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src/Source/LibPNG/pngread.c  view on Meta::CPAN

/* Free all memory used in the read struct */
static void
png_read_destroy(png_structrp png_ptr)
{
   png_debug(1, "in png_read_destroy");

#ifdef PNG_READ_GAMMA_SUPPORTED
   png_destroy_gamma_table(png_ptr);
#endif

   png_free(png_ptr, png_ptr->big_row_buf);
   png_ptr->big_row_buf = NULL;
   png_free(png_ptr, png_ptr->big_prev_row);
   png_ptr->big_prev_row = NULL;
   png_free(png_ptr, png_ptr->read_buffer);
   png_ptr->read_buffer = NULL;

#ifdef PNG_READ_QUANTIZE_SUPPORTED
   png_free(png_ptr, png_ptr->palette_lookup);
   png_ptr->palette_lookup = NULL;
   png_free(png_ptr, png_ptr->quantize_index);
   png_ptr->quantize_index = NULL;
#endif

   if ((png_ptr->free_me & PNG_FREE_PLTE) != 0)
   {
      png_zfree(png_ptr, png_ptr->palette);
      png_ptr->palette = NULL;
   }
   png_ptr->free_me &= ~PNG_FREE_PLTE;

#if defined(PNG_tRNS_SUPPORTED) || \
    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
   if ((png_ptr->free_me & PNG_FREE_TRNS) != 0)
   {
      png_free(png_ptr, png_ptr->trans_alpha);
      png_ptr->trans_alpha = NULL;
   }
   png_ptr->free_me &= ~PNG_FREE_TRNS;
#endif

   inflateEnd(&png_ptr->zstream);

#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
   png_free(png_ptr, png_ptr->save_buffer);
   png_ptr->save_buffer = NULL;
#endif

#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \
   defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
   png_free(png_ptr, png_ptr->unknown_chunk.data);
   png_ptr->unknown_chunk.data = NULL;
#endif

#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
   png_free(png_ptr, png_ptr->chunk_list);
   png_ptr->chunk_list = NULL;
#endif

   /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error
    * callbacks are still set at this point.  They are required to complete the
    * destruction of the png_struct itself.
    */
}

/* Free all memory used by the read */
void PNGAPI
png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
    png_infopp end_info_ptr_ptr)
{
   png_structrp png_ptr = NULL;

   png_debug(1, "in png_destroy_read_struct");

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

   if (png_ptr == NULL)
      return;

   /* libpng 1.6.0: use the API to destroy info structs to ensure consistent
    * behavior.  Prior to 1.6.0 libpng did extra 'info' destruction in this API.
    * The extra was, apparently, unnecessary yet this hides memory leak bugs.
    */
   png_destroy_info_struct(png_ptr, end_info_ptr_ptr);
   png_destroy_info_struct(png_ptr, info_ptr_ptr);

   *png_ptr_ptr = NULL;
   png_read_destroy(png_ptr);
   png_destroy_png_struct(png_ptr);
}

void PNGAPI
png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
{
   if (png_ptr == NULL)
      return;

   png_ptr->read_row_fn = read_row_fn;
}


#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
#ifdef PNG_INFO_IMAGE_SUPPORTED
void PNGAPI
png_read_png(png_structrp png_ptr, png_inforp info_ptr,
                           int transforms,
                           voidp params)
{
   if (png_ptr == NULL || info_ptr == NULL)
      return;

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

   /* -------------- image transformations start here ------------------- */
   /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM