /* optional call to update the users info_ptr structure */
 void PNGAPI
 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 {

-   png_debug(1, "in png_read_update_info\n");
+   png_debug(1, "in png_read_update_info");
+   if (png_ptr == NULL) return;

    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
    else
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
    else


@@ -521,6 +543,7 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
    png_read_transform_info(png_ptr, info_ptr);
 }
 
    png_read_transform_info(png_ptr, info_ptr);
 }
 

+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 /* Initialize palette, background, etc, after transformations
  * are set, but before any reading takes place.  This allows
  * the user to obtain a gamma-corrected palette, for example.
 /* Initialize palette, background, etc, after transformations
  * are set, but before any reading takes place.  This allows
  * the user to obtain a gamma-corrected palette, for example.


@@ -529,21 +552,26 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 void PNGAPI
 png_start_read_image(png_structp png_ptr)
 {
 void PNGAPI
 png_start_read_image(png_structp png_ptr)
 {

-   png_debug(1, "in png_start_read_image\n");
+   png_debug(1, "in png_start_read_image");
+   if (png_ptr == NULL) return;

    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
 }
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
 }

+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */

 
 

+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 void PNGAPI
 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS
 void PNGAPI
 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS

-   PNG_IDAT;
-   const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
-   const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+   PNG_CONST PNG_IDAT;
+   PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
+      0xff};
+   PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};

 #endif
    int ret;
 #endif
    int ret;

-   png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
+   if (png_ptr == NULL) return;
+   png_debug2(1, "in png_read_row (row %lu, pass %d)",

       png_ptr->row_number, png_ptr->pass);
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
       png_ptr->row_number, png_ptr->pass);
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);


@@ -668,18 +696,9 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
       {
          while (!png_ptr->idat_size)
          {
       {
          while (!png_ptr->idat_size)
          {

-            png_byte chunk_length[4];
-

             png_crc_finish(png_ptr, 0);
 
             png_crc_finish(png_ptr, 0);
 

-            png_read_data(png_ptr, chunk_length, 4);
-            png_ptr->idat_size = png_get_uint_32(chunk_length);
-
-            if (png_ptr->idat_size > PNG_MAX_UINT)
-              png_error(png_ptr, "Invalid chunk length.");
-
-            png_reset_crc(png_ptr);
-            png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+            png_ptr->idat_size = png_read_chunk_header(png_ptr);

             if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
                png_error(png_ptr, "Not enough image data");
          }
             if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
                png_error(png_ptr, "Not enough image data");
          }


@@ -712,19 +731,19 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    png_ptr->row_info.channels = png_ptr->channels;
    png_ptr->row_info.bit_depth = png_ptr->bit_depth;
    png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
    png_ptr->row_info.channels = png_ptr->channels;
    png_ptr->row_info.bit_depth = png_ptr->bit_depth;
    png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;

-   png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
-      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
+   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+       png_ptr->row_info.width);

 
 

-   if(png_ptr->row_buf[0])
+   if (png_ptr->row_buf[0])

    png_read_filter_row(png_ptr, &(png_ptr->row_info),
       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
       (int)(png_ptr->row_buf[0]));
 
    png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
       png_ptr->rowbytes + 1);
    png_read_filter_row(png_ptr, &(png_ptr->row_info),
       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
       (int)(png_ptr->row_buf[0]));
 
    png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
       png_ptr->rowbytes + 1);

-   
+

 #if defined(PNG_MNG_FEATURES_SUPPORTED)
 #if defined(PNG_MNG_FEATURES_SUPPORTED)

-   if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&

       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */


@@ -732,7 +751,8 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    }
 #endif
 
    }
 #endif
 

-   if (png_ptr->transformations)
+
+   if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))

       png_do_read_transformations(png_ptr);
 
 #if defined(PNG_READ_INTERLACING_SUPPORTED)
       png_do_read_transformations(png_ptr);
 
 #if defined(PNG_READ_INTERLACING_SUPPORTED)


@@ -767,7 +787,9 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    if (png_ptr->read_row_fn != NULL)
       (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
 }
    if (png_ptr->read_row_fn != NULL)
       (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
 }

+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */

 
 

+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 /* Read one or more rows of image data.  If the image is interlaced,
  * and png_set_interlace_handling() has been called, the rows need to
  * contain the contents of the rows from the previous pass.  If the
 /* Read one or more rows of image data.  If the image is interlaced,
  * and png_set_interlace_handling() has been called, the rows need to
  * contain the contents of the rows from the previous pass.  If the


@@ -789,7 +811,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
  * not called png_set_interlace_handling(), the display_row buffer will
  * be ignored, so pass NULL to it.
  *
  * not called png_set_interlace_handling(), the display_row buffer will
  * be ignored, so pass NULL to it.
  *

- * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.5rc3
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng

  */
 
 void PNGAPI
  */
 
 void PNGAPI


@@ -800,7 +822,8 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
    png_bytepp rp;
    png_bytepp dp;
 
    png_bytepp rp;
    png_bytepp dp;
 

-   png_debug(1, "in png_read_rows\n");
+   png_debug(1, "in png_read_rows");
+   if (png_ptr == NULL) return;

    rp = row;
    dp = display_row;
    if (rp != NULL && dp != NULL)
    rp = row;
    dp = display_row;
    if (rp != NULL && dp != NULL)


@@ -811,14 +834,14 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
 
          png_read_row(png_ptr, rptr, dptr);
       }
 
          png_read_row(png_ptr, rptr, dptr);
       }

-   else if(rp != NULL)
+   else if (rp != NULL)

       for (i = 0; i < num_rows; i++)
       {
          png_bytep rptr = *rp;
          png_read_row(png_ptr, rptr, png_bytep_NULL);
          rp++;
       }
       for (i = 0; i < num_rows; i++)
       {
          png_bytep rptr = *rp;
          png_read_row(png_ptr, rptr, png_bytep_NULL);
          rp++;
       }

-   else if(dp != NULL)
+   else if (dp != NULL)

       for (i = 0; i < num_rows; i++)
       {
          png_bytep dptr = *dp;
       for (i = 0; i < num_rows; i++)
       {
          png_bytep dptr = *dp;


@@ -826,7 +849,9 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
          dp++;
       }
 }
          dp++;
       }
 }

+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */

 
 

+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 /* Read the entire image.  If the image has an alpha channel or a tRNS
  * chunk, and you have called png_handle_alpha()[*], you will need to
  * initialize the image to the current image that PNG will be overlaying.
 /* Read the entire image.  If the image has an alpha channel or a tRNS
  * chunk, and you have called png_handle_alpha()[*], you will need to
  * initialize the image to the current image that PNG will be overlaying.


@@ -837,16 +862,17 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
  * only call this function once.  If you desire to have an image for
  * each pass of a interlaced image, use png_read_rows() instead.
  *
  * only call this function once.  If you desire to have an image for
  * each pass of a interlaced image, use png_read_rows() instead.
  *

- * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.5rc3
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng

  */
 void PNGAPI
 png_read_image(png_structp png_ptr, png_bytepp image)
 {
  */
 void PNGAPI
 png_read_image(png_structp png_ptr, png_bytepp image)
 {

-   png_uint_32 i,image_height;
+   png_uint_32 i, image_height;

    int pass, j;
    png_bytepp rp;
 
    int pass, j;
    png_bytepp rp;
 

-   png_debug(1, "in png_read_image\n");
+   png_debug(1, "in png_read_image");
+   if (png_ptr == NULL) return;

 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    pass = png_set_interlace_handling(png_ptr);
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    pass = png_set_interlace_handling(png_ptr);


@@ -871,7 +897,9 @@ png_read_image(png_structp png_ptr, png_bytepp image)
       }
    }
 }
       }
    }
 }

+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */

 
 

+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 /* Read the end of the PNG file.  Will not read past the end of the
  * file, will verify the end is accurate, and will read any comments
  * or time information at the end of the file, if info is not NULL.
 /* Read the end of the PNG file.  Will not read past the end of the
  * file, will verify the end is accurate, and will read any comments
  * or time information at the end of the file, if info is not NULL.


@@ -879,185 +907,173 @@ png_read_image(png_structp png_ptr, png_bytepp image)
 void PNGAPI
 png_read_end(png_structp png_ptr, png_infop info_ptr)
 {
 void PNGAPI
 png_read_end(png_structp png_ptr, png_infop info_ptr)
 {

-   png_byte chunk_length[4];
-   png_uint_32 length;
-
-   png_debug(1, "in png_read_end\n");
+   png_debug(1, "in png_read_end");
+   if (png_ptr == NULL) return;

    png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
 
    do
    {
 #ifdef PNG_USE_LOCAL_ARRAYS
    png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
 
    do
    {
 #ifdef PNG_USE_LOCAL_ARRAYS

-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
+      PNG_CONST PNG_IHDR;
+      PNG_CONST PNG_IDAT;
+      PNG_CONST PNG_IEND;
+      PNG_CONST PNG_PLTE;

 #if defined(PNG_READ_bKGD_SUPPORTED)
 #if defined(PNG_READ_bKGD_SUPPORTED)

-      PNG_bKGD;
+      PNG_CONST PNG_bKGD;

 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)

-      PNG_cHRM;
+      PNG_CONST PNG_cHRM;

 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)

-      PNG_gAMA;
+      PNG_CONST PNG_gAMA;

 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)

-      PNG_hIST;
+      PNG_CONST PNG_hIST;

 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)

-      PNG_iCCP;
+      PNG_CONST PNG_iCCP;

 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)

-      PNG_iTXt;
+      PNG_CONST PNG_iTXt;

 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)

-      PNG_oFFs;
+      PNG_CONST PNG_oFFs;

 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)

-      PNG_pCAL;
+      PNG_CONST PNG_pCAL;

 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)

-      PNG_pHYs;
+      PNG_CONST PNG_pHYs;

 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)

-      PNG_sBIT;
+      PNG_CONST PNG_sBIT;

 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)

-      PNG_sCAL;
+      PNG_CONST PNG_sCAL;

 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)

-      PNG_sPLT;
+      PNG_CONST PNG_sPLT;

 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)

-      PNG_sRGB;
+      PNG_CONST PNG_sRGB;

 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)

-      PNG_tEXt;
+      PNG_CONST PNG_tEXt;

 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)

-      PNG_tIME;
+      PNG_CONST PNG_tIME;

 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)

-      PNG_tRNS;
+      PNG_CONST PNG_tRNS;

 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)

-      PNG_zTXt;
+      PNG_CONST PNG_zTXt;

 #endif
 #endif

-#endif /* PNG_GLOBAL_ARRAYS */
+#endif /* PNG_USE_LOCAL_ARRAYS */
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;

 
 

-      png_read_data(png_ptr, chunk_length, 4);
-      length = png_get_uint_32(chunk_length);
-
-      png_reset_crc(png_ptr);
-      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-
-      png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
-
-      if (length > PNG_MAX_UINT)
-         png_error(png_ptr, "Invalid chunk length.");
-
-      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+      if (!png_memcmp(chunk_name, png_IHDR, 4))

          png_handle_IHDR(png_ptr, info_ptr, length);
          png_handle_IHDR(png_ptr, info_ptr, length);

-      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+      else if (!png_memcmp(chunk_name, png_IEND, 4))

          png_handle_IEND(png_ptr, info_ptr, length);
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
          png_handle_IEND(png_ptr, info_ptr, length);
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED

-      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+      else if (png_handle_as_unknown(png_ptr, chunk_name))

       {
       {

-         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         if (!png_memcmp(chunk_name, png_IDAT, 4))

          {
          {

-            if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
+            if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))

                png_error(png_ptr, "Too many IDAT's found");
          }
                png_error(png_ptr, "Too many IDAT's found");
          }

-         else
-            png_ptr->mode |= PNG_AFTER_IDAT;

          png_handle_unknown(png_ptr, info_ptr, length);
          png_handle_unknown(png_ptr, info_ptr, length);

-         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+         if (!png_memcmp(chunk_name, png_PLTE, 4))

             png_ptr->mode |= PNG_HAVE_PLTE;
       }
 #endif
             png_ptr->mode |= PNG_HAVE_PLTE;
       }
 #endif

-      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      else if (!png_memcmp(chunk_name, png_IDAT, 4))

       {
          /* Zero length IDATs are legal after the last IDAT has been
           * read, but not after other chunks have been read.
           */
       {
          /* Zero length IDATs are legal after the last IDAT has been
           * read, but not after other chunks have been read.
           */

-         if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
+         if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))

             png_error(png_ptr, "Too many IDAT's found");
          png_crc_finish(png_ptr, length);
       }
             png_error(png_ptr, "Too many IDAT's found");
          png_crc_finish(png_ptr, length);
       }

-      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+      else if (!png_memcmp(chunk_name, png_PLTE, 4))

          png_handle_PLTE(png_ptr, info_ptr, length);
 #if defined(PNG_READ_bKGD_SUPPORTED)
          png_handle_PLTE(png_ptr, info_ptr, length);
 #if defined(PNG_READ_bKGD_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+      else if (!png_memcmp(chunk_name, png_bKGD, 4))

          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+      else if (!png_memcmp(chunk_name, png_cHRM, 4))

          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+      else if (!png_memcmp(chunk_name, png_gAMA, 4))

          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+      else if (!png_memcmp(chunk_name, png_hIST, 4))

          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+      else if (!png_memcmp(chunk_name, png_oFFs, 4))

          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+      else if (!png_memcmp(chunk_name, png_pCAL, 4))

          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+      else if (!png_memcmp(chunk_name, png_sCAL, 4))

          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+      else if (!png_memcmp(chunk_name, png_pHYs, 4))

          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+      else if (!png_memcmp(chunk_name, png_sBIT, 4))

          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+      else if (!png_memcmp(chunk_name, png_sRGB, 4))

          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+      else if (!png_memcmp(chunk_name, png_iCCP, 4))

          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+      else if (!png_memcmp(chunk_name, png_sPLT, 4))

          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+      else if (!png_memcmp(chunk_name, png_tEXt, 4))

          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+      else if (!png_memcmp(chunk_name, png_tIME, 4))

          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+      else if (!png_memcmp(chunk_name, png_tRNS, 4))

          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+      else if (!png_memcmp(chunk_name, png_zTXt, 4))

          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)

-      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+      else if (!png_memcmp(chunk_name, png_iTXt, 4))

          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
          png_handle_unknown(png_ptr, info_ptr, length);
    } while (!(png_ptr->mode & PNG_HAVE_IEND));
 }
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
          png_handle_unknown(png_ptr, info_ptr, length);
    } while (!(png_ptr->mode & PNG_HAVE_IEND));
 }

+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */

 
 /* free all memory used by the read */
 void PNGAPI
 
 /* free all memory used by the read */
 void PNGAPI


@@ -1071,9 +1087,16 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
    png_voidp mem_ptr = NULL;
 #endif
 
    png_voidp mem_ptr = NULL;
 #endif
 

-   png_debug(1, "in png_destroy_read_struct\n");
+   png_debug(1, "in png_destroy_read_struct");

    if (png_ptr_ptr != NULL)
       png_ptr = *png_ptr_ptr;
    if (png_ptr_ptr != NULL)
       png_ptr = *png_ptr_ptr;

+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+   mem_ptr = png_ptr->mem_ptr;
+#endif

 
    if (info_ptr_ptr != NULL)
       info_ptr = *info_ptr_ptr;
 
    if (info_ptr_ptr != NULL)
       info_ptr = *info_ptr_ptr;


@@ -1081,11 +1104,6 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
    if (end_info_ptr_ptr != NULL)
       end_info_ptr = *end_info_ptr_ptr;
 
    if (end_info_ptr_ptr != NULL)
       end_info_ptr = *end_info_ptr_ptr;
 

-#ifdef PNG_USER_MEM_SUPPORTED
-   free_fn = png_ptr->free_fn;
-   mem_ptr = png_ptr->mem_ptr;
-#endif
-

    png_read_destroy(png_ptr, info_ptr, end_info_ptr);
 
    if (info_ptr != NULL)
    png_read_destroy(png_ptr, info_ptr, end_info_ptr);
 
    if (info_ptr != NULL)


@@ -1143,7 +1161,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    png_free_ptr free_fn;
 #endif
 
    png_free_ptr free_fn;
 #endif
 

-   png_debug(1, "in png_read_destroy\n");
+   png_debug(1, "in png_read_destroy");

    if (info_ptr != NULL)
       png_info_destroy(png_ptr, info_ptr);
 
    if (info_ptr != NULL)
       png_info_destroy(png_ptr, info_ptr);
 


@@ -1153,6 +1171,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    png_free(png_ptr, png_ptr->zbuf);
    png_free(png_ptr, png_ptr->big_row_buf);
    png_free(png_ptr, png_ptr->prev_row);
    png_free(png_ptr, png_ptr->zbuf);
    png_free(png_ptr, png_ptr->big_row_buf);
    png_free(png_ptr, png_ptr->prev_row);

+   png_free(png_ptr, png_ptr->chunkdata);

 #if defined(PNG_READ_DITHER_SUPPORTED)
    png_free(png_ptr, png_ptr->palette_lookup);
    png_free(png_ptr, png_ptr->dither_index);
 #if defined(PNG_READ_DITHER_SUPPORTED)
    png_free(png_ptr, png_ptr->palette_lookup);
    png_free(png_ptr, png_ptr->dither_index);


@@ -1249,7 +1268,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
     * being used again.
     */
 #ifdef PNG_SETJMP_SUPPORTED
     * being used again.
     */
 #ifdef PNG_SETJMP_SUPPORTED

-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));

 #endif
 
    error_fn = png_ptr->error_fn;
 #endif
 
    error_fn = png_ptr->error_fn;


@@ -1259,7 +1278,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    free_fn = png_ptr->free_fn;
 #endif
 
    free_fn = png_ptr->free_fn;
 #endif
 

-   png_memset(png_ptr, 0, sizeof (png_struct));
+   png_memset(png_ptr, 0, png_sizeof(png_struct));

 
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;
 
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;


@@ -1269,7 +1288,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED

-   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));

 #endif
 
 }
 #endif
 
 }


@@ -1277,9 +1296,12 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
 void PNGAPI
 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
 {
 void PNGAPI
 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
 {

+   if (png_ptr == NULL) return;

    png_ptr->read_row_fn = read_row_fn;
 }
 
    png_ptr->read_row_fn = read_row_fn;
 }
 

+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED

 #if defined(PNG_INFO_IMAGE_SUPPORTED)
 void PNGAPI
 png_read_png(png_structp png_ptr, png_infop info_ptr,
 #if defined(PNG_INFO_IMAGE_SUPPORTED)
 void PNGAPI
 png_read_png(png_structp png_ptr, png_infop info_ptr,


@@ -1288,35 +1310,40 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 {
    int row;
 
 {
    int row;
 

+   if (png_ptr == NULL) return;

 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)

-   /* invert the alpha channel from opacity to transparency */
+   /* invert the alpha channel from opacity to transparency
+    */

    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
        png_set_invert_alpha(png_ptr);
 #endif
 
    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
        png_set_invert_alpha(png_ptr);
 #endif
 

-   /* The call to png_read_info() gives us all of the information from the
+   /* png_read_info() gives us all of the information from the

     * PNG file before the first IDAT (image data chunk).
     */
    png_read_info(png_ptr, info_ptr);
     * PNG file before the first IDAT (image data chunk).
     */
    png_read_info(png_ptr, info_ptr);

+   if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+      png_error(png_ptr, "Image is too high to process with png_read_png()");

 
    /* -------------- image transformations start here ------------------- */
 
 #if defined(PNG_READ_16_TO_8_SUPPORTED)
 
    /* -------------- image transformations start here ------------------- */
 
 #if defined(PNG_READ_16_TO_8_SUPPORTED)

-   /* tell libpng to strip 16 bit/color files down to 8 bits/color */
+   /* tell libpng to strip 16 bit/color files down to 8 bits per color
+    */

    if (transforms & PNG_TRANSFORM_STRIP_16)
        png_set_strip_16(png_ptr);
 #endif
 
 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
    if (transforms & PNG_TRANSFORM_STRIP_16)
        png_set_strip_16(png_ptr);
 #endif
 
 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)

-   /* Strip alpha bytes from the input data without combining with the
-    * background (not recommended).
+   /* Strip alpha bytes from the input data without combining with
+    * the background (not recommended).

     */
    if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
        png_set_strip_alpha(png_ptr);
 #endif
 
 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
     */
    if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
        png_set_strip_alpha(png_ptr);
 #endif
 
 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)

-   /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
+   /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single

     * byte into separate bytes (useful for paletted and grayscale images).
     */
    if (transforms & PNG_TRANSFORM_PACKING)
     * byte into separate bytes (useful for paletted and grayscale images).
     */
    if (transforms & PNG_TRANSFORM_PACKING)


@@ -1325,7 +1352,8 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
    /* Change the order of packed pixels to least significant bit first
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
    /* Change the order of packed pixels to least significant bit first

-    * (not useful if you are using png_set_packing). */
+    * (not useful if you are using png_set_packing).
+    */

    if (transforms & PNG_TRANSFORM_PACKSWAP)
        png_set_packswap(png_ptr);
 #endif
    if (transforms & PNG_TRANSFORM_PACKSWAP)
        png_set_packswap(png_ptr);
 #endif


@@ -1343,10 +1371,12 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
          png_set_expand(png_ptr);
 #endif
 
          png_set_expand(png_ptr);
 #endif
 

-   /* We don't handle background color or gamma transformation or dithering. */
+   /* We don't handle background color or gamma transformation or dithering.
+    */

 
 #if defined(PNG_READ_INVERT_SUPPORTED)
 
 #if defined(PNG_READ_INVERT_SUPPORTED)

-   /* invert monochrome files to have 0 as white and 1 as black */
+   /* invert monochrome files to have 0 as white and 1 as black
+    */

    if (transforms & PNG_TRANSFORM_INVERT_MONO)
        png_set_invert_mono(png_ptr);
 #endif
    if (transforms & PNG_TRANSFORM_INVERT_MONO)
        png_set_invert_mono(png_ptr);
 #endif


@@ -1367,19 +1397,22 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #if defined(PNG_READ_BGR_SUPPORTED)
 #endif
 
 #if defined(PNG_READ_BGR_SUPPORTED)

-   /* flip the RGB pixels to BGR (or RGBA to BGRA) */
+   /* flip the RGB pixels to BGR (or RGBA to BGRA)
+    */

    if (transforms & PNG_TRANSFORM_BGR)
        png_set_bgr(png_ptr);
 #endif
 
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
    if (transforms & PNG_TRANSFORM_BGR)
        png_set_bgr(png_ptr);
 #endif
 
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)

-   /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+   /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
+    */

    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
        png_set_swap_alpha(png_ptr);
 #endif
 
 #if defined(PNG_READ_SWAP_SUPPORTED)
    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
        png_set_swap_alpha(png_ptr);
 #endif
 
 #if defined(PNG_READ_SWAP_SUPPORTED)

-   /* swap bytes of 16 bit files to least significant byte first */
+   /* swap bytes of 16 bit files to least significant byte first
+    */

    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
        png_set_swap(png_ptr);
 #endif
    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
        png_set_swap(png_ptr);
 #endif


@@ -1397,10 +1430,10 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 #ifdef PNG_FREE_ME_SUPPORTED
    png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
 #endif
 #ifdef PNG_FREE_ME_SUPPORTED
    png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
 #endif

-   if(info_ptr->row_pointers == NULL)
+   if (info_ptr->row_pointers == NULL)

    {
       info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
    {
       info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,

-         info_ptr->height * sizeof(png_bytep));
+         info_ptr->height * png_sizeof(png_bytep));

 #ifdef PNG_FREE_ME_SUPPORTED
       info_ptr->free_me |= PNG_FREE_ROWS;
 #endif
 #ifdef PNG_FREE_ME_SUPPORTED
       info_ptr->free_me |= PNG_FREE_ROWS;
 #endif


@@ -1417,8 +1450,10 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
    /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);
 
    /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);
 

-   if(transforms == 0 || params == NULL)
-      /* quiet compiler warnings */ return;
+   transforms = transforms; /* quiet compiler warnings */
+   params = params;

 
 }
 
 }

-#endif
+#endif /* PNG_INFO_IMAGE_SUPPORTED */
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */