libpng: Optimize RGBA png_do_expand_palette

third_party/libpng/pngwrite.c

 
 /* pngwrite.c - general routines to write a PNG file
  *
  * Last changed in libpng 1.6.19 [November 12, 2015]
  * Copyright (c) 1998-2002,2004,2006-2015 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
@@ skipping 919 matching lines @@
    png_debug(1, "in png_write_destroy");
 
    /* Free any memory zlib uses */
    if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
       deflateEnd(&png_ptr->zstream);
 
    /* Free our memory.  png_free checks NULL for us. */
    png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
    png_free(png_ptr, png_ptr->row_buf);
    png_ptr->row_buf = NULL;
+#ifdef PNG_READ_EXPANDED_SUPPORTED
+   png_free(png_ptr, png_ptr->row_tmp_palette);
+   png_ptr->row_tmp_palette = NULL;
+#endif
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_free(png_ptr, png_ptr->prev_row);
    png_free(png_ptr, png_ptr->try_row);
    png_free(png_ptr, png_ptr->tst_row);
    png_ptr->prev_row = NULL;
    png_ptr->try_row = NULL;
    png_ptr->tst_row = NULL;
 #endif
 
 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
@@ skipping 1424 matching lines @@
    else if (image != NULL)
       return png_image_error(image,
          "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
 
    else
       return 0;
 }
 #endif /* SIMPLIFIED_WRITE_STDIO */
 #endif /* SIMPLIFIED_WRITE */
 #endif /* WRITE */