1768       png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);  in png_write_start_row()
1769       png_memset(png_ptr->prev_row, 0, buf_size);  in png_write_start_row()
1885          if (png_ptr->prev_row != NULL)  in png_write_finish_row()
1886             png_memset(png_ptr->prev_row, 0,  in png_write_finish_row()
2113    png_bytep prev_row, best_row, row_buf;  in png_write_find_filter()  local
2125    prev_row = png_ptr->prev_row;  in png_write_find_filter()
2331            pp = prev_row + 1; i < row_bytes;  in png_write_find_filter()
2379            pp = prev_row + 1; i < row_bytes; i++)  in png_write_find_filter()
2433            pp = prev_row + 1; i < bpp; i++)  in png_write_find_filter()
2484            pp = prev_row + 1; i < bpp; i++)  in png_write_find_filter()
2545            pp = prev_row + 1; i < bpp; i++)  in png_write_find_filter()
2550       for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)  in png_write_find_filter()
2617            pp = prev_row + 1; i < bpp; i++)  in png_write_find_filter()
2624       for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)  in png_write_find_filter()
2760    if (png_ptr->prev_row != NULL)  in png_write_filtered_row()
2764       tptr = png_ptr->prev_row;  in png_write_filtered_row()
2765       png_ptr->prev_row = png_ptr->row_buf;  in png_write_filtered_row()