[php-src] Issue #8563: Different results for seek() on SplFileObject and SplTempFileObject

Issue: https://github.com/php/php-src/issues/8563 Author: gabrielpl ### Description The following [code](https://3v4l.org/DXe8i): ```php <?php declare(strict_types=1); const LINES = 5; const INDEX = 10; $file_01 = new SplTempFileObject(); $file_02 = new SplFileObject('/tmp/test.txt', 'w+'); // write to files for ($i = 0; $i < LINES; $i++) { $file_01->fwrite("line {$i}" . PHP_EOL); $file_02->fwrite("line {$i}" . PHP_EOL); } // reset $file_01->rewind(); $file_02->rewind(); // seek $file_01->seek(INDEX); $file_02->seek(INDEX); // show results echo 'file_01: ' . $file_01->key(), PHP_EOL; echo 'file_02: ' . $file_02->key(), PHP_EOL; ``` Resulted in this output: ``` file_01: 4 file_02: 5 ``` But I expected this output instead: ``` file_01: 5 file_02: 5 ``` ### PHP Version PHP 8.1.6 ### Operating System Windows 11