当 SAT扇区数正好等于109时，生成的 xls 文件有问题

[lanxikun]

测试用例：

$spreadsheet = new Spreadsheet();
$sheet = $spreadsheet->setActiveSheetIndex(0);
$s = str_repeat('A', 512);
for($i = 1; $i <= 63000; $i++) {
  $sheet->setCellValue("A$i", $s);
  $sheet->setCellValue("B$i", $s);
  $sheet->setCellValue("C$i", $s);
  $sheet->setCellValue("D$i", $s);
  $sheet->setCellValue("E$i", $s);
  $sheet->setCellValue("F$i", $s);
  $sheet->setCellValue("G$i", $s);
  $sheet->setCellValue("H$i", $s);
}
$writer = IOFactory::createWriter($spreadsheet, 'Xls');
$writer->save('1.xls');

Excel 打开此文件时会提示：“发现1.xls中的部分内容有问题，是否让我们尽量尝试恢复？...”
更改循环中的 63000 为 62000 或 64000 ，则 生成的xls文件都可以正常打开，不会有出错提示

[oleibman]

Translating for my own benefit, using Google Translate.

When the SAT sector count is exactly 109, the generated xls file has a problem.

Excel will display the message: "Some content in 1.xls has been found to be incorrect. Would you like us to try to recover it?" when opening this file. Changing the 63000 in the loop to 62000 or 64000 will allow the generated xls files to be opened normally without any error messages.

[oleibman]

Confirmed - problem with 63,000, no problem with 64,000.

What is "SAT sector count"?

I know this isn't a particularly satisfactory answer, but this seems to me way more likely to be an issue with Excel rather than PhpSpreadsheet. I can't tell from the error message what they are objecting to - I think you need to take this up with Microsoft. Why do I think that?

• Despite the fact that Excel claims to have repaired the file, it looks exactly as I would expect after the "repair".
• I can open the file in LibreOffice with no problem.
• I can open the file in Gnumeric with no problem.
• I can open the file in Google Sheets with no problem.

As a workaround, if you truly need one, try saving as Xlsx rather than Xls.

[lanxikun]

Total number of sectors used for the sector allocation table (SAT) is a concept in the Microsoft Compound Document File Format. Please refer to the following documentation:
https://www.openoffice.org/sc/compdocfileformat.pdf
109 is also a magic number in this document structure.

[oleibman]

Thank you for the link. I see the magic value of 109 in one program Shared\OLE.php, which is used by the Reader, not the Writer. Perhaps something needs to change in Shared\OLE\PPS\Root.php. Even if I were to know what that is, I would be reluctant to make such a change. It seems inherently untestable since the error shows up only when the file is opened in Excel, and I would be very concerned about regression problems. I again fall back on this being a Microsoft problem.