Xlsx Writer corrupts decimal values with commas in them

[makedin]

This is:

- [x] a bug report
- [ ] a feature request
- [x] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

Decimal values should be represented correctly (like "1.1") in Xlsx files.

What is the current behavior?

If PHP has been set to use a locale that uses comma as decimal separator, any decimal values (floats, real numbers) with a decimal part become corrupted: "1,1" (1.1) for instance becomes "1.1.0".

Note that LibreOffice Calc silently fixes values like these. Neither Microsoft Excel nor Google Sheets handle these values as decimals (Excel gives a warning and converts the value to a string. Sheets drops the value silently). PhpSpreadsheet itself silently converts the value to a string.

What are the steps to reproduce?

Please provide a Minimal, Complete, and Verifiable example of code that exhibits the issue without relying on an external Excel file or a web server:

<?php
require __DIR__ . '/vendor/autoload.php';

if (!setlocale(LC_ALL, 'fi_FI.UTF-8')) {
  die("Locale not available, this isn't going to work\n"); 
} 

$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
$spreadsheet->getActiveSheet()->setCellValue('A1', 1.1);

$filename = 'decimalcomma.xlsx';
$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($spreadsheet);
$writer->save($filename);          

$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xlsx();
$spreadsheet = $reader->load($filename);
echo($spreadsheet->getActiveSheet()->getCell('A1')->getValue());

Which versions of PhpSpreadsheet and PHP are affected?

The bug seems to have been introduced by cf30c2a. It should manifest with any supported PHP version.

[MarkBaker]

Thank you for highlighting this issue, and for the resolution