/* This is an internal routine to free any memory that the info struct is
 * pointing to before re-using it or freeing the struct itself.  Recall
 * that png_free() checks for NULL pointers for us.
 */
void /* PRIVATE */
png_info_destroy(png_structp png_ptr, png_infop info_ptr)
{
   png_debug(1, "in png_info_destroy\n");

   png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
   if (png_ptr->num_chunk_list)
   {
       png_free(png_ptr, png_ptr->chunk_list);
       png_ptr->chunk_list=NULL;
       png_ptr->num_chunk_list=0;
   }
#endif

   png_info_init_3(&info_ptr, png_sizeof(png_info));
}

/* Allocate the memory for an info_struct for the application.  We don't
 * really need the png_ptr, but it could potentially be useful in the
 * future.  This should be used in favour of malloc(png_sizeof(png_info))
 * and png_info_init() so that applications that want to use a shared
 * libpng don't have to be recompiled if png_info changes size.
 */
png_infop PNGAPI
png_create_info_struct(png_structp png_ptr)
{
   png_infop info_ptr;

   png_debug(1, "in png_create_info_struct\n");
   if(png_ptr == NULL) return (NULL);
#ifdef PNG_USER_MEM_SUPPORTED
   info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
      png_ptr->malloc_fn, png_ptr->mem_ptr);
#else
   info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
#endif
   if (info_ptr != NULL)
      png_info_init_3(&info_ptr, png_sizeof(png_info));

   return (info_ptr);
}

void PNGAPI
png_info_init(png_infop info_ptr)
{
   /* We only come here via pre-1.0.12-compiled applications */
   png_info_init_3(&info_ptr, 0);
}