X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/a626cc03053700ca5bdbf0243831bec528e6fc4d..43f4e852a1b2ac37c3db6a2b87315192ac549191:/src/png/pngmem.c?ds=sidebyside

diff --git a/src/png/pngmem.c b/src/png/pngmem.c
index 06c4c1b7ea..bf5ff037da 100644
--- a/src/png/pngmem.c
+++ b/src/png/pngmem.c
@@ -1,11 +1,14 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * libpng 1.0.3 - January 14, 1999
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.7 [December 15, 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 file provides a location for all memory allocation.  Users who
  * need special memory handling are expected to supply replacement
@@ -14,80 +17,87 @@
  * identify the replacement functions.
  */
 
-#define PNG_INTERNAL
-#include "png.h"
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 /* Borland DOS special memory handler */
 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* if you change this, be sure to change the one in png.h also */
+/* If you change this, be sure to change the one in png.h also */
 
 /* Allocate memory for a png_struct.  The malloc and memset can be replaced
    by a single call to calloc() if this is thought to improve performance. */
-png_voidp
-png_create_struct(int type)
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct,(int type),PNG_ALLOCATED)
 {
-#ifdef PNG_USER_MEM_SUPPORTED
-   return (png_create_struct_2(type, NULL));
+#  ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL, NULL));
 }
 
 /* Alternate version of png_create_struct, for use with user-defined malloc. */
-png_voidp
-png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
+   PNG_ALLOCATED)
 {
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
    png_size_t size;
    png_voidp struct_ptr;
 
    if (type == PNG_STRUCT_INFO)
-     size = sizeof(png_info);
+      size = png_sizeof(png_info);
+
    else if (type == PNG_STRUCT_PNG)
-     size = sizeof(png_struct);
+      size = png_sizeof(png_struct);
+
    else
-     return ((png_voidp)NULL);
+      return (png_get_copyright(NULL));
 
-#ifdef PNG_USER_MEM_SUPPORTED
-   if(malloc_fn != NULL)
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (malloc_fn != NULL)
    {
-      if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
-         png_memset(struct_ptr, 0, size);
-         return (struct_ptr);
+      png_struct dummy_struct;
+      memset(&dummy_struct, 0, sizeof dummy_struct);
+      dummy_struct.mem_ptr=mem_ptr;
+      struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size);
    }
-#endif /* PNG_USER_MEM_SUPPORTED */
-   if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
-   {
+
+   else
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   struct_ptr = (png_voidp)farmalloc(size);
+   if (struct_ptr != NULL)
       png_memset(struct_ptr, 0, size);
-   }
+
    return (struct_ptr);
 }
 
-
 /* Free memory allocated by a png_create_struct() call */
-void
+void /* PRIVATE */
 png_destroy_struct(png_voidp struct_ptr)
 {
-#ifdef PNG_USER_MEM_SUPPORTED
-   png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
+#  ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, NULL, NULL);
 }
 
 /* Free memory allocated by a png_create_struct() call */
-void
-png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+    png_voidp mem_ptr)
 {
-#endif
+#  endif
    if (struct_ptr != NULL)
    {
-#ifdef PNG_USER_MEM_SUPPORTED
-      if(free_fn != NULL)
+#  ifdef PNG_USER_MEM_SUPPORTED
+      if (free_fn != NULL)
       {
          png_struct dummy_struct;
-         png_structp png_ptr = &dummy_struct;
-         (*(free_fn))(png_ptr, struct_ptr);
-         struct_ptr = NULL;
+         memset(&dummy_struct, 0, sizeof dummy_struct);
+         dummy_struct.mem_ptr=mem_ptr;
+         (*(free_fn))(&dummy_struct, struct_ptr);
          return;
       }
-#endif /* PNG_USER_MEM_SUPPORTED */
+
+#  endif /* PNG_USER_MEM_SUPPORTED */
       farfree (struct_ptr);
-      struct_ptr = NULL;
    }
 }
 
@@ -110,46 +120,76 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
  * result, we would be truncating potentially larger memory requests
  * (which should cause a fatal error) and introducing major problems.
  */
-png_voidp
-png_malloc(png_structp png_ptr, png_uint_32 size)
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 {
-#ifndef PNG_USER_MEM_SUPPORTED
    png_voidp ret;
-#endif
+
+   ret = (png_malloc(png_ptr, size));
+
+   if (ret != NULL)
+      png_memset(ret,0,(png_size_t)size);
+
+   return (ret);
+}
+
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
    if (png_ptr == NULL || size == 0)
-      return ((png_voidp)NULL);
+      return (NULL);
+
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->malloc_fn != NULL)
+      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
 
-#ifdef PNG_USER_MEM_SUPPORTED
-   if(png_ptr->malloc_fn != NULL)
-       return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
    else
-       return png_malloc_default(png_ptr, size);
+      ret = (png_malloc_default(png_ptr, size));
+
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+       png_error(png_ptr, "Out of memory");
+
+   return (ret);
 }
 
-png_voidp
-png_malloc_default(png_structp png_ptr, png_uint_32 size)
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 {
    png_voidp ret;
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
 
-#ifdef PNG_MAX_MALLOC_64K
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
+
+#  ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
-      png_error(png_ptr, "Cannot Allocate > 64K");
-#endif
+   {
+      png_warning(png_ptr, "Cannot Allocate > 64K");
+      ret = NULL;
+   }
+
+   else
+#  endif
 
-   if (size == (png_uint_32)65536L)
+   if (size != (size_t)size)
+      ret = NULL;
+
+   else if (size == (png_uint_32)65536L)
    {
       if (png_ptr->offset_table == NULL)
       {
-         /* try to see if we need to do any of this fancy stuff */
+         /* Try to see if we need to do any of this fancy stuff */
          ret = farmalloc(size);
          if (ret == NULL || ((png_size_t)ret & 0xffff))
          {
             int num_blocks;
             png_uint_32 total_size;
             png_bytep table;
-            int i;
+            int i, mem_level, window_bits;
             png_byte huge * hptr;
+            int window_bits
 
             if (ret != NULL)
             {
@@ -157,11 +197,23 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
                ret = NULL;
             }
 
-            num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
-            if (num_blocks < 1)
+            window_bits =
+                png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
+                png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
+
+            if (window_bits > 14)
+               num_blocks = (int)(1 << (window_bits - 14));
+
+            else
                num_blocks = 1;
-            if (png_ptr->zlib_mem_level >= 7)
-               num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
+
+            mem_level =
+                png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
+                png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
+
+            if (mem_level >= 7)
+               num_blocks += (int)(1 << (mem_level - 7));
+
             else
                num_blocks++;
 
@@ -171,33 +223,57 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
 
             if (table == NULL)
             {
-               png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
+#  ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */
+
+               else
+                  png_warning(png_ptr, "Out Of Memory");
+#  endif
+               return (NULL);
             }
 
             if ((png_size_t)table & 0xfff0)
             {
-               png_error(png_ptr, "Farmalloc didn't return normalized pointer");
+#  ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr,
+                    "Farmalloc didn't return normalized pointer");
+
+               else
+                  png_warning(png_ptr,
+                    "Farmalloc didn't return normalized pointer");
+#  endif
+               return (NULL);
             }
 
             png_ptr->offset_table = table;
             png_ptr->offset_table_ptr = farmalloc(num_blocks *
-               sizeof (png_bytep));
+               png_sizeof(png_bytep));
 
             if (png_ptr->offset_table_ptr == NULL)
             {
-               png_error(png_ptr, "Out Of memory.");
+#  ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */
+
+               else
+                  png_warning(png_ptr, "Out Of memory");
+#  endif
+               return (NULL);
             }
 
             hptr = (png_byte huge *)table;
             if ((png_size_t)hptr & 0xf)
             {
                hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-               hptr += 16L;
+               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
             }
+
             for (i = 0; i < num_blocks; i++)
             {
                png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-               hptr += (png_uint_32)65536L;
+               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
             }
 
             png_ptr->offset_table_number = num_blocks;
@@ -207,44 +283,65 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
       }
 
       if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
-         png_error(png_ptr, "Out of Memory.");
+      {
+#  ifndef PNG_USER_MEM_SUPPORTED
+         if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+            png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */
+
+         else
+            png_warning(png_ptr, "Out of Memory");
+#  endif
+         return (NULL);
+      }
 
       ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
    }
+
    else
       ret = farmalloc(size);
 
+#  ifndef PNG_USER_MEM_SUPPORTED
    if (ret == NULL)
    {
-      png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+         png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
+
+      else
+         png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
    }
+#  endif
 
    return (ret);
 }
 
-/* free a pointer allocated by png_malloc().  In the default
-   configuration, png_ptr is not used, but is passed in case it
-   is needed.  If ptr is NULL, return without taking any action. */
-void
+/* Free a pointer allocated by png_malloc().  In the default
+ * configuration, png_ptr is not used, but is passed in case it
+ * is needed.  If ptr is NULL, return without taking any action.
+ */
+void PNGAPI
 png_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
-#ifdef PNG_USER_MEM_SUPPORTED
+#  ifdef PNG_USER_MEM_SUPPORTED
    if (png_ptr->free_fn != NULL)
    {
       (*(png_ptr->free_fn))(png_ptr, ptr);
-      ptr = NULL;
       return;
    }
-   else png_free_default(png_ptr, ptr);
+
+   else
+      png_free_default(png_ptr, ptr);
 }
 
-void
+void PNGAPI
 png_free_default(png_structp png_ptr, png_voidp ptr)
 {
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
+
+   if (png_ptr == NULL || ptr == NULL)
+      return;
 
    if (png_ptr->offset_table != NULL)
    {
@@ -269,243 +366,302 @@ png_free_default(png_structp png_ptr, png_voidp ptr)
    }
 
    if (ptr != NULL)
-   {
       farfree(ptr);
-      ptr = NULL;
-   }
 }
 
 #else /* Not the Borland DOS special memory handler */
 
 /* Allocate memory for a png_struct or a png_info.  The malloc and
    memset can be replaced by a single call to calloc() if this is thought
-   to improve performance noticably.*/
-png_voidp
-png_create_struct(int type)
+   to improve performance noticably. */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct,(int type),PNG_ALLOCATED)
 {
-#ifdef PNG_USER_MEM_SUPPORTED
-   return (png_create_struct_2(type, NULL));
+#  ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL, NULL));
 }
 
 /* Allocate memory for a png_struct or a png_info.  The malloc and
    memset can be replaced by a single call to calloc() if this is thought
-   to improve performance noticably.*/
-png_voidp
-png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+   to improve performance noticably. */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
+   PNG_ALLOCATED)
 {
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
    png_size_t size;
    png_voidp struct_ptr;
 
    if (type == PNG_STRUCT_INFO)
-      size = sizeof(png_info);
+      size = png_sizeof(png_info);
+
    else if (type == PNG_STRUCT_PNG)
-      size = sizeof(png_struct);
+      size = png_sizeof(png_struct);
+
    else
-      return ((png_voidp)NULL);
+      return (NULL);
 
-#ifdef PNG_USER_MEM_SUPPORTED
-   if(malloc_fn != NULL)
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (malloc_fn != NULL)
    {
-      if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
+      png_struct dummy_struct;
+      png_structp png_ptr = &dummy_struct;
+      png_ptr->mem_ptr=mem_ptr;
+      struct_ptr = (*(malloc_fn))(png_ptr, size);
+
+      if (struct_ptr != NULL)
          png_memset(struct_ptr, 0, size);
+
       return (struct_ptr);
    }
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
+
+#  if defined(__TURBOC__) && !defined(__FLAT__)
+   struct_ptr = (png_voidp)farmalloc(size);
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
+   struct_ptr = (png_voidp)halloc(size, 1);
+#    else
+   struct_ptr = (png_voidp)malloc(size);
+#    endif
+#  endif
 
-#if defined(__TURBOC__) && !defined(__FLAT__)
-   if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
-   if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL)
-# else
-   if ((struct_ptr = (png_voidp)malloc(size)) != NULL)
-# endif
-#endif
-   {
+   if (struct_ptr != NULL)
       png_memset(struct_ptr, 0, size);
-   }
 
    return (struct_ptr);
 }
 
 
 /* Free memory allocated by a png_create_struct() call */
-void
+void /* PRIVATE */
 png_destroy_struct(png_voidp struct_ptr)
 {
-#ifdef PNG_USER_MEM_SUPPORTED
-   png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
+#  ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, NULL, NULL);
 }
 
 /* Free memory allocated by a png_create_struct() call */
-void
-png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+    png_voidp mem_ptr)
 {
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
    if (struct_ptr != NULL)
    {
-#ifdef PNG_USER_MEM_SUPPORTED
-      if(free_fn != NULL)
+#  ifdef PNG_USER_MEM_SUPPORTED
+      if (free_fn != NULL)
       {
          png_struct dummy_struct;
          png_structp png_ptr = &dummy_struct;
+         png_ptr->mem_ptr=mem_ptr;
          (*(free_fn))(png_ptr, struct_ptr);
-         struct_ptr = NULL;
          return;
       }
-#endif /* PNG_USER_MEM_SUPPORTED */
-#if defined(__TURBOC__) && !defined(__FLAT__)
+#  endif /* PNG_USER_MEM_SUPPORTED */
+#  if defined(__TURBOC__) && !defined(__FLAT__)
       farfree(struct_ptr);
-      struct_ptr = NULL;
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
+
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
       hfree(struct_ptr);
-      struct_ptr = NULL;
-# else
+
+#    else
       free(struct_ptr);
-      struct_ptr = NULL;
-# endif
-#endif
+
+#    endif
+#  endif
    }
 }
 
-
 /* 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. */
+ * 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.
+ */
+
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
+   ret = (png_malloc(png_ptr, size));
+
+   if (ret != NULL)
+      png_memset(ret,0,(png_size_t)size);
+
+   return (ret);
+}
 
-png_voidp
-png_malloc(png_structp png_ptr, png_uint_32 size)
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 {
-#ifndef PNG_USER_MEM_SUPPORTED
    png_voidp ret;
-#endif
+
+#  ifdef PNG_USER_MEM_SUPPORTED
    if (png_ptr == NULL || size == 0)
-      return ((png_voidp)NULL);
+      return (NULL);
+
+   if (png_ptr->malloc_fn != NULL)
+      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
 
-#ifdef PNG_USER_MEM_SUPPORTED
-   if(png_ptr->malloc_fn != NULL)
-       return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
    else
-       return (png_malloc_default(png_ptr, size));
+      ret = (png_malloc_default(png_ptr, size));
+
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+       png_error(png_ptr, "Out of Memory");
+
+   return (ret);
 }
-png_voidp
-png_malloc_default(png_structp png_ptr, png_uint_32 size)
+
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 {
    png_voidp ret;
-#endif /* PNG_USER_MEM_SUPPORTED */
+#  endif /* PNG_USER_MEM_SUPPORTED */
 
-#ifdef PNG_MAX_MALLOC_64K
-   if (size > (png_uint_32)65536L)
-      png_error(png_ptr, "Cannot Allocate > 64K");
-#endif
-
-#if defined(__TURBOC__) && !defined(__FLAT__)
-   ret = farmalloc(size);
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
-   ret = halloc(size, 1);
-# else
-   ret = malloc((size_t)size);
-# endif
-#endif
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
 
-   if (ret == NULL)
+#  ifdef PNG_MAX_MALLOC_64K
+   if (size > (png_uint_32)65536L)
    {
-      png_error(png_ptr, "Out of Memory");
+#    ifndef PNG_USER_MEM_SUPPORTED
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+         png_error(png_ptr, "Cannot Allocate > 64K");
+
+      else
+#    endif
+         return NULL;
    }
+#  endif
+
+   /* Check for overflow */
+#  if defined(__TURBOC__) && !defined(__FLAT__)
+
+   if (size != (unsigned long)size)
+      ret = NULL;
+
+   else
+      ret = farmalloc(size);
+
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
+   if (size != (unsigned long)size)
+      ret = NULL;
+
+   else
+      ret = halloc(size, 1);
+
+#    else
+   if (size != (size_t)size)
+      ret = NULL;
+
+   else
+      ret = malloc((size_t)size);
+#    endif
+#  endif
+
+#  ifndef PNG_USER_MEM_SUPPORTED
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+      png_error(png_ptr, "Out of Memory");
+#  endif
 
    return (ret);
 }
 
 /* Free a pointer allocated by png_malloc().  If ptr is NULL, return
-   without taking any action. */
-void
+ * without taking any action.
+ */
+void PNGAPI
 png_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
-#ifdef PNG_USER_MEM_SUPPORTED
+#  ifdef PNG_USER_MEM_SUPPORTED
    if (png_ptr->free_fn != NULL)
    {
       (*(png_ptr->free_fn))(png_ptr, ptr);
-      ptr = NULL;
       return;
    }
-   else png_free_default(png_ptr, ptr);
+
+   else
+      png_free_default(png_ptr, ptr);
 }
-void
+
+void PNGAPI
 png_free_default(png_structp png_ptr, png_voidp ptr)
 {
-#endif /* PNG_USER_MEM_SUPPORTED */
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
+#  endif /* PNG_USER_MEM_SUPPORTED */
 
-#if defined(__TURBOC__) && !defined(__FLAT__)
+#  if defined(__TURBOC__) && !defined(__FLAT__)
    farfree(ptr);
-   ptr = NULL;
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
+
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
    hfree(ptr);
-   ptr = NULL;
-# else
+
+#    else
    free(ptr);
-   ptr = NULL;
-# endif
-#endif
-}
 
+#    endif
+#  endif
+}
 #endif /* Not Borland DOS special memory handler */
 
-png_voidp
-png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
-   png_uint_32 length)
+/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
+ * function will set up png_malloc() to issue a png_warning and return NULL
+ * instead of issuing a png_error, if it fails to allocate the requested
+ * memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 {
-   png_size_t size;
-
-   size = (png_size_t)length;
-   if ((png_uint_32)size != length)
-      png_error(png_ptr,"Overflow in png_memcpy_check.");
-
-   return(png_memcpy (s1, s2, size));
+   png_voidp ptr;
+   png_uint_32 save_flags;
+   if (png_ptr == NULL)
+      return (NULL);
+
+   save_flags = png_ptr->flags;
+   png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+   ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
+   png_ptr->flags=save_flags;
+   return(ptr);
 }
 
-png_voidp
-png_memset_check (png_structp png_ptr, png_voidp s1, int value,
-   png_uint_32 length)
-{
-   png_size_t size;
-
-   size = (png_size_t)length;
-   if ((png_uint_32)size != length)
-      png_error(png_ptr,"Overflow in png_memset_check.");
-
-   return (png_memset (s1, value, size));
-
-}
 
 #ifdef PNG_USER_MEM_SUPPORTED
 /* This function is called when the application wants to use another method
  * of allocating and freeing memory.
  */
-void
+void PNGAPI
 png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
   malloc_fn, png_free_ptr free_fn)
 {
-   png_ptr->mem_ptr = mem_ptr;
-   png_ptr->malloc_fn = malloc_fn;
-   png_ptr->free_fn = free_fn;
+   if (png_ptr != NULL)
+   {
+      png_ptr->mem_ptr = mem_ptr;
+      png_ptr->malloc_fn = malloc_fn;
+      png_ptr->free_fn = free_fn;
+   }
 }
 
 /* This function returns a pointer to the mem_ptr associated with the user
  * functions.  The application should free any memory associated with this
  * pointer before png_write_destroy and png_read_destroy are called.
  */
-png_voidp
-png_get_mem_ptr(png_structp png_ptr)
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structp png_ptr)
 {
+   if (png_ptr == NULL)
+      return (NULL);
+
    return ((png_voidp)png_ptr->mem_ptr);
 }
 #endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */